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/* Common subexpression elimination for GNU compiler.
/* Common subexpression elimination for GNU compiler.
   Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998
   Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998
   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
 
 
This file is part of GCC.
This file is part of GCC.
 
 
GCC is free software; you can redistribute it and/or modify it under
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
Software Foundation; either version 3, or (at your option) any later
version.
version.
 
 
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.
for more details.
 
 
You should have received a copy of the GNU General Public License
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */
<http://www.gnu.org/licenses/>.  */
 
 
#include "config.h"
#include "config.h"
/* stdio.h must precede rtl.h for FFS.  */
/* stdio.h must precede rtl.h for FFS.  */
#include "system.h"
#include "system.h"
#include "coretypes.h"
#include "coretypes.h"
#include "tm.h"
#include "tm.h"
#include "rtl.h"
#include "rtl.h"
#include "tm_p.h"
#include "tm_p.h"
#include "hard-reg-set.h"
#include "hard-reg-set.h"
#include "regs.h"
#include "regs.h"
#include "basic-block.h"
#include "basic-block.h"
#include "flags.h"
#include "flags.h"
#include "real.h"
#include "real.h"
#include "insn-config.h"
#include "insn-config.h"
#include "recog.h"
#include "recog.h"
#include "function.h"
#include "function.h"
#include "expr.h"
#include "expr.h"
#include "toplev.h"
#include "toplev.h"
#include "output.h"
#include "output.h"
#include "ggc.h"
#include "ggc.h"
#include "timevar.h"
#include "timevar.h"
#include "except.h"
#include "except.h"
#include "target.h"
#include "target.h"
#include "params.h"
#include "params.h"
#include "rtlhooks-def.h"
#include "rtlhooks-def.h"
#include "tree-pass.h"
#include "tree-pass.h"
 
 
/* The basic idea of common subexpression elimination is to go
/* The basic idea of common subexpression elimination is to go
   through the code, keeping a record of expressions that would
   through the code, keeping a record of expressions that would
   have the same value at the current scan point, and replacing
   have the same value at the current scan point, and replacing
   expressions encountered with the cheapest equivalent expression.
   expressions encountered with the cheapest equivalent expression.
 
 
   It is too complicated to keep track of the different possibilities
   It is too complicated to keep track of the different possibilities
   when control paths merge in this code; so, at each label, we forget all
   when control paths merge in this code; so, at each label, we forget all
   that is known and start fresh.  This can be described as processing each
   that is known and start fresh.  This can be described as processing each
   extended basic block separately.  We have a separate pass to perform
   extended basic block separately.  We have a separate pass to perform
   global CSE.
   global CSE.
 
 
   Note CSE can turn a conditional or computed jump into a nop or
   Note CSE can turn a conditional or computed jump into a nop or
   an unconditional jump.  When this occurs we arrange to run the jump
   an unconditional jump.  When this occurs we arrange to run the jump
   optimizer after CSE to delete the unreachable code.
   optimizer after CSE to delete the unreachable code.
 
 
   We use two data structures to record the equivalent expressions:
   We use two data structures to record the equivalent expressions:
   a hash table for most expressions, and a vector of "quantity
   a hash table for most expressions, and a vector of "quantity
   numbers" to record equivalent (pseudo) registers.
   numbers" to record equivalent (pseudo) registers.
 
 
   The use of the special data structure for registers is desirable
   The use of the special data structure for registers is desirable
   because it is faster.  It is possible because registers references
   because it is faster.  It is possible because registers references
   contain a fairly small number, the register number, taken from
   contain a fairly small number, the register number, taken from
   a contiguously allocated series, and two register references are
   a contiguously allocated series, and two register references are
   identical if they have the same number.  General expressions
   identical if they have the same number.  General expressions
   do not have any such thing, so the only way to retrieve the
   do not have any such thing, so the only way to retrieve the
   information recorded on an expression other than a register
   information recorded on an expression other than a register
   is to keep it in a hash table.
   is to keep it in a hash table.
 
 
Registers and "quantity numbers":
Registers and "quantity numbers":
 
 
   At the start of each basic block, all of the (hardware and pseudo)
   At the start of each basic block, all of the (hardware and pseudo)
   registers used in the function are given distinct quantity
   registers used in the function are given distinct quantity
   numbers to indicate their contents.  During scan, when the code
   numbers to indicate their contents.  During scan, when the code
   copies one register into another, we copy the quantity number.
   copies one register into another, we copy the quantity number.
   When a register is loaded in any other way, we allocate a new
   When a register is loaded in any other way, we allocate a new
   quantity number to describe the value generated by this operation.
   quantity number to describe the value generated by this operation.
   `REG_QTY (N)' records what quantity register N is currently thought
   `REG_QTY (N)' records what quantity register N is currently thought
   of as containing.
   of as containing.
 
 
   All real quantity numbers are greater than or equal to zero.
   All real quantity numbers are greater than or equal to zero.
   If register N has not been assigned a quantity, `REG_QTY (N)' will
   If register N has not been assigned a quantity, `REG_QTY (N)' will
   equal -N - 1, which is always negative.
   equal -N - 1, which is always negative.
 
 
   Quantity numbers below zero do not exist and none of the `qty_table'
   Quantity numbers below zero do not exist and none of the `qty_table'
   entries should be referenced with a negative index.
   entries should be referenced with a negative index.
 
 
   We also maintain a bidirectional chain of registers for each
   We also maintain a bidirectional chain of registers for each
   quantity number.  The `qty_table` members `first_reg' and `last_reg',
   quantity number.  The `qty_table` members `first_reg' and `last_reg',
   and `reg_eqv_table' members `next' and `prev' hold these chains.
   and `reg_eqv_table' members `next' and `prev' hold these chains.
 
 
   The first register in a chain is the one whose lifespan is least local.
   The first register in a chain is the one whose lifespan is least local.
   Among equals, it is the one that was seen first.
   Among equals, it is the one that was seen first.
   We replace any equivalent register with that one.
   We replace any equivalent register with that one.
 
 
   If two registers have the same quantity number, it must be true that
   If two registers have the same quantity number, it must be true that
   REG expressions with qty_table `mode' must be in the hash table for both
   REG expressions with qty_table `mode' must be in the hash table for both
   registers and must be in the same class.
   registers and must be in the same class.
 
 
   The converse is not true.  Since hard registers may be referenced in
   The converse is not true.  Since hard registers may be referenced in
   any mode, two REG expressions might be equivalent in the hash table
   any mode, two REG expressions might be equivalent in the hash table
   but not have the same quantity number if the quantity number of one
   but not have the same quantity number if the quantity number of one
   of the registers is not the same mode as those expressions.
   of the registers is not the same mode as those expressions.
 
 
Constants and quantity numbers
Constants and quantity numbers
 
 
   When a quantity has a known constant value, that value is stored
   When a quantity has a known constant value, that value is stored
   in the appropriate qty_table `const_rtx'.  This is in addition to
   in the appropriate qty_table `const_rtx'.  This is in addition to
   putting the constant in the hash table as is usual for non-regs.
   putting the constant in the hash table as is usual for non-regs.
 
 
   Whether a reg or a constant is preferred is determined by the configuration
   Whether a reg or a constant is preferred is determined by the configuration
   macro CONST_COSTS and will often depend on the constant value.  In any
   macro CONST_COSTS and will often depend on the constant value.  In any
   event, expressions containing constants can be simplified, by fold_rtx.
   event, expressions containing constants can be simplified, by fold_rtx.
 
 
   When a quantity has a known nearly constant value (such as an address
   When a quantity has a known nearly constant value (such as an address
   of a stack slot), that value is stored in the appropriate qty_table
   of a stack slot), that value is stored in the appropriate qty_table
   `const_rtx'.
   `const_rtx'.
 
 
   Integer constants don't have a machine mode.  However, cse
   Integer constants don't have a machine mode.  However, cse
   determines the intended machine mode from the destination
   determines the intended machine mode from the destination
   of the instruction that moves the constant.  The machine mode
   of the instruction that moves the constant.  The machine mode
   is recorded in the hash table along with the actual RTL
   is recorded in the hash table along with the actual RTL
   constant expression so that different modes are kept separate.
   constant expression so that different modes are kept separate.
 
 
Other expressions:
Other expressions:
 
 
   To record known equivalences among expressions in general
   To record known equivalences among expressions in general
   we use a hash table called `table'.  It has a fixed number of buckets
   we use a hash table called `table'.  It has a fixed number of buckets
   that contain chains of `struct table_elt' elements for expressions.
   that contain chains of `struct table_elt' elements for expressions.
   These chains connect the elements whose expressions have the same
   These chains connect the elements whose expressions have the same
   hash codes.
   hash codes.
 
 
   Other chains through the same elements connect the elements which
   Other chains through the same elements connect the elements which
   currently have equivalent values.
   currently have equivalent values.
 
 
   Register references in an expression are canonicalized before hashing
   Register references in an expression are canonicalized before hashing
   the expression.  This is done using `reg_qty' and qty_table `first_reg'.
   the expression.  This is done using `reg_qty' and qty_table `first_reg'.
   The hash code of a register reference is computed using the quantity
   The hash code of a register reference is computed using the quantity
   number, not the register number.
   number, not the register number.
 
 
   When the value of an expression changes, it is necessary to remove from the
   When the value of an expression changes, it is necessary to remove from the
   hash table not just that expression but all expressions whose values
   hash table not just that expression but all expressions whose values
   could be different as a result.
   could be different as a result.
 
 
     1. If the value changing is in memory, except in special cases
     1. If the value changing is in memory, except in special cases
     ANYTHING referring to memory could be changed.  That is because
     ANYTHING referring to memory could be changed.  That is because
     nobody knows where a pointer does not point.
     nobody knows where a pointer does not point.
     The function `invalidate_memory' removes what is necessary.
     The function `invalidate_memory' removes what is necessary.
 
 
     The special cases are when the address is constant or is
     The special cases are when the address is constant or is
     a constant plus a fixed register such as the frame pointer
     a constant plus a fixed register such as the frame pointer
     or a static chain pointer.  When such addresses are stored in,
     or a static chain pointer.  When such addresses are stored in,
     we can tell exactly which other such addresses must be invalidated
     we can tell exactly which other such addresses must be invalidated
     due to overlap.  `invalidate' does this.
     due to overlap.  `invalidate' does this.
     All expressions that refer to non-constant
     All expressions that refer to non-constant
     memory addresses are also invalidated.  `invalidate_memory' does this.
     memory addresses are also invalidated.  `invalidate_memory' does this.
 
 
     2. If the value changing is a register, all expressions
     2. If the value changing is a register, all expressions
     containing references to that register, and only those,
     containing references to that register, and only those,
     must be removed.
     must be removed.
 
 
   Because searching the entire hash table for expressions that contain
   Because searching the entire hash table for expressions that contain
   a register is very slow, we try to figure out when it isn't necessary.
   a register is very slow, we try to figure out when it isn't necessary.
   Precisely, this is necessary only when expressions have been
   Precisely, this is necessary only when expressions have been
   entered in the hash table using this register, and then the value has
   entered in the hash table using this register, and then the value has
   changed, and then another expression wants to be added to refer to
   changed, and then another expression wants to be added to refer to
   the register's new value.  This sequence of circumstances is rare
   the register's new value.  This sequence of circumstances is rare
   within any one basic block.
   within any one basic block.
 
 
   `REG_TICK' and `REG_IN_TABLE', accessors for members of
   `REG_TICK' and `REG_IN_TABLE', accessors for members of
   cse_reg_info, are used to detect this case.  REG_TICK (i) is
   cse_reg_info, are used to detect this case.  REG_TICK (i) is
   incremented whenever a value is stored in register i.
   incremented whenever a value is stored in register i.
   REG_IN_TABLE (i) holds -1 if no references to register i have been
   REG_IN_TABLE (i) holds -1 if no references to register i have been
   entered in the table; otherwise, it contains the value REG_TICK (i)
   entered in the table; otherwise, it contains the value REG_TICK (i)
   had when the references were entered.  If we want to enter a
   had when the references were entered.  If we want to enter a
   reference and REG_IN_TABLE (i) != REG_TICK (i), we must scan and
   reference and REG_IN_TABLE (i) != REG_TICK (i), we must scan and
   remove old references.  Until we want to enter a new entry, the
   remove old references.  Until we want to enter a new entry, the
   mere fact that the two vectors don't match makes the entries be
   mere fact that the two vectors don't match makes the entries be
   ignored if anyone tries to match them.
   ignored if anyone tries to match them.
 
 
   Registers themselves are entered in the hash table as well as in
   Registers themselves are entered in the hash table as well as in
   the equivalent-register chains.  However, `REG_TICK' and
   the equivalent-register chains.  However, `REG_TICK' and
   `REG_IN_TABLE' do not apply to expressions which are simple
   `REG_IN_TABLE' do not apply to expressions which are simple
   register references.  These expressions are removed from the table
   register references.  These expressions are removed from the table
   immediately when they become invalid, and this can be done even if
   immediately when they become invalid, and this can be done even if
   we do not immediately search for all the expressions that refer to
   we do not immediately search for all the expressions that refer to
   the register.
   the register.
 
 
   A CLOBBER rtx in an instruction invalidates its operand for further
   A CLOBBER rtx in an instruction invalidates its operand for further
   reuse.  A CLOBBER or SET rtx whose operand is a MEM:BLK
   reuse.  A CLOBBER or SET rtx whose operand is a MEM:BLK
   invalidates everything that resides in memory.
   invalidates everything that resides in memory.
 
 
Related expressions:
Related expressions:
 
 
   Constant expressions that differ only by an additive integer
   Constant expressions that differ only by an additive integer
   are called related.  When a constant expression is put in
   are called related.  When a constant expression is put in
   the table, the related expression with no constant term
   the table, the related expression with no constant term
   is also entered.  These are made to point at each other
   is also entered.  These are made to point at each other
   so that it is possible to find out if there exists any
   so that it is possible to find out if there exists any
   register equivalent to an expression related to a given expression.  */
   register equivalent to an expression related to a given expression.  */
 
 
/* Length of qty_table vector.  We know in advance we will not need
/* Length of qty_table vector.  We know in advance we will not need
   a quantity number this big.  */
   a quantity number this big.  */
 
 
static int max_qty;
static int max_qty;
 
 
/* Next quantity number to be allocated.
/* Next quantity number to be allocated.
   This is 1 + the largest number needed so far.  */
   This is 1 + the largest number needed so far.  */
 
 
static int next_qty;
static int next_qty;
 
 
/* Per-qty information tracking.
/* Per-qty information tracking.
 
 
   `first_reg' and `last_reg' track the head and tail of the
   `first_reg' and `last_reg' track the head and tail of the
   chain of registers which currently contain this quantity.
   chain of registers which currently contain this quantity.
 
 
   `mode' contains the machine mode of this quantity.
   `mode' contains the machine mode of this quantity.
 
 
   `const_rtx' holds the rtx of the constant value of this
   `const_rtx' holds the rtx of the constant value of this
   quantity, if known.  A summations of the frame/arg pointer
   quantity, if known.  A summations of the frame/arg pointer
   and a constant can also be entered here.  When this holds
   and a constant can also be entered here.  When this holds
   a known value, `const_insn' is the insn which stored the
   a known value, `const_insn' is the insn which stored the
   constant value.
   constant value.
 
 
   `comparison_{code,const,qty}' are used to track when a
   `comparison_{code,const,qty}' are used to track when a
   comparison between a quantity and some constant or register has
   comparison between a quantity and some constant or register has
   been passed.  In such a case, we know the results of the comparison
   been passed.  In such a case, we know the results of the comparison
   in case we see it again.  These members record a comparison that
   in case we see it again.  These members record a comparison that
   is known to be true.  `comparison_code' holds the rtx code of such
   is known to be true.  `comparison_code' holds the rtx code of such
   a comparison, else it is set to UNKNOWN and the other two
   a comparison, else it is set to UNKNOWN and the other two
   comparison members are undefined.  `comparison_const' holds
   comparison members are undefined.  `comparison_const' holds
   the constant being compared against, or zero if the comparison
   the constant being compared against, or zero if the comparison
   is not against a constant.  `comparison_qty' holds the quantity
   is not against a constant.  `comparison_qty' holds the quantity
   being compared against when the result is known.  If the comparison
   being compared against when the result is known.  If the comparison
   is not with a register, `comparison_qty' is -1.  */
   is not with a register, `comparison_qty' is -1.  */
 
 
struct qty_table_elem
struct qty_table_elem
{
{
  rtx const_rtx;
  rtx const_rtx;
  rtx const_insn;
  rtx const_insn;
  rtx comparison_const;
  rtx comparison_const;
  int comparison_qty;
  int comparison_qty;
  unsigned int first_reg, last_reg;
  unsigned int first_reg, last_reg;
  /* The sizes of these fields should match the sizes of the
  /* The sizes of these fields should match the sizes of the
     code and mode fields of struct rtx_def (see rtl.h).  */
     code and mode fields of struct rtx_def (see rtl.h).  */
  ENUM_BITFIELD(rtx_code) comparison_code : 16;
  ENUM_BITFIELD(rtx_code) comparison_code : 16;
  ENUM_BITFIELD(machine_mode) mode : 8;
  ENUM_BITFIELD(machine_mode) mode : 8;
};
};
 
 
/* The table of all qtys, indexed by qty number.  */
/* The table of all qtys, indexed by qty number.  */
static struct qty_table_elem *qty_table;
static struct qty_table_elem *qty_table;
 
 
/* Structure used to pass arguments via for_each_rtx to function
/* Structure used to pass arguments via for_each_rtx to function
   cse_change_cc_mode.  */
   cse_change_cc_mode.  */
struct change_cc_mode_args
struct change_cc_mode_args
{
{
  rtx insn;
  rtx insn;
  rtx newreg;
  rtx newreg;
};
};
 
 
#ifdef HAVE_cc0
#ifdef HAVE_cc0
/* For machines that have a CC0, we do not record its value in the hash
/* For machines that have a CC0, we do not record its value in the hash
   table since its use is guaranteed to be the insn immediately following
   table since its use is guaranteed to be the insn immediately following
   its definition and any other insn is presumed to invalidate it.
   its definition and any other insn is presumed to invalidate it.
 
 
   Instead, we store below the value last assigned to CC0.  If it should
   Instead, we store below the value last assigned to CC0.  If it should
   happen to be a constant, it is stored in preference to the actual
   happen to be a constant, it is stored in preference to the actual
   assigned value.  In case it is a constant, we store the mode in which
   assigned value.  In case it is a constant, we store the mode in which
   the constant should be interpreted.  */
   the constant should be interpreted.  */
 
 
static rtx prev_insn_cc0;
static rtx prev_insn_cc0;
static enum machine_mode prev_insn_cc0_mode;
static enum machine_mode prev_insn_cc0_mode;
 
 
/* Previous actual insn.  0 if at first insn of basic block.  */
/* Previous actual insn.  0 if at first insn of basic block.  */
 
 
static rtx prev_insn;
static rtx prev_insn;
#endif
#endif
 
 
/* Insn being scanned.  */
/* Insn being scanned.  */
 
 
static rtx this_insn;
static rtx this_insn;
 
 
/* Index by register number, gives the number of the next (or
/* Index by register number, gives the number of the next (or
   previous) register in the chain of registers sharing the same
   previous) register in the chain of registers sharing the same
   value.
   value.
 
 
   Or -1 if this register is at the end of the chain.
   Or -1 if this register is at the end of the chain.
 
 
   If REG_QTY (N) == -N - 1, reg_eqv_table[N].next is undefined.  */
   If REG_QTY (N) == -N - 1, reg_eqv_table[N].next is undefined.  */
 
 
/* Per-register equivalence chain.  */
/* Per-register equivalence chain.  */
struct reg_eqv_elem
struct reg_eqv_elem
{
{
  int next, prev;
  int next, prev;
};
};
 
 
/* The table of all register equivalence chains.  */
/* The table of all register equivalence chains.  */
static struct reg_eqv_elem *reg_eqv_table;
static struct reg_eqv_elem *reg_eqv_table;
 
 
struct cse_reg_info
struct cse_reg_info
{
{
  /* The timestamp at which this register is initialized.  */
  /* The timestamp at which this register is initialized.  */
  unsigned int timestamp;
  unsigned int timestamp;
 
 
  /* The quantity number of the register's current contents.  */
  /* The quantity number of the register's current contents.  */
  int reg_qty;
  int reg_qty;
 
 
  /* The number of times the register has been altered in the current
  /* The number of times the register has been altered in the current
     basic block.  */
     basic block.  */
  int reg_tick;
  int reg_tick;
 
 
  /* The REG_TICK value at which rtx's containing this register are
  /* The REG_TICK value at which rtx's containing this register are
     valid in the hash table.  If this does not equal the current
     valid in the hash table.  If this does not equal the current
     reg_tick value, such expressions existing in the hash table are
     reg_tick value, such expressions existing in the hash table are
     invalid.  */
     invalid.  */
  int reg_in_table;
  int reg_in_table;
 
 
  /* The SUBREG that was set when REG_TICK was last incremented.  Set
  /* The SUBREG that was set when REG_TICK was last incremented.  Set
     to -1 if the last store was to the whole register, not a subreg.  */
     to -1 if the last store was to the whole register, not a subreg.  */
  unsigned int subreg_ticked;
  unsigned int subreg_ticked;
};
};
 
 
/* A table of cse_reg_info indexed by register numbers.  */
/* A table of cse_reg_info indexed by register numbers.  */
static struct cse_reg_info *cse_reg_info_table;
static struct cse_reg_info *cse_reg_info_table;
 
 
/* The size of the above table.  */
/* The size of the above table.  */
static unsigned int cse_reg_info_table_size;
static unsigned int cse_reg_info_table_size;
 
 
/* The index of the first entry that has not been initialized.  */
/* The index of the first entry that has not been initialized.  */
static unsigned int cse_reg_info_table_first_uninitialized;
static unsigned int cse_reg_info_table_first_uninitialized;
 
 
/* The timestamp at the beginning of the current run of
/* The timestamp at the beginning of the current run of
   cse_basic_block.  We increment this variable at the beginning of
   cse_basic_block.  We increment this variable at the beginning of
   the current run of cse_basic_block.  The timestamp field of a
   the current run of cse_basic_block.  The timestamp field of a
   cse_reg_info entry matches the value of this variable if and only
   cse_reg_info entry matches the value of this variable if and only
   if the entry has been initialized during the current run of
   if the entry has been initialized during the current run of
   cse_basic_block.  */
   cse_basic_block.  */
static unsigned int cse_reg_info_timestamp;
static unsigned int cse_reg_info_timestamp;
 
 
/* A HARD_REG_SET containing all the hard registers for which there is
/* A HARD_REG_SET containing all the hard registers for which there is
   currently a REG expression in the hash table.  Note the difference
   currently a REG expression in the hash table.  Note the difference
   from the above variables, which indicate if the REG is mentioned in some
   from the above variables, which indicate if the REG is mentioned in some
   expression in the table.  */
   expression in the table.  */
 
 
static HARD_REG_SET hard_regs_in_table;
static HARD_REG_SET hard_regs_in_table;
 
 
/* CUID of insn that starts the basic block currently being cse-processed.  */
/* CUID of insn that starts the basic block currently being cse-processed.  */
 
 
static int cse_basic_block_start;
static int cse_basic_block_start;
 
 
/* CUID of insn that ends the basic block currently being cse-processed.  */
/* CUID of insn that ends the basic block currently being cse-processed.  */
 
 
static int cse_basic_block_end;
static int cse_basic_block_end;
 
 
/* Vector mapping INSN_UIDs to cuids.
/* Vector mapping INSN_UIDs to cuids.
   The cuids are like uids but increase monotonically always.
   The cuids are like uids but increase monotonically always.
   We use them to see whether a reg is used outside a given basic block.  */
   We use them to see whether a reg is used outside a given basic block.  */
 
 
static int *uid_cuid;
static int *uid_cuid;
 
 
/* Highest UID in UID_CUID.  */
/* Highest UID in UID_CUID.  */
static int max_uid;
static int max_uid;
 
 
/* Get the cuid of an insn.  */
/* Get the cuid of an insn.  */
 
 
#define INSN_CUID(INSN) (uid_cuid[INSN_UID (INSN)])
#define INSN_CUID(INSN) (uid_cuid[INSN_UID (INSN)])
 
 
/* Nonzero if this pass has made changes, and therefore it's
/* Nonzero if this pass has made changes, and therefore it's
   worthwhile to run the garbage collector.  */
   worthwhile to run the garbage collector.  */
 
 
static int cse_altered;
static int cse_altered;
 
 
/* Nonzero if cse has altered conditional jump insns
/* Nonzero if cse has altered conditional jump insns
   in such a way that jump optimization should be redone.  */
   in such a way that jump optimization should be redone.  */
 
 
static int cse_jumps_altered;
static int cse_jumps_altered;
 
 
/* Nonzero if we put a LABEL_REF into the hash table for an INSN without a
/* Nonzero if we put a LABEL_REF into the hash table for an INSN without a
   REG_LABEL, we have to rerun jump after CSE to put in the note.  */
   REG_LABEL, we have to rerun jump after CSE to put in the note.  */
static int recorded_label_ref;
static int recorded_label_ref;
 
 
/* canon_hash stores 1 in do_not_record
/* canon_hash stores 1 in do_not_record
   if it notices a reference to CC0, PC, or some other volatile
   if it notices a reference to CC0, PC, or some other volatile
   subexpression.  */
   subexpression.  */
 
 
static int do_not_record;
static int do_not_record;
 
 
/* canon_hash stores 1 in hash_arg_in_memory
/* canon_hash stores 1 in hash_arg_in_memory
   if it notices a reference to memory within the expression being hashed.  */
   if it notices a reference to memory within the expression being hashed.  */
 
 
static int hash_arg_in_memory;
static int hash_arg_in_memory;
 
 
/* The hash table contains buckets which are chains of `struct table_elt's,
/* The hash table contains buckets which are chains of `struct table_elt's,
   each recording one expression's information.
   each recording one expression's information.
   That expression is in the `exp' field.
   That expression is in the `exp' field.
 
 
   The canon_exp field contains a canonical (from the point of view of
   The canon_exp field contains a canonical (from the point of view of
   alias analysis) version of the `exp' field.
   alias analysis) version of the `exp' field.
 
 
   Those elements with the same hash code are chained in both directions
   Those elements with the same hash code are chained in both directions
   through the `next_same_hash' and `prev_same_hash' fields.
   through the `next_same_hash' and `prev_same_hash' fields.
 
 
   Each set of expressions with equivalent values
   Each set of expressions with equivalent values
   are on a two-way chain through the `next_same_value'
   are on a two-way chain through the `next_same_value'
   and `prev_same_value' fields, and all point with
   and `prev_same_value' fields, and all point with
   the `first_same_value' field at the first element in
   the `first_same_value' field at the first element in
   that chain.  The chain is in order of increasing cost.
   that chain.  The chain is in order of increasing cost.
   Each element's cost value is in its `cost' field.
   Each element's cost value is in its `cost' field.
 
 
   The `in_memory' field is nonzero for elements that
   The `in_memory' field is nonzero for elements that
   involve any reference to memory.  These elements are removed
   involve any reference to memory.  These elements are removed
   whenever a write is done to an unidentified location in memory.
   whenever a write is done to an unidentified location in memory.
   To be safe, we assume that a memory address is unidentified unless
   To be safe, we assume that a memory address is unidentified unless
   the address is either a symbol constant or a constant plus
   the address is either a symbol constant or a constant plus
   the frame pointer or argument pointer.
   the frame pointer or argument pointer.
 
 
   The `related_value' field is used to connect related expressions
   The `related_value' field is used to connect related expressions
   (that differ by adding an integer).
   (that differ by adding an integer).
   The related expressions are chained in a circular fashion.
   The related expressions are chained in a circular fashion.
   `related_value' is zero for expressions for which this
   `related_value' is zero for expressions for which this
   chain is not useful.
   chain is not useful.
 
 
   The `cost' field stores the cost of this element's expression.
   The `cost' field stores the cost of this element's expression.
   The `regcost' field stores the value returned by approx_reg_cost for
   The `regcost' field stores the value returned by approx_reg_cost for
   this element's expression.
   this element's expression.
 
 
   The `is_const' flag is set if the element is a constant (including
   The `is_const' flag is set if the element is a constant (including
   a fixed address).
   a fixed address).
 
 
   The `flag' field is used as a temporary during some search routines.
   The `flag' field is used as a temporary during some search routines.
 
 
   The `mode' field is usually the same as GET_MODE (`exp'), but
   The `mode' field is usually the same as GET_MODE (`exp'), but
   if `exp' is a CONST_INT and has no machine mode then the `mode'
   if `exp' is a CONST_INT and has no machine mode then the `mode'
   field is the mode it was being used as.  Each constant is
   field is the mode it was being used as.  Each constant is
   recorded separately for each mode it is used with.  */
   recorded separately for each mode it is used with.  */
 
 
struct table_elt
struct table_elt
{
{
  rtx exp;
  rtx exp;
  rtx canon_exp;
  rtx canon_exp;
  struct table_elt *next_same_hash;
  struct table_elt *next_same_hash;
  struct table_elt *prev_same_hash;
  struct table_elt *prev_same_hash;
  struct table_elt *next_same_value;
  struct table_elt *next_same_value;
  struct table_elt *prev_same_value;
  struct table_elt *prev_same_value;
  struct table_elt *first_same_value;
  struct table_elt *first_same_value;
  struct table_elt *related_value;
  struct table_elt *related_value;
  int cost;
  int cost;
  int regcost;
  int regcost;
  /* The size of this field should match the size
  /* The size of this field should match the size
     of the mode field of struct rtx_def (see rtl.h).  */
     of the mode field of struct rtx_def (see rtl.h).  */
  ENUM_BITFIELD(machine_mode) mode : 8;
  ENUM_BITFIELD(machine_mode) mode : 8;
  char in_memory;
  char in_memory;
  char is_const;
  char is_const;
  char flag;
  char flag;
};
};
 
 
/* We don't want a lot of buckets, because we rarely have very many
/* We don't want a lot of buckets, because we rarely have very many
   things stored in the hash table, and a lot of buckets slows
   things stored in the hash table, and a lot of buckets slows
   down a lot of loops that happen frequently.  */
   down a lot of loops that happen frequently.  */
#define HASH_SHIFT      5
#define HASH_SHIFT      5
#define HASH_SIZE       (1 << HASH_SHIFT)
#define HASH_SIZE       (1 << HASH_SHIFT)
#define HASH_MASK       (HASH_SIZE - 1)
#define HASH_MASK       (HASH_SIZE - 1)
 
 
/* Compute hash code of X in mode M.  Special-case case where X is a pseudo
/* Compute hash code of X in mode M.  Special-case case where X is a pseudo
   register (hard registers may require `do_not_record' to be set).  */
   register (hard registers may require `do_not_record' to be set).  */
 
 
#define HASH(X, M)      \
#define HASH(X, M)      \
 ((REG_P (X) && REGNO (X) >= FIRST_PSEUDO_REGISTER      \
 ((REG_P (X) && REGNO (X) >= FIRST_PSEUDO_REGISTER      \
  ? (((unsigned) REG << 7) + (unsigned) REG_QTY (REGNO (X)))    \
  ? (((unsigned) REG << 7) + (unsigned) REG_QTY (REGNO (X)))    \
  : canon_hash (X, M)) & HASH_MASK)
  : canon_hash (X, M)) & HASH_MASK)
 
 
/* Like HASH, but without side-effects.  */
/* Like HASH, but without side-effects.  */
#define SAFE_HASH(X, M) \
#define SAFE_HASH(X, M) \
 ((REG_P (X) && REGNO (X) >= FIRST_PSEUDO_REGISTER      \
 ((REG_P (X) && REGNO (X) >= FIRST_PSEUDO_REGISTER      \
  ? (((unsigned) REG << 7) + (unsigned) REG_QTY (REGNO (X)))    \
  ? (((unsigned) REG << 7) + (unsigned) REG_QTY (REGNO (X)))    \
  : safe_hash (X, M)) & HASH_MASK)
  : safe_hash (X, M)) & HASH_MASK)
 
 
/* Determine whether register number N is considered a fixed register for the
/* Determine whether register number N is considered a fixed register for the
   purpose of approximating register costs.
   purpose of approximating register costs.
   It is desirable to replace other regs with fixed regs, to reduce need for
   It is desirable to replace other regs with fixed regs, to reduce need for
   non-fixed hard regs.
   non-fixed hard regs.
   A reg wins if it is either the frame pointer or designated as fixed.  */
   A reg wins if it is either the frame pointer or designated as fixed.  */
#define FIXED_REGNO_P(N)  \
#define FIXED_REGNO_P(N)  \
  ((N) == FRAME_POINTER_REGNUM || (N) == HARD_FRAME_POINTER_REGNUM \
  ((N) == FRAME_POINTER_REGNUM || (N) == HARD_FRAME_POINTER_REGNUM \
   || fixed_regs[N] || global_regs[N])
   || fixed_regs[N] || global_regs[N])
 
 
/* Compute cost of X, as stored in the `cost' field of a table_elt.  Fixed
/* Compute cost of X, as stored in the `cost' field of a table_elt.  Fixed
   hard registers and pointers into the frame are the cheapest with a cost
   hard registers and pointers into the frame are the cheapest with a cost
   of 0.  Next come pseudos with a cost of one and other hard registers with
   of 0.  Next come pseudos with a cost of one and other hard registers with
   a cost of 2.  Aside from these special cases, call `rtx_cost'.  */
   a cost of 2.  Aside from these special cases, call `rtx_cost'.  */
 
 
#define CHEAP_REGNO(N)                                                  \
#define CHEAP_REGNO(N)                                                  \
  (REGNO_PTR_FRAME_P(N)                                                 \
  (REGNO_PTR_FRAME_P(N)                                                 \
   || (HARD_REGISTER_NUM_P (N)                                          \
   || (HARD_REGISTER_NUM_P (N)                                          \
       && FIXED_REGNO_P (N) && REGNO_REG_CLASS (N) != NO_REGS))
       && FIXED_REGNO_P (N) && REGNO_REG_CLASS (N) != NO_REGS))
 
 
#define COST(X) (REG_P (X) ? 0 : notreg_cost (X, SET))
#define COST(X) (REG_P (X) ? 0 : notreg_cost (X, SET))
#define COST_IN(X,OUTER) (REG_P (X) ? 0 : notreg_cost (X, OUTER))
#define COST_IN(X,OUTER) (REG_P (X) ? 0 : notreg_cost (X, OUTER))
 
 
/* Get the number of times this register has been updated in this
/* Get the number of times this register has been updated in this
   basic block.  */
   basic block.  */
 
 
#define REG_TICK(N) (get_cse_reg_info (N)->reg_tick)
#define REG_TICK(N) (get_cse_reg_info (N)->reg_tick)
 
 
/* Get the point at which REG was recorded in the table.  */
/* Get the point at which REG was recorded in the table.  */
 
 
#define REG_IN_TABLE(N) (get_cse_reg_info (N)->reg_in_table)
#define REG_IN_TABLE(N) (get_cse_reg_info (N)->reg_in_table)
 
 
/* Get the SUBREG set at the last increment to REG_TICK (-1 if not a
/* Get the SUBREG set at the last increment to REG_TICK (-1 if not a
   SUBREG).  */
   SUBREG).  */
 
 
#define SUBREG_TICKED(N) (get_cse_reg_info (N)->subreg_ticked)
#define SUBREG_TICKED(N) (get_cse_reg_info (N)->subreg_ticked)
 
 
/* Get the quantity number for REG.  */
/* Get the quantity number for REG.  */
 
 
#define REG_QTY(N) (get_cse_reg_info (N)->reg_qty)
#define REG_QTY(N) (get_cse_reg_info (N)->reg_qty)
 
 
/* Determine if the quantity number for register X represents a valid index
/* Determine if the quantity number for register X represents a valid index
   into the qty_table.  */
   into the qty_table.  */
 
 
#define REGNO_QTY_VALID_P(N) (REG_QTY (N) >= 0)
#define REGNO_QTY_VALID_P(N) (REG_QTY (N) >= 0)
 
 
static struct table_elt *table[HASH_SIZE];
static struct table_elt *table[HASH_SIZE];
 
 
/* Number of elements in the hash table.  */
/* Number of elements in the hash table.  */
 
 
static unsigned int table_size;
static unsigned int table_size;
 
 
/* Chain of `struct table_elt's made so far for this function
/* Chain of `struct table_elt's made so far for this function
   but currently removed from the table.  */
   but currently removed from the table.  */
 
 
static struct table_elt *free_element_chain;
static struct table_elt *free_element_chain;
 
 
/* Set to the cost of a constant pool reference if one was found for a
/* Set to the cost of a constant pool reference if one was found for a
   symbolic constant.  If this was found, it means we should try to
   symbolic constant.  If this was found, it means we should try to
   convert constants into constant pool entries if they don't fit in
   convert constants into constant pool entries if they don't fit in
   the insn.  */
   the insn.  */
 
 
static int constant_pool_entries_cost;
static int constant_pool_entries_cost;
static int constant_pool_entries_regcost;
static int constant_pool_entries_regcost;
 
 
/* This data describes a block that will be processed by cse_basic_block.  */
/* This data describes a block that will be processed by cse_basic_block.  */
 
 
struct cse_basic_block_data
struct cse_basic_block_data
{
{
  /* Lowest CUID value of insns in block.  */
  /* Lowest CUID value of insns in block.  */
  int low_cuid;
  int low_cuid;
  /* Highest CUID value of insns in block.  */
  /* Highest CUID value of insns in block.  */
  int high_cuid;
  int high_cuid;
  /* Total number of SETs in block.  */
  /* Total number of SETs in block.  */
  int nsets;
  int nsets;
  /* Last insn in the block.  */
  /* Last insn in the block.  */
  rtx last;
  rtx last;
  /* Size of current branch path, if any.  */
  /* Size of current branch path, if any.  */
  int path_size;
  int path_size;
  /* Current branch path, indicating which branches will be taken.  */
  /* Current branch path, indicating which branches will be taken.  */
  struct branch_path
  struct branch_path
    {
    {
      /* The branch insn.  */
      /* The branch insn.  */
      rtx branch;
      rtx branch;
      /* Whether it should be taken or not.  AROUND is the same as taken
      /* Whether it should be taken or not.  AROUND is the same as taken
         except that it is used when the destination label is not preceded
         except that it is used when the destination label is not preceded
       by a BARRIER.  */
       by a BARRIER.  */
      enum taken {PATH_TAKEN, PATH_NOT_TAKEN, PATH_AROUND} status;
      enum taken {PATH_TAKEN, PATH_NOT_TAKEN, PATH_AROUND} status;
    } *path;
    } *path;
};
};
 
 
static bool fixed_base_plus_p (rtx x);
static bool fixed_base_plus_p (rtx x);
static int notreg_cost (rtx, enum rtx_code);
static int notreg_cost (rtx, enum rtx_code);
static int approx_reg_cost_1 (rtx *, void *);
static int approx_reg_cost_1 (rtx *, void *);
static int approx_reg_cost (rtx);
static int approx_reg_cost (rtx);
static int preferable (int, int, int, int);
static int preferable (int, int, int, int);
static void new_basic_block (void);
static void new_basic_block (void);
static void make_new_qty (unsigned int, enum machine_mode);
static void make_new_qty (unsigned int, enum machine_mode);
static void make_regs_eqv (unsigned int, unsigned int);
static void make_regs_eqv (unsigned int, unsigned int);
static void delete_reg_equiv (unsigned int);
static void delete_reg_equiv (unsigned int);
static int mention_regs (rtx);
static int mention_regs (rtx);
static int insert_regs (rtx, struct table_elt *, int);
static int insert_regs (rtx, struct table_elt *, int);
static void remove_from_table (struct table_elt *, unsigned);
static void remove_from_table (struct table_elt *, unsigned);
static struct table_elt *lookup (rtx, unsigned, enum machine_mode);
static struct table_elt *lookup (rtx, unsigned, enum machine_mode);
static struct table_elt *lookup_for_remove (rtx, unsigned, enum machine_mode);
static struct table_elt *lookup_for_remove (rtx, unsigned, enum machine_mode);
static rtx lookup_as_function (rtx, enum rtx_code);
static rtx lookup_as_function (rtx, enum rtx_code);
static struct table_elt *insert (rtx, struct table_elt *, unsigned,
static struct table_elt *insert (rtx, struct table_elt *, unsigned,
                                 enum machine_mode);
                                 enum machine_mode);
static void merge_equiv_classes (struct table_elt *, struct table_elt *);
static void merge_equiv_classes (struct table_elt *, struct table_elt *);
static void invalidate (rtx, enum machine_mode);
static void invalidate (rtx, enum machine_mode);
static int cse_rtx_varies_p (rtx, int);
static int cse_rtx_varies_p (rtx, int);
static void remove_invalid_refs (unsigned int);
static void remove_invalid_refs (unsigned int);
static void remove_invalid_subreg_refs (unsigned int, unsigned int,
static void remove_invalid_subreg_refs (unsigned int, unsigned int,
                                        enum machine_mode);
                                        enum machine_mode);
static void rehash_using_reg (rtx);
static void rehash_using_reg (rtx);
static void invalidate_memory (void);
static void invalidate_memory (void);
static void invalidate_for_call (void);
static void invalidate_for_call (void);
static rtx use_related_value (rtx, struct table_elt *);
static rtx use_related_value (rtx, struct table_elt *);
 
 
static inline unsigned canon_hash (rtx, enum machine_mode);
static inline unsigned canon_hash (rtx, enum machine_mode);
static inline unsigned safe_hash (rtx, enum machine_mode);
static inline unsigned safe_hash (rtx, enum machine_mode);
static unsigned hash_rtx_string (const char *);
static unsigned hash_rtx_string (const char *);
 
 
static rtx canon_reg (rtx, rtx);
static rtx canon_reg (rtx, rtx);
static void find_best_addr (rtx, rtx *, enum machine_mode);
static void find_best_addr (rtx, rtx *, enum machine_mode);
static enum rtx_code find_comparison_args (enum rtx_code, rtx *, rtx *,
static enum rtx_code find_comparison_args (enum rtx_code, rtx *, rtx *,
                                           enum machine_mode *,
                                           enum machine_mode *,
                                           enum machine_mode *);
                                           enum machine_mode *);
static rtx fold_rtx (rtx, rtx);
static rtx fold_rtx (rtx, rtx);
static rtx equiv_constant (rtx);
static rtx equiv_constant (rtx);
static void record_jump_equiv (rtx, int);
static void record_jump_equiv (rtx, int);
static void record_jump_cond (enum rtx_code, enum machine_mode, rtx, rtx,
static void record_jump_cond (enum rtx_code, enum machine_mode, rtx, rtx,
                              int);
                              int);
static void cse_insn (rtx, rtx);
static void cse_insn (rtx, rtx);
static void cse_end_of_basic_block (rtx, struct cse_basic_block_data *,
static void cse_end_of_basic_block (rtx, struct cse_basic_block_data *,
                                    int, int);
                                    int, int);
static int addr_affects_sp_p (rtx);
static int addr_affects_sp_p (rtx);
static void invalidate_from_clobbers (rtx);
static void invalidate_from_clobbers (rtx);
static rtx cse_process_notes (rtx, rtx);
static rtx cse_process_notes (rtx, rtx);
static void invalidate_skipped_set (rtx, rtx, void *);
static void invalidate_skipped_set (rtx, rtx, void *);
static void invalidate_skipped_block (rtx);
static void invalidate_skipped_block (rtx);
static rtx cse_basic_block (rtx, rtx, struct branch_path *);
static rtx cse_basic_block (rtx, rtx, struct branch_path *);
static void count_reg_usage (rtx, int *, rtx, int);
static void count_reg_usage (rtx, int *, rtx, int);
static int check_for_label_ref (rtx *, void *);
static int check_for_label_ref (rtx *, void *);
extern void dump_class (struct table_elt*);
extern void dump_class (struct table_elt*);
static void get_cse_reg_info_1 (unsigned int regno);
static void get_cse_reg_info_1 (unsigned int regno);
static struct cse_reg_info * get_cse_reg_info (unsigned int regno);
static struct cse_reg_info * get_cse_reg_info (unsigned int regno);
static int check_dependence (rtx *, void *);
static int check_dependence (rtx *, void *);
 
 
static void flush_hash_table (void);
static void flush_hash_table (void);
static bool insn_live_p (rtx, int *);
static bool insn_live_p (rtx, int *);
static bool set_live_p (rtx, rtx, int *);
static bool set_live_p (rtx, rtx, int *);
static bool dead_libcall_p (rtx, int *);
static bool dead_libcall_p (rtx, int *);
static int cse_change_cc_mode (rtx *, void *);
static int cse_change_cc_mode (rtx *, void *);
static void cse_change_cc_mode_insn (rtx, rtx);
static void cse_change_cc_mode_insn (rtx, rtx);
static void cse_change_cc_mode_insns (rtx, rtx, rtx);
static void cse_change_cc_mode_insns (rtx, rtx, rtx);
static enum machine_mode cse_cc_succs (basic_block, rtx, rtx, bool);
static enum machine_mode cse_cc_succs (basic_block, rtx, rtx, bool);


 
 
#undef RTL_HOOKS_GEN_LOWPART
#undef RTL_HOOKS_GEN_LOWPART
#define RTL_HOOKS_GEN_LOWPART           gen_lowpart_if_possible
#define RTL_HOOKS_GEN_LOWPART           gen_lowpart_if_possible
 
 
static const struct rtl_hooks cse_rtl_hooks = RTL_HOOKS_INITIALIZER;
static const struct rtl_hooks cse_rtl_hooks = RTL_HOOKS_INITIALIZER;


/* Nonzero if X has the form (PLUS frame-pointer integer).  We check for
/* Nonzero if X has the form (PLUS frame-pointer integer).  We check for
   virtual regs here because the simplify_*_operation routines are called
   virtual regs here because the simplify_*_operation routines are called
   by integrate.c, which is called before virtual register instantiation.  */
   by integrate.c, which is called before virtual register instantiation.  */
 
 
static bool
static bool
fixed_base_plus_p (rtx x)
fixed_base_plus_p (rtx x)
{
{
  switch (GET_CODE (x))
  switch (GET_CODE (x))
    {
    {
    case REG:
    case REG:
      if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx)
      if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx)
        return true;
        return true;
      if (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM])
      if (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM])
        return true;
        return true;
      if (REGNO (x) >= FIRST_VIRTUAL_REGISTER
      if (REGNO (x) >= FIRST_VIRTUAL_REGISTER
          && REGNO (x) <= LAST_VIRTUAL_REGISTER)
          && REGNO (x) <= LAST_VIRTUAL_REGISTER)
        return true;
        return true;
      return false;
      return false;
 
 
    case PLUS:
    case PLUS:
      if (GET_CODE (XEXP (x, 1)) != CONST_INT)
      if (GET_CODE (XEXP (x, 1)) != CONST_INT)
        return false;
        return false;
      return fixed_base_plus_p (XEXP (x, 0));
      return fixed_base_plus_p (XEXP (x, 0));
 
 
    default:
    default:
      return false;
      return false;
    }
    }
}
}
 
 
/* Dump the expressions in the equivalence class indicated by CLASSP.
/* Dump the expressions in the equivalence class indicated by CLASSP.
   This function is used only for debugging.  */
   This function is used only for debugging.  */
void
void
dump_class (struct table_elt *classp)
dump_class (struct table_elt *classp)
{
{
  struct table_elt *elt;
  struct table_elt *elt;
 
 
  fprintf (stderr, "Equivalence chain for ");
  fprintf (stderr, "Equivalence chain for ");
  print_rtl (stderr, classp->exp);
  print_rtl (stderr, classp->exp);
  fprintf (stderr, ": \n");
  fprintf (stderr, ": \n");
 
 
  for (elt = classp->first_same_value; elt; elt = elt->next_same_value)
  for (elt = classp->first_same_value; elt; elt = elt->next_same_value)
    {
    {
      print_rtl (stderr, elt->exp);
      print_rtl (stderr, elt->exp);
      fprintf (stderr, "\n");
      fprintf (stderr, "\n");
    }
    }
}
}
 
 
/* Subroutine of approx_reg_cost; called through for_each_rtx.  */
/* Subroutine of approx_reg_cost; called through for_each_rtx.  */
 
 
static int
static int
approx_reg_cost_1 (rtx *xp, void *data)
approx_reg_cost_1 (rtx *xp, void *data)
{
{
  rtx x = *xp;
  rtx x = *xp;
  int *cost_p = data;
  int *cost_p = data;
 
 
  if (x && REG_P (x))
  if (x && REG_P (x))
    {
    {
      unsigned int regno = REGNO (x);
      unsigned int regno = REGNO (x);
 
 
      if (! CHEAP_REGNO (regno))
      if (! CHEAP_REGNO (regno))
        {
        {
          if (regno < FIRST_PSEUDO_REGISTER)
          if (regno < FIRST_PSEUDO_REGISTER)
            {
            {
              if (SMALL_REGISTER_CLASSES)
              if (SMALL_REGISTER_CLASSES)
                return 1;
                return 1;
              *cost_p += 2;
              *cost_p += 2;
            }
            }
          else
          else
            *cost_p += 1;
            *cost_p += 1;
        }
        }
    }
    }
 
 
  return 0;
  return 0;
}
}
 
 
/* Return an estimate of the cost of the registers used in an rtx.
/* Return an estimate of the cost of the registers used in an rtx.
   This is mostly the number of different REG expressions in the rtx;
   This is mostly the number of different REG expressions in the rtx;
   however for some exceptions like fixed registers we use a cost of
   however for some exceptions like fixed registers we use a cost of
   0.  If any other hard register reference occurs, return MAX_COST.  */
   0.  If any other hard register reference occurs, return MAX_COST.  */
 
 
static int
static int
approx_reg_cost (rtx x)
approx_reg_cost (rtx x)
{
{
  int cost = 0;
  int cost = 0;
 
 
  if (for_each_rtx (&x, approx_reg_cost_1, (void *) &cost))
  if (for_each_rtx (&x, approx_reg_cost_1, (void *) &cost))
    return MAX_COST;
    return MAX_COST;
 
 
  return cost;
  return cost;
}
}
 
 
/* Returns a canonical version of X for the address, from the point of view,
/* Returns a canonical version of X for the address, from the point of view,
   that all multiplications are represented as MULT instead of the multiply
   that all multiplications are represented as MULT instead of the multiply
   by a power of 2 being represented as ASHIFT.  */
   by a power of 2 being represented as ASHIFT.  */
 
 
static rtx
static rtx
canon_for_address (rtx x)
canon_for_address (rtx x)
{
{
  enum rtx_code code;
  enum rtx_code code;
  enum machine_mode mode;
  enum machine_mode mode;
  rtx new = 0;
  rtx new = 0;
  int i;
  int i;
  const char *fmt;
  const char *fmt;
 
 
  if (!x)
  if (!x)
    return x;
    return x;
 
 
  code = GET_CODE (x);
  code = GET_CODE (x);
  mode = GET_MODE (x);
  mode = GET_MODE (x);
 
 
  switch (code)
  switch (code)
    {
    {
    case ASHIFT:
    case ASHIFT:
      if (GET_CODE (XEXP (x, 1)) == CONST_INT
      if (GET_CODE (XEXP (x, 1)) == CONST_INT
          && INTVAL (XEXP (x, 1)) < GET_MODE_BITSIZE (mode)
          && INTVAL (XEXP (x, 1)) < GET_MODE_BITSIZE (mode)
          && INTVAL (XEXP (x, 1)) >= 0)
          && INTVAL (XEXP (x, 1)) >= 0)
        {
        {
          new = canon_for_address (XEXP (x, 0));
          new = canon_for_address (XEXP (x, 0));
          new = gen_rtx_MULT (mode, new,
          new = gen_rtx_MULT (mode, new,
                              gen_int_mode ((HOST_WIDE_INT) 1
                              gen_int_mode ((HOST_WIDE_INT) 1
                                            << INTVAL (XEXP (x, 1)),
                                            << INTVAL (XEXP (x, 1)),
                                            mode));
                                            mode));
        }
        }
      break;
      break;
    default:
    default:
      break;
      break;
 
 
    }
    }
  if (new)
  if (new)
    return new;
    return new;
 
 
  /* Now recursively process each operand of this operation.  */
  /* Now recursively process each operand of this operation.  */
  fmt = GET_RTX_FORMAT (code);
  fmt = GET_RTX_FORMAT (code);
  for (i = 0; i < GET_RTX_LENGTH (code); i++)
  for (i = 0; i < GET_RTX_LENGTH (code); i++)
    if (fmt[i] == 'e')
    if (fmt[i] == 'e')
      {
      {
        new = canon_for_address (XEXP (x, i));
        new = canon_for_address (XEXP (x, i));
        XEXP (x, i) = new;
        XEXP (x, i) = new;
      }
      }
  return x;
  return x;
}
}
 
 
/* Return a negative value if an rtx A, whose costs are given by COST_A
/* Return a negative value if an rtx A, whose costs are given by COST_A
   and REGCOST_A, is more desirable than an rtx B.
   and REGCOST_A, is more desirable than an rtx B.
   Return a positive value if A is less desirable, or 0 if the two are
   Return a positive value if A is less desirable, or 0 if the two are
   equally good.  */
   equally good.  */
static int
static int
preferable (int cost_a, int regcost_a, int cost_b, int regcost_b)
preferable (int cost_a, int regcost_a, int cost_b, int regcost_b)
{
{
  /* First, get rid of cases involving expressions that are entirely
  /* First, get rid of cases involving expressions that are entirely
     unwanted.  */
     unwanted.  */
  if (cost_a != cost_b)
  if (cost_a != cost_b)
    {
    {
      if (cost_a == MAX_COST)
      if (cost_a == MAX_COST)
        return 1;
        return 1;
      if (cost_b == MAX_COST)
      if (cost_b == MAX_COST)
        return -1;
        return -1;
    }
    }
 
 
  /* Avoid extending lifetimes of hardregs.  */
  /* Avoid extending lifetimes of hardregs.  */
  if (regcost_a != regcost_b)
  if (regcost_a != regcost_b)
    {
    {
      if (regcost_a == MAX_COST)
      if (regcost_a == MAX_COST)
        return 1;
        return 1;
      if (regcost_b == MAX_COST)
      if (regcost_b == MAX_COST)
        return -1;
        return -1;
    }
    }
 
 
  /* Normal operation costs take precedence.  */
  /* Normal operation costs take precedence.  */
  if (cost_a != cost_b)
  if (cost_a != cost_b)
    return cost_a - cost_b;
    return cost_a - cost_b;
  /* Only if these are identical consider effects on register pressure.  */
  /* Only if these are identical consider effects on register pressure.  */
  if (regcost_a != regcost_b)
  if (regcost_a != regcost_b)
    return regcost_a - regcost_b;
    return regcost_a - regcost_b;
  return 0;
  return 0;
}
}
 
 
/* Internal function, to compute cost when X is not a register; called
/* Internal function, to compute cost when X is not a register; called
   from COST macro to keep it simple.  */
   from COST macro to keep it simple.  */
 
 
static int
static int
notreg_cost (rtx x, enum rtx_code outer)
notreg_cost (rtx x, enum rtx_code outer)
{
{
  return ((GET_CODE (x) == SUBREG
  return ((GET_CODE (x) == SUBREG
           && REG_P (SUBREG_REG (x))
           && REG_P (SUBREG_REG (x))
           && GET_MODE_CLASS (GET_MODE (x)) == MODE_INT
           && GET_MODE_CLASS (GET_MODE (x)) == MODE_INT
           && GET_MODE_CLASS (GET_MODE (SUBREG_REG (x))) == MODE_INT
           && GET_MODE_CLASS (GET_MODE (SUBREG_REG (x))) == MODE_INT
           && (GET_MODE_SIZE (GET_MODE (x))
           && (GET_MODE_SIZE (GET_MODE (x))
               < GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
               < GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
           && subreg_lowpart_p (x)
           && subreg_lowpart_p (x)
           && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (GET_MODE (x)),
           && TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (GET_MODE (x)),
                                     GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (x)))))
                                     GET_MODE_BITSIZE (GET_MODE (SUBREG_REG (x)))))
          ? 0
          ? 0
          : rtx_cost (x, outer) * 2);
          : rtx_cost (x, outer) * 2);
}
}
 
 


/* Initialize CSE_REG_INFO_TABLE.  */
/* Initialize CSE_REG_INFO_TABLE.  */
 
 
static void
static void
init_cse_reg_info (unsigned int nregs)
init_cse_reg_info (unsigned int nregs)
{
{
  /* Do we need to grow the table?  */
  /* Do we need to grow the table?  */
  if (nregs > cse_reg_info_table_size)
  if (nregs > cse_reg_info_table_size)
    {
    {
      unsigned int new_size;
      unsigned int new_size;
 
 
      if (cse_reg_info_table_size < 2048)
      if (cse_reg_info_table_size < 2048)
        {
        {
          /* Compute a new size that is a power of 2 and no smaller
          /* Compute a new size that is a power of 2 and no smaller
             than the large of NREGS and 64.  */
             than the large of NREGS and 64.  */
          new_size = (cse_reg_info_table_size
          new_size = (cse_reg_info_table_size
                      ? cse_reg_info_table_size : 64);
                      ? cse_reg_info_table_size : 64);
 
 
          while (new_size < nregs)
          while (new_size < nregs)
            new_size *= 2;
            new_size *= 2;
        }
        }
      else
      else
        {
        {
          /* If we need a big table, allocate just enough to hold
          /* If we need a big table, allocate just enough to hold
             NREGS registers.  */
             NREGS registers.  */
          new_size = nregs;
          new_size = nregs;
        }
        }
 
 
      /* Reallocate the table with NEW_SIZE entries.  */
      /* Reallocate the table with NEW_SIZE entries.  */
      if (cse_reg_info_table)
      if (cse_reg_info_table)
        free (cse_reg_info_table);
        free (cse_reg_info_table);
      cse_reg_info_table = XNEWVEC (struct cse_reg_info, new_size);
      cse_reg_info_table = XNEWVEC (struct cse_reg_info, new_size);
      cse_reg_info_table_size = new_size;
      cse_reg_info_table_size = new_size;
      cse_reg_info_table_first_uninitialized = 0;
      cse_reg_info_table_first_uninitialized = 0;
    }
    }
 
 
  /* Do we have all of the first NREGS entries initialized?  */
  /* Do we have all of the first NREGS entries initialized?  */
  if (cse_reg_info_table_first_uninitialized < nregs)
  if (cse_reg_info_table_first_uninitialized < nregs)
    {
    {
      unsigned int old_timestamp = cse_reg_info_timestamp - 1;
      unsigned int old_timestamp = cse_reg_info_timestamp - 1;
      unsigned int i;
      unsigned int i;
 
 
      /* Put the old timestamp on newly allocated entries so that they
      /* Put the old timestamp on newly allocated entries so that they
         will all be considered out of date.  We do not touch those
         will all be considered out of date.  We do not touch those
         entries beyond the first NREGS entries to be nice to the
         entries beyond the first NREGS entries to be nice to the
         virtual memory.  */
         virtual memory.  */
      for (i = cse_reg_info_table_first_uninitialized; i < nregs; i++)
      for (i = cse_reg_info_table_first_uninitialized; i < nregs; i++)
        cse_reg_info_table[i].timestamp = old_timestamp;
        cse_reg_info_table[i].timestamp = old_timestamp;
 
 
      cse_reg_info_table_first_uninitialized = nregs;
      cse_reg_info_table_first_uninitialized = nregs;
    }
    }
}
}
 
 
/* Given REGNO, initialize the cse_reg_info entry for REGNO.  */
/* Given REGNO, initialize the cse_reg_info entry for REGNO.  */
 
 
static void
static void
get_cse_reg_info_1 (unsigned int regno)
get_cse_reg_info_1 (unsigned int regno)
{
{
  /* Set TIMESTAMP field to CSE_REG_INFO_TIMESTAMP so that this
  /* Set TIMESTAMP field to CSE_REG_INFO_TIMESTAMP so that this
     entry will be considered to have been initialized.  */
     entry will be considered to have been initialized.  */
  cse_reg_info_table[regno].timestamp = cse_reg_info_timestamp;
  cse_reg_info_table[regno].timestamp = cse_reg_info_timestamp;
 
 
  /* Initialize the rest of the entry.  */
  /* Initialize the rest of the entry.  */
  cse_reg_info_table[regno].reg_tick = 1;
  cse_reg_info_table[regno].reg_tick = 1;
  cse_reg_info_table[regno].reg_in_table = -1;
  cse_reg_info_table[regno].reg_in_table = -1;
  cse_reg_info_table[regno].subreg_ticked = -1;
  cse_reg_info_table[regno].subreg_ticked = -1;
  cse_reg_info_table[regno].reg_qty = -regno - 1;
  cse_reg_info_table[regno].reg_qty = -regno - 1;
}
}
 
 
/* Find a cse_reg_info entry for REGNO.  */
/* Find a cse_reg_info entry for REGNO.  */
 
 
static inline struct cse_reg_info *
static inline struct cse_reg_info *
get_cse_reg_info (unsigned int regno)
get_cse_reg_info (unsigned int regno)
{
{
  struct cse_reg_info *p = &cse_reg_info_table[regno];
  struct cse_reg_info *p = &cse_reg_info_table[regno];
 
 
  /* If this entry has not been initialized, go ahead and initialize
  /* If this entry has not been initialized, go ahead and initialize
     it.  */
     it.  */
  if (p->timestamp != cse_reg_info_timestamp)
  if (p->timestamp != cse_reg_info_timestamp)
    get_cse_reg_info_1 (regno);
    get_cse_reg_info_1 (regno);
 
 
  return p;
  return p;
}
}
 
 
/* Clear the hash table and initialize each register with its own quantity,
/* Clear the hash table and initialize each register with its own quantity,
   for a new basic block.  */
   for a new basic block.  */
 
 
static void
static void
new_basic_block (void)
new_basic_block (void)
{
{
  int i;
  int i;
 
 
  next_qty = 0;
  next_qty = 0;
 
 
  /* Invalidate cse_reg_info_table.  */
  /* Invalidate cse_reg_info_table.  */
  cse_reg_info_timestamp++;
  cse_reg_info_timestamp++;
 
 
  /* Clear out hash table state for this pass.  */
  /* Clear out hash table state for this pass.  */
  CLEAR_HARD_REG_SET (hard_regs_in_table);
  CLEAR_HARD_REG_SET (hard_regs_in_table);
 
 
  /* The per-quantity values used to be initialized here, but it is
  /* The per-quantity values used to be initialized here, but it is
     much faster to initialize each as it is made in `make_new_qty'.  */
     much faster to initialize each as it is made in `make_new_qty'.  */
 
 
  for (i = 0; i < HASH_SIZE; i++)
  for (i = 0; i < HASH_SIZE; i++)
    {
    {
      struct table_elt *first;
      struct table_elt *first;
 
 
      first = table[i];
      first = table[i];
      if (first != NULL)
      if (first != NULL)
        {
        {
          struct table_elt *last = first;
          struct table_elt *last = first;
 
 
          table[i] = NULL;
          table[i] = NULL;
 
 
          while (last->next_same_hash != NULL)
          while (last->next_same_hash != NULL)
            last = last->next_same_hash;
            last = last->next_same_hash;
 
 
          /* Now relink this hash entire chain into
          /* Now relink this hash entire chain into
             the free element list.  */
             the free element list.  */
 
 
          last->next_same_hash = free_element_chain;
          last->next_same_hash = free_element_chain;
          free_element_chain = first;
          free_element_chain = first;
        }
        }
    }
    }
 
 
  table_size = 0;
  table_size = 0;
 
 
#ifdef HAVE_cc0
#ifdef HAVE_cc0
  prev_insn = 0;
  prev_insn = 0;
  prev_insn_cc0 = 0;
  prev_insn_cc0 = 0;
#endif
#endif
}
}
 
 
/* Say that register REG contains a quantity in mode MODE not in any
/* Say that register REG contains a quantity in mode MODE not in any
   register before and initialize that quantity.  */
   register before and initialize that quantity.  */
 
 
static void
static void
make_new_qty (unsigned int reg, enum machine_mode mode)
make_new_qty (unsigned int reg, enum machine_mode mode)
{
{
  int q;
  int q;
  struct qty_table_elem *ent;
  struct qty_table_elem *ent;
  struct reg_eqv_elem *eqv;
  struct reg_eqv_elem *eqv;
 
 
  gcc_assert (next_qty < max_qty);
  gcc_assert (next_qty < max_qty);
 
 
  q = REG_QTY (reg) = next_qty++;
  q = REG_QTY (reg) = next_qty++;
  ent = &qty_table[q];
  ent = &qty_table[q];
  ent->first_reg = reg;
  ent->first_reg = reg;
  ent->last_reg = reg;
  ent->last_reg = reg;
  ent->mode = mode;
  ent->mode = mode;
  ent->const_rtx = ent->const_insn = NULL_RTX;
  ent->const_rtx = ent->const_insn = NULL_RTX;
  ent->comparison_code = UNKNOWN;
  ent->comparison_code = UNKNOWN;
 
 
  eqv = &reg_eqv_table[reg];
  eqv = &reg_eqv_table[reg];
  eqv->next = eqv->prev = -1;
  eqv->next = eqv->prev = -1;
}
}
 
 
/* Make reg NEW equivalent to reg OLD.
/* Make reg NEW equivalent to reg OLD.
   OLD is not changing; NEW is.  */
   OLD is not changing; NEW is.  */
 
 
static void
static void
make_regs_eqv (unsigned int new, unsigned int old)
make_regs_eqv (unsigned int new, unsigned int old)
{
{
  unsigned int lastr, firstr;
  unsigned int lastr, firstr;
  int q = REG_QTY (old);
  int q = REG_QTY (old);
  struct qty_table_elem *ent;
  struct qty_table_elem *ent;
 
 
  ent = &qty_table[q];
  ent = &qty_table[q];
 
 
  /* Nothing should become eqv until it has a "non-invalid" qty number.  */
  /* Nothing should become eqv until it has a "non-invalid" qty number.  */
  gcc_assert (REGNO_QTY_VALID_P (old));
  gcc_assert (REGNO_QTY_VALID_P (old));
 
 
  REG_QTY (new) = q;
  REG_QTY (new) = q;
  firstr = ent->first_reg;
  firstr = ent->first_reg;
  lastr = ent->last_reg;
  lastr = ent->last_reg;
 
 
  /* Prefer fixed hard registers to anything.  Prefer pseudo regs to other
  /* Prefer fixed hard registers to anything.  Prefer pseudo regs to other
     hard regs.  Among pseudos, if NEW will live longer than any other reg
     hard regs.  Among pseudos, if NEW will live longer than any other reg
     of the same qty, and that is beyond the current basic block,
     of the same qty, and that is beyond the current basic block,
     make it the new canonical replacement for this qty.  */
     make it the new canonical replacement for this qty.  */
  if (! (firstr < FIRST_PSEUDO_REGISTER && FIXED_REGNO_P (firstr))
  if (! (firstr < FIRST_PSEUDO_REGISTER && FIXED_REGNO_P (firstr))
      /* Certain fixed registers might be of the class NO_REGS.  This means
      /* Certain fixed registers might be of the class NO_REGS.  This means
         that not only can they not be allocated by the compiler, but
         that not only can they not be allocated by the compiler, but
         they cannot be used in substitutions or canonicalizations
         they cannot be used in substitutions or canonicalizations
         either.  */
         either.  */
      && (new >= FIRST_PSEUDO_REGISTER || REGNO_REG_CLASS (new) != NO_REGS)
      && (new >= FIRST_PSEUDO_REGISTER || REGNO_REG_CLASS (new) != NO_REGS)
      && ((new < FIRST_PSEUDO_REGISTER && FIXED_REGNO_P (new))
      && ((new < FIRST_PSEUDO_REGISTER && FIXED_REGNO_P (new))
          || (new >= FIRST_PSEUDO_REGISTER
          || (new >= FIRST_PSEUDO_REGISTER
              && (firstr < FIRST_PSEUDO_REGISTER
              && (firstr < FIRST_PSEUDO_REGISTER
                  || ((uid_cuid[REGNO_LAST_UID (new)] > cse_basic_block_end
                  || ((uid_cuid[REGNO_LAST_UID (new)] > cse_basic_block_end
                       || (uid_cuid[REGNO_FIRST_UID (new)]
                       || (uid_cuid[REGNO_FIRST_UID (new)]
                           < cse_basic_block_start))
                           < cse_basic_block_start))
                      && (uid_cuid[REGNO_LAST_UID (new)]
                      && (uid_cuid[REGNO_LAST_UID (new)]
                          > uid_cuid[REGNO_LAST_UID (firstr)]))))))
                          > uid_cuid[REGNO_LAST_UID (firstr)]))))))
    {
    {
      reg_eqv_table[firstr].prev = new;
      reg_eqv_table[firstr].prev = new;
      reg_eqv_table[new].next = firstr;
      reg_eqv_table[new].next = firstr;
      reg_eqv_table[new].prev = -1;
      reg_eqv_table[new].prev = -1;
      ent->first_reg = new;
      ent->first_reg = new;
    }
    }
  else
  else
    {
    {
      /* If NEW is a hard reg (known to be non-fixed), insert at end.
      /* If NEW is a hard reg (known to be non-fixed), insert at end.
         Otherwise, insert before any non-fixed hard regs that are at the
         Otherwise, insert before any non-fixed hard regs that are at the
         end.  Registers of class NO_REGS cannot be used as an
         end.  Registers of class NO_REGS cannot be used as an
         equivalent for anything.  */
         equivalent for anything.  */
      while (lastr < FIRST_PSEUDO_REGISTER && reg_eqv_table[lastr].prev >= 0
      while (lastr < FIRST_PSEUDO_REGISTER && reg_eqv_table[lastr].prev >= 0
             && (REGNO_REG_CLASS (lastr) == NO_REGS || ! FIXED_REGNO_P (lastr))
             && (REGNO_REG_CLASS (lastr) == NO_REGS || ! FIXED_REGNO_P (lastr))
             && new >= FIRST_PSEUDO_REGISTER)
             && new >= FIRST_PSEUDO_REGISTER)
        lastr = reg_eqv_table[lastr].prev;
        lastr = reg_eqv_table[lastr].prev;
      reg_eqv_table[new].next = reg_eqv_table[lastr].next;
      reg_eqv_table[new].next = reg_eqv_table[lastr].next;
      if (reg_eqv_table[lastr].next >= 0)
      if (reg_eqv_table[lastr].next >= 0)
        reg_eqv_table[reg_eqv_table[lastr].next].prev = new;
        reg_eqv_table[reg_eqv_table[lastr].next].prev = new;
      else
      else
        qty_table[q].last_reg = new;
        qty_table[q].last_reg = new;
      reg_eqv_table[lastr].next = new;
      reg_eqv_table[lastr].next = new;
      reg_eqv_table[new].prev = lastr;
      reg_eqv_table[new].prev = lastr;
    }
    }
}
}
 
 
/* Remove REG from its equivalence class.  */
/* Remove REG from its equivalence class.  */
 
 
static void
static void
delete_reg_equiv (unsigned int reg)
delete_reg_equiv (unsigned int reg)
{
{
  struct qty_table_elem *ent;
  struct qty_table_elem *ent;
  int q = REG_QTY (reg);
  int q = REG_QTY (reg);
  int p, n;
  int p, n;
 
 
  /* If invalid, do nothing.  */
  /* If invalid, do nothing.  */
  if (! REGNO_QTY_VALID_P (reg))
  if (! REGNO_QTY_VALID_P (reg))
    return;
    return;
 
 
  ent = &qty_table[q];
  ent = &qty_table[q];
 
 
  p = reg_eqv_table[reg].prev;
  p = reg_eqv_table[reg].prev;
  n = reg_eqv_table[reg].next;
  n = reg_eqv_table[reg].next;
 
 
  if (n != -1)
  if (n != -1)
    reg_eqv_table[n].prev = p;
    reg_eqv_table[n].prev = p;
  else
  else
    ent->last_reg = p;
    ent->last_reg = p;
  if (p != -1)
  if (p != -1)
    reg_eqv_table[p].next = n;
    reg_eqv_table[p].next = n;
  else
  else
    ent->first_reg = n;
    ent->first_reg = n;
 
 
  REG_QTY (reg) = -reg - 1;
  REG_QTY (reg) = -reg - 1;
}
}
 
 
/* Remove any invalid expressions from the hash table
/* Remove any invalid expressions from the hash table
   that refer to any of the registers contained in expression X.
   that refer to any of the registers contained in expression X.
 
 
   Make sure that newly inserted references to those registers
   Make sure that newly inserted references to those registers
   as subexpressions will be considered valid.
   as subexpressions will be considered valid.
 
 
   mention_regs is not called when a register itself
   mention_regs is not called when a register itself
   is being stored in the table.
   is being stored in the table.
 
 
   Return 1 if we have done something that may have changed the hash code
   Return 1 if we have done something that may have changed the hash code
   of X.  */
   of X.  */
 
 
static int
static int
mention_regs (rtx x)
mention_regs (rtx x)
{
{
  enum rtx_code code;
  enum rtx_code code;
  int i, j;
  int i, j;
  const char *fmt;
  const char *fmt;
  int changed = 0;
  int changed = 0;
 
 
  if (x == 0)
  if (x == 0)
    return 0;
    return 0;
 
 
  code = GET_CODE (x);
  code = GET_CODE (x);
  if (code == REG)
  if (code == REG)
    {
    {
      unsigned int regno = REGNO (x);
      unsigned int regno = REGNO (x);
      unsigned int endregno
      unsigned int endregno
        = regno + (regno >= FIRST_PSEUDO_REGISTER ? 1
        = regno + (regno >= FIRST_PSEUDO_REGISTER ? 1
                   : hard_regno_nregs[regno][GET_MODE (x)]);
                   : hard_regno_nregs[regno][GET_MODE (x)]);
      unsigned int i;
      unsigned int i;
 
 
      for (i = regno; i < endregno; i++)
      for (i = regno; i < endregno; i++)
        {
        {
          if (REG_IN_TABLE (i) >= 0 && REG_IN_TABLE (i) != REG_TICK (i))
          if (REG_IN_TABLE (i) >= 0 && REG_IN_TABLE (i) != REG_TICK (i))
            remove_invalid_refs (i);
            remove_invalid_refs (i);
 
 
          REG_IN_TABLE (i) = REG_TICK (i);
          REG_IN_TABLE (i) = REG_TICK (i);
          SUBREG_TICKED (i) = -1;
          SUBREG_TICKED (i) = -1;
        }
        }
 
 
      return 0;
      return 0;
    }
    }
 
 
  /* If this is a SUBREG, we don't want to discard other SUBREGs of the same
  /* If this is a SUBREG, we don't want to discard other SUBREGs of the same
     pseudo if they don't use overlapping words.  We handle only pseudos
     pseudo if they don't use overlapping words.  We handle only pseudos
     here for simplicity.  */
     here for simplicity.  */
  if (code == SUBREG && REG_P (SUBREG_REG (x))
  if (code == SUBREG && REG_P (SUBREG_REG (x))
      && REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER)
      && REGNO (SUBREG_REG (x)) >= FIRST_PSEUDO_REGISTER)
    {
    {
      unsigned int i = REGNO (SUBREG_REG (x));
      unsigned int i = REGNO (SUBREG_REG (x));
 
 
      if (REG_IN_TABLE (i) >= 0 && REG_IN_TABLE (i) != REG_TICK (i))
      if (REG_IN_TABLE (i) >= 0 && REG_IN_TABLE (i) != REG_TICK (i))
        {
        {
          /* If REG_IN_TABLE (i) differs from REG_TICK (i) by one, and
          /* If REG_IN_TABLE (i) differs from REG_TICK (i) by one, and
             the last store to this register really stored into this
             the last store to this register really stored into this
             subreg, then remove the memory of this subreg.
             subreg, then remove the memory of this subreg.
             Otherwise, remove any memory of the entire register and
             Otherwise, remove any memory of the entire register and
             all its subregs from the table.  */
             all its subregs from the table.  */
          if (REG_TICK (i) - REG_IN_TABLE (i) > 1
          if (REG_TICK (i) - REG_IN_TABLE (i) > 1
              || SUBREG_TICKED (i) != REGNO (SUBREG_REG (x)))
              || SUBREG_TICKED (i) != REGNO (SUBREG_REG (x)))
            remove_invalid_refs (i);
            remove_invalid_refs (i);
          else
          else
            remove_invalid_subreg_refs (i, SUBREG_BYTE (x), GET_MODE (x));
            remove_invalid_subreg_refs (i, SUBREG_BYTE (x), GET_MODE (x));
        }
        }
 
 
      REG_IN_TABLE (i) = REG_TICK (i);
      REG_IN_TABLE (i) = REG_TICK (i);
      SUBREG_TICKED (i) = REGNO (SUBREG_REG (x));
      SUBREG_TICKED (i) = REGNO (SUBREG_REG (x));
      return 0;
      return 0;
    }
    }
 
 
  /* If X is a comparison or a COMPARE and either operand is a register
  /* If X is a comparison or a COMPARE and either operand is a register
     that does not have a quantity, give it one.  This is so that a later
     that does not have a quantity, give it one.  This is so that a later
     call to record_jump_equiv won't cause X to be assigned a different
     call to record_jump_equiv won't cause X to be assigned a different
     hash code and not found in the table after that call.
     hash code and not found in the table after that call.
 
 
     It is not necessary to do this here, since rehash_using_reg can
     It is not necessary to do this here, since rehash_using_reg can
     fix up the table later, but doing this here eliminates the need to
     fix up the table later, but doing this here eliminates the need to
     call that expensive function in the most common case where the only
     call that expensive function in the most common case where the only
     use of the register is in the comparison.  */
     use of the register is in the comparison.  */
 
 
  if (code == COMPARE || COMPARISON_P (x))
  if (code == COMPARE || COMPARISON_P (x))
    {
    {
      if (REG_P (XEXP (x, 0))
      if (REG_P (XEXP (x, 0))
          && ! REGNO_QTY_VALID_P (REGNO (XEXP (x, 0))))
          && ! REGNO_QTY_VALID_P (REGNO (XEXP (x, 0))))
        if (insert_regs (XEXP (x, 0), NULL, 0))
        if (insert_regs (XEXP (x, 0), NULL, 0))
          {
          {
            rehash_using_reg (XEXP (x, 0));
            rehash_using_reg (XEXP (x, 0));
            changed = 1;
            changed = 1;
          }
          }
 
 
      if (REG_P (XEXP (x, 1))
      if (REG_P (XEXP (x, 1))
          && ! REGNO_QTY_VALID_P (REGNO (XEXP (x, 1))))
          && ! REGNO_QTY_VALID_P (REGNO (XEXP (x, 1))))
        if (insert_regs (XEXP (x, 1), NULL, 0))
        if (insert_regs (XEXP (x, 1), NULL, 0))
          {
          {
            rehash_using_reg (XEXP (x, 1));
            rehash_using_reg (XEXP (x, 1));
            changed = 1;
            changed = 1;
          }
          }
    }
    }
 
 
  fmt = GET_RTX_FORMAT (code);
  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    if (fmt[i] == 'e')
    if (fmt[i] == 'e')
      changed |= mention_regs (XEXP (x, i));
      changed |= mention_regs (XEXP (x, i));
    else if (fmt[i] == 'E')
    else if (fmt[i] == 'E')
      for (j = 0; j < XVECLEN (x, i); j++)
      for (j = 0; j < XVECLEN (x, i); j++)
        changed |= mention_regs (XVECEXP (x, i, j));
        changed |= mention_regs (XVECEXP (x, i, j));
 
 
  return changed;
  return changed;
}
}
 
 
/* Update the register quantities for inserting X into the hash table
/* Update the register quantities for inserting X into the hash table
   with a value equivalent to CLASSP.
   with a value equivalent to CLASSP.
   (If the class does not contain a REG, it is irrelevant.)
   (If the class does not contain a REG, it is irrelevant.)
   If MODIFIED is nonzero, X is a destination; it is being modified.
   If MODIFIED is nonzero, X is a destination; it is being modified.
   Note that delete_reg_equiv should be called on a register
   Note that delete_reg_equiv should be called on a register
   before insert_regs is done on that register with MODIFIED != 0.
   before insert_regs is done on that register with MODIFIED != 0.
 
 
   Nonzero value means that elements of reg_qty have changed
   Nonzero value means that elements of reg_qty have changed
   so X's hash code may be different.  */
   so X's hash code may be different.  */
 
 
static int
static int
insert_regs (rtx x, struct table_elt *classp, int modified)
insert_regs (rtx x, struct table_elt *classp, int modified)
{
{
  if (REG_P (x))
  if (REG_P (x))
    {
    {
      unsigned int regno = REGNO (x);
      unsigned int regno = REGNO (x);
      int qty_valid;
      int qty_valid;
 
 
      /* If REGNO is in the equivalence table already but is of the
      /* If REGNO is in the equivalence table already but is of the
         wrong mode for that equivalence, don't do anything here.  */
         wrong mode for that equivalence, don't do anything here.  */
 
 
      qty_valid = REGNO_QTY_VALID_P (regno);
      qty_valid = REGNO_QTY_VALID_P (regno);
      if (qty_valid)
      if (qty_valid)
        {
        {
          struct qty_table_elem *ent = &qty_table[REG_QTY (regno)];
          struct qty_table_elem *ent = &qty_table[REG_QTY (regno)];
 
 
          if (ent->mode != GET_MODE (x))
          if (ent->mode != GET_MODE (x))
            return 0;
            return 0;
        }
        }
 
 
      if (modified || ! qty_valid)
      if (modified || ! qty_valid)
        {
        {
          if (classp)
          if (classp)
            for (classp = classp->first_same_value;
            for (classp = classp->first_same_value;
                 classp != 0;
                 classp != 0;
                 classp = classp->next_same_value)
                 classp = classp->next_same_value)
              if (REG_P (classp->exp)
              if (REG_P (classp->exp)
                  && GET_MODE (classp->exp) == GET_MODE (x))
                  && GET_MODE (classp->exp) == GET_MODE (x))
                {
                {
                  unsigned c_regno = REGNO (classp->exp);
                  unsigned c_regno = REGNO (classp->exp);
 
 
                  gcc_assert (REGNO_QTY_VALID_P (c_regno));
                  gcc_assert (REGNO_QTY_VALID_P (c_regno));
 
 
                  /* Suppose that 5 is hard reg and 100 and 101 are
                  /* Suppose that 5 is hard reg and 100 and 101 are
                     pseudos.  Consider
                     pseudos.  Consider
 
 
                     (set (reg:si 100) (reg:si 5))
                     (set (reg:si 100) (reg:si 5))
                     (set (reg:si 5) (reg:si 100))
                     (set (reg:si 5) (reg:si 100))
                     (set (reg:di 101) (reg:di 5))
                     (set (reg:di 101) (reg:di 5))
 
 
                     We would now set REG_QTY (101) = REG_QTY (5), but the
                     We would now set REG_QTY (101) = REG_QTY (5), but the
                     entry for 5 is in SImode.  When we use this later in
                     entry for 5 is in SImode.  When we use this later in
                     copy propagation, we get the register in wrong mode.  */
                     copy propagation, we get the register in wrong mode.  */
                  if (qty_table[REG_QTY (c_regno)].mode != GET_MODE (x))
                  if (qty_table[REG_QTY (c_regno)].mode != GET_MODE (x))
                    continue;
                    continue;
 
 
                  make_regs_eqv (regno, c_regno);
                  make_regs_eqv (regno, c_regno);
                  return 1;
                  return 1;
                }
                }
 
 
          /* Mention_regs for a SUBREG checks if REG_TICK is exactly one larger
          /* Mention_regs for a SUBREG checks if REG_TICK is exactly one larger
             than REG_IN_TABLE to find out if there was only a single preceding
             than REG_IN_TABLE to find out if there was only a single preceding
             invalidation - for the SUBREG - or another one, which would be
             invalidation - for the SUBREG - or another one, which would be
             for the full register.  However, if we find here that REG_TICK
             for the full register.  However, if we find here that REG_TICK
             indicates that the register is invalid, it means that it has
             indicates that the register is invalid, it means that it has
             been invalidated in a separate operation.  The SUBREG might be used
             been invalidated in a separate operation.  The SUBREG might be used
             now (then this is a recursive call), or we might use the full REG
             now (then this is a recursive call), or we might use the full REG
             now and a SUBREG of it later.  So bump up REG_TICK so that
             now and a SUBREG of it later.  So bump up REG_TICK so that
             mention_regs will do the right thing.  */
             mention_regs will do the right thing.  */
          if (! modified
          if (! modified
              && REG_IN_TABLE (regno) >= 0
              && REG_IN_TABLE (regno) >= 0
              && REG_TICK (regno) == REG_IN_TABLE (regno) + 1)
              && REG_TICK (regno) == REG_IN_TABLE (regno) + 1)
            REG_TICK (regno)++;
            REG_TICK (regno)++;
          make_new_qty (regno, GET_MODE (x));
          make_new_qty (regno, GET_MODE (x));
          return 1;
          return 1;
        }
        }
 
 
      return 0;
      return 0;
    }
    }
 
 
  /* If X is a SUBREG, we will likely be inserting the inner register in the
  /* If X is a SUBREG, we will likely be inserting the inner register in the
     table.  If that register doesn't have an assigned quantity number at
     table.  If that register doesn't have an assigned quantity number at
     this point but does later, the insertion that we will be doing now will
     this point but does later, the insertion that we will be doing now will
     not be accessible because its hash code will have changed.  So assign
     not be accessible because its hash code will have changed.  So assign
     a quantity number now.  */
     a quantity number now.  */
 
 
  else if (GET_CODE (x) == SUBREG && REG_P (SUBREG_REG (x))
  else if (GET_CODE (x) == SUBREG && REG_P (SUBREG_REG (x))
           && ! REGNO_QTY_VALID_P (REGNO (SUBREG_REG (x))))
           && ! REGNO_QTY_VALID_P (REGNO (SUBREG_REG (x))))
    {
    {
      insert_regs (SUBREG_REG (x), NULL, 0);
      insert_regs (SUBREG_REG (x), NULL, 0);
      mention_regs (x);
      mention_regs (x);
      return 1;
      return 1;
    }
    }
  else
  else
    return mention_regs (x);
    return mention_regs (x);
}
}


/* Look in or update the hash table.  */
/* Look in or update the hash table.  */
 
 
/* Remove table element ELT from use in the table.
/* Remove table element ELT from use in the table.
   HASH is its hash code, made using the HASH macro.
   HASH is its hash code, made using the HASH macro.
   It's an argument because often that is known in advance
   It's an argument because often that is known in advance
   and we save much time not recomputing it.  */
   and we save much time not recomputing it.  */
 
 
static void
static void
remove_from_table (struct table_elt *elt, unsigned int hash)
remove_from_table (struct table_elt *elt, unsigned int hash)
{
{
  if (elt == 0)
  if (elt == 0)
    return;
    return;
 
 
  /* Mark this element as removed.  See cse_insn.  */
  /* Mark this element as removed.  See cse_insn.  */
  elt->first_same_value = 0;
  elt->first_same_value = 0;
 
 
  /* Remove the table element from its equivalence class.  */
  /* Remove the table element from its equivalence class.  */
 
 
  {
  {
    struct table_elt *prev = elt->prev_same_value;
    struct table_elt *prev = elt->prev_same_value;
    struct table_elt *next = elt->next_same_value;
    struct table_elt *next = elt->next_same_value;
 
 
    if (next)
    if (next)
      next->prev_same_value = prev;
      next->prev_same_value = prev;
 
 
    if (prev)
    if (prev)
      prev->next_same_value = next;
      prev->next_same_value = next;
    else
    else
      {
      {
        struct table_elt *newfirst = next;
        struct table_elt *newfirst = next;
        while (next)
        while (next)
          {
          {
            next->first_same_value = newfirst;
            next->first_same_value = newfirst;
            next = next->next_same_value;
            next = next->next_same_value;
          }
          }
      }
      }
  }
  }
 
 
  /* Remove the table element from its hash bucket.  */
  /* Remove the table element from its hash bucket.  */
 
 
  {
  {
    struct table_elt *prev = elt->prev_same_hash;
    struct table_elt *prev = elt->prev_same_hash;
    struct table_elt *next = elt->next_same_hash;
    struct table_elt *next = elt->next_same_hash;
 
 
    if (next)
    if (next)
      next->prev_same_hash = prev;
      next->prev_same_hash = prev;
 
 
    if (prev)
    if (prev)
      prev->next_same_hash = next;
      prev->next_same_hash = next;
    else if (table[hash] == elt)
    else if (table[hash] == elt)
      table[hash] = next;
      table[hash] = next;
    else
    else
      {
      {
        /* This entry is not in the proper hash bucket.  This can happen
        /* This entry is not in the proper hash bucket.  This can happen
           when two classes were merged by `merge_equiv_classes'.  Search
           when two classes were merged by `merge_equiv_classes'.  Search
           for the hash bucket that it heads.  This happens only very
           for the hash bucket that it heads.  This happens only very
           rarely, so the cost is acceptable.  */
           rarely, so the cost is acceptable.  */
        for (hash = 0; hash < HASH_SIZE; hash++)
        for (hash = 0; hash < HASH_SIZE; hash++)
          if (table[hash] == elt)
          if (table[hash] == elt)
            table[hash] = next;
            table[hash] = next;
      }
      }
  }
  }
 
 
  /* Remove the table element from its related-value circular chain.  */
  /* Remove the table element from its related-value circular chain.  */
 
 
  if (elt->related_value != 0 && elt->related_value != elt)
  if (elt->related_value != 0 && elt->related_value != elt)
    {
    {
      struct table_elt *p = elt->related_value;
      struct table_elt *p = elt->related_value;
 
 
      while (p->related_value != elt)
      while (p->related_value != elt)
        p = p->related_value;
        p = p->related_value;
      p->related_value = elt->related_value;
      p->related_value = elt->related_value;
      if (p->related_value == p)
      if (p->related_value == p)
        p->related_value = 0;
        p->related_value = 0;
    }
    }
 
 
  /* Now add it to the free element chain.  */
  /* Now add it to the free element chain.  */
  elt->next_same_hash = free_element_chain;
  elt->next_same_hash = free_element_chain;
  free_element_chain = elt;
  free_element_chain = elt;
 
 
  table_size--;
  table_size--;
}
}
 
 
/* Look up X in the hash table and return its table element,
/* Look up X in the hash table and return its table element,
   or 0 if X is not in the table.
   or 0 if X is not in the table.
 
 
   MODE is the machine-mode of X, or if X is an integer constant
   MODE is the machine-mode of X, or if X is an integer constant
   with VOIDmode then MODE is the mode with which X will be used.
   with VOIDmode then MODE is the mode with which X will be used.
 
 
   Here we are satisfied to find an expression whose tree structure
   Here we are satisfied to find an expression whose tree structure
   looks like X.  */
   looks like X.  */
 
 
static struct table_elt *
static struct table_elt *
lookup (rtx x, unsigned int hash, enum machine_mode mode)
lookup (rtx x, unsigned int hash, enum machine_mode mode)
{
{
  struct table_elt *p;
  struct table_elt *p;
 
 
  for (p = table[hash]; p; p = p->next_same_hash)
  for (p = table[hash]; p; p = p->next_same_hash)
    if (mode == p->mode && ((x == p->exp && REG_P (x))
    if (mode == p->mode && ((x == p->exp && REG_P (x))
                            || exp_equiv_p (x, p->exp, !REG_P (x), false)))
                            || exp_equiv_p (x, p->exp, !REG_P (x), false)))
      return p;
      return p;
 
 
  return 0;
  return 0;
}
}
 
 
/* Like `lookup' but don't care whether the table element uses invalid regs.
/* Like `lookup' but don't care whether the table element uses invalid regs.
   Also ignore discrepancies in the machine mode of a register.  */
   Also ignore discrepancies in the machine mode of a register.  */
 
 
static struct table_elt *
static struct table_elt *
lookup_for_remove (rtx x, unsigned int hash, enum machine_mode mode)
lookup_for_remove (rtx x, unsigned int hash, enum machine_mode mode)
{
{
  struct table_elt *p;
  struct table_elt *p;
 
 
  if (REG_P (x))
  if (REG_P (x))
    {
    {
      unsigned int regno = REGNO (x);
      unsigned int regno = REGNO (x);
 
 
      /* Don't check the machine mode when comparing registers;
      /* Don't check the machine mode when comparing registers;
         invalidating (REG:SI 0) also invalidates (REG:DF 0).  */
         invalidating (REG:SI 0) also invalidates (REG:DF 0).  */
      for (p = table[hash]; p; p = p->next_same_hash)
      for (p = table[hash]; p; p = p->next_same_hash)
        if (REG_P (p->exp)
        if (REG_P (p->exp)
            && REGNO (p->exp) == regno)
            && REGNO (p->exp) == regno)
          return p;
          return p;
    }
    }
  else
  else
    {
    {
      for (p = table[hash]; p; p = p->next_same_hash)
      for (p = table[hash]; p; p = p->next_same_hash)
        if (mode == p->mode
        if (mode == p->mode
            && (x == p->exp || exp_equiv_p (x, p->exp, 0, false)))
            && (x == p->exp || exp_equiv_p (x, p->exp, 0, false)))
          return p;
          return p;
    }
    }
 
 
  return 0;
  return 0;
}
}
 
 
/* Look for an expression equivalent to X and with code CODE.
/* Look for an expression equivalent to X and with code CODE.
   If one is found, return that expression.  */
   If one is found, return that expression.  */
 
 
static rtx
static rtx
lookup_as_function (rtx x, enum rtx_code code)
lookup_as_function (rtx x, enum rtx_code code)
{
{
  struct table_elt *p
  struct table_elt *p
    = lookup (x, SAFE_HASH (x, VOIDmode), GET_MODE (x));
    = lookup (x, SAFE_HASH (x, VOIDmode), GET_MODE (x));
 
 
  /* If we are looking for a CONST_INT, the mode doesn't really matter, as
  /* If we are looking for a CONST_INT, the mode doesn't really matter, as
     long as we are narrowing.  So if we looked in vain for a mode narrower
     long as we are narrowing.  So if we looked in vain for a mode narrower
     than word_mode before, look for word_mode now.  */
     than word_mode before, look for word_mode now.  */
  if (p == 0 && code == CONST_INT
  if (p == 0 && code == CONST_INT
      && GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (word_mode))
      && GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (word_mode))
    {
    {
      x = copy_rtx (x);
      x = copy_rtx (x);
      PUT_MODE (x, word_mode);
      PUT_MODE (x, word_mode);
      p = lookup (x, SAFE_HASH (x, VOIDmode), word_mode);
      p = lookup (x, SAFE_HASH (x, VOIDmode), word_mode);
    }
    }
 
 
  if (p == 0)
  if (p == 0)
    return 0;
    return 0;
 
 
  for (p = p->first_same_value; p; p = p->next_same_value)
  for (p = p->first_same_value; p; p = p->next_same_value)
    if (GET_CODE (p->exp) == code
    if (GET_CODE (p->exp) == code
        /* Make sure this is a valid entry in the table.  */
        /* Make sure this is a valid entry in the table.  */
        && exp_equiv_p (p->exp, p->exp, 1, false))
        && exp_equiv_p (p->exp, p->exp, 1, false))
      return p->exp;
      return p->exp;
 
 
  return 0;
  return 0;
}
}
 
 
/* Insert X in the hash table, assuming HASH is its hash code
/* Insert X in the hash table, assuming HASH is its hash code
   and CLASSP is an element of the class it should go in
   and CLASSP is an element of the class it should go in
   (or 0 if a new class should be made).
   (or 0 if a new class should be made).
   It is inserted at the proper position to keep the class in
   It is inserted at the proper position to keep the class in
   the order cheapest first.
   the order cheapest first.
 
 
   MODE is the machine-mode of X, or if X is an integer constant
   MODE is the machine-mode of X, or if X is an integer constant
   with VOIDmode then MODE is the mode with which X will be used.
   with VOIDmode then MODE is the mode with which X will be used.
 
 
   For elements of equal cheapness, the most recent one
   For elements of equal cheapness, the most recent one
   goes in front, except that the first element in the list
   goes in front, except that the first element in the list
   remains first unless a cheaper element is added.  The order of
   remains first unless a cheaper element is added.  The order of
   pseudo-registers does not matter, as canon_reg will be called to
   pseudo-registers does not matter, as canon_reg will be called to
   find the cheapest when a register is retrieved from the table.
   find the cheapest when a register is retrieved from the table.
 
 
   The in_memory field in the hash table element is set to 0.
   The in_memory field in the hash table element is set to 0.
   The caller must set it nonzero if appropriate.
   The caller must set it nonzero if appropriate.
 
 
   You should call insert_regs (X, CLASSP, MODIFY) before calling here,
   You should call insert_regs (X, CLASSP, MODIFY) before calling here,
   and if insert_regs returns a nonzero value
   and if insert_regs returns a nonzero value
   you must then recompute its hash code before calling here.
   you must then recompute its hash code before calling here.
 
 
   If necessary, update table showing constant values of quantities.  */
   If necessary, update table showing constant values of quantities.  */
 
 
#define CHEAPER(X, Y) \
#define CHEAPER(X, Y) \
 (preferable ((X)->cost, (X)->regcost, (Y)->cost, (Y)->regcost) < 0)
 (preferable ((X)->cost, (X)->regcost, (Y)->cost, (Y)->regcost) < 0)
 
 
static struct table_elt *
static struct table_elt *
insert (rtx x, struct table_elt *classp, unsigned int hash, enum machine_mode mode)
insert (rtx x, struct table_elt *classp, unsigned int hash, enum machine_mode mode)
{
{
  struct table_elt *elt;
  struct table_elt *elt;
 
 
  /* If X is a register and we haven't made a quantity for it,
  /* If X is a register and we haven't made a quantity for it,
     something is wrong.  */
     something is wrong.  */
  gcc_assert (!REG_P (x) || REGNO_QTY_VALID_P (REGNO (x)));
  gcc_assert (!REG_P (x) || REGNO_QTY_VALID_P (REGNO (x)));
 
 
  /* If X is a hard register, show it is being put in the table.  */
  /* If X is a hard register, show it is being put in the table.  */
  if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
  if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
    {
    {
      unsigned int regno = REGNO (x);
      unsigned int regno = REGNO (x);
      unsigned int endregno = regno + hard_regno_nregs[regno][GET_MODE (x)];
      unsigned int endregno = regno + hard_regno_nregs[regno][GET_MODE (x)];
      unsigned int i;
      unsigned int i;
 
 
      for (i = regno; i < endregno; i++)
      for (i = regno; i < endregno; i++)
        SET_HARD_REG_BIT (hard_regs_in_table, i);
        SET_HARD_REG_BIT (hard_regs_in_table, i);
    }
    }
 
 
  /* Put an element for X into the right hash bucket.  */
  /* Put an element for X into the right hash bucket.  */
 
 
  elt = free_element_chain;
  elt = free_element_chain;
  if (elt)
  if (elt)
    free_element_chain = elt->next_same_hash;
    free_element_chain = elt->next_same_hash;
  else
  else
    elt = XNEW (struct table_elt);
    elt = XNEW (struct table_elt);
 
 
  elt->exp = x;
  elt->exp = x;
  elt->canon_exp = NULL_RTX;
  elt->canon_exp = NULL_RTX;
  elt->cost = COST (x);
  elt->cost = COST (x);
  elt->regcost = approx_reg_cost (x);
  elt->regcost = approx_reg_cost (x);
  elt->next_same_value = 0;
  elt->next_same_value = 0;
  elt->prev_same_value = 0;
  elt->prev_same_value = 0;
  elt->next_same_hash = table[hash];
  elt->next_same_hash = table[hash];
  elt->prev_same_hash = 0;
  elt->prev_same_hash = 0;
  elt->related_value = 0;
  elt->related_value = 0;
  elt->in_memory = 0;
  elt->in_memory = 0;
  elt->mode = mode;
  elt->mode = mode;
  elt->is_const = (CONSTANT_P (x) || fixed_base_plus_p (x));
  elt->is_const = (CONSTANT_P (x) || fixed_base_plus_p (x));
 
 
  if (table[hash])
  if (table[hash])
    table[hash]->prev_same_hash = elt;
    table[hash]->prev_same_hash = elt;
  table[hash] = elt;
  table[hash] = elt;
 
 
  /* Put it into the proper value-class.  */
  /* Put it into the proper value-class.  */
  if (classp)
  if (classp)
    {
    {
      classp = classp->first_same_value;
      classp = classp->first_same_value;
      if (CHEAPER (elt, classp))
      if (CHEAPER (elt, classp))
        /* Insert at the head of the class.  */
        /* Insert at the head of the class.  */
        {
        {
          struct table_elt *p;
          struct table_elt *p;
          elt->next_same_value = classp;
          elt->next_same_value = classp;
          classp->prev_same_value = elt;
          classp->prev_same_value = elt;
          elt->first_same_value = elt;
          elt->first_same_value = elt;
 
 
          for (p = classp; p; p = p->next_same_value)
          for (p = classp; p; p = p->next_same_value)
            p->first_same_value = elt;
            p->first_same_value = elt;
        }
        }
      else
      else
        {
        {
          /* Insert not at head of the class.  */
          /* Insert not at head of the class.  */
          /* Put it after the last element cheaper than X.  */
          /* Put it after the last element cheaper than X.  */
          struct table_elt *p, *next;
          struct table_elt *p, *next;
 
 
          for (p = classp; (next = p->next_same_value) && CHEAPER (next, elt);
          for (p = classp; (next = p->next_same_value) && CHEAPER (next, elt);
               p = next);
               p = next);
 
 
          /* Put it after P and before NEXT.  */
          /* Put it after P and before NEXT.  */
          elt->next_same_value = next;
          elt->next_same_value = next;
          if (next)
          if (next)
            next->prev_same_value = elt;
            next->prev_same_value = elt;
 
 
          elt->prev_same_value = p;
          elt->prev_same_value = p;
          p->next_same_value = elt;
          p->next_same_value = elt;
          elt->first_same_value = classp;
          elt->first_same_value = classp;
        }
        }
    }
    }
  else
  else
    elt->first_same_value = elt;
    elt->first_same_value = elt;
 
 
  /* If this is a constant being set equivalent to a register or a register
  /* If this is a constant being set equivalent to a register or a register
     being set equivalent to a constant, note the constant equivalence.
     being set equivalent to a constant, note the constant equivalence.
 
 
     If this is a constant, it cannot be equivalent to a different constant,
     If this is a constant, it cannot be equivalent to a different constant,
     and a constant is the only thing that can be cheaper than a register.  So
     and a constant is the only thing that can be cheaper than a register.  So
     we know the register is the head of the class (before the constant was
     we know the register is the head of the class (before the constant was
     inserted).
     inserted).
 
 
     If this is a register that is not already known equivalent to a
     If this is a register that is not already known equivalent to a
     constant, we must check the entire class.
     constant, we must check the entire class.
 
 
     If this is a register that is already known equivalent to an insn,
     If this is a register that is already known equivalent to an insn,
     update the qtys `const_insn' to show that `this_insn' is the latest
     update the qtys `const_insn' to show that `this_insn' is the latest
     insn making that quantity equivalent to the constant.  */
     insn making that quantity equivalent to the constant.  */
 
 
  if (elt->is_const && classp && REG_P (classp->exp)
  if (elt->is_const && classp && REG_P (classp->exp)
      && !REG_P (x))
      && !REG_P (x))
    {
    {
      int exp_q = REG_QTY (REGNO (classp->exp));
      int exp_q = REG_QTY (REGNO (classp->exp));
      struct qty_table_elem *exp_ent = &qty_table[exp_q];
      struct qty_table_elem *exp_ent = &qty_table[exp_q];
 
 
      exp_ent->const_rtx = gen_lowpart (exp_ent->mode, x);
      exp_ent->const_rtx = gen_lowpart (exp_ent->mode, x);
      exp_ent->const_insn = this_insn;
      exp_ent->const_insn = this_insn;
    }
    }
 
 
  else if (REG_P (x)
  else if (REG_P (x)
           && classp
           && classp
           && ! qty_table[REG_QTY (REGNO (x))].const_rtx
           && ! qty_table[REG_QTY (REGNO (x))].const_rtx
           && ! elt->is_const)
           && ! elt->is_const)
    {
    {
      struct table_elt *p;
      struct table_elt *p;
 
 
      for (p = classp; p != 0; p = p->next_same_value)
      for (p = classp; p != 0; p = p->next_same_value)
        {
        {
          if (p->is_const && !REG_P (p->exp))
          if (p->is_const && !REG_P (p->exp))
            {
            {
              int x_q = REG_QTY (REGNO (x));
              int x_q = REG_QTY (REGNO (x));
              struct qty_table_elem *x_ent = &qty_table[x_q];
              struct qty_table_elem *x_ent = &qty_table[x_q];
 
 
              x_ent->const_rtx
              x_ent->const_rtx
                = gen_lowpart (GET_MODE (x), p->exp);
                = gen_lowpart (GET_MODE (x), p->exp);
              x_ent->const_insn = this_insn;
              x_ent->const_insn = this_insn;
              break;
              break;
            }
            }
        }
        }
    }
    }
 
 
  else if (REG_P (x)
  else if (REG_P (x)
           && qty_table[REG_QTY (REGNO (x))].const_rtx
           && qty_table[REG_QTY (REGNO (x))].const_rtx
           && GET_MODE (x) == qty_table[REG_QTY (REGNO (x))].mode)
           && GET_MODE (x) == qty_table[REG_QTY (REGNO (x))].mode)
    qty_table[REG_QTY (REGNO (x))].const_insn = this_insn;
    qty_table[REG_QTY (REGNO (x))].const_insn = this_insn;
 
 
  /* If this is a constant with symbolic value,
  /* If this is a constant with symbolic value,
     and it has a term with an explicit integer value,
     and it has a term with an explicit integer value,
     link it up with related expressions.  */
     link it up with related expressions.  */
  if (GET_CODE (x) == CONST)
  if (GET_CODE (x) == CONST)
    {
    {
      rtx subexp = get_related_value (x);
      rtx subexp = get_related_value (x);
      unsigned subhash;
      unsigned subhash;
      struct table_elt *subelt, *subelt_prev;
      struct table_elt *subelt, *subelt_prev;
 
 
      if (subexp != 0)
      if (subexp != 0)
        {
        {
          /* Get the integer-free subexpression in the hash table.  */
          /* Get the integer-free subexpression in the hash table.  */
          subhash = SAFE_HASH (subexp, mode);
          subhash = SAFE_HASH (subexp, mode);
          subelt = lookup (subexp, subhash, mode);
          subelt = lookup (subexp, subhash, mode);
          if (subelt == 0)
          if (subelt == 0)
            subelt = insert (subexp, NULL, subhash, mode);
            subelt = insert (subexp, NULL, subhash, mode);
          /* Initialize SUBELT's circular chain if it has none.  */
          /* Initialize SUBELT's circular chain if it has none.  */
          if (subelt->related_value == 0)
          if (subelt->related_value == 0)
            subelt->related_value = subelt;
            subelt->related_value = subelt;
          /* Find the element in the circular chain that precedes SUBELT.  */
          /* Find the element in the circular chain that precedes SUBELT.  */
          subelt_prev = subelt;
          subelt_prev = subelt;
          while (subelt_prev->related_value != subelt)
          while (subelt_prev->related_value != subelt)
            subelt_prev = subelt_prev->related_value;
            subelt_prev = subelt_prev->related_value;
          /* Put new ELT into SUBELT's circular chain just before SUBELT.
          /* Put new ELT into SUBELT's circular chain just before SUBELT.
             This way the element that follows SUBELT is the oldest one.  */
             This way the element that follows SUBELT is the oldest one.  */
          elt->related_value = subelt_prev->related_value;
          elt->related_value = subelt_prev->related_value;
          subelt_prev->related_value = elt;
          subelt_prev->related_value = elt;
        }
        }
    }
    }
 
 
  table_size++;
  table_size++;
 
 
  return elt;
  return elt;
}
}


/* Given two equivalence classes, CLASS1 and CLASS2, put all the entries from
/* Given two equivalence classes, CLASS1 and CLASS2, put all the entries from
   CLASS2 into CLASS1.  This is done when we have reached an insn which makes
   CLASS2 into CLASS1.  This is done when we have reached an insn which makes
   the two classes equivalent.
   the two classes equivalent.
 
 
   CLASS1 will be the surviving class; CLASS2 should not be used after this
   CLASS1 will be the surviving class; CLASS2 should not be used after this
   call.
   call.
 
 
   Any invalid entries in CLASS2 will not be copied.  */
   Any invalid entries in CLASS2 will not be copied.  */
 
 
static void
static void
merge_equiv_classes (struct table_elt *class1, struct table_elt *class2)
merge_equiv_classes (struct table_elt *class1, struct table_elt *class2)
{
{
  struct table_elt *elt, *next, *new;
  struct table_elt *elt, *next, *new;
 
 
  /* Ensure we start with the head of the classes.  */
  /* Ensure we start with the head of the classes.  */
  class1 = class1->first_same_value;
  class1 = class1->first_same_value;
  class2 = class2->first_same_value;
  class2 = class2->first_same_value;
 
 
  /* If they were already equal, forget it.  */
  /* If they were already equal, forget it.  */
  if (class1 == class2)
  if (class1 == class2)
    return;
    return;
 
 
  for (elt = class2; elt; elt = next)
  for (elt = class2; elt; elt = next)
    {
    {
      unsigned int hash;
      unsigned int hash;
      rtx exp = elt->exp;
      rtx exp = elt->exp;
      enum machine_mode mode = elt->mode;
      enum machine_mode mode = elt->mode;
 
 
      next = elt->next_same_value;
      next = elt->next_same_value;
 
 
      /* Remove old entry, make a new one in CLASS1's class.
      /* Remove old entry, make a new one in CLASS1's class.
         Don't do this for invalid entries as we cannot find their
         Don't do this for invalid entries as we cannot find their
         hash code (it also isn't necessary).  */
         hash code (it also isn't necessary).  */
      if (REG_P (exp) || exp_equiv_p (exp, exp, 1, false))
      if (REG_P (exp) || exp_equiv_p (exp, exp, 1, false))
        {
        {
          bool need_rehash = false;
          bool need_rehash = false;
 
 
          hash_arg_in_memory = 0;
          hash_arg_in_memory = 0;
          hash = HASH (exp, mode);
          hash = HASH (exp, mode);
 
 
          if (REG_P (exp))
          if (REG_P (exp))
            {
            {
              need_rehash = REGNO_QTY_VALID_P (REGNO (exp));
              need_rehash = REGNO_QTY_VALID_P (REGNO (exp));
              delete_reg_equiv (REGNO (exp));
              delete_reg_equiv (REGNO (exp));
            }
            }
 
 
          remove_from_table (elt, hash);
          remove_from_table (elt, hash);
 
 
          if (insert_regs (exp, class1, 0) || need_rehash)
          if (insert_regs (exp, class1, 0) || need_rehash)
            {
            {
              rehash_using_reg (exp);
              rehash_using_reg (exp);
              hash = HASH (exp, mode);
              hash = HASH (exp, mode);
            }
            }
          new = insert (exp, class1, hash, mode);
          new = insert (exp, class1, hash, mode);
          new->in_memory = hash_arg_in_memory;
          new->in_memory = hash_arg_in_memory;
        }
        }
    }
    }
}
}


/* Flush the entire hash table.  */
/* Flush the entire hash table.  */
 
 
static void
static void
flush_hash_table (void)
flush_hash_table (void)
{
{
  int i;
  int i;
  struct table_elt *p;
  struct table_elt *p;
 
 
  for (i = 0; i < HASH_SIZE; i++)
  for (i = 0; i < HASH_SIZE; i++)
    for (p = table[i]; p; p = table[i])
    for (p = table[i]; p; p = table[i])
      {
      {
        /* Note that invalidate can remove elements
        /* Note that invalidate can remove elements
           after P in the current hash chain.  */
           after P in the current hash chain.  */
        if (REG_P (p->exp))
        if (REG_P (p->exp))
          invalidate (p->exp, VOIDmode);
          invalidate (p->exp, VOIDmode);
        else
        else
          remove_from_table (p, i);
          remove_from_table (p, i);
      }
      }
}
}


/* Function called for each rtx to check whether true dependence exist.  */
/* Function called for each rtx to check whether true dependence exist.  */
struct check_dependence_data
struct check_dependence_data
{
{
  enum machine_mode mode;
  enum machine_mode mode;
  rtx exp;
  rtx exp;
  rtx addr;
  rtx addr;
};
};
 
 
static int
static int
check_dependence (rtx *x, void *data)
check_dependence (rtx *x, void *data)
{
{
  struct check_dependence_data *d = (struct check_dependence_data *) data;
  struct check_dependence_data *d = (struct check_dependence_data *) data;
  if (*x && MEM_P (*x))
  if (*x && MEM_P (*x))
    return canon_true_dependence (d->exp, d->mode, d->addr, *x,
    return canon_true_dependence (d->exp, d->mode, d->addr, *x,
                                  cse_rtx_varies_p);
                                  cse_rtx_varies_p);
  else
  else
    return 0;
    return 0;
}
}


/* Remove from the hash table, or mark as invalid, all expressions whose
/* Remove from the hash table, or mark as invalid, all expressions whose
   values could be altered by storing in X.  X is a register, a subreg, or
   values could be altered by storing in X.  X is a register, a subreg, or
   a memory reference with nonvarying address (because, when a memory
   a memory reference with nonvarying address (because, when a memory
   reference with a varying address is stored in, all memory references are
   reference with a varying address is stored in, all memory references are
   removed by invalidate_memory so specific invalidation is superfluous).
   removed by invalidate_memory so specific invalidation is superfluous).
   FULL_MODE, if not VOIDmode, indicates that this much should be
   FULL_MODE, if not VOIDmode, indicates that this much should be
   invalidated instead of just the amount indicated by the mode of X.  This
   invalidated instead of just the amount indicated by the mode of X.  This
   is only used for bitfield stores into memory.
   is only used for bitfield stores into memory.
 
 
   A nonvarying address may be just a register or just a symbol reference,
   A nonvarying address may be just a register or just a symbol reference,
   or it may be either of those plus a numeric offset.  */
   or it may be either of those plus a numeric offset.  */
 
 
static void
static void
invalidate (rtx x, enum machine_mode full_mode)
invalidate (rtx x, enum machine_mode full_mode)
{
{
  int i;
  int i;
  struct table_elt *p;
  struct table_elt *p;
  rtx addr;
  rtx addr;
 
 
  switch (GET_CODE (x))
  switch (GET_CODE (x))
    {
    {
    case REG:
    case REG:
      {
      {
        /* If X is a register, dependencies on its contents are recorded
        /* If X is a register, dependencies on its contents are recorded
           through the qty number mechanism.  Just change the qty number of
           through the qty number mechanism.  Just change the qty number of
           the register, mark it as invalid for expressions that refer to it,
           the register, mark it as invalid for expressions that refer to it,
           and remove it itself.  */
           and remove it itself.  */
        unsigned int regno = REGNO (x);
        unsigned int regno = REGNO (x);
        unsigned int hash = HASH (x, GET_MODE (x));
        unsigned int hash = HASH (x, GET_MODE (x));
 
 
        /* Remove REGNO from any quantity list it might be on and indicate
        /* Remove REGNO from any quantity list it might be on and indicate
           that its value might have changed.  If it is a pseudo, remove its
           that its value might have changed.  If it is a pseudo, remove its
           entry from the hash table.
           entry from the hash table.
 
 
           For a hard register, we do the first two actions above for any
           For a hard register, we do the first two actions above for any
           additional hard registers corresponding to X.  Then, if any of these
           additional hard registers corresponding to X.  Then, if any of these
           registers are in the table, we must remove any REG entries that
           registers are in the table, we must remove any REG entries that
           overlap these registers.  */
           overlap these registers.  */
 
 
        delete_reg_equiv (regno);
        delete_reg_equiv (regno);
        REG_TICK (regno)++;
        REG_TICK (regno)++;
        SUBREG_TICKED (regno) = -1;
        SUBREG_TICKED (regno) = -1;
 
 
        if (regno >= FIRST_PSEUDO_REGISTER)
        if (regno >= FIRST_PSEUDO_REGISTER)
          {
          {
            /* Because a register can be referenced in more than one mode,
            /* Because a register can be referenced in more than one mode,
               we might have to remove more than one table entry.  */
               we might have to remove more than one table entry.  */
            struct table_elt *elt;
            struct table_elt *elt;
 
 
            while ((elt = lookup_for_remove (x, hash, GET_MODE (x))))
            while ((elt = lookup_for_remove (x, hash, GET_MODE (x))))
              remove_from_table (elt, hash);
              remove_from_table (elt, hash);
          }
          }
        else
        else
          {
          {
            HOST_WIDE_INT in_table
            HOST_WIDE_INT in_table
              = TEST_HARD_REG_BIT (hard_regs_in_table, regno);
              = TEST_HARD_REG_BIT (hard_regs_in_table, regno);
            unsigned int endregno
            unsigned int endregno
              = regno + hard_regno_nregs[regno][GET_MODE (x)];
              = regno + hard_regno_nregs[regno][GET_MODE (x)];
            unsigned int tregno, tendregno, rn;
            unsigned int tregno, tendregno, rn;
            struct table_elt *p, *next;
            struct table_elt *p, *next;
 
 
            CLEAR_HARD_REG_BIT (hard_regs_in_table, regno);
            CLEAR_HARD_REG_BIT (hard_regs_in_table, regno);
 
 
            for (rn = regno + 1; rn < endregno; rn++)
            for (rn = regno + 1; rn < endregno; rn++)
              {
              {
                in_table |= TEST_HARD_REG_BIT (hard_regs_in_table, rn);
                in_table |= TEST_HARD_REG_BIT (hard_regs_in_table, rn);
                CLEAR_HARD_REG_BIT (hard_regs_in_table, rn);
                CLEAR_HARD_REG_BIT (hard_regs_in_table, rn);
                delete_reg_equiv (rn);
                delete_reg_equiv (rn);
                REG_TICK (rn)++;
                REG_TICK (rn)++;
                SUBREG_TICKED (rn) = -1;
                SUBREG_TICKED (rn) = -1;
              }
              }
 
 
            if (in_table)
            if (in_table)
              for (hash = 0; hash < HASH_SIZE; hash++)
              for (hash = 0; hash < HASH_SIZE; hash++)
                for (p = table[hash]; p; p = next)
                for (p = table[hash]; p; p = next)
                  {
                  {
                    next = p->next_same_hash;
                    next = p->next_same_hash;
 
 
                    if (!REG_P (p->exp)
                    if (!REG_P (p->exp)
                        || REGNO (p->exp) >= FIRST_PSEUDO_REGISTER)
                        || REGNO (p->exp) >= FIRST_PSEUDO_REGISTER)
                      continue;
                      continue;
 
 
                    tregno = REGNO (p->exp);
                    tregno = REGNO (p->exp);
                    tendregno
                    tendregno
                      = tregno + hard_regno_nregs[tregno][GET_MODE (p->exp)];
                      = tregno + hard_regno_nregs[tregno][GET_MODE (p->exp)];
                    if (tendregno > regno && tregno < endregno)
                    if (tendregno > regno && tregno < endregno)
                      remove_from_table (p, hash);
                      remove_from_table (p, hash);
                  }
                  }
          }
          }
      }
      }
      return;
      return;
 
 
    case SUBREG:
    case SUBREG:
      invalidate (SUBREG_REG (x), VOIDmode);
      invalidate (SUBREG_REG (x), VOIDmode);
      return;
      return;
 
 
    case PARALLEL:
    case PARALLEL:
      for (i = XVECLEN (x, 0) - 1; i >= 0; --i)
      for (i = XVECLEN (x, 0) - 1; i >= 0; --i)
        invalidate (XVECEXP (x, 0, i), VOIDmode);
        invalidate (XVECEXP (x, 0, i), VOIDmode);
      return;
      return;
 
 
    case EXPR_LIST:
    case EXPR_LIST:
      /* This is part of a disjoint return value; extract the location in
      /* This is part of a disjoint return value; extract the location in
         question ignoring the offset.  */
         question ignoring the offset.  */
      invalidate (XEXP (x, 0), VOIDmode);
      invalidate (XEXP (x, 0), VOIDmode);
      return;
      return;
 
 
    case MEM:
    case MEM:
      addr = canon_rtx (get_addr (XEXP (x, 0)));
      addr = canon_rtx (get_addr (XEXP (x, 0)));
      /* Calculate the canonical version of X here so that
      /* Calculate the canonical version of X here so that
         true_dependence doesn't generate new RTL for X on each call.  */
         true_dependence doesn't generate new RTL for X on each call.  */
      x = canon_rtx (x);
      x = canon_rtx (x);
 
 
      /* Remove all hash table elements that refer to overlapping pieces of
      /* Remove all hash table elements that refer to overlapping pieces of
         memory.  */
         memory.  */
      if (full_mode == VOIDmode)
      if (full_mode == VOIDmode)
        full_mode = GET_MODE (x);
        full_mode = GET_MODE (x);
 
 
      for (i = 0; i < HASH_SIZE; i++)
      for (i = 0; i < HASH_SIZE; i++)
        {
        {
          struct table_elt *next;
          struct table_elt *next;
 
 
          for (p = table[i]; p; p = next)
          for (p = table[i]; p; p = next)
            {
            {
              next = p->next_same_hash;
              next = p->next_same_hash;
              if (p->in_memory)
              if (p->in_memory)
                {
                {
                  struct check_dependence_data d;
                  struct check_dependence_data d;
 
 
                  /* Just canonicalize the expression once;
                  /* Just canonicalize the expression once;
                     otherwise each time we call invalidate
                     otherwise each time we call invalidate
                     true_dependence will canonicalize the
                     true_dependence will canonicalize the
                     expression again.  */
                     expression again.  */
                  if (!p->canon_exp)
                  if (!p->canon_exp)
                    p->canon_exp = canon_rtx (p->exp);
                    p->canon_exp = canon_rtx (p->exp);
                  d.exp = x;
                  d.exp = x;
                  d.addr = addr;
                  d.addr = addr;
                  d.mode = full_mode;
                  d.mode = full_mode;
                  if (for_each_rtx (&p->canon_exp, check_dependence, &d))
                  if (for_each_rtx (&p->canon_exp, check_dependence, &d))
                    remove_from_table (p, i);
                    remove_from_table (p, i);
                }
                }
            }
            }
        }
        }
      return;
      return;
 
 
    default:
    default:
      gcc_unreachable ();
      gcc_unreachable ();
    }
    }
}
}


/* Remove all expressions that refer to register REGNO,
/* Remove all expressions that refer to register REGNO,
   since they are already invalid, and we are about to
   since they are already invalid, and we are about to
   mark that register valid again and don't want the old
   mark that register valid again and don't want the old
   expressions to reappear as valid.  */
   expressions to reappear as valid.  */
 
 
static void
static void
remove_invalid_refs (unsigned int regno)
remove_invalid_refs (unsigned int regno)
{
{
  unsigned int i;
  unsigned int i;
  struct table_elt *p, *next;
  struct table_elt *p, *next;
 
 
  for (i = 0; i < HASH_SIZE; i++)
  for (i = 0; i < HASH_SIZE; i++)
    for (p = table[i]; p; p = next)
    for (p = table[i]; p; p = next)
      {
      {
        next = p->next_same_hash;
        next = p->next_same_hash;
        if (!REG_P (p->exp)
        if (!REG_P (p->exp)
            && refers_to_regno_p (regno, regno + 1, p->exp, (rtx *) 0))
            && refers_to_regno_p (regno, regno + 1, p->exp, (rtx *) 0))
          remove_from_table (p, i);
          remove_from_table (p, i);
      }
      }
}
}
 
 
/* Likewise for a subreg with subreg_reg REGNO, subreg_byte OFFSET,
/* Likewise for a subreg with subreg_reg REGNO, subreg_byte OFFSET,
   and mode MODE.  */
   and mode MODE.  */
static void
static void
remove_invalid_subreg_refs (unsigned int regno, unsigned int offset,
remove_invalid_subreg_refs (unsigned int regno, unsigned int offset,
                            enum machine_mode mode)
                            enum machine_mode mode)
{
{
  unsigned int i;
  unsigned int i;
  struct table_elt *p, *next;
  struct table_elt *p, *next;
  unsigned int end = offset + (GET_MODE_SIZE (mode) - 1);
  unsigned int end = offset + (GET_MODE_SIZE (mode) - 1);
 
 
  for (i = 0; i < HASH_SIZE; i++)
  for (i = 0; i < HASH_SIZE; i++)
    for (p = table[i]; p; p = next)
    for (p = table[i]; p; p = next)
      {
      {
        rtx exp = p->exp;
        rtx exp = p->exp;
        next = p->next_same_hash;
        next = p->next_same_hash;
 
 
        if (!REG_P (exp)
        if (!REG_P (exp)
            && (GET_CODE (exp) != SUBREG
            && (GET_CODE (exp) != SUBREG
                || !REG_P (SUBREG_REG (exp))
                || !REG_P (SUBREG_REG (exp))
                || REGNO (SUBREG_REG (exp)) != regno
                || REGNO (SUBREG_REG (exp)) != regno
                || (((SUBREG_BYTE (exp)
                || (((SUBREG_BYTE (exp)
                      + (GET_MODE_SIZE (GET_MODE (exp)) - 1)) >= offset)
                      + (GET_MODE_SIZE (GET_MODE (exp)) - 1)) >= offset)
                    && SUBREG_BYTE (exp) <= end))
                    && SUBREG_BYTE (exp) <= end))
            && refers_to_regno_p (regno, regno + 1, p->exp, (rtx *) 0))
            && refers_to_regno_p (regno, regno + 1, p->exp, (rtx *) 0))
          remove_from_table (p, i);
          remove_from_table (p, i);
      }
      }
}
}


/* Recompute the hash codes of any valid entries in the hash table that
/* Recompute the hash codes of any valid entries in the hash table that
   reference X, if X is a register, or SUBREG_REG (X) if X is a SUBREG.
   reference X, if X is a register, or SUBREG_REG (X) if X is a SUBREG.
 
 
   This is called when we make a jump equivalence.  */
   This is called when we make a jump equivalence.  */
 
 
static void
static void
rehash_using_reg (rtx x)
rehash_using_reg (rtx x)
{
{
  unsigned int i;
  unsigned int i;
  struct table_elt *p, *next;
  struct table_elt *p, *next;
  unsigned hash;
  unsigned hash;
 
 
  if (GET_CODE (x) == SUBREG)
  if (GET_CODE (x) == SUBREG)
    x = SUBREG_REG (x);
    x = SUBREG_REG (x);
 
 
  /* If X is not a register or if the register is known not to be in any
  /* If X is not a register or if the register is known not to be in any
     valid entries in the table, we have no work to do.  */
     valid entries in the table, we have no work to do.  */
 
 
  if (!REG_P (x)
  if (!REG_P (x)
      || REG_IN_TABLE (REGNO (x)) < 0
      || REG_IN_TABLE (REGNO (x)) < 0
      || REG_IN_TABLE (REGNO (x)) != REG_TICK (REGNO (x)))
      || REG_IN_TABLE (REGNO (x)) != REG_TICK (REGNO (x)))
    return;
    return;
 
 
  /* Scan all hash chains looking for valid entries that mention X.
  /* Scan all hash chains looking for valid entries that mention X.
     If we find one and it is in the wrong hash chain, move it.  */
     If we find one and it is in the wrong hash chain, move it.  */
 
 
  for (i = 0; i < HASH_SIZE; i++)
  for (i = 0; i < HASH_SIZE; i++)
    for (p = table[i]; p; p = next)
    for (p = table[i]; p; p = next)
      {
      {
        next = p->next_same_hash;
        next = p->next_same_hash;
        if (reg_mentioned_p (x, p->exp)
        if (reg_mentioned_p (x, p->exp)
            && exp_equiv_p (p->exp, p->exp, 1, false)
            && exp_equiv_p (p->exp, p->exp, 1, false)
            && i != (hash = SAFE_HASH (p->exp, p->mode)))
            && i != (hash = SAFE_HASH (p->exp, p->mode)))
          {
          {
            if (p->next_same_hash)
            if (p->next_same_hash)
              p->next_same_hash->prev_same_hash = p->prev_same_hash;
              p->next_same_hash->prev_same_hash = p->prev_same_hash;
 
 
            if (p->prev_same_hash)
            if (p->prev_same_hash)
              p->prev_same_hash->next_same_hash = p->next_same_hash;
              p->prev_same_hash->next_same_hash = p->next_same_hash;
            else
            else
              table[i] = p->next_same_hash;
              table[i] = p->next_same_hash;
 
 
            p->next_same_hash = table[hash];
            p->next_same_hash = table[hash];
            p->prev_same_hash = 0;
            p->prev_same_hash = 0;
            if (table[hash])
            if (table[hash])
              table[hash]->prev_same_hash = p;
              table[hash]->prev_same_hash = p;
            table[hash] = p;
            table[hash] = p;
          }
          }
      }
      }
}
}


/* Remove from the hash table any expression that is a call-clobbered
/* Remove from the hash table any expression that is a call-clobbered
   register.  Also update their TICK values.  */
   register.  Also update their TICK values.  */
 
 
static void
static void
invalidate_for_call (void)
invalidate_for_call (void)
{
{
  unsigned int regno, endregno;
  unsigned int regno, endregno;
  unsigned int i;
  unsigned int i;
  unsigned hash;
  unsigned hash;
  struct table_elt *p, *next;
  struct table_elt *p, *next;
  int in_table = 0;
  int in_table = 0;
 
 
  /* Go through all the hard registers.  For each that is clobbered in
  /* Go through all the hard registers.  For each that is clobbered in
     a CALL_INSN, remove the register from quantity chains and update
     a CALL_INSN, remove the register from quantity chains and update
     reg_tick if defined.  Also see if any of these registers is currently
     reg_tick if defined.  Also see if any of these registers is currently
     in the table.  */
     in the table.  */
 
 
  for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
  for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
    if (TEST_HARD_REG_BIT (regs_invalidated_by_call, regno))
    if (TEST_HARD_REG_BIT (regs_invalidated_by_call, regno))
      {
      {
        delete_reg_equiv (regno);
        delete_reg_equiv (regno);
        if (REG_TICK (regno) >= 0)
        if (REG_TICK (regno) >= 0)
          {
          {
            REG_TICK (regno)++;
            REG_TICK (regno)++;
            SUBREG_TICKED (regno) = -1;
            SUBREG_TICKED (regno) = -1;
          }
          }
 
 
        in_table |= (TEST_HARD_REG_BIT (hard_regs_in_table, regno) != 0);
        in_table |= (TEST_HARD_REG_BIT (hard_regs_in_table, regno) != 0);
      }
      }
 
 
  /* In the case where we have no call-clobbered hard registers in the
  /* In the case where we have no call-clobbered hard registers in the
     table, we are done.  Otherwise, scan the table and remove any
     table, we are done.  Otherwise, scan the table and remove any
     entry that overlaps a call-clobbered register.  */
     entry that overlaps a call-clobbered register.  */
 
 
  if (in_table)
  if (in_table)
    for (hash = 0; hash < HASH_SIZE; hash++)
    for (hash = 0; hash < HASH_SIZE; hash++)
      for (p = table[hash]; p; p = next)
      for (p = table[hash]; p; p = next)
        {
        {
          next = p->next_same_hash;
          next = p->next_same_hash;
 
 
          if (!REG_P (p->exp)
          if (!REG_P (p->exp)
              || REGNO (p->exp) >= FIRST_PSEUDO_REGISTER)
              || REGNO (p->exp) >= FIRST_PSEUDO_REGISTER)
            continue;
            continue;
 
 
          regno = REGNO (p->exp);
          regno = REGNO (p->exp);
          endregno = regno + hard_regno_nregs[regno][GET_MODE (p->exp)];
          endregno = regno + hard_regno_nregs[regno][GET_MODE (p->exp)];
 
 
          for (i = regno; i < endregno; i++)
          for (i = regno; i < endregno; i++)
            if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
            if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
              {
              {
                remove_from_table (p, hash);
                remove_from_table (p, hash);
                break;
                break;
              }
              }
        }
        }
}
}


/* Given an expression X of type CONST,
/* Given an expression X of type CONST,
   and ELT which is its table entry (or 0 if it
   and ELT which is its table entry (or 0 if it
   is not in the hash table),
   is not in the hash table),
   return an alternate expression for X as a register plus integer.
   return an alternate expression for X as a register plus integer.
   If none can be found, return 0.  */
   If none can be found, return 0.  */
 
 
static rtx
static rtx
use_related_value (rtx x, struct table_elt *elt)
use_related_value (rtx x, struct table_elt *elt)
{
{
  struct table_elt *relt = 0;
  struct table_elt *relt = 0;
  struct table_elt *p, *q;
  struct table_elt *p, *q;
  HOST_WIDE_INT offset;
  HOST_WIDE_INT offset;
 
 
  /* First, is there anything related known?
  /* First, is there anything related known?
     If we have a table element, we can tell from that.
     If we have a table element, we can tell from that.
     Otherwise, must look it up.  */
     Otherwise, must look it up.  */
 
 
  if (elt != 0 && elt->related_value != 0)
  if (elt != 0 && elt->related_value != 0)
    relt = elt;
    relt = elt;
  else if (elt == 0 && GET_CODE (x) == CONST)
  else if (elt == 0 && GET_CODE (x) == CONST)
    {
    {
      rtx subexp = get_related_value (x);
      rtx subexp = get_related_value (x);
      if (subexp != 0)
      if (subexp != 0)
        relt = lookup (subexp,
        relt = lookup (subexp,
                       SAFE_HASH (subexp, GET_MODE (subexp)),
                       SAFE_HASH (subexp, GET_MODE (subexp)),
                       GET_MODE (subexp));
                       GET_MODE (subexp));
    }
    }
 
 
  if (relt == 0)
  if (relt == 0)
    return 0;
    return 0;
 
 
  /* Search all related table entries for one that has an
  /* Search all related table entries for one that has an
     equivalent register.  */
     equivalent register.  */
 
 
  p = relt;
  p = relt;
  while (1)
  while (1)
    {
    {
      /* This loop is strange in that it is executed in two different cases.
      /* This loop is strange in that it is executed in two different cases.
         The first is when X is already in the table.  Then it is searching
         The first is when X is already in the table.  Then it is searching
         the RELATED_VALUE list of X's class (RELT).  The second case is when
         the RELATED_VALUE list of X's class (RELT).  The second case is when
         X is not in the table.  Then RELT points to a class for the related
         X is not in the table.  Then RELT points to a class for the related
         value.
         value.
 
 
         Ensure that, whatever case we are in, that we ignore classes that have
         Ensure that, whatever case we are in, that we ignore classes that have
         the same value as X.  */
         the same value as X.  */
 
 
      if (rtx_equal_p (x, p->exp))
      if (rtx_equal_p (x, p->exp))
        q = 0;
        q = 0;
      else
      else
        for (q = p->first_same_value; q; q = q->next_same_value)
        for (q = p->first_same_value; q; q = q->next_same_value)
          if (REG_P (q->exp))
          if (REG_P (q->exp))
            break;
            break;
 
 
      if (q)
      if (q)
        break;
        break;
 
 
      p = p->related_value;
      p = p->related_value;
 
 
      /* We went all the way around, so there is nothing to be found.
      /* We went all the way around, so there is nothing to be found.
         Alternatively, perhaps RELT was in the table for some other reason
         Alternatively, perhaps RELT was in the table for some other reason
         and it has no related values recorded.  */
         and it has no related values recorded.  */
      if (p == relt || p == 0)
      if (p == relt || p == 0)
        break;
        break;
    }
    }
 
 
  if (q == 0)
  if (q == 0)
    return 0;
    return 0;
 
 
  offset = (get_integer_term (x) - get_integer_term (p->exp));
  offset = (get_integer_term (x) - get_integer_term (p->exp));
  /* Note: OFFSET may be 0 if P->xexp and X are related by commutativity.  */
  /* Note: OFFSET may be 0 if P->xexp and X are related by commutativity.  */
  return plus_constant (q->exp, offset);
  return plus_constant (q->exp, offset);
}
}


/* Hash a string.  Just add its bytes up.  */
/* Hash a string.  Just add its bytes up.  */
static inline unsigned
static inline unsigned
hash_rtx_string (const char *ps)
hash_rtx_string (const char *ps)
{
{
  unsigned hash = 0;
  unsigned hash = 0;
  const unsigned char *p = (const unsigned char *) ps;
  const unsigned char *p = (const unsigned char *) ps;
 
 
  if (p)
  if (p)
    while (*p)
    while (*p)
      hash += *p++;
      hash += *p++;
 
 
  return hash;
  return hash;
}
}
 
 
/* Hash an rtx.  We are careful to make sure the value is never negative.
/* Hash an rtx.  We are careful to make sure the value is never negative.
   Equivalent registers hash identically.
   Equivalent registers hash identically.
   MODE is used in hashing for CONST_INTs only;
   MODE is used in hashing for CONST_INTs only;
   otherwise the mode of X is used.
   otherwise the mode of X is used.
 
 
   Store 1 in DO_NOT_RECORD_P if any subexpression is volatile.
   Store 1 in DO_NOT_RECORD_P if any subexpression is volatile.
 
 
   If HASH_ARG_IN_MEMORY_P is not NULL, store 1 in it if X contains
   If HASH_ARG_IN_MEMORY_P is not NULL, store 1 in it if X contains
   a MEM rtx which does not have the RTX_UNCHANGING_P bit set.
   a MEM rtx which does not have the RTX_UNCHANGING_P bit set.
 
 
   Note that cse_insn knows that the hash code of a MEM expression
   Note that cse_insn knows that the hash code of a MEM expression
   is just (int) MEM plus the hash code of the address.  */
   is just (int) MEM plus the hash code of the address.  */
 
 
unsigned
unsigned
hash_rtx (rtx x, enum machine_mode mode, int *do_not_record_p,
hash_rtx (rtx x, enum machine_mode mode, int *do_not_record_p,
          int *hash_arg_in_memory_p, bool have_reg_qty)
          int *hash_arg_in_memory_p, bool have_reg_qty)
{
{
  int i, j;
  int i, j;
  unsigned hash = 0;
  unsigned hash = 0;
  enum rtx_code code;
  enum rtx_code code;
  const char *fmt;
  const char *fmt;
 
 
  /* Used to turn recursion into iteration.  We can't rely on GCC's
  /* Used to turn recursion into iteration.  We can't rely on GCC's
     tail-recursion elimination since we need to keep accumulating values
     tail-recursion elimination since we need to keep accumulating values
     in HASH.  */
     in HASH.  */
 repeat:
 repeat:
  if (x == 0)
  if (x == 0)
    return hash;
    return hash;
 
 
  code = GET_CODE (x);
  code = GET_CODE (x);
  switch (code)
  switch (code)
    {
    {
    case REG:
    case REG:
      {
      {
        unsigned int regno = REGNO (x);
        unsigned int regno = REGNO (x);
 
 
        if (!reload_completed)
        if (!reload_completed)
          {
          {
            /* On some machines, we can't record any non-fixed hard register,
            /* On some machines, we can't record any non-fixed hard register,
               because extending its life will cause reload problems.  We
               because extending its life will cause reload problems.  We
               consider ap, fp, sp, gp to be fixed for this purpose.
               consider ap, fp, sp, gp to be fixed for this purpose.
 
 
               We also consider CCmode registers to be fixed for this purpose;
               We also consider CCmode registers to be fixed for this purpose;
               failure to do so leads to failure to simplify 0<100 type of
               failure to do so leads to failure to simplify 0<100 type of
               conditionals.
               conditionals.
 
 
               On all machines, we can't record any global registers.
               On all machines, we can't record any global registers.
               Nor should we record any register that is in a small
               Nor should we record any register that is in a small
               class, as defined by CLASS_LIKELY_SPILLED_P.  */
               class, as defined by CLASS_LIKELY_SPILLED_P.  */
            bool record;
            bool record;
 
 
            if (regno >= FIRST_PSEUDO_REGISTER)
            if (regno >= FIRST_PSEUDO_REGISTER)
              record = true;
              record = true;
            else if (x == frame_pointer_rtx
            else if (x == frame_pointer_rtx
                     || x == hard_frame_pointer_rtx
                     || x == hard_frame_pointer_rtx
                     || x == arg_pointer_rtx
                     || x == arg_pointer_rtx
                     || x == stack_pointer_rtx
                     || x == stack_pointer_rtx
                     || x == pic_offset_table_rtx)
                     || x == pic_offset_table_rtx)
              record = true;
              record = true;
            else if (global_regs[regno])
            else if (global_regs[regno])
              record = false;
              record = false;
            else if (fixed_regs[regno])
            else if (fixed_regs[regno])
              record = true;
              record = true;
            else if (GET_MODE_CLASS (GET_MODE (x)) == MODE_CC)
            else if (GET_MODE_CLASS (GET_MODE (x)) == MODE_CC)
              record = true;
              record = true;
            else if (SMALL_REGISTER_CLASSES)
            else if (SMALL_REGISTER_CLASSES)
              record = false;
              record = false;
            else if (CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (regno)))
            else if (CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (regno)))
              record = false;
              record = false;
            else
            else
              record = true;
              record = true;
 
 
            if (!record)
            if (!record)
              {
              {
                *do_not_record_p = 1;
                *do_not_record_p = 1;
                return 0;
                return 0;
              }
              }
          }
          }
 
 
        hash += ((unsigned int) REG << 7);
        hash += ((unsigned int) REG << 7);
        hash += (have_reg_qty ? (unsigned) REG_QTY (regno) : regno);
        hash += (have_reg_qty ? (unsigned) REG_QTY (regno) : regno);
        return hash;
        return hash;
      }
      }
 
 
    /* We handle SUBREG of a REG specially because the underlying
    /* We handle SUBREG of a REG specially because the underlying
       reg changes its hash value with every value change; we don't
       reg changes its hash value with every value change; we don't
       want to have to forget unrelated subregs when one subreg changes.  */
       want to have to forget unrelated subregs when one subreg changes.  */
    case SUBREG:
    case SUBREG:
      {
      {
        if (REG_P (SUBREG_REG (x)))
        if (REG_P (SUBREG_REG (x)))
          {
          {
            hash += (((unsigned int) SUBREG << 7)
            hash += (((unsigned int) SUBREG << 7)
                     + REGNO (SUBREG_REG (x))
                     + REGNO (SUBREG_REG (x))
                     + (SUBREG_BYTE (x) / UNITS_PER_WORD));
                     + (SUBREG_BYTE (x) / UNITS_PER_WORD));
            return hash;
            return hash;
          }
          }
        break;
        break;
      }
      }
 
 
    case CONST_INT:
    case CONST_INT:
      hash += (((unsigned int) CONST_INT << 7) + (unsigned int) mode
      hash += (((unsigned int) CONST_INT << 7) + (unsigned int) mode
               + (unsigned int) INTVAL (x));
               + (unsigned int) INTVAL (x));
      return hash;
      return hash;
 
 
    case CONST_DOUBLE:
    case CONST_DOUBLE:
      /* This is like the general case, except that it only counts
      /* This is like the general case, except that it only counts
         the integers representing the constant.  */
         the integers representing the constant.  */
      hash += (unsigned int) code + (unsigned int) GET_MODE (x);
      hash += (unsigned int) code + (unsigned int) GET_MODE (x);
      if (GET_MODE (x) != VOIDmode)
      if (GET_MODE (x) != VOIDmode)
        hash += real_hash (CONST_DOUBLE_REAL_VALUE (x));
        hash += real_hash (CONST_DOUBLE_REAL_VALUE (x));
      else
      else
        hash += ((unsigned int) CONST_DOUBLE_LOW (x)
        hash += ((unsigned int) CONST_DOUBLE_LOW (x)
                 + (unsigned int) CONST_DOUBLE_HIGH (x));
                 + (unsigned int) CONST_DOUBLE_HIGH (x));
      return hash;
      return hash;
 
 
    case CONST_VECTOR:
    case CONST_VECTOR:
      {
      {
        int units;
        int units;
        rtx elt;
        rtx elt;
 
 
        units = CONST_VECTOR_NUNITS (x);
        units = CONST_VECTOR_NUNITS (x);
 
 
        for (i = 0; i < units; ++i)
        for (i = 0; i < units; ++i)
          {
          {
            elt = CONST_VECTOR_ELT (x, i);
            elt = CONST_VECTOR_ELT (x, i);
            hash += hash_rtx (elt, GET_MODE (elt), do_not_record_p,
            hash += hash_rtx (elt, GET_MODE (elt), do_not_record_p,
                              hash_arg_in_memory_p, have_reg_qty);
                              hash_arg_in_memory_p, have_reg_qty);
          }
          }
 
 
        return hash;
        return hash;
      }
      }
 
 
      /* Assume there is only one rtx object for any given label.  */
      /* Assume there is only one rtx object for any given label.  */
    case LABEL_REF:
    case LABEL_REF:
      /* We don't hash on the address of the CODE_LABEL to avoid bootstrap
      /* We don't hash on the address of the CODE_LABEL to avoid bootstrap
         differences and differences between each stage's debugging dumps.  */
         differences and differences between each stage's debugging dumps.  */
         hash += (((unsigned int) LABEL_REF << 7)
         hash += (((unsigned int) LABEL_REF << 7)
                  + CODE_LABEL_NUMBER (XEXP (x, 0)));
                  + CODE_LABEL_NUMBER (XEXP (x, 0)));
      return hash;
      return hash;
 
 
    case SYMBOL_REF:
    case SYMBOL_REF:
      {
      {
        /* Don't hash on the symbol's address to avoid bootstrap differences.
        /* Don't hash on the symbol's address to avoid bootstrap differences.
           Different hash values may cause expressions to be recorded in
           Different hash values may cause expressions to be recorded in
           different orders and thus different registers to be used in the
           different orders and thus different registers to be used in the
           final assembler.  This also avoids differences in the dump files
           final assembler.  This also avoids differences in the dump files
           between various stages.  */
           between various stages.  */
        unsigned int h = 0;
        unsigned int h = 0;
        const unsigned char *p = (const unsigned char *) XSTR (x, 0);
        const unsigned char *p = (const unsigned char *) XSTR (x, 0);
 
 
        while (*p)
        while (*p)
          h += (h << 7) + *p++; /* ??? revisit */
          h += (h << 7) + *p++; /* ??? revisit */
 
 
        hash += ((unsigned int) SYMBOL_REF << 7) + h;
        hash += ((unsigned int) SYMBOL_REF << 7) + h;
        return hash;
        return hash;
      }
      }
 
 
    case MEM:
    case MEM:
      /* We don't record if marked volatile or if BLKmode since we don't
      /* We don't record if marked volatile or if BLKmode since we don't
         know the size of the move.  */
         know the size of the move.  */
      if (MEM_VOLATILE_P (x) || GET_MODE (x) == BLKmode)
      if (MEM_VOLATILE_P (x) || GET_MODE (x) == BLKmode)
        {
        {
          *do_not_record_p = 1;
          *do_not_record_p = 1;
          return 0;
          return 0;
        }
        }
      if (hash_arg_in_memory_p && !MEM_READONLY_P (x))
      if (hash_arg_in_memory_p && !MEM_READONLY_P (x))
        *hash_arg_in_memory_p = 1;
        *hash_arg_in_memory_p = 1;
 
 
      /* Now that we have already found this special case,
      /* Now that we have already found this special case,
         might as well speed it up as much as possible.  */
         might as well speed it up as much as possible.  */
      hash += (unsigned) MEM;
      hash += (unsigned) MEM;
      x = XEXP (x, 0);
      x = XEXP (x, 0);
      goto repeat;
      goto repeat;
 
 
    case USE:
    case USE:
      /* A USE that mentions non-volatile memory needs special
      /* A USE that mentions non-volatile memory needs special
         handling since the MEM may be BLKmode which normally
         handling since the MEM may be BLKmode which normally
         prevents an entry from being made.  Pure calls are
         prevents an entry from being made.  Pure calls are
         marked by a USE which mentions BLKmode memory.
         marked by a USE which mentions BLKmode memory.
         See calls.c:emit_call_1.  */
         See calls.c:emit_call_1.  */
      if (MEM_P (XEXP (x, 0))
      if (MEM_P (XEXP (x, 0))
          && ! MEM_VOLATILE_P (XEXP (x, 0)))
          && ! MEM_VOLATILE_P (XEXP (x, 0)))
        {
        {
          hash += (unsigned) USE;
          hash += (unsigned) USE;
          x = XEXP (x, 0);
          x = XEXP (x, 0);
 
 
          if (hash_arg_in_memory_p && !MEM_READONLY_P (x))
          if (hash_arg_in_memory_p && !MEM_READONLY_P (x))
            *hash_arg_in_memory_p = 1;
            *hash_arg_in_memory_p = 1;
 
 
          /* Now that we have already found this special case,
          /* Now that we have already found this special case,
             might as well speed it up as much as possible.  */
             might as well speed it up as much as possible.  */
          hash += (unsigned) MEM;
          hash += (unsigned) MEM;
          x = XEXP (x, 0);
          x = XEXP (x, 0);
          goto repeat;
          goto repeat;
        }
        }
      break;
      break;
 
 
    case PRE_DEC:
    case PRE_DEC:
    case PRE_INC:
    case PRE_INC:
    case POST_DEC:
    case POST_DEC:
    case POST_INC:
    case POST_INC:
    case PRE_MODIFY:
    case PRE_MODIFY:
    case POST_MODIFY:
    case POST_MODIFY:
    case PC:
    case PC:
    case CC0:
    case CC0:
    case CALL:
    case CALL:
    case UNSPEC_VOLATILE:
    case UNSPEC_VOLATILE:
      *do_not_record_p = 1;
      *do_not_record_p = 1;
      return 0;
      return 0;
 
 
    case ASM_OPERANDS:
    case ASM_OPERANDS:
      if (MEM_VOLATILE_P (x))
      if (MEM_VOLATILE_P (x))
        {
        {
          *do_not_record_p = 1;
          *do_not_record_p = 1;
          return 0;
          return 0;
        }
        }
      else
      else
        {
        {
          /* We don't want to take the filename and line into account.  */
          /* We don't want to take the filename and line into account.  */
          hash += (unsigned) code + (unsigned) GET_MODE (x)
          hash += (unsigned) code + (unsigned) GET_MODE (x)
            + hash_rtx_string (ASM_OPERANDS_TEMPLATE (x))
            + hash_rtx_string (ASM_OPERANDS_TEMPLATE (x))
            + hash_rtx_string (ASM_OPERANDS_OUTPUT_CONSTRAINT (x))
            + hash_rtx_string (ASM_OPERANDS_OUTPUT_CONSTRAINT (x))
            + (unsigned) ASM_OPERANDS_OUTPUT_IDX (x);
            + (unsigned) ASM_OPERANDS_OUTPUT_IDX (x);
 
 
          if (ASM_OPERANDS_INPUT_LENGTH (x))
          if (ASM_OPERANDS_INPUT_LENGTH (x))
            {
            {
              for (i = 1; i < ASM_OPERANDS_INPUT_LENGTH (x); i++)
              for (i = 1; i < ASM_OPERANDS_INPUT_LENGTH (x); i++)
                {
                {
                  hash += (hash_rtx (ASM_OPERANDS_INPUT (x, i),
                  hash += (hash_rtx (ASM_OPERANDS_INPUT (x, i),
                                     GET_MODE (ASM_OPERANDS_INPUT (x, i)),
                                     GET_MODE (ASM_OPERANDS_INPUT (x, i)),
                                     do_not_record_p, hash_arg_in_memory_p,
                                     do_not_record_p, hash_arg_in_memory_p,
                                     have_reg_qty)
                                     have_reg_qty)
                           + hash_rtx_string
                           + hash_rtx_string
                                (ASM_OPERANDS_INPUT_CONSTRAINT (x, i)));
                                (ASM_OPERANDS_INPUT_CONSTRAINT (x, i)));
                }
                }
 
 
              hash += hash_rtx_string (ASM_OPERANDS_INPUT_CONSTRAINT (x, 0));
              hash += hash_rtx_string (ASM_OPERANDS_INPUT_CONSTRAINT (x, 0));
              x = ASM_OPERANDS_INPUT (x, 0);
              x = ASM_OPERANDS_INPUT (x, 0);
              mode = GET_MODE (x);
              mode = GET_MODE (x);
              goto repeat;
              goto repeat;
            }
            }
 
 
          return hash;
          return hash;
        }
        }
      break;
      break;
 
 
    default:
    default:
      break;
      break;
    }
    }
 
 
  i = GET_RTX_LENGTH (code) - 1;
  i = GET_RTX_LENGTH (code) - 1;
  hash += (unsigned) code + (unsigned) GET_MODE (x);
  hash += (unsigned) code + (unsigned) GET_MODE (x);
  fmt = GET_RTX_FORMAT (code);
  fmt = GET_RTX_FORMAT (code);
  for (; i >= 0; i--)
  for (; i >= 0; i--)
    {
    {
      switch (fmt[i])
      switch (fmt[i])
        {
        {
        case 'e':
        case 'e':
          /* If we are about to do the last recursive call
          /* If we are about to do the last recursive call
             needed at this level, change it into iteration.
             needed at this level, change it into iteration.
             This function  is called enough to be worth it.  */
             This function  is called enough to be worth it.  */
          if (i == 0)
          if (i == 0)
            {
            {
              x = XEXP (x, i);
              x = XEXP (x, i);
              goto repeat;
              goto repeat;
            }
            }
 
 
          hash += hash_rtx (XEXP (x, i), 0, do_not_record_p,
          hash += hash_rtx (XEXP (x, i), 0, do_not_record_p,
                            hash_arg_in_memory_p, have_reg_qty);
                            hash_arg_in_memory_p, have_reg_qty);
          break;
          break;
 
 
        case 'E':
        case 'E':
          for (j = 0; j < XVECLEN (x, i); j++)
          for (j = 0; j < XVECLEN (x, i); j++)
            hash += hash_rtx (XVECEXP (x, i, j), 0, do_not_record_p,
            hash += hash_rtx (XVECEXP (x, i, j), 0, do_not_record_p,
                              hash_arg_in_memory_p, have_reg_qty);
                              hash_arg_in_memory_p, have_reg_qty);
          break;
          break;
 
 
        case 's':
        case 's':
          hash += hash_rtx_string (XSTR (x, i));
          hash += hash_rtx_string (XSTR (x, i));
          break;
          break;
 
 
        case 'i':
        case 'i':
          hash += (unsigned int) XINT (x, i);
          hash += (unsigned int) XINT (x, i);
          break;
          break;
 
 
        case '0': case 't':
        case '0': case 't':
          /* Unused.  */
          /* Unused.  */
          break;
          break;
 
 
        default:
        default:
          gcc_unreachable ();
          gcc_unreachable ();
        }
        }
    }
    }
 
 
  return hash;
  return hash;
}
}
 
 
/* Hash an rtx X for cse via hash_rtx.
/* Hash an rtx X for cse via hash_rtx.
   Stores 1 in do_not_record if any subexpression is volatile.
   Stores 1 in do_not_record if any subexpression is volatile.
   Stores 1 in hash_arg_in_memory if X contains a mem rtx which
   Stores 1 in hash_arg_in_memory if X contains a mem rtx which
   does not have the RTX_UNCHANGING_P bit set.  */
   does not have the RTX_UNCHANGING_P bit set.  */
 
 
static inline unsigned
static inline unsigned
canon_hash (rtx x, enum machine_mode mode)
canon_hash (rtx x, enum machine_mode mode)
{
{
  return hash_rtx (x, mode, &do_not_record, &hash_arg_in_memory, true);
  return hash_rtx (x, mode, &do_not_record, &hash_arg_in_memory, true);
}
}
 
 
/* Like canon_hash but with no side effects, i.e. do_not_record
/* Like canon_hash but with no side effects, i.e. do_not_record
   and hash_arg_in_memory are not changed.  */
   and hash_arg_in_memory are not changed.  */
 
 
static inline unsigned
static inline unsigned
safe_hash (rtx x, enum machine_mode mode)
safe_hash (rtx x, enum machine_mode mode)
{
{
  int dummy_do_not_record;
  int dummy_do_not_record;
  return hash_rtx (x, mode, &dummy_do_not_record, NULL, true);
  return hash_rtx (x, mode, &dummy_do_not_record, NULL, true);
}
}


/* Return 1 iff X and Y would canonicalize into the same thing,
/* Return 1 iff X and Y would canonicalize into the same thing,
   without actually constructing the canonicalization of either one.
   without actually constructing the canonicalization of either one.
   If VALIDATE is nonzero,
   If VALIDATE is nonzero,
   we assume X is an expression being processed from the rtl
   we assume X is an expression being processed from the rtl
   and Y was found in the hash table.  We check register refs
   and Y was found in the hash table.  We check register refs
   in Y for being marked as valid.
   in Y for being marked as valid.
 
 
   If FOR_GCSE is true, we compare X and Y for equivalence for GCSE.  */
   If FOR_GCSE is true, we compare X and Y for equivalence for GCSE.  */
 
 
int
int
exp_equiv_p (rtx x, rtx y, int validate, bool for_gcse)
exp_equiv_p (rtx x, rtx y, int validate, bool for_gcse)
{
{
  int i, j;
  int i, j;
  enum rtx_code code;
  enum rtx_code code;
  const char *fmt;
  const char *fmt;
 
 
  /* Note: it is incorrect to assume an expression is equivalent to itself
  /* Note: it is incorrect to assume an expression is equivalent to itself
     if VALIDATE is nonzero.  */
     if VALIDATE is nonzero.  */
  if (x == y && !validate)
  if (x == y && !validate)
    return 1;
    return 1;
 
 
  if (x == 0 || y == 0)
  if (x == 0 || y == 0)
    return x == y;
    return x == y;
 
 
  code = GET_CODE (x);
  code = GET_CODE (x);
  if (code != GET_CODE (y))
  if (code != GET_CODE (y))
    return 0;
    return 0;
 
 
  /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent.  */
  /* (MULT:SI x y) and (MULT:HI x y) are NOT equivalent.  */
  if (GET_MODE (x) != GET_MODE (y))
  if (GET_MODE (x) != GET_MODE (y))
    return 0;
    return 0;
 
 
  switch (code)
  switch (code)
    {
    {
    case PC:
    case PC:
    case CC0:
    case CC0:
    case CONST_INT:
    case CONST_INT:
    case CONST_DOUBLE:
    case CONST_DOUBLE:
      return x == y;
      return x == y;
 
 
    case LABEL_REF:
    case LABEL_REF:
      return XEXP (x, 0) == XEXP (y, 0);
      return XEXP (x, 0) == XEXP (y, 0);
 
 
    case SYMBOL_REF:
    case SYMBOL_REF:
      return XSTR (x, 0) == XSTR (y, 0);
      return XSTR (x, 0) == XSTR (y, 0);
 
 
    case REG:
    case REG:
      if (for_gcse)
      if (for_gcse)
        return REGNO (x) == REGNO (y);
        return REGNO (x) == REGNO (y);
      else
      else
        {
        {
          unsigned int regno = REGNO (y);
          unsigned int regno = REGNO (y);
          unsigned int i;
          unsigned int i;
          unsigned int endregno
          unsigned int endregno
            = regno + (regno >= FIRST_PSEUDO_REGISTER ? 1
            = regno + (regno >= FIRST_PSEUDO_REGISTER ? 1
                       : hard_regno_nregs[regno][GET_MODE (y)]);
                       : hard_regno_nregs[regno][GET_MODE (y)]);
 
 
          /* If the quantities are not the same, the expressions are not
          /* If the quantities are not the same, the expressions are not
             equivalent.  If there are and we are not to validate, they
             equivalent.  If there are and we are not to validate, they
             are equivalent.  Otherwise, ensure all regs are up-to-date.  */
             are equivalent.  Otherwise, ensure all regs are up-to-date.  */
 
 
          if (REG_QTY (REGNO (x)) != REG_QTY (regno))
          if (REG_QTY (REGNO (x)) != REG_QTY (regno))
            return 0;
            return 0;
 
 
          if (! validate)
          if (! validate)
            return 1;
            return 1;
 
 
          for (i = regno; i < endregno; i++)
          for (i = regno; i < endregno; i++)
            if (REG_IN_TABLE (i) != REG_TICK (i))
            if (REG_IN_TABLE (i) != REG_TICK (i))
              return 0;
              return 0;
 
 
          return 1;
          return 1;
        }
        }
 
 
    case MEM:
    case MEM:
      if (for_gcse)
      if (for_gcse)
        {
        {
          /* A volatile mem should not be considered equivalent to any
          /* A volatile mem should not be considered equivalent to any
             other.  */
             other.  */
          if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y))
          if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y))
            return 0;
            return 0;
 
 
          /* Can't merge two expressions in different alias sets, since we
          /* Can't merge two expressions in different alias sets, since we
             can decide that the expression is transparent in a block when
             can decide that the expression is transparent in a block when
             it isn't, due to it being set with the different alias set.
             it isn't, due to it being set with the different alias set.
 
 
             Also, can't merge two expressions with different MEM_ATTRS.
             Also, can't merge two expressions with different MEM_ATTRS.
             They could e.g. be two different entities allocated into the
             They could e.g. be two different entities allocated into the
             same space on the stack (see e.g. PR25130).  In that case, the
             same space on the stack (see e.g. PR25130).  In that case, the
             MEM addresses can be the same, even though the two MEMs are
             MEM addresses can be the same, even though the two MEMs are
             absolutely not equivalent.
             absolutely not equivalent.
 
 
             But because really all MEM attributes should be the same for
             But because really all MEM attributes should be the same for
             equivalent MEMs, we just use the invariant that MEMs that have
             equivalent MEMs, we just use the invariant that MEMs that have
             the same attributes share the same mem_attrs data structure.  */
             the same attributes share the same mem_attrs data structure.  */
          if (MEM_ATTRS (x) != MEM_ATTRS (y))
          if (MEM_ATTRS (x) != MEM_ATTRS (y))
            return 0;
            return 0;
        }
        }
      break;
      break;
 
 
    /*  For commutative operations, check both orders.  */
    /*  For commutative operations, check both orders.  */
    case PLUS:
    case PLUS:
    case MULT:
    case MULT:
    case AND:
    case AND:
    case IOR:
    case IOR:
    case XOR:
    case XOR:
    case NE:
    case NE:
    case EQ:
    case EQ:
      return ((exp_equiv_p (XEXP (x, 0), XEXP (y, 0),
      return ((exp_equiv_p (XEXP (x, 0), XEXP (y, 0),
                             validate, for_gcse)
                             validate, for_gcse)
               && exp_equiv_p (XEXP (x, 1), XEXP (y, 1),
               && exp_equiv_p (XEXP (x, 1), XEXP (y, 1),
                                validate, for_gcse))
                                validate, for_gcse))
              || (exp_equiv_p (XEXP (x, 0), XEXP (y, 1),
              || (exp_equiv_p (XEXP (x, 0), XEXP (y, 1),
                                validate, for_gcse)
                                validate, for_gcse)
                  && exp_equiv_p (XEXP (x, 1), XEXP (y, 0),
                  && exp_equiv_p (XEXP (x, 1), XEXP (y, 0),
                                   validate, for_gcse)));
                                   validate, for_gcse)));
 
 
    case ASM_OPERANDS:
    case ASM_OPERANDS:
      /* We don't use the generic code below because we want to
      /* We don't use the generic code below because we want to
         disregard filename and line numbers.  */
         disregard filename and line numbers.  */
 
 
      /* A volatile asm isn't equivalent to any other.  */
      /* A volatile asm isn't equivalent to any other.  */
      if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y))
      if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y))
        return 0;
        return 0;
 
 
      if (GET_MODE (x) != GET_MODE (y)
      if (GET_MODE (x) != GET_MODE (y)
          || strcmp (ASM_OPERANDS_TEMPLATE (x), ASM_OPERANDS_TEMPLATE (y))
          || strcmp (ASM_OPERANDS_TEMPLATE (x), ASM_OPERANDS_TEMPLATE (y))
          || strcmp (ASM_OPERANDS_OUTPUT_CONSTRAINT (x),
          || strcmp (ASM_OPERANDS_OUTPUT_CONSTRAINT (x),
                     ASM_OPERANDS_OUTPUT_CONSTRAINT (y))
                     ASM_OPERANDS_OUTPUT_CONSTRAINT (y))
          || ASM_OPERANDS_OUTPUT_IDX (x) != ASM_OPERANDS_OUTPUT_IDX (y)
          || ASM_OPERANDS_OUTPUT_IDX (x) != ASM_OPERANDS_OUTPUT_IDX (y)
          || ASM_OPERANDS_INPUT_LENGTH (x) != ASM_OPERANDS_INPUT_LENGTH (y))
          || ASM_OPERANDS_INPUT_LENGTH (x) != ASM_OPERANDS_INPUT_LENGTH (y))
        return 0;
        return 0;
 
 
      if (ASM_OPERANDS_INPUT_LENGTH (x))
      if (ASM_OPERANDS_INPUT_LENGTH (x))
        {
        {
          for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--)
          for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--)
            if (! exp_equiv_p (ASM_OPERANDS_INPUT (x, i),
            if (! exp_equiv_p (ASM_OPERANDS_INPUT (x, i),
                               ASM_OPERANDS_INPUT (y, i),
                               ASM_OPERANDS_INPUT (y, i),
                               validate, for_gcse)
                               validate, for_gcse)
                || strcmp (ASM_OPERANDS_INPUT_CONSTRAINT (x, i),
                || strcmp (ASM_OPERANDS_INPUT_CONSTRAINT (x, i),
                           ASM_OPERANDS_INPUT_CONSTRAINT (y, i)))
                           ASM_OPERANDS_INPUT_CONSTRAINT (y, i)))
              return 0;
              return 0;
        }
        }
 
 
      return 1;
      return 1;
 
 
    default:
    default:
      break;
      break;
    }
    }
 
 
  /* Compare the elements.  If any pair of corresponding elements
  /* Compare the elements.  If any pair of corresponding elements
     fail to match, return 0 for the whole thing.  */
     fail to match, return 0 for the whole thing.  */
 
 
  fmt = GET_RTX_FORMAT (code);
  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
    {
      switch (fmt[i])
      switch (fmt[i])
        {
        {
        case 'e':
        case 'e':
          if (! exp_equiv_p (XEXP (x, i), XEXP (y, i),
          if (! exp_equiv_p (XEXP (x, i), XEXP (y, i),
                              validate, for_gcse))
                              validate, for_gcse))
            return 0;
            return 0;
          break;
          break;
 
 
        case 'E':
        case 'E':
          if (XVECLEN (x, i) != XVECLEN (y, i))
          if (XVECLEN (x, i) != XVECLEN (y, i))
            return 0;
            return 0;
          for (j = 0; j < XVECLEN (x, i); j++)
          for (j = 0; j < XVECLEN (x, i); j++)
            if (! exp_equiv_p (XVECEXP (x, i, j), XVECEXP (y, i, j),
            if (! exp_equiv_p (XVECEXP (x, i, j), XVECEXP (y, i, j),
                                validate, for_gcse))
                                validate, for_gcse))
              return 0;
              return 0;
          break;
          break;
 
 
        case 's':
        case 's':
          if (strcmp (XSTR (x, i), XSTR (y, i)))
          if (strcmp (XSTR (x, i), XSTR (y, i)))
            return 0;
            return 0;
          break;
          break;
 
 
        case 'i':
        case 'i':
          if (XINT (x, i) != XINT (y, i))
          if (XINT (x, i) != XINT (y, i))
            return 0;
            return 0;
          break;
          break;
 
 
        case 'w':
        case 'w':
          if (XWINT (x, i) != XWINT (y, i))
          if (XWINT (x, i) != XWINT (y, i))
            return 0;
            return 0;
          break;
          break;
 
 
        case '0':
        case '0':
        case 't':
        case 't':
          break;
          break;
 
 
        default:
        default:
          gcc_unreachable ();
          gcc_unreachable ();
        }
        }
    }
    }
 
 
  return 1;
  return 1;
}
}


/* Return 1 if X has a value that can vary even between two
/* Return 1 if X has a value that can vary even between two
   executions of the program.  0 means X can be compared reliably
   executions of the program.  0 means X can be compared reliably
   against certain constants or near-constants.  */
   against certain constants or near-constants.  */
 
 
static int
static int
cse_rtx_varies_p (rtx x, int from_alias)
cse_rtx_varies_p (rtx x, int from_alias)
{
{
  /* We need not check for X and the equivalence class being of the same
  /* We need not check for X and the equivalence class being of the same
     mode because if X is equivalent to a constant in some mode, it
     mode because if X is equivalent to a constant in some mode, it
     doesn't vary in any mode.  */
     doesn't vary in any mode.  */
 
 
  if (REG_P (x)
  if (REG_P (x)
      && REGNO_QTY_VALID_P (REGNO (x)))
      && REGNO_QTY_VALID_P (REGNO (x)))
    {
    {
      int x_q = REG_QTY (REGNO (x));
      int x_q = REG_QTY (REGNO (x));
      struct qty_table_elem *x_ent = &qty_table[x_q];
      struct qty_table_elem *x_ent = &qty_table[x_q];
 
 
      if (GET_MODE (x) == x_ent->mode
      if (GET_MODE (x) == x_ent->mode
          && x_ent->const_rtx != NULL_RTX)
          && x_ent->const_rtx != NULL_RTX)
        return 0;
        return 0;
    }
    }
 
 
  if (GET_CODE (x) == PLUS
  if (GET_CODE (x) == PLUS
      && GET_CODE (XEXP (x, 1)) == CONST_INT
      && GET_CODE (XEXP (x, 1)) == CONST_INT
      && REG_P (XEXP (x, 0))
      && REG_P (XEXP (x, 0))
      && REGNO_QTY_VALID_P (REGNO (XEXP (x, 0))))
      && REGNO_QTY_VALID_P (REGNO (XEXP (x, 0))))
    {
    {
      int x0_q = REG_QTY (REGNO (XEXP (x, 0)));
      int x0_q = REG_QTY (REGNO (XEXP (x, 0)));
      struct qty_table_elem *x0_ent = &qty_table[x0_q];
      struct qty_table_elem *x0_ent = &qty_table[x0_q];
 
 
      if ((GET_MODE (XEXP (x, 0)) == x0_ent->mode)
      if ((GET_MODE (XEXP (x, 0)) == x0_ent->mode)
          && x0_ent->const_rtx != NULL_RTX)
          && x0_ent->const_rtx != NULL_RTX)
        return 0;
        return 0;
    }
    }
 
 
  /* This can happen as the result of virtual register instantiation, if
  /* This can happen as the result of virtual register instantiation, if
     the initial constant is too large to be a valid address.  This gives
     the initial constant is too large to be a valid address.  This gives
     us a three instruction sequence, load large offset into a register,
     us a three instruction sequence, load large offset into a register,
     load fp minus a constant into a register, then a MEM which is the
     load fp minus a constant into a register, then a MEM which is the
     sum of the two `constant' registers.  */
     sum of the two `constant' registers.  */
  if (GET_CODE (x) == PLUS
  if (GET_CODE (x) == PLUS
      && REG_P (XEXP (x, 0))
      && REG_P (XEXP (x, 0))
      && REG_P (XEXP (x, 1))
      && REG_P (XEXP (x, 1))
      && REGNO_QTY_VALID_P (REGNO (XEXP (x, 0)))
      && REGNO_QTY_VALID_P (REGNO (XEXP (x, 0)))
      && REGNO_QTY_VALID_P (REGNO (XEXP (x, 1))))
      && REGNO_QTY_VALID_P (REGNO (XEXP (x, 1))))
    {
    {
      int x0_q = REG_QTY (REGNO (XEXP (x, 0)));
      int x0_q = REG_QTY (REGNO (XEXP (x, 0)));
      int x1_q = REG_QTY (REGNO (XEXP (x, 1)));
      int x1_q = REG_QTY (REGNO (XEXP (x, 1)));
      struct qty_table_elem *x0_ent = &qty_table[x0_q];
      struct qty_table_elem *x0_ent = &qty_table[x0_q];
      struct qty_table_elem *x1_ent = &qty_table[x1_q];
      struct qty_table_elem *x1_ent = &qty_table[x1_q];
 
 
      if ((GET_MODE (XEXP (x, 0)) == x0_ent->mode)
      if ((GET_MODE (XEXP (x, 0)) == x0_ent->mode)
          && x0_ent->const_rtx != NULL_RTX
          && x0_ent->const_rtx != NULL_RTX
          && (GET_MODE (XEXP (x, 1)) == x1_ent->mode)
          && (GET_MODE (XEXP (x, 1)) == x1_ent->mode)
          && x1_ent->const_rtx != NULL_RTX)
          && x1_ent->const_rtx != NULL_RTX)
        return 0;
        return 0;
    }
    }
 
 
  return rtx_varies_p (x, from_alias);
  return rtx_varies_p (x, from_alias);
}
}


/* Subroutine of canon_reg.  Pass *XLOC through canon_reg, and validate
/* Subroutine of canon_reg.  Pass *XLOC through canon_reg, and validate
   the result if necessary.  INSN is as for canon_reg.  */
   the result if necessary.  INSN is as for canon_reg.  */
 
 
static void
static void
validate_canon_reg (rtx *xloc, rtx insn)
validate_canon_reg (rtx *xloc, rtx insn)
{
{
  rtx new = canon_reg (*xloc, insn);
  rtx new = canon_reg (*xloc, insn);
 
 
  /* If replacing pseudo with hard reg or vice versa, ensure the
  /* If replacing pseudo with hard reg or vice versa, ensure the
     insn remains valid.  Likewise if the insn has MATCH_DUPs.  */
     insn remains valid.  Likewise if the insn has MATCH_DUPs.  */
  if (insn != 0 && new != 0)
  if (insn != 0 && new != 0)
    validate_change (insn, xloc, new, 1);
    validate_change (insn, xloc, new, 1);
  else
  else
    *xloc = new;
    *xloc = new;
}
}
 
 
/* Canonicalize an expression:
/* Canonicalize an expression:
   replace each register reference inside it
   replace each register reference inside it
   with the "oldest" equivalent register.
   with the "oldest" equivalent register.
 
 
   If INSN is nonzero validate_change is used to ensure that INSN remains valid
   If INSN is nonzero validate_change is used to ensure that INSN remains valid
   after we make our substitution.  The calls are made with IN_GROUP nonzero
   after we make our substitution.  The calls are made with IN_GROUP nonzero
   so apply_change_group must be called upon the outermost return from this
   so apply_change_group must be called upon the outermost return from this
   function (unless INSN is zero).  The result of apply_change_group can
   function (unless INSN is zero).  The result of apply_change_group can
   generally be discarded since the changes we are making are optional.  */
   generally be discarded since the changes we are making are optional.  */
 
 
static rtx
static rtx
canon_reg (rtx x, rtx insn)
canon_reg (rtx x, rtx insn)
{
{
  int i;
  int i;
  enum rtx_code code;
  enum rtx_code code;
  const char *fmt;
  const char *fmt;
 
 
  if (x == 0)
  if (x == 0)
    return x;
    return x;
 
 
  code = GET_CODE (x);
  code = GET_CODE (x);
  switch (code)
  switch (code)
    {
    {
    case PC:
    case PC:
    case CC0:
    case CC0:
    case CONST:
    case CONST:
    case CONST_INT:
    case CONST_INT:
    case CONST_DOUBLE:
    case CONST_DOUBLE:
    case CONST_VECTOR:
    case CONST_VECTOR:
    case SYMBOL_REF:
    case SYMBOL_REF:
    case LABEL_REF:
    case LABEL_REF:
    case ADDR_VEC:
    case ADDR_VEC:
    case ADDR_DIFF_VEC:
    case ADDR_DIFF_VEC:
      return x;
      return x;
 
 
    case REG:
    case REG:
      {
      {
        int first;
        int first;
        int q;
        int q;
        struct qty_table_elem *ent;
        struct qty_table_elem *ent;
 
 
        /* Never replace a hard reg, because hard regs can appear
        /* Never replace a hard reg, because hard regs can appear
           in more than one machine mode, and we must preserve the mode
           in more than one machine mode, and we must preserve the mode
           of each occurrence.  Also, some hard regs appear in
           of each occurrence.  Also, some hard regs appear in
           MEMs that are shared and mustn't be altered.  Don't try to
           MEMs that are shared and mustn't be altered.  Don't try to
           replace any reg that maps to a reg of class NO_REGS.  */
           replace any reg that maps to a reg of class NO_REGS.  */
        if (REGNO (x) < FIRST_PSEUDO_REGISTER
        if (REGNO (x) < FIRST_PSEUDO_REGISTER
            || ! REGNO_QTY_VALID_P (REGNO (x)))
            || ! REGNO_QTY_VALID_P (REGNO (x)))
          return x;
          return x;
 
 
        q = REG_QTY (REGNO (x));
        q = REG_QTY (REGNO (x));
        ent = &qty_table[q];
        ent = &qty_table[q];
        first = ent->first_reg;
        first = ent->first_reg;
        return (first >= FIRST_PSEUDO_REGISTER ? regno_reg_rtx[first]
        return (first >= FIRST_PSEUDO_REGISTER ? regno_reg_rtx[first]
                : REGNO_REG_CLASS (first) == NO_REGS ? x
                : REGNO_REG_CLASS (first) == NO_REGS ? x
                : gen_rtx_REG (ent->mode, first));
                : gen_rtx_REG (ent->mode, first));
      }
      }
 
 
    default:
    default:
      break;
      break;
    }
    }
 
 
  fmt = GET_RTX_FORMAT (code);
  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
    {
      int j;
      int j;
 
 
      if (fmt[i] == 'e')
      if (fmt[i] == 'e')
        validate_canon_reg (&XEXP (x, i), insn);
        validate_canon_reg (&XEXP (x, i), insn);
      else if (fmt[i] == 'E')
      else if (fmt[i] == 'E')
        for (j = 0; j < XVECLEN (x, i); j++)
        for (j = 0; j < XVECLEN (x, i); j++)
          validate_canon_reg (&XVECEXP (x, i, j), insn);
          validate_canon_reg (&XVECEXP (x, i, j), insn);
    }
    }
 
 
  return x;
  return x;
}
}


/* LOC is a location within INSN that is an operand address (the contents of
/* LOC is a location within INSN that is an operand address (the contents of
   a MEM).  Find the best equivalent address to use that is valid for this
   a MEM).  Find the best equivalent address to use that is valid for this
   insn.
   insn.
 
 
   On most CISC machines, complicated address modes are costly, and rtx_cost
   On most CISC machines, complicated address modes are costly, and rtx_cost
   is a good approximation for that cost.  However, most RISC machines have
   is a good approximation for that cost.  However, most RISC machines have
   only a few (usually only one) memory reference formats.  If an address is
   only a few (usually only one) memory reference formats.  If an address is
   valid at all, it is often just as cheap as any other address.  Hence, for
   valid at all, it is often just as cheap as any other address.  Hence, for
   RISC machines, we use `address_cost' to compare the costs of various
   RISC machines, we use `address_cost' to compare the costs of various
   addresses.  For two addresses of equal cost, choose the one with the
   addresses.  For two addresses of equal cost, choose the one with the
   highest `rtx_cost' value as that has the potential of eliminating the
   highest `rtx_cost' value as that has the potential of eliminating the
   most insns.  For equal costs, we choose the first in the equivalence
   most insns.  For equal costs, we choose the first in the equivalence
   class.  Note that we ignore the fact that pseudo registers are cheaper than
   class.  Note that we ignore the fact that pseudo registers are cheaper than
   hard registers here because we would also prefer the pseudo registers.  */
   hard registers here because we would also prefer the pseudo registers.  */
 
 
static void
static void
find_best_addr (rtx insn, rtx *loc, enum machine_mode mode)
find_best_addr (rtx insn, rtx *loc, enum machine_mode mode)
{
{
  struct table_elt *elt;
  struct table_elt *elt;
  rtx addr = *loc;
  rtx addr = *loc;
  struct table_elt *p;
  struct table_elt *p;
  int found_better = 1;
  int found_better = 1;
  int save_do_not_record = do_not_record;
  int save_do_not_record = do_not_record;
  int save_hash_arg_in_memory = hash_arg_in_memory;
  int save_hash_arg_in_memory = hash_arg_in_memory;
  int addr_volatile;
  int addr_volatile;
  int regno;
  int regno;
  unsigned hash;
  unsigned hash;
 
 
  /* Do not try to replace constant addresses or addresses of local and
  /* Do not try to replace constant addresses or addresses of local and
     argument slots.  These MEM expressions are made only once and inserted
     argument slots.  These MEM expressions are made only once and inserted
     in many instructions, as well as being used to control symbol table
     in many instructions, as well as being used to control symbol table
     output.  It is not safe to clobber them.
     output.  It is not safe to clobber them.
 
 
     There are some uncommon cases where the address is already in a register
     There are some uncommon cases where the address is already in a register
     for some reason, but we cannot take advantage of that because we have
     for some reason, but we cannot take advantage of that because we have
     no easy way to unshare the MEM.  In addition, looking up all stack
     no easy way to unshare the MEM.  In addition, looking up all stack
     addresses is costly.  */
     addresses is costly.  */
  if ((GET_CODE (addr) == PLUS
  if ((GET_CODE (addr) == PLUS
       && REG_P (XEXP (addr, 0))
       && REG_P (XEXP (addr, 0))
       && GET_CODE (XEXP (addr, 1)) == CONST_INT
       && GET_CODE (XEXP (addr, 1)) == CONST_INT
       && (regno = REGNO (XEXP (addr, 0)),
       && (regno = REGNO (XEXP (addr, 0)),
           regno == FRAME_POINTER_REGNUM || regno == HARD_FRAME_POINTER_REGNUM
           regno == FRAME_POINTER_REGNUM || regno == HARD_FRAME_POINTER_REGNUM
           || regno == ARG_POINTER_REGNUM))
           || regno == ARG_POINTER_REGNUM))
      || (REG_P (addr)
      || (REG_P (addr)
          && (regno = REGNO (addr), regno == FRAME_POINTER_REGNUM
          && (regno = REGNO (addr), regno == FRAME_POINTER_REGNUM
              || regno == HARD_FRAME_POINTER_REGNUM
              || regno == HARD_FRAME_POINTER_REGNUM
              || regno == ARG_POINTER_REGNUM))
              || regno == ARG_POINTER_REGNUM))
      || CONSTANT_ADDRESS_P (addr))
      || CONSTANT_ADDRESS_P (addr))
    return;
    return;
 
 
  /* If this address is not simply a register, try to fold it.  This will
  /* If this address is not simply a register, try to fold it.  This will
     sometimes simplify the expression.  Many simplifications
     sometimes simplify the expression.  Many simplifications
     will not be valid, but some, usually applying the associative rule, will
     will not be valid, but some, usually applying the associative rule, will
     be valid and produce better code.  */
     be valid and produce better code.  */
  if (!REG_P (addr))
  if (!REG_P (addr))
    {
    {
      rtx folded = canon_for_address (fold_rtx (addr, NULL_RTX));
      rtx folded = canon_for_address (fold_rtx (addr, NULL_RTX));
 
 
      if (folded != addr)
      if (folded != addr)
        {
        {
          int addr_folded_cost = address_cost (folded, mode);
          int addr_folded_cost = address_cost (folded, mode);
          int addr_cost = address_cost (addr, mode);
          int addr_cost = address_cost (addr, mode);
 
 
          if ((addr_folded_cost < addr_cost
          if ((addr_folded_cost < addr_cost
               || (addr_folded_cost == addr_cost
               || (addr_folded_cost == addr_cost
                   /* ??? The rtx_cost comparison is left over from an older
                   /* ??? The rtx_cost comparison is left over from an older
                      version of this code.  It is probably no longer helpful.*/
                      version of this code.  It is probably no longer helpful.*/
                   && (rtx_cost (folded, MEM) > rtx_cost (addr, MEM)
                   && (rtx_cost (folded, MEM) > rtx_cost (addr, MEM)
                       || approx_reg_cost (folded) < approx_reg_cost (addr))))
                       || approx_reg_cost (folded) < approx_reg_cost (addr))))
              && validate_change (insn, loc, folded, 0))
              && validate_change (insn, loc, folded, 0))
            addr = folded;
            addr = folded;
        }
        }
    }
    }
 
 
  /* If this address is not in the hash table, we can't look for equivalences
  /* If this address is not in the hash table, we can't look for equivalences
     of the whole address.  Also, ignore if volatile.  */
     of the whole address.  Also, ignore if volatile.  */
 
 
  do_not_record = 0;
  do_not_record = 0;
  hash = HASH (addr, Pmode);
  hash = HASH (addr, Pmode);
  addr_volatile = do_not_record;
  addr_volatile = do_not_record;
  do_not_record = save_do_not_record;
  do_not_record = save_do_not_record;
  hash_arg_in_memory = save_hash_arg_in_memory;
  hash_arg_in_memory = save_hash_arg_in_memory;
 
 
  if (addr_volatile)
  if (addr_volatile)
    return;
    return;
 
 
  elt = lookup (addr, hash, Pmode);
  elt = lookup (addr, hash, Pmode);
 
 
  if (elt)
  if (elt)
    {
    {
      /* We need to find the best (under the criteria documented above) entry
      /* We need to find the best (under the criteria documented above) entry
         in the class that is valid.  We use the `flag' field to indicate
         in the class that is valid.  We use the `flag' field to indicate
         choices that were invalid and iterate until we can't find a better
         choices that were invalid and iterate until we can't find a better
         one that hasn't already been tried.  */
         one that hasn't already been tried.  */
 
 
      for (p = elt->first_same_value; p; p = p->next_same_value)
      for (p = elt->first_same_value; p; p = p->next_same_value)
        p->flag = 0;
        p->flag = 0;
 
 
      while (found_better)
      while (found_better)
        {
        {
          int best_addr_cost = address_cost (*loc, mode);
          int best_addr_cost = address_cost (*loc, mode);
          int best_rtx_cost = (elt->cost + 1) >> 1;
          int best_rtx_cost = (elt->cost + 1) >> 1;
          int exp_cost;
          int exp_cost;
          struct table_elt *best_elt = elt;
          struct table_elt *best_elt = elt;
 
 
          found_better = 0;
          found_better = 0;
          for (p = elt->first_same_value; p; p = p->next_same_value)
          for (p = elt->first_same_value; p; p = p->next_same_value)
            if (! p->flag)
            if (! p->flag)
              {
              {
                if ((REG_P (p->exp)
                if ((REG_P (p->exp)
                     || exp_equiv_p (p->exp, p->exp, 1, false))
                     || exp_equiv_p (p->exp, p->exp, 1, false))
                    && ((exp_cost = address_cost (p->exp, mode)) < best_addr_cost
                    && ((exp_cost = address_cost (p->exp, mode)) < best_addr_cost
                        || (exp_cost == best_addr_cost
                        || (exp_cost == best_addr_cost
                            && ((p->cost + 1) >> 1) > best_rtx_cost)))
                            && ((p->cost + 1) >> 1) > best_rtx_cost)))
                  {
                  {
                    found_better = 1;
                    found_better = 1;
                    best_addr_cost = exp_cost;
                    best_addr_cost = exp_cost;
                    best_rtx_cost = (p->cost + 1) >> 1;
                    best_rtx_cost = (p->cost + 1) >> 1;
                    best_elt = p;
                    best_elt = p;
                  }
                  }
              }
              }
 
 
          if (found_better)
          if (found_better)
            {
            {
              if (validate_change (insn, loc,
              if (validate_change (insn, loc,
                                   canon_reg (copy_rtx (best_elt->exp),
                                   canon_reg (copy_rtx (best_elt->exp),
                                              NULL_RTX), 0))
                                              NULL_RTX), 0))
                return;
                return;
              else
              else
                best_elt->flag = 1;
                best_elt->flag = 1;
            }
            }
        }
        }
    }
    }
 
 
  /* If the address is a binary operation with the first operand a register
  /* If the address is a binary operation with the first operand a register
     and the second a constant, do the same as above, but looking for
     and the second a constant, do the same as above, but looking for
     equivalences of the register.  Then try to simplify before checking for
     equivalences of the register.  Then try to simplify before checking for
     the best address to use.  This catches a few cases:  First is when we
     the best address to use.  This catches a few cases:  First is when we
     have REG+const and the register is another REG+const.  We can often merge
     have REG+const and the register is another REG+const.  We can often merge
     the constants and eliminate one insn and one register.  It may also be
     the constants and eliminate one insn and one register.  It may also be
     that a machine has a cheap REG+REG+const.  Finally, this improves the
     that a machine has a cheap REG+REG+const.  Finally, this improves the
     code on the Alpha for unaligned byte stores.  */
     code on the Alpha for unaligned byte stores.  */
 
 
  if (flag_expensive_optimizations
  if (flag_expensive_optimizations
      && ARITHMETIC_P (*loc)
      && ARITHMETIC_P (*loc)
      && REG_P (XEXP (*loc, 0)))
      && REG_P (XEXP (*loc, 0)))
    {
    {
      rtx op1 = XEXP (*loc, 1);
      rtx op1 = XEXP (*loc, 1);
 
 
      do_not_record = 0;
      do_not_record = 0;
      hash = HASH (XEXP (*loc, 0), Pmode);
      hash = HASH (XEXP (*loc, 0), Pmode);
      do_not_record = save_do_not_record;
      do_not_record = save_do_not_record;
      hash_arg_in_memory = save_hash_arg_in_memory;
      hash_arg_in_memory = save_hash_arg_in_memory;
 
 
      elt = lookup (XEXP (*loc, 0), hash, Pmode);
      elt = lookup (XEXP (*loc, 0), hash, Pmode);
      if (elt == 0)
      if (elt == 0)
        return;
        return;
 
 
      /* We need to find the best (under the criteria documented above) entry
      /* We need to find the best (under the criteria documented above) entry
         in the class that is valid.  We use the `flag' field to indicate
         in the class that is valid.  We use the `flag' field to indicate
         choices that were invalid and iterate until we can't find a better
         choices that were invalid and iterate until we can't find a better
         one that hasn't already been tried.  */
         one that hasn't already been tried.  */
 
 
      for (p = elt->first_same_value; p; p = p->next_same_value)
      for (p = elt->first_same_value; p; p = p->next_same_value)
        p->flag = 0;
        p->flag = 0;
 
 
      while (found_better)
      while (found_better)
        {
        {
          int best_addr_cost = address_cost (*loc, mode);
          int best_addr_cost = address_cost (*loc, mode);
          int best_rtx_cost = (COST (*loc) + 1) >> 1;
          int best_rtx_cost = (COST (*loc) + 1) >> 1;
          struct table_elt *best_elt = elt;
          struct table_elt *best_elt = elt;
          rtx best_rtx = *loc;
          rtx best_rtx = *loc;
          int count;
          int count;
 
 
          /* This is at worst case an O(n^2) algorithm, so limit our search
          /* This is at worst case an O(n^2) algorithm, so limit our search
             to the first 32 elements on the list.  This avoids trouble
             to the first 32 elements on the list.  This avoids trouble
             compiling code with very long basic blocks that can easily
             compiling code with very long basic blocks that can easily
             call simplify_gen_binary so many times that we run out of
             call simplify_gen_binary so many times that we run out of
             memory.  */
             memory.  */
 
 
          found_better = 0;
          found_better = 0;
          for (p = elt->first_same_value, count = 0;
          for (p = elt->first_same_value, count = 0;
               p && count < 32;
               p && count < 32;
               p = p->next_same_value, count++)
               p = p->next_same_value, count++)
            if (! p->flag
            if (! p->flag
                && (REG_P (p->exp)
                && (REG_P (p->exp)
                    || (GET_CODE (p->exp) != EXPR_LIST
                    || (GET_CODE (p->exp) != EXPR_LIST
                        && exp_equiv_p (p->exp, p->exp, 1, false))))
                        && exp_equiv_p (p->exp, p->exp, 1, false))))
 
 
              {
              {
                rtx new = simplify_gen_binary (GET_CODE (*loc), Pmode,
                rtx new = simplify_gen_binary (GET_CODE (*loc), Pmode,
                                               p->exp, op1);
                                               p->exp, op1);
                int new_cost;
                int new_cost;
 
 
                /* Get the canonical version of the address so we can accept
                /* Get the canonical version of the address so we can accept
                   more.  */
                   more.  */
                new = canon_for_address (new);
                new = canon_for_address (new);
 
 
                new_cost = address_cost (new, mode);
                new_cost = address_cost (new, mode);
 
 
                if (new_cost < best_addr_cost
                if (new_cost < best_addr_cost
                    || (new_cost == best_addr_cost
                    || (new_cost == best_addr_cost
                        && (COST (new) + 1) >> 1 > best_rtx_cost))
                        && (COST (new) + 1) >> 1 > best_rtx_cost))
                  {
                  {
                    found_better = 1;
                    found_better = 1;
                    best_addr_cost = new_cost;
                    best_addr_cost = new_cost;
                    best_rtx_cost = (COST (new) + 1) >> 1;
                    best_rtx_cost = (COST (new) + 1) >> 1;
                    best_elt = p;
                    best_elt = p;
                    best_rtx = new;
                    best_rtx = new;
                  }
                  }
              }
              }
 
 
          if (found_better)
          if (found_better)
            {
            {
              if (validate_change (insn, loc,
              if (validate_change (insn, loc,
                                   canon_reg (copy_rtx (best_rtx),
                                   canon_reg (copy_rtx (best_rtx),
                                              NULL_RTX), 0))
                                              NULL_RTX), 0))
                return;
                return;
              else
              else
                best_elt->flag = 1;
                best_elt->flag = 1;
            }
            }
        }
        }
    }
    }
}
}


/* Given an operation (CODE, *PARG1, *PARG2), where code is a comparison
/* Given an operation (CODE, *PARG1, *PARG2), where code is a comparison
   operation (EQ, NE, GT, etc.), follow it back through the hash table and
   operation (EQ, NE, GT, etc.), follow it back through the hash table and
   what values are being compared.
   what values are being compared.
 
 
   *PARG1 and *PARG2 are updated to contain the rtx representing the values
   *PARG1 and *PARG2 are updated to contain the rtx representing the values
   actually being compared.  For example, if *PARG1 was (cc0) and *PARG2
   actually being compared.  For example, if *PARG1 was (cc0) and *PARG2
   was (const_int 0), *PARG1 and *PARG2 will be set to the objects that were
   was (const_int 0), *PARG1 and *PARG2 will be set to the objects that were
   compared to produce cc0.
   compared to produce cc0.
 
 
   The return value is the comparison operator and is either the code of
   The return value is the comparison operator and is either the code of
   A or the code corresponding to the inverse of the comparison.  */
   A or the code corresponding to the inverse of the comparison.  */
 
 
static enum rtx_code
static enum rtx_code
find_comparison_args (enum rtx_code code, rtx *parg1, rtx *parg2,
find_comparison_args (enum rtx_code code, rtx *parg1, rtx *parg2,
                      enum machine_mode *pmode1, enum machine_mode *pmode2)
                      enum machine_mode *pmode1, enum machine_mode *pmode2)
{
{
  rtx arg1, arg2;
  rtx arg1, arg2;
 
 
  arg1 = *parg1, arg2 = *parg2;
  arg1 = *parg1, arg2 = *parg2;
 
 
  /* If ARG2 is const0_rtx, see what ARG1 is equivalent to.  */
  /* If ARG2 is const0_rtx, see what ARG1 is equivalent to.  */
 
 
  while (arg2 == CONST0_RTX (GET_MODE (arg1)))
  while (arg2 == CONST0_RTX (GET_MODE (arg1)))
    {
    {
      /* Set nonzero when we find something of interest.  */
      /* Set nonzero when we find something of interest.  */
      rtx x = 0;
      rtx x = 0;
      int reverse_code = 0;
      int reverse_code = 0;
      struct table_elt *p = 0;
      struct table_elt *p = 0;
 
 
      /* If arg1 is a COMPARE, extract the comparison arguments from it.
      /* If arg1 is a COMPARE, extract the comparison arguments from it.
         On machines with CC0, this is the only case that can occur, since
         On machines with CC0, this is the only case that can occur, since
         fold_rtx will return the COMPARE or item being compared with zero
         fold_rtx will return the COMPARE or item being compared with zero
         when given CC0.  */
         when given CC0.  */
 
 
      if (GET_CODE (arg1) == COMPARE && arg2 == const0_rtx)
      if (GET_CODE (arg1) == COMPARE && arg2 == const0_rtx)
        x = arg1;
        x = arg1;
 
 
      /* If ARG1 is a comparison operator and CODE is testing for
      /* If ARG1 is a comparison operator and CODE is testing for
         STORE_FLAG_VALUE, get the inner arguments.  */
         STORE_FLAG_VALUE, get the inner arguments.  */
 
 
      else if (COMPARISON_P (arg1))
      else if (COMPARISON_P (arg1))
        {
        {
#ifdef FLOAT_STORE_FLAG_VALUE
#ifdef FLOAT_STORE_FLAG_VALUE
          REAL_VALUE_TYPE fsfv;
          REAL_VALUE_TYPE fsfv;
#endif
#endif
 
 
          if (code == NE
          if (code == NE
              || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_INT
              || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_INT
                  && code == LT && STORE_FLAG_VALUE == -1)
                  && code == LT && STORE_FLAG_VALUE == -1)
#ifdef FLOAT_STORE_FLAG_VALUE
#ifdef FLOAT_STORE_FLAG_VALUE
              || (SCALAR_FLOAT_MODE_P (GET_MODE (arg1))
              || (SCALAR_FLOAT_MODE_P (GET_MODE (arg1))
                  && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)),
                  && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)),
                      REAL_VALUE_NEGATIVE (fsfv)))
                      REAL_VALUE_NEGATIVE (fsfv)))
#endif
#endif
              )
              )
            x = arg1;
            x = arg1;
          else if (code == EQ
          else if (code == EQ
                   || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_INT
                   || (GET_MODE_CLASS (GET_MODE (arg1)) == MODE_INT
                       && code == GE && STORE_FLAG_VALUE == -1)
                       && code == GE && STORE_FLAG_VALUE == -1)
#ifdef FLOAT_STORE_FLAG_VALUE
#ifdef FLOAT_STORE_FLAG_VALUE
                   || (SCALAR_FLOAT_MODE_P (GET_MODE (arg1))
                   || (SCALAR_FLOAT_MODE_P (GET_MODE (arg1))
                       && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)),
                       && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)),
                           REAL_VALUE_NEGATIVE (fsfv)))
                           REAL_VALUE_NEGATIVE (fsfv)))
#endif
#endif
                   )
                   )
            x = arg1, reverse_code = 1;
            x = arg1, reverse_code = 1;
        }
        }
 
 
      /* ??? We could also check for
      /* ??? We could also check for
 
 
         (ne (and (eq (...) (const_int 1))) (const_int 0))
         (ne (and (eq (...) (const_int 1))) (const_int 0))
 
 
         and related forms, but let's wait until we see them occurring.  */
         and related forms, but let's wait until we see them occurring.  */
 
 
      if (x == 0)
      if (x == 0)
        /* Look up ARG1 in the hash table and see if it has an equivalence
        /* Look up ARG1 in the hash table and see if it has an equivalence
           that lets us see what is being compared.  */
           that lets us see what is being compared.  */
        p = lookup (arg1, SAFE_HASH (arg1, GET_MODE (arg1)), GET_MODE (arg1));
        p = lookup (arg1, SAFE_HASH (arg1, GET_MODE (arg1)), GET_MODE (arg1));
      if (p)
      if (p)
        {
        {
          p = p->first_same_value;
          p = p->first_same_value;
 
 
          /* If what we compare is already known to be constant, that is as
          /* If what we compare is already known to be constant, that is as
             good as it gets.
             good as it gets.
             We need to break the loop in this case, because otherwise we
             We need to break the loop in this case, because otherwise we
             can have an infinite loop when looking at a reg that is known
             can have an infinite loop when looking at a reg that is known
             to be a constant which is the same as a comparison of a reg
             to be a constant which is the same as a comparison of a reg
             against zero which appears later in the insn stream, which in
             against zero which appears later in the insn stream, which in
             turn is constant and the same as the comparison of the first reg
             turn is constant and the same as the comparison of the first reg
             against zero...  */
             against zero...  */
          if (p->is_const)
          if (p->is_const)
            break;
            break;
        }
        }
 
 
      for (; p; p = p->next_same_value)
      for (; p; p = p->next_same_value)
        {
        {
          enum machine_mode inner_mode = GET_MODE (p->exp);
          enum machine_mode inner_mode = GET_MODE (p->exp);
#ifdef FLOAT_STORE_FLAG_VALUE
#ifdef FLOAT_STORE_FLAG_VALUE
          REAL_VALUE_TYPE fsfv;
          REAL_VALUE_TYPE fsfv;
#endif
#endif
 
 
          /* If the entry isn't valid, skip it.  */
          /* If the entry isn't valid, skip it.  */
          if (! exp_equiv_p (p->exp, p->exp, 1, false))
          if (! exp_equiv_p (p->exp, p->exp, 1, false))
            continue;
            continue;
 
 
          if (GET_CODE (p->exp) == COMPARE
          if (GET_CODE (p->exp) == COMPARE
              /* Another possibility is that this machine has a compare insn
              /* Another possibility is that this machine has a compare insn
                 that includes the comparison code.  In that case, ARG1 would
                 that includes the comparison code.  In that case, ARG1 would
                 be equivalent to a comparison operation that would set ARG1 to
                 be equivalent to a comparison operation that would set ARG1 to
                 either STORE_FLAG_VALUE or zero.  If this is an NE operation,
                 either STORE_FLAG_VALUE or zero.  If this is an NE operation,
                 ORIG_CODE is the actual comparison being done; if it is an EQ,
                 ORIG_CODE is the actual comparison being done; if it is an EQ,
                 we must reverse ORIG_CODE.  On machine with a negative value
                 we must reverse ORIG_CODE.  On machine with a negative value
                 for STORE_FLAG_VALUE, also look at LT and GE operations.  */
                 for STORE_FLAG_VALUE, also look at LT and GE operations.  */
              || ((code == NE
              || ((code == NE
                   || (code == LT
                   || (code == LT
                       && GET_MODE_CLASS (inner_mode) == MODE_INT
                       && GET_MODE_CLASS (inner_mode) == MODE_INT
                       && (GET_MODE_BITSIZE (inner_mode)
                       && (GET_MODE_BITSIZE (inner_mode)
                           <= HOST_BITS_PER_WIDE_INT)
                           <= HOST_BITS_PER_WIDE_INT)
                       && (STORE_FLAG_VALUE
                       && (STORE_FLAG_VALUE
                           & ((HOST_WIDE_INT) 1
                           & ((HOST_WIDE_INT) 1
                              << (GET_MODE_BITSIZE (inner_mode) - 1))))
                              << (GET_MODE_BITSIZE (inner_mode) - 1))))
#ifdef FLOAT_STORE_FLAG_VALUE
#ifdef FLOAT_STORE_FLAG_VALUE
                   || (code == LT
                   || (code == LT
                       && SCALAR_FLOAT_MODE_P (inner_mode)
                       && SCALAR_FLOAT_MODE_P (inner_mode)
                       && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)),
                       && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)),
                           REAL_VALUE_NEGATIVE (fsfv)))
                           REAL_VALUE_NEGATIVE (fsfv)))
#endif
#endif
                   )
                   )
                  && COMPARISON_P (p->exp)))
                  && COMPARISON_P (p->exp)))
            {
            {
              x = p->exp;
              x = p->exp;
              break;
              break;
            }
            }
          else if ((code == EQ
          else if ((code == EQ
                    || (code == GE
                    || (code == GE
                        && GET_MODE_CLASS (inner_mode) == MODE_INT
                        && GET_MODE_CLASS (inner_mode) == MODE_INT
                        && (GET_MODE_BITSIZE (inner_mode)
                        && (GET_MODE_BITSIZE (inner_mode)
                            <= HOST_BITS_PER_WIDE_INT)
                            <= HOST_BITS_PER_WIDE_INT)
                        && (STORE_FLAG_VALUE
                        && (STORE_FLAG_VALUE
                            & ((HOST_WIDE_INT) 1
                            & ((HOST_WIDE_INT) 1
                               << (GET_MODE_BITSIZE (inner_mode) - 1))))
                               << (GET_MODE_BITSIZE (inner_mode) - 1))))
#ifdef FLOAT_STORE_FLAG_VALUE
#ifdef FLOAT_STORE_FLAG_VALUE
                    || (code == GE
                    || (code == GE
                        && SCALAR_FLOAT_MODE_P (inner_mode)
                        && SCALAR_FLOAT_MODE_P (inner_mode)
                        && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)),
                        && (fsfv = FLOAT_STORE_FLAG_VALUE (GET_MODE (arg1)),
                            REAL_VALUE_NEGATIVE (fsfv)))
                            REAL_VALUE_NEGATIVE (fsfv)))
#endif
#endif
                    )
                    )
                   && COMPARISON_P (p->exp))
                   && COMPARISON_P (p->exp))
            {
            {
              reverse_code = 1;
              reverse_code = 1;
              x = p->exp;
              x = p->exp;
              break;
              break;
            }
            }
 
 
          /* If this non-trapping address, e.g. fp + constant, the
          /* If this non-trapping address, e.g. fp + constant, the
             equivalent is a better operand since it may let us predict
             equivalent is a better operand since it may let us predict
             the value of the comparison.  */
             the value of the comparison.  */
          else if (!rtx_addr_can_trap_p (p->exp))
          else if (!rtx_addr_can_trap_p (p->exp))
            {
            {
              arg1 = p->exp;
              arg1 = p->exp;
              continue;
              continue;
            }
            }
        }
        }
 
 
      /* If we didn't find a useful equivalence for ARG1, we are done.
      /* If we didn't find a useful equivalence for ARG1, we are done.
         Otherwise, set up for the next iteration.  */
         Otherwise, set up for the next iteration.  */
      if (x == 0)
      if (x == 0)
        break;
        break;
 
 
      /* If we need to reverse the comparison, make sure that that is
      /* If we need to reverse the comparison, make sure that that is
         possible -- we can't necessarily infer the value of GE from LT
         possible -- we can't necessarily infer the value of GE from LT
         with floating-point operands.  */
         with floating-point operands.  */
      if (reverse_code)
      if (reverse_code)
        {
        {
          enum rtx_code reversed = reversed_comparison_code (x, NULL_RTX);
          enum rtx_code reversed = reversed_comparison_code (x, NULL_RTX);
          if (reversed == UNKNOWN)
          if (reversed == UNKNOWN)
            break;
            break;
          else
          else
            code = reversed;
            code = reversed;
        }
        }
      else if (COMPARISON_P (x))
      else if (COMPARISON_P (x))
        code = GET_CODE (x);
        code = GET_CODE (x);
      arg1 = XEXP (x, 0), arg2 = XEXP (x, 1);
      arg1 = XEXP (x, 0), arg2 = XEXP (x, 1);
    }
    }
 
 
  /* Return our results.  Return the modes from before fold_rtx
  /* Return our results.  Return the modes from before fold_rtx
     because fold_rtx might produce const_int, and then it's too late.  */
     because fold_rtx might produce const_int, and then it's too late.  */
  *pmode1 = GET_MODE (arg1), *pmode2 = GET_MODE (arg2);
  *pmode1 = GET_MODE (arg1), *pmode2 = GET_MODE (arg2);
  *parg1 = fold_rtx (arg1, 0), *parg2 = fold_rtx (arg2, 0);
  *parg1 = fold_rtx (arg1, 0), *parg2 = fold_rtx (arg2, 0);
 
 
  return code;
  return code;
}
}


/* Fold SUBREG.  */
/* Fold SUBREG.  */
 
 
static rtx
static rtx
fold_rtx_subreg (rtx x, rtx insn)
fold_rtx_subreg (rtx x, rtx insn)
{
{
  enum machine_mode mode = GET_MODE (x);
  enum machine_mode mode = GET_MODE (x);
  rtx folded_arg0;
  rtx folded_arg0;
  rtx const_arg0;
  rtx const_arg0;
  rtx new;
  rtx new;
 
 
  /* See if we previously assigned a constant value to this SUBREG.  */
  /* See if we previously assigned a constant value to this SUBREG.  */
  if ((new = lookup_as_function (x, CONST_INT)) != 0
  if ((new = lookup_as_function (x, CONST_INT)) != 0
      || (new = lookup_as_function (x, CONST_DOUBLE)) != 0)
      || (new = lookup_as_function (x, CONST_DOUBLE)) != 0)
    return new;
    return new;
 
 
  /* If this is a paradoxical SUBREG, we have no idea what value the
  /* If this is a paradoxical SUBREG, we have no idea what value the
     extra bits would have.  However, if the operand is equivalent to
     extra bits would have.  However, if the operand is equivalent to
     a SUBREG whose operand is the same as our mode, and all the modes
     a SUBREG whose operand is the same as our mode, and all the modes
     are within a word, we can just use the inner operand because
     are within a word, we can just use the inner operand because
     these SUBREGs just say how to treat the register.
     these SUBREGs just say how to treat the register.
 
 
     Similarly if we find an integer constant.  */
     Similarly if we find an integer constant.  */
 
 
  if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
  if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
    {
    {
      enum machine_mode imode = GET_MODE (SUBREG_REG (x));
      enum machine_mode imode = GET_MODE (SUBREG_REG (x));
      struct table_elt *elt;
      struct table_elt *elt;
 
 
      if (GET_MODE_SIZE (mode) <= UNITS_PER_WORD
      if (GET_MODE_SIZE (mode) <= UNITS_PER_WORD
          && GET_MODE_SIZE (imode) <= UNITS_PER_WORD
          && GET_MODE_SIZE (imode) <= UNITS_PER_WORD
          && (elt = lookup (SUBREG_REG (x), HASH (SUBREG_REG (x), imode),
          && (elt = lookup (SUBREG_REG (x), HASH (SUBREG_REG (x), imode),
                            imode)) != 0)
                            imode)) != 0)
        for (elt = elt->first_same_value; elt; elt = elt->next_same_value)
        for (elt = elt->first_same_value; elt; elt = elt->next_same_value)
          {
          {
            if (CONSTANT_P (elt->exp)
            if (CONSTANT_P (elt->exp)
                && GET_MODE (elt->exp) == VOIDmode)
                && GET_MODE (elt->exp) == VOIDmode)
              return elt->exp;
              return elt->exp;
 
 
            if (GET_CODE (elt->exp) == SUBREG
            if (GET_CODE (elt->exp) == SUBREG
                && GET_MODE (SUBREG_REG (elt->exp)) == mode
                && GET_MODE (SUBREG_REG (elt->exp)) == mode
                && exp_equiv_p (elt->exp, elt->exp, 1, false))
                && exp_equiv_p (elt->exp, elt->exp, 1, false))
              return copy_rtx (SUBREG_REG (elt->exp));
              return copy_rtx (SUBREG_REG (elt->exp));
          }
          }
 
 
      return x;
      return x;
    }
    }
 
 
  /* Fold SUBREG_REG.  If it changed, see if we can simplify the
  /* Fold SUBREG_REG.  If it changed, see if we can simplify the
     SUBREG.  We might be able to if the SUBREG is extracting a single
     SUBREG.  We might be able to if the SUBREG is extracting a single
     word in an integral mode or extracting the low part.  */
     word in an integral mode or extracting the low part.  */
 
 
  folded_arg0 = fold_rtx (SUBREG_REG (x), insn);
  folded_arg0 = fold_rtx (SUBREG_REG (x), insn);
  const_arg0 = equiv_constant (folded_arg0);
  const_arg0 = equiv_constant (folded_arg0);
  if (const_arg0)
  if (const_arg0)
    folded_arg0 = const_arg0;
    folded_arg0 = const_arg0;
 
 
  if (folded_arg0 != SUBREG_REG (x))
  if (folded_arg0 != SUBREG_REG (x))
    {
    {
      new = simplify_subreg (mode, folded_arg0,
      new = simplify_subreg (mode, folded_arg0,
                             GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
                             GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
      if (new)
      if (new)
        return new;
        return new;
    }
    }
 
 
  if (REG_P (folded_arg0)
  if (REG_P (folded_arg0)
      && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (folded_arg0)))
      && GET_MODE_SIZE (mode) < GET_MODE_SIZE (GET_MODE (folded_arg0)))
    {
    {
      struct table_elt *elt;
      struct table_elt *elt;
 
 
      elt = lookup (folded_arg0,
      elt = lookup (folded_arg0,
                    HASH (folded_arg0, GET_MODE (folded_arg0)),
                    HASH (folded_arg0, GET_MODE (folded_arg0)),
                    GET_MODE (folded_arg0));
                    GET_MODE (folded_arg0));
 
 
      if (elt)
      if (elt)
        elt = elt->first_same_value;
        elt = elt->first_same_value;
 
 
      if (subreg_lowpart_p (x))
      if (subreg_lowpart_p (x))
        /* If this is a narrowing SUBREG and our operand is a REG, see
        /* If this is a narrowing SUBREG and our operand is a REG, see
           if we can find an equivalence for REG that is an arithmetic
           if we can find an equivalence for REG that is an arithmetic
           operation in a wider mode where both operands are
           operation in a wider mode where both operands are
           paradoxical SUBREGs from objects of our result mode.  In
           paradoxical SUBREGs from objects of our result mode.  In
           that case, we couldn-t report an equivalent value for that
           that case, we couldn-t report an equivalent value for that
           operation, since we don't know what the extra bits will be.
           operation, since we don't know what the extra bits will be.
           But we can find an equivalence for this SUBREG by folding
           But we can find an equivalence for this SUBREG by folding
           that operation in the narrow mode.  This allows us to fold
           that operation in the narrow mode.  This allows us to fold
           arithmetic in narrow modes when the machine only supports
           arithmetic in narrow modes when the machine only supports
           word-sized arithmetic.
           word-sized arithmetic.
 
 
           Also look for a case where we have a SUBREG whose operand
           Also look for a case where we have a SUBREG whose operand
           is the same as our result.  If both modes are smaller than
           is the same as our result.  If both modes are smaller than
           a word, we are simply interpreting a register in different
           a word, we are simply interpreting a register in different
           modes and we can use the inner value.  */
           modes and we can use the inner value.  */
 
 
        for (; elt; elt = elt->next_same_value)
        for (; elt; elt = elt->next_same_value)
          {
          {
            enum rtx_code eltcode = GET_CODE (elt->exp);
            enum rtx_code eltcode = GET_CODE (elt->exp);
 
 
            /* Just check for unary and binary operations.  */
            /* Just check for unary and binary operations.  */
            if (UNARY_P (elt->exp)
            if (UNARY_P (elt->exp)
                && eltcode != SIGN_EXTEND
                && eltcode != SIGN_EXTEND
                && eltcode != ZERO_EXTEND
                && eltcode != ZERO_EXTEND
                && GET_CODE (XEXP (elt->exp, 0)) == SUBREG
                && GET_CODE (XEXP (elt->exp, 0)) == SUBREG
                && GET_MODE (SUBREG_REG (XEXP (elt->exp, 0))) == mode
                && GET_MODE (SUBREG_REG (XEXP (elt->exp, 0))) == mode
                && (GET_MODE_CLASS (mode)
                && (GET_MODE_CLASS (mode)
                    == GET_MODE_CLASS (GET_MODE (XEXP (elt->exp, 0)))))
                    == GET_MODE_CLASS (GET_MODE (XEXP (elt->exp, 0)))))
              {
              {
                rtx op0 = SUBREG_REG (XEXP (elt->exp, 0));
                rtx op0 = SUBREG_REG (XEXP (elt->exp, 0));
 
 
                if (!REG_P (op0) && ! CONSTANT_P (op0))
                if (!REG_P (op0) && ! CONSTANT_P (op0))
                  op0 = fold_rtx (op0, NULL_RTX);
                  op0 = fold_rtx (op0, NULL_RTX);
 
 
                op0 = equiv_constant (op0);
                op0 = equiv_constant (op0);
                if (op0)
                if (op0)
                  new = simplify_unary_operation (GET_CODE (elt->exp), mode,
                  new = simplify_unary_operation (GET_CODE (elt->exp), mode,
                                                  op0, mode);
                                                  op0, mode);
              }
              }
            else if (ARITHMETIC_P (elt->exp)
            else if (ARITHMETIC_P (elt->exp)
                     && eltcode != DIV && eltcode != MOD
                     && eltcode != DIV && eltcode != MOD
                     && eltcode != UDIV && eltcode != UMOD
                     && eltcode != UDIV && eltcode != UMOD
                     && eltcode != ASHIFTRT && eltcode != LSHIFTRT
                     && eltcode != ASHIFTRT && eltcode != LSHIFTRT
                     && eltcode != ROTATE && eltcode != ROTATERT
                     && eltcode != ROTATE && eltcode != ROTATERT
                     && ((GET_CODE (XEXP (elt->exp, 0)) == SUBREG
                     && ((GET_CODE (XEXP (elt->exp, 0)) == SUBREG
                          && (GET_MODE (SUBREG_REG (XEXP (elt->exp, 0)))
                          && (GET_MODE (SUBREG_REG (XEXP (elt->exp, 0)))
                              == mode))
                              == mode))
                         || CONSTANT_P (XEXP (elt->exp, 0)))
                         || CONSTANT_P (XEXP (elt->exp, 0)))
                     && ((GET_CODE (XEXP (elt->exp, 1)) == SUBREG
                     && ((GET_CODE (XEXP (elt->exp, 1)) == SUBREG
                          && (GET_MODE (SUBREG_REG (XEXP (elt->exp, 1)))
                          && (GET_MODE (SUBREG_REG (XEXP (elt->exp, 1)))
                              == mode))
                              == mode))
                         || CONSTANT_P (XEXP (elt->exp, 1))))
                         || CONSTANT_P (XEXP (elt->exp, 1))))
              {
              {
                rtx op0 = gen_lowpart_common (mode, XEXP (elt->exp, 0));
                rtx op0 = gen_lowpart_common (mode, XEXP (elt->exp, 0));
                rtx op1 = gen_lowpart_common (mode, XEXP (elt->exp, 1));
                rtx op1 = gen_lowpart_common (mode, XEXP (elt->exp, 1));
 
 
                if (op0 && !REG_P (op0) && ! CONSTANT_P (op0))
                if (op0 && !REG_P (op0) && ! CONSTANT_P (op0))
                  op0 = fold_rtx (op0, NULL_RTX);
                  op0 = fold_rtx (op0, NULL_RTX);
 
 
                if (op0)
                if (op0)
                  op0 = equiv_constant (op0);
                  op0 = equiv_constant (op0);
 
 
                if (op1 && !REG_P (op1) && ! CONSTANT_P (op1))
                if (op1 && !REG_P (op1) && ! CONSTANT_P (op1))
                  op1 = fold_rtx (op1, NULL_RTX);
                  op1 = fold_rtx (op1, NULL_RTX);
 
 
                if (op1)
                if (op1)
                  op1 = equiv_constant (op1);
                  op1 = equiv_constant (op1);
 
 
                /* If we are looking for the low SImode part of
                /* If we are looking for the low SImode part of
                   (ashift:DI c (const_int 32)), it doesn't work to
                   (ashift:DI c (const_int 32)), it doesn't work to
                   compute that in SImode, because a 32-bit shift in
                   compute that in SImode, because a 32-bit shift in
                   SImode is unpredictable.  We know the value is
                   SImode is unpredictable.  We know the value is
                   0.  */
                   0.  */
                if (op0 && op1
                if (op0 && op1
                    && GET_CODE (elt->exp) == ASHIFT
                    && GET_CODE (elt->exp) == ASHIFT
                    && GET_CODE (op1) == CONST_INT
                    && GET_CODE (op1) == CONST_INT
                    && INTVAL (op1) >= GET_MODE_BITSIZE (mode))
                    && INTVAL (op1) >= GET_MODE_BITSIZE (mode))
                  {
                  {
                    if (INTVAL (op1)
                    if (INTVAL (op1)
                        < GET_MODE_BITSIZE (GET_MODE (elt->exp)))
                        < GET_MODE_BITSIZE (GET_MODE (elt->exp)))
                      /* If the count fits in the inner mode's width,
                      /* If the count fits in the inner mode's width,
                         but exceeds the outer mode's width, the value
                         but exceeds the outer mode's width, the value
                         will get truncated to 0 by the subreg.  */
                         will get truncated to 0 by the subreg.  */
                      new = CONST0_RTX (mode);
                      new = CONST0_RTX (mode);
                    else
                    else
                      /* If the count exceeds even the inner mode's width,
                      /* If the count exceeds even the inner mode's width,
                         don't fold this expression.  */
                         don't fold this expression.  */
                      new = 0;
                      new = 0;
                  }
                  }
                else if (op0 && op1)
                else if (op0 && op1)
                  new = simplify_binary_operation (GET_CODE (elt->exp),
                  new = simplify_binary_operation (GET_CODE (elt->exp),
                                                   mode, op0, op1);
                                                   mode, op0, op1);
              }
              }
 
 
            else if (GET_CODE (elt->exp) == SUBREG
            else if (GET_CODE (elt->exp) == SUBREG
                     && GET_MODE (SUBREG_REG (elt->exp)) == mode
                     && GET_MODE (SUBREG_REG (elt->exp)) == mode
                     && (GET_MODE_SIZE (GET_MODE (folded_arg0))
                     && (GET_MODE_SIZE (GET_MODE (folded_arg0))
                         <= UNITS_PER_WORD)
                         <= UNITS_PER_WORD)
                     && exp_equiv_p (elt->exp, elt->exp, 1, false))
                     && exp_equiv_p (elt->exp, elt->exp, 1, false))
              new = copy_rtx (SUBREG_REG (elt->exp));
              new = copy_rtx (SUBREG_REG (elt->exp));
 
 
            if (new)
            if (new)
              return new;
              return new;
          }
          }
      else
      else
        /* A SUBREG resulting from a zero extension may fold to zero
        /* A SUBREG resulting from a zero extension may fold to zero
           if it extracts higher bits than the ZERO_EXTEND's source
           if it extracts higher bits than the ZERO_EXTEND's source
           bits.  FIXME: if combine tried to, er, combine these
           bits.  FIXME: if combine tried to, er, combine these
           instructions, this transformation may be moved to
           instructions, this transformation may be moved to
           simplify_subreg.  */
           simplify_subreg.  */
        for (; elt; elt = elt->next_same_value)
        for (; elt; elt = elt->next_same_value)
          {
          {
            if (GET_CODE (elt->exp) == ZERO_EXTEND
            if (GET_CODE (elt->exp) == ZERO_EXTEND
                && subreg_lsb (x)
                && subreg_lsb (x)
                >= GET_MODE_BITSIZE (GET_MODE (XEXP (elt->exp, 0))))
                >= GET_MODE_BITSIZE (GET_MODE (XEXP (elt->exp, 0))))
              return CONST0_RTX (mode);
              return CONST0_RTX (mode);
          }
          }
    }
    }
 
 
  return x;
  return x;
}
}
 
 
/* Fold MEM.  Not to be called directly, see fold_rtx_mem instead.  */
/* Fold MEM.  Not to be called directly, see fold_rtx_mem instead.  */
 
 
static rtx
static rtx
fold_rtx_mem_1 (rtx x, rtx insn)
fold_rtx_mem_1 (rtx x, rtx insn)
{
{
  enum machine_mode mode = GET_MODE (x);
  enum machine_mode mode = GET_MODE (x);
  rtx new;
  rtx new;
 
 
  /* If we are not actually processing an insn, don't try to find the
  /* If we are not actually processing an insn, don't try to find the
     best address.  Not only don't we care, but we could modify the
     best address.  Not only don't we care, but we could modify the
     MEM in an invalid way since we have no insn to validate
     MEM in an invalid way since we have no insn to validate
     against.  */
     against.  */
  if (insn != 0)
  if (insn != 0)
    find_best_addr (insn, &XEXP (x, 0), mode);
    find_best_addr (insn, &XEXP (x, 0), mode);
 
 
  {
  {
    /* Even if we don't fold in the insn itself, we can safely do so
    /* Even if we don't fold in the insn itself, we can safely do so
       here, in hopes of getting a constant.  */
       here, in hopes of getting a constant.  */
    rtx addr = fold_rtx (XEXP (x, 0), NULL_RTX);
    rtx addr = fold_rtx (XEXP (x, 0), NULL_RTX);
    rtx base = 0;
    rtx base = 0;
    HOST_WIDE_INT offset = 0;
    HOST_WIDE_INT offset = 0;
 
 
    if (REG_P (addr)
    if (REG_P (addr)
        && REGNO_QTY_VALID_P (REGNO (addr)))
        && REGNO_QTY_VALID_P (REGNO (addr)))
      {
      {
        int addr_q = REG_QTY (REGNO (addr));
        int addr_q = REG_QTY (REGNO (addr));
        struct qty_table_elem *addr_ent = &qty_table[addr_q];
        struct qty_table_elem *addr_ent = &qty_table[addr_q];
 
 
        if (GET_MODE (addr) == addr_ent->mode
        if (GET_MODE (addr) == addr_ent->mode
            && addr_ent->const_rtx != NULL_RTX)
            && addr_ent->const_rtx != NULL_RTX)
          addr = addr_ent->const_rtx;
          addr = addr_ent->const_rtx;
      }
      }
 
 
    /* Call target hook to avoid the effects of -fpic etc....  */
    /* Call target hook to avoid the effects of -fpic etc....  */
    addr = targetm.delegitimize_address (addr);
    addr = targetm.delegitimize_address (addr);
 
 
    /* If address is constant, split it into a base and integer
    /* If address is constant, split it into a base and integer
       offset.  */
       offset.  */
    if (GET_CODE (addr) == SYMBOL_REF || GET_CODE (addr) == LABEL_REF)
    if (GET_CODE (addr) == SYMBOL_REF || GET_CODE (addr) == LABEL_REF)
      base = addr;
      base = addr;
    else if (GET_CODE (addr) == CONST && GET_CODE (XEXP (addr, 0)) == PLUS
    else if (GET_CODE (addr) == CONST && GET_CODE (XEXP (addr, 0)) == PLUS
             && GET_CODE (XEXP (XEXP (addr, 0), 1)) == CONST_INT)
             && GET_CODE (XEXP (XEXP (addr, 0), 1)) == CONST_INT)
      {
      {
        base = XEXP (XEXP (addr, 0), 0);
        base = XEXP (XEXP (addr, 0), 0);
        offset = INTVAL (XEXP (XEXP (addr, 0), 1));
        offset = INTVAL (XEXP (XEXP (addr, 0), 1));
      }
      }
    else if (GET_CODE (addr) == LO_SUM
    else if (GET_CODE (addr) == LO_SUM
             && GET_CODE (XEXP (addr, 1)) == SYMBOL_REF)
             && GET_CODE (XEXP (addr, 1)) == SYMBOL_REF)
      base = XEXP (addr, 1);
      base = XEXP (addr, 1);
 
 
    /* If this is a constant pool reference, we can fold it into its
    /* If this is a constant pool reference, we can fold it into its
       constant to allow better value tracking.  */
       constant to allow better value tracking.  */
    if (base && GET_CODE (base) == SYMBOL_REF
    if (base && GET_CODE (base) == SYMBOL_REF
        && CONSTANT_POOL_ADDRESS_P (base))
        && CONSTANT_POOL_ADDRESS_P (base))
      {
      {
        rtx constant = get_pool_constant (base);
        rtx constant = get_pool_constant (base);
        enum machine_mode const_mode = get_pool_mode (base);
        enum machine_mode const_mode = get_pool_mode (base);
        rtx new;
        rtx new;
 
 
        if (CONSTANT_P (constant) && GET_CODE (constant) != CONST_INT)
        if (CONSTANT_P (constant) && GET_CODE (constant) != CONST_INT)
          {
          {
            constant_pool_entries_cost = COST (constant);
            constant_pool_entries_cost = COST (constant);
            constant_pool_entries_regcost = approx_reg_cost (constant);
            constant_pool_entries_regcost = approx_reg_cost (constant);
          }
          }
 
 
        /* If we are loading the full constant, we have an
        /* If we are loading the full constant, we have an
           equivalence.  */
           equivalence.  */
        if (offset == 0 && mode == const_mode)
        if (offset == 0 && mode == const_mode)
          return constant;
          return constant;
 
 
        /* If this actually isn't a constant (weird!), we can't do
        /* If this actually isn't a constant (weird!), we can't do
           anything.  Otherwise, handle the two most common cases:
           anything.  Otherwise, handle the two most common cases:
           extracting a word from a multi-word constant, and
           extracting a word from a multi-word constant, and
           extracting the low-order bits.  Other cases don't seem
           extracting the low-order bits.  Other cases don't seem
           common enough to worry about.  */
           common enough to worry about.  */
        if (! CONSTANT_P (constant))
        if (! CONSTANT_P (constant))
          return x;
          return x;
 
 
        if (GET_MODE_CLASS (mode) == MODE_INT
        if (GET_MODE_CLASS (mode) == MODE_INT
            && GET_MODE_SIZE (mode) == UNITS_PER_WORD
            && GET_MODE_SIZE (mode) == UNITS_PER_WORD
            && offset % UNITS_PER_WORD == 0
            && offset % UNITS_PER_WORD == 0
            && (new = operand_subword (constant,
            && (new = operand_subword (constant,
                                       offset / UNITS_PER_WORD,
                                       offset / UNITS_PER_WORD,
                                       0, const_mode)) != 0)
                                       0, const_mode)) != 0)
          return new;
          return new;
 
 
        if (((BYTES_BIG_ENDIAN
        if (((BYTES_BIG_ENDIAN
              && offset == GET_MODE_SIZE (GET_MODE (constant)) - 1)
              && offset == GET_MODE_SIZE (GET_MODE (constant)) - 1)
             || (! BYTES_BIG_ENDIAN && offset == 0))
             || (! BYTES_BIG_ENDIAN && offset == 0))
            && (new = gen_lowpart (mode, constant)) != 0)
            && (new = gen_lowpart (mode, constant)) != 0)
          return new;
          return new;
      }
      }
 
 
    /* If this is a reference to a label at a known position in a jump
    /* If this is a reference to a label at a known position in a jump
       table, we also know its value.  */
       table, we also know its value.  */
    if (base && GET_CODE (base) == LABEL_REF)
    if (base && GET_CODE (base) == LABEL_REF)
      {
      {
        rtx label = XEXP (base, 0);
        rtx label = XEXP (base, 0);
        rtx table_insn = NEXT_INSN (label);
        rtx table_insn = NEXT_INSN (label);
 
 
        if (table_insn && JUMP_P (table_insn)
        if (table_insn && JUMP_P (table_insn)
            && GET_CODE (PATTERN (table_insn)) == ADDR_VEC)
            && GET_CODE (PATTERN (table_insn)) == ADDR_VEC)
          {
          {
            rtx table = PATTERN (table_insn);
            rtx table = PATTERN (table_insn);
 
 
            if (offset >= 0
            if (offset >= 0
                && (offset / GET_MODE_SIZE (GET_MODE (table))
                && (offset / GET_MODE_SIZE (GET_MODE (table))
                    < XVECLEN (table, 0)))
                    < XVECLEN (table, 0)))
              {
              {
                rtx label = XVECEXP
                rtx label = XVECEXP
                  (table, 0, offset / GET_MODE_SIZE (GET_MODE (table)));
                  (table, 0, offset / GET_MODE_SIZE (GET_MODE (table)));
                rtx set;
                rtx set;
 
 
                /* If we have an insn that loads the label from the
                /* If we have an insn that loads the label from the
                   jumptable into a reg, we don't want to set the reg
                   jumptable into a reg, we don't want to set the reg
                   to the label, because this may cause a reference to
                   to the label, because this may cause a reference to
                   the label to remain after the label is removed in
                   the label to remain after the label is removed in
                   some very obscure cases (PR middle-end/18628).  */
                   some very obscure cases (PR middle-end/18628).  */
                if (!insn)
                if (!insn)
                  return label;
                  return label;
 
 
                set = single_set (insn);
                set = single_set (insn);
 
 
                if (! set || SET_SRC (set) != x)
                if (! set || SET_SRC (set) != x)
                  return x;
                  return x;
 
 
                /* If it's a jump, it's safe to reference the label.  */
                /* If it's a jump, it's safe to reference the label.  */
                if (SET_DEST (set) == pc_rtx)
                if (SET_DEST (set) == pc_rtx)
                  return label;
                  return label;
 
 
                return x;
                return x;
              }
              }
          }
          }
        if (table_insn && JUMP_P (table_insn)
        if (table_insn && JUMP_P (table_insn)
            && GET_CODE (PATTERN (table_insn)) == ADDR_DIFF_VEC)
            && GET_CODE (PATTERN (table_insn)) == ADDR_DIFF_VEC)
          {
          {
            rtx table = PATTERN (table_insn);
            rtx table = PATTERN (table_insn);
 
 
            if (offset >= 0
            if (offset >= 0
                && (offset / GET_MODE_SIZE (GET_MODE (table))
                && (offset / GET_MODE_SIZE (GET_MODE (table))
                    < XVECLEN (table, 1)))
                    < XVECLEN (table, 1)))
              {
              {
                offset /= GET_MODE_SIZE (GET_MODE (table));
                offset /= GET_MODE_SIZE (GET_MODE (table));
                new = gen_rtx_MINUS (Pmode, XVECEXP (table, 1, offset),
                new = gen_rtx_MINUS (Pmode, XVECEXP (table, 1, offset),
                                     XEXP (table, 0));
                                     XEXP (table, 0));
 
 
                if (GET_MODE (table) != Pmode)
                if (GET_MODE (table) != Pmode)
                  new = gen_rtx_TRUNCATE (GET_MODE (table), new);
                  new = gen_rtx_TRUNCATE (GET_MODE (table), new);
 
 
                /* Indicate this is a constant.  This isn't a valid
                /* Indicate this is a constant.  This isn't a valid
                   form of CONST, but it will only be used to fold the
                   form of CONST, but it will only be used to fold the
                   next insns and then discarded, so it should be
                   next insns and then discarded, so it should be
                   safe.
                   safe.
 
 
                   Note this expression must be explicitly discarded,
                   Note this expression must be explicitly discarded,
                   by cse_insn, else it may end up in a REG_EQUAL note
                   by cse_insn, else it may end up in a REG_EQUAL note
                   and "escape" to cause problems elsewhere.  */
                   and "escape" to cause problems elsewhere.  */
                return gen_rtx_CONST (GET_MODE (new), new);
                return gen_rtx_CONST (GET_MODE (new), new);
              }
              }
          }
          }
      }
      }
 
 
    return x;
    return x;
  }
  }
}
}
 
 
/* Fold MEM.  */
/* Fold MEM.  */
 
 
static rtx
static rtx
fold_rtx_mem (rtx x, rtx insn)
fold_rtx_mem (rtx x, rtx insn)
{
{
  /* To avoid infinite oscillations between fold_rtx and fold_rtx_mem,
  /* To avoid infinite oscillations between fold_rtx and fold_rtx_mem,
     refuse to allow recursion of the latter past n levels.  This can
     refuse to allow recursion of the latter past n levels.  This can
     happen because fold_rtx_mem will try to fold the address of the
     happen because fold_rtx_mem will try to fold the address of the
     memory reference it is passed, i.e. conceptually throwing away
     memory reference it is passed, i.e. conceptually throwing away
     the MEM and reinjecting the bare address into fold_rtx.  As a
     the MEM and reinjecting the bare address into fold_rtx.  As a
     result, patterns like
     result, patterns like
 
 
       set (reg1)
       set (reg1)
           (plus (reg)
           (plus (reg)
                 (mem (plus (reg2) (const_int))))
                 (mem (plus (reg2) (const_int))))
 
 
       set (reg2)
       set (reg2)
           (plus (reg)
           (plus (reg)
                 (mem (plus (reg1) (const_int))))
                 (mem (plus (reg1) (const_int))))
 
 
     will defeat any "first-order" short-circuit put in either
     will defeat any "first-order" short-circuit put in either
     function to prevent these infinite oscillations.
     function to prevent these infinite oscillations.
 
 
     The heuristics for determining n is as follows: since each time
     The heuristics for determining n is as follows: since each time
     it is invoked fold_rtx_mem throws away a MEM, and since MEMs
     it is invoked fold_rtx_mem throws away a MEM, and since MEMs
     are generically not nested, we assume that each invocation of
     are generically not nested, we assume that each invocation of
     fold_rtx_mem corresponds to a new "top-level" operand, i.e.
     fold_rtx_mem corresponds to a new "top-level" operand, i.e.
     the source or the destination of a SET.  So fold_rtx_mem is
     the source or the destination of a SET.  So fold_rtx_mem is
     bound to stop or cycle before n recursions, n being the number
     bound to stop or cycle before n recursions, n being the number
     of expressions recorded in the hash table.  We also leave some
     of expressions recorded in the hash table.  We also leave some
     play to account for the initial steps.  */
     play to account for the initial steps.  */
 
 
  static unsigned int depth;
  static unsigned int depth;
  rtx ret;
  rtx ret;
 
 
  if (depth > 3 + table_size)
  if (depth > 3 + table_size)
    return x;
    return x;
 
 
  depth++;
  depth++;
  ret = fold_rtx_mem_1 (x, insn);
  ret = fold_rtx_mem_1 (x, insn);
  depth--;
  depth--;
 
 
  return ret;
  return ret;
}
}
 
 
/* If X is a nontrivial arithmetic operation on an argument
/* If X is a nontrivial arithmetic operation on an argument
   for which a constant value can be determined, return
   for which a constant value can be determined, return
   the result of operating on that value, as a constant.
   the result of operating on that value, as a constant.
   Otherwise, return X, possibly with one or more operands
   Otherwise, return X, possibly with one or more operands
   modified by recursive calls to this function.
   modified by recursive calls to this function.
 
 
   If X is a register whose contents are known, we do NOT
   If X is a register whose contents are known, we do NOT
   return those contents here.  equiv_constant is called to
   return those contents here.  equiv_constant is called to
   perform that task.
   perform that task.
 
 
   INSN is the insn that we may be modifying.  If it is 0, make a copy
   INSN is the insn that we may be modifying.  If it is 0, make a copy
   of X before modifying it.  */
   of X before modifying it.  */
 
 
static rtx
static rtx
fold_rtx (rtx x, rtx insn)
fold_rtx (rtx x, rtx insn)
{
{
  enum rtx_code code;
  enum rtx_code code;
  enum machine_mode mode;
  enum machine_mode mode;
  const char *fmt;
  const char *fmt;
  int i;
  int i;
  rtx new = 0;
  rtx new = 0;
  int copied = 0;
  int copied = 0;
  int must_swap = 0;
  int must_swap = 0;
 
 
  /* Folded equivalents of first two operands of X.  */
  /* Folded equivalents of first two operands of X.  */
  rtx folded_arg0;
  rtx folded_arg0;
  rtx folded_arg1;
  rtx folded_arg1;
 
 
  /* Constant equivalents of first three operands of X;
  /* Constant equivalents of first three operands of X;
     0 when no such equivalent is known.  */
     0 when no such equivalent is known.  */
  rtx const_arg0;
  rtx const_arg0;
  rtx const_arg1;
  rtx const_arg1;
  rtx const_arg2;
  rtx const_arg2;
 
 
  /* The mode of the first operand of X.  We need this for sign and zero
  /* The mode of the first operand of X.  We need this for sign and zero
     extends.  */
     extends.  */
  enum machine_mode mode_arg0;
  enum machine_mode mode_arg0;
 
 
  if (x == 0)
  if (x == 0)
    return x;
    return x;
 
 
  mode = GET_MODE (x);
  mode = GET_MODE (x);
  code = GET_CODE (x);
  code = GET_CODE (x);
  switch (code)
  switch (code)
    {
    {
    case CONST:
    case CONST:
    case CONST_INT:
    case CONST_INT:
    case CONST_DOUBLE:
    case CONST_DOUBLE:
    case CONST_VECTOR:
    case CONST_VECTOR:
    case SYMBOL_REF:
    case SYMBOL_REF:
    case LABEL_REF:
    case LABEL_REF:
    case REG:
    case REG:
    case PC:
    case PC:
      /* No use simplifying an EXPR_LIST
      /* No use simplifying an EXPR_LIST
         since they are used only for lists of args
         since they are used only for lists of args
         in a function call's REG_EQUAL note.  */
         in a function call's REG_EQUAL note.  */
    case EXPR_LIST:
    case EXPR_LIST:
      return x;
      return x;
 
 
#ifdef HAVE_cc0
#ifdef HAVE_cc0
    case CC0:
    case CC0:
      return prev_insn_cc0;
      return prev_insn_cc0;
#endif
#endif
 
 
    case SUBREG:
    case SUBREG:
      return fold_rtx_subreg (x, insn);
      return fold_rtx_subreg (x, insn);
 
 
    case NOT:
    case NOT:
    case NEG:
    case NEG:
      /* If we have (NOT Y), see if Y is known to be (NOT Z).
      /* If we have (NOT Y), see if Y is known to be (NOT Z).
         If so, (NOT Y) simplifies to Z.  Similarly for NEG.  */
         If so, (NOT Y) simplifies to Z.  Similarly for NEG.  */
      new = lookup_as_function (XEXP (x, 0), code);
      new = lookup_as_function (XEXP (x, 0), code);
      if (new)
      if (new)
        return fold_rtx (copy_rtx (XEXP (new, 0)), insn);
        return fold_rtx (copy_rtx (XEXP (new, 0)), insn);
      break;
      break;
 
 
    case MEM:
    case MEM:
      return fold_rtx_mem (x, insn);
      return fold_rtx_mem (x, insn);
 
 
#ifdef NO_FUNCTION_CSE
#ifdef NO_FUNCTION_CSE
    case CALL:
    case CALL:
      if (CONSTANT_P (XEXP (XEXP (x, 0), 0)))
      if (CONSTANT_P (XEXP (XEXP (x, 0), 0)))
        return x;
        return x;
      break;
      break;
#endif
#endif
 
 
    case ASM_OPERANDS:
    case ASM_OPERANDS:
      if (insn)
      if (insn)
        {
        {
          for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--)
          for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--)
            validate_change (insn, &ASM_OPERANDS_INPUT (x, i),
            validate_change (insn, &ASM_OPERANDS_INPUT (x, i),
                             fold_rtx (ASM_OPERANDS_INPUT (x, i), insn), 0);
                             fold_rtx (ASM_OPERANDS_INPUT (x, i), insn), 0);
        }
        }
      break;
      break;
 
 
    default:
    default:
      break;
      break;
    }
    }
 
 
  const_arg0 = 0;
  const_arg0 = 0;
  const_arg1 = 0;
  const_arg1 = 0;
  const_arg2 = 0;
  const_arg2 = 0;
  mode_arg0 = VOIDmode;
  mode_arg0 = VOIDmode;
 
 
  /* Try folding our operands.
  /* Try folding our operands.
     Then see which ones have constant values known.  */
     Then see which ones have constant values known.  */
 
 
  fmt = GET_RTX_FORMAT (code);
  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    if (fmt[i] == 'e')
    if (fmt[i] == 'e')
      {
      {
        rtx arg = XEXP (x, i);
        rtx arg = XEXP (x, i);
        rtx folded_arg = arg, const_arg = 0;
        rtx folded_arg = arg, const_arg = 0;
        enum machine_mode mode_arg = GET_MODE (arg);
        enum machine_mode mode_arg = GET_MODE (arg);
        rtx cheap_arg, expensive_arg;
        rtx cheap_arg, expensive_arg;
        rtx replacements[2];
        rtx replacements[2];
        int j;
        int j;
        int old_cost = COST_IN (XEXP (x, i), code);
        int old_cost = COST_IN (XEXP (x, i), code);
 
 
        /* Most arguments are cheap, so handle them specially.  */
        /* Most arguments are cheap, so handle them specially.  */
        switch (GET_CODE (arg))
        switch (GET_CODE (arg))
          {
          {
          case REG:
          case REG:
            /* This is the same as calling equiv_constant; it is duplicated
            /* This is the same as calling equiv_constant; it is duplicated
               here for speed.  */
               here for speed.  */
            if (REGNO_QTY_VALID_P (REGNO (arg)))
            if (REGNO_QTY_VALID_P (REGNO (arg)))
              {
              {
                int arg_q = REG_QTY (REGNO (arg));
                int arg_q = REG_QTY (REGNO (arg));
                struct qty_table_elem *arg_ent = &qty_table[arg_q];
                struct qty_table_elem *arg_ent = &qty_table[arg_q];
 
 
                if (arg_ent->const_rtx != NULL_RTX
                if (arg_ent->const_rtx != NULL_RTX
                    && !REG_P (arg_ent->const_rtx)
                    && !REG_P (arg_ent->const_rtx)
                    && GET_CODE (arg_ent->const_rtx) != PLUS)
                    && GET_CODE (arg_ent->const_rtx) != PLUS)
                  const_arg
                  const_arg
                    = gen_lowpart (GET_MODE (arg),
                    = gen_lowpart (GET_MODE (arg),
                                               arg_ent->const_rtx);
                                               arg_ent->const_rtx);
              }
              }
            break;
            break;
 
 
          case CONST:
          case CONST:
          case CONST_INT:
          case CONST_INT:
          case SYMBOL_REF:
          case SYMBOL_REF:
          case LABEL_REF:
          case LABEL_REF:
          case CONST_DOUBLE:
          case CONST_DOUBLE:
          case CONST_VECTOR:
          case CONST_VECTOR:
            const_arg = arg;
            const_arg = arg;
            break;
            break;
 
 
#ifdef HAVE_cc0
#ifdef HAVE_cc0
          case CC0:
          case CC0:
            folded_arg = prev_insn_cc0;
            folded_arg = prev_insn_cc0;
            mode_arg = prev_insn_cc0_mode;
            mode_arg = prev_insn_cc0_mode;
            const_arg = equiv_constant (folded_arg);
            const_arg = equiv_constant (folded_arg);
            break;
            break;
#endif
#endif
 
 
          default:
          default:
            folded_arg = fold_rtx (arg, insn);
            folded_arg = fold_rtx (arg, insn);
            const_arg = equiv_constant (folded_arg);
            const_arg = equiv_constant (folded_arg);
          }
          }
 
 
        /* For the first three operands, see if the operand
        /* For the first three operands, see if the operand
           is constant or equivalent to a constant.  */
           is constant or equivalent to a constant.  */
        switch (i)
        switch (i)
          {
          {
          case 0:
          case 0:
            folded_arg0 = folded_arg;
            folded_arg0 = folded_arg;
            const_arg0 = const_arg;
            const_arg0 = const_arg;
            mode_arg0 = mode_arg;
            mode_arg0 = mode_arg;
            break;
            break;
          case 1:
          case 1:
            folded_arg1 = folded_arg;
            folded_arg1 = folded_arg;
            const_arg1 = const_arg;
            const_arg1 = const_arg;
            break;
            break;
          case 2:
          case 2:
            const_arg2 = const_arg;
            const_arg2 = const_arg;
            break;
            break;
          }
          }
 
 
        /* Pick the least expensive of the folded argument and an
        /* Pick the least expensive of the folded argument and an
           equivalent constant argument.  */
           equivalent constant argument.  */
        if (const_arg == 0 || const_arg == folded_arg
        if (const_arg == 0 || const_arg == folded_arg
            || COST_IN (const_arg, code) > COST_IN (folded_arg, code))
            || COST_IN (const_arg, code) > COST_IN (folded_arg, code))
          cheap_arg = folded_arg, expensive_arg = const_arg;
          cheap_arg = folded_arg, expensive_arg = const_arg;
        else
        else
          cheap_arg = const_arg, expensive_arg = folded_arg;
          cheap_arg = const_arg, expensive_arg = folded_arg;
 
 
        /* Try to replace the operand with the cheapest of the two
        /* Try to replace the operand with the cheapest of the two
           possibilities.  If it doesn't work and this is either of the first
           possibilities.  If it doesn't work and this is either of the first
           two operands of a commutative operation, try swapping them.
           two operands of a commutative operation, try swapping them.
           If THAT fails, try the more expensive, provided it is cheaper
           If THAT fails, try the more expensive, provided it is cheaper
           than what is already there.  */
           than what is already there.  */
 
 
        if (cheap_arg == XEXP (x, i))
        if (cheap_arg == XEXP (x, i))
          continue;
          continue;
 
 
        if (insn == 0 && ! copied)
        if (insn == 0 && ! copied)
          {
          {
            x = copy_rtx (x);
            x = copy_rtx (x);
            copied = 1;
            copied = 1;
          }
          }
 
 
        /* Order the replacements from cheapest to most expensive.  */
        /* Order the replacements from cheapest to most expensive.  */
        replacements[0] = cheap_arg;
        replacements[0] = cheap_arg;
        replacements[1] = expensive_arg;
        replacements[1] = expensive_arg;
 
 
        for (j = 0; j < 2 && replacements[j]; j++)
        for (j = 0; j < 2 && replacements[j]; j++)
          {
          {
            int new_cost = COST_IN (replacements[j], code);
            int new_cost = COST_IN (replacements[j], code);
 
 
            /* Stop if what existed before was cheaper.  Prefer constants
            /* Stop if what existed before was cheaper.  Prefer constants
               in the case of a tie.  */
               in the case of a tie.  */
            if (new_cost > old_cost
            if (new_cost > old_cost
                || (new_cost == old_cost && CONSTANT_P (XEXP (x, i))))
                || (new_cost == old_cost && CONSTANT_P (XEXP (x, i))))
              break;
              break;
 
 
            /* It's not safe to substitute the operand of a conversion
            /* It's not safe to substitute the operand of a conversion
               operator with a constant, as the conversion's identity
               operator with a constant, as the conversion's identity
               depends upon the mode of its operand.  This optimization
               depends upon the mode of its operand.  This optimization
               is handled by the call to simplify_unary_operation.  */
               is handled by the call to simplify_unary_operation.  */
            if (GET_RTX_CLASS (code) == RTX_UNARY
            if (GET_RTX_CLASS (code) == RTX_UNARY
                && GET_MODE (replacements[j]) != mode_arg0
                && GET_MODE (replacements[j]) != mode_arg0
                && (code == ZERO_EXTEND
                && (code == ZERO_EXTEND
                    || code == SIGN_EXTEND
                    || code == SIGN_EXTEND
                    || code == TRUNCATE
                    || code == TRUNCATE
                    || code == FLOAT_TRUNCATE
                    || code == FLOAT_TRUNCATE
                    || code == FLOAT_EXTEND
                    || code == FLOAT_EXTEND
                    || code == FLOAT
                    || code == FLOAT
                    || code == FIX
                    || code == FIX
                    || code == UNSIGNED_FLOAT
                    || code == UNSIGNED_FLOAT
                    || code == UNSIGNED_FIX))
                    || code == UNSIGNED_FIX))
              continue;
              continue;
 
 
            if (validate_change (insn, &XEXP (x, i), replacements[j], 0))
            if (validate_change (insn, &XEXP (x, i), replacements[j], 0))
              break;
              break;
 
 
            if (GET_RTX_CLASS (code) == RTX_COMM_COMPARE
            if (GET_RTX_CLASS (code) == RTX_COMM_COMPARE
                || GET_RTX_CLASS (code) == RTX_COMM_ARITH)
                || GET_RTX_CLASS (code) == RTX_COMM_ARITH)
              {
              {
                validate_change (insn, &XEXP (x, i), XEXP (x, 1 - i), 1);
                validate_change (insn, &XEXP (x, i), XEXP (x, 1 - i), 1);
                validate_change (insn, &XEXP (x, 1 - i), replacements[j], 1);
                validate_change (insn, &XEXP (x, 1 - i), replacements[j], 1);
 
 
                if (apply_change_group ())
                if (apply_change_group ())
                  {
                  {
                    /* Swap them back to be invalid so that this loop can
                    /* Swap them back to be invalid so that this loop can
                       continue and flag them to be swapped back later.  */
                       continue and flag them to be swapped back later.  */
                    rtx tem;
                    rtx tem;
 
 
                    tem = XEXP (x, 0); XEXP (x, 0) = XEXP (x, 1);
                    tem = XEXP (x, 0); XEXP (x, 0) = XEXP (x, 1);
                                       XEXP (x, 1) = tem;
                                       XEXP (x, 1) = tem;
                    must_swap = 1;
                    must_swap = 1;
                    break;
                    break;
                  }
                  }
              }
              }
          }
          }
      }
      }
 
 
    else
    else
      {
      {
        if (fmt[i] == 'E')
        if (fmt[i] == 'E')
          /* Don't try to fold inside of a vector of expressions.
          /* Don't try to fold inside of a vector of expressions.
             Doing nothing is harmless.  */
             Doing nothing is harmless.  */
          {;}
          {;}
      }
      }
 
 
  /* If a commutative operation, place a constant integer as the second
  /* If a commutative operation, place a constant integer as the second
     operand unless the first operand is also a constant integer.  Otherwise,
     operand unless the first operand is also a constant integer.  Otherwise,
     place any constant second unless the first operand is also a constant.  */
     place any constant second unless the first operand is also a constant.  */
 
 
  if (COMMUTATIVE_P (x))
  if (COMMUTATIVE_P (x))
    {
    {
      if (must_swap
      if (must_swap
          || swap_commutative_operands_p (const_arg0 ? const_arg0
          || swap_commutative_operands_p (const_arg0 ? const_arg0
                                                     : XEXP (x, 0),
                                                     : XEXP (x, 0),
                                          const_arg1 ? const_arg1
                                          const_arg1 ? const_arg1
                                                     : XEXP (x, 1)))
                                                     : XEXP (x, 1)))
        {
        {
          rtx tem = XEXP (x, 0);
          rtx tem = XEXP (x, 0);
 
 
          if (insn == 0 && ! copied)
          if (insn == 0 && ! copied)
            {
            {
              x = copy_rtx (x);
              x = copy_rtx (x);
              copied = 1;
              copied = 1;
            }
            }
 
 
          validate_change (insn, &XEXP (x, 0), XEXP (x, 1), 1);
          validate_change (insn, &XEXP (x, 0), XEXP (x, 1), 1);
          validate_change (insn, &XEXP (x, 1), tem, 1);
          validate_change (insn, &XEXP (x, 1), tem, 1);
          if (apply_change_group ())
          if (apply_change_group ())
            {
            {
              tem = const_arg0, const_arg0 = const_arg1, const_arg1 = tem;
              tem = const_arg0, const_arg0 = const_arg1, const_arg1 = tem;
              tem = folded_arg0, folded_arg0 = folded_arg1, folded_arg1 = tem;
              tem = folded_arg0, folded_arg0 = folded_arg1, folded_arg1 = tem;
            }
            }
        }
        }
    }
    }
 
 
  /* If X is an arithmetic operation, see if we can simplify it.  */
  /* If X is an arithmetic operation, see if we can simplify it.  */
 
 
  switch (GET_RTX_CLASS (code))
  switch (GET_RTX_CLASS (code))
    {
    {
    case RTX_UNARY:
    case RTX_UNARY:
      {
      {
        int is_const = 0;
        int is_const = 0;
 
 
        /* We can't simplify extension ops unless we know the
        /* We can't simplify extension ops unless we know the
           original mode.  */
           original mode.  */
        if ((code == ZERO_EXTEND || code == SIGN_EXTEND)
        if ((code == ZERO_EXTEND || code == SIGN_EXTEND)
            && mode_arg0 == VOIDmode)
            && mode_arg0 == VOIDmode)
          break;
          break;
 
 
        /* If we had a CONST, strip it off and put it back later if we
        /* If we had a CONST, strip it off and put it back later if we
           fold.  */
           fold.  */
        if (const_arg0 != 0 && GET_CODE (const_arg0) == CONST)
        if (const_arg0 != 0 && GET_CODE (const_arg0) == CONST)
          is_const = 1, const_arg0 = XEXP (const_arg0, 0);
          is_const = 1, const_arg0 = XEXP (const_arg0, 0);
 
 
        new = simplify_unary_operation (code, mode,
        new = simplify_unary_operation (code, mode,
                                        const_arg0 ? const_arg0 : folded_arg0,
                                        const_arg0 ? const_arg0 : folded_arg0,
                                        mode_arg0);
                                        mode_arg0);
        /* NEG of PLUS could be converted into MINUS, but that causes
        /* NEG of PLUS could be converted into MINUS, but that causes
           expressions of the form
           expressions of the form
           (CONST (MINUS (CONST_INT) (SYMBOL_REF)))
           (CONST (MINUS (CONST_INT) (SYMBOL_REF)))
           which many ports mistakenly treat as LEGITIMATE_CONSTANT_P.
           which many ports mistakenly treat as LEGITIMATE_CONSTANT_P.
           FIXME: those ports should be fixed.  */
           FIXME: those ports should be fixed.  */
        if (new != 0 && is_const
        if (new != 0 && is_const
            && GET_CODE (new) == PLUS
            && GET_CODE (new) == PLUS
            && (GET_CODE (XEXP (new, 0)) == SYMBOL_REF
            && (GET_CODE (XEXP (new, 0)) == SYMBOL_REF
                || GET_CODE (XEXP (new, 0)) == LABEL_REF)
                || GET_CODE (XEXP (new, 0)) == LABEL_REF)
            && GET_CODE (XEXP (new, 1)) == CONST_INT)
            && GET_CODE (XEXP (new, 1)) == CONST_INT)
          new = gen_rtx_CONST (mode, new);
          new = gen_rtx_CONST (mode, new);
      }
      }
      break;
      break;
 
 
    case RTX_COMPARE:
    case RTX_COMPARE:
    case RTX_COMM_COMPARE:
    case RTX_COMM_COMPARE:
      /* See what items are actually being compared and set FOLDED_ARG[01]
      /* See what items are actually being compared and set FOLDED_ARG[01]
         to those values and CODE to the actual comparison code.  If any are
         to those values and CODE to the actual comparison code.  If any are
         constant, set CONST_ARG0 and CONST_ARG1 appropriately.  We needn't
         constant, set CONST_ARG0 and CONST_ARG1 appropriately.  We needn't
         do anything if both operands are already known to be constant.  */
         do anything if both operands are already known to be constant.  */
 
 
      /* ??? Vector mode comparisons are not supported yet.  */
      /* ??? Vector mode comparisons are not supported yet.  */
      if (VECTOR_MODE_P (mode))
      if (VECTOR_MODE_P (mode))
        break;
        break;
 
 
      if (const_arg0 == 0 || const_arg1 == 0)
      if (const_arg0 == 0 || const_arg1 == 0)
        {
        {
          struct table_elt *p0, *p1;
          struct table_elt *p0, *p1;
          rtx true_rtx = const_true_rtx, false_rtx = const0_rtx;
          rtx true_rtx = const_true_rtx, false_rtx = const0_rtx;
          enum machine_mode mode_arg1;
          enum machine_mode mode_arg1;
 
 
#ifdef FLOAT_STORE_FLAG_VALUE
#ifdef FLOAT_STORE_FLAG_VALUE
          if (SCALAR_FLOAT_MODE_P (mode))
          if (SCALAR_FLOAT_MODE_P (mode))
            {
            {
              true_rtx = (CONST_DOUBLE_FROM_REAL_VALUE
              true_rtx = (CONST_DOUBLE_FROM_REAL_VALUE
                          (FLOAT_STORE_FLAG_VALUE (mode), mode));
                          (FLOAT_STORE_FLAG_VALUE (mode), mode));
              false_rtx = CONST0_RTX (mode);
              false_rtx = CONST0_RTX (mode);
            }
            }
#endif
#endif
 
 
          code = find_comparison_args (code, &folded_arg0, &folded_arg1,
          code = find_comparison_args (code, &folded_arg0, &folded_arg1,
                                       &mode_arg0, &mode_arg1);
                                       &mode_arg0, &mode_arg1);
 
 
          /* If the mode is VOIDmode or a MODE_CC mode, we don't know
          /* If the mode is VOIDmode or a MODE_CC mode, we don't know
             what kinds of things are being compared, so we can't do
             what kinds of things are being compared, so we can't do
             anything with this comparison.  */
             anything with this comparison.  */
 
 
          if (mode_arg0 == VOIDmode || GET_MODE_CLASS (mode_arg0) == MODE_CC)
          if (mode_arg0 == VOIDmode || GET_MODE_CLASS (mode_arg0) == MODE_CC)
            break;
            break;
 
 
          const_arg0 = equiv_constant (folded_arg0);
          const_arg0 = equiv_constant (folded_arg0);
          const_arg1 = equiv_constant (folded_arg1);
          const_arg1 = equiv_constant (folded_arg1);
 
 
          /* If we do not now have two constants being compared, see
          /* If we do not now have two constants being compared, see
             if we can nevertheless deduce some things about the
             if we can nevertheless deduce some things about the
             comparison.  */
             comparison.  */
          if (const_arg0 == 0 || const_arg1 == 0)
          if (const_arg0 == 0 || const_arg1 == 0)
            {
            {
              if (const_arg1 != NULL)
              if (const_arg1 != NULL)
                {
                {
                  rtx cheapest_simplification;
                  rtx cheapest_simplification;
                  int cheapest_cost;
                  int cheapest_cost;
                  rtx simp_result;
                  rtx simp_result;
                  struct table_elt *p;
                  struct table_elt *p;
 
 
                  /* See if we can find an equivalent of folded_arg0
                  /* See if we can find an equivalent of folded_arg0
                     that gets us a cheaper expression, possibly a
                     that gets us a cheaper expression, possibly a
                     constant through simplifications.  */
                     constant through simplifications.  */
                  p = lookup (folded_arg0, SAFE_HASH (folded_arg0, mode_arg0),
                  p = lookup (folded_arg0, SAFE_HASH (folded_arg0, mode_arg0),
                              mode_arg0);
                              mode_arg0);
 
 
                  if (p != NULL)
                  if (p != NULL)
                    {
                    {
                      cheapest_simplification = x;
                      cheapest_simplification = x;
                      cheapest_cost = COST (x);
                      cheapest_cost = COST (x);
 
 
                      for (p = p->first_same_value; p != NULL; p = p->next_same_value)
                      for (p = p->first_same_value; p != NULL; p = p->next_same_value)
                        {
                        {
                          int cost;
                          int cost;
 
 
                          /* If the entry isn't valid, skip it.  */
                          /* If the entry isn't valid, skip it.  */
                          if (! exp_equiv_p (p->exp, p->exp, 1, false))
                          if (! exp_equiv_p (p->exp, p->exp, 1, false))
                            continue;
                            continue;
 
 
                          /* Try to simplify using this equivalence.  */
                          /* Try to simplify using this equivalence.  */
                          simp_result
                          simp_result
                            = simplify_relational_operation (code, mode,
                            = simplify_relational_operation (code, mode,
                                                             mode_arg0,
                                                             mode_arg0,
                                                             p->exp,
                                                             p->exp,
                                                             const_arg1);
                                                             const_arg1);
 
 
                          if (simp_result == NULL)
                          if (simp_result == NULL)
                            continue;
                            continue;
 
 
                          cost = COST (simp_result);
                          cost = COST (simp_result);
                          if (cost < cheapest_cost)
                          if (cost < cheapest_cost)
                            {
                            {
                              cheapest_cost = cost;
                              cheapest_cost = cost;
                              cheapest_simplification = simp_result;
                              cheapest_simplification = simp_result;
                            }
                            }
                        }
                        }
 
 
                      /* If we have a cheaper expression now, use that
                      /* If we have a cheaper expression now, use that
                         and try folding it further, from the top.  */
                         and try folding it further, from the top.  */
                      if (cheapest_simplification != x)
                      if (cheapest_simplification != x)
                        return fold_rtx (cheapest_simplification, insn);
                        return fold_rtx (cheapest_simplification, insn);
                    }
                    }
                }
                }
 
 
              /* Some addresses are known to be nonzero.  We don't know
              /* Some addresses are known to be nonzero.  We don't know
                 their sign, but equality comparisons are known.  */
                 their sign, but equality comparisons are known.  */
              if (const_arg1 == const0_rtx
              if (const_arg1 == const0_rtx
                  && nonzero_address_p (folded_arg0))
                  && nonzero_address_p (folded_arg0))
                {
                {
                  if (code == EQ)
                  if (code == EQ)
                    return false_rtx;
                    return false_rtx;
                  else if (code == NE)
                  else if (code == NE)
                    return true_rtx;
                    return true_rtx;
                }
                }
 
 
              /* See if the two operands are the same.  */
              /* See if the two operands are the same.  */
 
 
              if (folded_arg0 == folded_arg1
              if (folded_arg0 == folded_arg1
                  || (REG_P (folded_arg0)
                  || (REG_P (folded_arg0)
                      && REG_P (folded_arg1)
                      && REG_P (folded_arg1)
                      && (REG_QTY (REGNO (folded_arg0))
                      && (REG_QTY (REGNO (folded_arg0))
                          == REG_QTY (REGNO (folded_arg1))))
                          == REG_QTY (REGNO (folded_arg1))))
                  || ((p0 = lookup (folded_arg0,
                  || ((p0 = lookup (folded_arg0,
                                    SAFE_HASH (folded_arg0, mode_arg0),
                                    SAFE_HASH (folded_arg0, mode_arg0),
                                    mode_arg0))
                                    mode_arg0))
                      && (p1 = lookup (folded_arg1,
                      && (p1 = lookup (folded_arg1,
                                       SAFE_HASH (folded_arg1, mode_arg0),
                                       SAFE_HASH (folded_arg1, mode_arg0),
                                       mode_arg0))
                                       mode_arg0))
                      && p0->first_same_value == p1->first_same_value))
                      && p0->first_same_value == p1->first_same_value))
                {
                {
                  /* Sadly two equal NaNs are not equivalent.  */
                  /* Sadly two equal NaNs are not equivalent.  */
                  if (!HONOR_NANS (mode_arg0))
                  if (!HONOR_NANS (mode_arg0))
                    return ((code == EQ || code == LE || code == GE
                    return ((code == EQ || code == LE || code == GE
                             || code == LEU || code == GEU || code == UNEQ
                             || code == LEU || code == GEU || code == UNEQ
                             || code == UNLE || code == UNGE
                             || code == UNLE || code == UNGE
                             || code == ORDERED)
                             || code == ORDERED)
                            ? true_rtx : false_rtx);
                            ? true_rtx : false_rtx);
                  /* Take care for the FP compares we can resolve.  */
                  /* Take care for the FP compares we can resolve.  */
                  if (code == UNEQ || code == UNLE || code == UNGE)
                  if (code == UNEQ || code == UNLE || code == UNGE)
                    return true_rtx;
                    return true_rtx;
                  if (code == LTGT || code == LT || code == GT)
                  if (code == LTGT || code == LT || code == GT)
                    return false_rtx;
                    return false_rtx;
                }
                }
 
 
              /* If FOLDED_ARG0 is a register, see if the comparison we are
              /* If FOLDED_ARG0 is a register, see if the comparison we are
                 doing now is either the same as we did before or the reverse
                 doing now is either the same as we did before or the reverse
                 (we only check the reverse if not floating-point).  */
                 (we only check the reverse if not floating-point).  */
              else if (REG_P (folded_arg0))
              else if (REG_P (folded_arg0))
                {
                {
                  int qty = REG_QTY (REGNO (folded_arg0));
                  int qty = REG_QTY (REGNO (folded_arg0));
 
 
                  if (REGNO_QTY_VALID_P (REGNO (folded_arg0)))
                  if (REGNO_QTY_VALID_P (REGNO (folded_arg0)))
                    {
                    {
                      struct qty_table_elem *ent = &qty_table[qty];
                      struct qty_table_elem *ent = &qty_table[qty];
 
 
                      if ((comparison_dominates_p (ent->comparison_code, code)
                      if ((comparison_dominates_p (ent->comparison_code, code)
                           || (! FLOAT_MODE_P (mode_arg0)
                           || (! FLOAT_MODE_P (mode_arg0)
                               && comparison_dominates_p (ent->comparison_code,
                               && comparison_dominates_p (ent->comparison_code,
                                                          reverse_condition (code))))
                                                          reverse_condition (code))))
                          && (rtx_equal_p (ent->comparison_const, folded_arg1)
                          && (rtx_equal_p (ent->comparison_const, folded_arg1)
                              || (const_arg1
                              || (const_arg1
                                  && rtx_equal_p (ent->comparison_const,
                                  && rtx_equal_p (ent->comparison_const,
                                                  const_arg1))
                                                  const_arg1))
                              || (REG_P (folded_arg1)
                              || (REG_P (folded_arg1)
                                  && (REG_QTY (REGNO (folded_arg1)) == ent->comparison_qty))))
                                  && (REG_QTY (REGNO (folded_arg1)) == ent->comparison_qty))))
                        return (comparison_dominates_p (ent->comparison_code, code)
                        return (comparison_dominates_p (ent->comparison_code, code)
                                ? true_rtx : false_rtx);
                                ? true_rtx : false_rtx);
                    }
                    }
                }
                }
            }
            }
        }
        }
 
 
      /* If we are comparing against zero, see if the first operand is
      /* If we are comparing against zero, see if the first operand is
         equivalent to an IOR with a constant.  If so, we may be able to
         equivalent to an IOR with a constant.  If so, we may be able to
         determine the result of this comparison.  */
         determine the result of this comparison.  */
 
 
      if (const_arg1 == const0_rtx)
      if (const_arg1 == const0_rtx)
        {
        {
          rtx y = lookup_as_function (folded_arg0, IOR);
          rtx y = lookup_as_function (folded_arg0, IOR);
          rtx inner_const;
          rtx inner_const;
 
 
          if (y != 0
          if (y != 0
              && (inner_const = equiv_constant (XEXP (y, 1))) != 0
              && (inner_const = equiv_constant (XEXP (y, 1))) != 0
              && GET_CODE (inner_const) == CONST_INT
              && GET_CODE (inner_const) == CONST_INT
              && INTVAL (inner_const) != 0)
              && INTVAL (inner_const) != 0)
            {
            {
              int sign_bitnum = GET_MODE_BITSIZE (mode_arg0) - 1;
              int sign_bitnum = GET_MODE_BITSIZE (mode_arg0) - 1;
              int has_sign = (HOST_BITS_PER_WIDE_INT >= sign_bitnum
              int has_sign = (HOST_BITS_PER_WIDE_INT >= sign_bitnum
                              && (INTVAL (inner_const)
                              && (INTVAL (inner_const)
                                  & ((HOST_WIDE_INT) 1 << sign_bitnum)));
                                  & ((HOST_WIDE_INT) 1 << sign_bitnum)));
              rtx true_rtx = const_true_rtx, false_rtx = const0_rtx;
              rtx true_rtx = const_true_rtx, false_rtx = const0_rtx;
 
 
#ifdef FLOAT_STORE_FLAG_VALUE
#ifdef FLOAT_STORE_FLAG_VALUE
              if (SCALAR_FLOAT_MODE_P (mode))
              if (SCALAR_FLOAT_MODE_P (mode))
                {
                {
                  true_rtx = (CONST_DOUBLE_FROM_REAL_VALUE
                  true_rtx = (CONST_DOUBLE_FROM_REAL_VALUE
                          (FLOAT_STORE_FLAG_VALUE (mode), mode));
                          (FLOAT_STORE_FLAG_VALUE (mode), mode));
                  false_rtx = CONST0_RTX (mode);
                  false_rtx = CONST0_RTX (mode);
                }
                }
#endif
#endif
 
 
              switch (code)
              switch (code)
                {
                {
                case EQ:
                case EQ:
                  return false_rtx;
                  return false_rtx;
                case NE:
                case NE:
                  return true_rtx;
                  return true_rtx;
                case LT:  case LE:
                case LT:  case LE:
                  if (has_sign)
                  if (has_sign)
                    return true_rtx;
                    return true_rtx;
                  break;
                  break;
                case GT:  case GE:
                case GT:  case GE:
                  if (has_sign)
                  if (has_sign)
                    return false_rtx;
                    return false_rtx;
                  break;
                  break;
                default:
                default:
                  break;
                  break;
                }
                }
            }
            }
        }
        }
 
 
      {
      {
        rtx op0 = const_arg0 ? const_arg0 : folded_arg0;
        rtx op0 = const_arg0 ? const_arg0 : folded_arg0;
        rtx op1 = const_arg1 ? const_arg1 : folded_arg1;
        rtx op1 = const_arg1 ? const_arg1 : folded_arg1;
        new = simplify_relational_operation (code, mode, mode_arg0, op0, op1);
        new = simplify_relational_operation (code, mode, mode_arg0, op0, op1);
      }
      }
      break;
      break;
 
 
    case RTX_BIN_ARITH:
    case RTX_BIN_ARITH:
    case RTX_COMM_ARITH:
    case RTX_COMM_ARITH:
      switch (code)
      switch (code)
        {
        {
        case PLUS:
        case PLUS:
          /* If the second operand is a LABEL_REF, see if the first is a MINUS
          /* If the second operand is a LABEL_REF, see if the first is a MINUS
             with that LABEL_REF as its second operand.  If so, the result is
             with that LABEL_REF as its second operand.  If so, the result is
             the first operand of that MINUS.  This handles switches with an
             the first operand of that MINUS.  This handles switches with an
             ADDR_DIFF_VEC table.  */
             ADDR_DIFF_VEC table.  */
          if (const_arg1 && GET_CODE (const_arg1) == LABEL_REF)
          if (const_arg1 && GET_CODE (const_arg1) == LABEL_REF)
            {
            {
              rtx y
              rtx y
                = GET_CODE (folded_arg0) == MINUS ? folded_arg0
                = GET_CODE (folded_arg0) == MINUS ? folded_arg0
                : lookup_as_function (folded_arg0, MINUS);
                : lookup_as_function (folded_arg0, MINUS);
 
 
              if (y != 0 && GET_CODE (XEXP (y, 1)) == LABEL_REF
              if (y != 0 && GET_CODE (XEXP (y, 1)) == LABEL_REF
                  && XEXP (XEXP (y, 1), 0) == XEXP (const_arg1, 0))
                  && XEXP (XEXP (y, 1), 0) == XEXP (const_arg1, 0))
                return XEXP (y, 0);
                return XEXP (y, 0);
 
 
              /* Now try for a CONST of a MINUS like the above.  */
              /* Now try for a CONST of a MINUS like the above.  */
              if ((y = (GET_CODE (folded_arg0) == CONST ? folded_arg0
              if ((y = (GET_CODE (folded_arg0) == CONST ? folded_arg0
                        : lookup_as_function (folded_arg0, CONST))) != 0
                        : lookup_as_function (folded_arg0, CONST))) != 0
                  && GET_CODE (XEXP (y, 0)) == MINUS
                  && GET_CODE (XEXP (y, 0)) == MINUS
                  && GET_CODE (XEXP (XEXP (y, 0), 1)) == LABEL_REF
                  && GET_CODE (XEXP (XEXP (y, 0), 1)) == LABEL_REF
                  && XEXP (XEXP (XEXP (y, 0), 1), 0) == XEXP (const_arg1, 0))
                  && XEXP (XEXP (XEXP (y, 0), 1), 0) == XEXP (const_arg1, 0))
                return XEXP (XEXP (y, 0), 0);
                return XEXP (XEXP (y, 0), 0);
            }
            }
 
 
          /* Likewise if the operands are in the other order.  */
          /* Likewise if the operands are in the other order.  */
          if (const_arg0 && GET_CODE (const_arg0) == LABEL_REF)
          if (const_arg0 && GET_CODE (const_arg0) == LABEL_REF)
            {
            {
              rtx y
              rtx y
                = GET_CODE (folded_arg1) == MINUS ? folded_arg1
                = GET_CODE (folded_arg1) == MINUS ? folded_arg1
                : lookup_as_function (folded_arg1, MINUS);
                : lookup_as_function (folded_arg1, MINUS);
 
 
              if (y != 0 && GET_CODE (XEXP (y, 1)) == LABEL_REF
              if (y != 0 && GET_CODE (XEXP (y, 1)) == LABEL_REF
                  && XEXP (XEXP (y, 1), 0) == XEXP (const_arg0, 0))
                  && XEXP (XEXP (y, 1), 0) == XEXP (const_arg0, 0))
                return XEXP (y, 0);
                return XEXP (y, 0);
 
 
              /* Now try for a CONST of a MINUS like the above.  */
              /* Now try for a CONST of a MINUS like the above.  */
              if ((y = (GET_CODE (folded_arg1) == CONST ? folded_arg1
              if ((y = (GET_CODE (folded_arg1) == CONST ? folded_arg1
                        : lookup_as_function (folded_arg1, CONST))) != 0
                        : lookup_as_function (folded_arg1, CONST))) != 0
                  && GET_CODE (XEXP (y, 0)) == MINUS
                  && GET_CODE (XEXP (y, 0)) == MINUS
                  && GET_CODE (XEXP (XEXP (y, 0), 1)) == LABEL_REF
                  && GET_CODE (XEXP (XEXP (y, 0), 1)) == LABEL_REF
                  && XEXP (XEXP (XEXP (y, 0), 1), 0) == XEXP (const_arg0, 0))
                  && XEXP (XEXP (XEXP (y, 0), 1), 0) == XEXP (const_arg0, 0))
                return XEXP (XEXP (y, 0), 0);
                return XEXP (XEXP (y, 0), 0);
            }
            }
 
 
          /* If second operand is a register equivalent to a negative
          /* If second operand is a register equivalent to a negative
             CONST_INT, see if we can find a register equivalent to the
             CONST_INT, see if we can find a register equivalent to the
             positive constant.  Make a MINUS if so.  Don't do this for
             positive constant.  Make a MINUS if so.  Don't do this for
             a non-negative constant since we might then alternate between
             a non-negative constant since we might then alternate between
             choosing positive and negative constants.  Having the positive
             choosing positive and negative constants.  Having the positive
             constant previously-used is the more common case.  Be sure
             constant previously-used is the more common case.  Be sure
             the resulting constant is non-negative; if const_arg1 were
             the resulting constant is non-negative; if const_arg1 were
             the smallest negative number this would overflow: depending
             the smallest negative number this would overflow: depending
             on the mode, this would either just be the same value (and
             on the mode, this would either just be the same value (and
             hence not save anything) or be incorrect.  */
             hence not save anything) or be incorrect.  */
          if (const_arg1 != 0 && GET_CODE (const_arg1) == CONST_INT
          if (const_arg1 != 0 && GET_CODE (const_arg1) == CONST_INT
              && INTVAL (const_arg1) < 0
              && INTVAL (const_arg1) < 0
              /* This used to test
              /* This used to test
 
 
                 -INTVAL (const_arg1) >= 0
                 -INTVAL (const_arg1) >= 0
 
 
                 But The Sun V5.0 compilers mis-compiled that test.  So
                 But The Sun V5.0 compilers mis-compiled that test.  So
                 instead we test for the problematic value in a more direct
                 instead we test for the problematic value in a more direct
                 manner and hope the Sun compilers get it correct.  */
                 manner and hope the Sun compilers get it correct.  */
              && INTVAL (const_arg1) !=
              && INTVAL (const_arg1) !=
                ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1))
                ((HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1))
              && REG_P (folded_arg1))
              && REG_P (folded_arg1))
            {
            {
              rtx new_const = GEN_INT (-INTVAL (const_arg1));
              rtx new_const = GEN_INT (-INTVAL (const_arg1));
              struct table_elt *p
              struct table_elt *p
                = lookup (new_const, SAFE_HASH (new_const, mode), mode);
                = lookup (new_const, SAFE_HASH (new_const, mode), mode);
 
 
              if (p)
              if (p)
                for (p = p->first_same_value; p; p = p->next_same_value)
                for (p = p->first_same_value; p; p = p->next_same_value)
                  if (REG_P (p->exp))
                  if (REG_P (p->exp))
                    return simplify_gen_binary (MINUS, mode, folded_arg0,
                    return simplify_gen_binary (MINUS, mode, folded_arg0,
                                                canon_reg (p->exp, NULL_RTX));
                                                canon_reg (p->exp, NULL_RTX));
            }
            }
          goto from_plus;
          goto from_plus;
 
 
        case MINUS:
        case MINUS:
          /* If we have (MINUS Y C), see if Y is known to be (PLUS Z C2).
          /* If we have (MINUS Y C), see if Y is known to be (PLUS Z C2).
             If so, produce (PLUS Z C2-C).  */
             If so, produce (PLUS Z C2-C).  */
          if (const_arg1 != 0 && GET_CODE (const_arg1) == CONST_INT)
          if (const_arg1 != 0 && GET_CODE (const_arg1) == CONST_INT)
            {
            {
              rtx y = lookup_as_function (XEXP (x, 0), PLUS);
              rtx y = lookup_as_function (XEXP (x, 0), PLUS);
              if (y && GET_CODE (XEXP (y, 1)) == CONST_INT)
              if (y && GET_CODE (XEXP (y, 1)) == CONST_INT)
                return fold_rtx (plus_constant (copy_rtx (y),
                return fold_rtx (plus_constant (copy_rtx (y),
                                                -INTVAL (const_arg1)),
                                                -INTVAL (const_arg1)),
                                 NULL_RTX);
                                 NULL_RTX);
            }
            }
 
 
          /* Fall through.  */
          /* Fall through.  */
 
 
        from_plus:
        from_plus:
        case SMIN:    case SMAX:      case UMIN:    case UMAX:
        case SMIN:    case SMAX:      case UMIN:    case UMAX:
        case IOR:     case AND:       case XOR:
        case IOR:     case AND:       case XOR:
        case MULT:
        case MULT:
        case ASHIFT:  case LSHIFTRT:  case ASHIFTRT:
        case ASHIFT:  case LSHIFTRT:  case ASHIFTRT:
          /* If we have (<op> <reg> <const_int>) for an associative OP and REG
          /* If we have (<op> <reg> <const_int>) for an associative OP and REG
             is known to be of similar form, we may be able to replace the
             is known to be of similar form, we may be able to replace the
             operation with a combined operation.  This may eliminate the
             operation with a combined operation.  This may eliminate the
             intermediate operation if every use is simplified in this way.
             intermediate operation if every use is simplified in this way.
             Note that the similar optimization done by combine.c only works
             Note that the similar optimization done by combine.c only works
             if the intermediate operation's result has only one reference.  */
             if the intermediate operation's result has only one reference.  */
 
 
          if (REG_P (folded_arg0)
          if (REG_P (folded_arg0)
              && const_arg1 && GET_CODE (const_arg1) == CONST_INT)
              && const_arg1 && GET_CODE (const_arg1) == CONST_INT)
            {
            {
              int is_shift
              int is_shift
                = (code == ASHIFT || code == ASHIFTRT || code == LSHIFTRT);
                = (code == ASHIFT || code == ASHIFTRT || code == LSHIFTRT);
              rtx y, inner_const, new_const;
              rtx y, inner_const, new_const;
              enum rtx_code associate_code;
              enum rtx_code associate_code;
 
 
              if (is_shift
              if (is_shift
                  && (INTVAL (const_arg1) >= GET_MODE_BITSIZE (mode)
                  && (INTVAL (const_arg1) >= GET_MODE_BITSIZE (mode)
                      || INTVAL (const_arg1) < 0))
                      || INTVAL (const_arg1) < 0))
                {
                {
                  if (SHIFT_COUNT_TRUNCATED)
                  if (SHIFT_COUNT_TRUNCATED)
                    const_arg1 = GEN_INT (INTVAL (const_arg1)
                    const_arg1 = GEN_INT (INTVAL (const_arg1)
                                          & (GET_MODE_BITSIZE (mode) - 1));
                                          & (GET_MODE_BITSIZE (mode) - 1));
                  else
                  else
                    break;
                    break;
                }
                }
 
 
              y = lookup_as_function (folded_arg0, code);
              y = lookup_as_function (folded_arg0, code);
              if (y == 0)
              if (y == 0)
                break;
                break;
 
 
              /* If we have compiled a statement like
              /* If we have compiled a statement like
                 "if (x == (x & mask1))", and now are looking at
                 "if (x == (x & mask1))", and now are looking at
                 "x & mask2", we will have a case where the first operand
                 "x & mask2", we will have a case where the first operand
                 of Y is the same as our first operand.  Unless we detect
                 of Y is the same as our first operand.  Unless we detect
                 this case, an infinite loop will result.  */
                 this case, an infinite loop will result.  */
              if (XEXP (y, 0) == folded_arg0)
              if (XEXP (y, 0) == folded_arg0)
                break;
                break;
 
 
              inner_const = equiv_constant (fold_rtx (XEXP (y, 1), 0));
              inner_const = equiv_constant (fold_rtx (XEXP (y, 1), 0));
              if (!inner_const || GET_CODE (inner_const) != CONST_INT)
              if (!inner_const || GET_CODE (inner_const) != CONST_INT)
                break;
                break;
 
 
              /* Don't associate these operations if they are a PLUS with the
              /* Don't associate these operations if they are a PLUS with the
                 same constant and it is a power of two.  These might be doable
                 same constant and it is a power of two.  These might be doable
                 with a pre- or post-increment.  Similarly for two subtracts of
                 with a pre- or post-increment.  Similarly for two subtracts of
                 identical powers of two with post decrement.  */
                 identical powers of two with post decrement.  */
 
 
              if (code == PLUS && const_arg1 == inner_const
              if (code == PLUS && const_arg1 == inner_const
                  && ((HAVE_PRE_INCREMENT
                  && ((HAVE_PRE_INCREMENT
                          && exact_log2 (INTVAL (const_arg1)) >= 0)
                          && exact_log2 (INTVAL (const_arg1)) >= 0)
                      || (HAVE_POST_INCREMENT
                      || (HAVE_POST_INCREMENT
                          && exact_log2 (INTVAL (const_arg1)) >= 0)
                          && exact_log2 (INTVAL (const_arg1)) >= 0)
                      || (HAVE_PRE_DECREMENT
                      || (HAVE_PRE_DECREMENT
                          && exact_log2 (- INTVAL (const_arg1)) >= 0)
                          && exact_log2 (- INTVAL (const_arg1)) >= 0)
                      || (HAVE_POST_DECREMENT
                      || (HAVE_POST_DECREMENT
                          && exact_log2 (- INTVAL (const_arg1)) >= 0)))
                          && exact_log2 (- INTVAL (const_arg1)) >= 0)))
                break;
                break;
 
 
              if (is_shift
              if (is_shift
                  && (INTVAL (inner_const) >= GET_MODE_BITSIZE (mode)
                  && (INTVAL (inner_const) >= GET_MODE_BITSIZE (mode)
                      || INTVAL (inner_const) < 0))
                      || INTVAL (inner_const) < 0))
                {
                {
                  if (SHIFT_COUNT_TRUNCATED)
                  if (SHIFT_COUNT_TRUNCATED)
                    inner_const = GEN_INT (INTVAL (inner_const)
                    inner_const = GEN_INT (INTVAL (inner_const)
                                           & (GET_MODE_BITSIZE (mode) - 1));
                                           & (GET_MODE_BITSIZE (mode) - 1));
                  else
                  else
                    break;
                    break;
                }
                }
 
 
              /* Compute the code used to compose the constants.  For example,
              /* Compute the code used to compose the constants.  For example,
                 A-C1-C2 is A-(C1 + C2), so if CODE == MINUS, we want PLUS.  */
                 A-C1-C2 is A-(C1 + C2), so if CODE == MINUS, we want PLUS.  */
 
 
              associate_code = (is_shift || code == MINUS ? PLUS : code);
              associate_code = (is_shift || code == MINUS ? PLUS : code);
 
 
              new_const = simplify_binary_operation (associate_code, mode,
              new_const = simplify_binary_operation (associate_code, mode,
                                                     const_arg1, inner_const);
                                                     const_arg1, inner_const);
 
 
              if (new_const == 0)
              if (new_const == 0)
                break;
                break;
 
 
              /* If we are associating shift operations, don't let this
              /* If we are associating shift operations, don't let this
                 produce a shift of the size of the object or larger.
                 produce a shift of the size of the object or larger.
                 This could occur when we follow a sign-extend by a right
                 This could occur when we follow a sign-extend by a right
                 shift on a machine that does a sign-extend as a pair
                 shift on a machine that does a sign-extend as a pair
                 of shifts.  */
                 of shifts.  */
 
 
              if (is_shift
              if (is_shift
                  && GET_CODE (new_const) == CONST_INT
                  && GET_CODE (new_const) == CONST_INT
                  && INTVAL (new_const) >= GET_MODE_BITSIZE (mode))
                  && INTVAL (new_const) >= GET_MODE_BITSIZE (mode))
                {
                {
                  /* As an exception, we can turn an ASHIFTRT of this
                  /* As an exception, we can turn an ASHIFTRT of this
                     form into a shift of the number of bits - 1.  */
                     form into a shift of the number of bits - 1.  */
                  if (code == ASHIFTRT)
                  if (code == ASHIFTRT)
                    new_const = GEN_INT (GET_MODE_BITSIZE (mode) - 1);
                    new_const = GEN_INT (GET_MODE_BITSIZE (mode) - 1);
                  else if (!side_effects_p (XEXP (y, 0)))
                  else if (!side_effects_p (XEXP (y, 0)))
                    return CONST0_RTX (mode);
                    return CONST0_RTX (mode);
                  else
                  else
                    break;
                    break;
                }
                }
 
 
              y = copy_rtx (XEXP (y, 0));
              y = copy_rtx (XEXP (y, 0));
 
 
              /* If Y contains our first operand (the most common way this
              /* If Y contains our first operand (the most common way this
                 can happen is if Y is a MEM), we would do into an infinite
                 can happen is if Y is a MEM), we would do into an infinite
                 loop if we tried to fold it.  So don't in that case.  */
                 loop if we tried to fold it.  So don't in that case.  */
 
 
              if (! reg_mentioned_p (folded_arg0, y))
              if (! reg_mentioned_p (folded_arg0, y))
                y = fold_rtx (y, insn);
                y = fold_rtx (y, insn);
 
 
              return simplify_gen_binary (code, mode, y, new_const);
              return simplify_gen_binary (code, mode, y, new_const);
            }
            }
          break;
          break;
 
 
        case DIV:       case UDIV:
        case DIV:       case UDIV:
          /* ??? The associative optimization performed immediately above is
          /* ??? The associative optimization performed immediately above is
             also possible for DIV and UDIV using associate_code of MULT.
             also possible for DIV and UDIV using associate_code of MULT.
             However, we would need extra code to verify that the
             However, we would need extra code to verify that the
             multiplication does not overflow, that is, there is no overflow
             multiplication does not overflow, that is, there is no overflow
             in the calculation of new_const.  */
             in the calculation of new_const.  */
          break;
          break;
 
 
        default:
        default:
          break;
          break;
        }
        }
 
 
      new = simplify_binary_operation (code, mode,
      new = simplify_binary_operation (code, mode,
                                       const_arg0 ? const_arg0 : folded_arg0,
                                       const_arg0 ? const_arg0 : folded_arg0,
                                       const_arg1 ? const_arg1 : folded_arg1);
                                       const_arg1 ? const_arg1 : folded_arg1);
      break;
      break;
 
 
    case RTX_OBJ:
    case RTX_OBJ:
      /* (lo_sum (high X) X) is simply X.  */
      /* (lo_sum (high X) X) is simply X.  */
      if (code == LO_SUM && const_arg0 != 0
      if (code == LO_SUM && const_arg0 != 0
          && GET_CODE (const_arg0) == HIGH
          && GET_CODE (const_arg0) == HIGH
          && rtx_equal_p (XEXP (const_arg0, 0), const_arg1))
          && rtx_equal_p (XEXP (const_arg0, 0), const_arg1))
        return const_arg1;
        return const_arg1;
      break;
      break;
 
 
    case RTX_TERNARY:
    case RTX_TERNARY:
    case RTX_BITFIELD_OPS:
    case RTX_BITFIELD_OPS:
      new = simplify_ternary_operation (code, mode, mode_arg0,
      new = simplify_ternary_operation (code, mode, mode_arg0,
                                        const_arg0 ? const_arg0 : folded_arg0,
                                        const_arg0 ? const_arg0 : folded_arg0,
                                        const_arg1 ? const_arg1 : folded_arg1,
                                        const_arg1 ? const_arg1 : folded_arg1,
                                        const_arg2 ? const_arg2 : XEXP (x, 2));
                                        const_arg2 ? const_arg2 : XEXP (x, 2));
      break;
      break;
 
 
    default:
    default:
      break;
      break;
    }
    }
 
 
  return new ? new : x;
  return new ? new : x;
}
}


/* Return a constant value currently equivalent to X.
/* Return a constant value currently equivalent to X.
   Return 0 if we don't know one.  */
   Return 0 if we don't know one.  */
 
 
static rtx
static rtx
equiv_constant (rtx x)
equiv_constant (rtx x)
{
{
  if (REG_P (x)
  if (REG_P (x)
      && REGNO_QTY_VALID_P (REGNO (x)))
      && REGNO_QTY_VALID_P (REGNO (x)))
    {
    {
      int x_q = REG_QTY (REGNO (x));
      int x_q = REG_QTY (REGNO (x));
      struct qty_table_elem *x_ent = &qty_table[x_q];
      struct qty_table_elem *x_ent = &qty_table[x_q];
 
 
      if (x_ent->const_rtx)
      if (x_ent->const_rtx)
        x = gen_lowpart (GET_MODE (x), x_ent->const_rtx);
        x = gen_lowpart (GET_MODE (x), x_ent->const_rtx);
    }
    }
 
 
  if (x == 0 || CONSTANT_P (x))
  if (x == 0 || CONSTANT_P (x))
    return x;
    return x;
 
 
  /* If X is a MEM, try to fold it outside the context of any insn to see if
  /* If X is a MEM, try to fold it outside the context of any insn to see if
     it might be equivalent to a constant.  That handles the case where it
     it might be equivalent to a constant.  That handles the case where it
     is a constant-pool reference.  Then try to look it up in the hash table
     is a constant-pool reference.  Then try to look it up in the hash table
     in case it is something whose value we have seen before.  */
     in case it is something whose value we have seen before.  */
 
 
  if (MEM_P (x))
  if (MEM_P (x))
    {
    {
      struct table_elt *elt;
      struct table_elt *elt;
 
 
      x = fold_rtx (x, NULL_RTX);
      x = fold_rtx (x, NULL_RTX);
      if (CONSTANT_P (x))
      if (CONSTANT_P (x))
        return x;
        return x;
 
 
      elt = lookup (x, SAFE_HASH (x, GET_MODE (x)), GET_MODE (x));
      elt = lookup (x, SAFE_HASH (x, GET_MODE (x)), GET_MODE (x));
      if (elt == 0)
      if (elt == 0)
        return 0;
        return 0;
 
 
      for (elt = elt->first_same_value; elt; elt = elt->next_same_value)
      for (elt = elt->first_same_value; elt; elt = elt->next_same_value)
        if (elt->is_const && CONSTANT_P (elt->exp))
        if (elt->is_const && CONSTANT_P (elt->exp))
          return elt->exp;
          return elt->exp;
    }
    }
 
 
  return 0;
  return 0;
}
}


/* Given INSN, a jump insn, PATH_TAKEN indicates if we are following the "taken"
/* Given INSN, a jump insn, PATH_TAKEN indicates if we are following the "taken"
   branch.  It will be zero if not.
   branch.  It will be zero if not.
 
 
   In certain cases, this can cause us to add an equivalence.  For example,
   In certain cases, this can cause us to add an equivalence.  For example,
   if we are following the taken case of
   if we are following the taken case of
        if (i == 2)
        if (i == 2)
   we can add the fact that `i' and '2' are now equivalent.
   we can add the fact that `i' and '2' are now equivalent.
 
 
   In any case, we can record that this comparison was passed.  If the same
   In any case, we can record that this comparison was passed.  If the same
   comparison is seen later, we will know its value.  */
   comparison is seen later, we will know its value.  */
 
 
static void
static void
record_jump_equiv (rtx insn, int taken)
record_jump_equiv (rtx insn, int taken)
{
{
  int cond_known_true;
  int cond_known_true;
  rtx op0, op1;
  rtx op0, op1;
  rtx set;
  rtx set;
  enum machine_mode mode, mode0, mode1;
  enum machine_mode mode, mode0, mode1;
  int reversed_nonequality = 0;
  int reversed_nonequality = 0;
  enum rtx_code code;
  enum rtx_code code;
 
 
  /* Ensure this is the right kind of insn.  */
  /* Ensure this is the right kind of insn.  */
  if (! any_condjump_p (insn))
  if (! any_condjump_p (insn))
    return;
    return;
  set = pc_set (insn);
  set = pc_set (insn);
 
 
  /* See if this jump condition is known true or false.  */
  /* See if this jump condition is known true or false.  */
  if (taken)
  if (taken)
    cond_known_true = (XEXP (SET_SRC (set), 2) == pc_rtx);
    cond_known_true = (XEXP (SET_SRC (set), 2) == pc_rtx);
  else
  else
    cond_known_true = (XEXP (SET_SRC (set), 1) == pc_rtx);
    cond_known_true = (XEXP (SET_SRC (set), 1) == pc_rtx);
 
 
  /* Get the type of comparison being done and the operands being compared.
  /* Get the type of comparison being done and the operands being compared.
     If we had to reverse a non-equality condition, record that fact so we
     If we had to reverse a non-equality condition, record that fact so we
     know that it isn't valid for floating-point.  */
     know that it isn't valid for floating-point.  */
  code = GET_CODE (XEXP (SET_SRC (set), 0));
  code = GET_CODE (XEXP (SET_SRC (set), 0));
  op0 = fold_rtx (XEXP (XEXP (SET_SRC (set), 0), 0), insn);
  op0 = fold_rtx (XEXP (XEXP (SET_SRC (set), 0), 0), insn);
  op1 = fold_rtx (XEXP (XEXP (SET_SRC (set), 0), 1), insn);
  op1 = fold_rtx (XEXP (XEXP (SET_SRC (set), 0), 1), insn);
 
 
  code = find_comparison_args (code, &op0, &op1, &mode0, &mode1);
  code = find_comparison_args (code, &op0, &op1, &mode0, &mode1);
 
 
  /* If the mode is a MODE_CC mode, we don't know what kinds of things
  /* If the mode is a MODE_CC mode, we don't know what kinds of things
     are being compared, so we can't do anything with this
     are being compared, so we can't do anything with this
     comparison.  */
     comparison.  */
 
 
  if (GET_MODE_CLASS (mode0) == MODE_CC)
  if (GET_MODE_CLASS (mode0) == MODE_CC)
    return;
    return;
 
 
  if (! cond_known_true)
  if (! cond_known_true)
    {
    {
      code = reversed_comparison_code_parts (code, op0, op1, insn);
      code = reversed_comparison_code_parts (code, op0, op1, insn);
 
 
      /* Don't remember if we can't find the inverse.  */
      /* Don't remember if we can't find the inverse.  */
      if (code == UNKNOWN)
      if (code == UNKNOWN)
        return;
        return;
    }
    }
 
 
  /* The mode is the mode of the non-constant.  */
  /* The mode is the mode of the non-constant.  */
  mode = mode0;
  mode = mode0;
  if (mode1 != VOIDmode)
  if (mode1 != VOIDmode)
    mode = mode1;
    mode = mode1;
 
 
  record_jump_cond (code, mode, op0, op1, reversed_nonequality);
  record_jump_cond (code, mode, op0, op1, reversed_nonequality);
}
}
 
 
/* Yet another form of subreg creation.  In this case, we want something in
/* Yet another form of subreg creation.  In this case, we want something in
   MODE, and we should assume OP has MODE iff it is naturally modeless.  */
   MODE, and we should assume OP has MODE iff it is naturally modeless.  */
 
 
static rtx
static rtx
record_jump_cond_subreg (enum machine_mode mode, rtx op)
record_jump_cond_subreg (enum machine_mode mode, rtx op)
{
{
  enum machine_mode op_mode = GET_MODE (op);
  enum machine_mode op_mode = GET_MODE (op);
  if (op_mode == mode || op_mode == VOIDmode)
  if (op_mode == mode || op_mode == VOIDmode)
    return op;
    return op;
  return lowpart_subreg (mode, op, op_mode);
  return lowpart_subreg (mode, op, op_mode);
}
}
 
 
/* We know that comparison CODE applied to OP0 and OP1 in MODE is true.
/* We know that comparison CODE applied to OP0 and OP1 in MODE is true.
   REVERSED_NONEQUALITY is nonzero if CODE had to be swapped.
   REVERSED_NONEQUALITY is nonzero if CODE had to be swapped.
   Make any useful entries we can with that information.  Called from
   Make any useful entries we can with that information.  Called from
   above function and called recursively.  */
   above function and called recursively.  */
 
 
static void
static void
record_jump_cond (enum rtx_code code, enum machine_mode mode, rtx op0,
record_jump_cond (enum rtx_code code, enum machine_mode mode, rtx op0,
                  rtx op1, int reversed_nonequality)
                  rtx op1, int reversed_nonequality)
{
{
  unsigned op0_hash, op1_hash;
  unsigned op0_hash, op1_hash;
  int op0_in_memory, op1_in_memory;
  int op0_in_memory, op1_in_memory;
  struct table_elt *op0_elt, *op1_elt;
  struct table_elt *op0_elt, *op1_elt;
 
 
  /* If OP0 and OP1 are known equal, and either is a paradoxical SUBREG,
  /* If OP0 and OP1 are known equal, and either is a paradoxical SUBREG,
     we know that they are also equal in the smaller mode (this is also
     we know that they are also equal in the smaller mode (this is also
     true for all smaller modes whether or not there is a SUBREG, but
     true for all smaller modes whether or not there is a SUBREG, but
     is not worth testing for with no SUBREG).  */
     is not worth testing for with no SUBREG).  */
 
 
  /* Note that GET_MODE (op0) may not equal MODE.  */
  /* Note that GET_MODE (op0) may not equal MODE.  */
  if (code == EQ && GET_CODE (op0) == SUBREG
  if (code == EQ && GET_CODE (op0) == SUBREG
      && (GET_MODE_SIZE (GET_MODE (op0))
      && (GET_MODE_SIZE (GET_MODE (op0))
          > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0)))))
          > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0)))))
    {
    {
      enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op0));
      enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op0));
      rtx tem = record_jump_cond_subreg (inner_mode, op1);
      rtx tem = record_jump_cond_subreg (inner_mode, op1);
      if (tem)
      if (tem)
        record_jump_cond (code, mode, SUBREG_REG (op0), tem,
        record_jump_cond (code, mode, SUBREG_REG (op0), tem,
                          reversed_nonequality);
                          reversed_nonequality);
    }
    }
 
 
  if (code == EQ && GET_CODE (op1) == SUBREG
  if (code == EQ && GET_CODE (op1) == SUBREG
      && (GET_MODE_SIZE (GET_MODE (op1))
      && (GET_MODE_SIZE (GET_MODE (op1))
          > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1)))))
          > GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1)))))
    {
    {
      enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op1));
      enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op1));
      rtx tem = record_jump_cond_subreg (inner_mode, op0);
      rtx tem = record_jump_cond_subreg (inner_mode, op0);
      if (tem)
      if (tem)
        record_jump_cond (code, mode, SUBREG_REG (op1), tem,
        record_jump_cond (code, mode, SUBREG_REG (op1), tem,
                          reversed_nonequality);
                          reversed_nonequality);
    }
    }
 
 
  /* Similarly, if this is an NE comparison, and either is a SUBREG
  /* Similarly, if this is an NE comparison, and either is a SUBREG
     making a smaller mode, we know the whole thing is also NE.  */
     making a smaller mode, we know the whole thing is also NE.  */
 
 
  /* Note that GET_MODE (op0) may not equal MODE;
  /* Note that GET_MODE (op0) may not equal MODE;
     if we test MODE instead, we can get an infinite recursion
     if we test MODE instead, we can get an infinite recursion
     alternating between two modes each wider than MODE.  */
     alternating between two modes each wider than MODE.  */
 
 
  if (code == NE && GET_CODE (op0) == SUBREG
  if (code == NE && GET_CODE (op0) == SUBREG
      && subreg_lowpart_p (op0)
      && subreg_lowpart_p (op0)
      && (GET_MODE_SIZE (GET_MODE (op0))
      && (GET_MODE_SIZE (GET_MODE (op0))
          < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0)))))
          < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op0)))))
    {
    {
      enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op0));
      enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op0));
      rtx tem = record_jump_cond_subreg (inner_mode, op1);
      rtx tem = record_jump_cond_subreg (inner_mode, op1);
      if (tem)
      if (tem)
        record_jump_cond (code, mode, SUBREG_REG (op0), tem,
        record_jump_cond (code, mode, SUBREG_REG (op0), tem,
                          reversed_nonequality);
                          reversed_nonequality);
    }
    }
 
 
  if (code == NE && GET_CODE (op1) == SUBREG
  if (code == NE && GET_CODE (op1) == SUBREG
      && subreg_lowpart_p (op1)
      && subreg_lowpart_p (op1)
      && (GET_MODE_SIZE (GET_MODE (op1))
      && (GET_MODE_SIZE (GET_MODE (op1))
          < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1)))))
          < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op1)))))
    {
    {
      enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op1));
      enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op1));
      rtx tem = record_jump_cond_subreg (inner_mode, op0);
      rtx tem = record_jump_cond_subreg (inner_mode, op0);
      if (tem)
      if (tem)
        record_jump_cond (code, mode, SUBREG_REG (op1), tem,
        record_jump_cond (code, mode, SUBREG_REG (op1), tem,
                          reversed_nonequality);
                          reversed_nonequality);
    }
    }
 
 
  /* Hash both operands.  */
  /* Hash both operands.  */
 
 
  do_not_record = 0;
  do_not_record = 0;
  hash_arg_in_memory = 0;
  hash_arg_in_memory = 0;
  op0_hash = HASH (op0, mode);
  op0_hash = HASH (op0, mode);
  op0_in_memory = hash_arg_in_memory;
  op0_in_memory = hash_arg_in_memory;
 
 
  if (do_not_record)
  if (do_not_record)
    return;
    return;
 
 
  do_not_record = 0;
  do_not_record = 0;
  hash_arg_in_memory = 0;
  hash_arg_in_memory = 0;
  op1_hash = HASH (op1, mode);
  op1_hash = HASH (op1, mode);
  op1_in_memory = hash_arg_in_memory;
  op1_in_memory = hash_arg_in_memory;
 
 
  if (do_not_record)
  if (do_not_record)
    return;
    return;
 
 
  /* Look up both operands.  */
  /* Look up both operands.  */
  op0_elt = lookup (op0, op0_hash, mode);
  op0_elt = lookup (op0, op0_hash, mode);
  op1_elt = lookup (op1, op1_hash, mode);
  op1_elt = lookup (op1, op1_hash, mode);
 
 
  /* If both operands are already equivalent or if they are not in the
  /* If both operands are already equivalent or if they are not in the
     table but are identical, do nothing.  */
     table but are identical, do nothing.  */
  if ((op0_elt != 0 && op1_elt != 0
  if ((op0_elt != 0 && op1_elt != 0
       && op0_elt->first_same_value == op1_elt->first_same_value)
       && op0_elt->first_same_value == op1_elt->first_same_value)
      || op0 == op1 || rtx_equal_p (op0, op1))
      || op0 == op1 || rtx_equal_p (op0, op1))
    return;
    return;
 
 
  /* If we aren't setting two things equal all we can do is save this
  /* If we aren't setting two things equal all we can do is save this
     comparison.   Similarly if this is floating-point.  In the latter
     comparison.   Similarly if this is floating-point.  In the latter
     case, OP1 might be zero and both -0.0 and 0.0 are equal to it.
     case, OP1 might be zero and both -0.0 and 0.0 are equal to it.
     If we record the equality, we might inadvertently delete code
     If we record the equality, we might inadvertently delete code
     whose intent was to change -0 to +0.  */
     whose intent was to change -0 to +0.  */
 
 
  if (code != EQ || FLOAT_MODE_P (GET_MODE (op0)))
  if (code != EQ || FLOAT_MODE_P (GET_MODE (op0)))
    {
    {
      struct qty_table_elem *ent;
      struct qty_table_elem *ent;
      int qty;
      int qty;
 
 
      /* If we reversed a floating-point comparison, if OP0 is not a
      /* If we reversed a floating-point comparison, if OP0 is not a
         register, or if OP1 is neither a register or constant, we can't
         register, or if OP1 is neither a register or constant, we can't
         do anything.  */
         do anything.  */
 
 
      if (!REG_P (op1))
      if (!REG_P (op1))
        op1 = equiv_constant (op1);
        op1 = equiv_constant (op1);
 
 
      if ((reversed_nonequality && FLOAT_MODE_P (mode))
      if ((reversed_nonequality && FLOAT_MODE_P (mode))
          || !REG_P (op0) || op1 == 0)
          || !REG_P (op0) || op1 == 0)
        return;
        return;
 
 
      /* Put OP0 in the hash table if it isn't already.  This gives it a
      /* Put OP0 in the hash table if it isn't already.  This gives it a
         new quantity number.  */
         new quantity number.  */
      if (op0_elt == 0)
      if (op0_elt == 0)
        {
        {
          if (insert_regs (op0, NULL, 0))
          if (insert_regs (op0, NULL, 0))
            {
            {
              rehash_using_reg (op0);
              rehash_using_reg (op0);
              op0_hash = HASH (op0, mode);
              op0_hash = HASH (op0, mode);
 
 
              /* If OP0 is contained in OP1, this changes its hash code
              /* If OP0 is contained in OP1, this changes its hash code
                 as well.  Faster to rehash than to check, except
                 as well.  Faster to rehash than to check, except
                 for the simple case of a constant.  */
                 for the simple case of a constant.  */
              if (! CONSTANT_P (op1))
              if (! CONSTANT_P (op1))
                op1_hash = HASH (op1,mode);
                op1_hash = HASH (op1,mode);
            }
            }
 
 
          op0_elt = insert (op0, NULL, op0_hash, mode);
          op0_elt = insert (op0, NULL, op0_hash, mode);
          op0_elt->in_memory = op0_in_memory;
          op0_elt->in_memory = op0_in_memory;
        }
        }
 
 
      qty = REG_QTY (REGNO (op0));
      qty = REG_QTY (REGNO (op0));
      ent = &qty_table[qty];
      ent = &qty_table[qty];
 
 
      ent->comparison_code = code;
      ent->comparison_code = code;
      if (REG_P (op1))
      if (REG_P (op1))
        {
        {
          /* Look it up again--in case op0 and op1 are the same.  */
          /* Look it up again--in case op0 and op1 are the same.  */
          op1_elt = lookup (op1, op1_hash, mode);
          op1_elt = lookup (op1, op1_hash, mode);
 
 
          /* Put OP1 in the hash table so it gets a new quantity number.  */
          /* Put OP1 in the hash table so it gets a new quantity number.  */
          if (op1_elt == 0)
          if (op1_elt == 0)
            {
            {
              if (insert_regs (op1, NULL, 0))
              if (insert_regs (op1, NULL, 0))
                {
                {
                  rehash_using_reg (op1);
                  rehash_using_reg (op1);
                  op1_hash = HASH (op1, mode);
                  op1_hash = HASH (op1, mode);
                }
                }
 
 
              op1_elt = insert (op1, NULL, op1_hash, mode);
              op1_elt = insert (op1, NULL, op1_hash, mode);
              op1_elt->in_memory = op1_in_memory;
              op1_elt->in_memory = op1_in_memory;
            }
            }
 
 
          ent->comparison_const = NULL_RTX;
          ent->comparison_const = NULL_RTX;
          ent->comparison_qty = REG_QTY (REGNO (op1));
          ent->comparison_qty = REG_QTY (REGNO (op1));
        }
        }
      else
      else
        {
        {
          ent->comparison_const = op1;
          ent->comparison_const = op1;
          ent->comparison_qty = -1;
          ent->comparison_qty = -1;
        }
        }
 
 
      return;
      return;
    }
    }
 
 
  /* If either side is still missing an equivalence, make it now,
  /* If either side is still missing an equivalence, make it now,
     then merge the equivalences.  */
     then merge the equivalences.  */
 
 
  if (op0_elt == 0)
  if (op0_elt == 0)
    {
    {
      if (insert_regs (op0, NULL, 0))
      if (insert_regs (op0, NULL, 0))
        {
        {
          rehash_using_reg (op0);
          rehash_using_reg (op0);
          op0_hash = HASH (op0, mode);
          op0_hash = HASH (op0, mode);
        }
        }
 
 
      op0_elt = insert (op0, NULL, op0_hash, mode);
      op0_elt = insert (op0, NULL, op0_hash, mode);
      op0_elt->in_memory = op0_in_memory;
      op0_elt->in_memory = op0_in_memory;
    }
    }
 
 
  if (op1_elt == 0)
  if (op1_elt == 0)
    {
    {
      if (insert_regs (op1, NULL, 0))
      if (insert_regs (op1, NULL, 0))
        {
        {
          rehash_using_reg (op1);
          rehash_using_reg (op1);
          op1_hash = HASH (op1, mode);
          op1_hash = HASH (op1, mode);
        }
        }
 
 
      op1_elt = insert (op1, NULL, op1_hash, mode);
      op1_elt = insert (op1, NULL, op1_hash, mode);
      op1_elt->in_memory = op1_in_memory;
      op1_elt->in_memory = op1_in_memory;
    }
    }
 
 
  merge_equiv_classes (op0_elt, op1_elt);
  merge_equiv_classes (op0_elt, op1_elt);
}
}


/* CSE processing for one instruction.
/* CSE processing for one instruction.
   First simplify sources and addresses of all assignments
   First simplify sources and addresses of all assignments
   in the instruction, using previously-computed equivalents values.
   in the instruction, using previously-computed equivalents values.
   Then install the new sources and destinations in the table
   Then install the new sources and destinations in the table
   of available values.
   of available values.
 
 
   If LIBCALL_INSN is nonzero, don't record any equivalence made in
   If LIBCALL_INSN is nonzero, don't record any equivalence made in
   the insn.  It means that INSN is inside libcall block.  In this
   the insn.  It means that INSN is inside libcall block.  In this
   case LIBCALL_INSN is the corresponding insn with REG_LIBCALL.  */
   case LIBCALL_INSN is the corresponding insn with REG_LIBCALL.  */
 
 
/* Data on one SET contained in the instruction.  */
/* Data on one SET contained in the instruction.  */
 
 
struct set
struct set
{
{
  /* The SET rtx itself.  */
  /* The SET rtx itself.  */
  rtx rtl;
  rtx rtl;
  /* The SET_SRC of the rtx (the original value, if it is changing).  */
  /* The SET_SRC of the rtx (the original value, if it is changing).  */
  rtx src;
  rtx src;
  /* The hash-table element for the SET_SRC of the SET.  */
  /* The hash-table element for the SET_SRC of the SET.  */
  struct table_elt *src_elt;
  struct table_elt *src_elt;
  /* Hash value for the SET_SRC.  */
  /* Hash value for the SET_SRC.  */
  unsigned src_hash;
  unsigned src_hash;
  /* Hash value for the SET_DEST.  */
  /* Hash value for the SET_DEST.  */
  unsigned dest_hash;
  unsigned dest_hash;
  /* The SET_DEST, with SUBREG, etc., stripped.  */
  /* The SET_DEST, with SUBREG, etc., stripped.  */
  rtx inner_dest;
  rtx inner_dest;
  /* Nonzero if the SET_SRC is in memory.  */
  /* Nonzero if the SET_SRC is in memory.  */
  char src_in_memory;
  char src_in_memory;
  /* Nonzero if the SET_SRC contains something
  /* Nonzero if the SET_SRC contains something
     whose value cannot be predicted and understood.  */
     whose value cannot be predicted and understood.  */
  char src_volatile;
  char src_volatile;
  /* Original machine mode, in case it becomes a CONST_INT.
  /* Original machine mode, in case it becomes a CONST_INT.
     The size of this field should match the size of the mode
     The size of this field should match the size of the mode
     field of struct rtx_def (see rtl.h).  */
     field of struct rtx_def (see rtl.h).  */
  ENUM_BITFIELD(machine_mode) mode : 8;
  ENUM_BITFIELD(machine_mode) mode : 8;
  /* A constant equivalent for SET_SRC, if any.  */
  /* A constant equivalent for SET_SRC, if any.  */
  rtx src_const;
  rtx src_const;
  /* Original SET_SRC value used for libcall notes.  */
  /* Original SET_SRC value used for libcall notes.  */
  rtx orig_src;
  rtx orig_src;
  /* Hash value of constant equivalent for SET_SRC.  */
  /* Hash value of constant equivalent for SET_SRC.  */
  unsigned src_const_hash;
  unsigned src_const_hash;
  /* Table entry for constant equivalent for SET_SRC, if any.  */
  /* Table entry for constant equivalent for SET_SRC, if any.  */
  struct table_elt *src_const_elt;
  struct table_elt *src_const_elt;
  /* Table entry for the destination address.  */
  /* Table entry for the destination address.  */
  struct table_elt *dest_addr_elt;
  struct table_elt *dest_addr_elt;
};
};
 
 
static void
static void
cse_insn (rtx insn, rtx libcall_insn)
cse_insn (rtx insn, rtx libcall_insn)
{
{
  rtx x = PATTERN (insn);
  rtx x = PATTERN (insn);
  int i;
  int i;
  rtx tem;
  rtx tem;
  int n_sets = 0;
  int n_sets = 0;
 
 
#ifdef HAVE_cc0
#ifdef HAVE_cc0
  /* Records what this insn does to set CC0.  */
  /* Records what this insn does to set CC0.  */
  rtx this_insn_cc0 = 0;
  rtx this_insn_cc0 = 0;
  enum machine_mode this_insn_cc0_mode = VOIDmode;
  enum machine_mode this_insn_cc0_mode = VOIDmode;
#endif
#endif
 
 
  rtx src_eqv = 0;
  rtx src_eqv = 0;
  struct table_elt *src_eqv_elt = 0;
  struct table_elt *src_eqv_elt = 0;
  int src_eqv_volatile = 0;
  int src_eqv_volatile = 0;
  int src_eqv_in_memory = 0;
  int src_eqv_in_memory = 0;
  unsigned src_eqv_hash = 0;
  unsigned src_eqv_hash = 0;
 
 
  struct set *sets = (struct set *) 0;
  struct set *sets = (struct set *) 0;
 
 
  this_insn = insn;
  this_insn = insn;
 
 
  /* Find all the SETs and CLOBBERs in this instruction.
  /* Find all the SETs and CLOBBERs in this instruction.
     Record all the SETs in the array `set' and count them.
     Record all the SETs in the array `set' and count them.
     Also determine whether there is a CLOBBER that invalidates
     Also determine whether there is a CLOBBER that invalidates
     all memory references, or all references at varying addresses.  */
     all memory references, or all references at varying addresses.  */
 
 
  if (CALL_P (insn))
  if (CALL_P (insn))
    {
    {
      for (tem = CALL_INSN_FUNCTION_USAGE (insn); tem; tem = XEXP (tem, 1))
      for (tem = CALL_INSN_FUNCTION_USAGE (insn); tem; tem = XEXP (tem, 1))
        {
        {
          if (GET_CODE (XEXP (tem, 0)) == CLOBBER)
          if (GET_CODE (XEXP (tem, 0)) == CLOBBER)
            invalidate (SET_DEST (XEXP (tem, 0)), VOIDmode);
            invalidate (SET_DEST (XEXP (tem, 0)), VOIDmode);
          XEXP (tem, 0) = canon_reg (XEXP (tem, 0), insn);
          XEXP (tem, 0) = canon_reg (XEXP (tem, 0), insn);
        }
        }
    }
    }
 
 
  if (GET_CODE (x) == SET)
  if (GET_CODE (x) == SET)
    {
    {
      sets = alloca (sizeof (struct set));
      sets = alloca (sizeof (struct set));
      sets[0].rtl = x;
      sets[0].rtl = x;
 
 
      /* Ignore SETs that are unconditional jumps.
      /* Ignore SETs that are unconditional jumps.
         They never need cse processing, so this does not hurt.
         They never need cse processing, so this does not hurt.
         The reason is not efficiency but rather
         The reason is not efficiency but rather
         so that we can test at the end for instructions
         so that we can test at the end for instructions
         that have been simplified to unconditional jumps
         that have been simplified to unconditional jumps
         and not be misled by unchanged instructions
         and not be misled by unchanged instructions
         that were unconditional jumps to begin with.  */
         that were unconditional jumps to begin with.  */
      if (SET_DEST (x) == pc_rtx
      if (SET_DEST (x) == pc_rtx
          && GET_CODE (SET_SRC (x)) == LABEL_REF)
          && GET_CODE (SET_SRC (x)) == LABEL_REF)
        ;
        ;
 
 
      /* Don't count call-insns, (set (reg 0) (call ...)), as a set.
      /* Don't count call-insns, (set (reg 0) (call ...)), as a set.
         The hard function value register is used only once, to copy to
         The hard function value register is used only once, to copy to
         someplace else, so it isn't worth cse'ing (and on 80386 is unsafe)!
         someplace else, so it isn't worth cse'ing (and on 80386 is unsafe)!
         Ensure we invalidate the destination register.  On the 80386 no
         Ensure we invalidate the destination register.  On the 80386 no
         other code would invalidate it since it is a fixed_reg.
         other code would invalidate it since it is a fixed_reg.
         We need not check the return of apply_change_group; see canon_reg.  */
         We need not check the return of apply_change_group; see canon_reg.  */
 
 
      else if (GET_CODE (SET_SRC (x)) == CALL)
      else if (GET_CODE (SET_SRC (x)) == CALL)
        {
        {
          canon_reg (SET_SRC (x), insn);
          canon_reg (SET_SRC (x), insn);
          apply_change_group ();
          apply_change_group ();
          fold_rtx (SET_SRC (x), insn);
          fold_rtx (SET_SRC (x), insn);
          invalidate (SET_DEST (x), VOIDmode);
          invalidate (SET_DEST (x), VOIDmode);
        }
        }
      else
      else
        n_sets = 1;
        n_sets = 1;
    }
    }
  else if (GET_CODE (x) == PARALLEL)
  else if (GET_CODE (x) == PARALLEL)
    {
    {
      int lim = XVECLEN (x, 0);
      int lim = XVECLEN (x, 0);
 
 
      sets = alloca (lim * sizeof (struct set));
      sets = alloca (lim * sizeof (struct set));
 
 
      /* Find all regs explicitly clobbered in this insn,
      /* Find all regs explicitly clobbered in this insn,
         and ensure they are not replaced with any other regs
         and ensure they are not replaced with any other regs
         elsewhere in this insn.
         elsewhere in this insn.
         When a reg that is clobbered is also used for input,
         When a reg that is clobbered is also used for input,
         we should presume that that is for a reason,
         we should presume that that is for a reason,
         and we should not substitute some other register
         and we should not substitute some other register
         which is not supposed to be clobbered.
         which is not supposed to be clobbered.
         Therefore, this loop cannot be merged into the one below
         Therefore, this loop cannot be merged into the one below
         because a CALL may precede a CLOBBER and refer to the
         because a CALL may precede a CLOBBER and refer to the
         value clobbered.  We must not let a canonicalization do
         value clobbered.  We must not let a canonicalization do
         anything in that case.  */
         anything in that case.  */
      for (i = 0; i < lim; i++)
      for (i = 0; i < lim; i++)
        {
        {
          rtx y = XVECEXP (x, 0, i);
          rtx y = XVECEXP (x, 0, i);
          if (GET_CODE (y) == CLOBBER)
          if (GET_CODE (y) == CLOBBER)
            {
            {
              rtx clobbered = XEXP (y, 0);
              rtx clobbered = XEXP (y, 0);
 
 
              if (REG_P (clobbered)
              if (REG_P (clobbered)
                  || GET_CODE (clobbered) == SUBREG)
                  || GET_CODE (clobbered) == SUBREG)
                invalidate (clobbered, VOIDmode);
                invalidate (clobbered, VOIDmode);
              else if (GET_CODE (clobbered) == STRICT_LOW_PART
              else if (GET_CODE (clobbered) == STRICT_LOW_PART
                       || GET_CODE (clobbered) == ZERO_EXTRACT)
                       || GET_CODE (clobbered) == ZERO_EXTRACT)
                invalidate (XEXP (clobbered, 0), GET_MODE (clobbered));
                invalidate (XEXP (clobbered, 0), GET_MODE (clobbered));
            }
            }
        }
        }
 
 
      for (i = 0; i < lim; i++)
      for (i = 0; i < lim; i++)
        {
        {
          rtx y = XVECEXP (x, 0, i);
          rtx y = XVECEXP (x, 0, i);
          if (GET_CODE (y) == SET)
          if (GET_CODE (y) == SET)
            {
            {
              /* As above, we ignore unconditional jumps and call-insns and
              /* As above, we ignore unconditional jumps and call-insns and
                 ignore the result of apply_change_group.  */
                 ignore the result of apply_change_group.  */
              if (GET_CODE (SET_SRC (y)) == CALL)
              if (GET_CODE (SET_SRC (y)) == CALL)
                {
                {
                  canon_reg (SET_SRC (y), insn);
                  canon_reg (SET_SRC (y), insn);
                  apply_change_group ();
                  apply_change_group ();
                  fold_rtx (SET_SRC (y), insn);
                  fold_rtx (SET_SRC (y), insn);
                  invalidate (SET_DEST (y), VOIDmode);
                  invalidate (SET_DEST (y), VOIDmode);
                }
                }
              else if (SET_DEST (y) == pc_rtx
              else if (SET_DEST (y) == pc_rtx
                       && GET_CODE (SET_SRC (y)) == LABEL_REF)
                       && GET_CODE (SET_SRC (y)) == LABEL_REF)
                ;
                ;
              else
              else
                sets[n_sets++].rtl = y;
                sets[n_sets++].rtl = y;
            }
            }
          else if (GET_CODE (y) == CLOBBER)
          else if (GET_CODE (y) == CLOBBER)
            {
            {
              /* If we clobber memory, canon the address.
              /* If we clobber memory, canon the address.
                 This does nothing when a register is clobbered
                 This does nothing when a register is clobbered
                 because we have already invalidated the reg.  */
                 because we have already invalidated the reg.  */
              if (MEM_P (XEXP (y, 0)))
              if (MEM_P (XEXP (y, 0)))
                canon_reg (XEXP (y, 0), NULL_RTX);
                canon_reg (XEXP (y, 0), NULL_RTX);
            }
            }
          else if (GET_CODE (y) == USE
          else if (GET_CODE (y) == USE
                   && ! (REG_P (XEXP (y, 0))
                   && ! (REG_P (XEXP (y, 0))
                         && REGNO (XEXP (y, 0)) < FIRST_PSEUDO_REGISTER))
                         && REGNO (XEXP (y, 0)) < FIRST_PSEUDO_REGISTER))
            canon_reg (y, NULL_RTX);
            canon_reg (y, NULL_RTX);
          else if (GET_CODE (y) == CALL)
          else if (GET_CODE (y) == CALL)
            {
            {
              /* The result of apply_change_group can be ignored; see
              /* The result of apply_change_group can be ignored; see
                 canon_reg.  */
                 canon_reg.  */
              canon_reg (y, insn);
              canon_reg (y, insn);
              apply_change_group ();
              apply_change_group ();
              fold_rtx (y, insn);
              fold_rtx (y, insn);
            }
            }
        }
        }
    }
    }
  else if (GET_CODE (x) == CLOBBER)
  else if (GET_CODE (x) == CLOBBER)
    {
    {
      if (MEM_P (XEXP (x, 0)))
      if (MEM_P (XEXP (x, 0)))
        canon_reg (XEXP (x, 0), NULL_RTX);
        canon_reg (XEXP (x, 0), NULL_RTX);
    }
    }
 
 
  /* Canonicalize a USE of a pseudo register or memory location.  */
  /* Canonicalize a USE of a pseudo register or memory location.  */
  else if (GET_CODE (x) == USE
  else if (GET_CODE (x) == USE
           && ! (REG_P (XEXP (x, 0))
           && ! (REG_P (XEXP (x, 0))
                 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER))
                 && REGNO (XEXP (x, 0)) < FIRST_PSEUDO_REGISTER))
    canon_reg (XEXP (x, 0), NULL_RTX);
    canon_reg (XEXP (x, 0), NULL_RTX);
  else if (GET_CODE (x) == CALL)
  else if (GET_CODE (x) == CALL)
    {
    {
      /* The result of apply_change_group can be ignored; see canon_reg.  */
      /* The result of apply_change_group can be ignored; see canon_reg.  */
      canon_reg (x, insn);
      canon_reg (x, insn);
      apply_change_group ();
      apply_change_group ();
      fold_rtx (x, insn);
      fold_rtx (x, insn);
    }
    }
 
 
  /* Store the equivalent value in SRC_EQV, if different, or if the DEST
  /* Store the equivalent value in SRC_EQV, if different, or if the DEST
     is a STRICT_LOW_PART.  The latter condition is necessary because SRC_EQV
     is a STRICT_LOW_PART.  The latter condition is necessary because SRC_EQV
     is handled specially for this case, and if it isn't set, then there will
     is handled specially for this case, and if it isn't set, then there will
     be no equivalence for the destination.  */
     be no equivalence for the destination.  */
  if (n_sets == 1 && REG_NOTES (insn) != 0
  if (n_sets == 1 && REG_NOTES (insn) != 0
      && (tem = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0
      && (tem = find_reg_note (insn, REG_EQUAL, NULL_RTX)) != 0
      && (! rtx_equal_p (XEXP (tem, 0), SET_SRC (sets[0].rtl))
      && (! rtx_equal_p (XEXP (tem, 0), SET_SRC (sets[0].rtl))
          || GET_CODE (SET_DEST (sets[0].rtl)) == STRICT_LOW_PART))
          || GET_CODE (SET_DEST (sets[0].rtl)) == STRICT_LOW_PART))
    {
    {
      src_eqv = fold_rtx (canon_reg (XEXP (tem, 0), NULL_RTX), insn);
      src_eqv = fold_rtx (canon_reg (XEXP (tem, 0), NULL_RTX), insn);
      XEXP (tem, 0) = src_eqv;
      XEXP (tem, 0) = src_eqv;
    }
    }
 
 
  /* Canonicalize sources and addresses of destinations.
  /* Canonicalize sources and addresses of destinations.
     We do this in a separate pass to avoid problems when a MATCH_DUP is
     We do this in a separate pass to avoid problems when a MATCH_DUP is
     present in the insn pattern.  In that case, we want to ensure that
     present in the insn pattern.  In that case, we want to ensure that
     we don't break the duplicate nature of the pattern.  So we will replace
     we don't break the duplicate nature of the pattern.  So we will replace
     both operands at the same time.  Otherwise, we would fail to find an
     both operands at the same time.  Otherwise, we would fail to find an
     equivalent substitution in the loop calling validate_change below.
     equivalent substitution in the loop calling validate_change below.
 
 
     We used to suppress canonicalization of DEST if it appears in SRC,
     We used to suppress canonicalization of DEST if it appears in SRC,
     but we don't do this any more.  */
     but we don't do this any more.  */
 
 
  for (i = 0; i < n_sets; i++)
  for (i = 0; i < n_sets; i++)
    {
    {
      rtx dest = SET_DEST (sets[i].rtl);
      rtx dest = SET_DEST (sets[i].rtl);
      rtx src = SET_SRC (sets[i].rtl);
      rtx src = SET_SRC (sets[i].rtl);
      rtx new = canon_reg (src, insn);
      rtx new = canon_reg (src, insn);
 
 
      sets[i].orig_src = src;
      sets[i].orig_src = src;
      validate_change (insn, &SET_SRC (sets[i].rtl), new, 1);
      validate_change (insn, &SET_SRC (sets[i].rtl), new, 1);
 
 
      if (GET_CODE (dest) == ZERO_EXTRACT)
      if (GET_CODE (dest) == ZERO_EXTRACT)
        {
        {
          validate_change (insn, &XEXP (dest, 1),
          validate_change (insn, &XEXP (dest, 1),
                           canon_reg (XEXP (dest, 1), insn), 1);
                           canon_reg (XEXP (dest, 1), insn), 1);
          validate_change (insn, &XEXP (dest, 2),
          validate_change (insn, &XEXP (dest, 2),
                           canon_reg (XEXP (dest, 2), insn), 1);
                           canon_reg (XEXP (dest, 2), insn), 1);
        }
        }
 
 
      while (GET_CODE (dest) == SUBREG
      while (GET_CODE (dest) == SUBREG
             || GET_CODE (dest) == ZERO_EXTRACT
             || GET_CODE (dest) == ZERO_EXTRACT
             || GET_CODE (dest) == STRICT_LOW_PART)
             || GET_CODE (dest) == STRICT_LOW_PART)
        dest = XEXP (dest, 0);
        dest = XEXP (dest, 0);
 
 
      if (MEM_P (dest))
      if (MEM_P (dest))
        canon_reg (dest, insn);
        canon_reg (dest, insn);
    }
    }
 
 
  /* Now that we have done all the replacements, we can apply the change
  /* Now that we have done all the replacements, we can apply the change
     group and see if they all work.  Note that this will cause some
     group and see if they all work.  Note that this will cause some
     canonicalizations that would have worked individually not to be applied
     canonicalizations that would have worked individually not to be applied
     because some other canonicalization didn't work, but this should not
     because some other canonicalization didn't work, but this should not
     occur often.
     occur often.
 
 
     The result of apply_change_group can be ignored; see canon_reg.  */
     The result of apply_change_group can be ignored; see canon_reg.  */
 
 
  apply_change_group ();
  apply_change_group ();
 
 
  /* Set sets[i].src_elt to the class each source belongs to.
  /* Set sets[i].src_elt to the class each source belongs to.
     Detect assignments from or to volatile things
     Detect assignments from or to volatile things
     and set set[i] to zero so they will be ignored
     and set set[i] to zero so they will be ignored
     in the rest of this function.
     in the rest of this function.
 
 
     Nothing in this loop changes the hash table or the register chains.  */
     Nothing in this loop changes the hash table or the register chains.  */
 
 
  for (i = 0; i < n_sets; i++)
  for (i = 0; i < n_sets; i++)
    {
    {
      rtx src, dest;
      rtx src, dest;
      rtx src_folded;
      rtx src_folded;
      struct table_elt *elt = 0, *p;
      struct table_elt *elt = 0, *p;
      enum machine_mode mode;
      enum machine_mode mode;
      rtx src_eqv_here;
      rtx src_eqv_here;
      rtx src_const = 0;
      rtx src_const = 0;
      rtx src_related = 0;
      rtx src_related = 0;
      struct table_elt *src_const_elt = 0;
      struct table_elt *src_const_elt = 0;
      int src_cost = MAX_COST;
      int src_cost = MAX_COST;
      int src_eqv_cost = MAX_COST;
      int src_eqv_cost = MAX_COST;
      int src_folded_cost = MAX_COST;
      int src_folded_cost = MAX_COST;
      int src_related_cost = MAX_COST;
      int src_related_cost = MAX_COST;
      int src_elt_cost = MAX_COST;
      int src_elt_cost = MAX_COST;
      int src_regcost = MAX_COST;
      int src_regcost = MAX_COST;
      int src_eqv_regcost = MAX_COST;
      int src_eqv_regcost = MAX_COST;
      int src_folded_regcost = MAX_COST;
      int src_folded_regcost = MAX_COST;
      int src_related_regcost = MAX_COST;
      int src_related_regcost = MAX_COST;
      int src_elt_regcost = MAX_COST;
      int src_elt_regcost = MAX_COST;
      /* Set nonzero if we need to call force_const_mem on with the
      /* Set nonzero if we need to call force_const_mem on with the
         contents of src_folded before using it.  */
         contents of src_folded before using it.  */
      int src_folded_force_flag = 0;
      int src_folded_force_flag = 0;
 
 
      dest = SET_DEST (sets[i].rtl);
      dest = SET_DEST (sets[i].rtl);
      src = SET_SRC (sets[i].rtl);
      src = SET_SRC (sets[i].rtl);
 
 
      /* If SRC is a constant that has no machine mode,
      /* If SRC is a constant that has no machine mode,
         hash it with the destination's machine mode.
         hash it with the destination's machine mode.
         This way we can keep different modes separate.  */
         This way we can keep different modes separate.  */
 
 
      mode = GET_MODE (src) == VOIDmode ? GET_MODE (dest) : GET_MODE (src);
      mode = GET_MODE (src) == VOIDmode ? GET_MODE (dest) : GET_MODE (src);
      sets[i].mode = mode;
      sets[i].mode = mode;
 
 
      if (src_eqv)
      if (src_eqv)
        {
        {
          enum machine_mode eqvmode = mode;
          enum machine_mode eqvmode = mode;
          if (GET_CODE (dest) == STRICT_LOW_PART)
          if (GET_CODE (dest) == STRICT_LOW_PART)
            eqvmode = GET_MODE (SUBREG_REG (XEXP (dest, 0)));
            eqvmode = GET_MODE (SUBREG_REG (XEXP (dest, 0)));
          do_not_record = 0;
          do_not_record = 0;
          hash_arg_in_memory = 0;
          hash_arg_in_memory = 0;
          src_eqv_hash = HASH (src_eqv, eqvmode);
          src_eqv_hash = HASH (src_eqv, eqvmode);
 
 
          /* Find the equivalence class for the equivalent expression.  */
          /* Find the equivalence class for the equivalent expression.  */
 
 
          if (!do_not_record)
          if (!do_not_record)
            src_eqv_elt = lookup (src_eqv, src_eqv_hash, eqvmode);
            src_eqv_elt = lookup (src_eqv, src_eqv_hash, eqvmode);
 
 
          src_eqv_volatile = do_not_record;
          src_eqv_volatile = do_not_record;
          src_eqv_in_memory = hash_arg_in_memory;
          src_eqv_in_memory = hash_arg_in_memory;
        }
        }
 
 
      /* If this is a STRICT_LOW_PART assignment, src_eqv corresponds to the
      /* If this is a STRICT_LOW_PART assignment, src_eqv corresponds to the
         value of the INNER register, not the destination.  So it is not
         value of the INNER register, not the destination.  So it is not
         a valid substitution for the source.  But save it for later.  */
         a valid substitution for the source.  But save it for later.  */
      if (GET_CODE (dest) == STRICT_LOW_PART)
      if (GET_CODE (dest) == STRICT_LOW_PART)
        src_eqv_here = 0;
        src_eqv_here = 0;
      else
      else
        src_eqv_here = src_eqv;
        src_eqv_here = src_eqv;
 
 
      /* Simplify and foldable subexpressions in SRC.  Then get the fully-
      /* Simplify and foldable subexpressions in SRC.  Then get the fully-
         simplified result, which may not necessarily be valid.  */
         simplified result, which may not necessarily be valid.  */
      src_folded = fold_rtx (src, insn);
      src_folded = fold_rtx (src, insn);
 
 
#if 0
#if 0
      /* ??? This caused bad code to be generated for the m68k port with -O2.
      /* ??? This caused bad code to be generated for the m68k port with -O2.
         Suppose src is (CONST_INT -1), and that after truncation src_folded
         Suppose src is (CONST_INT -1), and that after truncation src_folded
         is (CONST_INT 3).  Suppose src_folded is then used for src_const.
         is (CONST_INT 3).  Suppose src_folded is then used for src_const.
         At the end we will add src and src_const to the same equivalence
         At the end we will add src and src_const to the same equivalence
         class.  We now have 3 and -1 on the same equivalence class.  This
         class.  We now have 3 and -1 on the same equivalence class.  This
         causes later instructions to be mis-optimized.  */
         causes later instructions to be mis-optimized.  */
      /* If storing a constant in a bitfield, pre-truncate the constant
      /* If storing a constant in a bitfield, pre-truncate the constant
         so we will be able to record it later.  */
         so we will be able to record it later.  */
      if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT)
      if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT)
        {
        {
          rtx width = XEXP (SET_DEST (sets[i].rtl), 1);
          rtx width = XEXP (SET_DEST (sets[i].rtl), 1);
 
 
          if (GET_CODE (src) == CONST_INT
          if (GET_CODE (src) == CONST_INT
              && GET_CODE (width) == CONST_INT
              && GET_CODE (width) == CONST_INT
              && INTVAL (width) < HOST_BITS_PER_WIDE_INT
              && INTVAL (width) < HOST_BITS_PER_WIDE_INT
              && (INTVAL (src) & ((HOST_WIDE_INT) (-1) << INTVAL (width))))
              && (INTVAL (src) & ((HOST_WIDE_INT) (-1) << INTVAL (width))))
            src_folded
            src_folded
              = GEN_INT (INTVAL (src) & (((HOST_WIDE_INT) 1
              = GEN_INT (INTVAL (src) & (((HOST_WIDE_INT) 1
                                          << INTVAL (width)) - 1));
                                          << INTVAL (width)) - 1));
        }
        }
#endif
#endif
 
 
      /* Compute SRC's hash code, and also notice if it
      /* Compute SRC's hash code, and also notice if it
         should not be recorded at all.  In that case,
         should not be recorded at all.  In that case,
         prevent any further processing of this assignment.  */
         prevent any further processing of this assignment.  */
      do_not_record = 0;
      do_not_record = 0;
      hash_arg_in_memory = 0;
      hash_arg_in_memory = 0;
 
 
      sets[i].src = src;
      sets[i].src = src;
      sets[i].src_hash = HASH (src, mode);
      sets[i].src_hash = HASH (src, mode);
      sets[i].src_volatile = do_not_record;
      sets[i].src_volatile = do_not_record;
      sets[i].src_in_memory = hash_arg_in_memory;
      sets[i].src_in_memory = hash_arg_in_memory;
 
 
      /* If SRC is a MEM, there is a REG_EQUIV note for SRC, and DEST is
      /* If SRC is a MEM, there is a REG_EQUIV note for SRC, and DEST is
         a pseudo, do not record SRC.  Using SRC as a replacement for
         a pseudo, do not record SRC.  Using SRC as a replacement for
         anything else will be incorrect in that situation.  Note that
         anything else will be incorrect in that situation.  Note that
         this usually occurs only for stack slots, in which case all the
         this usually occurs only for stack slots, in which case all the
         RTL would be referring to SRC, so we don't lose any optimization
         RTL would be referring to SRC, so we don't lose any optimization
         opportunities by not having SRC in the hash table.  */
         opportunities by not having SRC in the hash table.  */
 
 
      if (MEM_P (src)
      if (MEM_P (src)
          && find_reg_note (insn, REG_EQUIV, NULL_RTX) != 0
          && find_reg_note (insn, REG_EQUIV, NULL_RTX) != 0
          && REG_P (dest)
          && REG_P (dest)
          && REGNO (dest) >= FIRST_PSEUDO_REGISTER)
          && REGNO (dest) >= FIRST_PSEUDO_REGISTER)
        sets[i].src_volatile = 1;
        sets[i].src_volatile = 1;
 
 
#if 0
#if 0
      /* It is no longer clear why we used to do this, but it doesn't
      /* It is no longer clear why we used to do this, but it doesn't
         appear to still be needed.  So let's try without it since this
         appear to still be needed.  So let's try without it since this
         code hurts cse'ing widened ops.  */
         code hurts cse'ing widened ops.  */
      /* If source is a paradoxical subreg (such as QI treated as an SI),
      /* If source is a paradoxical subreg (such as QI treated as an SI),
         treat it as volatile.  It may do the work of an SI in one context
         treat it as volatile.  It may do the work of an SI in one context
         where the extra bits are not being used, but cannot replace an SI
         where the extra bits are not being used, but cannot replace an SI
         in general.  */
         in general.  */
      if (GET_CODE (src) == SUBREG
      if (GET_CODE (src) == SUBREG
          && (GET_MODE_SIZE (GET_MODE (src))
          && (GET_MODE_SIZE (GET_MODE (src))
              > GET_MODE_SIZE (GET_MODE (SUBREG_REG (src)))))
              > GET_MODE_SIZE (GET_MODE (SUBREG_REG (src)))))
        sets[i].src_volatile = 1;
        sets[i].src_volatile = 1;
#endif
#endif
 
 
      /* Locate all possible equivalent forms for SRC.  Try to replace
      /* Locate all possible equivalent forms for SRC.  Try to replace
         SRC in the insn with each cheaper equivalent.
         SRC in the insn with each cheaper equivalent.
 
 
         We have the following types of equivalents: SRC itself, a folded
         We have the following types of equivalents: SRC itself, a folded
         version, a value given in a REG_EQUAL note, or a value related
         version, a value given in a REG_EQUAL note, or a value related
         to a constant.
         to a constant.
 
 
         Each of these equivalents may be part of an additional class
         Each of these equivalents may be part of an additional class
         of equivalents (if more than one is in the table, they must be in
         of equivalents (if more than one is in the table, they must be in
         the same class; we check for this).
         the same class; we check for this).
 
 
         If the source is volatile, we don't do any table lookups.
         If the source is volatile, we don't do any table lookups.
 
 
         We note any constant equivalent for possible later use in a
         We note any constant equivalent for possible later use in a
         REG_NOTE.  */
         REG_NOTE.  */
 
 
      if (!sets[i].src_volatile)
      if (!sets[i].src_volatile)
        elt = lookup (src, sets[i].src_hash, mode);
        elt = lookup (src, sets[i].src_hash, mode);
 
 
      sets[i].src_elt = elt;
      sets[i].src_elt = elt;
 
 
      if (elt && src_eqv_here && src_eqv_elt)
      if (elt && src_eqv_here && src_eqv_elt)
        {
        {
          if (elt->first_same_value != src_eqv_elt->first_same_value)
          if (elt->first_same_value != src_eqv_elt->first_same_value)
            {
            {
              /* The REG_EQUAL is indicating that two formerly distinct
              /* The REG_EQUAL is indicating that two formerly distinct
                 classes are now equivalent.  So merge them.  */
                 classes are now equivalent.  So merge them.  */
              merge_equiv_classes (elt, src_eqv_elt);
              merge_equiv_classes (elt, src_eqv_elt);
              src_eqv_hash = HASH (src_eqv, elt->mode);
              src_eqv_hash = HASH (src_eqv, elt->mode);
              src_eqv_elt = lookup (src_eqv, src_eqv_hash, elt->mode);
              src_eqv_elt = lookup (src_eqv, src_eqv_hash, elt->mode);
            }
            }
 
 
          src_eqv_here = 0;
          src_eqv_here = 0;
        }
        }
 
 
      else if (src_eqv_elt)
      else if (src_eqv_elt)
        elt = src_eqv_elt;
        elt = src_eqv_elt;
 
 
      /* Try to find a constant somewhere and record it in `src_const'.
      /* Try to find a constant somewhere and record it in `src_const'.
         Record its table element, if any, in `src_const_elt'.  Look in
         Record its table element, if any, in `src_const_elt'.  Look in
         any known equivalences first.  (If the constant is not in the
         any known equivalences first.  (If the constant is not in the
         table, also set `sets[i].src_const_hash').  */
         table, also set `sets[i].src_const_hash').  */
      if (elt)
      if (elt)
        for (p = elt->first_same_value; p; p = p->next_same_value)
        for (p = elt->first_same_value; p; p = p->next_same_value)
          if (p->is_const)
          if (p->is_const)
            {
            {
              src_const = p->exp;
              src_const = p->exp;
              src_const_elt = elt;
              src_const_elt = elt;
              break;
              break;
            }
            }
 
 
      if (src_const == 0
      if (src_const == 0
          && (CONSTANT_P (src_folded)
          && (CONSTANT_P (src_folded)
              /* Consider (minus (label_ref L1) (label_ref L2)) as
              /* Consider (minus (label_ref L1) (label_ref L2)) as
                 "constant" here so we will record it. This allows us
                 "constant" here so we will record it. This allows us
                 to fold switch statements when an ADDR_DIFF_VEC is used.  */
                 to fold switch statements when an ADDR_DIFF_VEC is used.  */
              || (GET_CODE (src_folded) == MINUS
              || (GET_CODE (src_folded) == MINUS
                  && GET_CODE (XEXP (src_folded, 0)) == LABEL_REF
                  && GET_CODE (XEXP (src_folded, 0)) == LABEL_REF
                  && GET_CODE (XEXP (src_folded, 1)) == LABEL_REF)))
                  && GET_CODE (XEXP (src_folded, 1)) == LABEL_REF)))
        src_const = src_folded, src_const_elt = elt;
        src_const = src_folded, src_const_elt = elt;
      else if (src_const == 0 && src_eqv_here && CONSTANT_P (src_eqv_here))
      else if (src_const == 0 && src_eqv_here && CONSTANT_P (src_eqv_here))
        src_const = src_eqv_here, src_const_elt = src_eqv_elt;
        src_const = src_eqv_here, src_const_elt = src_eqv_elt;
 
 
      /* If we don't know if the constant is in the table, get its
      /* If we don't know if the constant is in the table, get its
         hash code and look it up.  */
         hash code and look it up.  */
      if (src_const && src_const_elt == 0)
      if (src_const && src_const_elt == 0)
        {
        {
          sets[i].src_const_hash = HASH (src_const, mode);
          sets[i].src_const_hash = HASH (src_const, mode);
          src_const_elt = lookup (src_const, sets[i].src_const_hash, mode);
          src_const_elt = lookup (src_const, sets[i].src_const_hash, mode);
        }
        }
 
 
      sets[i].src_const = src_const;
      sets[i].src_const = src_const;
      sets[i].src_const_elt = src_const_elt;
      sets[i].src_const_elt = src_const_elt;
 
 
      /* If the constant and our source are both in the table, mark them as
      /* If the constant and our source are both in the table, mark them as
         equivalent.  Otherwise, if a constant is in the table but the source
         equivalent.  Otherwise, if a constant is in the table but the source
         isn't, set ELT to it.  */
         isn't, set ELT to it.  */
      if (src_const_elt && elt
      if (src_const_elt && elt
          && src_const_elt->first_same_value != elt->first_same_value)
          && src_const_elt->first_same_value != elt->first_same_value)
        merge_equiv_classes (elt, src_const_elt);
        merge_equiv_classes (elt, src_const_elt);
      else if (src_const_elt && elt == 0)
      else if (src_const_elt && elt == 0)
        elt = src_const_elt;
        elt = src_const_elt;
 
 
      /* See if there is a register linearly related to a constant
      /* See if there is a register linearly related to a constant
         equivalent of SRC.  */
         equivalent of SRC.  */
      if (src_const
      if (src_const
          && (GET_CODE (src_const) == CONST
          && (GET_CODE (src_const) == CONST
              || (src_const_elt && src_const_elt->related_value != 0)))
              || (src_const_elt && src_const_elt->related_value != 0)))
        {
        {
          src_related = use_related_value (src_const, src_const_elt);
          src_related = use_related_value (src_const, src_const_elt);
          if (src_related)
          if (src_related)
            {
            {
              struct table_elt *src_related_elt
              struct table_elt *src_related_elt
                = lookup (src_related, HASH (src_related, mode), mode);
                = lookup (src_related, HASH (src_related, mode), mode);
              if (src_related_elt && elt)
              if (src_related_elt && elt)
                {
                {
                  if (elt->first_same_value
                  if (elt->first_same_value
                      != src_related_elt->first_same_value)
                      != src_related_elt->first_same_value)
                    /* This can occur when we previously saw a CONST
                    /* This can occur when we previously saw a CONST
                       involving a SYMBOL_REF and then see the SYMBOL_REF
                       involving a SYMBOL_REF and then see the SYMBOL_REF
                       twice.  Merge the involved classes.  */
                       twice.  Merge the involved classes.  */
                    merge_equiv_classes (elt, src_related_elt);
                    merge_equiv_classes (elt, src_related_elt);
 
 
                  src_related = 0;
                  src_related = 0;
                  src_related_elt = 0;
                  src_related_elt = 0;
                }
                }
              else if (src_related_elt && elt == 0)
              else if (src_related_elt && elt == 0)
                elt = src_related_elt;
                elt = src_related_elt;
            }
            }
        }
        }
 
 
      /* See if we have a CONST_INT that is already in a register in a
      /* See if we have a CONST_INT that is already in a register in a
         wider mode.  */
         wider mode.  */
 
 
      if (src_const && src_related == 0 && GET_CODE (src_const) == CONST_INT
      if (src_const && src_related == 0 && GET_CODE (src_const) == CONST_INT
          && GET_MODE_CLASS (mode) == MODE_INT
          && GET_MODE_CLASS (mode) == MODE_INT
          && GET_MODE_BITSIZE (mode) < BITS_PER_WORD)
          && GET_MODE_BITSIZE (mode) < BITS_PER_WORD)
        {
        {
          enum machine_mode wider_mode;
          enum machine_mode wider_mode;
 
 
          for (wider_mode = GET_MODE_WIDER_MODE (mode);
          for (wider_mode = GET_MODE_WIDER_MODE (mode);
               GET_MODE_BITSIZE (wider_mode) <= BITS_PER_WORD
               GET_MODE_BITSIZE (wider_mode) <= BITS_PER_WORD
               && src_related == 0;
               && src_related == 0;
               wider_mode = GET_MODE_WIDER_MODE (wider_mode))
               wider_mode = GET_MODE_WIDER_MODE (wider_mode))
            {
            {
              struct table_elt *const_elt
              struct table_elt *const_elt
                = lookup (src_const, HASH (src_const, wider_mode), wider_mode);
                = lookup (src_const, HASH (src_const, wider_mode), wider_mode);
 
 
              if (const_elt == 0)
              if (const_elt == 0)
                continue;
                continue;
 
 
              for (const_elt = const_elt->first_same_value;
              for (const_elt = const_elt->first_same_value;
                   const_elt; const_elt = const_elt->next_same_value)
                   const_elt; const_elt = const_elt->next_same_value)
                if (REG_P (const_elt->exp))
                if (REG_P (const_elt->exp))
                  {
                  {
                    src_related = gen_lowpart (mode,
                    src_related = gen_lowpart (mode,
                                                           const_elt->exp);
                                                           const_elt->exp);
                    break;
                    break;
                  }
                  }
            }
            }
        }
        }
 
 
      /* Another possibility is that we have an AND with a constant in
      /* Another possibility is that we have an AND with a constant in
         a mode narrower than a word.  If so, it might have been generated
         a mode narrower than a word.  If so, it might have been generated
         as part of an "if" which would narrow the AND.  If we already
         as part of an "if" which would narrow the AND.  If we already
         have done the AND in a wider mode, we can use a SUBREG of that
         have done the AND in a wider mode, we can use a SUBREG of that
         value.  */
         value.  */
 
 
      if (flag_expensive_optimizations && ! src_related
      if (flag_expensive_optimizations && ! src_related
          && GET_CODE (src) == AND && GET_CODE (XEXP (src, 1)) == CONST_INT
          && GET_CODE (src) == AND && GET_CODE (XEXP (src, 1)) == CONST_INT
          && GET_MODE_SIZE (mode) < UNITS_PER_WORD)
          && GET_MODE_SIZE (mode) < UNITS_PER_WORD)
        {
        {
          enum machine_mode tmode;
          enum machine_mode tmode;
          rtx new_and = gen_rtx_AND (VOIDmode, NULL_RTX, XEXP (src, 1));
          rtx new_and = gen_rtx_AND (VOIDmode, NULL_RTX, XEXP (src, 1));
 
 
          for (tmode = GET_MODE_WIDER_MODE (mode);
          for (tmode = GET_MODE_WIDER_MODE (mode);
               GET_MODE_SIZE (tmode) <= UNITS_PER_WORD;
               GET_MODE_SIZE (tmode) <= UNITS_PER_WORD;
               tmode = GET_MODE_WIDER_MODE (tmode))
               tmode = GET_MODE_WIDER_MODE (tmode))
            {
            {
              rtx inner = gen_lowpart (tmode, XEXP (src, 0));
              rtx inner = gen_lowpart (tmode, XEXP (src, 0));
              struct table_elt *larger_elt;
              struct table_elt *larger_elt;
 
 
              if (inner)
              if (inner)
                {
                {
                  PUT_MODE (new_and, tmode);
                  PUT_MODE (new_and, tmode);
                  XEXP (new_and, 0) = inner;
                  XEXP (new_and, 0) = inner;
                  larger_elt = lookup (new_and, HASH (new_and, tmode), tmode);
                  larger_elt = lookup (new_and, HASH (new_and, tmode), tmode);
                  if (larger_elt == 0)
                  if (larger_elt == 0)
                    continue;
                    continue;
 
 
                  for (larger_elt = larger_elt->first_same_value;
                  for (larger_elt = larger_elt->first_same_value;
                       larger_elt; larger_elt = larger_elt->next_same_value)
                       larger_elt; larger_elt = larger_elt->next_same_value)
                    if (REG_P (larger_elt->exp))
                    if (REG_P (larger_elt->exp))
                      {
                      {
                        src_related
                        src_related
                          = gen_lowpart (mode, larger_elt->exp);
                          = gen_lowpart (mode, larger_elt->exp);
                        break;
                        break;
                      }
                      }
 
 
                  if (src_related)
                  if (src_related)
                    break;
                    break;
                }
                }
            }
            }
        }
        }
 
 
#ifdef LOAD_EXTEND_OP
#ifdef LOAD_EXTEND_OP
      /* See if a MEM has already been loaded with a widening operation;
      /* See if a MEM has already been loaded with a widening operation;
         if it has, we can use a subreg of that.  Many CISC machines
         if it has, we can use a subreg of that.  Many CISC machines
         also have such operations, but this is only likely to be
         also have such operations, but this is only likely to be
         beneficial on these machines.  */
         beneficial on these machines.  */
 
 
      if (flag_expensive_optimizations && src_related == 0
      if (flag_expensive_optimizations && src_related == 0
          && (GET_MODE_SIZE (mode) < UNITS_PER_WORD)
          && (GET_MODE_SIZE (mode) < UNITS_PER_WORD)
          && GET_MODE_CLASS (mode) == MODE_INT
          && GET_MODE_CLASS (mode) == MODE_INT
          && MEM_P (src) && ! do_not_record
          && MEM_P (src) && ! do_not_record
          && LOAD_EXTEND_OP (mode) != UNKNOWN)
          && LOAD_EXTEND_OP (mode) != UNKNOWN)
        {
        {
          struct rtx_def memory_extend_buf;
          struct rtx_def memory_extend_buf;
          rtx memory_extend_rtx = &memory_extend_buf;
          rtx memory_extend_rtx = &memory_extend_buf;
          enum machine_mode tmode;
          enum machine_mode tmode;
 
 
          /* Set what we are trying to extend and the operation it might
          /* Set what we are trying to extend and the operation it might
             have been extended with.  */
             have been extended with.  */
          memset (memory_extend_rtx, 0, sizeof(*memory_extend_rtx));
          memset (memory_extend_rtx, 0, sizeof(*memory_extend_rtx));
          PUT_CODE (memory_extend_rtx, LOAD_EXTEND_OP (mode));
          PUT_CODE (memory_extend_rtx, LOAD_EXTEND_OP (mode));
          XEXP (memory_extend_rtx, 0) = src;
          XEXP (memory_extend_rtx, 0) = src;
 
 
          for (tmode = GET_MODE_WIDER_MODE (mode);
          for (tmode = GET_MODE_WIDER_MODE (mode);
               GET_MODE_SIZE (tmode) <= UNITS_PER_WORD;
               GET_MODE_SIZE (tmode) <= UNITS_PER_WORD;
               tmode = GET_MODE_WIDER_MODE (tmode))
               tmode = GET_MODE_WIDER_MODE (tmode))
            {
            {
              struct table_elt *larger_elt;
              struct table_elt *larger_elt;
 
 
              PUT_MODE (memory_extend_rtx, tmode);
              PUT_MODE (memory_extend_rtx, tmode);
              larger_elt = lookup (memory_extend_rtx,
              larger_elt = lookup (memory_extend_rtx,
                                   HASH (memory_extend_rtx, tmode), tmode);
                                   HASH (memory_extend_rtx, tmode), tmode);
              if (larger_elt == 0)
              if (larger_elt == 0)
                continue;
                continue;
 
 
              for (larger_elt = larger_elt->first_same_value;
              for (larger_elt = larger_elt->first_same_value;
                   larger_elt; larger_elt = larger_elt->next_same_value)
                   larger_elt; larger_elt = larger_elt->next_same_value)
                if (REG_P (larger_elt->exp))
                if (REG_P (larger_elt->exp))
                  {
                  {
                    src_related = gen_lowpart (mode,
                    src_related = gen_lowpart (mode,
                                                           larger_elt->exp);
                                                           larger_elt->exp);
                    break;
                    break;
                  }
                  }
 
 
              if (src_related)
              if (src_related)
                break;
                break;
            }
            }
        }
        }
#endif /* LOAD_EXTEND_OP */
#endif /* LOAD_EXTEND_OP */
 
 
      if (src == src_folded)
      if (src == src_folded)
        src_folded = 0;
        src_folded = 0;
 
 
      /* At this point, ELT, if nonzero, points to a class of expressions
      /* At this point, ELT, if nonzero, points to a class of expressions
         equivalent to the source of this SET and SRC, SRC_EQV, SRC_FOLDED,
         equivalent to the source of this SET and SRC, SRC_EQV, SRC_FOLDED,
         and SRC_RELATED, if nonzero, each contain additional equivalent
         and SRC_RELATED, if nonzero, each contain additional equivalent
         expressions.  Prune these latter expressions by deleting expressions
         expressions.  Prune these latter expressions by deleting expressions
         already in the equivalence class.
         already in the equivalence class.
 
 
         Check for an equivalent identical to the destination.  If found,
         Check for an equivalent identical to the destination.  If found,
         this is the preferred equivalent since it will likely lead to
         this is the preferred equivalent since it will likely lead to
         elimination of the insn.  Indicate this by placing it in
         elimination of the insn.  Indicate this by placing it in
         `src_related'.  */
         `src_related'.  */
 
 
      if (elt)
      if (elt)
        elt = elt->first_same_value;
        elt = elt->first_same_value;
      for (p = elt; p; p = p->next_same_value)
      for (p = elt; p; p = p->next_same_value)
        {
        {
          enum rtx_code code = GET_CODE (p->exp);
          enum rtx_code code = GET_CODE (p->exp);
 
 
          /* If the expression is not valid, ignore it.  Then we do not
          /* If the expression is not valid, ignore it.  Then we do not
             have to check for validity below.  In most cases, we can use
             have to check for validity below.  In most cases, we can use
             `rtx_equal_p', since canonicalization has already been done.  */
             `rtx_equal_p', since canonicalization has already been done.  */
          if (code != REG && ! exp_equiv_p (p->exp, p->exp, 1, false))
          if (code != REG && ! exp_equiv_p (p->exp, p->exp, 1, false))
            continue;
            continue;
 
 
          /* Also skip paradoxical subregs, unless that's what we're
          /* Also skip paradoxical subregs, unless that's what we're
             looking for.  */
             looking for.  */
          if (code == SUBREG
          if (code == SUBREG
              && (GET_MODE_SIZE (GET_MODE (p->exp))
              && (GET_MODE_SIZE (GET_MODE (p->exp))
                  > GET_MODE_SIZE (GET_MODE (SUBREG_REG (p->exp))))
                  > GET_MODE_SIZE (GET_MODE (SUBREG_REG (p->exp))))
              && ! (src != 0
              && ! (src != 0
                    && GET_CODE (src) == SUBREG
                    && GET_CODE (src) == SUBREG
                    && GET_MODE (src) == GET_MODE (p->exp)
                    && GET_MODE (src) == GET_MODE (p->exp)
                    && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (src)))
                    && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (src)))
                        < GET_MODE_SIZE (GET_MODE (SUBREG_REG (p->exp))))))
                        < GET_MODE_SIZE (GET_MODE (SUBREG_REG (p->exp))))))
            continue;
            continue;
 
 
          if (src && GET_CODE (src) == code && rtx_equal_p (src, p->exp))
          if (src && GET_CODE (src) == code && rtx_equal_p (src, p->exp))
            src = 0;
            src = 0;
          else if (src_folded && GET_CODE (src_folded) == code
          else if (src_folded && GET_CODE (src_folded) == code
                   && rtx_equal_p (src_folded, p->exp))
                   && rtx_equal_p (src_folded, p->exp))
            src_folded = 0;
            src_folded = 0;
          else if (src_eqv_here && GET_CODE (src_eqv_here) == code
          else if (src_eqv_here && GET_CODE (src_eqv_here) == code
                   && rtx_equal_p (src_eqv_here, p->exp))
                   && rtx_equal_p (src_eqv_here, p->exp))
            src_eqv_here = 0;
            src_eqv_here = 0;
          else if (src_related && GET_CODE (src_related) == code
          else if (src_related && GET_CODE (src_related) == code
                   && rtx_equal_p (src_related, p->exp))
                   && rtx_equal_p (src_related, p->exp))
            src_related = 0;
            src_related = 0;
 
 
          /* This is the same as the destination of the insns, we want
          /* This is the same as the destination of the insns, we want
             to prefer it.  Copy it to src_related.  The code below will
             to prefer it.  Copy it to src_related.  The code below will
             then give it a negative cost.  */
             then give it a negative cost.  */
          if (GET_CODE (dest) == code && rtx_equal_p (p->exp, dest))
          if (GET_CODE (dest) == code && rtx_equal_p (p->exp, dest))
            src_related = dest;
            src_related = dest;
        }
        }
 
 
      /* Find the cheapest valid equivalent, trying all the available
      /* Find the cheapest valid equivalent, trying all the available
         possibilities.  Prefer items not in the hash table to ones
         possibilities.  Prefer items not in the hash table to ones
         that are when they are equal cost.  Note that we can never
         that are when they are equal cost.  Note that we can never
         worsen an insn as the current contents will also succeed.
         worsen an insn as the current contents will also succeed.
         If we find an equivalent identical to the destination, use it as best,
         If we find an equivalent identical to the destination, use it as best,
         since this insn will probably be eliminated in that case.  */
         since this insn will probably be eliminated in that case.  */
      if (src)
      if (src)
        {
        {
          if (rtx_equal_p (src, dest))
          if (rtx_equal_p (src, dest))
            src_cost = src_regcost = -1;
            src_cost = src_regcost = -1;
          else
          else
            {
            {
              src_cost = COST (src);
              src_cost = COST (src);
              src_regcost = approx_reg_cost (src);
              src_regcost = approx_reg_cost (src);
            }
            }
        }
        }
 
 
      if (src_eqv_here)
      if (src_eqv_here)
        {
        {
          if (rtx_equal_p (src_eqv_here, dest))
          if (rtx_equal_p (src_eqv_here, dest))
            src_eqv_cost = src_eqv_regcost = -1;
            src_eqv_cost = src_eqv_regcost = -1;
          else
          else
            {
            {
              src_eqv_cost = COST (src_eqv_here);
              src_eqv_cost = COST (src_eqv_here);
              src_eqv_regcost = approx_reg_cost (src_eqv_here);
              src_eqv_regcost = approx_reg_cost (src_eqv_here);
            }
            }
        }
        }
 
 
      if (src_folded)
      if (src_folded)
        {
        {
          if (rtx_equal_p (src_folded, dest))
          if (rtx_equal_p (src_folded, dest))
            src_folded_cost = src_folded_regcost = -1;
            src_folded_cost = src_folded_regcost = -1;
          else
          else
            {
            {
              src_folded_cost = COST (src_folded);
              src_folded_cost = COST (src_folded);
              src_folded_regcost = approx_reg_cost (src_folded);
              src_folded_regcost = approx_reg_cost (src_folded);
            }
            }
        }
        }
 
 
      if (src_related)
      if (src_related)
        {
        {
          if (rtx_equal_p (src_related, dest))
          if (rtx_equal_p (src_related, dest))
            src_related_cost = src_related_regcost = -1;
            src_related_cost = src_related_regcost = -1;
          else
          else
            {
            {
              src_related_cost = COST (src_related);
              src_related_cost = COST (src_related);
              src_related_regcost = approx_reg_cost (src_related);
              src_related_regcost = approx_reg_cost (src_related);
            }
            }
        }
        }
 
 
      /* If this was an indirect jump insn, a known label will really be
      /* If this was an indirect jump insn, a known label will really be
         cheaper even though it looks more expensive.  */
         cheaper even though it looks more expensive.  */
      if (dest == pc_rtx && src_const && GET_CODE (src_const) == LABEL_REF)
      if (dest == pc_rtx && src_const && GET_CODE (src_const) == LABEL_REF)
        src_folded = src_const, src_folded_cost = src_folded_regcost = -1;
        src_folded = src_const, src_folded_cost = src_folded_regcost = -1;
 
 
      /* Terminate loop when replacement made.  This must terminate since
      /* Terminate loop when replacement made.  This must terminate since
         the current contents will be tested and will always be valid.  */
         the current contents will be tested and will always be valid.  */
      while (1)
      while (1)
        {
        {
          rtx trial;
          rtx trial;
 
 
          /* Skip invalid entries.  */
          /* Skip invalid entries.  */
          while (elt && !REG_P (elt->exp)
          while (elt && !REG_P (elt->exp)
                 && ! exp_equiv_p (elt->exp, elt->exp, 1, false))
                 && ! exp_equiv_p (elt->exp, elt->exp, 1, false))
            elt = elt->next_same_value;
            elt = elt->next_same_value;
 
 
          /* A paradoxical subreg would be bad here: it'll be the right
          /* A paradoxical subreg would be bad here: it'll be the right
             size, but later may be adjusted so that the upper bits aren't
             size, but later may be adjusted so that the upper bits aren't
             what we want.  So reject it.  */
             what we want.  So reject it.  */
          if (elt != 0
          if (elt != 0
              && GET_CODE (elt->exp) == SUBREG
              && GET_CODE (elt->exp) == SUBREG
              && (GET_MODE_SIZE (GET_MODE (elt->exp))
              && (GET_MODE_SIZE (GET_MODE (elt->exp))
                  > GET_MODE_SIZE (GET_MODE (SUBREG_REG (elt->exp))))
                  > GET_MODE_SIZE (GET_MODE (SUBREG_REG (elt->exp))))
              /* It is okay, though, if the rtx we're trying to match
              /* It is okay, though, if the rtx we're trying to match
                 will ignore any of the bits we can't predict.  */
                 will ignore any of the bits we can't predict.  */
              && ! (src != 0
              && ! (src != 0
                    && GET_CODE (src) == SUBREG
                    && GET_CODE (src) == SUBREG
                    && GET_MODE (src) == GET_MODE (elt->exp)
                    && GET_MODE (src) == GET_MODE (elt->exp)
                    && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (src)))
                    && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (src)))
                        < GET_MODE_SIZE (GET_MODE (SUBREG_REG (elt->exp))))))
                        < GET_MODE_SIZE (GET_MODE (SUBREG_REG (elt->exp))))))
            {
            {
              elt = elt->next_same_value;
              elt = elt->next_same_value;
              continue;
              continue;
            }
            }
 
 
          if (elt)
          if (elt)
            {
            {
              src_elt_cost = elt->cost;
              src_elt_cost = elt->cost;
              src_elt_regcost = elt->regcost;
              src_elt_regcost = elt->regcost;
            }
            }
 
 
          /* Find cheapest and skip it for the next time.   For items
          /* Find cheapest and skip it for the next time.   For items
             of equal cost, use this order:
             of equal cost, use this order:
             src_folded, src, src_eqv, src_related and hash table entry.  */
             src_folded, src, src_eqv, src_related and hash table entry.  */
          if (src_folded
          if (src_folded
              && preferable (src_folded_cost, src_folded_regcost,
              && preferable (src_folded_cost, src_folded_regcost,
                             src_cost, src_regcost) <= 0
                             src_cost, src_regcost) <= 0
              && preferable (src_folded_cost, src_folded_regcost,
              && preferable (src_folded_cost, src_folded_regcost,
                             src_eqv_cost, src_eqv_regcost) <= 0
                             src_eqv_cost, src_eqv_regcost) <= 0
              && preferable (src_folded_cost, src_folded_regcost,
              && preferable (src_folded_cost, src_folded_regcost,
                             src_related_cost, src_related_regcost) <= 0
                             src_related_cost, src_related_regcost) <= 0
              && preferable (src_folded_cost, src_folded_regcost,
              && preferable (src_folded_cost, src_folded_regcost,
                             src_elt_cost, src_elt_regcost) <= 0)
                             src_elt_cost, src_elt_regcost) <= 0)
            {
            {
              trial = src_folded, src_folded_cost = MAX_COST;
              trial = src_folded, src_folded_cost = MAX_COST;
              if (src_folded_force_flag)
              if (src_folded_force_flag)
                {
                {
                  rtx forced = force_const_mem (mode, trial);
                  rtx forced = force_const_mem (mode, trial);
                  if (forced)
                  if (forced)
                    trial = forced;
                    trial = forced;
                }
                }
            }
            }
          else if (src
          else if (src
                   && preferable (src_cost, src_regcost,
                   && preferable (src_cost, src_regcost,
                                  src_eqv_cost, src_eqv_regcost) <= 0
                                  src_eqv_cost, src_eqv_regcost) <= 0
                   && preferable (src_cost, src_regcost,
                   && preferable (src_cost, src_regcost,
                                  src_related_cost, src_related_regcost) <= 0
                                  src_related_cost, src_related_regcost) <= 0
                   && preferable (src_cost, src_regcost,
                   && preferable (src_cost, src_regcost,
                                  src_elt_cost, src_elt_regcost) <= 0)
                                  src_elt_cost, src_elt_regcost) <= 0)
            trial = src, src_cost = MAX_COST;
            trial = src, src_cost = MAX_COST;
          else if (src_eqv_here
          else if (src_eqv_here
                   && preferable (src_eqv_cost, src_eqv_regcost,
                   && preferable (src_eqv_cost, src_eqv_regcost,
                                  src_related_cost, src_related_regcost) <= 0
                                  src_related_cost, src_related_regcost) <= 0
                   && preferable (src_eqv_cost, src_eqv_regcost,
                   && preferable (src_eqv_cost, src_eqv_regcost,
                                  src_elt_cost, src_elt_regcost) <= 0)
                                  src_elt_cost, src_elt_regcost) <= 0)
            trial = copy_rtx (src_eqv_here), src_eqv_cost = MAX_COST;
            trial = copy_rtx (src_eqv_here), src_eqv_cost = MAX_COST;
          else if (src_related
          else if (src_related
                   && preferable (src_related_cost, src_related_regcost,
                   && preferable (src_related_cost, src_related_regcost,
                                  src_elt_cost, src_elt_regcost) <= 0)
                                  src_elt_cost, src_elt_regcost) <= 0)
            trial = copy_rtx (src_related), src_related_cost = MAX_COST;
            trial = copy_rtx (src_related), src_related_cost = MAX_COST;
          else
          else
            {
            {
              trial = copy_rtx (elt->exp);
              trial = copy_rtx (elt->exp);
              elt = elt->next_same_value;
              elt = elt->next_same_value;
              src_elt_cost = MAX_COST;
              src_elt_cost = MAX_COST;
            }
            }
 
 
          /* We don't normally have an insn matching (set (pc) (pc)), so
          /* We don't normally have an insn matching (set (pc) (pc)), so
             check for this separately here.  We will delete such an
             check for this separately here.  We will delete such an
             insn below.
             insn below.
 
 
             For other cases such as a table jump or conditional jump
             For other cases such as a table jump or conditional jump
             where we know the ultimate target, go ahead and replace the
             where we know the ultimate target, go ahead and replace the
             operand.  While that may not make a valid insn, we will
             operand.  While that may not make a valid insn, we will
             reemit the jump below (and also insert any necessary
             reemit the jump below (and also insert any necessary
             barriers).  */
             barriers).  */
          if (n_sets == 1 && dest == pc_rtx
          if (n_sets == 1 && dest == pc_rtx
              && (trial == pc_rtx
              && (trial == pc_rtx
                  || (GET_CODE (trial) == LABEL_REF
                  || (GET_CODE (trial) == LABEL_REF
                      && ! condjump_p (insn))))
                      && ! condjump_p (insn))))
            {
            {
              /* Don't substitute non-local labels, this confuses CFG.  */
              /* Don't substitute non-local labels, this confuses CFG.  */
              if (GET_CODE (trial) == LABEL_REF
              if (GET_CODE (trial) == LABEL_REF
                  && LABEL_REF_NONLOCAL_P (trial))
                  && LABEL_REF_NONLOCAL_P (trial))
                continue;
                continue;
 
 
              SET_SRC (sets[i].rtl) = trial;
              SET_SRC (sets[i].rtl) = trial;
              cse_jumps_altered = 1;
              cse_jumps_altered = 1;
              break;
              break;
            }
            }
 
 
          /* Reject certain invalid forms of CONST that we create.  */
          /* Reject certain invalid forms of CONST that we create.  */
          else if (CONSTANT_P (trial)
          else if (CONSTANT_P (trial)
                   && GET_CODE (trial) == CONST
                   && GET_CODE (trial) == CONST
                   /* Reject cases that will cause decode_rtx_const to
                   /* Reject cases that will cause decode_rtx_const to
                      die.  On the alpha when simplifying a switch, we
                      die.  On the alpha when simplifying a switch, we
                      get (const (truncate (minus (label_ref)
                      get (const (truncate (minus (label_ref)
                      (label_ref)))).  */
                      (label_ref)))).  */
                   && (GET_CODE (XEXP (trial, 0)) == TRUNCATE
                   && (GET_CODE (XEXP (trial, 0)) == TRUNCATE
                       /* Likewise on IA-64, except without the
                       /* Likewise on IA-64, except without the
                          truncate.  */
                          truncate.  */
                       || (GET_CODE (XEXP (trial, 0)) == MINUS
                       || (GET_CODE (XEXP (trial, 0)) == MINUS
                           && GET_CODE (XEXP (XEXP (trial, 0), 0)) == LABEL_REF
                           && GET_CODE (XEXP (XEXP (trial, 0), 0)) == LABEL_REF
                           && GET_CODE (XEXP (XEXP (trial, 0), 1)) == LABEL_REF)))
                           && GET_CODE (XEXP (XEXP (trial, 0), 1)) == LABEL_REF)))
            /* Do nothing for this case.  */
            /* Do nothing for this case.  */
            ;
            ;
 
 
          /* Look for a substitution that makes a valid insn.  */
          /* Look for a substitution that makes a valid insn.  */
          else if (validate_change (insn, &SET_SRC (sets[i].rtl), trial, 0))
          else if (validate_change (insn, &SET_SRC (sets[i].rtl), trial, 0))
            {
            {
              rtx new = canon_reg (SET_SRC (sets[i].rtl), insn);
              rtx new = canon_reg (SET_SRC (sets[i].rtl), insn);
 
 
              /* If we just made a substitution inside a libcall, then we
              /* If we just made a substitution inside a libcall, then we
                 need to make the same substitution in any notes attached
                 need to make the same substitution in any notes attached
                 to the RETVAL insn.  */
                 to the RETVAL insn.  */
              if (libcall_insn
              if (libcall_insn
                  && (REG_P (sets[i].orig_src)
                  && (REG_P (sets[i].orig_src)
                      || GET_CODE (sets[i].orig_src) == SUBREG
                      || GET_CODE (sets[i].orig_src) == SUBREG
                      || MEM_P (sets[i].orig_src)))
                      || MEM_P (sets[i].orig_src)))
                {
                {
                  rtx note = find_reg_equal_equiv_note (libcall_insn);
                  rtx note = find_reg_equal_equiv_note (libcall_insn);
                  if (note != 0)
                  if (note != 0)
                    XEXP (note, 0) = simplify_replace_rtx (XEXP (note, 0),
                    XEXP (note, 0) = simplify_replace_rtx (XEXP (note, 0),
                                                           sets[i].orig_src,
                                                           sets[i].orig_src,
                                                           copy_rtx (new));
                                                           copy_rtx (new));
                }
                }
 
 
              /* The result of apply_change_group can be ignored; see
              /* The result of apply_change_group can be ignored; see
                 canon_reg.  */
                 canon_reg.  */
 
 
              validate_change (insn, &SET_SRC (sets[i].rtl), new, 1);
              validate_change (insn, &SET_SRC (sets[i].rtl), new, 1);
              apply_change_group ();
              apply_change_group ();
              break;
              break;
            }
            }
 
 
          /* If we previously found constant pool entries for
          /* If we previously found constant pool entries for
             constants and this is a constant, try making a
             constants and this is a constant, try making a
             pool entry.  Put it in src_folded unless we already have done
             pool entry.  Put it in src_folded unless we already have done
             this since that is where it likely came from.  */
             this since that is where it likely came from.  */
 
 
          else if (constant_pool_entries_cost
          else if (constant_pool_entries_cost
                   && CONSTANT_P (trial)
                   && CONSTANT_P (trial)
                   && (src_folded == 0
                   && (src_folded == 0
                       || (!MEM_P (src_folded)
                       || (!MEM_P (src_folded)
                           && ! src_folded_force_flag))
                           && ! src_folded_force_flag))
                   && GET_MODE_CLASS (mode) != MODE_CC
                   && GET_MODE_CLASS (mode) != MODE_CC
                   && mode != VOIDmode)
                   && mode != VOIDmode)
            {
            {
              src_folded_force_flag = 1;
              src_folded_force_flag = 1;
              src_folded = trial;
              src_folded = trial;
              src_folded_cost = constant_pool_entries_cost;
              src_folded_cost = constant_pool_entries_cost;
              src_folded_regcost = constant_pool_entries_regcost;
              src_folded_regcost = constant_pool_entries_regcost;
            }
            }
        }
        }
 
 
      src = SET_SRC (sets[i].rtl);
      src = SET_SRC (sets[i].rtl);
 
 
      /* In general, it is good to have a SET with SET_SRC == SET_DEST.
      /* In general, it is good to have a SET with SET_SRC == SET_DEST.
         However, there is an important exception:  If both are registers
         However, there is an important exception:  If both are registers
         that are not the head of their equivalence class, replace SET_SRC
         that are not the head of their equivalence class, replace SET_SRC
         with the head of the class.  If we do not do this, we will have
         with the head of the class.  If we do not do this, we will have
         both registers live over a portion of the basic block.  This way,
         both registers live over a portion of the basic block.  This way,
         their lifetimes will likely abut instead of overlapping.  */
         their lifetimes will likely abut instead of overlapping.  */
      if (REG_P (dest)
      if (REG_P (dest)
          && REGNO_QTY_VALID_P (REGNO (dest)))
          && REGNO_QTY_VALID_P (REGNO (dest)))
        {
        {
          int dest_q = REG_QTY (REGNO (dest));
          int dest_q = REG_QTY (REGNO (dest));
          struct qty_table_elem *dest_ent = &qty_table[dest_q];
          struct qty_table_elem *dest_ent = &qty_table[dest_q];
 
 
          if (dest_ent->mode == GET_MODE (dest)
          if (dest_ent->mode == GET_MODE (dest)
              && dest_ent->first_reg != REGNO (dest)
              && dest_ent->first_reg != REGNO (dest)
              && REG_P (src) && REGNO (src) == REGNO (dest)
              && REG_P (src) && REGNO (src) == REGNO (dest)
              /* Don't do this if the original insn had a hard reg as
              /* Don't do this if the original insn had a hard reg as
                 SET_SRC or SET_DEST.  */
                 SET_SRC or SET_DEST.  */
              && (!REG_P (sets[i].src)
              && (!REG_P (sets[i].src)
                  || REGNO (sets[i].src) >= FIRST_PSEUDO_REGISTER)
                  || REGNO (sets[i].src) >= FIRST_PSEUDO_REGISTER)
              && (!REG_P (dest) || REGNO (dest) >= FIRST_PSEUDO_REGISTER))
              && (!REG_P (dest) || REGNO (dest) >= FIRST_PSEUDO_REGISTER))
            /* We can't call canon_reg here because it won't do anything if
            /* We can't call canon_reg here because it won't do anything if
               SRC is a hard register.  */
               SRC is a hard register.  */
            {
            {
              int src_q = REG_QTY (REGNO (src));
              int src_q = REG_QTY (REGNO (src));
              struct qty_table_elem *src_ent = &qty_table[src_q];
              struct qty_table_elem *src_ent = &qty_table[src_q];
              int first = src_ent->first_reg;
              int first = src_ent->first_reg;
              rtx new_src
              rtx new_src
                = (first >= FIRST_PSEUDO_REGISTER
                = (first >= FIRST_PSEUDO_REGISTER
                   ? regno_reg_rtx[first] : gen_rtx_REG (GET_MODE (src), first));
                   ? regno_reg_rtx[first] : gen_rtx_REG (GET_MODE (src), first));
 
 
              /* We must use validate-change even for this, because this
              /* We must use validate-change even for this, because this
                 might be a special no-op instruction, suitable only to
                 might be a special no-op instruction, suitable only to
                 tag notes onto.  */
                 tag notes onto.  */
              if (validate_change (insn, &SET_SRC (sets[i].rtl), new_src, 0))
              if (validate_change (insn, &SET_SRC (sets[i].rtl), new_src, 0))
                {
                {
                  src = new_src;
                  src = new_src;
                  /* If we had a constant that is cheaper than what we are now
                  /* If we had a constant that is cheaper than what we are now
                     setting SRC to, use that constant.  We ignored it when we
                     setting SRC to, use that constant.  We ignored it when we
                     thought we could make this into a no-op.  */
                     thought we could make this into a no-op.  */
                  if (src_const && COST (src_const) < COST (src)
                  if (src_const && COST (src_const) < COST (src)
                      && validate_change (insn, &SET_SRC (sets[i].rtl),
                      && validate_change (insn, &SET_SRC (sets[i].rtl),
                                          src_const, 0))
                                          src_const, 0))
                    src = src_const;
                    src = src_const;
                }
                }
            }
            }
        }
        }
 
 
      /* If we made a change, recompute SRC values.  */
      /* If we made a change, recompute SRC values.  */
      if (src != sets[i].src)
      if (src != sets[i].src)
        {
        {
          cse_altered = 1;
          cse_altered = 1;
          do_not_record = 0;
          do_not_record = 0;
          hash_arg_in_memory = 0;
          hash_arg_in_memory = 0;
          sets[i].src = src;
          sets[i].src = src;
          sets[i].src_hash = HASH (src, mode);
          sets[i].src_hash = HASH (src, mode);
          sets[i].src_volatile = do_not_record;
          sets[i].src_volatile = do_not_record;
          sets[i].src_in_memory = hash_arg_in_memory;
          sets[i].src_in_memory = hash_arg_in_memory;
          sets[i].src_elt = lookup (src, sets[i].src_hash, mode);
          sets[i].src_elt = lookup (src, sets[i].src_hash, mode);
        }
        }
 
 
      /* If this is a single SET, we are setting a register, and we have an
      /* If this is a single SET, we are setting a register, and we have an
         equivalent constant, we want to add a REG_NOTE.   We don't want
         equivalent constant, we want to add a REG_NOTE.   We don't want
         to write a REG_EQUAL note for a constant pseudo since verifying that
         to write a REG_EQUAL note for a constant pseudo since verifying that
         that pseudo hasn't been eliminated is a pain.  Such a note also
         that pseudo hasn't been eliminated is a pain.  Such a note also
         won't help anything.
         won't help anything.
 
 
         Avoid a REG_EQUAL note for (CONST (MINUS (LABEL_REF) (LABEL_REF)))
         Avoid a REG_EQUAL note for (CONST (MINUS (LABEL_REF) (LABEL_REF)))
         which can be created for a reference to a compile time computable
         which can be created for a reference to a compile time computable
         entry in a jump table.  */
         entry in a jump table.  */
 
 
      if (n_sets == 1 && src_const && REG_P (dest)
      if (n_sets == 1 && src_const && REG_P (dest)
          && !REG_P (src_const)
          && !REG_P (src_const)
          && ! (GET_CODE (src_const) == CONST
          && ! (GET_CODE (src_const) == CONST
                && GET_CODE (XEXP (src_const, 0)) == MINUS
                && GET_CODE (XEXP (src_const, 0)) == MINUS
                && GET_CODE (XEXP (XEXP (src_const, 0), 0)) == LABEL_REF
                && GET_CODE (XEXP (XEXP (src_const, 0), 0)) == LABEL_REF
                && GET_CODE (XEXP (XEXP (src_const, 0), 1)) == LABEL_REF))
                && GET_CODE (XEXP (XEXP (src_const, 0), 1)) == LABEL_REF))
        {
        {
          /* We only want a REG_EQUAL note if src_const != src.  */
          /* We only want a REG_EQUAL note if src_const != src.  */
          if (! rtx_equal_p (src, src_const))
          if (! rtx_equal_p (src, src_const))
            {
            {
              /* Make sure that the rtx is not shared.  */
              /* Make sure that the rtx is not shared.  */
              src_const = copy_rtx (src_const);
              src_const = copy_rtx (src_const);
 
 
              /* Record the actual constant value in a REG_EQUAL note,
              /* Record the actual constant value in a REG_EQUAL note,
                 making a new one if one does not already exist.  */
                 making a new one if one does not already exist.  */
              set_unique_reg_note (insn, REG_EQUAL, src_const);
              set_unique_reg_note (insn, REG_EQUAL, src_const);
            }
            }
        }
        }
 
 
      /* Now deal with the destination.  */
      /* Now deal with the destination.  */
      do_not_record = 0;
      do_not_record = 0;
 
 
      /* Look within any ZERO_EXTRACT to the MEM or REG within it.  */
      /* Look within any ZERO_EXTRACT to the MEM or REG within it.  */
      while (GET_CODE (dest) == SUBREG
      while (GET_CODE (dest) == SUBREG
             || GET_CODE (dest) == ZERO_EXTRACT
             || GET_CODE (dest) == ZERO_EXTRACT
             || GET_CODE (dest) == STRICT_LOW_PART)
             || GET_CODE (dest) == STRICT_LOW_PART)
        dest = XEXP (dest, 0);
        dest = XEXP (dest, 0);
 
 
      sets[i].inner_dest = dest;
      sets[i].inner_dest = dest;
 
 
      if (MEM_P (dest))
      if (MEM_P (dest))
        {
        {
#ifdef PUSH_ROUNDING
#ifdef PUSH_ROUNDING
          /* Stack pushes invalidate the stack pointer.  */
          /* Stack pushes invalidate the stack pointer.  */
          rtx addr = XEXP (dest, 0);
          rtx addr = XEXP (dest, 0);
          if (GET_RTX_CLASS (GET_CODE (addr)) == RTX_AUTOINC
          if (GET_RTX_CLASS (GET_CODE (addr)) == RTX_AUTOINC
              && XEXP (addr, 0) == stack_pointer_rtx)
              && XEXP (addr, 0) == stack_pointer_rtx)
            invalidate (stack_pointer_rtx, VOIDmode);
            invalidate (stack_pointer_rtx, VOIDmode);
#endif
#endif
          dest = fold_rtx (dest, insn);
          dest = fold_rtx (dest, insn);
        }
        }
 
 
      /* Compute the hash code of the destination now,
      /* Compute the hash code of the destination now,
         before the effects of this instruction are recorded,
         before the effects of this instruction are recorded,
         since the register values used in the address computation
         since the register values used in the address computation
         are those before this instruction.  */
         are those before this instruction.  */
      sets[i].dest_hash = HASH (dest, mode);
      sets[i].dest_hash = HASH (dest, mode);
 
 
      /* Don't enter a bit-field in the hash table
      /* Don't enter a bit-field in the hash table
         because the value in it after the store
         because the value in it after the store
         may not equal what was stored, due to truncation.  */
         may not equal what was stored, due to truncation.  */
 
 
      if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT)
      if (GET_CODE (SET_DEST (sets[i].rtl)) == ZERO_EXTRACT)
        {
        {
          rtx width = XEXP (SET_DEST (sets[i].rtl), 1);
          rtx width = XEXP (SET_DEST (sets[i].rtl), 1);
 
 
          if (src_const != 0 && GET_CODE (src_const) == CONST_INT
          if (src_const != 0 && GET_CODE (src_const) == CONST_INT
              && GET_CODE (width) == CONST_INT
              && GET_CODE (width) == CONST_INT
              && INTVAL (width) < HOST_BITS_PER_WIDE_INT
              && INTVAL (width) < HOST_BITS_PER_WIDE_INT
              && ! (INTVAL (src_const)
              && ! (INTVAL (src_const)
                    & ((HOST_WIDE_INT) (-1) << INTVAL (width))))
                    & ((HOST_WIDE_INT) (-1) << INTVAL (width))))
            /* Exception: if the value is constant,
            /* Exception: if the value is constant,
               and it won't be truncated, record it.  */
               and it won't be truncated, record it.  */
            ;
            ;
          else
          else
            {
            {
              /* This is chosen so that the destination will be invalidated
              /* This is chosen so that the destination will be invalidated
                 but no new value will be recorded.
                 but no new value will be recorded.
                 We must invalidate because sometimes constant
                 We must invalidate because sometimes constant
                 values can be recorded for bitfields.  */
                 values can be recorded for bitfields.  */
              sets[i].src_elt = 0;
              sets[i].src_elt = 0;
              sets[i].src_volatile = 1;
              sets[i].src_volatile = 1;
              src_eqv = 0;
              src_eqv = 0;
              src_eqv_elt = 0;
              src_eqv_elt = 0;
            }
            }
        }
        }
 
 
      /* If only one set in a JUMP_INSN and it is now a no-op, we can delete
      /* If only one set in a JUMP_INSN and it is now a no-op, we can delete
         the insn.  */
         the insn.  */
      else if (n_sets == 1 && dest == pc_rtx && src == pc_rtx)
      else if (n_sets == 1 && dest == pc_rtx && src == pc_rtx)
        {
        {
          /* One less use of the label this insn used to jump to.  */
          /* One less use of the label this insn used to jump to.  */
          delete_insn (insn);
          delete_insn (insn);
          cse_jumps_altered = 1;
          cse_jumps_altered = 1;
          /* No more processing for this set.  */
          /* No more processing for this set.  */
          sets[i].rtl = 0;
          sets[i].rtl = 0;
        }
        }
 
 
      /* If this SET is now setting PC to a label, we know it used to
      /* If this SET is now setting PC to a label, we know it used to
         be a conditional or computed branch.  */
         be a conditional or computed branch.  */
      else if (dest == pc_rtx && GET_CODE (src) == LABEL_REF
      else if (dest == pc_rtx && GET_CODE (src) == LABEL_REF
               && !LABEL_REF_NONLOCAL_P (src))
               && !LABEL_REF_NONLOCAL_P (src))
        {
        {
          /* Now emit a BARRIER after the unconditional jump.  */
          /* Now emit a BARRIER after the unconditional jump.  */
          if (NEXT_INSN (insn) == 0
          if (NEXT_INSN (insn) == 0
              || !BARRIER_P (NEXT_INSN (insn)))
              || !BARRIER_P (NEXT_INSN (insn)))
            emit_barrier_after (insn);
            emit_barrier_after (insn);
 
 
          /* We reemit the jump in as many cases as possible just in
          /* We reemit the jump in as many cases as possible just in
             case the form of an unconditional jump is significantly
             case the form of an unconditional jump is significantly
             different than a computed jump or conditional jump.
             different than a computed jump or conditional jump.
 
 
             If this insn has multiple sets, then reemitting the
             If this insn has multiple sets, then reemitting the
             jump is nontrivial.  So instead we just force rerecognition
             jump is nontrivial.  So instead we just force rerecognition
             and hope for the best.  */
             and hope for the best.  */
          if (n_sets == 1)
          if (n_sets == 1)
            {
            {
              rtx new, note;
              rtx new, note;
 
 
              new = emit_jump_insn_after (gen_jump (XEXP (src, 0)), insn);
              new = emit_jump_insn_after (gen_jump (XEXP (src, 0)), insn);
              JUMP_LABEL (new) = XEXP (src, 0);
              JUMP_LABEL (new) = XEXP (src, 0);
              LABEL_NUSES (XEXP (src, 0))++;
              LABEL_NUSES (XEXP (src, 0))++;
 
 
              /* Make sure to copy over REG_NON_LOCAL_GOTO.  */
              /* Make sure to copy over REG_NON_LOCAL_GOTO.  */
              note = find_reg_note (insn, REG_NON_LOCAL_GOTO, 0);
              note = find_reg_note (insn, REG_NON_LOCAL_GOTO, 0);
              if (note)
              if (note)
                {
                {
                  XEXP (note, 1) = NULL_RTX;
                  XEXP (note, 1) = NULL_RTX;
                  REG_NOTES (new) = note;
                  REG_NOTES (new) = note;
                }
                }
 
 
              delete_insn (insn);
              delete_insn (insn);
              insn = new;
              insn = new;
 
 
              /* Now emit a BARRIER after the unconditional jump.  */
              /* Now emit a BARRIER after the unconditional jump.  */
              if (NEXT_INSN (insn) == 0
              if (NEXT_INSN (insn) == 0
                  || !BARRIER_P (NEXT_INSN (insn)))
                  || !BARRIER_P (NEXT_INSN (insn)))
                emit_barrier_after (insn);
                emit_barrier_after (insn);
            }
            }
          else
          else
            INSN_CODE (insn) = -1;
            INSN_CODE (insn) = -1;
 
 
          /* Do not bother deleting any unreachable code,
          /* Do not bother deleting any unreachable code,
             let jump/flow do that.  */
             let jump/flow do that.  */
 
 
          cse_jumps_altered = 1;
          cse_jumps_altered = 1;
          sets[i].rtl = 0;
          sets[i].rtl = 0;
        }
        }
 
 
      /* If destination is volatile, invalidate it and then do no further
      /* If destination is volatile, invalidate it and then do no further
         processing for this assignment.  */
         processing for this assignment.  */
 
 
      else if (do_not_record)
      else if (do_not_record)
        {
        {
          if (REG_P (dest) || GET_CODE (dest) == SUBREG)
          if (REG_P (dest) || GET_CODE (dest) == SUBREG)
            invalidate (dest, VOIDmode);
            invalidate (dest, VOIDmode);
          else if (MEM_P (dest))
          else if (MEM_P (dest))
            invalidate (dest, VOIDmode);
            invalidate (dest, VOIDmode);
          else if (GET_CODE (dest) == STRICT_LOW_PART
          else if (GET_CODE (dest) == STRICT_LOW_PART
                   || GET_CODE (dest) == ZERO_EXTRACT)
                   || GET_CODE (dest) == ZERO_EXTRACT)
            invalidate (XEXP (dest, 0), GET_MODE (dest));
            invalidate (XEXP (dest, 0), GET_MODE (dest));
          sets[i].rtl = 0;
          sets[i].rtl = 0;
        }
        }
 
 
      if (sets[i].rtl != 0 && dest != SET_DEST (sets[i].rtl))
      if (sets[i].rtl != 0 && dest != SET_DEST (sets[i].rtl))
        sets[i].dest_hash = HASH (SET_DEST (sets[i].rtl), mode);
        sets[i].dest_hash = HASH (SET_DEST (sets[i].rtl), mode);
 
 
#ifdef HAVE_cc0
#ifdef HAVE_cc0
      /* If setting CC0, record what it was set to, or a constant, if it
      /* If setting CC0, record what it was set to, or a constant, if it
         is equivalent to a constant.  If it is being set to a floating-point
         is equivalent to a constant.  If it is being set to a floating-point
         value, make a COMPARE with the appropriate constant of 0.  If we
         value, make a COMPARE with the appropriate constant of 0.  If we
         don't do this, later code can interpret this as a test against
         don't do this, later code can interpret this as a test against
         const0_rtx, which can cause problems if we try to put it into an
         const0_rtx, which can cause problems if we try to put it into an
         insn as a floating-point operand.  */
         insn as a floating-point operand.  */
      if (dest == cc0_rtx)
      if (dest == cc0_rtx)
        {
        {
          this_insn_cc0 = src_const && mode != VOIDmode ? src_const : src;
          this_insn_cc0 = src_const && mode != VOIDmode ? src_const : src;
          this_insn_cc0_mode = mode;
          this_insn_cc0_mode = mode;
          if (FLOAT_MODE_P (mode))
          if (FLOAT_MODE_P (mode))
            this_insn_cc0 = gen_rtx_COMPARE (VOIDmode, this_insn_cc0,
            this_insn_cc0 = gen_rtx_COMPARE (VOIDmode, this_insn_cc0,
                                             CONST0_RTX (mode));
                                             CONST0_RTX (mode));
        }
        }
#endif
#endif
    }
    }
 
 
  /* Now enter all non-volatile source expressions in the hash table
  /* Now enter all non-volatile source expressions in the hash table
     if they are not already present.
     if they are not already present.
     Record their equivalence classes in src_elt.
     Record their equivalence classes in src_elt.
     This way we can insert the corresponding destinations into
     This way we can insert the corresponding destinations into
     the same classes even if the actual sources are no longer in them
     the same classes even if the actual sources are no longer in them
     (having been invalidated).  */
     (having been invalidated).  */
 
 
  if (src_eqv && src_eqv_elt == 0 && sets[0].rtl != 0 && ! src_eqv_volatile
  if (src_eqv && src_eqv_elt == 0 && sets[0].rtl != 0 && ! src_eqv_volatile
      && ! rtx_equal_p (src_eqv, SET_DEST (sets[0].rtl)))
      && ! rtx_equal_p (src_eqv, SET_DEST (sets[0].rtl)))
    {
    {
      struct table_elt *elt;
      struct table_elt *elt;
      struct table_elt *classp = sets[0].src_elt;
      struct table_elt *classp = sets[0].src_elt;
      rtx dest = SET_DEST (sets[0].rtl);
      rtx dest = SET_DEST (sets[0].rtl);
      enum machine_mode eqvmode = GET_MODE (dest);
      enum machine_mode eqvmode = GET_MODE (dest);
 
 
      if (GET_CODE (dest) == STRICT_LOW_PART)
      if (GET_CODE (dest) == STRICT_LOW_PART)
        {
        {
          eqvmode = GET_MODE (SUBREG_REG (XEXP (dest, 0)));
          eqvmode = GET_MODE (SUBREG_REG (XEXP (dest, 0)));
          classp = 0;
          classp = 0;
        }
        }
      if (insert_regs (src_eqv, classp, 0))
      if (insert_regs (src_eqv, classp, 0))
        {
        {
          rehash_using_reg (src_eqv);
          rehash_using_reg (src_eqv);
          src_eqv_hash = HASH (src_eqv, eqvmode);
          src_eqv_hash = HASH (src_eqv, eqvmode);
        }
        }
      elt = insert (src_eqv, classp, src_eqv_hash, eqvmode);
      elt = insert (src_eqv, classp, src_eqv_hash, eqvmode);
      elt->in_memory = src_eqv_in_memory;
      elt->in_memory = src_eqv_in_memory;
      src_eqv_elt = elt;
      src_eqv_elt = elt;
 
 
      /* Check to see if src_eqv_elt is the same as a set source which
      /* Check to see if src_eqv_elt is the same as a set source which
         does not yet have an elt, and if so set the elt of the set source
         does not yet have an elt, and if so set the elt of the set source
         to src_eqv_elt.  */
         to src_eqv_elt.  */
      for (i = 0; i < n_sets; i++)
      for (i = 0; i < n_sets; i++)
        if (sets[i].rtl && sets[i].src_elt == 0
        if (sets[i].rtl && sets[i].src_elt == 0
            && rtx_equal_p (SET_SRC (sets[i].rtl), src_eqv))
            && rtx_equal_p (SET_SRC (sets[i].rtl), src_eqv))
          sets[i].src_elt = src_eqv_elt;
          sets[i].src_elt = src_eqv_elt;
    }
    }
 
 
  for (i = 0; i < n_sets; i++)
  for (i = 0; i < n_sets; i++)
    if (sets[i].rtl && ! sets[i].src_volatile
    if (sets[i].rtl && ! sets[i].src_volatile
        && ! rtx_equal_p (SET_SRC (sets[i].rtl), SET_DEST (sets[i].rtl)))
        && ! rtx_equal_p (SET_SRC (sets[i].rtl), SET_DEST (sets[i].rtl)))
      {
      {
        if (GET_CODE (SET_DEST (sets[i].rtl)) == STRICT_LOW_PART)
        if (GET_CODE (SET_DEST (sets[i].rtl)) == STRICT_LOW_PART)
          {
          {
            /* REG_EQUAL in setting a STRICT_LOW_PART
            /* REG_EQUAL in setting a STRICT_LOW_PART
               gives an equivalent for the entire destination register,
               gives an equivalent for the entire destination register,
               not just for the subreg being stored in now.
               not just for the subreg being stored in now.
               This is a more interesting equivalence, so we arrange later
               This is a more interesting equivalence, so we arrange later
               to treat the entire reg as the destination.  */
               to treat the entire reg as the destination.  */
            sets[i].src_elt = src_eqv_elt;
            sets[i].src_elt = src_eqv_elt;
            sets[i].src_hash = src_eqv_hash;
            sets[i].src_hash = src_eqv_hash;
          }
          }
        else
        else
          {
          {
            /* Insert source and constant equivalent into hash table, if not
            /* Insert source and constant equivalent into hash table, if not
               already present.  */
               already present.  */
            struct table_elt *classp = src_eqv_elt;
            struct table_elt *classp = src_eqv_elt;
            rtx src = sets[i].src;
            rtx src = sets[i].src;
            rtx dest = SET_DEST (sets[i].rtl);
            rtx dest = SET_DEST (sets[i].rtl);
            enum machine_mode mode
            enum machine_mode mode
              = GET_MODE (src) == VOIDmode ? GET_MODE (dest) : GET_MODE (src);
              = GET_MODE (src) == VOIDmode ? GET_MODE (dest) : GET_MODE (src);
 
 
            /* It's possible that we have a source value known to be
            /* It's possible that we have a source value known to be
               constant but don't have a REG_EQUAL note on the insn.
               constant but don't have a REG_EQUAL note on the insn.
               Lack of a note will mean src_eqv_elt will be NULL.  This
               Lack of a note will mean src_eqv_elt will be NULL.  This
               can happen where we've generated a SUBREG to access a
               can happen where we've generated a SUBREG to access a
               CONST_INT that is already in a register in a wider mode.
               CONST_INT that is already in a register in a wider mode.
               Ensure that the source expression is put in the proper
               Ensure that the source expression is put in the proper
               constant class.  */
               constant class.  */
            if (!classp)
            if (!classp)
              classp = sets[i].src_const_elt;
              classp = sets[i].src_const_elt;
 
 
            if (sets[i].src_elt == 0)
            if (sets[i].src_elt == 0)
              {
              {
                /* Don't put a hard register source into the table if this is
                /* Don't put a hard register source into the table if this is
                   the last insn of a libcall.  In this case, we only need
                   the last insn of a libcall.  In this case, we only need
                   to put src_eqv_elt in src_elt.  */
                   to put src_eqv_elt in src_elt.  */
                if (! find_reg_note (insn, REG_RETVAL, NULL_RTX))
                if (! find_reg_note (insn, REG_RETVAL, NULL_RTX))
                  {
                  {
                    struct table_elt *elt;
                    struct table_elt *elt;
 
 
                    /* Note that these insert_regs calls cannot remove
                    /* Note that these insert_regs calls cannot remove
                       any of the src_elt's, because they would have failed to
                       any of the src_elt's, because they would have failed to
                       match if not still valid.  */
                       match if not still valid.  */
                    if (insert_regs (src, classp, 0))
                    if (insert_regs (src, classp, 0))
                      {
                      {
                        rehash_using_reg (src);
                        rehash_using_reg (src);
                        sets[i].src_hash = HASH (src, mode);
                        sets[i].src_hash = HASH (src, mode);
                      }
                      }
                    elt = insert (src, classp, sets[i].src_hash, mode);
                    elt = insert (src, classp, sets[i].src_hash, mode);
                    elt->in_memory = sets[i].src_in_memory;
                    elt->in_memory = sets[i].src_in_memory;
                    sets[i].src_elt = classp = elt;
                    sets[i].src_elt = classp = elt;
                  }
                  }
                else
                else
                  sets[i].src_elt = classp;
                  sets[i].src_elt = classp;
              }
              }
            if (sets[i].src_const && sets[i].src_const_elt == 0
            if (sets[i].src_const && sets[i].src_const_elt == 0
                && src != sets[i].src_const
                && src != sets[i].src_const
                && ! rtx_equal_p (sets[i].src_const, src))
                && ! rtx_equal_p (sets[i].src_const, src))
              sets[i].src_elt = insert (sets[i].src_const, classp,
              sets[i].src_elt = insert (sets[i].src_const, classp,
                                        sets[i].src_const_hash, mode);
                                        sets[i].src_const_hash, mode);
          }
          }
      }
      }
    else if (sets[i].src_elt == 0)
    else if (sets[i].src_elt == 0)
      /* If we did not insert the source into the hash table (e.g., it was
      /* If we did not insert the source into the hash table (e.g., it was
         volatile), note the equivalence class for the REG_EQUAL value, if any,
         volatile), note the equivalence class for the REG_EQUAL value, if any,
         so that the destination goes into that class.  */
         so that the destination goes into that class.  */
      sets[i].src_elt = src_eqv_elt;
      sets[i].src_elt = src_eqv_elt;
 
 
  /* Record destination addresses in the hash table.  This allows us to
  /* Record destination addresses in the hash table.  This allows us to
     check if they are invalidated by other sets.  */
     check if they are invalidated by other sets.  */
  for (i = 0; i < n_sets; i++)
  for (i = 0; i < n_sets; i++)
    {
    {
      if (sets[i].rtl)
      if (sets[i].rtl)
        {
        {
          rtx x = sets[i].inner_dest;
          rtx x = sets[i].inner_dest;
          struct table_elt *elt;
          struct table_elt *elt;
          enum machine_mode mode;
          enum machine_mode mode;
          unsigned hash;
          unsigned hash;
 
 
          if (MEM_P (x))
          if (MEM_P (x))
            {
            {
              x = XEXP (x, 0);
              x = XEXP (x, 0);
              mode = GET_MODE (x);
              mode = GET_MODE (x);
              hash = HASH (x, mode);
              hash = HASH (x, mode);
              elt = lookup (x, hash, mode);
              elt = lookup (x, hash, mode);
              if (!elt)
              if (!elt)
                {
                {
                  if (insert_regs (x, NULL, 0))
                  if (insert_regs (x, NULL, 0))
                    {
                    {
                      rtx dest = SET_DEST (sets[i].rtl);
                      rtx dest = SET_DEST (sets[i].rtl);
 
 
                      rehash_using_reg (x);
                      rehash_using_reg (x);
                      hash = HASH (x, mode);
                      hash = HASH (x, mode);
                      sets[i].dest_hash = HASH (dest, GET_MODE (dest));
                      sets[i].dest_hash = HASH (dest, GET_MODE (dest));
                    }
                    }
                  elt = insert (x, NULL, hash, mode);
                  elt = insert (x, NULL, hash, mode);
                }
                }
 
 
              sets[i].dest_addr_elt = elt;
              sets[i].dest_addr_elt = elt;
            }
            }
          else
          else
            sets[i].dest_addr_elt = NULL;
            sets[i].dest_addr_elt = NULL;
        }
        }
    }
    }
 
 
  invalidate_from_clobbers (x);
  invalidate_from_clobbers (x);
 
 
  /* Some registers are invalidated by subroutine calls.  Memory is
  /* Some registers are invalidated by subroutine calls.  Memory is
     invalidated by non-constant calls.  */
     invalidated by non-constant calls.  */
 
 
  if (CALL_P (insn))
  if (CALL_P (insn))
    {
    {
      if (! CONST_OR_PURE_CALL_P (insn))
      if (! CONST_OR_PURE_CALL_P (insn))
        invalidate_memory ();
        invalidate_memory ();
      invalidate_for_call ();
      invalidate_for_call ();
    }
    }
 
 
  /* Now invalidate everything set by this instruction.
  /* Now invalidate everything set by this instruction.
     If a SUBREG or other funny destination is being set,
     If a SUBREG or other funny destination is being set,
     sets[i].rtl is still nonzero, so here we invalidate the reg
     sets[i].rtl is still nonzero, so here we invalidate the reg
     a part of which is being set.  */
     a part of which is being set.  */
 
 
  for (i = 0; i < n_sets; i++)
  for (i = 0; i < n_sets; i++)
    if (sets[i].rtl)
    if (sets[i].rtl)
      {
      {
        /* We can't use the inner dest, because the mode associated with
        /* We can't use the inner dest, because the mode associated with
           a ZERO_EXTRACT is significant.  */
           a ZERO_EXTRACT is significant.  */
        rtx dest = SET_DEST (sets[i].rtl);
        rtx dest = SET_DEST (sets[i].rtl);
 
 
        /* Needed for registers to remove the register from its
        /* Needed for registers to remove the register from its
           previous quantity's chain.
           previous quantity's chain.
           Needed for memory if this is a nonvarying address, unless
           Needed for memory if this is a nonvarying address, unless
           we have just done an invalidate_memory that covers even those.  */
           we have just done an invalidate_memory that covers even those.  */
        if (REG_P (dest) || GET_CODE (dest) == SUBREG)
        if (REG_P (dest) || GET_CODE (dest) == SUBREG)
          invalidate (dest, VOIDmode);
          invalidate (dest, VOIDmode);
        else if (MEM_P (dest))
        else if (MEM_P (dest))
          invalidate (dest, VOIDmode);
          invalidate (dest, VOIDmode);
        else if (GET_CODE (dest) == STRICT_LOW_PART
        else if (GET_CODE (dest) == STRICT_LOW_PART
                 || GET_CODE (dest) == ZERO_EXTRACT)
                 || GET_CODE (dest) == ZERO_EXTRACT)
          invalidate (XEXP (dest, 0), GET_MODE (dest));
          invalidate (XEXP (dest, 0), GET_MODE (dest));
      }
      }
 
 
  /* A volatile ASM invalidates everything.  */
  /* A volatile ASM invalidates everything.  */
  if (NONJUMP_INSN_P (insn)
  if (NONJUMP_INSN_P (insn)
      && GET_CODE (PATTERN (insn)) == ASM_OPERANDS
      && GET_CODE (PATTERN (insn)) == ASM_OPERANDS
      && MEM_VOLATILE_P (PATTERN (insn)))
      && MEM_VOLATILE_P (PATTERN (insn)))
    flush_hash_table ();
    flush_hash_table ();
 
 
  /* Make sure registers mentioned in destinations
  /* Make sure registers mentioned in destinations
     are safe for use in an expression to be inserted.
     are safe for use in an expression to be inserted.
     This removes from the hash table
     This removes from the hash table
     any invalid entry that refers to one of these registers.
     any invalid entry that refers to one of these registers.
 
 
     We don't care about the return value from mention_regs because
     We don't care about the return value from mention_regs because
     we are going to hash the SET_DEST values unconditionally.  */
     we are going to hash the SET_DEST values unconditionally.  */
 
 
  for (i = 0; i < n_sets; i++)
  for (i = 0; i < n_sets; i++)
    {
    {
      if (sets[i].rtl)
      if (sets[i].rtl)
        {
        {
          rtx x = SET_DEST (sets[i].rtl);
          rtx x = SET_DEST (sets[i].rtl);
 
 
          if (!REG_P (x))
          if (!REG_P (x))
            mention_regs (x);
            mention_regs (x);
          else
          else
            {
            {
              /* We used to rely on all references to a register becoming
              /* We used to rely on all references to a register becoming
                 inaccessible when a register changes to a new quantity,
                 inaccessible when a register changes to a new quantity,
                 since that changes the hash code.  However, that is not
                 since that changes the hash code.  However, that is not
                 safe, since after HASH_SIZE new quantities we get a
                 safe, since after HASH_SIZE new quantities we get a
                 hash 'collision' of a register with its own invalid
                 hash 'collision' of a register with its own invalid
                 entries.  And since SUBREGs have been changed not to
                 entries.  And since SUBREGs have been changed not to
                 change their hash code with the hash code of the register,
                 change their hash code with the hash code of the register,
                 it wouldn't work any longer at all.  So we have to check
                 it wouldn't work any longer at all.  So we have to check
                 for any invalid references lying around now.
                 for any invalid references lying around now.
                 This code is similar to the REG case in mention_regs,
                 This code is similar to the REG case in mention_regs,
                 but it knows that reg_tick has been incremented, and
                 but it knows that reg_tick has been incremented, and
                 it leaves reg_in_table as -1 .  */
                 it leaves reg_in_table as -1 .  */
              unsigned int regno = REGNO (x);
              unsigned int regno = REGNO (x);
              unsigned int endregno
              unsigned int endregno
                = regno + (regno >= FIRST_PSEUDO_REGISTER ? 1
                = regno + (regno >= FIRST_PSEUDO_REGISTER ? 1
                           : hard_regno_nregs[regno][GET_MODE (x)]);
                           : hard_regno_nregs[regno][GET_MODE (x)]);
              unsigned int i;
              unsigned int i;
 
 
              for (i = regno; i < endregno; i++)
              for (i = regno; i < endregno; i++)
                {
                {
                  if (REG_IN_TABLE (i) >= 0)
                  if (REG_IN_TABLE (i) >= 0)
                    {
                    {
                      remove_invalid_refs (i);
                      remove_invalid_refs (i);
                      REG_IN_TABLE (i) = -1;
                      REG_IN_TABLE (i) = -1;
                    }
                    }
                }
                }
            }
            }
        }
        }
    }
    }
 
 
  /* We may have just removed some of the src_elt's from the hash table.
  /* We may have just removed some of the src_elt's from the hash table.
     So replace each one with the current head of the same class.
     So replace each one with the current head of the same class.
     Also check if destination addresses have been removed.  */
     Also check if destination addresses have been removed.  */
 
 
  for (i = 0; i < n_sets; i++)
  for (i = 0; i < n_sets; i++)
    if (sets[i].rtl)
    if (sets[i].rtl)
      {
      {
        if (sets[i].dest_addr_elt
        if (sets[i].dest_addr_elt
            && sets[i].dest_addr_elt->first_same_value == 0)
            && sets[i].dest_addr_elt->first_same_value == 0)
          {
          {
            /* The elt was removed, which means this destination is not
            /* The elt was removed, which means this destination is not
               valid after this instruction.  */
               valid after this instruction.  */
            sets[i].rtl = NULL_RTX;
            sets[i].rtl = NULL_RTX;
          }
          }
        else if (sets[i].src_elt && sets[i].src_elt->first_same_value == 0)
        else if (sets[i].src_elt && sets[i].src_elt->first_same_value == 0)
          /* If elt was removed, find current head of same class,
          /* If elt was removed, find current head of same class,
             or 0 if nothing remains of that class.  */
             or 0 if nothing remains of that class.  */
          {
          {
            struct table_elt *elt = sets[i].src_elt;
            struct table_elt *elt = sets[i].src_elt;
 
 
            while (elt && elt->prev_same_value)
            while (elt && elt->prev_same_value)
              elt = elt->prev_same_value;
              elt = elt->prev_same_value;
 
 
            while (elt && elt->first_same_value == 0)
            while (elt && elt->first_same_value == 0)
              elt = elt->next_same_value;
              elt = elt->next_same_value;
            sets[i].src_elt = elt ? elt->first_same_value : 0;
            sets[i].src_elt = elt ? elt->first_same_value : 0;
          }
          }
      }
      }
 
 
  /* Now insert the destinations into their equivalence classes.  */
  /* Now insert the destinations into their equivalence classes.  */
 
 
  for (i = 0; i < n_sets; i++)
  for (i = 0; i < n_sets; i++)
    if (sets[i].rtl)
    if (sets[i].rtl)
      {
      {
        rtx dest = SET_DEST (sets[i].rtl);
        rtx dest = SET_DEST (sets[i].rtl);
        struct table_elt *elt;
        struct table_elt *elt;
 
 
        /* Don't record value if we are not supposed to risk allocating
        /* Don't record value if we are not supposed to risk allocating
           floating-point values in registers that might be wider than
           floating-point values in registers that might be wider than
           memory.  */
           memory.  */
        if ((flag_float_store
        if ((flag_float_store
             && MEM_P (dest)
             && MEM_P (dest)
             && FLOAT_MODE_P (GET_MODE (dest)))
             && FLOAT_MODE_P (GET_MODE (dest)))
            /* Don't record BLKmode values, because we don't know the
            /* Don't record BLKmode values, because we don't know the
               size of it, and can't be sure that other BLKmode values
               size of it, and can't be sure that other BLKmode values
               have the same or smaller size.  */
               have the same or smaller size.  */
            || GET_MODE (dest) == BLKmode
            || GET_MODE (dest) == BLKmode
            /* Don't record values of destinations set inside a libcall block
            /* Don't record values of destinations set inside a libcall block
               since we might delete the libcall.  Things should have been set
               since we might delete the libcall.  Things should have been set
               up so we won't want to reuse such a value, but we play it safe
               up so we won't want to reuse such a value, but we play it safe
               here.  */
               here.  */
            || libcall_insn
            || libcall_insn
            /* If we didn't put a REG_EQUAL value or a source into the hash
            /* If we didn't put a REG_EQUAL value or a source into the hash
               table, there is no point is recording DEST.  */
               table, there is no point is recording DEST.  */
            || sets[i].src_elt == 0
            || sets[i].src_elt == 0
            /* If DEST is a paradoxical SUBREG and SRC is a ZERO_EXTEND
            /* If DEST is a paradoxical SUBREG and SRC is a ZERO_EXTEND
               or SIGN_EXTEND, don't record DEST since it can cause
               or SIGN_EXTEND, don't record DEST since it can cause
               some tracking to be wrong.
               some tracking to be wrong.
 
 
               ??? Think about this more later.  */
               ??? Think about this more later.  */
            || (GET_CODE (dest) == SUBREG
            || (GET_CODE (dest) == SUBREG
                && (GET_MODE_SIZE (GET_MODE (dest))
                && (GET_MODE_SIZE (GET_MODE (dest))
                    > GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))))
                    > GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))))
                && (GET_CODE (sets[i].src) == SIGN_EXTEND
                && (GET_CODE (sets[i].src) == SIGN_EXTEND
                    || GET_CODE (sets[i].src) == ZERO_EXTEND)))
                    || GET_CODE (sets[i].src) == ZERO_EXTEND)))
          continue;
          continue;
 
 
        /* STRICT_LOW_PART isn't part of the value BEING set,
        /* STRICT_LOW_PART isn't part of the value BEING set,
           and neither is the SUBREG inside it.
           and neither is the SUBREG inside it.
           Note that in this case SETS[I].SRC_ELT is really SRC_EQV_ELT.  */
           Note that in this case SETS[I].SRC_ELT is really SRC_EQV_ELT.  */
        if (GET_CODE (dest) == STRICT_LOW_PART)
        if (GET_CODE (dest) == STRICT_LOW_PART)
          dest = SUBREG_REG (XEXP (dest, 0));
          dest = SUBREG_REG (XEXP (dest, 0));
 
 
        if (REG_P (dest) || GET_CODE (dest) == SUBREG)
        if (REG_P (dest) || GET_CODE (dest) == SUBREG)
          /* Registers must also be inserted into chains for quantities.  */
          /* Registers must also be inserted into chains for quantities.  */
          if (insert_regs (dest, sets[i].src_elt, 1))
          if (insert_regs (dest, sets[i].src_elt, 1))
            {
            {
              /* If `insert_regs' changes something, the hash code must be
              /* If `insert_regs' changes something, the hash code must be
                 recalculated.  */
                 recalculated.  */
              rehash_using_reg (dest);
              rehash_using_reg (dest);
              sets[i].dest_hash = HASH (dest, GET_MODE (dest));
              sets[i].dest_hash = HASH (dest, GET_MODE (dest));
            }
            }
 
 
        elt = insert (dest, sets[i].src_elt,
        elt = insert (dest, sets[i].src_elt,
                      sets[i].dest_hash, GET_MODE (dest));
                      sets[i].dest_hash, GET_MODE (dest));
 
 
        elt->in_memory = (MEM_P (sets[i].inner_dest)
        elt->in_memory = (MEM_P (sets[i].inner_dest)
                          && !MEM_READONLY_P (sets[i].inner_dest));
                          && !MEM_READONLY_P (sets[i].inner_dest));
 
 
        /* If we have (set (subreg:m1 (reg:m2 foo) 0) (bar:m1)), M1 is no
        /* If we have (set (subreg:m1 (reg:m2 foo) 0) (bar:m1)), M1 is no
           narrower than M2, and both M1 and M2 are the same number of words,
           narrower than M2, and both M1 and M2 are the same number of words,
           we are also doing (set (reg:m2 foo) (subreg:m2 (bar:m1) 0)) so
           we are also doing (set (reg:m2 foo) (subreg:m2 (bar:m1) 0)) so
           make that equivalence as well.
           make that equivalence as well.
 
 
           However, BAR may have equivalences for which gen_lowpart
           However, BAR may have equivalences for which gen_lowpart
           will produce a simpler value than gen_lowpart applied to
           will produce a simpler value than gen_lowpart applied to
           BAR (e.g., if BAR was ZERO_EXTENDed from M2), so we will scan all
           BAR (e.g., if BAR was ZERO_EXTENDed from M2), so we will scan all
           BAR's equivalences.  If we don't get a simplified form, make
           BAR's equivalences.  If we don't get a simplified form, make
           the SUBREG.  It will not be used in an equivalence, but will
           the SUBREG.  It will not be used in an equivalence, but will
           cause two similar assignments to be detected.
           cause two similar assignments to be detected.
 
 
           Note the loop below will find SUBREG_REG (DEST) since we have
           Note the loop below will find SUBREG_REG (DEST) since we have
           already entered SRC and DEST of the SET in the table.  */
           already entered SRC and DEST of the SET in the table.  */
 
 
        if (GET_CODE (dest) == SUBREG
        if (GET_CODE (dest) == SUBREG
            && (((GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))) - 1)
            && (((GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))) - 1)
                 / UNITS_PER_WORD)
                 / UNITS_PER_WORD)
                == (GET_MODE_SIZE (GET_MODE (dest)) - 1) / UNITS_PER_WORD)
                == (GET_MODE_SIZE (GET_MODE (dest)) - 1) / UNITS_PER_WORD)
            && (GET_MODE_SIZE (GET_MODE (dest))
            && (GET_MODE_SIZE (GET_MODE (dest))
                >= GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))))
                >= GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest))))
            && sets[i].src_elt != 0)
            && sets[i].src_elt != 0)
          {
          {
            enum machine_mode new_mode = GET_MODE (SUBREG_REG (dest));
            enum machine_mode new_mode = GET_MODE (SUBREG_REG (dest));
            struct table_elt *elt, *classp = 0;
            struct table_elt *elt, *classp = 0;
 
 
            for (elt = sets[i].src_elt->first_same_value; elt;
            for (elt = sets[i].src_elt->first_same_value; elt;
                 elt = elt->next_same_value)
                 elt = elt->next_same_value)
              {
              {
                rtx new_src = 0;
                rtx new_src = 0;
                unsigned src_hash;
                unsigned src_hash;
                struct table_elt *src_elt;
                struct table_elt *src_elt;
                int byte = 0;
                int byte = 0;
 
 
                /* Ignore invalid entries.  */
                /* Ignore invalid entries.  */
                if (!REG_P (elt->exp)
                if (!REG_P (elt->exp)
                    && ! exp_equiv_p (elt->exp, elt->exp, 1, false))
                    && ! exp_equiv_p (elt->exp, elt->exp, 1, false))
                  continue;
                  continue;
 
 
                /* We may have already been playing subreg games.  If the
                /* We may have already been playing subreg games.  If the
                   mode is already correct for the destination, use it.  */
                   mode is already correct for the destination, use it.  */
                if (GET_MODE (elt->exp) == new_mode)
                if (GET_MODE (elt->exp) == new_mode)
                  new_src = elt->exp;
                  new_src = elt->exp;
                else
                else
                  {
                  {
                    /* Calculate big endian correction for the SUBREG_BYTE.
                    /* Calculate big endian correction for the SUBREG_BYTE.
                       We have already checked that M1 (GET_MODE (dest))
                       We have already checked that M1 (GET_MODE (dest))
                       is not narrower than M2 (new_mode).  */
                       is not narrower than M2 (new_mode).  */
                    if (BYTES_BIG_ENDIAN)
                    if (BYTES_BIG_ENDIAN)
                      byte = (GET_MODE_SIZE (GET_MODE (dest))
                      byte = (GET_MODE_SIZE (GET_MODE (dest))
                              - GET_MODE_SIZE (new_mode));
                              - GET_MODE_SIZE (new_mode));
 
 
                    new_src = simplify_gen_subreg (new_mode, elt->exp,
                    new_src = simplify_gen_subreg (new_mode, elt->exp,
                                                   GET_MODE (dest), byte);
                                                   GET_MODE (dest), byte);
                  }
                  }
 
 
                /* The call to simplify_gen_subreg fails if the value
                /* The call to simplify_gen_subreg fails if the value
                   is VOIDmode, yet we can't do any simplification, e.g.
                   is VOIDmode, yet we can't do any simplification, e.g.
                   for EXPR_LISTs denoting function call results.
                   for EXPR_LISTs denoting function call results.
                   It is invalid to construct a SUBREG with a VOIDmode
                   It is invalid to construct a SUBREG with a VOIDmode
                   SUBREG_REG, hence a zero new_src means we can't do
                   SUBREG_REG, hence a zero new_src means we can't do
                   this substitution.  */
                   this substitution.  */
                if (! new_src)
                if (! new_src)
                  continue;
                  continue;
 
 
                src_hash = HASH (new_src, new_mode);
                src_hash = HASH (new_src, new_mode);
                src_elt = lookup (new_src, src_hash, new_mode);
                src_elt = lookup (new_src, src_hash, new_mode);
 
 
                /* Put the new source in the hash table is if isn't
                /* Put the new source in the hash table is if isn't
                   already.  */
                   already.  */
                if (src_elt == 0)
                if (src_elt == 0)
                  {
                  {
                    if (insert_regs (new_src, classp, 0))
                    if (insert_regs (new_src, classp, 0))
                      {
                      {
                        rehash_using_reg (new_src);
                        rehash_using_reg (new_src);
                        src_hash = HASH (new_src, new_mode);
                        src_hash = HASH (new_src, new_mode);
                      }
                      }
                    src_elt = insert (new_src, classp, src_hash, new_mode);
                    src_elt = insert (new_src, classp, src_hash, new_mode);
                    src_elt->in_memory = elt->in_memory;
                    src_elt->in_memory = elt->in_memory;
                  }
                  }
                else if (classp && classp != src_elt->first_same_value)
                else if (classp && classp != src_elt->first_same_value)
                  /* Show that two things that we've seen before are
                  /* Show that two things that we've seen before are
                     actually the same.  */
                     actually the same.  */
                  merge_equiv_classes (src_elt, classp);
                  merge_equiv_classes (src_elt, classp);
 
 
                classp = src_elt->first_same_value;
                classp = src_elt->first_same_value;
                /* Ignore invalid entries.  */
                /* Ignore invalid entries.  */
                while (classp
                while (classp
                       && !REG_P (classp->exp)
                       && !REG_P (classp->exp)
                       && ! exp_equiv_p (classp->exp, classp->exp, 1, false))
                       && ! exp_equiv_p (classp->exp, classp->exp, 1, false))
                  classp = classp->next_same_value;
                  classp = classp->next_same_value;
              }
              }
          }
          }
      }
      }
 
 
  /* Special handling for (set REG0 REG1) where REG0 is the
  /* Special handling for (set REG0 REG1) where REG0 is the
     "cheapest", cheaper than REG1.  After cse, REG1 will probably not
     "cheapest", cheaper than REG1.  After cse, REG1 will probably not
     be used in the sequel, so (if easily done) change this insn to
     be used in the sequel, so (if easily done) change this insn to
     (set REG1 REG0) and replace REG1 with REG0 in the previous insn
     (set REG1 REG0) and replace REG1 with REG0 in the previous insn
     that computed their value.  Then REG1 will become a dead store
     that computed their value.  Then REG1 will become a dead store
     and won't cloud the situation for later optimizations.
     and won't cloud the situation for later optimizations.
 
 
     Do not make this change if REG1 is a hard register, because it will
     Do not make this change if REG1 is a hard register, because it will
     then be used in the sequel and we may be changing a two-operand insn
     then be used in the sequel and we may be changing a two-operand insn
     into a three-operand insn.
     into a three-operand insn.
 
 
     Also do not do this if we are operating on a copy of INSN.
     Also do not do this if we are operating on a copy of INSN.
 
 
     Also don't do this if INSN ends a libcall; this would cause an unrelated
     Also don't do this if INSN ends a libcall; this would cause an unrelated
     register to be set in the middle of a libcall, and we then get bad code
     register to be set in the middle of a libcall, and we then get bad code
     if the libcall is deleted.  */
     if the libcall is deleted.  */
 
 
  if (n_sets == 1 && sets[0].rtl && REG_P (SET_DEST (sets[0].rtl))
  if (n_sets == 1 && sets[0].rtl && REG_P (SET_DEST (sets[0].rtl))
      && NEXT_INSN (PREV_INSN (insn)) == insn
      && NEXT_INSN (PREV_INSN (insn)) == insn
      && REG_P (SET_SRC (sets[0].rtl))
      && REG_P (SET_SRC (sets[0].rtl))
      && REGNO (SET_SRC (sets[0].rtl)) >= FIRST_PSEUDO_REGISTER
      && REGNO (SET_SRC (sets[0].rtl)) >= FIRST_PSEUDO_REGISTER
      && REGNO_QTY_VALID_P (REGNO (SET_SRC (sets[0].rtl))))
      && REGNO_QTY_VALID_P (REGNO (SET_SRC (sets[0].rtl))))
    {
    {
      int src_q = REG_QTY (REGNO (SET_SRC (sets[0].rtl)));
      int src_q = REG_QTY (REGNO (SET_SRC (sets[0].rtl)));
      struct qty_table_elem *src_ent = &qty_table[src_q];
      struct qty_table_elem *src_ent = &qty_table[src_q];
 
 
      if ((src_ent->first_reg == REGNO (SET_DEST (sets[0].rtl)))
      if ((src_ent->first_reg == REGNO (SET_DEST (sets[0].rtl)))
          && ! find_reg_note (insn, REG_RETVAL, NULL_RTX))
          && ! find_reg_note (insn, REG_RETVAL, NULL_RTX))
        {
        {
          rtx prev = insn;
          rtx prev = insn;
          /* Scan for the previous nonnote insn, but stop at a basic
          /* Scan for the previous nonnote insn, but stop at a basic
             block boundary.  */
             block boundary.  */
          do
          do
            {
            {
              prev = PREV_INSN (prev);
              prev = PREV_INSN (prev);
            }
            }
          while (prev && NOTE_P (prev)
          while (prev && NOTE_P (prev)
                 && NOTE_LINE_NUMBER (prev) != NOTE_INSN_BASIC_BLOCK);
                 && NOTE_LINE_NUMBER (prev) != NOTE_INSN_BASIC_BLOCK);
 
 
          /* Do not swap the registers around if the previous instruction
          /* Do not swap the registers around if the previous instruction
             attaches a REG_EQUIV note to REG1.
             attaches a REG_EQUIV note to REG1.
 
 
             ??? It's not entirely clear whether we can transfer a REG_EQUIV
             ??? It's not entirely clear whether we can transfer a REG_EQUIV
             from the pseudo that originally shadowed an incoming argument
             from the pseudo that originally shadowed an incoming argument
             to another register.  Some uses of REG_EQUIV might rely on it
             to another register.  Some uses of REG_EQUIV might rely on it
             being attached to REG1 rather than REG2.
             being attached to REG1 rather than REG2.
 
 
             This section previously turned the REG_EQUIV into a REG_EQUAL
             This section previously turned the REG_EQUIV into a REG_EQUAL
             note.  We cannot do that because REG_EQUIV may provide an
             note.  We cannot do that because REG_EQUIV may provide an
             uninitialized stack slot when REG_PARM_STACK_SPACE is used.  */
             uninitialized stack slot when REG_PARM_STACK_SPACE is used.  */
 
 
          if (prev != 0 && NONJUMP_INSN_P (prev)
          if (prev != 0 && NONJUMP_INSN_P (prev)
              && GET_CODE (PATTERN (prev)) == SET
              && GET_CODE (PATTERN (prev)) == SET
              && SET_DEST (PATTERN (prev)) == SET_SRC (sets[0].rtl)
              && SET_DEST (PATTERN (prev)) == SET_SRC (sets[0].rtl)
              && ! find_reg_note (prev, REG_EQUIV, NULL_RTX))
              && ! find_reg_note (prev, REG_EQUIV, NULL_RTX))
            {
            {
              rtx dest = SET_DEST (sets[0].rtl);
              rtx dest = SET_DEST (sets[0].rtl);
              rtx src = SET_SRC (sets[0].rtl);
              rtx src = SET_SRC (sets[0].rtl);
              rtx note;
              rtx note;
 
 
              validate_change (prev, &SET_DEST (PATTERN (prev)), dest, 1);
              validate_change (prev, &SET_DEST (PATTERN (prev)), dest, 1);
              validate_change (insn, &SET_DEST (sets[0].rtl), src, 1);
              validate_change (insn, &SET_DEST (sets[0].rtl), src, 1);
              validate_change (insn, &SET_SRC (sets[0].rtl), dest, 1);
              validate_change (insn, &SET_SRC (sets[0].rtl), dest, 1);
              apply_change_group ();
              apply_change_group ();
 
 
              /* If INSN has a REG_EQUAL note, and this note mentions
              /* If INSN has a REG_EQUAL note, and this note mentions
                 REG0, then we must delete it, because the value in
                 REG0, then we must delete it, because the value in
                 REG0 has changed.  If the note's value is REG1, we must
                 REG0 has changed.  If the note's value is REG1, we must
                 also delete it because that is now this insn's dest.  */
                 also delete it because that is now this insn's dest.  */
              note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
              note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
              if (note != 0
              if (note != 0
                  && (reg_mentioned_p (dest, XEXP (note, 0))
                  && (reg_mentioned_p (dest, XEXP (note, 0))
                      || rtx_equal_p (src, XEXP (note, 0))))
                      || rtx_equal_p (src, XEXP (note, 0))))
                remove_note (insn, note);
                remove_note (insn, note);
            }
            }
        }
        }
    }
    }
 
 
  /* If this is a conditional jump insn, record any known equivalences due to
  /* If this is a conditional jump insn, record any known equivalences due to
     the condition being tested.  */
     the condition being tested.  */
 
 
  if (JUMP_P (insn)
  if (JUMP_P (insn)
      && n_sets == 1 && GET_CODE (x) == SET
      && n_sets == 1 && GET_CODE (x) == SET
      && GET_CODE (SET_SRC (x)) == IF_THEN_ELSE)
      && GET_CODE (SET_SRC (x)) == IF_THEN_ELSE)
    record_jump_equiv (insn, 0);
    record_jump_equiv (insn, 0);
 
 
#ifdef HAVE_cc0
#ifdef HAVE_cc0
  /* If the previous insn set CC0 and this insn no longer references CC0,
  /* If the previous insn set CC0 and this insn no longer references CC0,
     delete the previous insn.  Here we use the fact that nothing expects CC0
     delete the previous insn.  Here we use the fact that nothing expects CC0
     to be valid over an insn, which is true until the final pass.  */
     to be valid over an insn, which is true until the final pass.  */
  if (prev_insn && NONJUMP_INSN_P (prev_insn)
  if (prev_insn && NONJUMP_INSN_P (prev_insn)
      && (tem = single_set (prev_insn)) != 0
      && (tem = single_set (prev_insn)) != 0
      && SET_DEST (tem) == cc0_rtx
      && SET_DEST (tem) == cc0_rtx
      && ! reg_mentioned_p (cc0_rtx, x))
      && ! reg_mentioned_p (cc0_rtx, x))
    delete_insn (prev_insn);
    delete_insn (prev_insn);
 
 
  prev_insn_cc0 = this_insn_cc0;
  prev_insn_cc0 = this_insn_cc0;
  prev_insn_cc0_mode = this_insn_cc0_mode;
  prev_insn_cc0_mode = this_insn_cc0_mode;
  prev_insn = insn;
  prev_insn = insn;
#endif
#endif
}
}


/* Remove from the hash table all expressions that reference memory.  */
/* Remove from the hash table all expressions that reference memory.  */
 
 
static void
static void
invalidate_memory (void)
invalidate_memory (void)
{
{
  int i;
  int i;
  struct table_elt *p, *next;
  struct table_elt *p, *next;
 
 
  for (i = 0; i < HASH_SIZE; i++)
  for (i = 0; i < HASH_SIZE; i++)
    for (p = table[i]; p; p = next)
    for (p = table[i]; p; p = next)
      {
      {
        next = p->next_same_hash;
        next = p->next_same_hash;
        if (p->in_memory)
        if (p->in_memory)
          remove_from_table (p, i);
          remove_from_table (p, i);
      }
      }
}
}
 
 
/* If ADDR is an address that implicitly affects the stack pointer, return
/* If ADDR is an address that implicitly affects the stack pointer, return
   1 and update the register tables to show the effect.  Else, return 0.  */
   1 and update the register tables to show the effect.  Else, return 0.  */
 
 
static int
static int
addr_affects_sp_p (rtx addr)
addr_affects_sp_p (rtx addr)
{
{
  if (GET_RTX_CLASS (GET_CODE (addr)) == RTX_AUTOINC
  if (GET_RTX_CLASS (GET_CODE (addr)) == RTX_AUTOINC
      && REG_P (XEXP (addr, 0))
      && REG_P (XEXP (addr, 0))
      && REGNO (XEXP (addr, 0)) == STACK_POINTER_REGNUM)
      && REGNO (XEXP (addr, 0)) == STACK_POINTER_REGNUM)
    {
    {
      if (REG_TICK (STACK_POINTER_REGNUM) >= 0)
      if (REG_TICK (STACK_POINTER_REGNUM) >= 0)
        {
        {
          REG_TICK (STACK_POINTER_REGNUM)++;
          REG_TICK (STACK_POINTER_REGNUM)++;
          /* Is it possible to use a subreg of SP?  */
          /* Is it possible to use a subreg of SP?  */
          SUBREG_TICKED (STACK_POINTER_REGNUM) = -1;
          SUBREG_TICKED (STACK_POINTER_REGNUM) = -1;
        }
        }
 
 
      /* This should be *very* rare.  */
      /* This should be *very* rare.  */
      if (TEST_HARD_REG_BIT (hard_regs_in_table, STACK_POINTER_REGNUM))
      if (TEST_HARD_REG_BIT (hard_regs_in_table, STACK_POINTER_REGNUM))
        invalidate (stack_pointer_rtx, VOIDmode);
        invalidate (stack_pointer_rtx, VOIDmode);
 
 
      return 1;
      return 1;
    }
    }
 
 
  return 0;
  return 0;
}
}
 
 
/* Perform invalidation on the basis of everything about an insn
/* Perform invalidation on the basis of everything about an insn
   except for invalidating the actual places that are SET in it.
   except for invalidating the actual places that are SET in it.
   This includes the places CLOBBERed, and anything that might
   This includes the places CLOBBERed, and anything that might
   alias with something that is SET or CLOBBERed.
   alias with something that is SET or CLOBBERed.
 
 
   X is the pattern of the insn.  */
   X is the pattern of the insn.  */
 
 
static void
static void
invalidate_from_clobbers (rtx x)
invalidate_from_clobbers (rtx x)
{
{
  if (GET_CODE (x) == CLOBBER)
  if (GET_CODE (x) == CLOBBER)
    {
    {
      rtx ref = XEXP (x, 0);
      rtx ref = XEXP (x, 0);
      if (ref)
      if (ref)
        {
        {
          if (REG_P (ref) || GET_CODE (ref) == SUBREG
          if (REG_P (ref) || GET_CODE (ref) == SUBREG
              || MEM_P (ref))
              || MEM_P (ref))
            invalidate (ref, VOIDmode);
            invalidate (ref, VOIDmode);
          else if (GET_CODE (ref) == STRICT_LOW_PART
          else if (GET_CODE (ref) == STRICT_LOW_PART
                   || GET_CODE (ref) == ZERO_EXTRACT)
                   || GET_CODE (ref) == ZERO_EXTRACT)
            invalidate (XEXP (ref, 0), GET_MODE (ref));
            invalidate (XEXP (ref, 0), GET_MODE (ref));
        }
        }
    }
    }
  else if (GET_CODE (x) == PARALLEL)
  else if (GET_CODE (x) == PARALLEL)
    {
    {
      int i;
      int i;
      for (i = XVECLEN (x, 0) - 1; i >= 0; i--)
      for (i = XVECLEN (x, 0) - 1; i >= 0; i--)
        {
        {
          rtx y = XVECEXP (x, 0, i);
          rtx y = XVECEXP (x, 0, i);
          if (GET_CODE (y) == CLOBBER)
          if (GET_CODE (y) == CLOBBER)
            {
            {
              rtx ref = XEXP (y, 0);
              rtx ref = XEXP (y, 0);
              if (REG_P (ref) || GET_CODE (ref) == SUBREG
              if (REG_P (ref) || GET_CODE (ref) == SUBREG
                  || MEM_P (ref))
                  || MEM_P (ref))
                invalidate (ref, VOIDmode);
                invalidate (ref, VOIDmode);
              else if (GET_CODE (ref) == STRICT_LOW_PART
              else if (GET_CODE (ref) == STRICT_LOW_PART
                       || GET_CODE (ref) == ZERO_EXTRACT)
                       || GET_CODE (ref) == ZERO_EXTRACT)
                invalidate (XEXP (ref, 0), GET_MODE (ref));
                invalidate (XEXP (ref, 0), GET_MODE (ref));
            }
            }
        }
        }
    }
    }
}
}


/* Process X, part of the REG_NOTES of an insn.  Look at any REG_EQUAL notes
/* Process X, part of the REG_NOTES of an insn.  Look at any REG_EQUAL notes
   and replace any registers in them with either an equivalent constant
   and replace any registers in them with either an equivalent constant
   or the canonical form of the register.  If we are inside an address,
   or the canonical form of the register.  If we are inside an address,
   only do this if the address remains valid.
   only do this if the address remains valid.
 
 
   OBJECT is 0 except when within a MEM in which case it is the MEM.
   OBJECT is 0 except when within a MEM in which case it is the MEM.
 
 
   Return the replacement for X.  */
   Return the replacement for X.  */
 
 
static rtx
static rtx
cse_process_notes (rtx x, rtx object)
cse_process_notes (rtx x, rtx object)
{
{
  enum rtx_code code = GET_CODE (x);
  enum rtx_code code = GET_CODE (x);
  const char *fmt = GET_RTX_FORMAT (code);
  const char *fmt = GET_RTX_FORMAT (code);
  int i;
  int i;
 
 
  switch (code)
  switch (code)
    {
    {
    case CONST_INT:
    case CONST_INT:
    case CONST:
    case CONST:
    case SYMBOL_REF:
    case SYMBOL_REF:
    case LABEL_REF:
    case LABEL_REF:
    case CONST_DOUBLE:
    case CONST_DOUBLE:
    case CONST_VECTOR:
    case CONST_VECTOR:
    case PC:
    case PC:
    case CC0:
    case CC0:
    case LO_SUM:
    case LO_SUM:
      return x;
      return x;
 
 
    case MEM:
    case MEM:
      validate_change (x, &XEXP (x, 0),
      validate_change (x, &XEXP (x, 0),
                       cse_process_notes (XEXP (x, 0), x), 0);
                       cse_process_notes (XEXP (x, 0), x), 0);
      return x;
      return x;
 
 
    case EXPR_LIST:
    case EXPR_LIST:
    case INSN_LIST:
    case INSN_LIST:
      if (REG_NOTE_KIND (x) == REG_EQUAL)
      if (REG_NOTE_KIND (x) == REG_EQUAL)
        XEXP (x, 0) = cse_process_notes (XEXP (x, 0), NULL_RTX);
        XEXP (x, 0) = cse_process_notes (XEXP (x, 0), NULL_RTX);
      if (XEXP (x, 1))
      if (XEXP (x, 1))
        XEXP (x, 1) = cse_process_notes (XEXP (x, 1), NULL_RTX);
        XEXP (x, 1) = cse_process_notes (XEXP (x, 1), NULL_RTX);
      return x;
      return x;
 
 
    case SIGN_EXTEND:
    case SIGN_EXTEND:
    case ZERO_EXTEND:
    case ZERO_EXTEND:
    case SUBREG:
    case SUBREG:
      {
      {
        rtx new = cse_process_notes (XEXP (x, 0), object);
        rtx new = cse_process_notes (XEXP (x, 0), object);
        /* We don't substitute VOIDmode constants into these rtx,
        /* We don't substitute VOIDmode constants into these rtx,
           since they would impede folding.  */
           since they would impede folding.  */
        if (GET_MODE (new) != VOIDmode)
        if (GET_MODE (new) != VOIDmode)
          validate_change (object, &XEXP (x, 0), new, 0);
          validate_change (object, &XEXP (x, 0), new, 0);
        return x;
        return x;
      }
      }
 
 
    case REG:
    case REG:
      i = REG_QTY (REGNO (x));
      i = REG_QTY (REGNO (x));
 
 
      /* Return a constant or a constant register.  */
      /* Return a constant or a constant register.  */
      if (REGNO_QTY_VALID_P (REGNO (x)))
      if (REGNO_QTY_VALID_P (REGNO (x)))
        {
        {
          struct qty_table_elem *ent = &qty_table[i];
          struct qty_table_elem *ent = &qty_table[i];
 
 
          if (ent->const_rtx != NULL_RTX
          if (ent->const_rtx != NULL_RTX
              && (CONSTANT_P (ent->const_rtx)
              && (CONSTANT_P (ent->const_rtx)
                  || REG_P (ent->const_rtx)))
                  || REG_P (ent->const_rtx)))
            {
            {
              rtx new = gen_lowpart (GET_MODE (x), ent->const_rtx);
              rtx new = gen_lowpart (GET_MODE (x), ent->const_rtx);
              if (new)
              if (new)
                return new;
                return new;
            }
            }
        }
        }
 
 
      /* Otherwise, canonicalize this register.  */
      /* Otherwise, canonicalize this register.  */
      return canon_reg (x, NULL_RTX);
      return canon_reg (x, NULL_RTX);
 
 
    default:
    default:
      break;
      break;
    }
    }
 
 
  for (i = 0; i < GET_RTX_LENGTH (code); i++)
  for (i = 0; i < GET_RTX_LENGTH (code); i++)
    if (fmt[i] == 'e')
    if (fmt[i] == 'e')
      validate_change (object, &XEXP (x, i),
      validate_change (object, &XEXP (x, i),
                       cse_process_notes (XEXP (x, i), object), 0);
                       cse_process_notes (XEXP (x, i), object), 0);
 
 
  return x;
  return x;
}
}


/* Process one SET of an insn that was skipped.  We ignore CLOBBERs
/* Process one SET of an insn that was skipped.  We ignore CLOBBERs
   since they are done elsewhere.  This function is called via note_stores.  */
   since they are done elsewhere.  This function is called via note_stores.  */
 
 
static void
static void
invalidate_skipped_set (rtx dest, rtx set, void *data ATTRIBUTE_UNUSED)
invalidate_skipped_set (rtx dest, rtx set, void *data ATTRIBUTE_UNUSED)
{
{
  enum rtx_code code = GET_CODE (dest);
  enum rtx_code code = GET_CODE (dest);
 
 
  if (code == MEM
  if (code == MEM
      && ! addr_affects_sp_p (dest)     /* If this is not a stack push ...  */
      && ! addr_affects_sp_p (dest)     /* If this is not a stack push ...  */
      /* There are times when an address can appear varying and be a PLUS
      /* There are times when an address can appear varying and be a PLUS
         during this scan when it would be a fixed address were we to know
         during this scan when it would be a fixed address were we to know
         the proper equivalences.  So invalidate all memory if there is
         the proper equivalences.  So invalidate all memory if there is
         a BLKmode or nonscalar memory reference or a reference to a
         a BLKmode or nonscalar memory reference or a reference to a
         variable address.  */
         variable address.  */
      && (MEM_IN_STRUCT_P (dest) || GET_MODE (dest) == BLKmode
      && (MEM_IN_STRUCT_P (dest) || GET_MODE (dest) == BLKmode
          || cse_rtx_varies_p (XEXP (dest, 0), 0)))
          || cse_rtx_varies_p (XEXP (dest, 0), 0)))
    {
    {
      invalidate_memory ();
      invalidate_memory ();
      return;
      return;
    }
    }
 
 
  if (GET_CODE (set) == CLOBBER
  if (GET_CODE (set) == CLOBBER
      || CC0_P (dest)
      || CC0_P (dest)
      || dest == pc_rtx)
      || dest == pc_rtx)
    return;
    return;
 
 
  if (code == STRICT_LOW_PART || code == ZERO_EXTRACT)
  if (code == STRICT_LOW_PART || code == ZERO_EXTRACT)
    invalidate (XEXP (dest, 0), GET_MODE (dest));
    invalidate (XEXP (dest, 0), GET_MODE (dest));
  else if (code == REG || code == SUBREG || code == MEM)
  else if (code == REG || code == SUBREG || code == MEM)
    invalidate (dest, VOIDmode);
    invalidate (dest, VOIDmode);
}
}
 
 
/* Invalidate all insns from START up to the end of the function or the
/* Invalidate all insns from START up to the end of the function or the
   next label.  This called when we wish to CSE around a block that is
   next label.  This called when we wish to CSE around a block that is
   conditionally executed.  */
   conditionally executed.  */
 
 
static void
static void
invalidate_skipped_block (rtx start)
invalidate_skipped_block (rtx start)
{
{
  rtx insn;
  rtx insn;
 
 
  for (insn = start; insn && !LABEL_P (insn);
  for (insn = start; insn && !LABEL_P (insn);
       insn = NEXT_INSN (insn))
       insn = NEXT_INSN (insn))
    {
    {
      if (! INSN_P (insn))
      if (! INSN_P (insn))
        continue;
        continue;
 
 
      if (CALL_P (insn))
      if (CALL_P (insn))
        {
        {
          if (! CONST_OR_PURE_CALL_P (insn))
          if (! CONST_OR_PURE_CALL_P (insn))
            invalidate_memory ();
            invalidate_memory ();
          invalidate_for_call ();
          invalidate_for_call ();
        }
        }
 
 
      invalidate_from_clobbers (PATTERN (insn));
      invalidate_from_clobbers (PATTERN (insn));
      note_stores (PATTERN (insn), invalidate_skipped_set, NULL);
      note_stores (PATTERN (insn), invalidate_skipped_set, NULL);
    }
    }
}
}


/* Find the end of INSN's basic block and return its range,
/* Find the end of INSN's basic block and return its range,
   the total number of SETs in all the insns of the block, the last insn of the
   the total number of SETs in all the insns of the block, the last insn of the
   block, and the branch path.
   block, and the branch path.
 
 
   The branch path indicates which branches should be followed.  If a nonzero
   The branch path indicates which branches should be followed.  If a nonzero
   path size is specified, the block should be rescanned and a different set
   path size is specified, the block should be rescanned and a different set
   of branches will be taken.  The branch path is only used if
   of branches will be taken.  The branch path is only used if
   FLAG_CSE_FOLLOW_JUMPS or FLAG_CSE_SKIP_BLOCKS is nonzero.
   FLAG_CSE_FOLLOW_JUMPS or FLAG_CSE_SKIP_BLOCKS is nonzero.
 
 
   DATA is a pointer to a struct cse_basic_block_data, defined below, that is
   DATA is a pointer to a struct cse_basic_block_data, defined below, that is
   used to describe the block.  It is filled in with the information about
   used to describe the block.  It is filled in with the information about
   the current block.  The incoming structure's branch path, if any, is used
   the current block.  The incoming structure's branch path, if any, is used
   to construct the output branch path.  */
   to construct the output branch path.  */
 
 
static void
static void
cse_end_of_basic_block (rtx insn, struct cse_basic_block_data *data,
cse_end_of_basic_block (rtx insn, struct cse_basic_block_data *data,
                        int follow_jumps, int skip_blocks)
                        int follow_jumps, int skip_blocks)
{
{
  rtx p = insn, q;
  rtx p = insn, q;
  int nsets = 0;
  int nsets = 0;
  int low_cuid = INSN_CUID (insn), high_cuid = INSN_CUID (insn);
  int low_cuid = INSN_CUID (insn), high_cuid = INSN_CUID (insn);
  rtx next = INSN_P (insn) ? insn : next_real_insn (insn);
  rtx next = INSN_P (insn) ? insn : next_real_insn (insn);
  int path_size = data->path_size;
  int path_size = data->path_size;
  int path_entry = 0;
  int path_entry = 0;
  int i;
  int i;
 
 
  /* Update the previous branch path, if any.  If the last branch was
  /* Update the previous branch path, if any.  If the last branch was
     previously PATH_TAKEN, mark it PATH_NOT_TAKEN.
     previously PATH_TAKEN, mark it PATH_NOT_TAKEN.
     If it was previously PATH_NOT_TAKEN,
     If it was previously PATH_NOT_TAKEN,
     shorten the path by one and look at the previous branch.  We know that
     shorten the path by one and look at the previous branch.  We know that
     at least one branch must have been taken if PATH_SIZE is nonzero.  */
     at least one branch must have been taken if PATH_SIZE is nonzero.  */
  while (path_size > 0)
  while (path_size > 0)
    {
    {
      if (data->path[path_size - 1].status != PATH_NOT_TAKEN)
      if (data->path[path_size - 1].status != PATH_NOT_TAKEN)
        {
        {
          data->path[path_size - 1].status = PATH_NOT_TAKEN;
          data->path[path_size - 1].status = PATH_NOT_TAKEN;
          break;
          break;
        }
        }
      else
      else
        path_size--;
        path_size--;
    }
    }
 
 
  /* If the first instruction is marked with QImode, that means we've
  /* If the first instruction is marked with QImode, that means we've
     already processed this block.  Our caller will look at DATA->LAST
     already processed this block.  Our caller will look at DATA->LAST
     to figure out where to go next.  We want to return the next block
     to figure out where to go next.  We want to return the next block
     in the instruction stream, not some branched-to block somewhere
     in the instruction stream, not some branched-to block somewhere
     else.  We accomplish this by pretending our called forbid us to
     else.  We accomplish this by pretending our called forbid us to
     follow jumps, or skip blocks.  */
     follow jumps, or skip blocks.  */
  if (GET_MODE (insn) == QImode)
  if (GET_MODE (insn) == QImode)
    follow_jumps = skip_blocks = 0;
    follow_jumps = skip_blocks = 0;
 
 
  /* Scan to end of this basic block.  */
  /* Scan to end of this basic block.  */
  while (p && !LABEL_P (p))
  while (p && !LABEL_P (p))
    {
    {
      /* Don't cse over a call to setjmp; on some machines (eg VAX)
      /* Don't cse over a call to setjmp; on some machines (eg VAX)
         the regs restored by the longjmp come from
         the regs restored by the longjmp come from
         a later time than the setjmp.  */
         a later time than the setjmp.  */
      if (PREV_INSN (p) && CALL_P (PREV_INSN (p))
      if (PREV_INSN (p) && CALL_P (PREV_INSN (p))
          && find_reg_note (PREV_INSN (p), REG_SETJMP, NULL))
          && find_reg_note (PREV_INSN (p), REG_SETJMP, NULL))
        break;
        break;
 
 
      /* A PARALLEL can have lots of SETs in it,
      /* A PARALLEL can have lots of SETs in it,
         especially if it is really an ASM_OPERANDS.  */
         especially if it is really an ASM_OPERANDS.  */
      if (INSN_P (p) && GET_CODE (PATTERN (p)) == PARALLEL)
      if (INSN_P (p) && GET_CODE (PATTERN (p)) == PARALLEL)
        nsets += XVECLEN (PATTERN (p), 0);
        nsets += XVECLEN (PATTERN (p), 0);
      else if (!NOTE_P (p))
      else if (!NOTE_P (p))
        nsets += 1;
        nsets += 1;
 
 
      /* Ignore insns made by CSE; they cannot affect the boundaries of
      /* Ignore insns made by CSE; they cannot affect the boundaries of
         the basic block.  */
         the basic block.  */
 
 
      if (INSN_UID (p) <= max_uid && INSN_CUID (p) > high_cuid)
      if (INSN_UID (p) <= max_uid && INSN_CUID (p) > high_cuid)
        high_cuid = INSN_CUID (p);
        high_cuid = INSN_CUID (p);
      if (INSN_UID (p) <= max_uid && INSN_CUID (p) < low_cuid)
      if (INSN_UID (p) <= max_uid && INSN_CUID (p) < low_cuid)
        low_cuid = INSN_CUID (p);
        low_cuid = INSN_CUID (p);
 
 
      /* See if this insn is in our branch path.  If it is and we are to
      /* See if this insn is in our branch path.  If it is and we are to
         take it, do so.  */
         take it, do so.  */
      if (path_entry < path_size && data->path[path_entry].branch == p)
      if (path_entry < path_size && data->path[path_entry].branch == p)
        {
        {
          if (data->path[path_entry].status != PATH_NOT_TAKEN)
          if (data->path[path_entry].status != PATH_NOT_TAKEN)
            p = JUMP_LABEL (p);
            p = JUMP_LABEL (p);
 
 
          /* Point to next entry in path, if any.  */
          /* Point to next entry in path, if any.  */
          path_entry++;
          path_entry++;
        }
        }
 
 
      /* If this is a conditional jump, we can follow it if -fcse-follow-jumps
      /* If this is a conditional jump, we can follow it if -fcse-follow-jumps
         was specified, we haven't reached our maximum path length, there are
         was specified, we haven't reached our maximum path length, there are
         insns following the target of the jump, this is the only use of the
         insns following the target of the jump, this is the only use of the
         jump label, and the target label is preceded by a BARRIER.
         jump label, and the target label is preceded by a BARRIER.
 
 
         Alternatively, we can follow the jump if it branches around a
         Alternatively, we can follow the jump if it branches around a
         block of code and there are no other branches into the block.
         block of code and there are no other branches into the block.
         In this case invalidate_skipped_block will be called to invalidate any
         In this case invalidate_skipped_block will be called to invalidate any
         registers set in the block when following the jump.  */
         registers set in the block when following the jump.  */
 
 
      else if ((follow_jumps || skip_blocks) && path_size < PARAM_VALUE (PARAM_MAX_CSE_PATH_LENGTH) - 1
      else if ((follow_jumps || skip_blocks) && path_size < PARAM_VALUE (PARAM_MAX_CSE_PATH_LENGTH) - 1
               && JUMP_P (p)
               && JUMP_P (p)
               && GET_CODE (PATTERN (p)) == SET
               && GET_CODE (PATTERN (p)) == SET
               && GET_CODE (SET_SRC (PATTERN (p))) == IF_THEN_ELSE
               && GET_CODE (SET_SRC (PATTERN (p))) == IF_THEN_ELSE
               && JUMP_LABEL (p) != 0
               && JUMP_LABEL (p) != 0
               && LABEL_NUSES (JUMP_LABEL (p)) == 1
               && LABEL_NUSES (JUMP_LABEL (p)) == 1
               && NEXT_INSN (JUMP_LABEL (p)) != 0)
               && NEXT_INSN (JUMP_LABEL (p)) != 0)
        {
        {
          for (q = PREV_INSN (JUMP_LABEL (p)); q; q = PREV_INSN (q))
          for (q = PREV_INSN (JUMP_LABEL (p)); q; q = PREV_INSN (q))
            if ((!NOTE_P (q)
            if ((!NOTE_P (q)
                 || (PREV_INSN (q) && CALL_P (PREV_INSN (q))
                 || (PREV_INSN (q) && CALL_P (PREV_INSN (q))
                     && find_reg_note (PREV_INSN (q), REG_SETJMP, NULL)))
                     && find_reg_note (PREV_INSN (q), REG_SETJMP, NULL)))
                && (!LABEL_P (q) || LABEL_NUSES (q) != 0))
                && (!LABEL_P (q) || LABEL_NUSES (q) != 0))
              break;
              break;
 
 
          /* If we ran into a BARRIER, this code is an extension of the
          /* If we ran into a BARRIER, this code is an extension of the
             basic block when the branch is taken.  */
             basic block when the branch is taken.  */
          if (follow_jumps && q != 0 && BARRIER_P (q))
          if (follow_jumps && q != 0 && BARRIER_P (q))
            {
            {
              /* Don't allow ourself to keep walking around an
              /* Don't allow ourself to keep walking around an
                 always-executed loop.  */
                 always-executed loop.  */
              if (next_real_insn (q) == next)
              if (next_real_insn (q) == next)
                {
                {
                  p = NEXT_INSN (p);
                  p = NEXT_INSN (p);
                  continue;
                  continue;
                }
                }
 
 
              /* Similarly, don't put a branch in our path more than once.  */
              /* Similarly, don't put a branch in our path more than once.  */
              for (i = 0; i < path_entry; i++)
              for (i = 0; i < path_entry; i++)
                if (data->path[i].branch == p)
                if (data->path[i].branch == p)
                  break;
                  break;
 
 
              if (i != path_entry)
              if (i != path_entry)
                break;
                break;
 
 
              data->path[path_entry].branch = p;
              data->path[path_entry].branch = p;
              data->path[path_entry++].status = PATH_TAKEN;
              data->path[path_entry++].status = PATH_TAKEN;
 
 
              /* This branch now ends our path.  It was possible that we
              /* This branch now ends our path.  It was possible that we
                 didn't see this branch the last time around (when the
                 didn't see this branch the last time around (when the
                 insn in front of the target was a JUMP_INSN that was
                 insn in front of the target was a JUMP_INSN that was
                 turned into a no-op).  */
                 turned into a no-op).  */
              path_size = path_entry;
              path_size = path_entry;
 
 
              p = JUMP_LABEL (p);
              p = JUMP_LABEL (p);
              /* Mark block so we won't scan it again later.  */
              /* Mark block so we won't scan it again later.  */
              PUT_MODE (NEXT_INSN (p), QImode);
              PUT_MODE (NEXT_INSN (p), QImode);
            }
            }
          /* Detect a branch around a block of code.  */
          /* Detect a branch around a block of code.  */
          else if (skip_blocks && q != 0 && !LABEL_P (q))
          else if (skip_blocks && q != 0 && !LABEL_P (q))
            {
            {
              rtx tmp;
              rtx tmp;
 
 
              if (next_real_insn (q) == next)
              if (next_real_insn (q) == next)
                {
                {
                  p = NEXT_INSN (p);
                  p = NEXT_INSN (p);
                  continue;
                  continue;
                }
                }
 
 
              for (i = 0; i < path_entry; i++)
              for (i = 0; i < path_entry; i++)
                if (data->path[i].branch == p)
                if (data->path[i].branch == p)
                  break;
                  break;
 
 
              if (i != path_entry)
              if (i != path_entry)
                break;
                break;
 
 
              /* This is no_labels_between_p (p, q) with an added check for
              /* This is no_labels_between_p (p, q) with an added check for
                 reaching the end of a function (in case Q precedes P).  */
                 reaching the end of a function (in case Q precedes P).  */
              for (tmp = NEXT_INSN (p); tmp && tmp != q; tmp = NEXT_INSN (tmp))
              for (tmp = NEXT_INSN (p); tmp && tmp != q; tmp = NEXT_INSN (tmp))
                if (LABEL_P (tmp))
                if (LABEL_P (tmp))
                  break;
                  break;
 
 
              if (tmp == q)
              if (tmp == q)
                {
                {
                  data->path[path_entry].branch = p;
                  data->path[path_entry].branch = p;
                  data->path[path_entry++].status = PATH_AROUND;
                  data->path[path_entry++].status = PATH_AROUND;
 
 
                  path_size = path_entry;
                  path_size = path_entry;
 
 
                  p = JUMP_LABEL (p);
                  p = JUMP_LABEL (p);
                  /* Mark block so we won't scan it again later.  */
                  /* Mark block so we won't scan it again later.  */
                  PUT_MODE (NEXT_INSN (p), QImode);
                  PUT_MODE (NEXT_INSN (p), QImode);
                }
                }
            }
            }
        }
        }
      p = NEXT_INSN (p);
      p = NEXT_INSN (p);
    }
    }
 
 
  data->low_cuid = low_cuid;
  data->low_cuid = low_cuid;
  data->high_cuid = high_cuid;
  data->high_cuid = high_cuid;
  data->nsets = nsets;
  data->nsets = nsets;
  data->last = p;
  data->last = p;
 
 
  /* If all jumps in the path are not taken, set our path length to zero
  /* If all jumps in the path are not taken, set our path length to zero
     so a rescan won't be done.  */
     so a rescan won't be done.  */
  for (i = path_size - 1; i >= 0; i--)
  for (i = path_size - 1; i >= 0; i--)
    if (data->path[i].status != PATH_NOT_TAKEN)
    if (data->path[i].status != PATH_NOT_TAKEN)
      break;
      break;
 
 
  if (i == -1)
  if (i == -1)
    data->path_size = 0;
    data->path_size = 0;
  else
  else
    data->path_size = path_size;
    data->path_size = path_size;
 
 
  /* End the current branch path.  */
  /* End the current branch path.  */
  data->path[path_size].branch = 0;
  data->path[path_size].branch = 0;
}
}


/* Perform cse on the instructions of a function.
/* Perform cse on the instructions of a function.
   F is the first instruction.
   F is the first instruction.
   NREGS is one plus the highest pseudo-reg number used in the instruction.
   NREGS is one plus the highest pseudo-reg number used in the instruction.
 
 
   Returns 1 if jump_optimize should be redone due to simplifications
   Returns 1 if jump_optimize should be redone due to simplifications
   in conditional jump instructions.  */
   in conditional jump instructions.  */
 
 
int
int
cse_main (rtx f, int nregs)
cse_main (rtx f, int nregs)
{
{
  struct cse_basic_block_data val;
  struct cse_basic_block_data val;
  rtx insn = f;
  rtx insn = f;
  int i;
  int i;
 
 
  init_cse_reg_info (nregs);
  init_cse_reg_info (nregs);
 
 
  val.path = XNEWVEC (struct branch_path, PARAM_VALUE (PARAM_MAX_CSE_PATH_LENGTH));
  val.path = XNEWVEC (struct branch_path, PARAM_VALUE (PARAM_MAX_CSE_PATH_LENGTH));
 
 
  cse_jumps_altered = 0;
  cse_jumps_altered = 0;
  recorded_label_ref = 0;
  recorded_label_ref = 0;
  constant_pool_entries_cost = 0;
  constant_pool_entries_cost = 0;
  constant_pool_entries_regcost = 0;
  constant_pool_entries_regcost = 0;
  val.path_size = 0;
  val.path_size = 0;
  rtl_hooks = cse_rtl_hooks;
  rtl_hooks = cse_rtl_hooks;
 
 
  init_recog ();
  init_recog ();
  init_alias_analysis ();
  init_alias_analysis ();
 
 
  reg_eqv_table = XNEWVEC (struct reg_eqv_elem, nregs);
  reg_eqv_table = XNEWVEC (struct reg_eqv_elem, nregs);
 
 
  /* Find the largest uid.  */
  /* Find the largest uid.  */
 
 
  max_uid = get_max_uid ();
  max_uid = get_max_uid ();
  uid_cuid = XCNEWVEC (int, max_uid + 1);
  uid_cuid = XCNEWVEC (int, max_uid + 1);
 
 
  /* Compute the mapping from uids to cuids.
  /* Compute the mapping from uids to cuids.
     CUIDs are numbers assigned to insns, like uids,
     CUIDs are numbers assigned to insns, like uids,
     except that cuids increase monotonically through the code.
     except that cuids increase monotonically through the code.
     Don't assign cuids to line-number NOTEs, so that the distance in cuids
     Don't assign cuids to line-number NOTEs, so that the distance in cuids
     between two insns is not affected by -g.  */
     between two insns is not affected by -g.  */
 
 
  for (insn = f, i = 0; insn; insn = NEXT_INSN (insn))
  for (insn = f, i = 0; insn; insn = NEXT_INSN (insn))
    {
    {
      if (!NOTE_P (insn)
      if (!NOTE_P (insn)
          || NOTE_LINE_NUMBER (insn) < 0)
          || NOTE_LINE_NUMBER (insn) < 0)
        INSN_CUID (insn) = ++i;
        INSN_CUID (insn) = ++i;
      else
      else
        /* Give a line number note the same cuid as preceding insn.  */
        /* Give a line number note the same cuid as preceding insn.  */
        INSN_CUID (insn) = i;
        INSN_CUID (insn) = i;
    }
    }
 
 
  /* Loop over basic blocks.
  /* Loop over basic blocks.
     Compute the maximum number of qty's needed for each basic block
     Compute the maximum number of qty's needed for each basic block
     (which is 2 for each SET).  */
     (which is 2 for each SET).  */
  insn = f;
  insn = f;
  while (insn)
  while (insn)
    {
    {
      cse_altered = 0;
      cse_altered = 0;
      cse_end_of_basic_block (insn, &val, flag_cse_follow_jumps,
      cse_end_of_basic_block (insn, &val, flag_cse_follow_jumps,
                              flag_cse_skip_blocks);
                              flag_cse_skip_blocks);
 
 
      /* If this basic block was already processed or has no sets, skip it.  */
      /* If this basic block was already processed or has no sets, skip it.  */
      if (val.nsets == 0 || GET_MODE (insn) == QImode)
      if (val.nsets == 0 || GET_MODE (insn) == QImode)
        {
        {
          PUT_MODE (insn, VOIDmode);
          PUT_MODE (insn, VOIDmode);
          insn = (val.last ? NEXT_INSN (val.last) : 0);
          insn = (val.last ? NEXT_INSN (val.last) : 0);
          val.path_size = 0;
          val.path_size = 0;
          continue;
          continue;
        }
        }
 
 
      cse_basic_block_start = val.low_cuid;
      cse_basic_block_start = val.low_cuid;
      cse_basic_block_end = val.high_cuid;
      cse_basic_block_end = val.high_cuid;
      max_qty = val.nsets * 2;
      max_qty = val.nsets * 2;
 
 
      if (dump_file)
      if (dump_file)
        fprintf (dump_file, ";; Processing block from %d to %d, %d sets.\n",
        fprintf (dump_file, ";; Processing block from %d to %d, %d sets.\n",
                 INSN_UID (insn), val.last ? INSN_UID (val.last) : 0,
                 INSN_UID (insn), val.last ? INSN_UID (val.last) : 0,
                 val.nsets);
                 val.nsets);
 
 
      /* Make MAX_QTY bigger to give us room to optimize
      /* Make MAX_QTY bigger to give us room to optimize
         past the end of this basic block, if that should prove useful.  */
         past the end of this basic block, if that should prove useful.  */
      if (max_qty < 500)
      if (max_qty < 500)
        max_qty = 500;
        max_qty = 500;
 
 
      /* If this basic block is being extended by following certain jumps,
      /* If this basic block is being extended by following certain jumps,
         (see `cse_end_of_basic_block'), we reprocess the code from the start.
         (see `cse_end_of_basic_block'), we reprocess the code from the start.
         Otherwise, we start after this basic block.  */
         Otherwise, we start after this basic block.  */
      if (val.path_size > 0)
      if (val.path_size > 0)
        cse_basic_block (insn, val.last, val.path);
        cse_basic_block (insn, val.last, val.path);
      else
      else
        {
        {
          int old_cse_jumps_altered = cse_jumps_altered;
          int old_cse_jumps_altered = cse_jumps_altered;
          rtx temp;
          rtx temp;
 
 
          /* When cse changes a conditional jump to an unconditional
          /* When cse changes a conditional jump to an unconditional
             jump, we want to reprocess the block, since it will give
             jump, we want to reprocess the block, since it will give
             us a new branch path to investigate.  */
             us a new branch path to investigate.  */
          cse_jumps_altered = 0;
          cse_jumps_altered = 0;
          temp = cse_basic_block (insn, val.last, val.path);
          temp = cse_basic_block (insn, val.last, val.path);
          if (cse_jumps_altered == 0
          if (cse_jumps_altered == 0
              || (flag_cse_follow_jumps == 0 && flag_cse_skip_blocks == 0))
              || (flag_cse_follow_jumps == 0 && flag_cse_skip_blocks == 0))
            insn = temp;
            insn = temp;
 
 
          cse_jumps_altered |= old_cse_jumps_altered;
          cse_jumps_altered |= old_cse_jumps_altered;
        }
        }
 
 
      if (cse_altered)
      if (cse_altered)
        ggc_collect ();
        ggc_collect ();
 
 
#ifdef USE_C_ALLOCA
#ifdef USE_C_ALLOCA
      alloca (0);
      alloca (0);
#endif
#endif
    }
    }
 
 
  /* Clean up.  */
  /* Clean up.  */
  end_alias_analysis ();
  end_alias_analysis ();
  free (uid_cuid);
  free (uid_cuid);
  free (reg_eqv_table);
  free (reg_eqv_table);
  free (val.path);
  free (val.path);
  rtl_hooks = general_rtl_hooks;
  rtl_hooks = general_rtl_hooks;
 
 
  return cse_jumps_altered || recorded_label_ref;
  return cse_jumps_altered || recorded_label_ref;
}
}
 
 
/* Process a single basic block.  FROM and TO and the limits of the basic
/* Process a single basic block.  FROM and TO and the limits of the basic
   block.  NEXT_BRANCH points to the branch path when following jumps or
   block.  NEXT_BRANCH points to the branch path when following jumps or
   a null path when not following jumps.  */
   a null path when not following jumps.  */
 
 
static rtx
static rtx
cse_basic_block (rtx from, rtx to, struct branch_path *next_branch)
cse_basic_block (rtx from, rtx to, struct branch_path *next_branch)
{
{
  rtx insn;
  rtx insn;
  int to_usage = 0;
  int to_usage = 0;
  rtx libcall_insn = NULL_RTX;
  rtx libcall_insn = NULL_RTX;
  int num_insns = 0;
  int num_insns = 0;
  int no_conflict = 0;
  int no_conflict = 0;
 
 
  /* Allocate the space needed by qty_table.  */
  /* Allocate the space needed by qty_table.  */
  qty_table = XNEWVEC (struct qty_table_elem, max_qty);
  qty_table = XNEWVEC (struct qty_table_elem, max_qty);
 
 
  new_basic_block ();
  new_basic_block ();
 
 
  /* TO might be a label.  If so, protect it from being deleted.  */
  /* TO might be a label.  If so, protect it from being deleted.  */
  if (to != 0 && LABEL_P (to))
  if (to != 0 && LABEL_P (to))
    ++LABEL_NUSES (to);
    ++LABEL_NUSES (to);
 
 
  for (insn = from; insn != to; insn = NEXT_INSN (insn))
  for (insn = from; insn != to; insn = NEXT_INSN (insn))
    {
    {
      enum rtx_code code = GET_CODE (insn);
      enum rtx_code code = GET_CODE (insn);
 
 
      /* If we have processed 1,000 insns, flush the hash table to
      /* If we have processed 1,000 insns, flush the hash table to
         avoid extreme quadratic behavior.  We must not include NOTEs
         avoid extreme quadratic behavior.  We must not include NOTEs
         in the count since there may be more of them when generating
         in the count since there may be more of them when generating
         debugging information.  If we clear the table at different
         debugging information.  If we clear the table at different
         times, code generated with -g -O might be different than code
         times, code generated with -g -O might be different than code
         generated with -O but not -g.
         generated with -O but not -g.
 
 
         ??? This is a real kludge and needs to be done some other way.
         ??? This is a real kludge and needs to be done some other way.
         Perhaps for 2.9.  */
         Perhaps for 2.9.  */
      if (code != NOTE && num_insns++ > PARAM_VALUE (PARAM_MAX_CSE_INSNS))
      if (code != NOTE && num_insns++ > PARAM_VALUE (PARAM_MAX_CSE_INSNS))
        {
        {
          flush_hash_table ();
          flush_hash_table ();
          num_insns = 0;
          num_insns = 0;
        }
        }
 
 
      /* See if this is a branch that is part of the path.  If so, and it is
      /* See if this is a branch that is part of the path.  If so, and it is
         to be taken, do so.  */
         to be taken, do so.  */
      if (next_branch->branch == insn)
      if (next_branch->branch == insn)
        {
        {
          enum taken status = next_branch++->status;
          enum taken status = next_branch++->status;
          if (status != PATH_NOT_TAKEN)
          if (status != PATH_NOT_TAKEN)
            {
            {
              if (status == PATH_TAKEN)
              if (status == PATH_TAKEN)
                record_jump_equiv (insn, 1);
                record_jump_equiv (insn, 1);
              else
              else
                invalidate_skipped_block (NEXT_INSN (insn));
                invalidate_skipped_block (NEXT_INSN (insn));
 
 
              /* Set the last insn as the jump insn; it doesn't affect cc0.
              /* Set the last insn as the jump insn; it doesn't affect cc0.
                 Then follow this branch.  */
                 Then follow this branch.  */
#ifdef HAVE_cc0
#ifdef HAVE_cc0
              prev_insn_cc0 = 0;
              prev_insn_cc0 = 0;
              prev_insn = insn;
              prev_insn = insn;
#endif
#endif
              insn = JUMP_LABEL (insn);
              insn = JUMP_LABEL (insn);
              continue;
              continue;
            }
            }
        }
        }
 
 
      if (GET_MODE (insn) == QImode)
      if (GET_MODE (insn) == QImode)
        PUT_MODE (insn, VOIDmode);
        PUT_MODE (insn, VOIDmode);
 
 
      if (GET_RTX_CLASS (code) == RTX_INSN)
      if (GET_RTX_CLASS (code) == RTX_INSN)
        {
        {
          rtx p;
          rtx p;
 
 
          /* Process notes first so we have all notes in canonical forms when
          /* Process notes first so we have all notes in canonical forms when
             looking for duplicate operations.  */
             looking for duplicate operations.  */
 
 
          if (REG_NOTES (insn))
          if (REG_NOTES (insn))
            REG_NOTES (insn) = cse_process_notes (REG_NOTES (insn), NULL_RTX);
            REG_NOTES (insn) = cse_process_notes (REG_NOTES (insn), NULL_RTX);
 
 
          /* Track when we are inside in LIBCALL block.  Inside such a block,
          /* Track when we are inside in LIBCALL block.  Inside such a block,
             we do not want to record destinations.  The last insn of a
             we do not want to record destinations.  The last insn of a
             LIBCALL block is not considered to be part of the block, since
             LIBCALL block is not considered to be part of the block, since
             its destination is the result of the block and hence should be
             its destination is the result of the block and hence should be
             recorded.  */
             recorded.  */
 
 
          if (REG_NOTES (insn) != 0)
          if (REG_NOTES (insn) != 0)
            {
            {
              if ((p = find_reg_note (insn, REG_LIBCALL, NULL_RTX)))
              if ((p = find_reg_note (insn, REG_LIBCALL, NULL_RTX)))
                libcall_insn = XEXP (p, 0);
                libcall_insn = XEXP (p, 0);
              else if (find_reg_note (insn, REG_RETVAL, NULL_RTX))
              else if (find_reg_note (insn, REG_RETVAL, NULL_RTX))
                {
                {
                  /* Keep libcall_insn for the last SET insn of a no-conflict
                  /* Keep libcall_insn for the last SET insn of a no-conflict
                     block to prevent changing the destination.  */
                     block to prevent changing the destination.  */
                  if (! no_conflict)
                  if (! no_conflict)
                    libcall_insn = 0;
                    libcall_insn = 0;
                  else
                  else
                    no_conflict = -1;
                    no_conflict = -1;
                }
                }
              else if (find_reg_note (insn, REG_NO_CONFLICT, NULL_RTX))
              else if (find_reg_note (insn, REG_NO_CONFLICT, NULL_RTX))
                no_conflict = 1;
                no_conflict = 1;
            }
            }
 
 
          cse_insn (insn, libcall_insn);
          cse_insn (insn, libcall_insn);
 
 
          if (no_conflict == -1)
          if (no_conflict == -1)
            {
            {
              libcall_insn = 0;
              libcall_insn = 0;
              no_conflict = 0;
              no_conflict = 0;
            }
            }
 
 
          /* If we haven't already found an insn where we added a LABEL_REF,
          /* If we haven't already found an insn where we added a LABEL_REF,
             check this one.  */
             check this one.  */
          if (NONJUMP_INSN_P (insn) && ! recorded_label_ref
          if (NONJUMP_INSN_P (insn) && ! recorded_label_ref
              && for_each_rtx (&PATTERN (insn), check_for_label_ref,
              && for_each_rtx (&PATTERN (insn), check_for_label_ref,
                               (void *) insn))
                               (void *) insn))
            recorded_label_ref = 1;
            recorded_label_ref = 1;
        }
        }
 
 
      /* If INSN is now an unconditional jump, skip to the end of our
      /* If INSN is now an unconditional jump, skip to the end of our
         basic block by pretending that we just did the last insn in the
         basic block by pretending that we just did the last insn in the
         basic block.  If we are jumping to the end of our block, show
         basic block.  If we are jumping to the end of our block, show
         that we can have one usage of TO.  */
         that we can have one usage of TO.  */
 
 
      if (any_uncondjump_p (insn))
      if (any_uncondjump_p (insn))
        {
        {
          if (to == 0)
          if (to == 0)
            {
            {
              free (qty_table);
              free (qty_table);
              return 0;
              return 0;
            }
            }
 
 
          if (JUMP_LABEL (insn) == to)
          if (JUMP_LABEL (insn) == to)
            to_usage = 1;
            to_usage = 1;
 
 
          /* Maybe TO was deleted because the jump is unconditional.
          /* Maybe TO was deleted because the jump is unconditional.
             If so, there is nothing left in this basic block.  */
             If so, there is nothing left in this basic block.  */
          /* ??? Perhaps it would be smarter to set TO
          /* ??? Perhaps it would be smarter to set TO
             to whatever follows this insn,
             to whatever follows this insn,
             and pretend the basic block had always ended here.  */
             and pretend the basic block had always ended here.  */
          if (INSN_DELETED_P (to))
          if (INSN_DELETED_P (to))
            break;
            break;
 
 
          insn = PREV_INSN (to);
          insn = PREV_INSN (to);
        }
        }
 
 
      /* See if it is ok to keep on going past the label
      /* See if it is ok to keep on going past the label
         which used to end our basic block.  Remember that we incremented
         which used to end our basic block.  Remember that we incremented
         the count of that label, so we decrement it here.  If we made
         the count of that label, so we decrement it here.  If we made
         a jump unconditional, TO_USAGE will be one; in that case, we don't
         a jump unconditional, TO_USAGE will be one; in that case, we don't
         want to count the use in that jump.  */
         want to count the use in that jump.  */
 
 
      if (to != 0 && NEXT_INSN (insn) == to
      if (to != 0 && NEXT_INSN (insn) == to
          && LABEL_P (to) && --LABEL_NUSES (to) == to_usage)
          && LABEL_P (to) && --LABEL_NUSES (to) == to_usage)
        {
        {
          struct cse_basic_block_data val;
          struct cse_basic_block_data val;
          rtx prev;
          rtx prev;
 
 
          insn = NEXT_INSN (to);
          insn = NEXT_INSN (to);
 
 
          /* If TO was the last insn in the function, we are done.  */
          /* If TO was the last insn in the function, we are done.  */
          if (insn == 0)
          if (insn == 0)
            {
            {
              free (qty_table);
              free (qty_table);
              return 0;
              return 0;
            }
            }
 
 
          /* If TO was preceded by a BARRIER we are done with this block
          /* If TO was preceded by a BARRIER we are done with this block
             because it has no continuation.  */
             because it has no continuation.  */
          prev = prev_nonnote_insn (to);
          prev = prev_nonnote_insn (to);
          if (prev && BARRIER_P (prev))
          if (prev && BARRIER_P (prev))
            {
            {
              free (qty_table);
              free (qty_table);
              return insn;
              return insn;
            }
            }
 
 
          /* Find the end of the following block.  Note that we won't be
          /* Find the end of the following block.  Note that we won't be
             following branches in this case.  */
             following branches in this case.  */
          to_usage = 0;
          to_usage = 0;
          val.path_size = 0;
          val.path_size = 0;
          val.path = XNEWVEC (struct branch_path, PARAM_VALUE (PARAM_MAX_CSE_PATH_LENGTH));
          val.path = XNEWVEC (struct branch_path, PARAM_VALUE (PARAM_MAX_CSE_PATH_LENGTH));
          cse_end_of_basic_block (insn, &val, 0, 0);
          cse_end_of_basic_block (insn, &val, 0, 0);
          free (val.path);
          free (val.path);
 
 
          /* If the tables we allocated have enough space left
          /* If the tables we allocated have enough space left
             to handle all the SETs in the next basic block,
             to handle all the SETs in the next basic block,
             continue through it.  Otherwise, return,
             continue through it.  Otherwise, return,
             and that block will be scanned individually.  */
             and that block will be scanned individually.  */
          if (val.nsets * 2 + next_qty > max_qty)
          if (val.nsets * 2 + next_qty > max_qty)
            break;
            break;
 
 
          cse_basic_block_start = val.low_cuid;
          cse_basic_block_start = val.low_cuid;
          cse_basic_block_end = val.high_cuid;
          cse_basic_block_end = val.high_cuid;
          to = val.last;
          to = val.last;
 
 
          /* Prevent TO from being deleted if it is a label.  */
          /* Prevent TO from being deleted if it is a label.  */
          if (to != 0 && LABEL_P (to))
          if (to != 0 && LABEL_P (to))
            ++LABEL_NUSES (to);
            ++LABEL_NUSES (to);
 
 
          /* Back up so we process the first insn in the extension.  */
          /* Back up so we process the first insn in the extension.  */
          insn = PREV_INSN (insn);
          insn = PREV_INSN (insn);
        }
        }
    }
    }
 
 
  gcc_assert (next_qty <= max_qty);
  gcc_assert (next_qty <= max_qty);
 
 
  free (qty_table);
  free (qty_table);
 
 
  return to ? NEXT_INSN (to) : 0;
  return to ? NEXT_INSN (to) : 0;
}
}


/* Called via for_each_rtx to see if an insn is using a LABEL_REF for which
/* Called via for_each_rtx to see if an insn is using a LABEL_REF for which
   there isn't a REG_LABEL note.  Return one if so.  DATA is the insn.  */
   there isn't a REG_LABEL note.  Return one if so.  DATA is the insn.  */
 
 
static int
static int
check_for_label_ref (rtx *rtl, void *data)
check_for_label_ref (rtx *rtl, void *data)
{
{
  rtx insn = (rtx) data;
  rtx insn = (rtx) data;
 
 
  /* If this insn uses a LABEL_REF and there isn't a REG_LABEL note for it,
  /* If this insn uses a LABEL_REF and there isn't a REG_LABEL note for it,
     we must rerun jump since it needs to place the note.  If this is a
     we must rerun jump since it needs to place the note.  If this is a
     LABEL_REF for a CODE_LABEL that isn't in the insn chain, don't do this
     LABEL_REF for a CODE_LABEL that isn't in the insn chain, don't do this
     since no REG_LABEL will be added.  */
     since no REG_LABEL will be added.  */
  return (GET_CODE (*rtl) == LABEL_REF
  return (GET_CODE (*rtl) == LABEL_REF
          && ! LABEL_REF_NONLOCAL_P (*rtl)
          && ! LABEL_REF_NONLOCAL_P (*rtl)
          && LABEL_P (XEXP (*rtl, 0))
          && LABEL_P (XEXP (*rtl, 0))
          && INSN_UID (XEXP (*rtl, 0)) != 0
          && INSN_UID (XEXP (*rtl, 0)) != 0
          && ! find_reg_note (insn, REG_LABEL, XEXP (*rtl, 0)));
          && ! find_reg_note (insn, REG_LABEL, XEXP (*rtl, 0)));
}
}


/* Count the number of times registers are used (not set) in X.
/* Count the number of times registers are used (not set) in X.
   COUNTS is an array in which we accumulate the count, INCR is how much
   COUNTS is an array in which we accumulate the count, INCR is how much
   we count each register usage.
   we count each register usage.
 
 
   Don't count a usage of DEST, which is the SET_DEST of a SET which
   Don't count a usage of DEST, which is the SET_DEST of a SET which
   contains X in its SET_SRC.  This is because such a SET does not
   contains X in its SET_SRC.  This is because such a SET does not
   modify the liveness of DEST.
   modify the liveness of DEST.
   DEST is set to pc_rtx for a trapping insn, which means that we must count
   DEST is set to pc_rtx for a trapping insn, which means that we must count
   uses of a SET_DEST regardless because the insn can't be deleted here.  */
   uses of a SET_DEST regardless because the insn can't be deleted here.  */
 
 
static void
static void
count_reg_usage (rtx x, int *counts, rtx dest, int incr)
count_reg_usage (rtx x, int *counts, rtx dest, int incr)
{
{
  enum rtx_code code;
  enum rtx_code code;
  rtx note;
  rtx note;
  const char *fmt;
  const char *fmt;
  int i, j;
  int i, j;
 
 
  if (x == 0)
  if (x == 0)
    return;
    return;
 
 
  switch (code = GET_CODE (x))
  switch (code = GET_CODE (x))
    {
    {
    case REG:
    case REG:
      if (x != dest)
      if (x != dest)
        counts[REGNO (x)] += incr;
        counts[REGNO (x)] += incr;
      return;
      return;
 
 
    case PC:
    case PC:
    case CC0:
    case CC0:
    case CONST:
    case CONST:
    case CONST_INT:
    case CONST_INT:
    case CONST_DOUBLE:
    case CONST_DOUBLE:
    case CONST_VECTOR:
    case CONST_VECTOR:
    case SYMBOL_REF:
    case SYMBOL_REF:
    case LABEL_REF:
    case LABEL_REF:
      return;
      return;
 
 
    case CLOBBER:
    case CLOBBER:
      /* If we are clobbering a MEM, mark any registers inside the address
      /* If we are clobbering a MEM, mark any registers inside the address
         as being used.  */
         as being used.  */
      if (MEM_P (XEXP (x, 0)))
      if (MEM_P (XEXP (x, 0)))
        count_reg_usage (XEXP (XEXP (x, 0), 0), counts, NULL_RTX, incr);
        count_reg_usage (XEXP (XEXP (x, 0), 0), counts, NULL_RTX, incr);
      return;
      return;
 
 
    case SET:
    case SET:
      /* Unless we are setting a REG, count everything in SET_DEST.  */
      /* Unless we are setting a REG, count everything in SET_DEST.  */
      if (!REG_P (SET_DEST (x)))
      if (!REG_P (SET_DEST (x)))
        count_reg_usage (SET_DEST (x), counts, NULL_RTX, incr);
        count_reg_usage (SET_DEST (x), counts, NULL_RTX, incr);
      count_reg_usage (SET_SRC (x), counts,
      count_reg_usage (SET_SRC (x), counts,
                       dest ? dest : SET_DEST (x),
                       dest ? dest : SET_DEST (x),
                       incr);
                       incr);
      return;
      return;
 
 
    case CALL_INSN:
    case CALL_INSN:
    case INSN:
    case INSN:
    case JUMP_INSN:
    case JUMP_INSN:
    /* We expect dest to be NULL_RTX here.  If the insn may trap, mark
    /* We expect dest to be NULL_RTX here.  If the insn may trap, mark
       this fact by setting DEST to pc_rtx.  */
       this fact by setting DEST to pc_rtx.  */
      if (flag_non_call_exceptions && may_trap_p (PATTERN (x)))
      if (flag_non_call_exceptions && may_trap_p (PATTERN (x)))
        dest = pc_rtx;
        dest = pc_rtx;
      if (code == CALL_INSN)
      if (code == CALL_INSN)
        count_reg_usage (CALL_INSN_FUNCTION_USAGE (x), counts, dest, incr);
        count_reg_usage (CALL_INSN_FUNCTION_USAGE (x), counts, dest, incr);
      count_reg_usage (PATTERN (x), counts, dest, incr);
      count_reg_usage (PATTERN (x), counts, dest, incr);
 
 
      /* Things used in a REG_EQUAL note aren't dead since loop may try to
      /* Things used in a REG_EQUAL note aren't dead since loop may try to
         use them.  */
         use them.  */
 
 
      note = find_reg_equal_equiv_note (x);
      note = find_reg_equal_equiv_note (x);
      if (note)
      if (note)
        {
        {
          rtx eqv = XEXP (note, 0);
          rtx eqv = XEXP (note, 0);
 
 
          if (GET_CODE (eqv) == EXPR_LIST)
          if (GET_CODE (eqv) == EXPR_LIST)
          /* This REG_EQUAL note describes the result of a function call.
          /* This REG_EQUAL note describes the result of a function call.
             Process all the arguments.  */
             Process all the arguments.  */
            do
            do
              {
              {
                count_reg_usage (XEXP (eqv, 0), counts, dest, incr);
                count_reg_usage (XEXP (eqv, 0), counts, dest, incr);
                eqv = XEXP (eqv, 1);
                eqv = XEXP (eqv, 1);
              }
              }
            while (eqv && GET_CODE (eqv) == EXPR_LIST);
            while (eqv && GET_CODE (eqv) == EXPR_LIST);
          else
          else
            count_reg_usage (eqv, counts, dest, incr);
            count_reg_usage (eqv, counts, dest, incr);
        }
        }
      return;
      return;
 
 
    case EXPR_LIST:
    case EXPR_LIST:
      if (REG_NOTE_KIND (x) == REG_EQUAL
      if (REG_NOTE_KIND (x) == REG_EQUAL
          || (REG_NOTE_KIND (x) != REG_NONNEG && GET_CODE (XEXP (x,0)) == USE)
          || (REG_NOTE_KIND (x) != REG_NONNEG && GET_CODE (XEXP (x,0)) == USE)
          /* FUNCTION_USAGE expression lists may include (CLOBBER (mem /u)),
          /* FUNCTION_USAGE expression lists may include (CLOBBER (mem /u)),
             involving registers in the address.  */
             involving registers in the address.  */
          || GET_CODE (XEXP (x, 0)) == CLOBBER)
          || GET_CODE (XEXP (x, 0)) == CLOBBER)
        count_reg_usage (XEXP (x, 0), counts, NULL_RTX, incr);
        count_reg_usage (XEXP (x, 0), counts, NULL_RTX, incr);
 
 
      count_reg_usage (XEXP (x, 1), counts, NULL_RTX, incr);
      count_reg_usage (XEXP (x, 1), counts, NULL_RTX, incr);
      return;
      return;
 
 
    case ASM_OPERANDS:
    case ASM_OPERANDS:
      /* If the asm is volatile, then this insn cannot be deleted,
      /* If the asm is volatile, then this insn cannot be deleted,
         and so the inputs *must* be live.  */
         and so the inputs *must* be live.  */
      if (MEM_VOLATILE_P (x))
      if (MEM_VOLATILE_P (x))
        dest = NULL_RTX;
        dest = NULL_RTX;
      /* Iterate over just the inputs, not the constraints as well.  */
      /* Iterate over just the inputs, not the constraints as well.  */
      for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--)
      for (i = ASM_OPERANDS_INPUT_LENGTH (x) - 1; i >= 0; i--)
        count_reg_usage (ASM_OPERANDS_INPUT (x, i), counts, dest, incr);
        count_reg_usage (ASM_OPERANDS_INPUT (x, i), counts, dest, incr);
      return;
      return;
 
 
    case INSN_LIST:
    case INSN_LIST:
      gcc_unreachable ();
      gcc_unreachable ();
 
 
    default:
    default:
      break;
      break;
    }
    }
 
 
  fmt = GET_RTX_FORMAT (code);
  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
    {
      if (fmt[i] == 'e')
      if (fmt[i] == 'e')
        count_reg_usage (XEXP (x, i), counts, dest, incr);
        count_reg_usage (XEXP (x, i), counts, dest, incr);
      else if (fmt[i] == 'E')
      else if (fmt[i] == 'E')
        for (j = XVECLEN (x, i) - 1; j >= 0; j--)
        for (j = XVECLEN (x, i) - 1; j >= 0; j--)
          count_reg_usage (XVECEXP (x, i, j), counts, dest, incr);
          count_reg_usage (XVECEXP (x, i, j), counts, dest, incr);
    }
    }
}
}


/* Return true if set is live.  */
/* Return true if set is live.  */
static bool
static bool
set_live_p (rtx set, rtx insn ATTRIBUTE_UNUSED, /* Only used with HAVE_cc0.  */
set_live_p (rtx set, rtx insn ATTRIBUTE_UNUSED, /* Only used with HAVE_cc0.  */
            int *counts)
            int *counts)
{
{
#ifdef HAVE_cc0
#ifdef HAVE_cc0
  rtx tem;
  rtx tem;
#endif
#endif
 
 
  if (set_noop_p (set))
  if (set_noop_p (set))
    ;
    ;
 
 
#ifdef HAVE_cc0
#ifdef HAVE_cc0
  else if (GET_CODE (SET_DEST (set)) == CC0
  else if (GET_CODE (SET_DEST (set)) == CC0
           && !side_effects_p (SET_SRC (set))
           && !side_effects_p (SET_SRC (set))
           && ((tem = next_nonnote_insn (insn)) == 0
           && ((tem = next_nonnote_insn (insn)) == 0
               || !INSN_P (tem)
               || !INSN_P (tem)
               || !reg_referenced_p (cc0_rtx, PATTERN (tem))))
               || !reg_referenced_p (cc0_rtx, PATTERN (tem))))
    return false;
    return false;
#endif
#endif
  else if (!REG_P (SET_DEST (set))
  else if (!REG_P (SET_DEST (set))
           || REGNO (SET_DEST (set)) < FIRST_PSEUDO_REGISTER
           || REGNO (SET_DEST (set)) < FIRST_PSEUDO_REGISTER
           || counts[REGNO (SET_DEST (set))] != 0
           || counts[REGNO (SET_DEST (set))] != 0
           || side_effects_p (SET_SRC (set)))
           || side_effects_p (SET_SRC (set)))
    return true;
    return true;
  return false;
  return false;
}
}
 
 
/* Return true if insn is live.  */
/* Return true if insn is live.  */
 
 
static bool
static bool
insn_live_p (rtx insn, int *counts)
insn_live_p (rtx insn, int *counts)
{
{
  int i;
  int i;
  if (flag_non_call_exceptions && may_trap_p (PATTERN (insn)))
  if (flag_non_call_exceptions && may_trap_p (PATTERN (insn)))
    return true;
    return true;
  else if (GET_CODE (PATTERN (insn)) == SET)
  else if (GET_CODE (PATTERN (insn)) == SET)
    return set_live_p (PATTERN (insn), insn, counts);
    return set_live_p (PATTERN (insn), insn, counts);
  else if (GET_CODE (PATTERN (insn)) == PARALLEL)
  else if (GET_CODE (PATTERN (insn)) == PARALLEL)
    {
    {
      for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
      for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
        {
        {
          rtx elt = XVECEXP (PATTERN (insn), 0, i);
          rtx elt = XVECEXP (PATTERN (insn), 0, i);
 
 
          if (GET_CODE (elt) == SET)
          if (GET_CODE (elt) == SET)
            {
            {
              if (set_live_p (elt, insn, counts))
              if (set_live_p (elt, insn, counts))
                return true;
                return true;
            }
            }
          else if (GET_CODE (elt) != CLOBBER && GET_CODE (elt) != USE)
          else if (GET_CODE (elt) != CLOBBER && GET_CODE (elt) != USE)
            return true;
            return true;
        }
        }
      return false;
      return false;
    }
    }
  else
  else
    return true;
    return true;
}
}
 
 
/* Return true if libcall is dead as a whole.  */
/* Return true if libcall is dead as a whole.  */
 
 
static bool
static bool
dead_libcall_p (rtx insn, int *counts)
dead_libcall_p (rtx insn, int *counts)
{
{
  rtx note, set, new;
  rtx note, set, new;
 
 
  /* See if there's a REG_EQUAL note on this insn and try to
  /* See if there's a REG_EQUAL note on this insn and try to
     replace the source with the REG_EQUAL expression.
     replace the source with the REG_EQUAL expression.
 
 
     We assume that insns with REG_RETVALs can only be reg->reg
     We assume that insns with REG_RETVALs can only be reg->reg
     copies at this point.  */
     copies at this point.  */
  note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
  note = find_reg_note (insn, REG_EQUAL, NULL_RTX);
  if (!note)
  if (!note)
    return false;
    return false;
 
 
  set = single_set (insn);
  set = single_set (insn);
  if (!set)
  if (!set)
    return false;
    return false;
 
 
  new = simplify_rtx (XEXP (note, 0));
  new = simplify_rtx (XEXP (note, 0));
  if (!new)
  if (!new)
    new = XEXP (note, 0);
    new = XEXP (note, 0);
 
 
  /* While changing insn, we must update the counts accordingly.  */
  /* While changing insn, we must update the counts accordingly.  */
  count_reg_usage (insn, counts, NULL_RTX, -1);
  count_reg_usage (insn, counts, NULL_RTX, -1);
 
 
  if (validate_change (insn, &SET_SRC (set), new, 0))
  if (validate_change (insn, &SET_SRC (set), new, 0))
    {
    {
      count_reg_usage (insn, counts, NULL_RTX, 1);
      count_reg_usage (insn, counts, NULL_RTX, 1);
      remove_note (insn, find_reg_note (insn, REG_RETVAL, NULL_RTX));
      remove_note (insn, find_reg_note (insn, REG_RETVAL, NULL_RTX));
      remove_note (insn, note);
      remove_note (insn, note);
      return true;
      return true;
    }
    }
 
 
  if (CONSTANT_P (new))
  if (CONSTANT_P (new))
    {
    {
      new = force_const_mem (GET_MODE (SET_DEST (set)), new);
      new = force_const_mem (GET_MODE (SET_DEST (set)), new);
      if (new && validate_change (insn, &SET_SRC (set), new, 0))
      if (new && validate_change (insn, &SET_SRC (set), new, 0))
        {
        {
          count_reg_usage (insn, counts, NULL_RTX, 1);
          count_reg_usage (insn, counts, NULL_RTX, 1);
          remove_note (insn, find_reg_note (insn, REG_RETVAL, NULL_RTX));
          remove_note (insn, find_reg_note (insn, REG_RETVAL, NULL_RTX));
          remove_note (insn, note);
          remove_note (insn, note);
          return true;
          return true;
        }
        }
    }
    }
 
 
  count_reg_usage (insn, counts, NULL_RTX, 1);
  count_reg_usage (insn, counts, NULL_RTX, 1);
  return false;
  return false;
}
}
 
 
/* Scan all the insns and delete any that are dead; i.e., they store a register
/* Scan all the insns and delete any that are dead; i.e., they store a register
   that is never used or they copy a register to itself.
   that is never used or they copy a register to itself.
 
 
   This is used to remove insns made obviously dead by cse, loop or other
   This is used to remove insns made obviously dead by cse, loop or other
   optimizations.  It improves the heuristics in loop since it won't try to
   optimizations.  It improves the heuristics in loop since it won't try to
   move dead invariants out of loops or make givs for dead quantities.  The
   move dead invariants out of loops or make givs for dead quantities.  The
   remaining passes of the compilation are also sped up.  */
   remaining passes of the compilation are also sped up.  */
 
 
int
int
delete_trivially_dead_insns (rtx insns, int nreg)
delete_trivially_dead_insns (rtx insns, int nreg)
{
{
  int *counts;
  int *counts;
  rtx insn, prev;
  rtx insn, prev;
  int in_libcall = 0, dead_libcall = 0;
  int in_libcall = 0, dead_libcall = 0;
  int ndead = 0;
  int ndead = 0;
 
 
  timevar_push (TV_DELETE_TRIVIALLY_DEAD);
  timevar_push (TV_DELETE_TRIVIALLY_DEAD);
  /* First count the number of times each register is used.  */
  /* First count the number of times each register is used.  */
  counts = XCNEWVEC (int, nreg);
  counts = XCNEWVEC (int, nreg);
  for (insn = insns; insn; insn = NEXT_INSN (insn))
  for (insn = insns; insn; insn = NEXT_INSN (insn))
    if (INSN_P (insn))
    if (INSN_P (insn))
      count_reg_usage (insn, counts, NULL_RTX, 1);
      count_reg_usage (insn, counts, NULL_RTX, 1);
 
 
  /* Go from the last insn to the first and delete insns that only set unused
  /* Go from the last insn to the first and delete insns that only set unused
     registers or copy a register to itself.  As we delete an insn, remove
     registers or copy a register to itself.  As we delete an insn, remove
     usage counts for registers it uses.
     usage counts for registers it uses.
 
 
     The first jump optimization pass may leave a real insn as the last
     The first jump optimization pass may leave a real insn as the last
     insn in the function.   We must not skip that insn or we may end
     insn in the function.   We must not skip that insn or we may end
     up deleting code that is not really dead.  */
     up deleting code that is not really dead.  */
  for (insn = get_last_insn (); insn; insn = prev)
  for (insn = get_last_insn (); insn; insn = prev)
    {
    {
      int live_insn = 0;
      int live_insn = 0;
 
 
      prev = PREV_INSN (insn);
      prev = PREV_INSN (insn);
      if (!INSN_P (insn))
      if (!INSN_P (insn))
        continue;
        continue;
 
 
      /* Don't delete any insns that are part of a libcall block unless
      /* Don't delete any insns that are part of a libcall block unless
         we can delete the whole libcall block.
         we can delete the whole libcall block.
 
 
         Flow or loop might get confused if we did that.  Remember
         Flow or loop might get confused if we did that.  Remember
         that we are scanning backwards.  */
         that we are scanning backwards.  */
      if (find_reg_note (insn, REG_RETVAL, NULL_RTX))
      if (find_reg_note (insn, REG_RETVAL, NULL_RTX))
        {
        {
          in_libcall = 1;
          in_libcall = 1;
          live_insn = 1;
          live_insn = 1;
          dead_libcall = dead_libcall_p (insn, counts);
          dead_libcall = dead_libcall_p (insn, counts);
        }
        }
      else if (in_libcall)
      else if (in_libcall)
        live_insn = ! dead_libcall;
        live_insn = ! dead_libcall;
      else
      else
        live_insn = insn_live_p (insn, counts);
        live_insn = insn_live_p (insn, counts);
 
 
      /* If this is a dead insn, delete it and show registers in it aren't
      /* If this is a dead insn, delete it and show registers in it aren't
         being used.  */
         being used.  */
 
 
      if (! live_insn)
      if (! live_insn)
        {
        {
          count_reg_usage (insn, counts, NULL_RTX, -1);
          count_reg_usage (insn, counts, NULL_RTX, -1);
          delete_insn_and_edges (insn);
          delete_insn_and_edges (insn);
          ndead++;
          ndead++;
        }
        }
 
 
      if (in_libcall && find_reg_note (insn, REG_LIBCALL, NULL_RTX))
      if (in_libcall && find_reg_note (insn, REG_LIBCALL, NULL_RTX))
        {
        {
          in_libcall = 0;
          in_libcall = 0;
          dead_libcall = 0;
          dead_libcall = 0;
        }
        }
    }
    }
 
 
  if (dump_file && ndead)
  if (dump_file && ndead)
    fprintf (dump_file, "Deleted %i trivially dead insns\n",
    fprintf (dump_file, "Deleted %i trivially dead insns\n",
             ndead);
             ndead);
  /* Clean up.  */
  /* Clean up.  */
  free (counts);
  free (counts);
  timevar_pop (TV_DELETE_TRIVIALLY_DEAD);
  timevar_pop (TV_DELETE_TRIVIALLY_DEAD);
  return ndead;
  return ndead;
}
}
 
 
/* This function is called via for_each_rtx.  The argument, NEWREG, is
/* This function is called via for_each_rtx.  The argument, NEWREG, is
   a condition code register with the desired mode.  If we are looking
   a condition code register with the desired mode.  If we are looking
   at the same register in a different mode, replace it with
   at the same register in a different mode, replace it with
   NEWREG.  */
   NEWREG.  */
 
 
static int
static int
cse_change_cc_mode (rtx *loc, void *data)
cse_change_cc_mode (rtx *loc, void *data)
{
{
  struct change_cc_mode_args* args = (struct change_cc_mode_args*)data;
  struct change_cc_mode_args* args = (struct change_cc_mode_args*)data;
 
 
  if (*loc
  if (*loc
      && REG_P (*loc)
      && REG_P (*loc)
      && REGNO (*loc) == REGNO (args->newreg)
      && REGNO (*loc) == REGNO (args->newreg)
      && GET_MODE (*loc) != GET_MODE (args->newreg))
      && GET_MODE (*loc) != GET_MODE (args->newreg))
    {
    {
      validate_change (args->insn, loc, args->newreg, 1);
      validate_change (args->insn, loc, args->newreg, 1);
 
 
      return -1;
      return -1;
    }
    }
  return 0;
  return 0;
}
}
 
 
/* Change the mode of any reference to the register REGNO (NEWREG) to
/* Change the mode of any reference to the register REGNO (NEWREG) to
   GET_MODE (NEWREG) in INSN.  */
   GET_MODE (NEWREG) in INSN.  */
 
 
static void
static void
cse_change_cc_mode_insn (rtx insn, rtx newreg)
cse_change_cc_mode_insn (rtx insn, rtx newreg)
{
{
  struct change_cc_mode_args args;
  struct change_cc_mode_args args;
  int success;
  int success;
 
 
  if (!INSN_P (insn))
  if (!INSN_P (insn))
    return;
    return;
 
 
  args.insn = insn;
  args.insn = insn;
  args.newreg = newreg;
  args.newreg = newreg;
 
 
  for_each_rtx (&PATTERN (insn), cse_change_cc_mode, &args);
  for_each_rtx (&PATTERN (insn), cse_change_cc_mode, &args);
  for_each_rtx (&REG_NOTES (insn), cse_change_cc_mode, &args);
  for_each_rtx (&REG_NOTES (insn), cse_change_cc_mode, &args);
 
 
  /* If the following assertion was triggered, there is most probably
  /* If the following assertion was triggered, there is most probably
     something wrong with the cc_modes_compatible back end function.
     something wrong with the cc_modes_compatible back end function.
     CC modes only can be considered compatible if the insn - with the mode
     CC modes only can be considered compatible if the insn - with the mode
     replaced by any of the compatible modes - can still be recognized.  */
     replaced by any of the compatible modes - can still be recognized.  */
  success = apply_change_group ();
  success = apply_change_group ();
  gcc_assert (success);
  gcc_assert (success);
}
}
 
 
/* Change the mode of any reference to the register REGNO (NEWREG) to
/* Change the mode of any reference to the register REGNO (NEWREG) to
   GET_MODE (NEWREG), starting at START.  Stop before END.  Stop at
   GET_MODE (NEWREG), starting at START.  Stop before END.  Stop at
   any instruction which modifies NEWREG.  */
   any instruction which modifies NEWREG.  */
 
 
static void
static void
cse_change_cc_mode_insns (rtx start, rtx end, rtx newreg)
cse_change_cc_mode_insns (rtx start, rtx end, rtx newreg)
{
{
  rtx insn;
  rtx insn;
 
 
  for (insn = start; insn != end; insn = NEXT_INSN (insn))
  for (insn = start; insn != end; insn = NEXT_INSN (insn))
    {
    {
      if (! INSN_P (insn))
      if (! INSN_P (insn))
        continue;
        continue;
 
 
      if (reg_set_p (newreg, insn))
      if (reg_set_p (newreg, insn))
        return;
        return;
 
 
      cse_change_cc_mode_insn (insn, newreg);
      cse_change_cc_mode_insn (insn, newreg);
    }
    }
}
}
 
 
/* BB is a basic block which finishes with CC_REG as a condition code
/* BB is a basic block which finishes with CC_REG as a condition code
   register which is set to CC_SRC.  Look through the successors of BB
   register which is set to CC_SRC.  Look through the successors of BB
   to find blocks which have a single predecessor (i.e., this one),
   to find blocks which have a single predecessor (i.e., this one),
   and look through those blocks for an assignment to CC_REG which is
   and look through those blocks for an assignment to CC_REG which is
   equivalent to CC_SRC.  CAN_CHANGE_MODE indicates whether we are
   equivalent to CC_SRC.  CAN_CHANGE_MODE indicates whether we are
   permitted to change the mode of CC_SRC to a compatible mode.  This
   permitted to change the mode of CC_SRC to a compatible mode.  This
   returns VOIDmode if no equivalent assignments were found.
   returns VOIDmode if no equivalent assignments were found.
   Otherwise it returns the mode which CC_SRC should wind up with.
   Otherwise it returns the mode which CC_SRC should wind up with.
 
 
   The main complexity in this function is handling the mode issues.
   The main complexity in this function is handling the mode issues.
   We may have more than one duplicate which we can eliminate, and we
   We may have more than one duplicate which we can eliminate, and we
   try to find a mode which will work for multiple duplicates.  */
   try to find a mode which will work for multiple duplicates.  */
 
 
static enum machine_mode
static enum machine_mode
cse_cc_succs (basic_block bb, rtx cc_reg, rtx cc_src, bool can_change_mode)
cse_cc_succs (basic_block bb, rtx cc_reg, rtx cc_src, bool can_change_mode)
{
{
  bool found_equiv;
  bool found_equiv;
  enum machine_mode mode;
  enum machine_mode mode;
  unsigned int insn_count;
  unsigned int insn_count;
  edge e;
  edge e;
  rtx insns[2];
  rtx insns[2];
  enum machine_mode modes[2];
  enum machine_mode modes[2];
  rtx last_insns[2];
  rtx last_insns[2];
  unsigned int i;
  unsigned int i;
  rtx newreg;
  rtx newreg;
  edge_iterator ei;
  edge_iterator ei;
 
 
  /* We expect to have two successors.  Look at both before picking
  /* We expect to have two successors.  Look at both before picking
     the final mode for the comparison.  If we have more successors
     the final mode for the comparison.  If we have more successors
     (i.e., some sort of table jump, although that seems unlikely),
     (i.e., some sort of table jump, although that seems unlikely),
     then we require all beyond the first two to use the same
     then we require all beyond the first two to use the same
     mode.  */
     mode.  */
 
 
  found_equiv = false;
  found_equiv = false;
  mode = GET_MODE (cc_src);
  mode = GET_MODE (cc_src);
  insn_count = 0;
  insn_count = 0;
  FOR_EACH_EDGE (e, ei, bb->succs)
  FOR_EACH_EDGE (e, ei, bb->succs)
    {
    {
      rtx insn;
      rtx insn;
      rtx end;
      rtx end;
 
 
      if (e->flags & EDGE_COMPLEX)
      if (e->flags & EDGE_COMPLEX)
        continue;
        continue;
 
 
      if (EDGE_COUNT (e->dest->preds) != 1
      if (EDGE_COUNT (e->dest->preds) != 1
          || e->dest == EXIT_BLOCK_PTR)
          || e->dest == EXIT_BLOCK_PTR)
        continue;
        continue;
 
 
      end = NEXT_INSN (BB_END (e->dest));
      end = NEXT_INSN (BB_END (e->dest));
      for (insn = BB_HEAD (e->dest); insn != end; insn = NEXT_INSN (insn))
      for (insn = BB_HEAD (e->dest); insn != end; insn = NEXT_INSN (insn))
        {
        {
          rtx set;
          rtx set;
 
 
          if (! INSN_P (insn))
          if (! INSN_P (insn))
            continue;
            continue;
 
 
          /* If CC_SRC is modified, we have to stop looking for
          /* If CC_SRC is modified, we have to stop looking for
             something which uses it.  */
             something which uses it.  */
          if (modified_in_p (cc_src, insn))
          if (modified_in_p (cc_src, insn))
            break;
            break;
 
 
          /* Check whether INSN sets CC_REG to CC_SRC.  */
          /* Check whether INSN sets CC_REG to CC_SRC.  */
          set = single_set (insn);
          set = single_set (insn);
          if (set
          if (set
              && REG_P (SET_DEST (set))
              && REG_P (SET_DEST (set))
              && REGNO (SET_DEST (set)) == REGNO (cc_reg))
              && REGNO (SET_DEST (set)) == REGNO (cc_reg))
            {
            {
              bool found;
              bool found;
              enum machine_mode set_mode;
              enum machine_mode set_mode;
              enum machine_mode comp_mode;
              enum machine_mode comp_mode;
 
 
              found = false;
              found = false;
              set_mode = GET_MODE (SET_SRC (set));
              set_mode = GET_MODE (SET_SRC (set));
              comp_mode = set_mode;
              comp_mode = set_mode;
              if (rtx_equal_p (cc_src, SET_SRC (set)))
              if (rtx_equal_p (cc_src, SET_SRC (set)))
                found = true;
                found = true;
              else if (GET_CODE (cc_src) == COMPARE
              else if (GET_CODE (cc_src) == COMPARE
                       && GET_CODE (SET_SRC (set)) == COMPARE
                       && GET_CODE (SET_SRC (set)) == COMPARE
                       && mode != set_mode
                       && mode != set_mode
                       && rtx_equal_p (XEXP (cc_src, 0),
                       && rtx_equal_p (XEXP (cc_src, 0),
                                       XEXP (SET_SRC (set), 0))
                                       XEXP (SET_SRC (set), 0))
                       && rtx_equal_p (XEXP (cc_src, 1),
                       && rtx_equal_p (XEXP (cc_src, 1),
                                       XEXP (SET_SRC (set), 1)))
                                       XEXP (SET_SRC (set), 1)))
 
 
                {
                {
                  comp_mode = targetm.cc_modes_compatible (mode, set_mode);
                  comp_mode = targetm.cc_modes_compatible (mode, set_mode);
                  if (comp_mode != VOIDmode
                  if (comp_mode != VOIDmode
                      && (can_change_mode || comp_mode == mode))
                      && (can_change_mode || comp_mode == mode))
                    found = true;
                    found = true;
                }
                }
 
 
              if (found)
              if (found)
                {
                {
                  found_equiv = true;
                  found_equiv = true;
                  if (insn_count < ARRAY_SIZE (insns))
                  if (insn_count < ARRAY_SIZE (insns))
                    {
                    {
                      insns[insn_count] = insn;
                      insns[insn_count] = insn;
                      modes[insn_count] = set_mode;
                      modes[insn_count] = set_mode;
                      last_insns[insn_count] = end;
                      last_insns[insn_count] = end;
                      ++insn_count;
                      ++insn_count;
 
 
                      if (mode != comp_mode)
                      if (mode != comp_mode)
                        {
                        {
                          gcc_assert (can_change_mode);
                          gcc_assert (can_change_mode);
                          mode = comp_mode;
                          mode = comp_mode;
 
 
                          /* The modified insn will be re-recognized later.  */
                          /* The modified insn will be re-recognized later.  */
                          PUT_MODE (cc_src, mode);
                          PUT_MODE (cc_src, mode);
                        }
                        }
                    }
                    }
                  else
                  else
                    {
                    {
                      if (set_mode != mode)
                      if (set_mode != mode)
                        {
                        {
                          /* We found a matching expression in the
                          /* We found a matching expression in the
                             wrong mode, but we don't have room to
                             wrong mode, but we don't have room to
                             store it in the array.  Punt.  This case
                             store it in the array.  Punt.  This case
                             should be rare.  */
                             should be rare.  */
                          break;
                          break;
                        }
                        }
                      /* INSN sets CC_REG to a value equal to CC_SRC
                      /* INSN sets CC_REG to a value equal to CC_SRC
                         with the right mode.  We can simply delete
                         with the right mode.  We can simply delete
                         it.  */
                         it.  */
                      delete_insn (insn);
                      delete_insn (insn);
                    }
                    }
 
 
                  /* We found an instruction to delete.  Keep looking,
                  /* We found an instruction to delete.  Keep looking,
                     in the hopes of finding a three-way jump.  */
                     in the hopes of finding a three-way jump.  */
                  continue;
                  continue;
                }
                }
 
 
              /* We found an instruction which sets the condition
              /* We found an instruction which sets the condition
                 code, so don't look any farther.  */
                 code, so don't look any farther.  */
              break;
              break;
            }
            }
 
 
          /* If INSN sets CC_REG in some other way, don't look any
          /* If INSN sets CC_REG in some other way, don't look any
             farther.  */
             farther.  */
          if (reg_set_p (cc_reg, insn))
          if (reg_set_p (cc_reg, insn))
            break;
            break;
        }
        }
 
 
      /* If we fell off the bottom of the block, we can keep looking
      /* If we fell off the bottom of the block, we can keep looking
         through successors.  We pass CAN_CHANGE_MODE as false because
         through successors.  We pass CAN_CHANGE_MODE as false because
         we aren't prepared to handle compatibility between the
         we aren't prepared to handle compatibility between the
         further blocks and this block.  */
         further blocks and this block.  */
      if (insn == end)
      if (insn == end)
        {
        {
          enum machine_mode submode;
          enum machine_mode submode;
 
 
          submode = cse_cc_succs (e->dest, cc_reg, cc_src, false);
          submode = cse_cc_succs (e->dest, cc_reg, cc_src, false);
          if (submode != VOIDmode)
          if (submode != VOIDmode)
            {
            {
              gcc_assert (submode == mode);
              gcc_assert (submode == mode);
              found_equiv = true;
              found_equiv = true;
              can_change_mode = false;
              can_change_mode = false;
            }
            }
        }
        }
    }
    }
 
 
  if (! found_equiv)
  if (! found_equiv)
    return VOIDmode;
    return VOIDmode;
 
 
  /* Now INSN_COUNT is the number of instructions we found which set
  /* Now INSN_COUNT is the number of instructions we found which set
     CC_REG to a value equivalent to CC_SRC.  The instructions are in
     CC_REG to a value equivalent to CC_SRC.  The instructions are in
     INSNS.  The modes used by those instructions are in MODES.  */
     INSNS.  The modes used by those instructions are in MODES.  */
 
 
  newreg = NULL_RTX;
  newreg = NULL_RTX;
  for (i = 0; i < insn_count; ++i)
  for (i = 0; i < insn_count; ++i)
    {
    {
      if (modes[i] != mode)
      if (modes[i] != mode)
        {
        {
          /* We need to change the mode of CC_REG in INSNS[i] and
          /* We need to change the mode of CC_REG in INSNS[i] and
             subsequent instructions.  */
             subsequent instructions.  */
          if (! newreg)
          if (! newreg)
            {
            {
              if (GET_MODE (cc_reg) == mode)
              if (GET_MODE (cc_reg) == mode)
                newreg = cc_reg;
                newreg = cc_reg;
              else
              else
                newreg = gen_rtx_REG (mode, REGNO (cc_reg));
                newreg = gen_rtx_REG (mode, REGNO (cc_reg));
            }
            }
          cse_change_cc_mode_insns (NEXT_INSN (insns[i]), last_insns[i],
          cse_change_cc_mode_insns (NEXT_INSN (insns[i]), last_insns[i],
                                    newreg);
                                    newreg);
        }
        }
 
 
      delete_insn (insns[i]);
      delete_insn (insns[i]);
    }
    }
 
 
  return mode;
  return mode;
}
}
 
 
/* If we have a fixed condition code register (or two), walk through
/* If we have a fixed condition code register (or two), walk through
   the instructions and try to eliminate duplicate assignments.  */
   the instructions and try to eliminate duplicate assignments.  */
 
 
static void
static void
cse_condition_code_reg (void)
cse_condition_code_reg (void)
{
{
  unsigned int cc_regno_1;
  unsigned int cc_regno_1;
  unsigned int cc_regno_2;
  unsigned int cc_regno_2;
  rtx cc_reg_1;
  rtx cc_reg_1;
  rtx cc_reg_2;
  rtx cc_reg_2;
  basic_block bb;
  basic_block bb;
 
 
  if (! targetm.fixed_condition_code_regs (&cc_regno_1, &cc_regno_2))
  if (! targetm.fixed_condition_code_regs (&cc_regno_1, &cc_regno_2))
    return;
    return;
 
 
  cc_reg_1 = gen_rtx_REG (CCmode, cc_regno_1);
  cc_reg_1 = gen_rtx_REG (CCmode, cc_regno_1);
  if (cc_regno_2 != INVALID_REGNUM)
  if (cc_regno_2 != INVALID_REGNUM)
    cc_reg_2 = gen_rtx_REG (CCmode, cc_regno_2);
    cc_reg_2 = gen_rtx_REG (CCmode, cc_regno_2);
  else
  else
    cc_reg_2 = NULL_RTX;
    cc_reg_2 = NULL_RTX;
 
 
  FOR_EACH_BB (bb)
  FOR_EACH_BB (bb)
    {
    {
      rtx last_insn;
      rtx last_insn;
      rtx cc_reg;
      rtx cc_reg;
      rtx insn;
      rtx insn;
      rtx cc_src_insn;
      rtx cc_src_insn;
      rtx cc_src;
      rtx cc_src;
      enum machine_mode mode;
      enum machine_mode mode;
      enum machine_mode orig_mode;
      enum machine_mode orig_mode;
 
 
      /* Look for blocks which end with a conditional jump based on a
      /* Look for blocks which end with a conditional jump based on a
         condition code register.  Then look for the instruction which
         condition code register.  Then look for the instruction which
         sets the condition code register.  Then look through the
         sets the condition code register.  Then look through the
         successor blocks for instructions which set the condition
         successor blocks for instructions which set the condition
         code register to the same value.  There are other possible
         code register to the same value.  There are other possible
         uses of the condition code register, but these are by far the
         uses of the condition code register, but these are by far the
         most common and the ones which we are most likely to be able
         most common and the ones which we are most likely to be able
         to optimize.  */
         to optimize.  */
 
 
      last_insn = BB_END (bb);
      last_insn = BB_END (bb);
      if (!JUMP_P (last_insn))
      if (!JUMP_P (last_insn))
        continue;
        continue;
 
 
      if (reg_referenced_p (cc_reg_1, PATTERN (last_insn)))
      if (reg_referenced_p (cc_reg_1, PATTERN (last_insn)))
        cc_reg = cc_reg_1;
        cc_reg = cc_reg_1;
      else if (cc_reg_2 && reg_referenced_p (cc_reg_2, PATTERN (last_insn)))
      else if (cc_reg_2 && reg_referenced_p (cc_reg_2, PATTERN (last_insn)))
        cc_reg = cc_reg_2;
        cc_reg = cc_reg_2;
      else
      else
        continue;
        continue;
 
 
      cc_src_insn = NULL_RTX;
      cc_src_insn = NULL_RTX;
      cc_src = NULL_RTX;
      cc_src = NULL_RTX;
      for (insn = PREV_INSN (last_insn);
      for (insn = PREV_INSN (last_insn);
           insn && insn != PREV_INSN (BB_HEAD (bb));
           insn && insn != PREV_INSN (BB_HEAD (bb));
           insn = PREV_INSN (insn))
           insn = PREV_INSN (insn))
        {
        {
          rtx set;
          rtx set;
 
 
          if (! INSN_P (insn))
          if (! INSN_P (insn))
            continue;
            continue;
          set = single_set (insn);
          set = single_set (insn);
          if (set
          if (set
              && REG_P (SET_DEST (set))
              && REG_P (SET_DEST (set))
              && REGNO (SET_DEST (set)) == REGNO (cc_reg))
              && REGNO (SET_DEST (set)) == REGNO (cc_reg))
            {
            {
              cc_src_insn = insn;
              cc_src_insn = insn;
              cc_src = SET_SRC (set);
              cc_src = SET_SRC (set);
              break;
              break;
            }
            }
          else if (reg_set_p (cc_reg, insn))
          else if (reg_set_p (cc_reg, insn))
            break;
            break;
        }
        }
 
 
      if (! cc_src_insn)
      if (! cc_src_insn)
        continue;
        continue;
 
 
      if (modified_between_p (cc_src, cc_src_insn, NEXT_INSN (last_insn)))
      if (modified_between_p (cc_src, cc_src_insn, NEXT_INSN (last_insn)))
        continue;
        continue;
 
 
      /* Now CC_REG is a condition code register used for a
      /* Now CC_REG is a condition code register used for a
         conditional jump at the end of the block, and CC_SRC, in
         conditional jump at the end of the block, and CC_SRC, in
         CC_SRC_INSN, is the value to which that condition code
         CC_SRC_INSN, is the value to which that condition code
         register is set, and CC_SRC is still meaningful at the end of
         register is set, and CC_SRC is still meaningful at the end of
         the basic block.  */
         the basic block.  */
 
 
      orig_mode = GET_MODE (cc_src);
      orig_mode = GET_MODE (cc_src);
      mode = cse_cc_succs (bb, cc_reg, cc_src, true);
      mode = cse_cc_succs (bb, cc_reg, cc_src, true);
      if (mode != VOIDmode)
      if (mode != VOIDmode)
        {
        {
          gcc_assert (mode == GET_MODE (cc_src));
          gcc_assert (mode == GET_MODE (cc_src));
          if (mode != orig_mode)
          if (mode != orig_mode)
            {
            {
              rtx newreg = gen_rtx_REG (mode, REGNO (cc_reg));
              rtx newreg = gen_rtx_REG (mode, REGNO (cc_reg));
 
 
              cse_change_cc_mode_insn (cc_src_insn, newreg);
              cse_change_cc_mode_insn (cc_src_insn, newreg);
 
 
              /* Do the same in the following insns that use the
              /* Do the same in the following insns that use the
                 current value of CC_REG within BB.  */
                 current value of CC_REG within BB.  */
              cse_change_cc_mode_insns (NEXT_INSN (cc_src_insn),
              cse_change_cc_mode_insns (NEXT_INSN (cc_src_insn),
                                        NEXT_INSN (last_insn),
                                        NEXT_INSN (last_insn),
                                        newreg);
                                        newreg);
            }
            }
        }
        }
    }
    }
}
}


 
 
/* Perform common subexpression elimination.  Nonzero value from
/* Perform common subexpression elimination.  Nonzero value from
   `cse_main' means that jumps were simplified and some code may now
   `cse_main' means that jumps were simplified and some code may now
   be unreachable, so do jump optimization again.  */
   be unreachable, so do jump optimization again.  */
static bool
static bool
gate_handle_cse (void)
gate_handle_cse (void)
{
{
  return optimize > 0;
  return optimize > 0;
}
}
 
 
static unsigned int
static unsigned int
rest_of_handle_cse (void)
rest_of_handle_cse (void)
{
{
  int tem;
  int tem;
 
 
  if (dump_file)
  if (dump_file)
    dump_flow_info (dump_file, dump_flags);
    dump_flow_info (dump_file, dump_flags);
 
 
  reg_scan (get_insns (), max_reg_num ());
  reg_scan (get_insns (), max_reg_num ());
 
 
  tem = cse_main (get_insns (), max_reg_num ());
  tem = cse_main (get_insns (), max_reg_num ());
  if (tem)
  if (tem)
    rebuild_jump_labels (get_insns ());
    rebuild_jump_labels (get_insns ());
  if (purge_all_dead_edges ())
  if (purge_all_dead_edges ())
    delete_unreachable_blocks ();
    delete_unreachable_blocks ();
 
 
  delete_trivially_dead_insns (get_insns (), max_reg_num ());
  delete_trivially_dead_insns (get_insns (), max_reg_num ());
 
 
  /* If we are not running more CSE passes, then we are no longer
  /* If we are not running more CSE passes, then we are no longer
     expecting CSE to be run.  But always rerun it in a cheap mode.  */
     expecting CSE to be run.  But always rerun it in a cheap mode.  */
  cse_not_expected = !flag_rerun_cse_after_loop && !flag_gcse;
  cse_not_expected = !flag_rerun_cse_after_loop && !flag_gcse;
 
 
  if (tem)
  if (tem)
    delete_dead_jumptables ();
    delete_dead_jumptables ();
 
 
  if (tem || optimize > 1)
  if (tem || optimize > 1)
    cleanup_cfg (CLEANUP_EXPENSIVE);
    cleanup_cfg (CLEANUP_EXPENSIVE);
  return 0;
  return 0;
}
}
 
 
struct tree_opt_pass pass_cse =
struct tree_opt_pass pass_cse =
{
{
  "cse1",                               /* name */
  "cse1",                               /* name */
  gate_handle_cse,                      /* gate */
  gate_handle_cse,                      /* gate */
  rest_of_handle_cse,                   /* execute */
  rest_of_handle_cse,                   /* execute */
  NULL,                                 /* sub */
  NULL,                                 /* sub */
  NULL,                                 /* next */
  NULL,                                 /* next */
  0,                                    /* static_pass_number */
  0,                                    /* static_pass_number */
  TV_CSE,                               /* tv_id */
  TV_CSE,                               /* tv_id */
  0,                                    /* properties_required */
  0,                                    /* properties_required */
  0,                                    /* properties_provided */
  0,                                    /* properties_provided */
  0,                                    /* properties_destroyed */
  0,                                    /* properties_destroyed */
  0,                                    /* todo_flags_start */
  0,                                    /* todo_flags_start */
  TODO_dump_func |
  TODO_dump_func |
  TODO_ggc_collect,                     /* todo_flags_finish */
  TODO_ggc_collect,                     /* todo_flags_finish */
  's'                                   /* letter */
  's'                                   /* letter */
};
};
 
 
 
 
static bool
static bool
gate_handle_cse2 (void)
gate_handle_cse2 (void)
{
{
  return optimize > 0 && flag_rerun_cse_after_loop;
  return optimize > 0 && flag_rerun_cse_after_loop;
}
}
 
 
/* Run second CSE pass after loop optimizations.  */
/* Run second CSE pass after loop optimizations.  */
static unsigned int
static unsigned int
rest_of_handle_cse2 (void)
rest_of_handle_cse2 (void)
{
{
  int tem;
  int tem;
 
 
  if (dump_file)
  if (dump_file)
    dump_flow_info (dump_file, dump_flags);
    dump_flow_info (dump_file, dump_flags);
 
 
  tem = cse_main (get_insns (), max_reg_num ());
  tem = cse_main (get_insns (), max_reg_num ());
 
 
  /* Run a pass to eliminate duplicated assignments to condition code
  /* Run a pass to eliminate duplicated assignments to condition code
     registers.  We have to run this after bypass_jumps, because it
     registers.  We have to run this after bypass_jumps, because it
     makes it harder for that pass to determine whether a jump can be
     makes it harder for that pass to determine whether a jump can be
     bypassed safely.  */
     bypassed safely.  */
  cse_condition_code_reg ();
  cse_condition_code_reg ();
 
 
  purge_all_dead_edges ();
  purge_all_dead_edges ();
  delete_trivially_dead_insns (get_insns (), max_reg_num ());
  delete_trivially_dead_insns (get_insns (), max_reg_num ());
 
 
  if (tem)
  if (tem)
    {
    {
      timevar_push (TV_JUMP);
      timevar_push (TV_JUMP);
      rebuild_jump_labels (get_insns ());
      rebuild_jump_labels (get_insns ());
      delete_dead_jumptables ();
      delete_dead_jumptables ();
      cleanup_cfg (CLEANUP_EXPENSIVE);
      cleanup_cfg (CLEANUP_EXPENSIVE);
      timevar_pop (TV_JUMP);
      timevar_pop (TV_JUMP);
    }
    }
  reg_scan (get_insns (), max_reg_num ());
  reg_scan (get_insns (), max_reg_num ());
  cse_not_expected = 1;
  cse_not_expected = 1;
  return 0;
  return 0;
}
}
 
 
 
 
struct tree_opt_pass pass_cse2 =
struct tree_opt_pass pass_cse2 =
{
{
  "cse2",                               /* name */
  "cse2",                               /* name */
  gate_handle_cse2,                     /* gate */
  gate_handle_cse2,                     /* gate */
  rest_of_handle_cse2,                  /* execute */
  rest_of_handle_cse2,                  /* execute */
  NULL,                                 /* sub */
  NULL,                                 /* sub */
  NULL,                                 /* next */
  NULL,                                 /* next */
  0,                                    /* static_pass_number */
  0,                                    /* static_pass_number */
  TV_CSE2,                              /* tv_id */
  TV_CSE2,                              /* tv_id */
  0,                                    /* properties_required */
  0,                                    /* properties_required */
  0,                                    /* properties_provided */
  0,                                    /* properties_provided */
  0,                                    /* properties_destroyed */
  0,                                    /* properties_destroyed */
  0,                                    /* todo_flags_start */
  0,                                    /* todo_flags_start */
  TODO_dump_func |
  TODO_dump_func |
  TODO_ggc_collect,                     /* todo_flags_finish */
  TODO_ggc_collect,                     /* todo_flags_finish */
  't'                                   /* letter */
  't'                                   /* letter */
};
};
 
 
 
 

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