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/* SSA-PRE for trees.
/* SSA-PRE for trees.
   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007
   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007
   Free Software Foundation, Inc.
   Free Software Foundation, Inc.
   Contributed by Daniel Berlin <dan@dberlin.org> and Steven Bosscher
   Contributed by Daniel Berlin <dan@dberlin.org> and Steven Bosscher
   <stevenb@suse.de>
   <stevenb@suse.de>
 
 
This file is part of GCC.
This file is part of GCC.
 
 
GCC is free software; you can redistribute it and/or modify
GCC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
the Free Software Foundation; either version 3, or (at your option)
any later version.
any later version.
 
 
GCC is distributed in the hope that it will be useful,
GCC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
GNU General Public License 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"
#include "system.h"
#include "system.h"
#include "coretypes.h"
#include "coretypes.h"
#include "tm.h"
#include "tm.h"
#include "ggc.h"
#include "ggc.h"
#include "tree.h"
#include "tree.h"
#include "basic-block.h"
#include "basic-block.h"
#include "diagnostic.h"
#include "diagnostic.h"
#include "tree-inline.h"
#include "tree-inline.h"
#include "tree-flow.h"
#include "tree-flow.h"
#include "tree-gimple.h"
#include "tree-gimple.h"
#include "tree-dump.h"
#include "tree-dump.h"
#include "timevar.h"
#include "timevar.h"
#include "fibheap.h"
#include "fibheap.h"
#include "hashtab.h"
#include "hashtab.h"
#include "tree-iterator.h"
#include "tree-iterator.h"
#include "real.h"
#include "real.h"
#include "alloc-pool.h"
#include "alloc-pool.h"
#include "tree-pass.h"
#include "tree-pass.h"
#include "flags.h"
#include "flags.h"
#include "bitmap.h"
#include "bitmap.h"
#include "langhooks.h"
#include "langhooks.h"
#include "cfgloop.h"
#include "cfgloop.h"
 
 
/* TODO:
/* TODO:
 
 
   1. Avail sets can be shared by making an avail_find_leader that
   1. Avail sets can be shared by making an avail_find_leader that
      walks up the dominator tree and looks in those avail sets.
      walks up the dominator tree and looks in those avail sets.
      This might affect code optimality, it's unclear right now.
      This might affect code optimality, it's unclear right now.
   2. Strength reduction can be performed by anticipating expressions
   2. Strength reduction can be performed by anticipating expressions
      we can repair later on.
      we can repair later on.
   3. We can do back-substitution or smarter value numbering to catch
   3. We can do back-substitution or smarter value numbering to catch
      commutative expressions split up over multiple statements.
      commutative expressions split up over multiple statements.
   4. ANTIC_SAFE_LOADS could be a lot smarter than it is now.
   4. ANTIC_SAFE_LOADS could be a lot smarter than it is now.
      Right now, it is simply calculating loads that occur before
      Right now, it is simply calculating loads that occur before
      any store in a block, instead of loads that occur before
      any store in a block, instead of loads that occur before
      stores that affect them.  This is relatively more expensive, and
      stores that affect them.  This is relatively more expensive, and
      it's not clear how much more it will buy us.
      it's not clear how much more it will buy us.
*/
*/
 
 
/* For ease of terminology, "expression node" in the below refers to
/* For ease of terminology, "expression node" in the below refers to
   every expression node but MODIFY_EXPR, because MODIFY_EXPR's represent
   every expression node but MODIFY_EXPR, because MODIFY_EXPR's represent
   the actual statement containing the expressions we care about, and
   the actual statement containing the expressions we care about, and
   we cache the value number by putting it in the expression.  */
   we cache the value number by putting it in the expression.  */
 
 
/* Basic algorithm
/* Basic algorithm
 
 
   First we walk the statements to generate the AVAIL sets, the
   First we walk the statements to generate the AVAIL sets, the
   EXP_GEN sets, and the tmp_gen sets.  EXP_GEN sets represent the
   EXP_GEN sets, and the tmp_gen sets.  EXP_GEN sets represent the
   generation of values/expressions by a given block.  We use them
   generation of values/expressions by a given block.  We use them
   when computing the ANTIC sets.  The AVAIL sets consist of
   when computing the ANTIC sets.  The AVAIL sets consist of
   SSA_NAME's that represent values, so we know what values are
   SSA_NAME's that represent values, so we know what values are
   available in what blocks.  AVAIL is a forward dataflow problem.  In
   available in what blocks.  AVAIL is a forward dataflow problem.  In
   SSA, values are never killed, so we don't need a kill set, or a
   SSA, values are never killed, so we don't need a kill set, or a
   fixpoint iteration, in order to calculate the AVAIL sets.  In
   fixpoint iteration, in order to calculate the AVAIL sets.  In
   traditional parlance, AVAIL sets tell us the downsafety of the
   traditional parlance, AVAIL sets tell us the downsafety of the
   expressions/values.
   expressions/values.
 
 
   Next, we generate the ANTIC sets.  These sets represent the
   Next, we generate the ANTIC sets.  These sets represent the
   anticipatable expressions.  ANTIC is a backwards dataflow
   anticipatable expressions.  ANTIC is a backwards dataflow
   problem.An expression is anticipatable in a given block if it could
   problem.An expression is anticipatable in a given block if it could
   be generated in that block.  This means that if we had to perform
   be generated in that block.  This means that if we had to perform
   an insertion in that block, of the value of that expression, we
   an insertion in that block, of the value of that expression, we
   could.  Calculating the ANTIC sets requires phi translation of
   could.  Calculating the ANTIC sets requires phi translation of
   expressions, because the flow goes backwards through phis.  We must
   expressions, because the flow goes backwards through phis.  We must
   iterate to a fixpoint of the ANTIC sets, because we have a kill
   iterate to a fixpoint of the ANTIC sets, because we have a kill
   set.  Even in SSA form, values are not live over the entire
   set.  Even in SSA form, values are not live over the entire
   function, only from their definition point onwards.  So we have to
   function, only from their definition point onwards.  So we have to
   remove values from the ANTIC set once we go past the definition
   remove values from the ANTIC set once we go past the definition
   point of the leaders that make them up.
   point of the leaders that make them up.
   compute_antic/compute_antic_aux performs this computation.
   compute_antic/compute_antic_aux performs this computation.
 
 
   Third, we perform insertions to make partially redundant
   Third, we perform insertions to make partially redundant
   expressions fully redundant.
   expressions fully redundant.
 
 
   An expression is partially redundant (excluding partial
   An expression is partially redundant (excluding partial
   anticipation) if:
   anticipation) if:
 
 
   1. It is AVAIL in some, but not all, of the predecessors of a
   1. It is AVAIL in some, but not all, of the predecessors of a
      given block.
      given block.
   2. It is ANTIC in all the predecessors.
   2. It is ANTIC in all the predecessors.
 
 
   In order to make it fully redundant, we insert the expression into
   In order to make it fully redundant, we insert the expression into
   the predecessors where it is not available, but is ANTIC.
   the predecessors where it is not available, but is ANTIC.
   insert/insert_aux performs this insertion.
   insert/insert_aux performs this insertion.
 
 
   Fourth, we eliminate fully redundant expressions.
   Fourth, we eliminate fully redundant expressions.
   This is a simple statement walk that replaces redundant
   This is a simple statement walk that replaces redundant
   calculations  with the now available values.  */
   calculations  with the now available values.  */
 
 
/* Representations of value numbers:
/* Representations of value numbers:
 
 
   Value numbers are represented using the "value handle" approach.
   Value numbers are represented using the "value handle" approach.
   This means that each SSA_NAME (and for other reasons to be
   This means that each SSA_NAME (and for other reasons to be
   disclosed in a moment, expression nodes) has a value handle that
   disclosed in a moment, expression nodes) has a value handle that
   can be retrieved through get_value_handle.  This value handle, *is*
   can be retrieved through get_value_handle.  This value handle, *is*
   the value number of the SSA_NAME.  You can pointer compare the
   the value number of the SSA_NAME.  You can pointer compare the
   value handles for equivalence purposes.
   value handles for equivalence purposes.
 
 
   For debugging reasons, the value handle is internally more than
   For debugging reasons, the value handle is internally more than
   just a number, it is a VAR_DECL named "value.x", where x is a
   just a number, it is a VAR_DECL named "value.x", where x is a
   unique number for each value number in use.  This allows
   unique number for each value number in use.  This allows
   expressions with SSA_NAMES replaced by value handles to still be
   expressions with SSA_NAMES replaced by value handles to still be
   pretty printed in a sane way.  They simply print as "value.3 *
   pretty printed in a sane way.  They simply print as "value.3 *
   value.5", etc.
   value.5", etc.
 
 
   Expression nodes have value handles associated with them as a
   Expression nodes have value handles associated with them as a
   cache.  Otherwise, we'd have to look them up again in the hash
   cache.  Otherwise, we'd have to look them up again in the hash
   table This makes significant difference (factor of two or more) on
   table This makes significant difference (factor of two or more) on
   some test cases.  They can be thrown away after the pass is
   some test cases.  They can be thrown away after the pass is
   finished.  */
   finished.  */
 
 
/* Representation of expressions on value numbers:
/* Representation of expressions on value numbers:
 
 
   In some portions of this code, you will notice we allocate "fake"
   In some portions of this code, you will notice we allocate "fake"
   analogues to the expression we are value numbering, and replace the
   analogues to the expression we are value numbering, and replace the
   operands with the values of the expression.  Since we work on
   operands with the values of the expression.  Since we work on
   values, and not just names, we canonicalize expressions to value
   values, and not just names, we canonicalize expressions to value
   expressions for use in the ANTIC sets, the EXP_GEN set, etc.
   expressions for use in the ANTIC sets, the EXP_GEN set, etc.
 
 
   This is theoretically unnecessary, it just saves a bunch of
   This is theoretically unnecessary, it just saves a bunch of
   repeated get_value_handle and find_leader calls in the remainder of
   repeated get_value_handle and find_leader calls in the remainder of
   the code, trading off temporary memory usage for speed.  The tree
   the code, trading off temporary memory usage for speed.  The tree
   nodes aren't actually creating more garbage, since they are
   nodes aren't actually creating more garbage, since they are
   allocated in a special pools which are thrown away at the end of
   allocated in a special pools which are thrown away at the end of
   this pass.
   this pass.
 
 
   All of this also means that if you print the EXP_GEN or ANTIC sets,
   All of this also means that if you print the EXP_GEN or ANTIC sets,
   you will see "value.5 + value.7" in the set, instead of "a_55 +
   you will see "value.5 + value.7" in the set, instead of "a_55 +
   b_66" or something.  The only thing that actually cares about
   b_66" or something.  The only thing that actually cares about
   seeing the value leaders is phi translation, and it needs to be
   seeing the value leaders is phi translation, and it needs to be
   able to find the leader for a value in an arbitrary block, so this
   able to find the leader for a value in an arbitrary block, so this
   "value expression" form is perfect for it (otherwise you'd do
   "value expression" form is perfect for it (otherwise you'd do
   get_value_handle->find_leader->translate->get_value_handle->find_leader).*/
   get_value_handle->find_leader->translate->get_value_handle->find_leader).*/
 
 
 
 
/* Representation of sets:
/* Representation of sets:
 
 
   There are currently two types of sets used, hopefully to be unified soon.
   There are currently two types of sets used, hopefully to be unified soon.
   The AVAIL sets do not need to be sorted in any particular order,
   The AVAIL sets do not need to be sorted in any particular order,
   and thus, are simply represented as two bitmaps, one that keeps
   and thus, are simply represented as two bitmaps, one that keeps
   track of values present in the set, and one that keeps track of
   track of values present in the set, and one that keeps track of
   expressions present in the set.
   expressions present in the set.
 
 
   The other sets are represented as doubly linked lists kept in topological
   The other sets are represented as doubly linked lists kept in topological
   order, with an optional supporting bitmap of values present in the
   order, with an optional supporting bitmap of values present in the
   set.  The sets represent values, and the elements can be values or
   set.  The sets represent values, and the elements can be values or
   expressions.  The elements can appear in different sets, but each
   expressions.  The elements can appear in different sets, but each
   element can only appear once in each set.
   element can only appear once in each set.
 
 
   Since each node in the set represents a value, we also want to be
   Since each node in the set represents a value, we also want to be
   able to map expression, set pairs to something that tells us
   able to map expression, set pairs to something that tells us
   whether the value is present is a set.  We use a per-set bitmap for
   whether the value is present is a set.  We use a per-set bitmap for
   that.  The value handles also point to a linked list of the
   that.  The value handles also point to a linked list of the
   expressions they represent via a tree annotation.  This is mainly
   expressions they represent via a tree annotation.  This is mainly
   useful only for debugging, since we don't do identity lookups.  */
   useful only for debugging, since we don't do identity lookups.  */
 
 
 
 
static bool in_fre = false;
static bool in_fre = false;
 
 
/* A value set element.  Basically a single linked list of
/* A value set element.  Basically a single linked list of
   expressions/values.  */
   expressions/values.  */
typedef struct value_set_node
typedef struct value_set_node
{
{
  /* An expression.  */
  /* An expression.  */
  tree expr;
  tree expr;
 
 
  /* A pointer to the next element of the value set.  */
  /* A pointer to the next element of the value set.  */
  struct value_set_node *next;
  struct value_set_node *next;
} *value_set_node_t;
} *value_set_node_t;
 
 
 
 
/* A value set.  This is a singly linked list of value_set_node
/* A value set.  This is a singly linked list of value_set_node
   elements with a possible bitmap that tells us what values exist in
   elements with a possible bitmap that tells us what values exist in
   the set.  This set must be kept in topologically sorted order.  */
   the set.  This set must be kept in topologically sorted order.  */
typedef struct value_set
typedef struct value_set
{
{
  /* The head of the list.  Used for iterating over the list in
  /* The head of the list.  Used for iterating over the list in
     order.  */
     order.  */
  value_set_node_t head;
  value_set_node_t head;
 
 
  /* The tail of the list.  Used for tail insertions, which are
  /* The tail of the list.  Used for tail insertions, which are
     necessary to keep the set in topologically sorted order because
     necessary to keep the set in topologically sorted order because
     of how the set is built.  */
     of how the set is built.  */
  value_set_node_t tail;
  value_set_node_t tail;
 
 
  /* The length of the list.  */
  /* The length of the list.  */
  size_t length;
  size_t length;
 
 
  /* True if the set is indexed, which means it contains a backing
  /* True if the set is indexed, which means it contains a backing
     bitmap for quick determination of whether certain values exist in the
     bitmap for quick determination of whether certain values exist in the
     set.  */
     set.  */
  bool indexed;
  bool indexed;
 
 
  /* The bitmap of values that exist in the set.  May be NULL in an
  /* The bitmap of values that exist in the set.  May be NULL in an
     empty or non-indexed set.  */
     empty or non-indexed set.  */
  bitmap values;
  bitmap values;
 
 
} *value_set_t;
} *value_set_t;
 
 
 
 
/* An unordered bitmap set.  One bitmap tracks values, the other,
/* An unordered bitmap set.  One bitmap tracks values, the other,
   expressions.  */
   expressions.  */
typedef struct bitmap_set
typedef struct bitmap_set
{
{
  bitmap expressions;
  bitmap expressions;
  bitmap values;
  bitmap values;
} *bitmap_set_t;
} *bitmap_set_t;
 
 
/* Sets that we need to keep track of.  */
/* Sets that we need to keep track of.  */
typedef struct bb_value_sets
typedef struct bb_value_sets
{
{
  /* The EXP_GEN set, which represents expressions/values generated in
  /* The EXP_GEN set, which represents expressions/values generated in
     a basic block.  */
     a basic block.  */
  value_set_t exp_gen;
  value_set_t exp_gen;
 
 
  /* The PHI_GEN set, which represents PHI results generated in a
  /* The PHI_GEN set, which represents PHI results generated in a
     basic block.  */
     basic block.  */
  bitmap_set_t phi_gen;
  bitmap_set_t phi_gen;
 
 
  /* The TMP_GEN set, which represents results/temporaries generated
  /* The TMP_GEN set, which represents results/temporaries generated
     in a basic block. IE the LHS of an expression.  */
     in a basic block. IE the LHS of an expression.  */
  bitmap_set_t tmp_gen;
  bitmap_set_t tmp_gen;
 
 
  /* The AVAIL_OUT set, which represents which values are available in
  /* The AVAIL_OUT set, which represents which values are available in
     a given basic block.  */
     a given basic block.  */
  bitmap_set_t avail_out;
  bitmap_set_t avail_out;
 
 
  /* The ANTIC_IN set, which represents which values are anticipatable
  /* The ANTIC_IN set, which represents which values are anticipatable
     in a given basic block.  */
     in a given basic block.  */
  value_set_t antic_in;
  value_set_t antic_in;
 
 
  /* The NEW_SETS set, which is used during insertion to augment the
  /* The NEW_SETS set, which is used during insertion to augment the
     AVAIL_OUT set of blocks with the new insertions performed during
     AVAIL_OUT set of blocks with the new insertions performed during
     the current iteration.  */
     the current iteration.  */
  bitmap_set_t new_sets;
  bitmap_set_t new_sets;
 
 
  /* The RVUSE sets, which are used during ANTIC computation to ensure
  /* The RVUSE sets, which are used during ANTIC computation to ensure
     that we don't mark loads ANTIC once they have died.  */
     that we don't mark loads ANTIC once they have died.  */
  bitmap rvuse_in;
  bitmap rvuse_in;
  bitmap rvuse_out;
  bitmap rvuse_out;
  bitmap rvuse_gen;
  bitmap rvuse_gen;
  bitmap rvuse_kill;
  bitmap rvuse_kill;
 
 
  /* For actually occurring loads, as long as they occur before all the
  /* For actually occurring loads, as long as they occur before all the
     other stores in the block, we know they are antic at the top of
     other stores in the block, we know they are antic at the top of
     the block, regardless of RVUSE_KILL.  */
     the block, regardless of RVUSE_KILL.  */
  value_set_t antic_safe_loads;
  value_set_t antic_safe_loads;
} *bb_value_sets_t;
} *bb_value_sets_t;
 
 
#define EXP_GEN(BB)     ((bb_value_sets_t) ((BB)->aux))->exp_gen
#define EXP_GEN(BB)     ((bb_value_sets_t) ((BB)->aux))->exp_gen
#define PHI_GEN(BB)     ((bb_value_sets_t) ((BB)->aux))->phi_gen
#define PHI_GEN(BB)     ((bb_value_sets_t) ((BB)->aux))->phi_gen
#define TMP_GEN(BB)     ((bb_value_sets_t) ((BB)->aux))->tmp_gen
#define TMP_GEN(BB)     ((bb_value_sets_t) ((BB)->aux))->tmp_gen
#define AVAIL_OUT(BB)   ((bb_value_sets_t) ((BB)->aux))->avail_out
#define AVAIL_OUT(BB)   ((bb_value_sets_t) ((BB)->aux))->avail_out
#define ANTIC_IN(BB)    ((bb_value_sets_t) ((BB)->aux))->antic_in
#define ANTIC_IN(BB)    ((bb_value_sets_t) ((BB)->aux))->antic_in
#define RVUSE_IN(BB)    ((bb_value_sets_t) ((BB)->aux))->rvuse_in
#define RVUSE_IN(BB)    ((bb_value_sets_t) ((BB)->aux))->rvuse_in
#define RVUSE_GEN(BB)   ((bb_value_sets_t) ((BB)->aux))->rvuse_gen
#define RVUSE_GEN(BB)   ((bb_value_sets_t) ((BB)->aux))->rvuse_gen
#define RVUSE_KILL(BB)   ((bb_value_sets_t) ((BB)->aux))->rvuse_kill
#define RVUSE_KILL(BB)   ((bb_value_sets_t) ((BB)->aux))->rvuse_kill
#define RVUSE_OUT(BB)    ((bb_value_sets_t) ((BB)->aux))->rvuse_out
#define RVUSE_OUT(BB)    ((bb_value_sets_t) ((BB)->aux))->rvuse_out
#define NEW_SETS(BB)    ((bb_value_sets_t) ((BB)->aux))->new_sets
#define NEW_SETS(BB)    ((bb_value_sets_t) ((BB)->aux))->new_sets
#define ANTIC_SAFE_LOADS(BB) ((bb_value_sets_t) ((BB)->aux))->antic_safe_loads
#define ANTIC_SAFE_LOADS(BB) ((bb_value_sets_t) ((BB)->aux))->antic_safe_loads
 
 
/* This structure is used to keep track of statistics on what
/* This structure is used to keep track of statistics on what
   optimization PRE was able to perform.  */
   optimization PRE was able to perform.  */
static struct
static struct
{
{
  /* The number of RHS computations eliminated by PRE.  */
  /* The number of RHS computations eliminated by PRE.  */
  int eliminations;
  int eliminations;
 
 
  /* The number of new expressions/temporaries generated by PRE.  */
  /* The number of new expressions/temporaries generated by PRE.  */
  int insertions;
  int insertions;
 
 
  /* The number of new PHI nodes added by PRE.  */
  /* The number of new PHI nodes added by PRE.  */
  int phis;
  int phis;
 
 
  /* The number of values found constant.  */
  /* The number of values found constant.  */
  int constified;
  int constified;
 
 
} pre_stats;
} pre_stats;
 
 
 
 
static tree bitmap_find_leader (bitmap_set_t, tree);
static tree bitmap_find_leader (bitmap_set_t, tree);
static tree find_leader (value_set_t, tree);
static tree find_leader (value_set_t, tree);
static void value_insert_into_set (value_set_t, tree);
static void value_insert_into_set (value_set_t, tree);
static void bitmap_value_insert_into_set (bitmap_set_t, tree);
static void bitmap_value_insert_into_set (bitmap_set_t, tree);
static void bitmap_value_replace_in_set (bitmap_set_t, tree);
static void bitmap_value_replace_in_set (bitmap_set_t, tree);
static void insert_into_set (value_set_t, tree);
static void insert_into_set (value_set_t, tree);
static void bitmap_set_copy (bitmap_set_t, bitmap_set_t);
static void bitmap_set_copy (bitmap_set_t, bitmap_set_t);
static bool bitmap_set_contains_value (bitmap_set_t, tree);
static bool bitmap_set_contains_value (bitmap_set_t, tree);
static bitmap_set_t bitmap_set_new (void);
static bitmap_set_t bitmap_set_new (void);
static value_set_t set_new  (bool);
static value_set_t set_new  (bool);
static bool is_undefined_value (tree);
static bool is_undefined_value (tree);
static tree create_expression_by_pieces (basic_block, tree, tree);
static tree create_expression_by_pieces (basic_block, tree, tree);
static tree find_or_generate_expression (basic_block, tree, tree);
static tree find_or_generate_expression (basic_block, tree, tree);
 
 
 
 
/* We can add and remove elements and entries to and from sets
/* We can add and remove elements and entries to and from sets
   and hash tables, so we use alloc pools for them.  */
   and hash tables, so we use alloc pools for them.  */
 
 
static alloc_pool value_set_pool;
static alloc_pool value_set_pool;
static alloc_pool bitmap_set_pool;
static alloc_pool bitmap_set_pool;
static alloc_pool value_set_node_pool;
static alloc_pool value_set_node_pool;
static alloc_pool binary_node_pool;
static alloc_pool binary_node_pool;
static alloc_pool unary_node_pool;
static alloc_pool unary_node_pool;
static alloc_pool reference_node_pool;
static alloc_pool reference_node_pool;
static alloc_pool comparison_node_pool;
static alloc_pool comparison_node_pool;
static alloc_pool expression_node_pool;
static alloc_pool expression_node_pool;
static alloc_pool list_node_pool;
static alloc_pool list_node_pool;
static alloc_pool modify_expr_node_pool;
static alloc_pool modify_expr_node_pool;
static bitmap_obstack grand_bitmap_obstack;
static bitmap_obstack grand_bitmap_obstack;
 
 
/* To avoid adding 300 temporary variables when we only need one, we
/* To avoid adding 300 temporary variables when we only need one, we
   only create one temporary variable, on demand, and build ssa names
   only create one temporary variable, on demand, and build ssa names
   off that.  We do have to change the variable if the types don't
   off that.  We do have to change the variable if the types don't
   match the current variable's type.  */
   match the current variable's type.  */
static tree pretemp;
static tree pretemp;
static tree storetemp;
static tree storetemp;
static tree mergephitemp;
static tree mergephitemp;
static tree prephitemp;
static tree prephitemp;
 
 
/* Set of blocks with statements that have had its EH information
/* Set of blocks with statements that have had its EH information
   cleaned up.  */
   cleaned up.  */
static bitmap need_eh_cleanup;
static bitmap need_eh_cleanup;
 
 
/* The phi_translate_table caches phi translations for a given
/* The phi_translate_table caches phi translations for a given
   expression and predecessor.  */
   expression and predecessor.  */
 
 
static htab_t phi_translate_table;
static htab_t phi_translate_table;
 
 
/* A three tuple {e, pred, v} used to cache phi translations in the
/* A three tuple {e, pred, v} used to cache phi translations in the
   phi_translate_table.  */
   phi_translate_table.  */
 
 
typedef struct expr_pred_trans_d
typedef struct expr_pred_trans_d
{
{
  /* The expression.  */
  /* The expression.  */
  tree e;
  tree e;
 
 
  /* The predecessor block along which we translated the expression.  */
  /* The predecessor block along which we translated the expression.  */
  basic_block pred;
  basic_block pred;
 
 
  /* vuses associated with the expression.  */
  /* vuses associated with the expression.  */
  VEC (tree, gc) *vuses;
  VEC (tree, gc) *vuses;
 
 
  /* The value that resulted from the translation.  */
  /* The value that resulted from the translation.  */
  tree v;
  tree v;
 
 
 
 
  /* The hashcode for the expression, pred pair. This is cached for
  /* The hashcode for the expression, pred pair. This is cached for
     speed reasons.  */
     speed reasons.  */
  hashval_t hashcode;
  hashval_t hashcode;
} *expr_pred_trans_t;
} *expr_pred_trans_t;
 
 
/* Return the hash value for a phi translation table entry.  */
/* Return the hash value for a phi translation table entry.  */
 
 
static hashval_t
static hashval_t
expr_pred_trans_hash (const void *p)
expr_pred_trans_hash (const void *p)
{
{
  const expr_pred_trans_t ve = (expr_pred_trans_t) p;
  const expr_pred_trans_t ve = (expr_pred_trans_t) p;
  return ve->hashcode;
  return ve->hashcode;
}
}
 
 
/* Return true if two phi translation table entries are the same.
/* Return true if two phi translation table entries are the same.
   P1 and P2 should point to the expr_pred_trans_t's to be compared.*/
   P1 and P2 should point to the expr_pred_trans_t's to be compared.*/
 
 
static int
static int
expr_pred_trans_eq (const void *p1, const void *p2)
expr_pred_trans_eq (const void *p1, const void *p2)
{
{
  const expr_pred_trans_t ve1 = (expr_pred_trans_t) p1;
  const expr_pred_trans_t ve1 = (expr_pred_trans_t) p1;
  const expr_pred_trans_t ve2 = (expr_pred_trans_t) p2;
  const expr_pred_trans_t ve2 = (expr_pred_trans_t) p2;
  basic_block b1 = ve1->pred;
  basic_block b1 = ve1->pred;
  basic_block b2 = ve2->pred;
  basic_block b2 = ve2->pred;
  int i;
  int i;
  tree vuse1;
  tree vuse1;
 
 
  /* If they are not translations for the same basic block, they can't
  /* If they are not translations for the same basic block, they can't
     be equal.  */
     be equal.  */
  if (b1 != b2)
  if (b1 != b2)
    return false;
    return false;
 
 
 
 
  /* If they are for the same basic block, determine if the
  /* If they are for the same basic block, determine if the
     expressions are equal.  */
     expressions are equal.  */
  if (!expressions_equal_p (ve1->e, ve2->e))
  if (!expressions_equal_p (ve1->e, ve2->e))
    return false;
    return false;
 
 
  /* Make sure the vuses are equivalent.  */
  /* Make sure the vuses are equivalent.  */
  if (ve1->vuses == ve2->vuses)
  if (ve1->vuses == ve2->vuses)
    return true;
    return true;
 
 
  if (VEC_length (tree, ve1->vuses) != VEC_length (tree, ve2->vuses))
  if (VEC_length (tree, ve1->vuses) != VEC_length (tree, ve2->vuses))
    return false;
    return false;
 
 
  for (i = 0; VEC_iterate (tree, ve1->vuses, i, vuse1); i++)
  for (i = 0; VEC_iterate (tree, ve1->vuses, i, vuse1); i++)
    {
    {
      if (VEC_index (tree, ve2->vuses, i) != vuse1)
      if (VEC_index (tree, ve2->vuses, i) != vuse1)
        return false;
        return false;
    }
    }
 
 
  return true;
  return true;
}
}
 
 
/* Search in the phi translation table for the translation of
/* Search in the phi translation table for the translation of
   expression E in basic block PRED with vuses VUSES.
   expression E in basic block PRED with vuses VUSES.
   Return the translated value, if found, NULL otherwise.  */
   Return the translated value, if found, NULL otherwise.  */
 
 
static inline tree
static inline tree
phi_trans_lookup (tree e, basic_block pred, VEC (tree, gc) *vuses)
phi_trans_lookup (tree e, basic_block pred, VEC (tree, gc) *vuses)
{
{
  void **slot;
  void **slot;
  struct expr_pred_trans_d ept;
  struct expr_pred_trans_d ept;
 
 
  ept.e = e;
  ept.e = e;
  ept.pred = pred;
  ept.pred = pred;
  ept.vuses = vuses;
  ept.vuses = vuses;
  ept.hashcode = vn_compute (e, (unsigned long) pred);
  ept.hashcode = vn_compute (e, (unsigned long) pred);
  slot = htab_find_slot_with_hash (phi_translate_table, &ept, ept.hashcode,
  slot = htab_find_slot_with_hash (phi_translate_table, &ept, ept.hashcode,
                                   NO_INSERT);
                                   NO_INSERT);
  if (!slot)
  if (!slot)
    return NULL;
    return NULL;
  else
  else
    return ((expr_pred_trans_t) *slot)->v;
    return ((expr_pred_trans_t) *slot)->v;
}
}
 
 
 
 
/* Add the tuple mapping from {expression E, basic block PRED, vuses VUSES} to
/* Add the tuple mapping from {expression E, basic block PRED, vuses VUSES} to
   value V, to the phi translation table.  */
   value V, to the phi translation table.  */
 
 
static inline void
static inline void
phi_trans_add (tree e, tree v, basic_block pred, VEC (tree, gc) *vuses)
phi_trans_add (tree e, tree v, basic_block pred, VEC (tree, gc) *vuses)
{
{
  void **slot;
  void **slot;
  expr_pred_trans_t new_pair = XNEW (struct expr_pred_trans_d);
  expr_pred_trans_t new_pair = XNEW (struct expr_pred_trans_d);
  new_pair->e = e;
  new_pair->e = e;
  new_pair->pred = pred;
  new_pair->pred = pred;
  new_pair->vuses = vuses;
  new_pair->vuses = vuses;
  new_pair->v = v;
  new_pair->v = v;
  new_pair->hashcode = vn_compute (e, (unsigned long) pred);
  new_pair->hashcode = vn_compute (e, (unsigned long) pred);
  slot = htab_find_slot_with_hash (phi_translate_table, new_pair,
  slot = htab_find_slot_with_hash (phi_translate_table, new_pair,
                                   new_pair->hashcode, INSERT);
                                   new_pair->hashcode, INSERT);
  if (*slot)
  if (*slot)
    free (*slot);
    free (*slot);
  *slot = (void *) new_pair;
  *slot = (void *) new_pair;
}
}
 
 
 
 
/* Add expression E to the expression set of value V.  */
/* Add expression E to the expression set of value V.  */
 
 
void
void
add_to_value (tree v, tree e)
add_to_value (tree v, tree e)
{
{
  /* Constants have no expression sets.  */
  /* Constants have no expression sets.  */
  if (is_gimple_min_invariant (v))
  if (is_gimple_min_invariant (v))
    return;
    return;
 
 
  if (VALUE_HANDLE_EXPR_SET (v) == NULL)
  if (VALUE_HANDLE_EXPR_SET (v) == NULL)
    VALUE_HANDLE_EXPR_SET (v) = set_new (false);
    VALUE_HANDLE_EXPR_SET (v) = set_new (false);
 
 
  insert_into_set (VALUE_HANDLE_EXPR_SET (v), e);
  insert_into_set (VALUE_HANDLE_EXPR_SET (v), e);
}
}
 
 
 
 
/* Return true if value V exists in the bitmap for SET.  */
/* Return true if value V exists in the bitmap for SET.  */
 
 
static inline bool
static inline bool
value_exists_in_set_bitmap (value_set_t set, tree v)
value_exists_in_set_bitmap (value_set_t set, tree v)
{
{
  if (!set->values)
  if (!set->values)
    return false;
    return false;
 
 
  return bitmap_bit_p (set->values, VALUE_HANDLE_ID (v));
  return bitmap_bit_p (set->values, VALUE_HANDLE_ID (v));
}
}
 
 
 
 
/* Remove value V from the bitmap for SET.  */
/* Remove value V from the bitmap for SET.  */
 
 
static void
static void
value_remove_from_set_bitmap (value_set_t set, tree v)
value_remove_from_set_bitmap (value_set_t set, tree v)
{
{
  gcc_assert (set->indexed);
  gcc_assert (set->indexed);
 
 
  if (!set->values)
  if (!set->values)
    return;
    return;
 
 
  bitmap_clear_bit (set->values, VALUE_HANDLE_ID (v));
  bitmap_clear_bit (set->values, VALUE_HANDLE_ID (v));
}
}
 
 
 
 
/* Insert the value number V into the bitmap of values existing in
/* Insert the value number V into the bitmap of values existing in
   SET.  */
   SET.  */
 
 
static inline void
static inline void
value_insert_into_set_bitmap (value_set_t set, tree v)
value_insert_into_set_bitmap (value_set_t set, tree v)
{
{
  gcc_assert (set->indexed);
  gcc_assert (set->indexed);
 
 
  if (set->values == NULL)
  if (set->values == NULL)
    set->values = BITMAP_ALLOC (&grand_bitmap_obstack);
    set->values = BITMAP_ALLOC (&grand_bitmap_obstack);
 
 
  bitmap_set_bit (set->values, VALUE_HANDLE_ID (v));
  bitmap_set_bit (set->values, VALUE_HANDLE_ID (v));
}
}
 
 
 
 
/* Create a new bitmap set and return it.  */
/* Create a new bitmap set and return it.  */
 
 
static bitmap_set_t
static bitmap_set_t
bitmap_set_new (void)
bitmap_set_new (void)
{
{
  bitmap_set_t ret = (bitmap_set_t) pool_alloc (bitmap_set_pool);
  bitmap_set_t ret = (bitmap_set_t) pool_alloc (bitmap_set_pool);
  ret->expressions = BITMAP_ALLOC (&grand_bitmap_obstack);
  ret->expressions = BITMAP_ALLOC (&grand_bitmap_obstack);
  ret->values = BITMAP_ALLOC (&grand_bitmap_obstack);
  ret->values = BITMAP_ALLOC (&grand_bitmap_obstack);
  return ret;
  return ret;
}
}
 
 
/* Create a new set.  */
/* Create a new set.  */
 
 
static value_set_t
static value_set_t
set_new  (bool indexed)
set_new  (bool indexed)
{
{
  value_set_t ret;
  value_set_t ret;
  ret = (value_set_t) pool_alloc (value_set_pool);
  ret = (value_set_t) pool_alloc (value_set_pool);
  ret->head = ret->tail = NULL;
  ret->head = ret->tail = NULL;
  ret->length = 0;
  ret->length = 0;
  ret->indexed = indexed;
  ret->indexed = indexed;
  ret->values = NULL;
  ret->values = NULL;
  return ret;
  return ret;
}
}
 
 
/* Insert an expression EXPR into a bitmapped set.  */
/* Insert an expression EXPR into a bitmapped set.  */
 
 
static void
static void
bitmap_insert_into_set (bitmap_set_t set, tree expr)
bitmap_insert_into_set (bitmap_set_t set, tree expr)
{
{
  tree val;
  tree val;
  /* XXX: For now, we only let SSA_NAMES into the bitmap sets.  */
  /* XXX: For now, we only let SSA_NAMES into the bitmap sets.  */
  gcc_assert (TREE_CODE (expr) == SSA_NAME);
  gcc_assert (TREE_CODE (expr) == SSA_NAME);
  val = get_value_handle (expr);
  val = get_value_handle (expr);
 
 
  gcc_assert (val);
  gcc_assert (val);
  if (!is_gimple_min_invariant (val))
  if (!is_gimple_min_invariant (val))
  {
  {
    bitmap_set_bit (set->values, VALUE_HANDLE_ID (val));
    bitmap_set_bit (set->values, VALUE_HANDLE_ID (val));
    bitmap_set_bit (set->expressions, SSA_NAME_VERSION (expr));
    bitmap_set_bit (set->expressions, SSA_NAME_VERSION (expr));
  }
  }
}
}
 
 
/* Insert EXPR into SET.  */
/* Insert EXPR into SET.  */
 
 
static void
static void
insert_into_set (value_set_t set, tree expr)
insert_into_set (value_set_t set, tree expr)
{
{
  value_set_node_t newnode = (value_set_node_t) pool_alloc (value_set_node_pool);
  value_set_node_t newnode = (value_set_node_t) pool_alloc (value_set_node_pool);
  tree val = get_value_handle (expr);
  tree val = get_value_handle (expr);
  gcc_assert (val);
  gcc_assert (val);
 
 
  if (is_gimple_min_invariant (val))
  if (is_gimple_min_invariant (val))
    return;
    return;
 
 
  /* For indexed sets, insert the value into the set value bitmap.
  /* For indexed sets, insert the value into the set value bitmap.
     For all sets, add it to the linked list and increment the list
     For all sets, add it to the linked list and increment the list
     length.  */
     length.  */
  if (set->indexed)
  if (set->indexed)
    value_insert_into_set_bitmap (set, val);
    value_insert_into_set_bitmap (set, val);
 
 
  newnode->next = NULL;
  newnode->next = NULL;
  newnode->expr = expr;
  newnode->expr = expr;
  set->length ++;
  set->length ++;
  if (set->head == NULL)
  if (set->head == NULL)
    {
    {
      set->head = set->tail = newnode;
      set->head = set->tail = newnode;
    }
    }
  else
  else
    {
    {
      set->tail->next = newnode;
      set->tail->next = newnode;
      set->tail = newnode;
      set->tail = newnode;
    }
    }
}
}
 
 
/* Copy a bitmapped set ORIG, into bitmapped set DEST.  */
/* Copy a bitmapped set ORIG, into bitmapped set DEST.  */
 
 
static void
static void
bitmap_set_copy (bitmap_set_t dest, bitmap_set_t orig)
bitmap_set_copy (bitmap_set_t dest, bitmap_set_t orig)
{
{
  bitmap_copy (dest->expressions, orig->expressions);
  bitmap_copy (dest->expressions, orig->expressions);
  bitmap_copy (dest->values, orig->values);
  bitmap_copy (dest->values, orig->values);
}
}
 
 
/* Perform bitmapped set operation DEST &= ORIG.  */
/* Perform bitmapped set operation DEST &= ORIG.  */
 
 
static void
static void
bitmap_set_and (bitmap_set_t dest, bitmap_set_t orig)
bitmap_set_and (bitmap_set_t dest, bitmap_set_t orig)
{
{
  bitmap_iterator bi;
  bitmap_iterator bi;
  unsigned int i;
  unsigned int i;
  bitmap temp = BITMAP_ALLOC (&grand_bitmap_obstack);
  bitmap temp = BITMAP_ALLOC (&grand_bitmap_obstack);
 
 
  bitmap_and_into (dest->values, orig->values);
  bitmap_and_into (dest->values, orig->values);
  bitmap_copy (temp, dest->expressions);
  bitmap_copy (temp, dest->expressions);
  EXECUTE_IF_SET_IN_BITMAP (temp, 0, i, bi)
  EXECUTE_IF_SET_IN_BITMAP (temp, 0, i, bi)
    {
    {
      tree name = ssa_name (i);
      tree name = ssa_name (i);
      tree val = get_value_handle (name);
      tree val = get_value_handle (name);
      if (!bitmap_bit_p (dest->values, VALUE_HANDLE_ID (val)))
      if (!bitmap_bit_p (dest->values, VALUE_HANDLE_ID (val)))
        bitmap_clear_bit (dest->expressions, i);
        bitmap_clear_bit (dest->expressions, i);
    }
    }
  BITMAP_FREE (temp);
  BITMAP_FREE (temp);
}
}
 
 
/* Perform bitmapped value set operation DEST = DEST & ~ORIG.  */
/* Perform bitmapped value set operation DEST = DEST & ~ORIG.  */
 
 
static void
static void
bitmap_set_and_compl (bitmap_set_t dest, bitmap_set_t orig)
bitmap_set_and_compl (bitmap_set_t dest, bitmap_set_t orig)
{
{
  bitmap_iterator bi;
  bitmap_iterator bi;
  unsigned int i;
  unsigned int i;
  bitmap temp = BITMAP_ALLOC (&grand_bitmap_obstack);
  bitmap temp = BITMAP_ALLOC (&grand_bitmap_obstack);
 
 
  bitmap_and_compl_into (dest->values, orig->values);
  bitmap_and_compl_into (dest->values, orig->values);
  bitmap_copy (temp, dest->expressions);
  bitmap_copy (temp, dest->expressions);
  EXECUTE_IF_SET_IN_BITMAP (temp, 0, i, bi)
  EXECUTE_IF_SET_IN_BITMAP (temp, 0, i, bi)
    {
    {
      tree name = ssa_name (i);
      tree name = ssa_name (i);
      tree val = get_value_handle (name);
      tree val = get_value_handle (name);
      if (!bitmap_bit_p (dest->values, VALUE_HANDLE_ID (val)))
      if (!bitmap_bit_p (dest->values, VALUE_HANDLE_ID (val)))
        bitmap_clear_bit (dest->expressions, i);
        bitmap_clear_bit (dest->expressions, i);
    }
    }
  BITMAP_FREE (temp);
  BITMAP_FREE (temp);
}
}
 
 
/* Return true if the bitmap set SET is empty.  */
/* Return true if the bitmap set SET is empty.  */
 
 
static bool
static bool
bitmap_set_empty_p (bitmap_set_t set)
bitmap_set_empty_p (bitmap_set_t set)
{
{
  return bitmap_empty_p (set->values);
  return bitmap_empty_p (set->values);
}
}
 
 
/* Copy the set ORIG to the set DEST.  */
/* Copy the set ORIG to the set DEST.  */
 
 
static void
static void
set_copy (value_set_t dest, value_set_t orig)
set_copy (value_set_t dest, value_set_t orig)
{
{
  value_set_node_t node;
  value_set_node_t node;
 
 
  if (!orig || !orig->head)
  if (!orig || !orig->head)
    return;
    return;
 
 
  for (node = orig->head;
  for (node = orig->head;
       node;
       node;
       node = node->next)
       node = node->next)
    {
    {
      insert_into_set (dest, node->expr);
      insert_into_set (dest, node->expr);
    }
    }
}
}
 
 
/* Remove EXPR from SET.  */
/* Remove EXPR from SET.  */
 
 
static void
static void
set_remove (value_set_t set, tree expr)
set_remove (value_set_t set, tree expr)
{
{
  value_set_node_t node, prev;
  value_set_node_t node, prev;
 
 
  /* Remove the value of EXPR from the bitmap, decrement the set
  /* Remove the value of EXPR from the bitmap, decrement the set
     length, and remove it from the actual double linked list.  */
     length, and remove it from the actual double linked list.  */
  value_remove_from_set_bitmap (set, get_value_handle (expr));
  value_remove_from_set_bitmap (set, get_value_handle (expr));
  set->length--;
  set->length--;
  prev = NULL;
  prev = NULL;
  for (node = set->head;
  for (node = set->head;
       node != NULL;
       node != NULL;
       prev = node, node = node->next)
       prev = node, node = node->next)
    {
    {
      if (node->expr == expr)
      if (node->expr == expr)
        {
        {
          if (prev == NULL)
          if (prev == NULL)
            set->head = node->next;
            set->head = node->next;
          else
          else
            prev->next= node->next;
            prev->next= node->next;
 
 
          if (node == set->tail)
          if (node == set->tail)
            set->tail = prev;
            set->tail = prev;
          pool_free (value_set_node_pool, node);
          pool_free (value_set_node_pool, node);
          return;
          return;
        }
        }
    }
    }
}
}
 
 
/* Return true if SET contains the value VAL.  */
/* Return true if SET contains the value VAL.  */
 
 
static bool
static bool
set_contains_value (value_set_t set, tree val)
set_contains_value (value_set_t set, tree val)
{
{
  /* All constants are in every set.  */
  /* All constants are in every set.  */
  if (is_gimple_min_invariant (val))
  if (is_gimple_min_invariant (val))
    return true;
    return true;
 
 
  if (!set || set->length == 0)
  if (!set || set->length == 0)
    return false;
    return false;
 
 
  return value_exists_in_set_bitmap (set, val);
  return value_exists_in_set_bitmap (set, val);
}
}
 
 
/* Return true if bitmapped set SET contains the expression EXPR.  */
/* Return true if bitmapped set SET contains the expression EXPR.  */
static bool
static bool
bitmap_set_contains (bitmap_set_t set, tree expr)
bitmap_set_contains (bitmap_set_t set, tree expr)
{
{
  /* All constants are in every set.  */
  /* All constants are in every set.  */
  if (is_gimple_min_invariant (get_value_handle (expr)))
  if (is_gimple_min_invariant (get_value_handle (expr)))
    return true;
    return true;
 
 
  /* XXX: Bitmapped sets only contain SSA_NAME's for now.  */
  /* XXX: Bitmapped sets only contain SSA_NAME's for now.  */
  if (TREE_CODE (expr) != SSA_NAME)
  if (TREE_CODE (expr) != SSA_NAME)
    return false;
    return false;
  return bitmap_bit_p (set->expressions, SSA_NAME_VERSION (expr));
  return bitmap_bit_p (set->expressions, SSA_NAME_VERSION (expr));
}
}
 
 
 
 
/* Return true if bitmapped set SET contains the value VAL.  */
/* Return true if bitmapped set SET contains the value VAL.  */
 
 
static bool
static bool
bitmap_set_contains_value (bitmap_set_t set, tree val)
bitmap_set_contains_value (bitmap_set_t set, tree val)
{
{
  if (is_gimple_min_invariant (val))
  if (is_gimple_min_invariant (val))
    return true;
    return true;
  return bitmap_bit_p (set->values, VALUE_HANDLE_ID (val));
  return bitmap_bit_p (set->values, VALUE_HANDLE_ID (val));
}
}
 
 
/* Replace an instance of value LOOKFOR with expression EXPR in SET.  */
/* Replace an instance of value LOOKFOR with expression EXPR in SET.  */
 
 
static void
static void
bitmap_set_replace_value (bitmap_set_t set, tree lookfor, tree expr)
bitmap_set_replace_value (bitmap_set_t set, tree lookfor, tree expr)
{
{
  value_set_t exprset;
  value_set_t exprset;
  value_set_node_t node;
  value_set_node_t node;
  if (is_gimple_min_invariant (lookfor))
  if (is_gimple_min_invariant (lookfor))
    return;
    return;
  if (!bitmap_set_contains_value (set, lookfor))
  if (!bitmap_set_contains_value (set, lookfor))
    return;
    return;
 
 
  /* The number of expressions having a given value is usually
  /* The number of expressions having a given value is usually
     significantly less than the total number of expressions in SET.
     significantly less than the total number of expressions in SET.
     Thus, rather than check, for each expression in SET, whether it
     Thus, rather than check, for each expression in SET, whether it
     has the value LOOKFOR, we walk the reverse mapping that tells us
     has the value LOOKFOR, we walk the reverse mapping that tells us
     what expressions have a given value, and see if any of those
     what expressions have a given value, and see if any of those
     expressions are in our set.  For large testcases, this is about
     expressions are in our set.  For large testcases, this is about
     5-10x faster than walking the bitmap.  If this is somehow a
     5-10x faster than walking the bitmap.  If this is somehow a
     significant lose for some cases, we can choose which set to walk
     significant lose for some cases, we can choose which set to walk
     based on the set size.  */
     based on the set size.  */
  exprset = VALUE_HANDLE_EXPR_SET (lookfor);
  exprset = VALUE_HANDLE_EXPR_SET (lookfor);
  for (node = exprset->head; node; node = node->next)
  for (node = exprset->head; node; node = node->next)
    {
    {
      if (TREE_CODE (node->expr) == SSA_NAME)
      if (TREE_CODE (node->expr) == SSA_NAME)
        {
        {
          if (bitmap_bit_p (set->expressions, SSA_NAME_VERSION (node->expr)))
          if (bitmap_bit_p (set->expressions, SSA_NAME_VERSION (node->expr)))
            {
            {
              bitmap_clear_bit (set->expressions, SSA_NAME_VERSION (node->expr));
              bitmap_clear_bit (set->expressions, SSA_NAME_VERSION (node->expr));
              bitmap_set_bit (set->expressions, SSA_NAME_VERSION (expr));
              bitmap_set_bit (set->expressions, SSA_NAME_VERSION (expr));
              return;
              return;
            }
            }
        }
        }
    }
    }
}
}
 
 
/* Subtract bitmapped set B from value set A, and return the new set.  */
/* Subtract bitmapped set B from value set A, and return the new set.  */
 
 
static value_set_t
static value_set_t
bitmap_set_subtract_from_value_set (value_set_t a, bitmap_set_t b,
bitmap_set_subtract_from_value_set (value_set_t a, bitmap_set_t b,
                                    bool indexed)
                                    bool indexed)
{
{
  value_set_t ret = set_new (indexed);
  value_set_t ret = set_new (indexed);
  value_set_node_t node;
  value_set_node_t node;
  for (node = a->head;
  for (node = a->head;
       node;
       node;
       node = node->next)
       node = node->next)
    {
    {
      if (!bitmap_set_contains (b, node->expr))
      if (!bitmap_set_contains (b, node->expr))
        insert_into_set (ret, node->expr);
        insert_into_set (ret, node->expr);
    }
    }
  return ret;
  return ret;
}
}
 
 
/* Return true if two sets are equal.  */
/* Return true if two sets are equal.  */
 
 
static bool
static bool
set_equal (value_set_t a, value_set_t b)
set_equal (value_set_t a, value_set_t b)
{
{
  value_set_node_t node;
  value_set_node_t node;
 
 
  if (a->length != b->length)
  if (a->length != b->length)
    return false;
    return false;
  for (node = a->head;
  for (node = a->head;
       node;
       node;
       node = node->next)
       node = node->next)
    {
    {
      if (!set_contains_value (b, get_value_handle (node->expr)))
      if (!set_contains_value (b, get_value_handle (node->expr)))
        return false;
        return false;
    }
    }
  return true;
  return true;
}
}
 
 
/* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
/* Replace an instance of EXPR's VALUE with EXPR in SET if it exists,
   and add it otherwise.  */
   and add it otherwise.  */
 
 
static void
static void
bitmap_value_replace_in_set (bitmap_set_t set, tree expr)
bitmap_value_replace_in_set (bitmap_set_t set, tree expr)
{
{
  tree val = get_value_handle (expr);
  tree val = get_value_handle (expr);
  if (bitmap_set_contains_value (set, val))
  if (bitmap_set_contains_value (set, val))
    bitmap_set_replace_value (set, val, expr);
    bitmap_set_replace_value (set, val, expr);
  else
  else
    bitmap_insert_into_set (set, expr);
    bitmap_insert_into_set (set, expr);
}
}
 
 
/* Insert EXPR into SET if EXPR's value is not already present in
/* Insert EXPR into SET if EXPR's value is not already present in
   SET.  */
   SET.  */
 
 
static void
static void
bitmap_value_insert_into_set (bitmap_set_t set, tree expr)
bitmap_value_insert_into_set (bitmap_set_t set, tree expr)
{
{
  tree val = get_value_handle (expr);
  tree val = get_value_handle (expr);
 
 
  if (is_gimple_min_invariant (val))
  if (is_gimple_min_invariant (val))
    return;
    return;
 
 
  if (!bitmap_set_contains_value (set, val))
  if (!bitmap_set_contains_value (set, val))
    bitmap_insert_into_set (set, expr);
    bitmap_insert_into_set (set, expr);
}
}
 
 
/* Insert the value for EXPR into SET, if it doesn't exist already.  */
/* Insert the value for EXPR into SET, if it doesn't exist already.  */
 
 
static void
static void
value_insert_into_set (value_set_t set, tree expr)
value_insert_into_set (value_set_t set, tree expr)
{
{
  tree val = get_value_handle (expr);
  tree val = get_value_handle (expr);
 
 
  /* Constant and invariant values exist everywhere, and thus,
  /* Constant and invariant values exist everywhere, and thus,
     actually keeping them in the sets is pointless.  */
     actually keeping them in the sets is pointless.  */
  if (is_gimple_min_invariant (val))
  if (is_gimple_min_invariant (val))
    return;
    return;
 
 
  if (!set_contains_value (set, val))
  if (!set_contains_value (set, val))
    insert_into_set (set, expr);
    insert_into_set (set, expr);
}
}
 
 
 
 
/* Print out SET to OUTFILE.  */
/* Print out SET to OUTFILE.  */
 
 
static void
static void
bitmap_print_value_set (FILE *outfile, bitmap_set_t set,
bitmap_print_value_set (FILE *outfile, bitmap_set_t set,
                        const char *setname, int blockindex)
                        const char *setname, int blockindex)
{
{
  fprintf (outfile, "%s[%d] := { ", setname, blockindex);
  fprintf (outfile, "%s[%d] := { ", setname, blockindex);
  if (set)
  if (set)
    {
    {
      bool first = true;
      bool first = true;
      unsigned i;
      unsigned i;
      bitmap_iterator bi;
      bitmap_iterator bi;
 
 
      EXECUTE_IF_SET_IN_BITMAP (set->expressions, 0, i, bi)
      EXECUTE_IF_SET_IN_BITMAP (set->expressions, 0, i, bi)
        {
        {
          if (!first)
          if (!first)
            fprintf (outfile, ", ");
            fprintf (outfile, ", ");
          first = false;
          first = false;
          print_generic_expr (outfile, ssa_name (i), 0);
          print_generic_expr (outfile, ssa_name (i), 0);
 
 
          fprintf (outfile, " (");
          fprintf (outfile, " (");
          print_generic_expr (outfile, get_value_handle (ssa_name (i)), 0);
          print_generic_expr (outfile, get_value_handle (ssa_name (i)), 0);
          fprintf (outfile, ") ");
          fprintf (outfile, ") ");
        }
        }
    }
    }
  fprintf (outfile, " }\n");
  fprintf (outfile, " }\n");
}
}
/* Print out the value_set SET to OUTFILE.  */
/* Print out the value_set SET to OUTFILE.  */
 
 
static void
static void
print_value_set (FILE *outfile, value_set_t set,
print_value_set (FILE *outfile, value_set_t set,
                 const char *setname, int blockindex)
                 const char *setname, int blockindex)
{
{
  value_set_node_t node;
  value_set_node_t node;
  fprintf (outfile, "%s[%d] := { ", setname, blockindex);
  fprintf (outfile, "%s[%d] := { ", setname, blockindex);
  if (set)
  if (set)
    {
    {
      for (node = set->head;
      for (node = set->head;
           node;
           node;
           node = node->next)
           node = node->next)
        {
        {
          print_generic_expr (outfile, node->expr, 0);
          print_generic_expr (outfile, node->expr, 0);
 
 
          fprintf (outfile, " (");
          fprintf (outfile, " (");
          print_generic_expr (outfile, get_value_handle (node->expr), 0);
          print_generic_expr (outfile, get_value_handle (node->expr), 0);
          fprintf (outfile, ") ");
          fprintf (outfile, ") ");
 
 
          if (node->next)
          if (node->next)
            fprintf (outfile, ", ");
            fprintf (outfile, ", ");
        }
        }
    }
    }
 
 
  fprintf (outfile, " }\n");
  fprintf (outfile, " }\n");
}
}
 
 
/* Print out the expressions that have VAL to OUTFILE.  */
/* Print out the expressions that have VAL to OUTFILE.  */
 
 
void
void
print_value_expressions (FILE *outfile, tree val)
print_value_expressions (FILE *outfile, tree val)
{
{
  if (VALUE_HANDLE_EXPR_SET (val))
  if (VALUE_HANDLE_EXPR_SET (val))
    {
    {
      char s[10];
      char s[10];
      sprintf (s, "VH.%04d", VALUE_HANDLE_ID (val));
      sprintf (s, "VH.%04d", VALUE_HANDLE_ID (val));
      print_value_set (outfile, VALUE_HANDLE_EXPR_SET (val), s, 0);
      print_value_set (outfile, VALUE_HANDLE_EXPR_SET (val), s, 0);
    }
    }
}
}
 
 
 
 
void
void
debug_value_expressions (tree val)
debug_value_expressions (tree val)
{
{
  print_value_expressions (stderr, val);
  print_value_expressions (stderr, val);
}
}
 
 
 
 
void debug_value_set (value_set_t, const char *, int);
void debug_value_set (value_set_t, const char *, int);
 
 
void
void
debug_value_set (value_set_t set, const char *setname, int blockindex)
debug_value_set (value_set_t set, const char *setname, int blockindex)
{
{
  print_value_set (stderr, set, setname, blockindex);
  print_value_set (stderr, set, setname, blockindex);
}
}
 
 
/* Return the folded version of T if T, when folded, is a gimple
/* Return the folded version of T if T, when folded, is a gimple
   min_invariant.  Otherwise, return T.  */
   min_invariant.  Otherwise, return T.  */
 
 
static tree
static tree
fully_constant_expression (tree t)
fully_constant_expression (tree t)
{
{
  tree folded;
  tree folded;
  folded = fold (t);
  folded = fold (t);
  if (folded && is_gimple_min_invariant (folded))
  if (folded && is_gimple_min_invariant (folded))
    return folded;
    return folded;
  return t;
  return t;
}
}
 
 
/* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
/* Return a copy of a chain of nodes, chained through the TREE_CHAIN field.
   For example, this can copy a list made of TREE_LIST nodes.
   For example, this can copy a list made of TREE_LIST nodes.
   Allocates the nodes in list_node_pool*/
   Allocates the nodes in list_node_pool*/
 
 
static tree
static tree
pool_copy_list (tree list)
pool_copy_list (tree list)
{
{
  tree head;
  tree head;
  tree prev, next;
  tree prev, next;
 
 
  if (list == 0)
  if (list == 0)
    return 0;
    return 0;
  head = (tree) pool_alloc (list_node_pool);
  head = (tree) pool_alloc (list_node_pool);
 
 
  memcpy (head, list, tree_size (list));
  memcpy (head, list, tree_size (list));
  prev = head;
  prev = head;
 
 
  next = TREE_CHAIN (list);
  next = TREE_CHAIN (list);
  while (next)
  while (next)
    {
    {
      TREE_CHAIN (prev) = (tree) pool_alloc (list_node_pool);
      TREE_CHAIN (prev) = (tree) pool_alloc (list_node_pool);
      memcpy (TREE_CHAIN (prev), next, tree_size (next));
      memcpy (TREE_CHAIN (prev), next, tree_size (next));
      prev = TREE_CHAIN (prev);
      prev = TREE_CHAIN (prev);
      next = TREE_CHAIN (next);
      next = TREE_CHAIN (next);
    }
    }
  return head;
  return head;
}
}
 
 
/* Translate the vuses in the VUSES vector backwards through phi
/* Translate the vuses in the VUSES vector backwards through phi
   nodes, so that they have the value they would have in BLOCK. */
   nodes, so that they have the value they would have in BLOCK. */
 
 
static VEC(tree, gc) *
static VEC(tree, gc) *
translate_vuses_through_block (VEC (tree, gc) *vuses, basic_block block)
translate_vuses_through_block (VEC (tree, gc) *vuses, basic_block block)
{
{
  tree oldvuse;
  tree oldvuse;
  VEC(tree, gc) *result = NULL;
  VEC(tree, gc) *result = NULL;
  int i;
  int i;
 
 
  for (i = 0; VEC_iterate (tree, vuses, i, oldvuse); i++)
  for (i = 0; VEC_iterate (tree, vuses, i, oldvuse); i++)
    {
    {
      tree phi = SSA_NAME_DEF_STMT (oldvuse);
      tree phi = SSA_NAME_DEF_STMT (oldvuse);
      if (TREE_CODE (phi) == PHI_NODE)
      if (TREE_CODE (phi) == PHI_NODE)
        {
        {
          edge e = find_edge (block, bb_for_stmt (phi));
          edge e = find_edge (block, bb_for_stmt (phi));
          if (e)
          if (e)
            {
            {
              tree def = PHI_ARG_DEF (phi, e->dest_idx);
              tree def = PHI_ARG_DEF (phi, e->dest_idx);
              if (def != oldvuse)
              if (def != oldvuse)
                {
                {
                  if (!result)
                  if (!result)
                    result = VEC_copy (tree, gc, vuses);
                    result = VEC_copy (tree, gc, vuses);
                  VEC_replace (tree, result, i, def);
                  VEC_replace (tree, result, i, def);
                }
                }
            }
            }
        }
        }
    }
    }
  if (result)
  if (result)
    {
    {
      sort_vuses (result);
      sort_vuses (result);
      return result;
      return result;
    }
    }
  return vuses;
  return vuses;
 
 
}
}
/* Translate EXPR using phis in PHIBLOCK, so that it has the values of
/* Translate EXPR using phis in PHIBLOCK, so that it has the values of
   the phis in PRED.  Return NULL if we can't find a leader for each
   the phis in PRED.  Return NULL if we can't find a leader for each
   part of the translated expression.  */
   part of the translated expression.  */
 
 
static tree
static tree
phi_translate (tree expr, value_set_t set, basic_block pred,
phi_translate (tree expr, value_set_t set, basic_block pred,
               basic_block phiblock)
               basic_block phiblock)
{
{
  tree phitrans = NULL;
  tree phitrans = NULL;
  tree oldexpr = expr;
  tree oldexpr = expr;
  if (expr == NULL)
  if (expr == NULL)
    return NULL;
    return NULL;
 
 
  if (is_gimple_min_invariant (expr))
  if (is_gimple_min_invariant (expr))
    return expr;
    return expr;
 
 
  /* Phi translations of a given expression don't change.  */
  /* Phi translations of a given expression don't change.  */
  if (EXPR_P (expr))
  if (EXPR_P (expr))
    {
    {
      tree vh;
      tree vh;
 
 
      vh = get_value_handle (expr);
      vh = get_value_handle (expr);
      if (vh && TREE_CODE (vh) == VALUE_HANDLE)
      if (vh && TREE_CODE (vh) == VALUE_HANDLE)
        phitrans = phi_trans_lookup (expr, pred, VALUE_HANDLE_VUSES (vh));
        phitrans = phi_trans_lookup (expr, pred, VALUE_HANDLE_VUSES (vh));
      else
      else
        phitrans = phi_trans_lookup (expr, pred, NULL);
        phitrans = phi_trans_lookup (expr, pred, NULL);
    }
    }
  else
  else
    phitrans = phi_trans_lookup (expr, pred, NULL);
    phitrans = phi_trans_lookup (expr, pred, NULL);
 
 
  if (phitrans)
  if (phitrans)
    return phitrans;
    return phitrans;
 
 
  switch (TREE_CODE_CLASS (TREE_CODE (expr)))
  switch (TREE_CODE_CLASS (TREE_CODE (expr)))
    {
    {
    case tcc_expression:
    case tcc_expression:
      {
      {
        if (TREE_CODE (expr) != CALL_EXPR)
        if (TREE_CODE (expr) != CALL_EXPR)
          return NULL;
          return NULL;
        else
        else
          {
          {
            tree oldop0 = TREE_OPERAND (expr, 0);
            tree oldop0 = TREE_OPERAND (expr, 0);
            tree oldarglist = TREE_OPERAND (expr, 1);
            tree oldarglist = TREE_OPERAND (expr, 1);
            tree oldop2 = TREE_OPERAND (expr, 2);
            tree oldop2 = TREE_OPERAND (expr, 2);
            tree newop0;
            tree newop0;
            tree newarglist;
            tree newarglist;
            tree newop2 = NULL;
            tree newop2 = NULL;
            tree oldwalker;
            tree oldwalker;
            tree newwalker;
            tree newwalker;
            tree newexpr;
            tree newexpr;
            tree vh = get_value_handle (expr);
            tree vh = get_value_handle (expr);
            bool listchanged = false;
            bool listchanged = false;
            VEC (tree, gc) *vuses = VALUE_HANDLE_VUSES (vh);
            VEC (tree, gc) *vuses = VALUE_HANDLE_VUSES (vh);
            VEC (tree, gc) *tvuses;
            VEC (tree, gc) *tvuses;
 
 
            /* Call expressions are kind of weird because they have an
            /* Call expressions are kind of weird because they have an
               argument list.  We don't want to value number the list
               argument list.  We don't want to value number the list
               as one value number, because that doesn't make much
               as one value number, because that doesn't make much
               sense, and just breaks the support functions we call,
               sense, and just breaks the support functions we call,
               which expect TREE_OPERAND (call_expr, 2) to be a
               which expect TREE_OPERAND (call_expr, 2) to be a
               TREE_LIST. */
               TREE_LIST. */
 
 
            newop0 = phi_translate (find_leader (set, oldop0),
            newop0 = phi_translate (find_leader (set, oldop0),
                                    set, pred, phiblock);
                                    set, pred, phiblock);
            if (newop0 == NULL)
            if (newop0 == NULL)
              return NULL;
              return NULL;
            if (oldop2)
            if (oldop2)
              {
              {
                newop2 = phi_translate (find_leader (set, oldop2),
                newop2 = phi_translate (find_leader (set, oldop2),
                                        set, pred, phiblock);
                                        set, pred, phiblock);
                if (newop2 == NULL)
                if (newop2 == NULL)
                  return NULL;
                  return NULL;
              }
              }
 
 
            /* phi translate the argument list piece by piece.
            /* phi translate the argument list piece by piece.
 
 
              We could actually build the list piece by piece here,
              We could actually build the list piece by piece here,
              but it's likely to not be worth the memory we will save,
              but it's likely to not be worth the memory we will save,
              unless you have millions of call arguments.  */
              unless you have millions of call arguments.  */
 
 
            newarglist = pool_copy_list (oldarglist);
            newarglist = pool_copy_list (oldarglist);
            for (oldwalker = oldarglist, newwalker = newarglist;
            for (oldwalker = oldarglist, newwalker = newarglist;
                 oldwalker && newwalker;
                 oldwalker && newwalker;
                 oldwalker = TREE_CHAIN (oldwalker),
                 oldwalker = TREE_CHAIN (oldwalker),
                   newwalker = TREE_CHAIN (newwalker))
                   newwalker = TREE_CHAIN (newwalker))
              {
              {
 
 
                tree oldval = TREE_VALUE (oldwalker);
                tree oldval = TREE_VALUE (oldwalker);
                tree newval;
                tree newval;
                if (oldval)
                if (oldval)
                  {
                  {
                    /* This may seem like a weird place for this
                    /* This may seem like a weird place for this
                       check, but it's actually the easiest place to
                       check, but it's actually the easiest place to
                       do it.  We can't do it lower on in the
                       do it.  We can't do it lower on in the
                       recursion because it's valid for pieces of a
                       recursion because it's valid for pieces of a
                       component ref to be of AGGREGATE_TYPE, as long
                       component ref to be of AGGREGATE_TYPE, as long
                       as the outermost one is not.
                       as the outermost one is not.
                       To avoid *that* case, we have a check for
                       To avoid *that* case, we have a check for
                       AGGREGATE_TYPE_P in insert_aux.  However, that
                       AGGREGATE_TYPE_P in insert_aux.  However, that
                       check will *not* catch this case because here
                       check will *not* catch this case because here
                       it occurs in the argument list.  */
                       it occurs in the argument list.  */
                    if (AGGREGATE_TYPE_P (TREE_TYPE (oldval)))
                    if (AGGREGATE_TYPE_P (TREE_TYPE (oldval)))
                      return NULL;
                      return NULL;
                    newval = phi_translate (find_leader (set, oldval),
                    newval = phi_translate (find_leader (set, oldval),
                                            set, pred, phiblock);
                                            set, pred, phiblock);
                    if (newval == NULL)
                    if (newval == NULL)
                      return NULL;
                      return NULL;
                    if (newval != oldval)
                    if (newval != oldval)
                      {
                      {
                        listchanged = true;
                        listchanged = true;
                        TREE_VALUE (newwalker) = get_value_handle (newval);
                        TREE_VALUE (newwalker) = get_value_handle (newval);
                      }
                      }
                  }
                  }
              }
              }
            if (listchanged)
            if (listchanged)
              vn_lookup_or_add (newarglist, NULL);
              vn_lookup_or_add (newarglist, NULL);
 
 
            tvuses = translate_vuses_through_block (vuses, pred);
            tvuses = translate_vuses_through_block (vuses, pred);
 
 
            if (listchanged || (newop0 != oldop0) || (oldop2 != newop2)
            if (listchanged || (newop0 != oldop0) || (oldop2 != newop2)
                || vuses != tvuses)
                || vuses != tvuses)
              {
              {
                newexpr = (tree) pool_alloc (expression_node_pool);
                newexpr = (tree) pool_alloc (expression_node_pool);
                memcpy (newexpr, expr, tree_size (expr));
                memcpy (newexpr, expr, tree_size (expr));
                TREE_OPERAND (newexpr, 0) = newop0 == oldop0 ? oldop0 : get_value_handle (newop0);
                TREE_OPERAND (newexpr, 0) = newop0 == oldop0 ? oldop0 : get_value_handle (newop0);
                TREE_OPERAND (newexpr, 1) = listchanged ? newarglist : oldarglist;
                TREE_OPERAND (newexpr, 1) = listchanged ? newarglist : oldarglist;
                TREE_OPERAND (newexpr, 2) = newop2 == oldop2 ? oldop2 : get_value_handle (newop2);
                TREE_OPERAND (newexpr, 2) = newop2 == oldop2 ? oldop2 : get_value_handle (newop2);
                newexpr->common.ann = NULL;
                newexpr->common.ann = NULL;
                vn_lookup_or_add_with_vuses (newexpr, tvuses);
                vn_lookup_or_add_with_vuses (newexpr, tvuses);
                expr = newexpr;
                expr = newexpr;
                phi_trans_add (oldexpr, newexpr, pred, tvuses);
                phi_trans_add (oldexpr, newexpr, pred, tvuses);
              }
              }
          }
          }
      }
      }
      return expr;
      return expr;
 
 
    case tcc_declaration:
    case tcc_declaration:
      {
      {
        VEC (tree, gc) * oldvuses = NULL;
        VEC (tree, gc) * oldvuses = NULL;
        VEC (tree, gc) * newvuses = NULL;
        VEC (tree, gc) * newvuses = NULL;
 
 
        oldvuses = VALUE_HANDLE_VUSES (get_value_handle (expr));
        oldvuses = VALUE_HANDLE_VUSES (get_value_handle (expr));
        if (oldvuses)
        if (oldvuses)
          newvuses = translate_vuses_through_block (oldvuses, pred);
          newvuses = translate_vuses_through_block (oldvuses, pred);
 
 
        if (oldvuses != newvuses)
        if (oldvuses != newvuses)
          vn_lookup_or_add_with_vuses (expr, newvuses);
          vn_lookup_or_add_with_vuses (expr, newvuses);
 
 
        phi_trans_add (oldexpr, expr, pred, newvuses);
        phi_trans_add (oldexpr, expr, pred, newvuses);
      }
      }
      return expr;
      return expr;
 
 
    case tcc_reference:
    case tcc_reference:
      {
      {
        tree oldop0 = TREE_OPERAND (expr, 0);
        tree oldop0 = TREE_OPERAND (expr, 0);
        tree oldop1 = NULL;
        tree oldop1 = NULL;
        tree newop0;
        tree newop0;
        tree newop1 = NULL;
        tree newop1 = NULL;
        tree oldop2 = NULL;
        tree oldop2 = NULL;
        tree newop2 = NULL;
        tree newop2 = NULL;
        tree oldop3 = NULL;
        tree oldop3 = NULL;
        tree newop3 = NULL;
        tree newop3 = NULL;
        tree newexpr;
        tree newexpr;
        VEC (tree, gc) * oldvuses = NULL;
        VEC (tree, gc) * oldvuses = NULL;
        VEC (tree, gc) * newvuses = NULL;
        VEC (tree, gc) * newvuses = NULL;
 
 
        if (TREE_CODE (expr) != INDIRECT_REF
        if (TREE_CODE (expr) != INDIRECT_REF
            && TREE_CODE (expr) != COMPONENT_REF
            && TREE_CODE (expr) != COMPONENT_REF
            && TREE_CODE (expr) != ARRAY_REF)
            && TREE_CODE (expr) != ARRAY_REF)
          return NULL;
          return NULL;
 
 
        newop0 = phi_translate (find_leader (set, oldop0),
        newop0 = phi_translate (find_leader (set, oldop0),
                                set, pred, phiblock);
                                set, pred, phiblock);
        if (newop0 == NULL)
        if (newop0 == NULL)
          return NULL;
          return NULL;
 
 
        if (TREE_CODE (expr) == ARRAY_REF)
        if (TREE_CODE (expr) == ARRAY_REF)
          {
          {
            oldop1 = TREE_OPERAND (expr, 1);
            oldop1 = TREE_OPERAND (expr, 1);
            newop1 = phi_translate (find_leader (set, oldop1),
            newop1 = phi_translate (find_leader (set, oldop1),
                                    set, pred, phiblock);
                                    set, pred, phiblock);
 
 
            if (newop1 == NULL)
            if (newop1 == NULL)
              return NULL;
              return NULL;
            oldop2 = TREE_OPERAND (expr, 2);
            oldop2 = TREE_OPERAND (expr, 2);
            if (oldop2)
            if (oldop2)
              {
              {
                newop2 = phi_translate (find_leader (set, oldop2),
                newop2 = phi_translate (find_leader (set, oldop2),
                                        set, pred, phiblock);
                                        set, pred, phiblock);
 
 
                if (newop2 == NULL)
                if (newop2 == NULL)
                  return NULL;
                  return NULL;
              }
              }
            oldop3 = TREE_OPERAND (expr, 3);
            oldop3 = TREE_OPERAND (expr, 3);
            if (oldop3)
            if (oldop3)
              {
              {
                newop3 = phi_translate (find_leader (set, oldop3),
                newop3 = phi_translate (find_leader (set, oldop3),
                                        set, pred, phiblock);
                                        set, pred, phiblock);
 
 
                if (newop3 == NULL)
                if (newop3 == NULL)
                  return NULL;
                  return NULL;
              }
              }
          }
          }
 
 
        oldvuses = VALUE_HANDLE_VUSES (get_value_handle (expr));
        oldvuses = VALUE_HANDLE_VUSES (get_value_handle (expr));
        if (oldvuses)
        if (oldvuses)
          newvuses = translate_vuses_through_block (oldvuses, pred);
          newvuses = translate_vuses_through_block (oldvuses, pred);
 
 
        if (newop0 != oldop0 || newvuses != oldvuses
        if (newop0 != oldop0 || newvuses != oldvuses
            || newop1 != oldop1
            || newop1 != oldop1
            || newop2 != oldop2
            || newop2 != oldop2
            || newop3 != oldop3)
            || newop3 != oldop3)
          {
          {
            tree t;
            tree t;
 
 
            newexpr = pool_alloc (reference_node_pool);
            newexpr = pool_alloc (reference_node_pool);
            memcpy (newexpr, expr, tree_size (expr));
            memcpy (newexpr, expr, tree_size (expr));
            TREE_OPERAND (newexpr, 0) = get_value_handle (newop0);
            TREE_OPERAND (newexpr, 0) = get_value_handle (newop0);
            if (TREE_CODE (expr) == ARRAY_REF)
            if (TREE_CODE (expr) == ARRAY_REF)
              {
              {
                TREE_OPERAND (newexpr, 1) = get_value_handle (newop1);
                TREE_OPERAND (newexpr, 1) = get_value_handle (newop1);
                if (newop2)
                if (newop2)
                  TREE_OPERAND (newexpr, 2) = get_value_handle (newop2);
                  TREE_OPERAND (newexpr, 2) = get_value_handle (newop2);
                if (newop3)
                if (newop3)
                  TREE_OPERAND (newexpr, 3) = get_value_handle (newop3);
                  TREE_OPERAND (newexpr, 3) = get_value_handle (newop3);
              }
              }
 
 
            t = fully_constant_expression (newexpr);
            t = fully_constant_expression (newexpr);
 
 
            if (t != newexpr)
            if (t != newexpr)
              {
              {
                pool_free (reference_node_pool, newexpr);
                pool_free (reference_node_pool, newexpr);
                newexpr = t;
                newexpr = t;
              }
              }
            else
            else
              {
              {
                newexpr->common.ann = NULL;
                newexpr->common.ann = NULL;
                vn_lookup_or_add_with_vuses (newexpr, newvuses);
                vn_lookup_or_add_with_vuses (newexpr, newvuses);
              }
              }
            expr = newexpr;
            expr = newexpr;
            phi_trans_add (oldexpr, newexpr, pred, newvuses);
            phi_trans_add (oldexpr, newexpr, pred, newvuses);
          }
          }
      }
      }
      return expr;
      return expr;
      break;
      break;
 
 
    case tcc_binary:
    case tcc_binary:
    case tcc_comparison:
    case tcc_comparison:
      {
      {
        tree oldop1 = TREE_OPERAND (expr, 0);
        tree oldop1 = TREE_OPERAND (expr, 0);
        tree oldop2 = TREE_OPERAND (expr, 1);
        tree oldop2 = TREE_OPERAND (expr, 1);
        tree newop1;
        tree newop1;
        tree newop2;
        tree newop2;
        tree newexpr;
        tree newexpr;
 
 
        newop1 = phi_translate (find_leader (set, oldop1),
        newop1 = phi_translate (find_leader (set, oldop1),
                                set, pred, phiblock);
                                set, pred, phiblock);
        if (newop1 == NULL)
        if (newop1 == NULL)
          return NULL;
          return NULL;
        newop2 = phi_translate (find_leader (set, oldop2),
        newop2 = phi_translate (find_leader (set, oldop2),
                                set, pred, phiblock);
                                set, pred, phiblock);
        if (newop2 == NULL)
        if (newop2 == NULL)
          return NULL;
          return NULL;
        if (newop1 != oldop1 || newop2 != oldop2)
        if (newop1 != oldop1 || newop2 != oldop2)
          {
          {
            tree t;
            tree t;
            newexpr = (tree) pool_alloc (binary_node_pool);
            newexpr = (tree) pool_alloc (binary_node_pool);
            memcpy (newexpr, expr, tree_size (expr));
            memcpy (newexpr, expr, tree_size (expr));
            TREE_OPERAND (newexpr, 0) = newop1 == oldop1 ? oldop1 : get_value_handle (newop1);
            TREE_OPERAND (newexpr, 0) = newop1 == oldop1 ? oldop1 : get_value_handle (newop1);
            TREE_OPERAND (newexpr, 1) = newop2 == oldop2 ? oldop2 : get_value_handle (newop2);
            TREE_OPERAND (newexpr, 1) = newop2 == oldop2 ? oldop2 : get_value_handle (newop2);
            t = fully_constant_expression (newexpr);
            t = fully_constant_expression (newexpr);
            if (t != newexpr)
            if (t != newexpr)
              {
              {
                pool_free (binary_node_pool, newexpr);
                pool_free (binary_node_pool, newexpr);
                newexpr = t;
                newexpr = t;
              }
              }
            else
            else
              {
              {
                newexpr->common.ann = NULL;
                newexpr->common.ann = NULL;
                vn_lookup_or_add (newexpr, NULL);
                vn_lookup_or_add (newexpr, NULL);
              }
              }
            expr = newexpr;
            expr = newexpr;
            phi_trans_add (oldexpr, newexpr, pred, NULL);
            phi_trans_add (oldexpr, newexpr, pred, NULL);
          }
          }
      }
      }
      return expr;
      return expr;
 
 
    case tcc_unary:
    case tcc_unary:
      {
      {
        tree oldop1 = TREE_OPERAND (expr, 0);
        tree oldop1 = TREE_OPERAND (expr, 0);
        tree newop1;
        tree newop1;
        tree newexpr;
        tree newexpr;
 
 
        newop1 = phi_translate (find_leader (set, oldop1),
        newop1 = phi_translate (find_leader (set, oldop1),
                                set, pred, phiblock);
                                set, pred, phiblock);
        if (newop1 == NULL)
        if (newop1 == NULL)
          return NULL;
          return NULL;
        if (newop1 != oldop1)
        if (newop1 != oldop1)
          {
          {
            tree t;
            tree t;
            newexpr = (tree) pool_alloc (unary_node_pool);
            newexpr = (tree) pool_alloc (unary_node_pool);
            memcpy (newexpr, expr, tree_size (expr));
            memcpy (newexpr, expr, tree_size (expr));
            TREE_OPERAND (newexpr, 0) = get_value_handle (newop1);
            TREE_OPERAND (newexpr, 0) = get_value_handle (newop1);
            t = fully_constant_expression (newexpr);
            t = fully_constant_expression (newexpr);
            if (t != newexpr)
            if (t != newexpr)
              {
              {
                pool_free (unary_node_pool, newexpr);
                pool_free (unary_node_pool, newexpr);
                newexpr = t;
                newexpr = t;
              }
              }
            else
            else
              {
              {
                newexpr->common.ann = NULL;
                newexpr->common.ann = NULL;
                vn_lookup_or_add (newexpr, NULL);
                vn_lookup_or_add (newexpr, NULL);
              }
              }
            expr = newexpr;
            expr = newexpr;
            phi_trans_add (oldexpr, newexpr, pred, NULL);
            phi_trans_add (oldexpr, newexpr, pred, NULL);
          }
          }
      }
      }
      return expr;
      return expr;
 
 
    case tcc_exceptional:
    case tcc_exceptional:
      {
      {
        tree phi = NULL;
        tree phi = NULL;
        edge e;
        edge e;
        gcc_assert (TREE_CODE (expr) == SSA_NAME);
        gcc_assert (TREE_CODE (expr) == SSA_NAME);
        if (TREE_CODE (SSA_NAME_DEF_STMT (expr)) == PHI_NODE)
        if (TREE_CODE (SSA_NAME_DEF_STMT (expr)) == PHI_NODE)
          phi = SSA_NAME_DEF_STMT (expr);
          phi = SSA_NAME_DEF_STMT (expr);
        else
        else
          return expr;
          return expr;
 
 
        e = find_edge (pred, bb_for_stmt (phi));
        e = find_edge (pred, bb_for_stmt (phi));
        if (e)
        if (e)
          {
          {
            if (is_undefined_value (PHI_ARG_DEF (phi, e->dest_idx)))
            if (is_undefined_value (PHI_ARG_DEF (phi, e->dest_idx)))
              return NULL;
              return NULL;
            vn_lookup_or_add (PHI_ARG_DEF (phi, e->dest_idx), NULL);
            vn_lookup_or_add (PHI_ARG_DEF (phi, e->dest_idx), NULL);
            return PHI_ARG_DEF (phi, e->dest_idx);
            return PHI_ARG_DEF (phi, e->dest_idx);
          }
          }
      }
      }
      return expr;
      return expr;
 
 
    default:
    default:
      gcc_unreachable ();
      gcc_unreachable ();
    }
    }
}
}
 
 
/* For each expression in SET, translate the value handles through phi nodes
/* For each expression in SET, translate the value handles through phi nodes
   in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
   in PHIBLOCK using edge PHIBLOCK->PRED, and store the resulting
   expressions in DEST.  */
   expressions in DEST.  */
 
 
static void
static void
phi_translate_set (value_set_t dest, value_set_t set, basic_block pred,
phi_translate_set (value_set_t dest, value_set_t set, basic_block pred,
                   basic_block phiblock)
                   basic_block phiblock)
{
{
  value_set_node_t node;
  value_set_node_t node;
  for (node = set->head;
  for (node = set->head;
       node;
       node;
       node = node->next)
       node = node->next)
    {
    {
      tree translated;
      tree translated;
 
 
      translated = phi_translate (node->expr, set, pred, phiblock);
      translated = phi_translate (node->expr, set, pred, phiblock);
 
 
      /* Don't add constants or empty translations to the cache, since
      /* Don't add constants or empty translations to the cache, since
         we won't look them up that way, or use the result, anyway.  */
         we won't look them up that way, or use the result, anyway.  */
      if (translated && !is_gimple_min_invariant (translated))
      if (translated && !is_gimple_min_invariant (translated))
        {
        {
          tree vh = get_value_handle (translated);
          tree vh = get_value_handle (translated);
          VEC (tree, gc) *vuses;
          VEC (tree, gc) *vuses;
 
 
          /* The value handle itself may also be an invariant, in
          /* The value handle itself may also be an invariant, in
             which case, it has no vuses.  */
             which case, it has no vuses.  */
          vuses = !is_gimple_min_invariant (vh)
          vuses = !is_gimple_min_invariant (vh)
            ? VALUE_HANDLE_VUSES (vh) : NULL;
            ? VALUE_HANDLE_VUSES (vh) : NULL;
          phi_trans_add (node->expr, translated, pred, vuses);
          phi_trans_add (node->expr, translated, pred, vuses);
        }
        }
 
 
      if (translated != NULL)
      if (translated != NULL)
        value_insert_into_set (dest, translated);
        value_insert_into_set (dest, translated);
    }
    }
}
}
 
 
/* Find the leader for a value (i.e., the name representing that
/* Find the leader for a value (i.e., the name representing that
   value) in a given set, and return it.  Return NULL if no leader is
   value) in a given set, and return it.  Return NULL if no leader is
   found.  */
   found.  */
 
 
static tree
static tree
bitmap_find_leader (bitmap_set_t set, tree val)
bitmap_find_leader (bitmap_set_t set, tree val)
{
{
  if (val == NULL)
  if (val == NULL)
    return NULL;
    return NULL;
 
 
  if (is_gimple_min_invariant (val))
  if (is_gimple_min_invariant (val))
    return val;
    return val;
  if (bitmap_set_contains_value (set, val))
  if (bitmap_set_contains_value (set, val))
    {
    {
      /* Rather than walk the entire bitmap of expressions, and see
      /* Rather than walk the entire bitmap of expressions, and see
         whether any of them has the value we are looking for, we look
         whether any of them has the value we are looking for, we look
         at the reverse mapping, which tells us the set of expressions
         at the reverse mapping, which tells us the set of expressions
         that have a given value (IE value->expressions with that
         that have a given value (IE value->expressions with that
         value) and see if any of those expressions are in our set.
         value) and see if any of those expressions are in our set.
         The number of expressions per value is usually significantly
         The number of expressions per value is usually significantly
         less than the number of expressions in the set.  In fact, for
         less than the number of expressions in the set.  In fact, for
         large testcases, doing it this way is roughly 5-10x faster
         large testcases, doing it this way is roughly 5-10x faster
         than walking the bitmap.
         than walking the bitmap.
         If this is somehow a significant lose for some cases, we can
         If this is somehow a significant lose for some cases, we can
         choose which set to walk based on which set is smaller.  */
         choose which set to walk based on which set is smaller.  */
      value_set_t exprset;
      value_set_t exprset;
      value_set_node_t node;
      value_set_node_t node;
      exprset = VALUE_HANDLE_EXPR_SET (val);
      exprset = VALUE_HANDLE_EXPR_SET (val);
      for (node = exprset->head; node; node = node->next)
      for (node = exprset->head; node; node = node->next)
        {
        {
          if (TREE_CODE (node->expr) == SSA_NAME)
          if (TREE_CODE (node->expr) == SSA_NAME)
            {
            {
              if (bitmap_bit_p (set->expressions,
              if (bitmap_bit_p (set->expressions,
                                SSA_NAME_VERSION (node->expr)))
                                SSA_NAME_VERSION (node->expr)))
                return node->expr;
                return node->expr;
            }
            }
        }
        }
    }
    }
  return NULL;
  return NULL;
}
}
 
 
 
 
/* Find the leader for a value (i.e., the name representing that
/* Find the leader for a value (i.e., the name representing that
   value) in a given set, and return it.  Return NULL if no leader is
   value) in a given set, and return it.  Return NULL if no leader is
   found.  */
   found.  */
 
 
static tree
static tree
find_leader (value_set_t set, tree val)
find_leader (value_set_t set, tree val)
{
{
  value_set_node_t node;
  value_set_node_t node;
 
 
  if (val == NULL)
  if (val == NULL)
    return NULL;
    return NULL;
 
 
  /* Constants represent themselves.  */
  /* Constants represent themselves.  */
  if (is_gimple_min_invariant (val))
  if (is_gimple_min_invariant (val))
    return val;
    return val;
 
 
  if (set->length == 0)
  if (set->length == 0)
    return NULL;
    return NULL;
 
 
  if (value_exists_in_set_bitmap (set, val))
  if (value_exists_in_set_bitmap (set, val))
    {
    {
      for (node = set->head;
      for (node = set->head;
           node;
           node;
           node = node->next)
           node = node->next)
        {
        {
          if (get_value_handle (node->expr) == val)
          if (get_value_handle (node->expr) == val)
            return node->expr;
            return node->expr;
        }
        }
    }
    }
 
 
  return NULL;
  return NULL;
}
}
 
 
/* Given the vuse representative map, MAP, and an SSA version number,
/* Given the vuse representative map, MAP, and an SSA version number,
   ID, return the bitmap of names ID represents, or NULL, if none
   ID, return the bitmap of names ID represents, or NULL, if none
   exists.  */
   exists.  */
 
 
static bitmap
static bitmap
get_representative (bitmap *map, int id)
get_representative (bitmap *map, int id)
{
{
  if (map[id] != NULL)
  if (map[id] != NULL)
    return map[id];
    return map[id];
  return NULL;
  return NULL;
}
}
 
 
/* A vuse is anticipable at the top of block x, from the bottom of the
/* A vuse is anticipable at the top of block x, from the bottom of the
   block, if it reaches the top of the block, and is not killed in the
   block, if it reaches the top of the block, and is not killed in the
   block.  In effect, we are trying to see if the vuse is transparent
   block.  In effect, we are trying to see if the vuse is transparent
   backwards in the block.  */
   backwards in the block.  */
 
 
static bool
static bool
vuses_dies_in_block_x (VEC (tree, gc) *vuses, basic_block block)
vuses_dies_in_block_x (VEC (tree, gc) *vuses, basic_block block)
{
{
  int i;
  int i;
  tree vuse;
  tree vuse;
 
 
  for (i = 0; VEC_iterate (tree, vuses, i, vuse); i++)
  for (i = 0; VEC_iterate (tree, vuses, i, vuse); i++)
    {
    {
      /* Any places where this is too conservative, are places
      /* Any places where this is too conservative, are places
         where we created a new version and shouldn't have.  */
         where we created a new version and shouldn't have.  */
 
 
      if (!bitmap_bit_p (RVUSE_IN (block), SSA_NAME_VERSION (vuse))
      if (!bitmap_bit_p (RVUSE_IN (block), SSA_NAME_VERSION (vuse))
          || bitmap_bit_p (RVUSE_KILL (block), SSA_NAME_VERSION (vuse)))
          || bitmap_bit_p (RVUSE_KILL (block), SSA_NAME_VERSION (vuse)))
        return true;
        return true;
    }
    }
  return false;
  return false;
}
}
 
 
/* Determine if the expression EXPR is valid in SET.  This means that
/* Determine if the expression EXPR is valid in SET.  This means that
   we have a leader for each part of the expression (if it consists of
   we have a leader for each part of the expression (if it consists of
   values), or the expression is an SSA_NAME.
   values), or the expression is an SSA_NAME.
 
 
   NB: We never should run into a case where we have SSA_NAME +
   NB: We never should run into a case where we have SSA_NAME +
   SSA_NAME or SSA_NAME + value.  The sets valid_in_set is called on,
   SSA_NAME or SSA_NAME + value.  The sets valid_in_set is called on,
   the ANTIC sets, will only ever have SSA_NAME's or value expressions
   the ANTIC sets, will only ever have SSA_NAME's or value expressions
   (IE VALUE1 + VALUE2, *VALUE1, VALUE1 < VALUE2)  */
   (IE VALUE1 + VALUE2, *VALUE1, VALUE1 < VALUE2)  */
 
 
static bool
static bool
valid_in_set (value_set_t set, tree expr, basic_block block)
valid_in_set (value_set_t set, tree expr, basic_block block)
{
{
 tree vh = get_value_handle (expr);
 tree vh = get_value_handle (expr);
 switch (TREE_CODE_CLASS (TREE_CODE (expr)))
 switch (TREE_CODE_CLASS (TREE_CODE (expr)))
    {
    {
    case tcc_binary:
    case tcc_binary:
    case tcc_comparison:
    case tcc_comparison:
      {
      {
        tree op1 = TREE_OPERAND (expr, 0);
        tree op1 = TREE_OPERAND (expr, 0);
        tree op2 = TREE_OPERAND (expr, 1);
        tree op2 = TREE_OPERAND (expr, 1);
        return set_contains_value (set, op1) && set_contains_value (set, op2);
        return set_contains_value (set, op1) && set_contains_value (set, op2);
      }
      }
 
 
    case tcc_unary:
    case tcc_unary:
      {
      {
        tree op1 = TREE_OPERAND (expr, 0);
        tree op1 = TREE_OPERAND (expr, 0);
        return set_contains_value (set, op1);
        return set_contains_value (set, op1);
      }
      }
 
 
    case tcc_expression:
    case tcc_expression:
      {
      {
        if (TREE_CODE (expr) == CALL_EXPR)
        if (TREE_CODE (expr) == CALL_EXPR)
          {
          {
            tree op0 = TREE_OPERAND (expr, 0);
            tree op0 = TREE_OPERAND (expr, 0);
            tree arglist = TREE_OPERAND (expr, 1);
            tree arglist = TREE_OPERAND (expr, 1);
            tree op2 = TREE_OPERAND (expr, 2);
            tree op2 = TREE_OPERAND (expr, 2);
 
 
            /* Check the non-list operands first.  */
            /* Check the non-list operands first.  */
            if (!set_contains_value (set, op0)
            if (!set_contains_value (set, op0)
                || (op2 && !set_contains_value (set, op2)))
                || (op2 && !set_contains_value (set, op2)))
              return false;
              return false;
 
 
            /* Now check the operands.  */
            /* Now check the operands.  */
            for (; arglist; arglist = TREE_CHAIN (arglist))
            for (; arglist; arglist = TREE_CHAIN (arglist))
              {
              {
                if (!set_contains_value (set, TREE_VALUE (arglist)))
                if (!set_contains_value (set, TREE_VALUE (arglist)))
                  return false;
                  return false;
              }
              }
            return !vuses_dies_in_block_x (VALUE_HANDLE_VUSES (vh), block);
            return !vuses_dies_in_block_x (VALUE_HANDLE_VUSES (vh), block);
          }
          }
        return false;
        return false;
      }
      }
 
 
    case tcc_reference:
    case tcc_reference:
      {
      {
        if (TREE_CODE (expr) == INDIRECT_REF
        if (TREE_CODE (expr) == INDIRECT_REF
            || TREE_CODE (expr) == COMPONENT_REF
            || TREE_CODE (expr) == COMPONENT_REF
            || TREE_CODE (expr) == ARRAY_REF)
            || TREE_CODE (expr) == ARRAY_REF)
          {
          {
            tree op0 = TREE_OPERAND (expr, 0);
            tree op0 = TREE_OPERAND (expr, 0);
            gcc_assert (is_gimple_min_invariant (op0)
            gcc_assert (is_gimple_min_invariant (op0)
                        || TREE_CODE (op0) == VALUE_HANDLE);
                        || TREE_CODE (op0) == VALUE_HANDLE);
            if (!set_contains_value (set, op0))
            if (!set_contains_value (set, op0))
              return false;
              return false;
            if (TREE_CODE (expr) == ARRAY_REF)
            if (TREE_CODE (expr) == ARRAY_REF)
              {
              {
                tree op1 = TREE_OPERAND (expr, 1);
                tree op1 = TREE_OPERAND (expr, 1);
                tree op2 = TREE_OPERAND (expr, 2);
                tree op2 = TREE_OPERAND (expr, 2);
                tree op3 = TREE_OPERAND (expr, 3);
                tree op3 = TREE_OPERAND (expr, 3);
                gcc_assert (is_gimple_min_invariant (op1)
                gcc_assert (is_gimple_min_invariant (op1)
                            || TREE_CODE (op1) == VALUE_HANDLE);
                            || TREE_CODE (op1) == VALUE_HANDLE);
                if (!set_contains_value (set, op1))
                if (!set_contains_value (set, op1))
                  return false;
                  return false;
                gcc_assert (!op2 || is_gimple_min_invariant (op2)
                gcc_assert (!op2 || is_gimple_min_invariant (op2)
                            || TREE_CODE (op2) == VALUE_HANDLE);
                            || TREE_CODE (op2) == VALUE_HANDLE);
                if (op2
                if (op2
                    && !set_contains_value (set, op2))
                    && !set_contains_value (set, op2))
                  return false;
                  return false;
                gcc_assert (!op3 || is_gimple_min_invariant (op3)
                gcc_assert (!op3 || is_gimple_min_invariant (op3)
                            || TREE_CODE (op3) == VALUE_HANDLE);
                            || TREE_CODE (op3) == VALUE_HANDLE);
                if (op3
                if (op3
                    && !set_contains_value (set, op3))
                    && !set_contains_value (set, op3))
                  return false;
                  return false;
            }
            }
          return set_contains_value (ANTIC_SAFE_LOADS (block),
          return set_contains_value (ANTIC_SAFE_LOADS (block),
                                     vh)
                                     vh)
            || !vuses_dies_in_block_x (VALUE_HANDLE_VUSES (vh),
            || !vuses_dies_in_block_x (VALUE_HANDLE_VUSES (vh),
                                       block);
                                       block);
          }
          }
      }
      }
      return false;
      return false;
 
 
    case tcc_exceptional:
    case tcc_exceptional:
      gcc_assert (TREE_CODE (expr) == SSA_NAME);
      gcc_assert (TREE_CODE (expr) == SSA_NAME);
      return true;
      return true;
 
 
    case tcc_declaration:
    case tcc_declaration:
      return !vuses_dies_in_block_x (VALUE_HANDLE_VUSES (vh), block);
      return !vuses_dies_in_block_x (VALUE_HANDLE_VUSES (vh), block);
 
 
    default:
    default:
      /* No other cases should be encountered.  */
      /* No other cases should be encountered.  */
      gcc_unreachable ();
      gcc_unreachable ();
   }
   }
}
}
 
 
/* Clean the set of expressions that are no longer valid in SET.  This
/* Clean the set of expressions that are no longer valid in SET.  This
   means expressions that are made up of values we have no leaders for
   means expressions that are made up of values we have no leaders for
   in SET.  */
   in SET.  */
 
 
static void
static void
clean (value_set_t set, basic_block block)
clean (value_set_t set, basic_block block)
{
{
  value_set_node_t node;
  value_set_node_t node;
  value_set_node_t next;
  value_set_node_t next;
  node = set->head;
  node = set->head;
  while (node)
  while (node)
    {
    {
      next = node->next;
      next = node->next;
      if (!valid_in_set (set, node->expr, block))
      if (!valid_in_set (set, node->expr, block))
        set_remove (set, node->expr);
        set_remove (set, node->expr);
      node = next;
      node = next;
    }
    }
}
}
 
 
static sbitmap has_abnormal_preds;
static sbitmap has_abnormal_preds;
 
 
/* Compute the ANTIC set for BLOCK.
/* Compute the ANTIC set for BLOCK.
 
 
   If succs(BLOCK) > 1 then
   If succs(BLOCK) > 1 then
     ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
     ANTIC_OUT[BLOCK] = intersection of ANTIC_IN[b] for all succ(BLOCK)
   else if succs(BLOCK) == 1 then
   else if succs(BLOCK) == 1 then
     ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
     ANTIC_OUT[BLOCK] = phi_translate (ANTIC_IN[succ(BLOCK)])
 
 
   ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
   ANTIC_IN[BLOCK] = clean(ANTIC_OUT[BLOCK] U EXP_GEN[BLOCK] - TMP_GEN[BLOCK])
 
 
   XXX: It would be nice to either write a set_clear, and use it for
   XXX: It would be nice to either write a set_clear, and use it for
   ANTIC_OUT, or to mark the antic_out set as deleted at the end
   ANTIC_OUT, or to mark the antic_out set as deleted at the end
   of this routine, so that the pool can hand the same memory back out
   of this routine, so that the pool can hand the same memory back out
   again for the next ANTIC_OUT.  */
   again for the next ANTIC_OUT.  */
 
 
static bool
static bool
compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge)
compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge)
{
{
  basic_block son;
  basic_block son;
  bool changed = false;
  bool changed = false;
  value_set_t S, old, ANTIC_OUT;
  value_set_t S, old, ANTIC_OUT;
  value_set_node_t node;
  value_set_node_t node;
 
 
  ANTIC_OUT = S = NULL;
  ANTIC_OUT = S = NULL;
 
 
  /* If any edges from predecessors are abnormal, antic_in is empty,
  /* If any edges from predecessors are abnormal, antic_in is empty,
     so do nothing.  */
     so do nothing.  */
  if (block_has_abnormal_pred_edge)
  if (block_has_abnormal_pred_edge)
    goto maybe_dump_sets;
    goto maybe_dump_sets;
 
 
  old = set_new (false);
  old = set_new (false);
  set_copy (old, ANTIC_IN (block));
  set_copy (old, ANTIC_IN (block));
  ANTIC_OUT = set_new (true);
  ANTIC_OUT = set_new (true);
 
 
  /* If the block has no successors, ANTIC_OUT is empty.  */
  /* If the block has no successors, ANTIC_OUT is empty.  */
  if (EDGE_COUNT (block->succs) == 0)
  if (EDGE_COUNT (block->succs) == 0)
    ;
    ;
  /* If we have one successor, we could have some phi nodes to
  /* If we have one successor, we could have some phi nodes to
     translate through.  */
     translate through.  */
  else if (single_succ_p (block))
  else if (single_succ_p (block))
    {
    {
      phi_translate_set (ANTIC_OUT, ANTIC_IN (single_succ (block)),
      phi_translate_set (ANTIC_OUT, ANTIC_IN (single_succ (block)),
                         block, single_succ (block));
                         block, single_succ (block));
    }
    }
  /* If we have multiple successors, we take the intersection of all of
  /* If we have multiple successors, we take the intersection of all of
     them.  */
     them.  */
  else
  else
    {
    {
      VEC(basic_block, heap) * worklist;
      VEC(basic_block, heap) * worklist;
      edge e;
      edge e;
      size_t i;
      size_t i;
      basic_block bprime, first;
      basic_block bprime, first;
      edge_iterator ei;
      edge_iterator ei;
 
 
      worklist = VEC_alloc (basic_block, heap, EDGE_COUNT (block->succs));
      worklist = VEC_alloc (basic_block, heap, EDGE_COUNT (block->succs));
      FOR_EACH_EDGE (e, ei, block->succs)
      FOR_EACH_EDGE (e, ei, block->succs)
        VEC_quick_push (basic_block, worklist, e->dest);
        VEC_quick_push (basic_block, worklist, e->dest);
      first = VEC_index (basic_block, worklist, 0);
      first = VEC_index (basic_block, worklist, 0);
      set_copy (ANTIC_OUT, ANTIC_IN (first));
      set_copy (ANTIC_OUT, ANTIC_IN (first));
 
 
      for (i = 1; VEC_iterate (basic_block, worklist, i, bprime); i++)
      for (i = 1; VEC_iterate (basic_block, worklist, i, bprime); i++)
        {
        {
          node = ANTIC_OUT->head;
          node = ANTIC_OUT->head;
          while (node)
          while (node)
            {
            {
              tree val;
              tree val;
              value_set_node_t next = node->next;
              value_set_node_t next = node->next;
 
 
              val = get_value_handle (node->expr);
              val = get_value_handle (node->expr);
              if (!set_contains_value (ANTIC_IN (bprime), val))
              if (!set_contains_value (ANTIC_IN (bprime), val))
                set_remove (ANTIC_OUT, node->expr);
                set_remove (ANTIC_OUT, node->expr);
              node = next;
              node = next;
            }
            }
        }
        }
      VEC_free (basic_block, heap, worklist);
      VEC_free (basic_block, heap, worklist);
    }
    }
 
 
  /* Generate ANTIC_OUT - TMP_GEN.  */
  /* Generate ANTIC_OUT - TMP_GEN.  */
  S = bitmap_set_subtract_from_value_set (ANTIC_OUT, TMP_GEN (block), false);
  S = bitmap_set_subtract_from_value_set (ANTIC_OUT, TMP_GEN (block), false);
 
 
  /* Start ANTIC_IN with EXP_GEN - TMP_GEN */
  /* Start ANTIC_IN with EXP_GEN - TMP_GEN */
  ANTIC_IN (block) = bitmap_set_subtract_from_value_set (EXP_GEN (block),
  ANTIC_IN (block) = bitmap_set_subtract_from_value_set (EXP_GEN (block),
                                                         TMP_GEN (block),
                                                         TMP_GEN (block),
                                                         true);
                                                         true);
 
 
  /* Then union in the ANTIC_OUT - TMP_GEN values,
  /* Then union in the ANTIC_OUT - TMP_GEN values,
     to get ANTIC_OUT U EXP_GEN - TMP_GEN */
     to get ANTIC_OUT U EXP_GEN - TMP_GEN */
  for (node = S->head; node; node = node->next)
  for (node = S->head; node; node = node->next)
    value_insert_into_set (ANTIC_IN (block), node->expr);
    value_insert_into_set (ANTIC_IN (block), node->expr);
 
 
  clean (ANTIC_IN (block), block);
  clean (ANTIC_IN (block), block);
  if (!set_equal (old, ANTIC_IN (block)))
  if (!set_equal (old, ANTIC_IN (block)))
    changed = true;
    changed = true;
 
 
 maybe_dump_sets:
 maybe_dump_sets:
  if (dump_file && (dump_flags & TDF_DETAILS))
  if (dump_file && (dump_flags & TDF_DETAILS))
    {
    {
      if (ANTIC_OUT)
      if (ANTIC_OUT)
        print_value_set (dump_file, ANTIC_OUT, "ANTIC_OUT", block->index);
        print_value_set (dump_file, ANTIC_OUT, "ANTIC_OUT", block->index);
 
 
      if (ANTIC_SAFE_LOADS (block))
      if (ANTIC_SAFE_LOADS (block))
        print_value_set (dump_file, ANTIC_SAFE_LOADS (block),
        print_value_set (dump_file, ANTIC_SAFE_LOADS (block),
                         "ANTIC_SAFE_LOADS", block->index);
                         "ANTIC_SAFE_LOADS", block->index);
      print_value_set (dump_file, ANTIC_IN (block), "ANTIC_IN", block->index);
      print_value_set (dump_file, ANTIC_IN (block), "ANTIC_IN", block->index);
 
 
      if (S)
      if (S)
        print_value_set (dump_file, S, "S", block->index);
        print_value_set (dump_file, S, "S", block->index);
    }
    }
 
 
  for (son = first_dom_son (CDI_POST_DOMINATORS, block);
  for (son = first_dom_son (CDI_POST_DOMINATORS, block);
       son;
       son;
       son = next_dom_son (CDI_POST_DOMINATORS, son))
       son = next_dom_son (CDI_POST_DOMINATORS, son))
    {
    {
      changed |= compute_antic_aux (son,
      changed |= compute_antic_aux (son,
                                    TEST_BIT (has_abnormal_preds, son->index));
                                    TEST_BIT (has_abnormal_preds, son->index));
    }
    }
  return changed;
  return changed;
}
}
 
 
/* Compute ANTIC sets.  */
/* Compute ANTIC sets.  */
 
 
static void
static void
compute_antic (void)
compute_antic (void)
{
{
  bool changed = true;
  bool changed = true;
  int num_iterations = 0;
  int num_iterations = 0;
  basic_block block;
  basic_block block;
 
 
  /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
  /* If any predecessor edges are abnormal, we punt, so antic_in is empty.
     We pre-build the map of blocks with incoming abnormal edges here.  */
     We pre-build the map of blocks with incoming abnormal edges here.  */
  has_abnormal_preds = sbitmap_alloc (last_basic_block);
  has_abnormal_preds = sbitmap_alloc (last_basic_block);
  sbitmap_zero (has_abnormal_preds);
  sbitmap_zero (has_abnormal_preds);
  FOR_EACH_BB (block)
  FOR_EACH_BB (block)
    {
    {
      edge_iterator ei;
      edge_iterator ei;
      edge e;
      edge e;
 
 
      FOR_EACH_EDGE (e, ei, block->preds)
      FOR_EACH_EDGE (e, ei, block->preds)
        if (e->flags & EDGE_ABNORMAL)
        if (e->flags & EDGE_ABNORMAL)
          {
          {
            SET_BIT (has_abnormal_preds, block->index);
            SET_BIT (has_abnormal_preds, block->index);
            break;
            break;
          }
          }
 
 
      /* While we are here, give empty ANTIC_IN sets to each block.  */
      /* While we are here, give empty ANTIC_IN sets to each block.  */
      ANTIC_IN (block) = set_new (true);
      ANTIC_IN (block) = set_new (true);
    }
    }
  /* At the exit block we anticipate nothing.  */
  /* At the exit block we anticipate nothing.  */
  ANTIC_IN (EXIT_BLOCK_PTR) = set_new (true);
  ANTIC_IN (EXIT_BLOCK_PTR) = set_new (true);
 
 
  while (changed)
  while (changed)
    {
    {
      num_iterations++;
      num_iterations++;
      changed = false;
      changed = false;
      changed = compute_antic_aux (EXIT_BLOCK_PTR, false);
      changed = compute_antic_aux (EXIT_BLOCK_PTR, false);
    }
    }
 
 
  sbitmap_free (has_abnormal_preds);
  sbitmap_free (has_abnormal_preds);
 
 
  if (dump_file && (dump_flags & TDF_STATS))
  if (dump_file && (dump_flags & TDF_STATS))
    fprintf (dump_file, "compute_antic required %d iterations\n", num_iterations);
    fprintf (dump_file, "compute_antic required %d iterations\n", num_iterations);
}
}
 
 
/* Print the names represented by the bitmap NAMES, to the file OUT.  */
/* Print the names represented by the bitmap NAMES, to the file OUT.  */
static void
static void
dump_bitmap_of_names (FILE *out, bitmap names)
dump_bitmap_of_names (FILE *out, bitmap names)
{
{
  bitmap_iterator bi;
  bitmap_iterator bi;
  unsigned int i;
  unsigned int i;
 
 
  fprintf (out, " { ");
  fprintf (out, " { ");
  EXECUTE_IF_SET_IN_BITMAP (names, 0, i, bi)
  EXECUTE_IF_SET_IN_BITMAP (names, 0, i, bi)
    {
    {
      print_generic_expr (out, ssa_name (i), 0);
      print_generic_expr (out, ssa_name (i), 0);
      fprintf (out, " ");
      fprintf (out, " ");
    }
    }
  fprintf (out, "}\n");
  fprintf (out, "}\n");
}
}
 
 
  /* Compute a set of representative vuse versions for each phi.  This
  /* Compute a set of representative vuse versions for each phi.  This
     is so we can compute conservative kill sets in terms of all vuses
     is so we can compute conservative kill sets in terms of all vuses
     that are killed, instead of continually walking chains.
     that are killed, instead of continually walking chains.
 
 
     We also have to be able kill all names associated with a phi when
     We also have to be able kill all names associated with a phi when
     the phi dies in order to ensure we don't generate overlapping
     the phi dies in order to ensure we don't generate overlapping
     live ranges, which are not allowed in virtual SSA.  */
     live ranges, which are not allowed in virtual SSA.  */
 
 
static bitmap *vuse_names;
static bitmap *vuse_names;
static void
static void
compute_vuse_representatives (void)
compute_vuse_representatives (void)
{
{
  tree phi;
  tree phi;
  basic_block bb;
  basic_block bb;
  VEC (tree, heap) *phis = NULL;
  VEC (tree, heap) *phis = NULL;
  bool changed = true;
  bool changed = true;
  size_t i;
  size_t i;
 
 
  FOR_EACH_BB (bb)
  FOR_EACH_BB (bb)
    {
    {
      for (phi = phi_nodes (bb);
      for (phi = phi_nodes (bb);
           phi;
           phi;
           phi = PHI_CHAIN (phi))
           phi = PHI_CHAIN (phi))
        if (!is_gimple_reg (PHI_RESULT (phi)))
        if (!is_gimple_reg (PHI_RESULT (phi)))
          VEC_safe_push (tree, heap, phis, phi);
          VEC_safe_push (tree, heap, phis, phi);
    }
    }
 
 
  while (changed)
  while (changed)
    {
    {
      changed = false;
      changed = false;
 
 
      for (i = 0; VEC_iterate (tree, phis, i, phi); i++)
      for (i = 0; VEC_iterate (tree, phis, i, phi); i++)
        {
        {
          size_t ver = SSA_NAME_VERSION (PHI_RESULT (phi));
          size_t ver = SSA_NAME_VERSION (PHI_RESULT (phi));
          use_operand_p usep;
          use_operand_p usep;
          ssa_op_iter iter;
          ssa_op_iter iter;
 
 
          if (vuse_names[ver] == NULL)
          if (vuse_names[ver] == NULL)
            {
            {
              vuse_names[ver] = BITMAP_ALLOC (&grand_bitmap_obstack);
              vuse_names[ver] = BITMAP_ALLOC (&grand_bitmap_obstack);
              bitmap_set_bit (vuse_names[ver], ver);
              bitmap_set_bit (vuse_names[ver], ver);
            }
            }
          FOR_EACH_PHI_ARG (usep, phi, iter, SSA_OP_ALL_USES)
          FOR_EACH_PHI_ARG (usep, phi, iter, SSA_OP_ALL_USES)
            {
            {
              tree use = USE_FROM_PTR (usep);
              tree use = USE_FROM_PTR (usep);
              bitmap usebitmap = get_representative (vuse_names,
              bitmap usebitmap = get_representative (vuse_names,
                                                     SSA_NAME_VERSION (use));
                                                     SSA_NAME_VERSION (use));
              if (usebitmap != NULL)
              if (usebitmap != NULL)
                {
                {
                  changed |= bitmap_ior_into (vuse_names[ver],
                  changed |= bitmap_ior_into (vuse_names[ver],
                                              usebitmap);
                                              usebitmap);
                }
                }
              else
              else
                {
                {
                  changed |= !bitmap_bit_p (vuse_names[ver],
                  changed |= !bitmap_bit_p (vuse_names[ver],
                                            SSA_NAME_VERSION (use));
                                            SSA_NAME_VERSION (use));
                  if (changed)
                  if (changed)
                    bitmap_set_bit (vuse_names[ver],
                    bitmap_set_bit (vuse_names[ver],
                                    SSA_NAME_VERSION (use));
                                    SSA_NAME_VERSION (use));
                }
                }
            }
            }
        }
        }
    }
    }
 
 
  if (dump_file && (dump_flags & TDF_DETAILS))
  if (dump_file && (dump_flags & TDF_DETAILS))
    for (i = 0; VEC_iterate (tree, phis, i, phi); i++)
    for (i = 0; VEC_iterate (tree, phis, i, phi); i++)
      {
      {
        bitmap reps = get_representative (vuse_names,
        bitmap reps = get_representative (vuse_names,
                                          SSA_NAME_VERSION (PHI_RESULT (phi)));
                                          SSA_NAME_VERSION (PHI_RESULT (phi)));
        if (reps)
        if (reps)
          {
          {
            print_generic_expr (dump_file, PHI_RESULT (phi), 0);
            print_generic_expr (dump_file, PHI_RESULT (phi), 0);
            fprintf (dump_file, " represents ");
            fprintf (dump_file, " represents ");
            dump_bitmap_of_names (dump_file, reps);
            dump_bitmap_of_names (dump_file, reps);
          }
          }
      }
      }
  VEC_free (tree, heap, phis);
  VEC_free (tree, heap, phis);
}
}
 
 
/* Compute reaching vuses and antic safe loads.  RVUSE computation is
/* Compute reaching vuses and antic safe loads.  RVUSE computation is
   is a small bit of iterative dataflow to determine what virtual uses
   is a small bit of iterative dataflow to determine what virtual uses
   reach what blocks.  Because we can't generate overlapping virtual
   reach what blocks.  Because we can't generate overlapping virtual
   uses, and virtual uses *do* actually die, this ends up being faster
   uses, and virtual uses *do* actually die, this ends up being faster
   in most cases than continually walking the virtual use/def chains
   in most cases than continually walking the virtual use/def chains
   to determine whether we are inside a block where a given virtual is
   to determine whether we are inside a block where a given virtual is
   still available to be used.
   still available to be used.
 
 
   ANTIC_SAFE_LOADS are those loads that actually occur before any kill to
   ANTIC_SAFE_LOADS are those loads that actually occur before any kill to
   their vuses in the block,and thus, are safe at the top of the
   their vuses in the block,and thus, are safe at the top of the
   block.
   block.
 
 
   An example:
   An example:
 
 
   <block begin>
   <block begin>
   b = *a
   b = *a
   *a = 9
   *a = 9
   <block end>
   <block end>
 
 
   b = *a is an antic safe load because it still safe to consider it
   b = *a is an antic safe load because it still safe to consider it
   ANTIC at the top of the block.
   ANTIC at the top of the block.
 
 
   We currently compute a conservative approximation to
   We currently compute a conservative approximation to
   ANTIC_SAFE_LOADS.  We compute those loads that occur before *any*
   ANTIC_SAFE_LOADS.  We compute those loads that occur before *any*
   stores in the block.  This is not because it is difficult to
   stores in the block.  This is not because it is difficult to
   compute the precise answer, but because it is expensive.  More
   compute the precise answer, but because it is expensive.  More
   testing is necessary to determine whether it is worth computing the
   testing is necessary to determine whether it is worth computing the
   precise answer.  */
   precise answer.  */
 
 
static void
static void
compute_rvuse_and_antic_safe (void)
compute_rvuse_and_antic_safe (void)
{
{
 
 
  size_t i;
  size_t i;
  tree phi;
  tree phi;
  basic_block bb;
  basic_block bb;
  int *postorder;
  int *postorder;
  bool changed = true;
  bool changed = true;
  unsigned int *first_store_uid;
  unsigned int *first_store_uid;
 
 
  first_store_uid = xcalloc (n_basic_blocks, sizeof (unsigned int));
  first_store_uid = xcalloc (n_basic_blocks, sizeof (unsigned int));
 
 
  compute_vuse_representatives ();
  compute_vuse_representatives ();
 
 
  FOR_ALL_BB (bb)
  FOR_ALL_BB (bb)
    {
    {
      RVUSE_IN (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
      RVUSE_IN (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
      RVUSE_GEN (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
      RVUSE_GEN (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
      RVUSE_KILL (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
      RVUSE_KILL (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
      RVUSE_OUT (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
      RVUSE_OUT (bb) = BITMAP_ALLOC (&grand_bitmap_obstack);
      ANTIC_SAFE_LOADS (bb) = NULL;
      ANTIC_SAFE_LOADS (bb) = NULL;
    }
    }
 
 
  /* Mark live on entry */
  /* Mark live on entry */
  for (i = 0; i < num_ssa_names; i++)
  for (i = 0; i < num_ssa_names; i++)
    {
    {
      tree name = ssa_name (i);
      tree name = ssa_name (i);
      if (name && !is_gimple_reg (name)
      if (name && !is_gimple_reg (name)
          && IS_EMPTY_STMT (SSA_NAME_DEF_STMT (name)))
          && IS_EMPTY_STMT (SSA_NAME_DEF_STMT (name)))
        bitmap_set_bit (RVUSE_OUT (ENTRY_BLOCK_PTR),
        bitmap_set_bit (RVUSE_OUT (ENTRY_BLOCK_PTR),
                        SSA_NAME_VERSION (name));
                        SSA_NAME_VERSION (name));
    }
    }
 
 
  /* Compute local sets for reaching vuses.
  /* Compute local sets for reaching vuses.
     GEN(block) = generated in block and not locally killed.
     GEN(block) = generated in block and not locally killed.
     KILL(block) = set of vuses killed in block.
     KILL(block) = set of vuses killed in block.
  */
  */
 
 
  FOR_EACH_BB (bb)
  FOR_EACH_BB (bb)
    {
    {
      block_stmt_iterator bsi;
      block_stmt_iterator bsi;
      ssa_op_iter iter;
      ssa_op_iter iter;
      def_operand_p defp;
      def_operand_p defp;
      use_operand_p usep;
      use_operand_p usep;
 
 
      for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
      for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
        {
        {
          tree stmt = bsi_stmt (bsi);
          tree stmt = bsi_stmt (bsi);
 
 
          if (first_store_uid[bb->index] == 0
          if (first_store_uid[bb->index] == 0
              && !ZERO_SSA_OPERANDS (stmt, SSA_OP_VMAYUSE | SSA_OP_VMAYDEF
              && !ZERO_SSA_OPERANDS (stmt, SSA_OP_VMAYUSE | SSA_OP_VMAYDEF
                                     | SSA_OP_VMUSTDEF | SSA_OP_VMUSTKILL))
                                     | SSA_OP_VMUSTDEF | SSA_OP_VMUSTKILL))
            {
            {
              first_store_uid[bb->index] = stmt_ann (stmt)->uid;
              first_store_uid[bb->index] = stmt_ann (stmt)->uid;
            }
            }
 
 
 
 
          FOR_EACH_SSA_USE_OPERAND (usep, stmt, iter, SSA_OP_VIRTUAL_KILLS
          FOR_EACH_SSA_USE_OPERAND (usep, stmt, iter, SSA_OP_VIRTUAL_KILLS
                                    | SSA_OP_VMAYUSE)
                                    | SSA_OP_VMAYUSE)
            {
            {
              tree use = USE_FROM_PTR (usep);
              tree use = USE_FROM_PTR (usep);
              bitmap repbit = get_representative (vuse_names,
              bitmap repbit = get_representative (vuse_names,
                                                  SSA_NAME_VERSION (use));
                                                  SSA_NAME_VERSION (use));
              if (repbit != NULL)
              if (repbit != NULL)
                {
                {
                  bitmap_and_compl_into (RVUSE_GEN (bb), repbit);
                  bitmap_and_compl_into (RVUSE_GEN (bb), repbit);
                  bitmap_ior_into (RVUSE_KILL (bb), repbit);
                  bitmap_ior_into (RVUSE_KILL (bb), repbit);
                }
                }
              else
              else
                {
                {
                  bitmap_set_bit (RVUSE_KILL (bb), SSA_NAME_VERSION (use));
                  bitmap_set_bit (RVUSE_KILL (bb), SSA_NAME_VERSION (use));
                  bitmap_clear_bit (RVUSE_GEN (bb), SSA_NAME_VERSION (use));
                  bitmap_clear_bit (RVUSE_GEN (bb), SSA_NAME_VERSION (use));
                }
                }
            }
            }
          FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_VIRTUAL_DEFS)
          FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_VIRTUAL_DEFS)
            {
            {
              tree def = DEF_FROM_PTR (defp);
              tree def = DEF_FROM_PTR (defp);
              bitmap_set_bit (RVUSE_GEN (bb), SSA_NAME_VERSION (def));
              bitmap_set_bit (RVUSE_GEN (bb), SSA_NAME_VERSION (def));
            }
            }
        }
        }
    }
    }
 
 
  FOR_EACH_BB (bb)
  FOR_EACH_BB (bb)
    {
    {
      for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
      for (phi = phi_nodes (bb); phi; phi = PHI_CHAIN (phi))
        {
        {
          if (!is_gimple_reg (PHI_RESULT (phi)))
          if (!is_gimple_reg (PHI_RESULT (phi)))
            {
            {
              edge e;
              edge e;
              edge_iterator ei;
              edge_iterator ei;
 
 
              tree def = PHI_RESULT (phi);
              tree def = PHI_RESULT (phi);
              /* In reality, the PHI result is generated at the end of
              /* In reality, the PHI result is generated at the end of
                 each predecessor block.  This will make the value
                 each predecessor block.  This will make the value
                 LVUSE_IN for the bb containing the PHI, which is
                 LVUSE_IN for the bb containing the PHI, which is
                 correct.  */
                 correct.  */
              FOR_EACH_EDGE (e, ei, bb->preds)
              FOR_EACH_EDGE (e, ei, bb->preds)
                bitmap_set_bit (RVUSE_GEN (e->src), SSA_NAME_VERSION (def));
                bitmap_set_bit (RVUSE_GEN (e->src), SSA_NAME_VERSION (def));
            }
            }
        }
        }
    }
    }
 
 
  /* Solve reaching vuses.
  /* Solve reaching vuses.
 
 
     RVUSE_IN[BB] = Union of RVUSE_OUT of predecessors.
     RVUSE_IN[BB] = Union of RVUSE_OUT of predecessors.
     RVUSE_OUT[BB] = RVUSE_GEN[BB] U (RVUSE_IN[BB] - RVUSE_KILL[BB])
     RVUSE_OUT[BB] = RVUSE_GEN[BB] U (RVUSE_IN[BB] - RVUSE_KILL[BB])
  */
  */
  postorder = XNEWVEC (int, n_basic_blocks - NUM_FIXED_BLOCKS);
  postorder = XNEWVEC (int, n_basic_blocks - NUM_FIXED_BLOCKS);
  pre_and_rev_post_order_compute (NULL, postorder, false);
  pre_and_rev_post_order_compute (NULL, postorder, false);
 
 
  changed = true;
  changed = true;
  while (changed)
  while (changed)
    {
    {
      int j;
      int j;
      changed = false;
      changed = false;
      for (j = 0; j < n_basic_blocks - NUM_FIXED_BLOCKS; j++)
      for (j = 0; j < n_basic_blocks - NUM_FIXED_BLOCKS; j++)
        {
        {
          edge e;
          edge e;
          edge_iterator ei;
          edge_iterator ei;
          bb = BASIC_BLOCK (postorder[j]);
          bb = BASIC_BLOCK (postorder[j]);
 
 
          FOR_EACH_EDGE (e, ei, bb->preds)
          FOR_EACH_EDGE (e, ei, bb->preds)
            bitmap_ior_into (RVUSE_IN (bb), RVUSE_OUT (e->src));
            bitmap_ior_into (RVUSE_IN (bb), RVUSE_OUT (e->src));
 
 
          changed |= bitmap_ior_and_compl (RVUSE_OUT (bb),
          changed |= bitmap_ior_and_compl (RVUSE_OUT (bb),
                                           RVUSE_GEN (bb),
                                           RVUSE_GEN (bb),
                                           RVUSE_IN (bb),
                                           RVUSE_IN (bb),
                                           RVUSE_KILL (bb));
                                           RVUSE_KILL (bb));
        }
        }
    }
    }
  free (postorder);
  free (postorder);
 
 
  if (dump_file && (dump_flags & TDF_DETAILS))
  if (dump_file && (dump_flags & TDF_DETAILS))
    {
    {
      FOR_ALL_BB (bb)
      FOR_ALL_BB (bb)
        {
        {
          fprintf (dump_file, "RVUSE_IN (%d) =", bb->index);
          fprintf (dump_file, "RVUSE_IN (%d) =", bb->index);
          dump_bitmap_of_names (dump_file, RVUSE_IN (bb));
          dump_bitmap_of_names (dump_file, RVUSE_IN (bb));
 
 
          fprintf (dump_file, "RVUSE_KILL (%d) =", bb->index);
          fprintf (dump_file, "RVUSE_KILL (%d) =", bb->index);
          dump_bitmap_of_names (dump_file, RVUSE_KILL (bb));
          dump_bitmap_of_names (dump_file, RVUSE_KILL (bb));
 
 
          fprintf (dump_file, "RVUSE_GEN (%d) =", bb->index);
          fprintf (dump_file, "RVUSE_GEN (%d) =", bb->index);
          dump_bitmap_of_names (dump_file, RVUSE_GEN (bb));
          dump_bitmap_of_names (dump_file, RVUSE_GEN (bb));
 
 
          fprintf (dump_file, "RVUSE_OUT (%d) =", bb->index);
          fprintf (dump_file, "RVUSE_OUT (%d) =", bb->index);
          dump_bitmap_of_names (dump_file, RVUSE_OUT (bb));
          dump_bitmap_of_names (dump_file, RVUSE_OUT (bb));
        }
        }
    }
    }
 
 
  FOR_EACH_BB (bb)
  FOR_EACH_BB (bb)
    {
    {
      value_set_node_t node;
      value_set_node_t node;
      if (bitmap_empty_p (RVUSE_KILL (bb)))
      if (bitmap_empty_p (RVUSE_KILL (bb)))
        continue;
        continue;
 
 
      for (node = EXP_GEN (bb)->head; node; node = node->next)
      for (node = EXP_GEN (bb)->head; node; node = node->next)
        {
        {
          if (REFERENCE_CLASS_P (node->expr))
          if (REFERENCE_CLASS_P (node->expr))
            {
            {
              tree vh = get_value_handle (node->expr);
              tree vh = get_value_handle (node->expr);
              tree maybe = bitmap_find_leader (AVAIL_OUT (bb), vh);
              tree maybe = bitmap_find_leader (AVAIL_OUT (bb), vh);
 
 
              if (maybe)
              if (maybe)
                {
                {
                  tree def = SSA_NAME_DEF_STMT (maybe);
                  tree def = SSA_NAME_DEF_STMT (maybe);
 
 
                  if (bb_for_stmt (def) != bb)
                  if (bb_for_stmt (def) != bb)
                    continue;
                    continue;
 
 
                  if (TREE_CODE (def) == PHI_NODE
                  if (TREE_CODE (def) == PHI_NODE
                      || stmt_ann (def)->uid < first_store_uid[bb->index])
                      || stmt_ann (def)->uid < first_store_uid[bb->index])
                    {
                    {
                      if (ANTIC_SAFE_LOADS (bb) == NULL)
                      if (ANTIC_SAFE_LOADS (bb) == NULL)
                        ANTIC_SAFE_LOADS (bb) = set_new (true);
                        ANTIC_SAFE_LOADS (bb) = set_new (true);
                      value_insert_into_set (ANTIC_SAFE_LOADS (bb),
                      value_insert_into_set (ANTIC_SAFE_LOADS (bb),
                                             node->expr);
                                             node->expr);
                    }
                    }
                }
                }
            }
            }
        }
        }
    }
    }
  free (first_store_uid);
  free (first_store_uid);
}
}
 
 
/* Return true if we can value number the call in STMT.  This is true
/* Return true if we can value number the call in STMT.  This is true
   if we have a pure or constant call.  */
   if we have a pure or constant call.  */
 
 
static bool
static bool
can_value_number_call (tree stmt)
can_value_number_call (tree stmt)
{
{
  tree call = get_call_expr_in (stmt);
  tree call = get_call_expr_in (stmt);
 
 
  if (call_expr_flags (call)  & (ECF_PURE | ECF_CONST))
  if (call_expr_flags (call)  & (ECF_PURE | ECF_CONST))
    return true;
    return true;
  return false;
  return false;
}
}
 
 
/* Return true if OP is a tree which we can perform value numbering
/* Return true if OP is a tree which we can perform value numbering
   on.  */
   on.  */
 
 
static bool
static bool
can_value_number_operation (tree op)
can_value_number_operation (tree op)
{
{
  return UNARY_CLASS_P (op)
  return UNARY_CLASS_P (op)
    || BINARY_CLASS_P (op)
    || BINARY_CLASS_P (op)
    || COMPARISON_CLASS_P (op)
    || COMPARISON_CLASS_P (op)
    || REFERENCE_CLASS_P (op)
    || REFERENCE_CLASS_P (op)
    || (TREE_CODE (op) == CALL_EXPR
    || (TREE_CODE (op) == CALL_EXPR
        && can_value_number_call (op));
        && can_value_number_call (op));
}
}
 
 
 
 
/* Return true if OP is a tree which we can perform PRE on
/* Return true if OP is a tree which we can perform PRE on
   on.  This may not match the operations we can value number, but in
   on.  This may not match the operations we can value number, but in
   a perfect world would.  */
   a perfect world would.  */
 
 
static bool
static bool
can_PRE_operation (tree op)
can_PRE_operation (tree op)
{
{
  return UNARY_CLASS_P (op)
  return UNARY_CLASS_P (op)
    || BINARY_CLASS_P (op)
    || BINARY_CLASS_P (op)
    || COMPARISON_CLASS_P (op)
    || COMPARISON_CLASS_P (op)
    || TREE_CODE (op) == INDIRECT_REF
    || TREE_CODE (op) == INDIRECT_REF
    || TREE_CODE (op) == COMPONENT_REF
    || TREE_CODE (op) == COMPONENT_REF
    || TREE_CODE (op) == CALL_EXPR
    || TREE_CODE (op) == CALL_EXPR
    || TREE_CODE (op) == ARRAY_REF;
    || TREE_CODE (op) == ARRAY_REF;
}
}
 
 
 
 
/* Inserted expressions are placed onto this worklist, which is used
/* Inserted expressions are placed onto this worklist, which is used
   for performing quick dead code elimination of insertions we made
   for performing quick dead code elimination of insertions we made
   that didn't turn out to be necessary.   */
   that didn't turn out to be necessary.   */
static VEC(tree,heap) *inserted_exprs;
static VEC(tree,heap) *inserted_exprs;
 
 
/* Pool allocated fake store expressions are placed onto this
/* Pool allocated fake store expressions are placed onto this
   worklist, which, after performing dead code elimination, is walked
   worklist, which, after performing dead code elimination, is walked
   to see which expressions need to be put into GC'able memory  */
   to see which expressions need to be put into GC'able memory  */
static VEC(tree, heap) *need_creation;
static VEC(tree, heap) *need_creation;
 
 
/* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
/* For COMPONENT_REF's and ARRAY_REF's, we can't have any intermediates for the
   COMPONENT_REF or INDIRECT_REF or ARRAY_REF portion, because we'd end up with
   COMPONENT_REF or INDIRECT_REF or ARRAY_REF portion, because we'd end up with
   trying to rename aggregates into ssa form directly, which is a no
   trying to rename aggregates into ssa form directly, which is a no
   no.
   no.
 
 
   Thus, this routine doesn't create temporaries, it just builds a
   Thus, this routine doesn't create temporaries, it just builds a
   single access expression for the array, calling
   single access expression for the array, calling
   find_or_generate_expression to build the innermost pieces.
   find_or_generate_expression to build the innermost pieces.
 
 
   This function is a subroutine of create_expression_by_pieces, and
   This function is a subroutine of create_expression_by_pieces, and
   should not be called on it's own unless you really know what you
   should not be called on it's own unless you really know what you
   are doing.
   are doing.
*/
*/
static tree
static tree
create_component_ref_by_pieces (basic_block block, tree expr, tree stmts)
create_component_ref_by_pieces (basic_block block, tree expr, tree stmts)
{
{
  tree genop = expr;
  tree genop = expr;
  tree folded;
  tree folded;
 
 
  if (TREE_CODE (genop) == VALUE_HANDLE)
  if (TREE_CODE (genop) == VALUE_HANDLE)
    {
    {
      tree found = bitmap_find_leader (AVAIL_OUT (block), expr);
      tree found = bitmap_find_leader (AVAIL_OUT (block), expr);
      if (found)
      if (found)
        return found;
        return found;
    }
    }
 
 
  if (TREE_CODE (genop) == VALUE_HANDLE)
  if (TREE_CODE (genop) == VALUE_HANDLE)
    genop = VALUE_HANDLE_EXPR_SET (expr)->head->expr;
    genop = VALUE_HANDLE_EXPR_SET (expr)->head->expr;
 
 
  switch TREE_CODE (genop)
  switch TREE_CODE (genop)
    {
    {
    case ARRAY_REF:
    case ARRAY_REF:
      {
      {
        tree op0;
        tree op0;
        tree op1, op2, op3;
        tree op1, op2, op3;
        op0 = create_component_ref_by_pieces (block,
        op0 = create_component_ref_by_pieces (block,
                                              TREE_OPERAND (genop, 0),
                                              TREE_OPERAND (genop, 0),
                                              stmts);
                                              stmts);
        op1 = TREE_OPERAND (genop, 1);
        op1 = TREE_OPERAND (genop, 1);
        if (TREE_CODE (op1) == VALUE_HANDLE)
        if (TREE_CODE (op1) == VALUE_HANDLE)
          op1 = find_or_generate_expression (block, op1, stmts);
          op1 = find_or_generate_expression (block, op1, stmts);
        op2 = TREE_OPERAND (genop, 2);
        op2 = TREE_OPERAND (genop, 2);
        if (op2 && TREE_CODE (op2) == VALUE_HANDLE)
        if (op2 && TREE_CODE (op2) == VALUE_HANDLE)
          op2 = find_or_generate_expression (block, op2, stmts);
          op2 = find_or_generate_expression (block, op2, stmts);
        op3 = TREE_OPERAND (genop, 3);
        op3 = TREE_OPERAND (genop, 3);
        if (op3 && TREE_CODE (op3) == VALUE_HANDLE)
        if (op3 && TREE_CODE (op3) == VALUE_HANDLE)
          op3 = find_or_generate_expression (block, op3, stmts);
          op3 = find_or_generate_expression (block, op3, stmts);
        folded = build4 (ARRAY_REF, TREE_TYPE (genop), op0, op1,
        folded = build4 (ARRAY_REF, TREE_TYPE (genop), op0, op1,
                              op2, op3);
                              op2, op3);
        return folded;
        return folded;
      }
      }
    case COMPONENT_REF:
    case COMPONENT_REF:
      {
      {
        tree op0;
        tree op0;
        tree op1;
        tree op1;
        op0 = create_component_ref_by_pieces (block,
        op0 = create_component_ref_by_pieces (block,
                                              TREE_OPERAND (genop, 0),
                                              TREE_OPERAND (genop, 0),
                                              stmts);
                                              stmts);
        op1 = VALUE_HANDLE_EXPR_SET (TREE_OPERAND (genop, 1))->head->expr;
        op1 = VALUE_HANDLE_EXPR_SET (TREE_OPERAND (genop, 1))->head->expr;
        folded = fold_build3 (COMPONENT_REF, TREE_TYPE (genop), op0, op1,
        folded = fold_build3 (COMPONENT_REF, TREE_TYPE (genop), op0, op1,
                              NULL_TREE);
                              NULL_TREE);
        return folded;
        return folded;
      }
      }
      break;
      break;
    case INDIRECT_REF:
    case INDIRECT_REF:
      {
      {
        tree op1 = TREE_OPERAND (genop, 0);
        tree op1 = TREE_OPERAND (genop, 0);
        tree genop1 = find_or_generate_expression (block, op1, stmts);
        tree genop1 = find_or_generate_expression (block, op1, stmts);
 
 
        folded = fold_build1 (TREE_CODE (genop), TREE_TYPE (genop),
        folded = fold_build1 (TREE_CODE (genop), TREE_TYPE (genop),
                              genop1);
                              genop1);
        return folded;
        return folded;
      }
      }
      break;
      break;
    case VAR_DECL:
    case VAR_DECL:
    case PARM_DECL:
    case PARM_DECL:
    case RESULT_DECL:
    case RESULT_DECL:
    case SSA_NAME:
    case SSA_NAME:
    case STRING_CST:
    case STRING_CST:
      return genop;
      return genop;
    default:
    default:
      gcc_unreachable ();
      gcc_unreachable ();
    }
    }
 
 
  return NULL_TREE;
  return NULL_TREE;
}
}
 
 
/* Find a leader for an expression, or generate one using
/* Find a leader for an expression, or generate one using
   create_expression_by_pieces if it's ANTIC but
   create_expression_by_pieces if it's ANTIC but
   complex.
   complex.
   BLOCK is the basic_block we are looking for leaders in.
   BLOCK is the basic_block we are looking for leaders in.
   EXPR is the expression to find a leader or generate for.
   EXPR is the expression to find a leader or generate for.
   STMTS is the statement list to put the inserted expressions on.
   STMTS is the statement list to put the inserted expressions on.
   Returns the SSA_NAME of the LHS of the generated expression or the
   Returns the SSA_NAME of the LHS of the generated expression or the
   leader.  */
   leader.  */
 
 
static tree
static tree
find_or_generate_expression (basic_block block, tree expr, tree stmts)
find_or_generate_expression (basic_block block, tree expr, tree stmts)
{
{
  tree genop = bitmap_find_leader (AVAIL_OUT (block), expr);
  tree genop = bitmap_find_leader (AVAIL_OUT (block), expr);
 
 
  /* If it's still NULL, it must be a complex expression, so generate
  /* If it's still NULL, it must be a complex expression, so generate
     it recursively.  */
     it recursively.  */
  if (genop == NULL)
  if (genop == NULL)
    {
    {
      genop = VALUE_HANDLE_EXPR_SET (expr)->head->expr;
      genop = VALUE_HANDLE_EXPR_SET (expr)->head->expr;
 
 
      gcc_assert (can_PRE_operation (genop));
      gcc_assert (can_PRE_operation (genop));
      genop = create_expression_by_pieces (block, genop, stmts);
      genop = create_expression_by_pieces (block, genop, stmts);
    }
    }
  return genop;
  return genop;
}
}
 
 
#define NECESSARY(stmt)         stmt->common.asm_written_flag
#define NECESSARY(stmt)         stmt->common.asm_written_flag
/* Create an expression in pieces, so that we can handle very complex
/* Create an expression in pieces, so that we can handle very complex
   expressions that may be ANTIC, but not necessary GIMPLE.
   expressions that may be ANTIC, but not necessary GIMPLE.
   BLOCK is the basic block the expression will be inserted into,
   BLOCK is the basic block the expression will be inserted into,
   EXPR is the expression to insert (in value form)
   EXPR is the expression to insert (in value form)
   STMTS is a statement list to append the necessary insertions into.
   STMTS is a statement list to append the necessary insertions into.
 
 
   This function will die if we hit some value that shouldn't be
   This function will die if we hit some value that shouldn't be
   ANTIC but is (IE there is no leader for it, or its components).
   ANTIC but is (IE there is no leader for it, or its components).
   This function may also generate expressions that are themselves
   This function may also generate expressions that are themselves
   partially or fully redundant.  Those that are will be either made
   partially or fully redundant.  Those that are will be either made
   fully redundant during the next iteration of insert (for partially
   fully redundant during the next iteration of insert (for partially
   redundant ones), or eliminated by eliminate (for fully redundant
   redundant ones), or eliminated by eliminate (for fully redundant
   ones).  */
   ones).  */
 
 
static tree
static tree
create_expression_by_pieces (basic_block block, tree expr, tree stmts)
create_expression_by_pieces (basic_block block, tree expr, tree stmts)
{
{
  tree temp, name;
  tree temp, name;
  tree folded, forced_stmts, newexpr;
  tree folded, forced_stmts, newexpr;
  tree v;
  tree v;
  tree_stmt_iterator tsi;
  tree_stmt_iterator tsi;
 
 
  switch (TREE_CODE_CLASS (TREE_CODE (expr)))
  switch (TREE_CODE_CLASS (TREE_CODE (expr)))
    {
    {
    case tcc_expression:
    case tcc_expression:
      {
      {
        tree op0, op2;
        tree op0, op2;
        tree arglist;
        tree arglist;
        tree genop0, genop2;
        tree genop0, genop2;
        tree genarglist;
        tree genarglist;
        tree walker, genwalker;
        tree walker, genwalker;
 
 
        gcc_assert (TREE_CODE (expr) == CALL_EXPR);
        gcc_assert (TREE_CODE (expr) == CALL_EXPR);
        genop2 = NULL;
        genop2 = NULL;
 
 
        op0 = TREE_OPERAND (expr, 0);
        op0 = TREE_OPERAND (expr, 0);
        arglist = TREE_OPERAND (expr, 1);
        arglist = TREE_OPERAND (expr, 1);
        op2 = TREE_OPERAND (expr, 2);
        op2 = TREE_OPERAND (expr, 2);
 
 
        genop0 = find_or_generate_expression (block, op0, stmts);
        genop0 = find_or_generate_expression (block, op0, stmts);
        genarglist = copy_list (arglist);
        genarglist = copy_list (arglist);
        for (walker = arglist, genwalker = genarglist;
        for (walker = arglist, genwalker = genarglist;
             genwalker && walker;
             genwalker && walker;
             genwalker = TREE_CHAIN (genwalker), walker = TREE_CHAIN (walker))
             genwalker = TREE_CHAIN (genwalker), walker = TREE_CHAIN (walker))
          {
          {
            TREE_VALUE (genwalker)
            TREE_VALUE (genwalker)
              = find_or_generate_expression (block, TREE_VALUE (walker),
              = find_or_generate_expression (block, TREE_VALUE (walker),
                                             stmts);
                                             stmts);
          }
          }
 
 
        if (op2)
        if (op2)
          genop2 = find_or_generate_expression (block, op2, stmts);
          genop2 = find_or_generate_expression (block, op2, stmts);
        folded = fold_build3 (TREE_CODE (expr), TREE_TYPE (expr),
        folded = fold_build3 (TREE_CODE (expr), TREE_TYPE (expr),
                              genop0, genarglist, genop2);
                              genop0, genarglist, genop2);
        break;
        break;
 
 
 
 
      }
      }
      break;
      break;
    case tcc_reference:
    case tcc_reference:
      {
      {
        if (TREE_CODE (expr) == COMPONENT_REF
        if (TREE_CODE (expr) == COMPONENT_REF
            || TREE_CODE (expr) == ARRAY_REF)
            || TREE_CODE (expr) == ARRAY_REF)
          {
          {
            folded = create_component_ref_by_pieces (block, expr, stmts);
            folded = create_component_ref_by_pieces (block, expr, stmts);
          }
          }
        else
        else
          {
          {
            tree op1 = TREE_OPERAND (expr, 0);
            tree op1 = TREE_OPERAND (expr, 0);
            tree genop1 = find_or_generate_expression (block, op1, stmts);
            tree genop1 = find_or_generate_expression (block, op1, stmts);
 
 
            folded = fold_build1 (TREE_CODE (expr), TREE_TYPE (expr),
            folded = fold_build1 (TREE_CODE (expr), TREE_TYPE (expr),
                                  genop1);
                                  genop1);
          }
          }
        break;
        break;
      }
      }
 
 
    case tcc_binary:
    case tcc_binary:
    case tcc_comparison:
    case tcc_comparison:
      {
      {
        tree op1 = TREE_OPERAND (expr, 0);
        tree op1 = TREE_OPERAND (expr, 0);
        tree op2 = TREE_OPERAND (expr, 1);
        tree op2 = TREE_OPERAND (expr, 1);
        tree genop1 = find_or_generate_expression (block, op1, stmts);
        tree genop1 = find_or_generate_expression (block, op1, stmts);
        tree genop2 = find_or_generate_expression (block, op2, stmts);
        tree genop2 = find_or_generate_expression (block, op2, stmts);
        folded = fold_build2 (TREE_CODE (expr), TREE_TYPE (expr),
        folded = fold_build2 (TREE_CODE (expr), TREE_TYPE (expr),
                              genop1, genop2);
                              genop1, genop2);
        break;
        break;
      }
      }
 
 
    case tcc_unary:
    case tcc_unary:
      {
      {
        tree op1 = TREE_OPERAND (expr, 0);
        tree op1 = TREE_OPERAND (expr, 0);
        tree genop1 = find_or_generate_expression (block, op1, stmts);
        tree genop1 = find_or_generate_expression (block, op1, stmts);
        folded = fold_build1 (TREE_CODE (expr), TREE_TYPE (expr),
        folded = fold_build1 (TREE_CODE (expr), TREE_TYPE (expr),
                              genop1);
                              genop1);
        break;
        break;
      }
      }
 
 
    default:
    default:
      gcc_unreachable ();
      gcc_unreachable ();
    }
    }
 
 
  /* Force the generated expression to be a sequence of GIMPLE
  /* Force the generated expression to be a sequence of GIMPLE
     statements.
     statements.
     We have to call unshare_expr because force_gimple_operand may
     We have to call unshare_expr because force_gimple_operand may
     modify the tree we pass to it.  */
     modify the tree we pass to it.  */
  newexpr = force_gimple_operand (unshare_expr (folded), &forced_stmts,
  newexpr = force_gimple_operand (unshare_expr (folded), &forced_stmts,
                                  false, NULL);
                                  false, NULL);
 
 
  /* If we have any intermediate expressions to the value sets, add them
  /* If we have any intermediate expressions to the value sets, add them
     to the value sets and chain them on in the instruction stream.  */
     to the value sets and chain them on in the instruction stream.  */
  if (forced_stmts)
  if (forced_stmts)
    {
    {
      tsi = tsi_start (forced_stmts);
      tsi = tsi_start (forced_stmts);
      for (; !tsi_end_p (tsi); tsi_next (&tsi))
      for (; !tsi_end_p (tsi); tsi_next (&tsi))
        {
        {
          tree stmt = tsi_stmt (tsi);
          tree stmt = tsi_stmt (tsi);
          tree forcedname = TREE_OPERAND (stmt, 0);
          tree forcedname = TREE_OPERAND (stmt, 0);
          tree forcedexpr = TREE_OPERAND (stmt, 1);
          tree forcedexpr = TREE_OPERAND (stmt, 1);
          tree val = vn_lookup_or_add (forcedexpr, NULL);
          tree val = vn_lookup_or_add (forcedexpr, NULL);
 
 
          VEC_safe_push (tree, heap, inserted_exprs, stmt);
          VEC_safe_push (tree, heap, inserted_exprs, stmt);
          vn_add (forcedname, val);
          vn_add (forcedname, val);
          bitmap_value_replace_in_set (NEW_SETS (block), forcedname);
          bitmap_value_replace_in_set (NEW_SETS (block), forcedname);
          bitmap_value_replace_in_set (AVAIL_OUT (block), forcedname);
          bitmap_value_replace_in_set (AVAIL_OUT (block), forcedname);
          mark_new_vars_to_rename (stmt);
          mark_new_vars_to_rename (stmt);
        }
        }
      tsi = tsi_last (stmts);
      tsi = tsi_last (stmts);
      tsi_link_after (&tsi, forced_stmts, TSI_CONTINUE_LINKING);
      tsi_link_after (&tsi, forced_stmts, TSI_CONTINUE_LINKING);
    }
    }
 
 
  /* Build and insert the assignment of the end result to the temporary
  /* Build and insert the assignment of the end result to the temporary
     that we will return.  */
     that we will return.  */
  if (!pretemp || TREE_TYPE (expr) != TREE_TYPE (pretemp))
  if (!pretemp || TREE_TYPE (expr) != TREE_TYPE (pretemp))
    {
    {
      pretemp = create_tmp_var (TREE_TYPE (expr), "pretmp");
      pretemp = create_tmp_var (TREE_TYPE (expr), "pretmp");
      get_var_ann (pretemp);
      get_var_ann (pretemp);
    }
    }
 
 
  temp = pretemp;
  temp = pretemp;
  add_referenced_var (temp);
  add_referenced_var (temp);
 
 
  if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
  if (TREE_CODE (TREE_TYPE (expr)) == COMPLEX_TYPE)
    DECL_COMPLEX_GIMPLE_REG_P (temp) = 1;
    DECL_COMPLEX_GIMPLE_REG_P (temp) = 1;
 
 
  newexpr = build2 (MODIFY_EXPR, TREE_TYPE (expr), temp, newexpr);
  newexpr = build2 (MODIFY_EXPR, TREE_TYPE (expr), temp, newexpr);
  name = make_ssa_name (temp, newexpr);
  name = make_ssa_name (temp, newexpr);
  TREE_OPERAND (newexpr, 0) = name;
  TREE_OPERAND (newexpr, 0) = name;
  NECESSARY (newexpr) = 0;
  NECESSARY (newexpr) = 0;
 
 
  tsi = tsi_last (stmts);
  tsi = tsi_last (stmts);
  tsi_link_after (&tsi, newexpr, TSI_CONTINUE_LINKING);
  tsi_link_after (&tsi, newexpr, TSI_CONTINUE_LINKING);
  VEC_safe_push (tree, heap, inserted_exprs, newexpr);
  VEC_safe_push (tree, heap, inserted_exprs, newexpr);
  mark_new_vars_to_rename (newexpr);
  mark_new_vars_to_rename (newexpr);
 
 
  /* Add a value handle to the temporary.
  /* Add a value handle to the temporary.
     The value may already exist in either NEW_SETS, or AVAIL_OUT, because
     The value may already exist in either NEW_SETS, or AVAIL_OUT, because
     we are creating the expression by pieces, and this particular piece of
     we are creating the expression by pieces, and this particular piece of
     the expression may have been represented.  There is no harm in replacing
     the expression may have been represented.  There is no harm in replacing
     here.  */
     here.  */
  v = get_value_handle (expr);
  v = get_value_handle (expr);
  vn_add (name, v);
  vn_add (name, v);
  bitmap_value_replace_in_set (NEW_SETS (block), name);
  bitmap_value_replace_in_set (NEW_SETS (block), name);
  bitmap_value_replace_in_set (AVAIL_OUT (block), name);
  bitmap_value_replace_in_set (AVAIL_OUT (block), name);
 
 
  pre_stats.insertions++;
  pre_stats.insertions++;
  if (dump_file && (dump_flags & TDF_DETAILS))
  if (dump_file && (dump_flags & TDF_DETAILS))
    {
    {
      fprintf (dump_file, "Inserted ");
      fprintf (dump_file, "Inserted ");
      print_generic_expr (dump_file, newexpr, 0);
      print_generic_expr (dump_file, newexpr, 0);
      fprintf (dump_file, " in predecessor %d\n", block->index);
      fprintf (dump_file, " in predecessor %d\n", block->index);
    }
    }
 
 
  return name;
  return name;
}
}
 
 
/* Insert the to-be-made-available values of NODE for each
/* Insert the to-be-made-available values of NODE for each
   predecessor, stored in AVAIL, into the predecessors of BLOCK, and
   predecessor, stored in AVAIL, into the predecessors of BLOCK, and
   merge the result with a phi node, given the same value handle as
   merge the result with a phi node, given the same value handle as
   NODE.  Return true if we have inserted new stuff.  */
   NODE.  Return true if we have inserted new stuff.  */
 
 
static bool
static bool
insert_into_preds_of_block (basic_block block, value_set_node_t node,
insert_into_preds_of_block (basic_block block, value_set_node_t node,
                            tree *avail)
                            tree *avail)
{
{
  tree val = get_value_handle (node->expr);
  tree val = get_value_handle (node->expr);
  edge pred;
  edge pred;
  bool insertions = false;
  bool insertions = false;
  bool nophi = false;
  bool nophi = false;
  basic_block bprime;
  basic_block bprime;
  tree eprime;
  tree eprime;
  edge_iterator ei;
  edge_iterator ei;
  tree type = TREE_TYPE (avail[EDGE_PRED (block, 0)->src->index]);
  tree type = TREE_TYPE (avail[EDGE_PRED (block, 0)->src->index]);
  tree temp;
  tree temp;
 
 
  if (dump_file && (dump_flags & TDF_DETAILS))
  if (dump_file && (dump_flags & TDF_DETAILS))
    {
    {
      fprintf (dump_file, "Found partial redundancy for expression ");
      fprintf (dump_file, "Found partial redundancy for expression ");
      print_generic_expr (dump_file, node->expr, 0);
      print_generic_expr (dump_file, node->expr, 0);
      fprintf (dump_file, " (");
      fprintf (dump_file, " (");
      print_generic_expr (dump_file, val, 0);
      print_generic_expr (dump_file, val, 0);
      fprintf (dump_file, ")");
      fprintf (dump_file, ")");
      fprintf (dump_file, "\n");
      fprintf (dump_file, "\n");
    }
    }
 
 
  /* Make sure we aren't creating an induction variable.  */
  /* Make sure we aren't creating an induction variable.  */
  if (block->loop_depth > 0 && EDGE_COUNT (block->preds) == 2
  if (block->loop_depth > 0 && EDGE_COUNT (block->preds) == 2
      && TREE_CODE_CLASS (TREE_CODE (node->expr)) != tcc_reference )
      && TREE_CODE_CLASS (TREE_CODE (node->expr)) != tcc_reference )
    {
    {
      bool firstinsideloop = false;
      bool firstinsideloop = false;
      bool secondinsideloop = false;
      bool secondinsideloop = false;
      firstinsideloop = flow_bb_inside_loop_p (block->loop_father,
      firstinsideloop = flow_bb_inside_loop_p (block->loop_father,
                                               EDGE_PRED (block, 0)->src);
                                               EDGE_PRED (block, 0)->src);
      secondinsideloop = flow_bb_inside_loop_p (block->loop_father,
      secondinsideloop = flow_bb_inside_loop_p (block->loop_father,
                                                EDGE_PRED (block, 1)->src);
                                                EDGE_PRED (block, 1)->src);
      /* Induction variables only have one edge inside the loop.  */
      /* Induction variables only have one edge inside the loop.  */
      if (firstinsideloop ^ secondinsideloop)
      if (firstinsideloop ^ secondinsideloop)
        {
        {
          if (dump_file && (dump_flags & TDF_DETAILS))
          if (dump_file && (dump_flags & TDF_DETAILS))
            fprintf (dump_file, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
            fprintf (dump_file, "Skipping insertion of phi for partial redundancy: Looks like an induction variable\n");
          nophi = true;
          nophi = true;
        }
        }
    }
    }
 
 
 
 
  /* Make the necessary insertions.  */
  /* Make the necessary insertions.  */
  FOR_EACH_EDGE (pred, ei, block->preds)
  FOR_EACH_EDGE (pred, ei, block->preds)
    {
    {
      tree stmts = alloc_stmt_list ();
      tree stmts = alloc_stmt_list ();
      tree builtexpr;
      tree builtexpr;
      bprime = pred->src;
      bprime = pred->src;
      eprime = avail[bprime->index];
      eprime = avail[bprime->index];
 
 
      if (can_PRE_operation (eprime))
      if (can_PRE_operation (eprime))
        {
        {
#ifdef ENABLE_CHECKING
#ifdef ENABLE_CHECKING
          tree vh;
          tree vh;
 
 
          /* eprime may be an invariant.  */
          /* eprime may be an invariant.  */
          vh = TREE_CODE (eprime) == VALUE_HANDLE
          vh = TREE_CODE (eprime) == VALUE_HANDLE
            ? eprime
            ? eprime
            : get_value_handle (eprime);
            : get_value_handle (eprime);
 
 
          /* ensure that the virtual uses we need reach our block.  */
          /* ensure that the virtual uses we need reach our block.  */
          if (TREE_CODE (vh) == VALUE_HANDLE)
          if (TREE_CODE (vh) == VALUE_HANDLE)
            {
            {
              int i;
              int i;
              tree vuse;
              tree vuse;
              for (i = 0;
              for (i = 0;
                   VEC_iterate (tree, VALUE_HANDLE_VUSES (vh), i, vuse);
                   VEC_iterate (tree, VALUE_HANDLE_VUSES (vh), i, vuse);
                   i++)
                   i++)
                {
                {
                  size_t id = SSA_NAME_VERSION (vuse);
                  size_t id = SSA_NAME_VERSION (vuse);
                  gcc_assert (bitmap_bit_p (RVUSE_OUT (bprime), id)
                  gcc_assert (bitmap_bit_p (RVUSE_OUT (bprime), id)
                              || IS_EMPTY_STMT (SSA_NAME_DEF_STMT (vuse)));
                              || IS_EMPTY_STMT (SSA_NAME_DEF_STMT (vuse)));
                }
                }
            }
            }
#endif
#endif
          builtexpr = create_expression_by_pieces (bprime,
          builtexpr = create_expression_by_pieces (bprime,
                                                   eprime,
                                                   eprime,
                                                   stmts);
                                                   stmts);
          bsi_insert_on_edge (pred, stmts);
          bsi_insert_on_edge (pred, stmts);
          avail[bprime->index] = builtexpr;
          avail[bprime->index] = builtexpr;
          insertions = true;
          insertions = true;
        }
        }
    }
    }
  /* If we didn't want a phi node, and we made insertions, we still have
  /* If we didn't want a phi node, and we made insertions, we still have
     inserted new stuff, and thus return true.  If we didn't want a phi node,
     inserted new stuff, and thus return true.  If we didn't want a phi node,
     and didn't make insertions, we haven't added anything new, so return
     and didn't make insertions, we haven't added anything new, so return
     false.  */
     false.  */
  if (nophi && insertions)
  if (nophi && insertions)
    return true;
    return true;
  else if (nophi && !insertions)
  else if (nophi && !insertions)
    return false;
    return false;
 
 
  /* Now build a phi for the new variable.  */
  /* Now build a phi for the new variable.  */
  if (!prephitemp || TREE_TYPE (prephitemp) != type)
  if (!prephitemp || TREE_TYPE (prephitemp) != type)
    {
    {
      prephitemp = create_tmp_var (type, "prephitmp");
      prephitemp = create_tmp_var (type, "prephitmp");
      get_var_ann (prephitemp);
      get_var_ann (prephitemp);
    }
    }
 
 
  temp = prephitemp;
  temp = prephitemp;
  add_referenced_var (temp);
  add_referenced_var (temp);
 
 
  if (TREE_CODE (type) == COMPLEX_TYPE)
  if (TREE_CODE (type) == COMPLEX_TYPE)
    DECL_COMPLEX_GIMPLE_REG_P (temp) = 1;
    DECL_COMPLEX_GIMPLE_REG_P (temp) = 1;
  temp = create_phi_node (temp, block);
  temp = create_phi_node (temp, block);
 
 
  NECESSARY (temp) = 0;
  NECESSARY (temp) = 0;
  VEC_safe_push (tree, heap, inserted_exprs, temp);
  VEC_safe_push (tree, heap, inserted_exprs, temp);
  FOR_EACH_EDGE (pred, ei, block->preds)
  FOR_EACH_EDGE (pred, ei, block->preds)
    add_phi_arg (temp, avail[pred->src->index], pred);
    add_phi_arg (temp, avail[pred->src->index], pred);
 
 
  vn_add (PHI_RESULT (temp), val);
  vn_add (PHI_RESULT (temp), val);
 
 
  /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
  /* The value should *not* exist in PHI_GEN, or else we wouldn't be doing
     this insertion, since we test for the existence of this value in PHI_GEN
     this insertion, since we test for the existence of this value in PHI_GEN
     before proceeding with the partial redundancy checks in insert_aux.
     before proceeding with the partial redundancy checks in insert_aux.
 
 
     The value may exist in AVAIL_OUT, in particular, it could be represented
     The value may exist in AVAIL_OUT, in particular, it could be represented
     by the expression we are trying to eliminate, in which case we want the
     by the expression we are trying to eliminate, in which case we want the
     replacement to occur.  If it's not existing in AVAIL_OUT, we want it
     replacement to occur.  If it's not existing in AVAIL_OUT, we want it
     inserted there.
     inserted there.
 
 
     Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
     Similarly, to the PHI_GEN case, the value should not exist in NEW_SETS of
     this block, because if it did, it would have existed in our dominator's
     this block, because if it did, it would have existed in our dominator's
     AVAIL_OUT, and would have been skipped due to the full redundancy check.
     AVAIL_OUT, and would have been skipped due to the full redundancy check.
  */
  */
 
 
  bitmap_insert_into_set (PHI_GEN (block),
  bitmap_insert_into_set (PHI_GEN (block),
                          PHI_RESULT (temp));
                          PHI_RESULT (temp));
  bitmap_value_replace_in_set (AVAIL_OUT (block),
  bitmap_value_replace_in_set (AVAIL_OUT (block),
                               PHI_RESULT (temp));
                               PHI_RESULT (temp));
  bitmap_insert_into_set (NEW_SETS (block),
  bitmap_insert_into_set (NEW_SETS (block),
                          PHI_RESULT (temp));
                          PHI_RESULT (temp));
 
 
  if (dump_file && (dump_flags & TDF_DETAILS))
  if (dump_file && (dump_flags & TDF_DETAILS))
    {
    {
      fprintf (dump_file, "Created phi ");
      fprintf (dump_file, "Created phi ");
      print_generic_expr (dump_file, temp, 0);
      print_generic_expr (dump_file, temp, 0);
      fprintf (dump_file, " in block %d\n", block->index);
      fprintf (dump_file, " in block %d\n", block->index);
    }
    }
  pre_stats.phis++;
  pre_stats.phis++;
  return true;
  return true;
}
}
 
 
 
 
 
 
/* Perform insertion of partially redundant values.
/* Perform insertion of partially redundant values.
   For BLOCK, do the following:
   For BLOCK, do the following:
   1.  Propagate the NEW_SETS of the dominator into the current block.
   1.  Propagate the NEW_SETS of the dominator into the current block.
   If the block has multiple predecessors,
   If the block has multiple predecessors,
       2a. Iterate over the ANTIC expressions for the block to see if
       2a. Iterate over the ANTIC expressions for the block to see if
           any of them are partially redundant.
           any of them are partially redundant.
       2b. If so, insert them into the necessary predecessors to make
       2b. If so, insert them into the necessary predecessors to make
           the expression fully redundant.
           the expression fully redundant.
       2c. Insert a new PHI merging the values of the predecessors.
       2c. Insert a new PHI merging the values of the predecessors.
       2d. Insert the new PHI, and the new expressions, into the
       2d. Insert the new PHI, and the new expressions, into the
           NEW_SETS set.
           NEW_SETS set.
   3. Recursively call ourselves on the dominator children of BLOCK.
   3. Recursively call ourselves on the dominator children of BLOCK.
 
 
*/
*/
 
 
static bool
static bool
insert_aux (basic_block block)
insert_aux (basic_block block)
{
{
  basic_block son;
  basic_block son;
  bool new_stuff = false;
  bool new_stuff = false;
 
 
  if (block)
  if (block)
    {
    {
      basic_block dom;
      basic_block dom;
      dom = get_immediate_dominator (CDI_DOMINATORS, block);
      dom = get_immediate_dominator (CDI_DOMINATORS, block);
      if (dom)
      if (dom)
        {
        {
          unsigned i;
          unsigned i;
          bitmap_iterator bi;
          bitmap_iterator bi;
          bitmap_set_t newset = NEW_SETS (dom);
          bitmap_set_t newset = NEW_SETS (dom);
          if (newset)
          if (newset)
            {
            {
              /* Note that we need to value_replace both NEW_SETS, and
              /* Note that we need to value_replace both NEW_SETS, and
                 AVAIL_OUT. For both the case of NEW_SETS, the value may be
                 AVAIL_OUT. For both the case of NEW_SETS, the value may be
                 represented by some non-simple expression here that we want
                 represented by some non-simple expression here that we want
                 to replace it with.  */
                 to replace it with.  */
              EXECUTE_IF_SET_IN_BITMAP (newset->expressions, 0, i, bi)
              EXECUTE_IF_SET_IN_BITMAP (newset->expressions, 0, i, bi)
                {
                {
                  bitmap_value_replace_in_set (NEW_SETS (block), ssa_name (i));
                  bitmap_value_replace_in_set (NEW_SETS (block), ssa_name (i));
                  bitmap_value_replace_in_set (AVAIL_OUT (block), ssa_name (i));
                  bitmap_value_replace_in_set (AVAIL_OUT (block), ssa_name (i));
                }
                }
            }
            }
          if (!single_pred_p (block))
          if (!single_pred_p (block))
            {
            {
              value_set_node_t node;
              value_set_node_t node;
              for (node = ANTIC_IN (block)->head;
              for (node = ANTIC_IN (block)->head;
                   node;
                   node;
                   node = node->next)
                   node = node->next)
                {
                {
                  if (can_PRE_operation (node->expr)
                  if (can_PRE_operation (node->expr)
                      && !AGGREGATE_TYPE_P (TREE_TYPE (node->expr)))
                      && !AGGREGATE_TYPE_P (TREE_TYPE (node->expr)))
                    {
                    {
                      tree *avail;
                      tree *avail;
                      tree val;
                      tree val;
                      bool by_some = false;
                      bool by_some = false;
                      bool cant_insert = false;
                      bool cant_insert = false;
                      bool all_same = true;
                      bool all_same = true;
                      tree first_s = NULL;
                      tree first_s = NULL;
                      edge pred;
                      edge pred;
                      basic_block bprime;
                      basic_block bprime;
                      tree eprime = NULL_TREE;
                      tree eprime = NULL_TREE;
                      edge_iterator ei;
                      edge_iterator ei;
 
 
                      val = get_value_handle (node->expr);
                      val = get_value_handle (node->expr);
                      if (bitmap_set_contains_value (PHI_GEN (block), val))
                      if (bitmap_set_contains_value (PHI_GEN (block), val))
                        continue;
                        continue;
                      if (bitmap_set_contains_value (AVAIL_OUT (dom), val))
                      if (bitmap_set_contains_value (AVAIL_OUT (dom), val))
                        {
                        {
                          if (dump_file && (dump_flags & TDF_DETAILS))
                          if (dump_file && (dump_flags & TDF_DETAILS))
                            fprintf (dump_file, "Found fully redundant value\n");
                            fprintf (dump_file, "Found fully redundant value\n");
                          continue;
                          continue;
                        }
                        }
 
 
                      avail = XCNEWVEC (tree, last_basic_block);
                      avail = XCNEWVEC (tree, last_basic_block);
                      FOR_EACH_EDGE (pred, ei, block->preds)
                      FOR_EACH_EDGE (pred, ei, block->preds)
                        {
                        {
                          tree vprime;
                          tree vprime;
                          tree edoubleprime;
                          tree edoubleprime;
 
 
                          /* This can happen in the very weird case
                          /* This can happen in the very weird case
                             that our fake infinite loop edges have caused a
                             that our fake infinite loop edges have caused a
                             critical edge to appear.  */
                             critical edge to appear.  */
                          if (EDGE_CRITICAL_P (pred))
                          if (EDGE_CRITICAL_P (pred))
                            {
                            {
                              cant_insert = true;
                              cant_insert = true;
                              break;
                              break;
                            }
                            }
                          bprime = pred->src;
                          bprime = pred->src;
                          eprime = phi_translate (node->expr,
                          eprime = phi_translate (node->expr,
                                                  ANTIC_IN (block),
                                                  ANTIC_IN (block),
                                                  bprime, block);
                                                  bprime, block);
 
 
                          /* eprime will generally only be NULL if the
                          /* eprime will generally only be NULL if the
                             value of the expression, translated
                             value of the expression, translated
                             through the PHI for this predecessor, is
                             through the PHI for this predecessor, is
                             undefined.  If that is the case, we can't
                             undefined.  If that is the case, we can't
                             make the expression fully redundant,
                             make the expression fully redundant,
                             because its value is undefined along a
                             because its value is undefined along a
                             predecessor path.  We can thus break out
                             predecessor path.  We can thus break out
                             early because it doesn't matter what the
                             early because it doesn't matter what the
                             rest of the results are.  */
                             rest of the results are.  */
                          if (eprime == NULL)
                          if (eprime == NULL)
                            {
                            {
                              cant_insert = true;
                              cant_insert = true;
                              break;
                              break;
                            }
                            }
 
 
                          eprime = fully_constant_expression (eprime);
                          eprime = fully_constant_expression (eprime);
                          vprime = get_value_handle (eprime);
                          vprime = get_value_handle (eprime);
                          gcc_assert (vprime);
                          gcc_assert (vprime);
                          edoubleprime = bitmap_find_leader (AVAIL_OUT (bprime),
                          edoubleprime = bitmap_find_leader (AVAIL_OUT (bprime),
                                                             vprime);
                                                             vprime);
                          if (edoubleprime == NULL)
                          if (edoubleprime == NULL)
                            {
                            {
                              avail[bprime->index] = eprime;
                              avail[bprime->index] = eprime;
                              all_same = false;
                              all_same = false;
                            }
                            }
                          else
                          else
                            {
                            {
                              avail[bprime->index] = edoubleprime;
                              avail[bprime->index] = edoubleprime;
                              by_some = true;
                              by_some = true;
                              if (first_s == NULL)
                              if (first_s == NULL)
                                first_s = edoubleprime;
                                first_s = edoubleprime;
                              else if (!operand_equal_p (first_s, edoubleprime,
                              else if (!operand_equal_p (first_s, edoubleprime,
                                                         0))
                                                         0))
                                all_same = false;
                                all_same = false;
                            }
                            }
                        }
                        }
                      /* If we can insert it, it's not the same value
                      /* If we can insert it, it's not the same value
                         already existing along every predecessor, and
                         already existing along every predecessor, and
                         it's defined by some predecessor, it is
                         it's defined by some predecessor, it is
                         partially redundant.  */
                         partially redundant.  */
                      if (!cant_insert && !all_same && by_some)
                      if (!cant_insert && !all_same && by_some)
                        {
                        {
                          if (insert_into_preds_of_block (block, node, avail))
                          if (insert_into_preds_of_block (block, node, avail))
                            new_stuff = true;
                            new_stuff = true;
                        }
                        }
                      /* If all edges produce the same value and that value is
                      /* If all edges produce the same value and that value is
                         an invariant, then the PHI has the same value on all
                         an invariant, then the PHI has the same value on all
                         edges.  Note this.  */
                         edges.  Note this.  */
                      else if (!cant_insert && all_same && eprime
                      else if (!cant_insert && all_same && eprime
                               && is_gimple_min_invariant (eprime)
                               && is_gimple_min_invariant (eprime)
                               && !is_gimple_min_invariant (val))
                               && !is_gimple_min_invariant (val))
                        {
                        {
                          value_set_t exprset = VALUE_HANDLE_EXPR_SET (val);
                          value_set_t exprset = VALUE_HANDLE_EXPR_SET (val);
                          value_set_node_t node;
                          value_set_node_t node;
 
 
                          for (node = exprset->head; node; node = node->next)
                          for (node = exprset->head; node; node = node->next)
                            {
                            {
                              if (TREE_CODE (node->expr) == SSA_NAME)
                              if (TREE_CODE (node->expr) == SSA_NAME)
                                {
                                {
                                  vn_add (node->expr, eprime);
                                  vn_add (node->expr, eprime);
                                  pre_stats.constified++;
                                  pre_stats.constified++;
                                }
                                }
                            }
                            }
                        }
                        }
                      free (avail);
                      free (avail);
                    }
                    }
                }
                }
            }
            }
        }
        }
    }
    }
  for (son = first_dom_son (CDI_DOMINATORS, block);
  for (son = first_dom_son (CDI_DOMINATORS, block);
       son;
       son;
       son = next_dom_son (CDI_DOMINATORS, son))
       son = next_dom_son (CDI_DOMINATORS, son))
    {
    {
      new_stuff |= insert_aux (son);
      new_stuff |= insert_aux (son);
    }
    }
 
 
  return new_stuff;
  return new_stuff;
}
}
 
 
/* Perform insertion of partially redundant values.  */
/* Perform insertion of partially redundant values.  */
 
 
static void
static void
insert (void)
insert (void)
{
{
  bool new_stuff = true;
  bool new_stuff = true;
  basic_block bb;
  basic_block bb;
  int num_iterations = 0;
  int num_iterations = 0;
 
 
  FOR_ALL_BB (bb)
  FOR_ALL_BB (bb)
    NEW_SETS (bb) = bitmap_set_new ();
    NEW_SETS (bb) = bitmap_set_new ();
 
 
  while (new_stuff)
  while (new_stuff)
    {
    {
      num_iterations++;
      num_iterations++;
      new_stuff = false;
      new_stuff = false;
      new_stuff = insert_aux (ENTRY_BLOCK_PTR);
      new_stuff = insert_aux (ENTRY_BLOCK_PTR);
    }
    }
  if (num_iterations > 2 && dump_file && (dump_flags & TDF_STATS))
  if (num_iterations > 2 && dump_file && (dump_flags & TDF_STATS))
    fprintf (dump_file, "insert required %d iterations\n", num_iterations);
    fprintf (dump_file, "insert required %d iterations\n", num_iterations);
}
}
 
 
 
 
/* Return true if VAR is an SSA variable with no defining statement in
/* Return true if VAR is an SSA variable with no defining statement in
   this procedure, *AND* isn't a live-on-entry parameter.  */
   this procedure, *AND* isn't a live-on-entry parameter.  */
 
 
static bool
static bool
is_undefined_value (tree expr)
is_undefined_value (tree expr)
{
{
  return (TREE_CODE (expr) == SSA_NAME
  return (TREE_CODE (expr) == SSA_NAME
          && IS_EMPTY_STMT (SSA_NAME_DEF_STMT (expr))
          && IS_EMPTY_STMT (SSA_NAME_DEF_STMT (expr))
          /* PARM_DECLs and hard registers are always defined.  */
          /* PARM_DECLs and hard registers are always defined.  */
          && TREE_CODE (SSA_NAME_VAR (expr)) != PARM_DECL);
          && TREE_CODE (SSA_NAME_VAR (expr)) != PARM_DECL);
}
}
 
 
 
 
/* Given an SSA variable VAR and an expression EXPR, compute the value
/* Given an SSA variable VAR and an expression EXPR, compute the value
   number for EXPR and create a value handle (VAL) for it.  If VAR and
   number for EXPR and create a value handle (VAL) for it.  If VAR and
   EXPR are not the same, associate VAL with VAR.  Finally, add VAR to
   EXPR are not the same, associate VAL with VAR.  Finally, add VAR to
   S1 and its value handle to S2.
   S1 and its value handle to S2.
 
 
   VUSES represent the virtual use operands associated with EXPR (if
   VUSES represent the virtual use operands associated with EXPR (if
   any).  */
   any).  */
 
 
static inline void
static inline void
add_to_sets (tree var, tree expr, tree stmt, bitmap_set_t s1,
add_to_sets (tree var, tree expr, tree stmt, bitmap_set_t s1,
             bitmap_set_t s2)
             bitmap_set_t s2)
{
{
  tree val = vn_lookup_or_add (expr, stmt);
  tree val = vn_lookup_or_add (expr, stmt);
 
 
  /* VAR and EXPR may be the same when processing statements for which
  /* VAR and EXPR may be the same when processing statements for which
     we are not computing value numbers (e.g., non-assignments, or
     we are not computing value numbers (e.g., non-assignments, or
     statements that make aliased stores).  In those cases, we are
     statements that make aliased stores).  In those cases, we are
     only interested in making VAR available as its own value.  */
     only interested in making VAR available as its own value.  */
  if (var != expr)
  if (var != expr)
    vn_add (var, val);
    vn_add (var, val);
 
 
  if (s1)
  if (s1)
    bitmap_insert_into_set (s1, var);
    bitmap_insert_into_set (s1, var);
  bitmap_value_insert_into_set (s2, var);
  bitmap_value_insert_into_set (s2, var);
}
}
 
 
 
 
/* Given a unary or binary expression EXPR, create and return a new
/* Given a unary or binary expression EXPR, create and return a new
   expression with the same structure as EXPR but with its operands
   expression with the same structure as EXPR but with its operands
   replaced with the value handles of each of the operands of EXPR.
   replaced with the value handles of each of the operands of EXPR.
 
 
   VUSES represent the virtual use operands associated with EXPR (if
   VUSES represent the virtual use operands associated with EXPR (if
   any). Insert EXPR's operands into the EXP_GEN set for BLOCK. */
   any). Insert EXPR's operands into the EXP_GEN set for BLOCK. */
 
 
static inline tree
static inline tree
create_value_expr_from (tree expr, basic_block block, tree stmt)
create_value_expr_from (tree expr, basic_block block, tree stmt)
{
{
  int i;
  int i;
  enum tree_code code = TREE_CODE (expr);
  enum tree_code code = TREE_CODE (expr);
  tree vexpr;
  tree vexpr;
  alloc_pool pool;
  alloc_pool pool;
 
 
  gcc_assert (TREE_CODE_CLASS (code) == tcc_unary
  gcc_assert (TREE_CODE_CLASS (code) == tcc_unary
              || TREE_CODE_CLASS (code) == tcc_binary
              || TREE_CODE_CLASS (code) == tcc_binary
              || TREE_CODE_CLASS (code) == tcc_comparison
              || TREE_CODE_CLASS (code) == tcc_comparison
              || TREE_CODE_CLASS (code) == tcc_reference
              || TREE_CODE_CLASS (code) == tcc_reference
              || TREE_CODE_CLASS (code) == tcc_expression
              || TREE_CODE_CLASS (code) == tcc_expression
              || TREE_CODE_CLASS (code) == tcc_exceptional
              || TREE_CODE_CLASS (code) == tcc_exceptional
              || TREE_CODE_CLASS (code) == tcc_declaration);
              || TREE_CODE_CLASS (code) == tcc_declaration);
 
 
  if (TREE_CODE_CLASS (code) == tcc_unary)
  if (TREE_CODE_CLASS (code) == tcc_unary)
    pool = unary_node_pool;
    pool = unary_node_pool;
  else if (TREE_CODE_CLASS (code) == tcc_reference)
  else if (TREE_CODE_CLASS (code) == tcc_reference)
    pool = reference_node_pool;
    pool = reference_node_pool;
  else if (TREE_CODE_CLASS (code) == tcc_binary)
  else if (TREE_CODE_CLASS (code) == tcc_binary)
    pool = binary_node_pool;
    pool = binary_node_pool;
  else if (TREE_CODE_CLASS (code) == tcc_comparison)
  else if (TREE_CODE_CLASS (code) == tcc_comparison)
    pool = comparison_node_pool;
    pool = comparison_node_pool;
  else if (TREE_CODE_CLASS (code) == tcc_exceptional)
  else if (TREE_CODE_CLASS (code) == tcc_exceptional)
    {
    {
      gcc_assert (code == TREE_LIST);
      gcc_assert (code == TREE_LIST);
      pool = list_node_pool;
      pool = list_node_pool;
    }
    }
  else
  else
    {
    {
      gcc_assert (code == CALL_EXPR);
      gcc_assert (code == CALL_EXPR);
      pool = expression_node_pool;
      pool = expression_node_pool;
    }
    }
 
 
  vexpr = (tree) pool_alloc (pool);
  vexpr = (tree) pool_alloc (pool);
  memcpy (vexpr, expr, tree_size (expr));
  memcpy (vexpr, expr, tree_size (expr));
 
 
  /* This case is only for TREE_LIST's that appear as part of
  /* This case is only for TREE_LIST's that appear as part of
     CALL_EXPR's.  Anything else is a bug, but we can't easily verify
     CALL_EXPR's.  Anything else is a bug, but we can't easily verify
     this, hence this comment.  TREE_LIST is not handled by the
     this, hence this comment.  TREE_LIST is not handled by the
     general case below is because they don't have a fixed length, or
     general case below is because they don't have a fixed length, or
     operands, so you can't access purpose/value/chain through
     operands, so you can't access purpose/value/chain through
     TREE_OPERAND macros.  */
     TREE_OPERAND macros.  */
 
 
  if (code == TREE_LIST)
  if (code == TREE_LIST)
    {
    {
      tree op = NULL_TREE;
      tree op = NULL_TREE;
      tree temp = NULL_TREE;
      tree temp = NULL_TREE;
      if (TREE_CHAIN (vexpr))
      if (TREE_CHAIN (vexpr))
        temp = create_value_expr_from (TREE_CHAIN (vexpr), block, stmt);
        temp = create_value_expr_from (TREE_CHAIN (vexpr), block, stmt);
      TREE_CHAIN (vexpr) = temp ? temp : TREE_CHAIN (vexpr);
      TREE_CHAIN (vexpr) = temp ? temp : TREE_CHAIN (vexpr);
 
 
 
 
      /* Recursively value-numberize reference ops.  */
      /* Recursively value-numberize reference ops.  */
      if (REFERENCE_CLASS_P (TREE_VALUE (vexpr)))
      if (REFERENCE_CLASS_P (TREE_VALUE (vexpr)))
        {
        {
          tree tempop;
          tree tempop;
          op = TREE_VALUE (vexpr);
          op = TREE_VALUE (vexpr);
          tempop = create_value_expr_from (op, block, stmt);
          tempop = create_value_expr_from (op, block, stmt);
          op = tempop ? tempop : op;
          op = tempop ? tempop : op;
 
 
          TREE_VALUE (vexpr)  = vn_lookup_or_add (op, stmt);
          TREE_VALUE (vexpr)  = vn_lookup_or_add (op, stmt);
        }
        }
      else
      else
        {
        {
          op = TREE_VALUE (vexpr);
          op = TREE_VALUE (vexpr);
          TREE_VALUE (vexpr) = vn_lookup_or_add (TREE_VALUE (vexpr), NULL);
          TREE_VALUE (vexpr) = vn_lookup_or_add (TREE_VALUE (vexpr), NULL);
        }
        }
      /* This is the equivalent of inserting op into EXP_GEN like we
      /* This is the equivalent of inserting op into EXP_GEN like we
         do below */
         do below */
      if (!is_undefined_value (op))
      if (!is_undefined_value (op))
        value_insert_into_set (EXP_GEN (block), op);
        value_insert_into_set (EXP_GEN (block), op);
 
 
      return vexpr;
      return vexpr;
    }
    }
 
 
  for (i = 0; i < TREE_CODE_LENGTH (code); i++)
  for (i = 0; i < TREE_CODE_LENGTH (code); i++)
    {
    {
      tree val, op;
      tree val, op;
 
 
      op = TREE_OPERAND (expr, i);
      op = TREE_OPERAND (expr, i);
      if (op == NULL_TREE)
      if (op == NULL_TREE)
        continue;
        continue;
 
 
      /* Recursively value-numberize reference ops and tree lists.  */
      /* Recursively value-numberize reference ops and tree lists.  */
      if (REFERENCE_CLASS_P (op))
      if (REFERENCE_CLASS_P (op))
        {
        {
          tree tempop = create_value_expr_from (op, block, stmt);
          tree tempop = create_value_expr_from (op, block, stmt);
          op = tempop ? tempop : op;
          op = tempop ? tempop : op;
          val = vn_lookup_or_add (op, stmt);
          val = vn_lookup_or_add (op, stmt);
        }
        }
      else if (TREE_CODE (op) == TREE_LIST)
      else if (TREE_CODE (op) == TREE_LIST)
        {
        {
          tree tempop;
          tree tempop;
 
 
          gcc_assert (TREE_CODE (expr) == CALL_EXPR);
          gcc_assert (TREE_CODE (expr) == CALL_EXPR);
          tempop = create_value_expr_from (op, block, stmt);
          tempop = create_value_expr_from (op, block, stmt);
 
 
          op = tempop ? tempop : op;
          op = tempop ? tempop : op;
          vn_lookup_or_add (op, NULL);
          vn_lookup_or_add (op, NULL);
          /* Unlike everywhere else, we do *not* want to replace the
          /* Unlike everywhere else, we do *not* want to replace the
             TREE_LIST itself with a value number, because support
             TREE_LIST itself with a value number, because support
             functions we call will blow up.  */
             functions we call will blow up.  */
          val = op;
          val = op;
        }
        }
      else
      else
        /* Create a value handle for OP and add it to VEXPR.  */
        /* Create a value handle for OP and add it to VEXPR.  */
        val = vn_lookup_or_add (op, NULL);
        val = vn_lookup_or_add (op, NULL);
 
 
      if (!is_undefined_value (op) && TREE_CODE (op) != TREE_LIST)
      if (!is_undefined_value (op) && TREE_CODE (op) != TREE_LIST)
        value_insert_into_set (EXP_GEN (block), op);
        value_insert_into_set (EXP_GEN (block), op);
 
 
      if (TREE_CODE (val) == VALUE_HANDLE)
      if (TREE_CODE (val) == VALUE_HANDLE)
        TREE_TYPE (val) = TREE_TYPE (TREE_OPERAND (vexpr, i));
        TREE_TYPE (val) = TREE_TYPE (TREE_OPERAND (vexpr, i));
 
 
      TREE_OPERAND (vexpr, i) = val;
      TREE_OPERAND (vexpr, i) = val;
    }
    }
 
 
  return vexpr;
  return vexpr;
}
}
 
 
 
 
 
 
/* Insert extra phis to merge values that are fully available from
/* Insert extra phis to merge values that are fully available from
   preds of BLOCK, but have no dominating representative coming from
   preds of BLOCK, but have no dominating representative coming from
   block DOM.   */
   block DOM.   */
 
 
static void
static void
insert_extra_phis (basic_block block, basic_block dom)
insert_extra_phis (basic_block block, basic_block dom)
{
{
 
 
  if (!single_pred_p (block))
  if (!single_pred_p (block))
    {
    {
      edge e;
      edge e;
      edge_iterator ei;
      edge_iterator ei;
      bool first = true;
      bool first = true;
      bitmap_set_t tempset = bitmap_set_new ();
      bitmap_set_t tempset = bitmap_set_new ();
 
 
      FOR_EACH_EDGE (e, ei, block->preds)
      FOR_EACH_EDGE (e, ei, block->preds)
        {
        {
          /* We cannot handle abnormal incoming edges correctly.  */
          /* We cannot handle abnormal incoming edges correctly.  */
          if (e->flags & EDGE_ABNORMAL)
          if (e->flags & EDGE_ABNORMAL)
            return;
            return;
 
 
          if (first)
          if (first)
            {
            {
              bitmap_set_copy (tempset, AVAIL_OUT (e->src));
              bitmap_set_copy (tempset, AVAIL_OUT (e->src));
              first = false;
              first = false;
            }
            }
          else
          else
            bitmap_set_and (tempset, AVAIL_OUT (e->src));
            bitmap_set_and (tempset, AVAIL_OUT (e->src));
        }
        }
 
 
      if (dom)
      if (dom)
        bitmap_set_and_compl (tempset, AVAIL_OUT (dom));
        bitmap_set_and_compl (tempset, AVAIL_OUT (dom));
 
 
      if (!bitmap_set_empty_p (tempset))
      if (!bitmap_set_empty_p (tempset))
        {
        {
          unsigned int i;
          unsigned int i;
          bitmap_iterator bi;
          bitmap_iterator bi;
 
 
          EXECUTE_IF_SET_IN_BITMAP (tempset->expressions, 0, i, bi)
          EXECUTE_IF_SET_IN_BITMAP (tempset->expressions, 0, i, bi)
            {
            {
              tree name = ssa_name (i);
              tree name = ssa_name (i);
              tree val = get_value_handle (name);
              tree val = get_value_handle (name);
              tree temp;
              tree temp;
 
 
              if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
              if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name))
                continue;
                continue;
 
 
              if (!mergephitemp
              if (!mergephitemp
                  || TREE_TYPE (name) != TREE_TYPE (mergephitemp))
                  || TREE_TYPE (name) != TREE_TYPE (mergephitemp))
                {
                {
                  mergephitemp = create_tmp_var (TREE_TYPE (name),
                  mergephitemp = create_tmp_var (TREE_TYPE (name),
                                                 "mergephitmp");
                                                 "mergephitmp");
                  get_var_ann (mergephitemp);
                  get_var_ann (mergephitemp);
                }
                }
              temp = mergephitemp;
              temp = mergephitemp;
 
 
              if (dump_file && (dump_flags & TDF_DETAILS))
              if (dump_file && (dump_flags & TDF_DETAILS))
                {
                {
                  fprintf (dump_file, "Creating phi ");
                  fprintf (dump_file, "Creating phi ");
                  print_generic_expr (dump_file, temp, 0);
                  print_generic_expr (dump_file, temp, 0);
                  fprintf (dump_file, " to merge available but not dominating values ");
                  fprintf (dump_file, " to merge available but not dominating values ");
                }
                }
 
 
              add_referenced_var (temp);
              add_referenced_var (temp);
              temp = create_phi_node (temp, block);
              temp = create_phi_node (temp, block);
              NECESSARY (temp) = 0;
              NECESSARY (temp) = 0;
              VEC_safe_push (tree, heap, inserted_exprs, temp);
              VEC_safe_push (tree, heap, inserted_exprs, temp);
 
 
              FOR_EACH_EDGE (e, ei, block->preds)
              FOR_EACH_EDGE (e, ei, block->preds)
                {
                {
                  tree leader = bitmap_find_leader (AVAIL_OUT (e->src), val);
                  tree leader = bitmap_find_leader (AVAIL_OUT (e->src), val);
 
 
                  gcc_assert (leader);
                  gcc_assert (leader);
                  add_phi_arg (temp, leader, e);
                  add_phi_arg (temp, leader, e);
 
 
                  if (dump_file && (dump_flags & TDF_DETAILS))
                  if (dump_file && (dump_flags & TDF_DETAILS))
                    {
                    {
                      print_generic_expr (dump_file, leader, 0);
                      print_generic_expr (dump_file, leader, 0);
                      fprintf (dump_file, " in block %d,", e->src->index);
                      fprintf (dump_file, " in block %d,", e->src->index);
                    }
                    }
                }
                }
 
 
              vn_add (PHI_RESULT (temp), val);
              vn_add (PHI_RESULT (temp), val);
 
 
              if (dump_file && (dump_flags & TDF_DETAILS))
              if (dump_file && (dump_flags & TDF_DETAILS))
                fprintf (dump_file, "\n");
                fprintf (dump_file, "\n");
            }
            }
        }
        }
    }
    }
}
}
 
 
/* Given a statement STMT and its right hand side which is a load, try
/* Given a statement STMT and its right hand side which is a load, try
   to look for the expression stored in the location for the load, and
   to look for the expression stored in the location for the load, and
   return true if a useful equivalence was recorded for LHS.  */
   return true if a useful equivalence was recorded for LHS.  */
 
 
static bool
static bool
try_look_through_load (tree lhs, tree mem_ref, tree stmt, basic_block block)
try_look_through_load (tree lhs, tree mem_ref, tree stmt, basic_block block)
{
{
  tree store_stmt = NULL;
  tree store_stmt = NULL;
  tree rhs;
  tree rhs;
  ssa_op_iter i;
  ssa_op_iter i;
  tree vuse;
  tree vuse;
 
 
  FOR_EACH_SSA_TREE_OPERAND (vuse, stmt, i, SSA_OP_VIRTUAL_USES)
  FOR_EACH_SSA_TREE_OPERAND (vuse, stmt, i, SSA_OP_VIRTUAL_USES)
    {
    {
      tree def_stmt;
      tree def_stmt;
 
 
      gcc_assert (TREE_CODE (vuse) == SSA_NAME);
      gcc_assert (TREE_CODE (vuse) == SSA_NAME);
      def_stmt = SSA_NAME_DEF_STMT (vuse);
      def_stmt = SSA_NAME_DEF_STMT (vuse);
 
 
      /* If there is no useful statement for this VUSE, we'll not find a
      /* If there is no useful statement for this VUSE, we'll not find a
         useful expression to return either.  Likewise, if there is a
         useful expression to return either.  Likewise, if there is a
         statement but it is not a simple assignment or it has virtual
         statement but it is not a simple assignment or it has virtual
         uses, we can stop right here.  Note that this means we do
         uses, we can stop right here.  Note that this means we do
         not look through PHI nodes, which is intentional.  */
         not look through PHI nodes, which is intentional.  */
      if (!def_stmt
      if (!def_stmt
          || TREE_CODE (def_stmt) != MODIFY_EXPR
          || TREE_CODE (def_stmt) != MODIFY_EXPR
          || !ZERO_SSA_OPERANDS (def_stmt, SSA_OP_VIRTUAL_USES))
          || !ZERO_SSA_OPERANDS (def_stmt, SSA_OP_VIRTUAL_USES))
        return false;
        return false;
 
 
      /* If this is not the same statement as one we have looked at for
      /* If this is not the same statement as one we have looked at for
         another VUSE of STMT already, we have two statements producing
         another VUSE of STMT already, we have two statements producing
         something that reaches our STMT.  */
         something that reaches our STMT.  */
      if (store_stmt && store_stmt != def_stmt)
      if (store_stmt && store_stmt != def_stmt)
        return false;
        return false;
      else
      else
        {
        {
          /* Is this a store to the exact same location as the one we are
          /* Is this a store to the exact same location as the one we are
             loading from in STMT?  */
             loading from in STMT?  */
          if (!operand_equal_p (TREE_OPERAND (def_stmt, 0), mem_ref, 0))
          if (!operand_equal_p (TREE_OPERAND (def_stmt, 0), mem_ref, 0))
            return false;
            return false;
 
 
          /* Otherwise remember this statement and see if all other VUSEs
          /* Otherwise remember this statement and see if all other VUSEs
             come from the same statement.  */
             come from the same statement.  */
          store_stmt = def_stmt;
          store_stmt = def_stmt;
        }
        }
    }
    }
 
 
  /* Alright then, we have visited all VUSEs of STMT and we've determined
  /* Alright then, we have visited all VUSEs of STMT and we've determined
     that all of them come from the same statement STORE_STMT.  See if there
     that all of them come from the same statement STORE_STMT.  See if there
     is a useful expression we can deduce from STORE_STMT.  */
     is a useful expression we can deduce from STORE_STMT.  */
  rhs = TREE_OPERAND (store_stmt, 1);
  rhs = TREE_OPERAND (store_stmt, 1);
  if ((TREE_CODE (rhs) == SSA_NAME
  if ((TREE_CODE (rhs) == SSA_NAME
       && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs))
       && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs))
      || is_gimple_min_invariant (rhs)
      || is_gimple_min_invariant (rhs)
      || TREE_CODE (rhs) == ADDR_EXPR
      || TREE_CODE (rhs) == ADDR_EXPR
      || TREE_INVARIANT (rhs))
      || TREE_INVARIANT (rhs))
    {
    {
 
 
      /* Yay!  Compute a value number for the RHS of the statement and
      /* Yay!  Compute a value number for the RHS of the statement and
         add its value to the AVAIL_OUT set for the block.  Add the LHS
         add its value to the AVAIL_OUT set for the block.  Add the LHS
         to TMP_GEN.  */
         to TMP_GEN.  */
      add_to_sets (lhs, rhs, store_stmt, TMP_GEN (block), AVAIL_OUT (block));
      add_to_sets (lhs, rhs, store_stmt, TMP_GEN (block), AVAIL_OUT (block));
      if (TREE_CODE (rhs) == SSA_NAME
      if (TREE_CODE (rhs) == SSA_NAME
          && !is_undefined_value (rhs))
          && !is_undefined_value (rhs))
        value_insert_into_set (EXP_GEN (block), rhs);
        value_insert_into_set (EXP_GEN (block), rhs);
      return true;
      return true;
    }
    }
 
 
  return false;
  return false;
}
}
 
 
/* Return a copy of NODE that is stored in the temporary alloc_pool's.
/* Return a copy of NODE that is stored in the temporary alloc_pool's.
   This is made recursively true, so that the operands are stored in
   This is made recursively true, so that the operands are stored in
   the pool as well.  */
   the pool as well.  */
 
 
static tree
static tree
poolify_tree (tree node)
poolify_tree (tree node)
{
{
  switch  (TREE_CODE (node))
  switch  (TREE_CODE (node))
    {
    {
    case INDIRECT_REF:
    case INDIRECT_REF:
      {
      {
        tree temp = pool_alloc (reference_node_pool);
        tree temp = pool_alloc (reference_node_pool);
        memcpy (temp, node, tree_size (node));
        memcpy (temp, node, tree_size (node));
        TREE_OPERAND (temp, 0) = poolify_tree (TREE_OPERAND (temp, 0));
        TREE_OPERAND (temp, 0) = poolify_tree (TREE_OPERAND (temp, 0));
        return temp;
        return temp;
      }
      }
      break;
      break;
    case MODIFY_EXPR:
    case MODIFY_EXPR:
      {
      {
        tree temp = pool_alloc (modify_expr_node_pool);
        tree temp = pool_alloc (modify_expr_node_pool);
        memcpy (temp, node, tree_size (node));
        memcpy (temp, node, tree_size (node));
        TREE_OPERAND (temp, 0) = poolify_tree (TREE_OPERAND (temp, 0));
        TREE_OPERAND (temp, 0) = poolify_tree (TREE_OPERAND (temp, 0));
        TREE_OPERAND (temp, 1) = poolify_tree (TREE_OPERAND (temp, 1));
        TREE_OPERAND (temp, 1) = poolify_tree (TREE_OPERAND (temp, 1));
        return temp;
        return temp;
      }
      }
      break;
      break;
    case SSA_NAME:
    case SSA_NAME:
    case INTEGER_CST:
    case INTEGER_CST:
    case STRING_CST:
    case STRING_CST:
    case REAL_CST:
    case REAL_CST:
    case PARM_DECL:
    case PARM_DECL:
    case VAR_DECL:
    case VAR_DECL:
    case RESULT_DECL:
    case RESULT_DECL:
      return node;
      return node;
    default:
    default:
      gcc_unreachable ();
      gcc_unreachable ();
    }
    }
}
}
 
 
static tree modify_expr_template;
static tree modify_expr_template;
 
 
/* Allocate a MODIFY_EXPR with TYPE, and operands OP1, OP2 in the
/* Allocate a MODIFY_EXPR with TYPE, and operands OP1, OP2 in the
   alloc pools and return it.  */
   alloc pools and return it.  */
static tree
static tree
poolify_modify_expr (tree type, tree op1, tree op2)
poolify_modify_expr (tree type, tree op1, tree op2)
{
{
  if (modify_expr_template == NULL)
  if (modify_expr_template == NULL)
    modify_expr_template = build2 (MODIFY_EXPR, type, op1, op2);
    modify_expr_template = build2 (MODIFY_EXPR, type, op1, op2);
 
 
  TREE_OPERAND (modify_expr_template, 0) = op1;
  TREE_OPERAND (modify_expr_template, 0) = op1;
  TREE_OPERAND (modify_expr_template, 1) = op2;
  TREE_OPERAND (modify_expr_template, 1) = op2;
  TREE_TYPE (modify_expr_template) = type;
  TREE_TYPE (modify_expr_template) = type;
 
 
  return poolify_tree (modify_expr_template);
  return poolify_tree (modify_expr_template);
}
}
 
 
 
 
/* For each real store operation of the form
/* For each real store operation of the form
   *a = <value> that we see, create a corresponding fake store of the
   *a = <value> that we see, create a corresponding fake store of the
   form storetmp_<version> = *a.
   form storetmp_<version> = *a.
 
 
   This enables AVAIL computation to mark the results of stores as
   This enables AVAIL computation to mark the results of stores as
   available.  Without this, you'd need to do some computation to
   available.  Without this, you'd need to do some computation to
   mark the result of stores as ANTIC and AVAIL at all the right
   mark the result of stores as ANTIC and AVAIL at all the right
   points.
   points.
   To save memory, we keep the store
   To save memory, we keep the store
   statements pool allocated until we decide whether they are
   statements pool allocated until we decide whether they are
   necessary or not.  */
   necessary or not.  */
 
 
static void
static void
insert_fake_stores (void)
insert_fake_stores (void)
{
{
  basic_block block;
  basic_block block;
 
 
  FOR_ALL_BB (block)
  FOR_ALL_BB (block)
    {
    {
      block_stmt_iterator bsi;
      block_stmt_iterator bsi;
      for (bsi = bsi_start (block); !bsi_end_p (bsi); bsi_next (&bsi))
      for (bsi = bsi_start (block); !bsi_end_p (bsi); bsi_next (&bsi))
        {
        {
          tree stmt = bsi_stmt (bsi);
          tree stmt = bsi_stmt (bsi);
 
 
          /* We can't generate SSA names for stores that are complex
          /* We can't generate SSA names for stores that are complex
             or aggregate.  We also want to ignore things whose
             or aggregate.  We also want to ignore things whose
             virtual uses occur in abnormal phis.  */
             virtual uses occur in abnormal phis.  */
 
 
          if (TREE_CODE (stmt) == MODIFY_EXPR
          if (TREE_CODE (stmt) == MODIFY_EXPR
              && TREE_CODE (TREE_OPERAND (stmt, 0)) == INDIRECT_REF
              && TREE_CODE (TREE_OPERAND (stmt, 0)) == INDIRECT_REF
              && !AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (stmt, 0)))
              && !AGGREGATE_TYPE_P (TREE_TYPE (TREE_OPERAND (stmt, 0)))
              && TREE_CODE (TREE_TYPE (TREE_OPERAND (stmt, 0))) != COMPLEX_TYPE)
              && TREE_CODE (TREE_TYPE (TREE_OPERAND (stmt, 0))) != COMPLEX_TYPE)
            {
            {
              ssa_op_iter iter;
              ssa_op_iter iter;
              def_operand_p defp;
              def_operand_p defp;
              tree lhs = TREE_OPERAND (stmt, 0);
              tree lhs = TREE_OPERAND (stmt, 0);
              tree rhs = TREE_OPERAND (stmt, 1);
              tree rhs = TREE_OPERAND (stmt, 1);
              tree new;
              tree new;
              bool notokay = false;
              bool notokay = false;
 
 
              FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_VIRTUAL_DEFS)
              FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_VIRTUAL_DEFS)
                {
                {
                  tree defvar = DEF_FROM_PTR (defp);
                  tree defvar = DEF_FROM_PTR (defp);
                  if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (defvar))
                  if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (defvar))
                    {
                    {
                      notokay = true;
                      notokay = true;
                      break;
                      break;
                    }
                    }
                }
                }
 
 
              if (notokay)
              if (notokay)
                continue;
                continue;
 
 
              if (!storetemp || TREE_TYPE (rhs) != TREE_TYPE (storetemp))
              if (!storetemp || TREE_TYPE (rhs) != TREE_TYPE (storetemp))
                {
                {
                  storetemp = create_tmp_var (TREE_TYPE (rhs), "storetmp");
                  storetemp = create_tmp_var (TREE_TYPE (rhs), "storetmp");
                  get_var_ann (storetemp);
                  get_var_ann (storetemp);
                }
                }
 
 
              new = poolify_modify_expr (TREE_TYPE (stmt), storetemp, lhs);
              new = poolify_modify_expr (TREE_TYPE (stmt), storetemp, lhs);
 
 
              lhs = make_ssa_name (storetemp, new);
              lhs = make_ssa_name (storetemp, new);
              TREE_OPERAND (new, 0) = lhs;
              TREE_OPERAND (new, 0) = lhs;
              create_ssa_artficial_load_stmt (new, stmt);
              create_ssa_artficial_load_stmt (new, stmt);
 
 
              NECESSARY (new) = 0;
              NECESSARY (new) = 0;
              VEC_safe_push (tree, heap, inserted_exprs, new);
              VEC_safe_push (tree, heap, inserted_exprs, new);
              VEC_safe_push (tree, heap, need_creation, new);
              VEC_safe_push (tree, heap, need_creation, new);
              bsi_insert_after (&bsi, new, BSI_NEW_STMT);
              bsi_insert_after (&bsi, new, BSI_NEW_STMT);
            }
            }
        }
        }
    }
    }
}
}
 
 
/* Turn the pool allocated fake stores that we created back into real
/* Turn the pool allocated fake stores that we created back into real
   GC allocated ones if they turned out to be necessary to PRE some
   GC allocated ones if they turned out to be necessary to PRE some
   expressions.  */
   expressions.  */
 
 
static void
static void
realify_fake_stores (void)
realify_fake_stores (void)
{
{
  unsigned int i;
  unsigned int i;
  tree stmt;
  tree stmt;
 
 
  for (i = 0; VEC_iterate (tree, need_creation, i, stmt); i++)
  for (i = 0; VEC_iterate (tree, need_creation, i, stmt); i++)
    {
    {
      if (NECESSARY (stmt))
      if (NECESSARY (stmt))
        {
        {
          block_stmt_iterator bsi;
          block_stmt_iterator bsi;
          tree newstmt;
          tree newstmt;
 
 
          /* Mark the temp variable as referenced */
          /* Mark the temp variable as referenced */
          add_referenced_var (SSA_NAME_VAR (TREE_OPERAND (stmt, 0)));
          add_referenced_var (SSA_NAME_VAR (TREE_OPERAND (stmt, 0)));
 
 
          /* Put the new statement in GC memory, fix up the
          /* Put the new statement in GC memory, fix up the
             SSA_NAME_DEF_STMT on it, and then put it in place of
             SSA_NAME_DEF_STMT on it, and then put it in place of
             the old statement before the store in the IR stream
             the old statement before the store in the IR stream
             as a plain ssa name copy.  */
             as a plain ssa name copy.  */
          bsi = bsi_for_stmt (stmt);
          bsi = bsi_for_stmt (stmt);
          bsi_prev (&bsi);
          bsi_prev (&bsi);
          newstmt = build2 (MODIFY_EXPR, void_type_node,
          newstmt = build2 (MODIFY_EXPR, void_type_node,
                            TREE_OPERAND (stmt, 0),
                            TREE_OPERAND (stmt, 0),
                            TREE_OPERAND (bsi_stmt (bsi), 1));
                            TREE_OPERAND (bsi_stmt (bsi), 1));
          SSA_NAME_DEF_STMT (TREE_OPERAND (newstmt, 0)) = newstmt;
          SSA_NAME_DEF_STMT (TREE_OPERAND (newstmt, 0)) = newstmt;
          bsi_insert_before (&bsi, newstmt, BSI_SAME_STMT);
          bsi_insert_before (&bsi, newstmt, BSI_SAME_STMT);
          bsi = bsi_for_stmt (stmt);
          bsi = bsi_for_stmt (stmt);
          bsi_remove (&bsi, true);
          bsi_remove (&bsi, true);
        }
        }
      else
      else
        release_defs (stmt);
        release_defs (stmt);
    }
    }
}
}
 
 
/* Tree-combine a value number expression *EXPR_P that does a type
/* Tree-combine a value number expression *EXPR_P that does a type
   conversion with the value number expression of its operand.
   conversion with the value number expression of its operand.
   Returns true, if *EXPR_P simplifies to a value number or
   Returns true, if *EXPR_P simplifies to a value number or
   gimple min-invariant expression different from EXPR_P and
   gimple min-invariant expression different from EXPR_P and
   sets *EXPR_P to the simplified expression value number.
   sets *EXPR_P to the simplified expression value number.
   Otherwise returns false and does not change *EXPR_P.  */
   Otherwise returns false and does not change *EXPR_P.  */
 
 
static bool
static bool
try_combine_conversion (tree *expr_p)
try_combine_conversion (tree *expr_p)
{
{
  tree expr = *expr_p;
  tree expr = *expr_p;
  tree t;
  tree t;
 
 
  if (!((TREE_CODE (expr) == NOP_EXPR
  if (!((TREE_CODE (expr) == NOP_EXPR
         || TREE_CODE (expr) == CONVERT_EXPR)
         || TREE_CODE (expr) == CONVERT_EXPR)
        && TREE_CODE (TREE_OPERAND (expr, 0)) == VALUE_HANDLE
        && TREE_CODE (TREE_OPERAND (expr, 0)) == VALUE_HANDLE
        && !VALUE_HANDLE_VUSES (TREE_OPERAND (expr, 0))))
        && !VALUE_HANDLE_VUSES (TREE_OPERAND (expr, 0))))
    return false;
    return false;
 
 
  t = fold_unary (TREE_CODE (expr), TREE_TYPE (expr),
  t = fold_unary (TREE_CODE (expr), TREE_TYPE (expr),
                  VALUE_HANDLE_EXPR_SET (TREE_OPERAND (expr, 0))->head->expr);
                  VALUE_HANDLE_EXPR_SET (TREE_OPERAND (expr, 0))->head->expr);
  if (!t)
  if (!t)
    return false;
    return false;
 
 
  /* Strip useless type conversions, which is safe in the optimizers but
  /* Strip useless type conversions, which is safe in the optimizers but
     not generally in fold.  */
     not generally in fold.  */
  STRIP_USELESS_TYPE_CONVERSION (t);
  STRIP_USELESS_TYPE_CONVERSION (t);
 
 
  /* Disallow value expressions we have no value number for already, as
  /* Disallow value expressions we have no value number for already, as
     we would miss a leader for it here.  */
     we would miss a leader for it here.  */
  if (!(TREE_CODE (t) == VALUE_HANDLE
  if (!(TREE_CODE (t) == VALUE_HANDLE
        || is_gimple_min_invariant (t)))
        || is_gimple_min_invariant (t)))
    t = vn_lookup (t, NULL);
    t = vn_lookup (t, NULL);
 
 
  if (t && t != expr)
  if (t && t != expr)
    {
    {
      *expr_p = t;
      *expr_p = t;
      return true;
      return true;
    }
    }
  return false;
  return false;
}
}
 
 
/* Compute the AVAIL set for all basic blocks.
/* Compute the AVAIL set for all basic blocks.
 
 
   This function performs value numbering of the statements in each basic
   This function performs value numbering of the statements in each basic
   block.  The AVAIL sets are built from information we glean while doing
   block.  The AVAIL sets are built from information we glean while doing
   this value numbering, since the AVAIL sets contain only one entry per
   this value numbering, since the AVAIL sets contain only one entry per
   value.
   value.
 
 
   AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
   AVAIL_IN[BLOCK] = AVAIL_OUT[dom(BLOCK)].
   AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK].  */
   AVAIL_OUT[BLOCK] = AVAIL_IN[BLOCK] U PHI_GEN[BLOCK] U TMP_GEN[BLOCK].  */
 
 
static void
static void
compute_avail (void)
compute_avail (void)
{
{
  basic_block block, son;
  basic_block block, son;
  basic_block *worklist;
  basic_block *worklist;
  size_t sp = 0;
  size_t sp = 0;
  tree param;
  tree param;
  /* For arguments with default definitions, we pretend they are
  /* For arguments with default definitions, we pretend they are
     defined in the entry block.  */
     defined in the entry block.  */
  for (param = DECL_ARGUMENTS (current_function_decl);
  for (param = DECL_ARGUMENTS (current_function_decl);
       param;
       param;
       param = TREE_CHAIN (param))
       param = TREE_CHAIN (param))
    {
    {
      if (default_def (param) != NULL)
      if (default_def (param) != NULL)
        {
        {
          tree def = default_def (param);
          tree def = default_def (param);
          vn_lookup_or_add (def, NULL);
          vn_lookup_or_add (def, NULL);
          bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR), def);
          bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR), def);
          bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR), def);
          bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR), def);
        }
        }
    }
    }
 
 
  /* Likewise for the static chain decl. */
  /* Likewise for the static chain decl. */
  if (cfun->static_chain_decl)
  if (cfun->static_chain_decl)
    {
    {
      param = cfun->static_chain_decl;
      param = cfun->static_chain_decl;
      if (default_def (param) != NULL)
      if (default_def (param) != NULL)
        {
        {
          tree def = default_def (param);
          tree def = default_def (param);
          vn_lookup_or_add (def, NULL);
          vn_lookup_or_add (def, NULL);
          bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR), def);
          bitmap_insert_into_set (TMP_GEN (ENTRY_BLOCK_PTR), def);
          bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR), def);
          bitmap_value_insert_into_set (AVAIL_OUT (ENTRY_BLOCK_PTR), def);
        }
        }
    }
    }
 
 
  /* Allocate the worklist.  */
  /* Allocate the worklist.  */
  worklist = XNEWVEC (basic_block, n_basic_blocks);
  worklist = XNEWVEC (basic_block, n_basic_blocks);
 
 
  /* Seed the algorithm by putting the dominator children of the entry
  /* Seed the algorithm by putting the dominator children of the entry
     block on the worklist.  */
     block on the worklist.  */
  for (son = first_dom_son (CDI_DOMINATORS, ENTRY_BLOCK_PTR);
  for (son = first_dom_son (CDI_DOMINATORS, ENTRY_BLOCK_PTR);
       son;
       son;
       son = next_dom_son (CDI_DOMINATORS, son))
       son = next_dom_son (CDI_DOMINATORS, son))
    worklist[sp++] = son;
    worklist[sp++] = son;
 
 
  /* Loop until the worklist is empty.  */
  /* Loop until the worklist is empty.  */
  while (sp)
  while (sp)
    {
    {
      block_stmt_iterator bsi;
      block_stmt_iterator bsi;
      tree stmt, phi;
      tree stmt, phi;
      basic_block dom;
      basic_block dom;
      unsigned int stmt_uid = 1;
      unsigned int stmt_uid = 1;
 
 
      /* Pick a block from the worklist.  */
      /* Pick a block from the worklist.  */
      block = worklist[--sp];
      block = worklist[--sp];
 
 
      /* Initially, the set of available values in BLOCK is that of
      /* Initially, the set of available values in BLOCK is that of
         its immediate dominator.  */
         its immediate dominator.  */
      dom = get_immediate_dominator (CDI_DOMINATORS, block);
      dom = get_immediate_dominator (CDI_DOMINATORS, block);
      if (dom)
      if (dom)
        bitmap_set_copy (AVAIL_OUT (block), AVAIL_OUT (dom));
        bitmap_set_copy (AVAIL_OUT (block), AVAIL_OUT (dom));
 
 
      if (!in_fre)
      if (!in_fre)
        insert_extra_phis (block, dom);
        insert_extra_phis (block, dom);
 
 
      /* Generate values for PHI nodes.  */
      /* Generate values for PHI nodes.  */
      for (phi = phi_nodes (block); phi; phi = PHI_CHAIN (phi))
      for (phi = phi_nodes (block); phi; phi = PHI_CHAIN (phi))
        /* We have no need for virtual phis, as they don't represent
        /* We have no need for virtual phis, as they don't represent
           actual computations.  */
           actual computations.  */
        if (is_gimple_reg (PHI_RESULT (phi)))
        if (is_gimple_reg (PHI_RESULT (phi)))
          add_to_sets (PHI_RESULT (phi), PHI_RESULT (phi), NULL,
          add_to_sets (PHI_RESULT (phi), PHI_RESULT (phi), NULL,
                       PHI_GEN (block), AVAIL_OUT (block));
                       PHI_GEN (block), AVAIL_OUT (block));
 
 
      /* Now compute value numbers and populate value sets with all
      /* Now compute value numbers and populate value sets with all
         the expressions computed in BLOCK.  */
         the expressions computed in BLOCK.  */
      for (bsi = bsi_start (block); !bsi_end_p (bsi); bsi_next (&bsi))
      for (bsi = bsi_start (block); !bsi_end_p (bsi); bsi_next (&bsi))
        {
        {
          stmt_ann_t ann;
          stmt_ann_t ann;
          ssa_op_iter iter;
          ssa_op_iter iter;
          tree op;
          tree op;
 
 
          stmt = bsi_stmt (bsi);
          stmt = bsi_stmt (bsi);
          ann = stmt_ann (stmt);
          ann = stmt_ann (stmt);
 
 
          ann->uid = stmt_uid++;
          ann->uid = stmt_uid++;
 
 
          /* For regular value numbering, we are only interested in
          /* For regular value numbering, we are only interested in
             assignments of the form X_i = EXPR, where EXPR represents
             assignments of the form X_i = EXPR, where EXPR represents
             an "interesting" computation, it has no volatile operands
             an "interesting" computation, it has no volatile operands
             and X_i doesn't flow through an abnormal edge.  */
             and X_i doesn't flow through an abnormal edge.  */
          if (TREE_CODE (stmt) == MODIFY_EXPR
          if (TREE_CODE (stmt) == MODIFY_EXPR
              && !ann->has_volatile_ops
              && !ann->has_volatile_ops
              && TREE_CODE (TREE_OPERAND (stmt, 0)) == SSA_NAME
              && TREE_CODE (TREE_OPERAND (stmt, 0)) == SSA_NAME
              && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (TREE_OPERAND (stmt, 0)))
              && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (TREE_OPERAND (stmt, 0)))
            {
            {
              tree lhs = TREE_OPERAND (stmt, 0);
              tree lhs = TREE_OPERAND (stmt, 0);
              tree rhs = TREE_OPERAND (stmt, 1);
              tree rhs = TREE_OPERAND (stmt, 1);
 
 
              /* Try to look through loads.  */
              /* Try to look through loads.  */
              if (TREE_CODE (lhs) == SSA_NAME
              if (TREE_CODE (lhs) == SSA_NAME
                  && !ZERO_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_USES)
                  && !ZERO_SSA_OPERANDS (stmt, SSA_OP_VIRTUAL_USES)
                  && try_look_through_load (lhs, rhs, stmt, block))
                  && try_look_through_load (lhs, rhs, stmt, block))
                continue;
                continue;
 
 
              STRIP_USELESS_TYPE_CONVERSION (rhs);
              STRIP_USELESS_TYPE_CONVERSION (rhs);
              if (can_value_number_operation (rhs))
              if (can_value_number_operation (rhs))
                {
                {
                  /* For value numberable operation, create a
                  /* For value numberable operation, create a
                     duplicate expression with the operands replaced
                     duplicate expression with the operands replaced
                     with the value handles of the original RHS.  */
                     with the value handles of the original RHS.  */
                  tree newt = create_value_expr_from (rhs, block, stmt);
                  tree newt = create_value_expr_from (rhs, block, stmt);
                  if (newt)
                  if (newt)
                    {
                    {
                      /* If we can combine a conversion expression
                      /* If we can combine a conversion expression
                         with the expression for its operand just
                         with the expression for its operand just
                         record the value number for it.  */
                         record the value number for it.  */
                      if (try_combine_conversion (&newt))
                      if (try_combine_conversion (&newt))
                        vn_add (lhs, newt);
                        vn_add (lhs, newt);
                      else
                      else
                        {
                        {
                          tree val = vn_lookup_or_add (newt, stmt);
                          tree val = vn_lookup_or_add (newt, stmt);
                          vn_add (lhs, val);
                          vn_add (lhs, val);
                          value_insert_into_set (EXP_GEN (block), newt);
                          value_insert_into_set (EXP_GEN (block), newt);
                        }
                        }
                      bitmap_insert_into_set (TMP_GEN (block), lhs);
                      bitmap_insert_into_set (TMP_GEN (block), lhs);
                      bitmap_value_insert_into_set (AVAIL_OUT (block), lhs);
                      bitmap_value_insert_into_set (AVAIL_OUT (block), lhs);
                      continue;
                      continue;
                    }
                    }
                }
                }
              else if ((TREE_CODE (rhs) == SSA_NAME
              else if ((TREE_CODE (rhs) == SSA_NAME
                        && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs))
                        && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (rhs))
                       || is_gimple_min_invariant (rhs)
                       || is_gimple_min_invariant (rhs)
                       || TREE_CODE (rhs) == ADDR_EXPR
                       || TREE_CODE (rhs) == ADDR_EXPR
                       || TREE_INVARIANT (rhs)
                       || TREE_INVARIANT (rhs)
                       || DECL_P (rhs))
                       || DECL_P (rhs))
                {
                {
                  /* Compute a value number for the RHS of the statement
                  /* Compute a value number for the RHS of the statement
                     and add its value to the AVAIL_OUT set for the block.
                     and add its value to the AVAIL_OUT set for the block.
                     Add the LHS to TMP_GEN.  */
                     Add the LHS to TMP_GEN.  */
                  add_to_sets (lhs, rhs, stmt, TMP_GEN (block),
                  add_to_sets (lhs, rhs, stmt, TMP_GEN (block),
                               AVAIL_OUT (block));
                               AVAIL_OUT (block));
 
 
                  if (TREE_CODE (rhs) == SSA_NAME
                  if (TREE_CODE (rhs) == SSA_NAME
                      && !is_undefined_value (rhs))
                      && !is_undefined_value (rhs))
                    value_insert_into_set (EXP_GEN (block), rhs);
                    value_insert_into_set (EXP_GEN (block), rhs);
                  continue;
                  continue;
                }
                }
            }
            }
 
 
          /* For any other statement that we don't recognize, simply
          /* For any other statement that we don't recognize, simply
             make the names generated by the statement available in
             make the names generated by the statement available in
             AVAIL_OUT and TMP_GEN.  */
             AVAIL_OUT and TMP_GEN.  */
          FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_DEF)
          FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_DEF)
            add_to_sets (op, op, NULL, TMP_GEN (block), AVAIL_OUT (block));
            add_to_sets (op, op, NULL, TMP_GEN (block), AVAIL_OUT (block));
 
 
          FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE)
          FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE)
            add_to_sets (op, op, NULL, NULL , AVAIL_OUT (block));
            add_to_sets (op, op, NULL, NULL , AVAIL_OUT (block));
        }
        }
 
 
      /* Put the dominator children of BLOCK on the worklist of blocks
      /* Put the dominator children of BLOCK on the worklist of blocks
         to compute available sets for.  */
         to compute available sets for.  */
      for (son = first_dom_son (CDI_DOMINATORS, block);
      for (son = first_dom_son (CDI_DOMINATORS, block);
           son;
           son;
           son = next_dom_son (CDI_DOMINATORS, son))
           son = next_dom_son (CDI_DOMINATORS, son))
        worklist[sp++] = son;
        worklist[sp++] = son;
    }
    }
 
 
  free (worklist);
  free (worklist);
}
}
 
 
 
 
/* Eliminate fully redundant computations.  */
/* Eliminate fully redundant computations.  */
 
 
static void
static void
eliminate (void)
eliminate (void)
{
{
  basic_block b;
  basic_block b;
 
 
  FOR_EACH_BB (b)
  FOR_EACH_BB (b)
    {
    {
      block_stmt_iterator i;
      block_stmt_iterator i;
 
 
      for (i = bsi_start (b); !bsi_end_p (i); bsi_next (&i))
      for (i = bsi_start (b); !bsi_end_p (i); bsi_next (&i))
        {
        {
          tree stmt = bsi_stmt (i);
          tree stmt = bsi_stmt (i);
 
 
          /* Lookup the RHS of the expression, see if we have an
          /* Lookup the RHS of the expression, see if we have an
             available computation for it.  If so, replace the RHS with
             available computation for it.  If so, replace the RHS with
             the available computation.  */
             the available computation.  */
          if (TREE_CODE (stmt) == MODIFY_EXPR
          if (TREE_CODE (stmt) == MODIFY_EXPR
              && TREE_CODE (TREE_OPERAND (stmt, 0)) == SSA_NAME
              && TREE_CODE (TREE_OPERAND (stmt, 0)) == SSA_NAME
              && TREE_CODE (TREE_OPERAND (stmt ,1)) != SSA_NAME
              && TREE_CODE (TREE_OPERAND (stmt ,1)) != SSA_NAME
              && !is_gimple_min_invariant (TREE_OPERAND (stmt, 1))
              && !is_gimple_min_invariant (TREE_OPERAND (stmt, 1))
              && !stmt_ann (stmt)->has_volatile_ops)
              && !stmt_ann (stmt)->has_volatile_ops)
            {
            {
              tree lhs = TREE_OPERAND (stmt, 0);
              tree lhs = TREE_OPERAND (stmt, 0);
              tree *rhs_p = &TREE_OPERAND (stmt, 1);
              tree *rhs_p = &TREE_OPERAND (stmt, 1);
              tree sprime;
              tree sprime;
 
 
              sprime = bitmap_find_leader (AVAIL_OUT (b),
              sprime = bitmap_find_leader (AVAIL_OUT (b),
                                           vn_lookup (lhs, NULL));
                                           vn_lookup (lhs, NULL));
              if (sprime
              if (sprime
                  && sprime != lhs
                  && sprime != lhs
                  && (TREE_CODE (*rhs_p) != SSA_NAME
                  && (TREE_CODE (*rhs_p) != SSA_NAME
                      || may_propagate_copy (*rhs_p, sprime)))
                      || may_propagate_copy (*rhs_p, sprime)))
                {
                {
                  gcc_assert (sprime != *rhs_p);
                  gcc_assert (sprime != *rhs_p);
 
 
                  if (dump_file && (dump_flags & TDF_DETAILS))
                  if (dump_file && (dump_flags & TDF_DETAILS))
                    {
                    {
                      fprintf (dump_file, "Replaced ");
                      fprintf (dump_file, "Replaced ");
                      print_generic_expr (dump_file, *rhs_p, 0);
                      print_generic_expr (dump_file, *rhs_p, 0);
                      fprintf (dump_file, " with ");
                      fprintf (dump_file, " with ");
                      print_generic_expr (dump_file, sprime, 0);
                      print_generic_expr (dump_file, sprime, 0);
                      fprintf (dump_file, " in ");
                      fprintf (dump_file, " in ");
                      print_generic_stmt (dump_file, stmt, 0);
                      print_generic_stmt (dump_file, stmt, 0);
                    }
                    }
 
 
                  if (TREE_CODE (sprime) == SSA_NAME)
                  if (TREE_CODE (sprime) == SSA_NAME)
                    NECESSARY (SSA_NAME_DEF_STMT (sprime)) = 1;
                    NECESSARY (SSA_NAME_DEF_STMT (sprime)) = 1;
                  /* We need to make sure the new and old types actually match,
                  /* We need to make sure the new and old types actually match,
                     which may require adding a simple cast, which fold_convert
                     which may require adding a simple cast, which fold_convert
                     will do for us.  */
                     will do for us.  */
                  if (TREE_CODE (*rhs_p) != SSA_NAME
                  if (TREE_CODE (*rhs_p) != SSA_NAME
                      && !tree_ssa_useless_type_conversion_1 (TREE_TYPE (*rhs_p),
                      && !tree_ssa_useless_type_conversion_1 (TREE_TYPE (*rhs_p),
                                                              TREE_TYPE (sprime)))
                                                              TREE_TYPE (sprime)))
                    sprime = fold_convert (TREE_TYPE (*rhs_p), sprime);
                    sprime = fold_convert (TREE_TYPE (*rhs_p), sprime);
 
 
                  pre_stats.eliminations++;
                  pre_stats.eliminations++;
                  propagate_tree_value (rhs_p, sprime);
                  propagate_tree_value (rhs_p, sprime);
                  update_stmt (stmt);
                  update_stmt (stmt);
 
 
                  /* If we removed EH side effects from the statement, clean
                  /* If we removed EH side effects from the statement, clean
                     its EH information.  */
                     its EH information.  */
                  if (maybe_clean_or_replace_eh_stmt (stmt, stmt))
                  if (maybe_clean_or_replace_eh_stmt (stmt, stmt))
                    {
                    {
                      bitmap_set_bit (need_eh_cleanup,
                      bitmap_set_bit (need_eh_cleanup,
                                      bb_for_stmt (stmt)->index);
                                      bb_for_stmt (stmt)->index);
                      if (dump_file && (dump_flags & TDF_DETAILS))
                      if (dump_file && (dump_flags & TDF_DETAILS))
                        fprintf (dump_file, "  Removed EH side effects.\n");
                        fprintf (dump_file, "  Removed EH side effects.\n");
                    }
                    }
                }
                }
            }
            }
        }
        }
    }
    }
}
}
 
 
/* Borrow a bit of tree-ssa-dce.c for the moment.
/* Borrow a bit of tree-ssa-dce.c for the moment.
   XXX: In 4.1, we should be able to just run a DCE pass after PRE, though
   XXX: In 4.1, we should be able to just run a DCE pass after PRE, though
   this may be a bit faster, and we may want critical edges kept split.  */
   this may be a bit faster, and we may want critical edges kept split.  */
 
 
/* If OP's defining statement has not already been determined to be necessary,
/* If OP's defining statement has not already been determined to be necessary,
   mark that statement necessary. Return the stmt, if it is newly
   mark that statement necessary. Return the stmt, if it is newly
   necessary.  */
   necessary.  */
 
 
static inline tree
static inline tree
mark_operand_necessary (tree op)
mark_operand_necessary (tree op)
{
{
  tree stmt;
  tree stmt;
 
 
  gcc_assert (op);
  gcc_assert (op);
 
 
  if (TREE_CODE (op) != SSA_NAME)
  if (TREE_CODE (op) != SSA_NAME)
    return NULL;
    return NULL;
 
 
  stmt = SSA_NAME_DEF_STMT (op);
  stmt = SSA_NAME_DEF_STMT (op);
  gcc_assert (stmt);
  gcc_assert (stmt);
 
 
  if (NECESSARY (stmt)
  if (NECESSARY (stmt)
      || IS_EMPTY_STMT (stmt))
      || IS_EMPTY_STMT (stmt))
    return NULL;
    return NULL;
 
 
  NECESSARY (stmt) = 1;
  NECESSARY (stmt) = 1;
  return stmt;
  return stmt;
}
}
 
 
/* Because we don't follow exactly the standard PRE algorithm, and decide not
/* Because we don't follow exactly the standard PRE algorithm, and decide not
   to insert PHI nodes sometimes, and because value numbering of casts isn't
   to insert PHI nodes sometimes, and because value numbering of casts isn't
   perfect, we sometimes end up inserting dead code.   This simple DCE-like
   perfect, we sometimes end up inserting dead code.   This simple DCE-like
   pass removes any insertions we made that weren't actually used.  */
   pass removes any insertions we made that weren't actually used.  */
 
 
static void
static void
remove_dead_inserted_code (void)
remove_dead_inserted_code (void)
{
{
  VEC(tree,heap) *worklist = NULL;
  VEC(tree,heap) *worklist = NULL;
  int i;
  int i;
  tree t;
  tree t;
 
 
  worklist = VEC_alloc (tree, heap, VEC_length (tree, inserted_exprs));
  worklist = VEC_alloc (tree, heap, VEC_length (tree, inserted_exprs));
  for (i = 0; VEC_iterate (tree, inserted_exprs, i, t); i++)
  for (i = 0; VEC_iterate (tree, inserted_exprs, i, t); i++)
    {
    {
      if (NECESSARY (t))
      if (NECESSARY (t))
        VEC_quick_push (tree, worklist, t);
        VEC_quick_push (tree, worklist, t);
    }
    }
  while (VEC_length (tree, worklist) > 0)
  while (VEC_length (tree, worklist) > 0)
    {
    {
      t = VEC_pop (tree, worklist);
      t = VEC_pop (tree, worklist);
 
 
      /* PHI nodes are somewhat special in that each PHI alternative has
      /* PHI nodes are somewhat special in that each PHI alternative has
         data and control dependencies.  All the statements feeding the
         data and control dependencies.  All the statements feeding the
         PHI node's arguments are always necessary. */
         PHI node's arguments are always necessary. */
      if (TREE_CODE (t) == PHI_NODE)
      if (TREE_CODE (t) == PHI_NODE)
        {
        {
          int k;
          int k;
 
 
          VEC_reserve (tree, heap, worklist, PHI_NUM_ARGS (t));
          VEC_reserve (tree, heap, worklist, PHI_NUM_ARGS (t));
          for (k = 0; k < PHI_NUM_ARGS (t); k++)
          for (k = 0; k < PHI_NUM_ARGS (t); k++)
            {
            {
              tree arg = PHI_ARG_DEF (t, k);
              tree arg = PHI_ARG_DEF (t, k);
              if (TREE_CODE (arg) == SSA_NAME)
              if (TREE_CODE (arg) == SSA_NAME)
                {
                {
                  arg = mark_operand_necessary (arg);
                  arg = mark_operand_necessary (arg);
                  if (arg)
                  if (arg)
                    VEC_quick_push (tree, worklist, arg);
                    VEC_quick_push (tree, worklist, arg);
                }
                }
            }
            }
        }
        }
      else
      else
        {
        {
          /* Propagate through the operands.  Examine all the USE, VUSE and
          /* Propagate through the operands.  Examine all the USE, VUSE and
             V_MAY_DEF operands in this statement.  Mark all the statements
             V_MAY_DEF operands in this statement.  Mark all the statements
             which feed this statement's uses as necessary.  */
             which feed this statement's uses as necessary.  */
          ssa_op_iter iter;
          ssa_op_iter iter;
          tree use;
          tree use;
 
 
          /* The operands of V_MAY_DEF expressions are also needed as they
          /* The operands of V_MAY_DEF expressions are also needed as they
             represent potential definitions that may reach this
             represent potential definitions that may reach this
             statement (V_MAY_DEF operands allow us to follow def-def
             statement (V_MAY_DEF operands allow us to follow def-def
             links).  */
             links).  */
 
 
          FOR_EACH_SSA_TREE_OPERAND (use, t, iter, SSA_OP_ALL_USES)
          FOR_EACH_SSA_TREE_OPERAND (use, t, iter, SSA_OP_ALL_USES)
            {
            {
              tree n = mark_operand_necessary (use);
              tree n = mark_operand_necessary (use);
              if (n)
              if (n)
                VEC_safe_push (tree, heap, worklist, n);
                VEC_safe_push (tree, heap, worklist, n);
            }
            }
        }
        }
    }
    }
 
 
  for (i = 0; VEC_iterate (tree, inserted_exprs, i, t); i++)
  for (i = 0; VEC_iterate (tree, inserted_exprs, i, t); i++)
    {
    {
      if (!NECESSARY (t))
      if (!NECESSARY (t))
        {
        {
          block_stmt_iterator bsi;
          block_stmt_iterator bsi;
 
 
          if (dump_file && (dump_flags & TDF_DETAILS))
          if (dump_file && (dump_flags & TDF_DETAILS))
            {
            {
              fprintf (dump_file, "Removing unnecessary insertion:");
              fprintf (dump_file, "Removing unnecessary insertion:");
              print_generic_stmt (dump_file, t, 0);
              print_generic_stmt (dump_file, t, 0);
            }
            }
 
 
          if (TREE_CODE (t) == PHI_NODE)
          if (TREE_CODE (t) == PHI_NODE)
            {
            {
              remove_phi_node (t, NULL);
              remove_phi_node (t, NULL);
            }
            }
          else
          else
            {
            {
              bsi = bsi_for_stmt (t);
              bsi = bsi_for_stmt (t);
              bsi_remove (&bsi, true);
              bsi_remove (&bsi, true);
              release_defs (t);
              release_defs (t);
            }
            }
        }
        }
    }
    }
  VEC_free (tree, heap, worklist);
  VEC_free (tree, heap, worklist);
}
}
 
 
/* Initialize data structures used by PRE.  */
/* Initialize data structures used by PRE.  */
 
 
static void
static void
init_pre (bool do_fre)
init_pre (bool do_fre)
{
{
  basic_block bb;
  basic_block bb;
 
 
  in_fre = do_fre;
  in_fre = do_fre;
 
 
  inserted_exprs = NULL;
  inserted_exprs = NULL;
  need_creation = NULL;
  need_creation = NULL;
  pretemp = NULL_TREE;
  pretemp = NULL_TREE;
  storetemp = NULL_TREE;
  storetemp = NULL_TREE;
  mergephitemp = NULL_TREE;
  mergephitemp = NULL_TREE;
  prephitemp = NULL_TREE;
  prephitemp = NULL_TREE;
 
 
  vn_init ();
  vn_init ();
  if (!do_fre)
  if (!do_fre)
    current_loops = loop_optimizer_init (LOOPS_NORMAL);
    current_loops = loop_optimizer_init (LOOPS_NORMAL);
 
 
  connect_infinite_loops_to_exit ();
  connect_infinite_loops_to_exit ();
  memset (&pre_stats, 0, sizeof (pre_stats));
  memset (&pre_stats, 0, sizeof (pre_stats));
 
 
  /* If block 0 has more than one predecessor, it means that its PHI
  /* If block 0 has more than one predecessor, it means that its PHI
     nodes will have arguments coming from block -1.  This creates
     nodes will have arguments coming from block -1.  This creates
     problems for several places in PRE that keep local arrays indexed
     problems for several places in PRE that keep local arrays indexed
     by block number.  To prevent this, we split the edge coming from
     by block number.  To prevent this, we split the edge coming from
     ENTRY_BLOCK_PTR (FIXME, if ENTRY_BLOCK_PTR had an index number
     ENTRY_BLOCK_PTR (FIXME, if ENTRY_BLOCK_PTR had an index number
     different than -1 we wouldn't have to hack this.  tree-ssa-dce.c
     different than -1 we wouldn't have to hack this.  tree-ssa-dce.c
     needs a similar change).  */
     needs a similar change).  */
  if (!single_pred_p (single_succ (ENTRY_BLOCK_PTR)))
  if (!single_pred_p (single_succ (ENTRY_BLOCK_PTR)))
    if (!(single_succ_edge (ENTRY_BLOCK_PTR)->flags & EDGE_ABNORMAL))
    if (!(single_succ_edge (ENTRY_BLOCK_PTR)->flags & EDGE_ABNORMAL))
      split_edge (single_succ_edge (ENTRY_BLOCK_PTR));
      split_edge (single_succ_edge (ENTRY_BLOCK_PTR));
 
 
  FOR_ALL_BB (bb)
  FOR_ALL_BB (bb)
    bb->aux = xcalloc (1, sizeof (struct bb_value_sets));
    bb->aux = xcalloc (1, sizeof (struct bb_value_sets));
 
 
  bitmap_obstack_initialize (&grand_bitmap_obstack);
  bitmap_obstack_initialize (&grand_bitmap_obstack);
  phi_translate_table = htab_create (511, expr_pred_trans_hash,
  phi_translate_table = htab_create (511, expr_pred_trans_hash,
                                     expr_pred_trans_eq, free);
                                     expr_pred_trans_eq, free);
  value_set_pool = create_alloc_pool ("Value sets",
  value_set_pool = create_alloc_pool ("Value sets",
                                      sizeof (struct value_set), 30);
                                      sizeof (struct value_set), 30);
  bitmap_set_pool = create_alloc_pool ("Bitmap sets",
  bitmap_set_pool = create_alloc_pool ("Bitmap sets",
                                       sizeof (struct bitmap_set), 30);
                                       sizeof (struct bitmap_set), 30);
  value_set_node_pool = create_alloc_pool ("Value set nodes",
  value_set_node_pool = create_alloc_pool ("Value set nodes",
                                           sizeof (struct value_set_node), 30);
                                           sizeof (struct value_set_node), 30);
  calculate_dominance_info (CDI_POST_DOMINATORS);
  calculate_dominance_info (CDI_POST_DOMINATORS);
  calculate_dominance_info (CDI_DOMINATORS);
  calculate_dominance_info (CDI_DOMINATORS);
  binary_node_pool = create_alloc_pool ("Binary tree nodes",
  binary_node_pool = create_alloc_pool ("Binary tree nodes",
                                        tree_code_size (PLUS_EXPR), 30);
                                        tree_code_size (PLUS_EXPR), 30);
  unary_node_pool = create_alloc_pool ("Unary tree nodes",
  unary_node_pool = create_alloc_pool ("Unary tree nodes",
                                       tree_code_size (NEGATE_EXPR), 30);
                                       tree_code_size (NEGATE_EXPR), 30);
  reference_node_pool = create_alloc_pool ("Reference tree nodes",
  reference_node_pool = create_alloc_pool ("Reference tree nodes",
                                           tree_code_size (ARRAY_REF), 30);
                                           tree_code_size (ARRAY_REF), 30);
  expression_node_pool = create_alloc_pool ("Expression tree nodes",
  expression_node_pool = create_alloc_pool ("Expression tree nodes",
                                            tree_code_size (CALL_EXPR), 30);
                                            tree_code_size (CALL_EXPR), 30);
  list_node_pool = create_alloc_pool ("List tree nodes",
  list_node_pool = create_alloc_pool ("List tree nodes",
                                      tree_code_size (TREE_LIST), 30);
                                      tree_code_size (TREE_LIST), 30);
  comparison_node_pool = create_alloc_pool ("Comparison tree nodes",
  comparison_node_pool = create_alloc_pool ("Comparison tree nodes",
                                            tree_code_size (EQ_EXPR), 30);
                                            tree_code_size (EQ_EXPR), 30);
  modify_expr_node_pool = create_alloc_pool ("MODIFY_EXPR nodes",
  modify_expr_node_pool = create_alloc_pool ("MODIFY_EXPR nodes",
                                             tree_code_size (MODIFY_EXPR),
                                             tree_code_size (MODIFY_EXPR),
                                             30);
                                             30);
  modify_expr_template = NULL;
  modify_expr_template = NULL;
 
 
  FOR_ALL_BB (bb)
  FOR_ALL_BB (bb)
    {
    {
      EXP_GEN (bb) = set_new (true);
      EXP_GEN (bb) = set_new (true);
      PHI_GEN (bb) = bitmap_set_new ();
      PHI_GEN (bb) = bitmap_set_new ();
      TMP_GEN (bb) = bitmap_set_new ();
      TMP_GEN (bb) = bitmap_set_new ();
      AVAIL_OUT (bb) = bitmap_set_new ();
      AVAIL_OUT (bb) = bitmap_set_new ();
    }
    }
 
 
  need_eh_cleanup = BITMAP_ALLOC (NULL);
  need_eh_cleanup = BITMAP_ALLOC (NULL);
}
}
 
 
 
 
/* Deallocate data structures used by PRE.  */
/* Deallocate data structures used by PRE.  */
 
 
static void
static void
fini_pre (bool do_fre)
fini_pre (bool do_fre)
{
{
  basic_block bb;
  basic_block bb;
  unsigned int i;
  unsigned int i;
 
 
  VEC_free (tree, heap, inserted_exprs);
  VEC_free (tree, heap, inserted_exprs);
  VEC_free (tree, heap, need_creation);
  VEC_free (tree, heap, need_creation);
  bitmap_obstack_release (&grand_bitmap_obstack);
  bitmap_obstack_release (&grand_bitmap_obstack);
  free_alloc_pool (value_set_pool);
  free_alloc_pool (value_set_pool);
  free_alloc_pool (bitmap_set_pool);
  free_alloc_pool (bitmap_set_pool);
  free_alloc_pool (value_set_node_pool);
  free_alloc_pool (value_set_node_pool);
  free_alloc_pool (binary_node_pool);
  free_alloc_pool (binary_node_pool);
  free_alloc_pool (reference_node_pool);
  free_alloc_pool (reference_node_pool);
  free_alloc_pool (unary_node_pool);
  free_alloc_pool (unary_node_pool);
  free_alloc_pool (list_node_pool);
  free_alloc_pool (list_node_pool);
  free_alloc_pool (expression_node_pool);
  free_alloc_pool (expression_node_pool);
  free_alloc_pool (comparison_node_pool);
  free_alloc_pool (comparison_node_pool);
  free_alloc_pool (modify_expr_node_pool);
  free_alloc_pool (modify_expr_node_pool);
  htab_delete (phi_translate_table);
  htab_delete (phi_translate_table);
  remove_fake_exit_edges ();
  remove_fake_exit_edges ();
 
 
  FOR_ALL_BB (bb)
  FOR_ALL_BB (bb)
    {
    {
      free (bb->aux);
      free (bb->aux);
      bb->aux = NULL;
      bb->aux = NULL;
    }
    }
 
 
  free_dominance_info (CDI_POST_DOMINATORS);
  free_dominance_info (CDI_POST_DOMINATORS);
  vn_delete ();
  vn_delete ();
 
 
  if (!bitmap_empty_p (need_eh_cleanup))
  if (!bitmap_empty_p (need_eh_cleanup))
    {
    {
      tree_purge_all_dead_eh_edges (need_eh_cleanup);
      tree_purge_all_dead_eh_edges (need_eh_cleanup);
      cleanup_tree_cfg ();
      cleanup_tree_cfg ();
    }
    }
 
 
  BITMAP_FREE (need_eh_cleanup);
  BITMAP_FREE (need_eh_cleanup);
 
 
  /* Wipe out pointers to VALUE_HANDLEs.  In the not terribly distant
  /* Wipe out pointers to VALUE_HANDLEs.  In the not terribly distant
     future we will want them to be persistent though.  */
     future we will want them to be persistent though.  */
  for (i = 0; i < num_ssa_names; i++)
  for (i = 0; i < num_ssa_names; i++)
    {
    {
      tree name = ssa_name (i);
      tree name = ssa_name (i);
 
 
      if (!name)
      if (!name)
        continue;
        continue;
 
 
      if (SSA_NAME_VALUE (name)
      if (SSA_NAME_VALUE (name)
          && TREE_CODE (SSA_NAME_VALUE (name)) == VALUE_HANDLE)
          && TREE_CODE (SSA_NAME_VALUE (name)) == VALUE_HANDLE)
        SSA_NAME_VALUE (name) = NULL;
        SSA_NAME_VALUE (name) = NULL;
    }
    }
  if (!do_fre && current_loops)
  if (!do_fre && current_loops)
    {
    {
      loop_optimizer_finalize (current_loops);
      loop_optimizer_finalize (current_loops);
      current_loops = NULL;
      current_loops = NULL;
    }
    }
}
}
 
 
/* Main entry point to the SSA-PRE pass.  DO_FRE is true if the caller
/* Main entry point to the SSA-PRE pass.  DO_FRE is true if the caller
   only wants to do full redundancy elimination.  */
   only wants to do full redundancy elimination.  */
 
 
static void
static void
execute_pre (bool do_fre)
execute_pre (bool do_fre)
{
{
  init_pre (do_fre);
  init_pre (do_fre);
 
 
  if (!do_fre)
  if (!do_fre)
    insert_fake_stores ();
    insert_fake_stores ();
 
 
  /* Collect and value number expressions computed in each basic block.  */
  /* Collect and value number expressions computed in each basic block.  */
  compute_avail ();
  compute_avail ();
 
 
  if (dump_file && (dump_flags & TDF_DETAILS))
  if (dump_file && (dump_flags & TDF_DETAILS))
    {
    {
      basic_block bb;
      basic_block bb;
 
 
      FOR_ALL_BB (bb)
      FOR_ALL_BB (bb)
        {
        {
          print_value_set (dump_file, EXP_GEN (bb), "exp_gen", bb->index);
          print_value_set (dump_file, EXP_GEN (bb), "exp_gen", bb->index);
          bitmap_print_value_set (dump_file, TMP_GEN (bb), "tmp_gen",
          bitmap_print_value_set (dump_file, TMP_GEN (bb), "tmp_gen",
                                  bb->index);
                                  bb->index);
          bitmap_print_value_set (dump_file, AVAIL_OUT (bb), "avail_out",
          bitmap_print_value_set (dump_file, AVAIL_OUT (bb), "avail_out",
                                  bb->index);
                                  bb->index);
        }
        }
    }
    }
 
 
  /* Insert can get quite slow on an incredibly large number of basic
  /* Insert can get quite slow on an incredibly large number of basic
     blocks due to some quadratic behavior.  Until this behavior is
     blocks due to some quadratic behavior.  Until this behavior is
     fixed, don't run it when he have an incredibly large number of
     fixed, don't run it when he have an incredibly large number of
     bb's.  If we aren't going to run insert, there is no point in
     bb's.  If we aren't going to run insert, there is no point in
     computing ANTIC, either, even though it's plenty fast.  */
     computing ANTIC, either, even though it's plenty fast.  */
  if (!do_fre && n_basic_blocks < 4000)
  if (!do_fre && n_basic_blocks < 4000)
    {
    {
      vuse_names = XCNEWVEC (bitmap, num_ssa_names);
      vuse_names = XCNEWVEC (bitmap, num_ssa_names);
      compute_rvuse_and_antic_safe ();
      compute_rvuse_and_antic_safe ();
      compute_antic ();
      compute_antic ();
      insert ();
      insert ();
      free (vuse_names);
      free (vuse_names);
    }
    }
 
 
  /* Remove all the redundant expressions.  */
  /* Remove all the redundant expressions.  */
  eliminate ();
  eliminate ();
 
 
 
 
  if (dump_file && (dump_flags & TDF_STATS))
  if (dump_file && (dump_flags & TDF_STATS))
    {
    {
      fprintf (dump_file, "Insertions: %d\n", pre_stats.insertions);
      fprintf (dump_file, "Insertions: %d\n", pre_stats.insertions);
      fprintf (dump_file, "New PHIs: %d\n", pre_stats.phis);
      fprintf (dump_file, "New PHIs: %d\n", pre_stats.phis);
      fprintf (dump_file, "Eliminated: %d\n", pre_stats.eliminations);
      fprintf (dump_file, "Eliminated: %d\n", pre_stats.eliminations);
      fprintf (dump_file, "Constified: %d\n", pre_stats.constified);
      fprintf (dump_file, "Constified: %d\n", pre_stats.constified);
    }
    }
 
 
  bsi_commit_edge_inserts ();
  bsi_commit_edge_inserts ();
 
 
  if (!do_fre)
  if (!do_fre)
    {
    {
      remove_dead_inserted_code ();
      remove_dead_inserted_code ();
      realify_fake_stores ();
      realify_fake_stores ();
    }
    }
 
 
  fini_pre (do_fre);
  fini_pre (do_fre);
 
 
}
}
 
 
/* Gate and execute functions for PRE.  */
/* Gate and execute functions for PRE.  */
 
 
static unsigned int
static unsigned int
do_pre (void)
do_pre (void)
{
{
  execute_pre (false);
  execute_pre (false);
  return 0;
  return 0;
}
}
 
 
static bool
static bool
gate_pre (void)
gate_pre (void)
{
{
  return flag_tree_pre != 0;
  return flag_tree_pre != 0;
}
}
 
 
struct tree_opt_pass pass_pre =
struct tree_opt_pass pass_pre =
{
{
  "pre",                                /* name */
  "pre",                                /* name */
  gate_pre,                             /* gate */
  gate_pre,                             /* gate */
  do_pre,                               /* execute */
  do_pre,                               /* execute */
  NULL,                                 /* sub */
  NULL,                                 /* sub */
  NULL,                                 /* next */
  NULL,                                 /* next */
  0,                                     /* static_pass_number */
  0,                                     /* static_pass_number */
  TV_TREE_PRE,                          /* tv_id */
  TV_TREE_PRE,                          /* tv_id */
  PROP_no_crit_edges | PROP_cfg
  PROP_no_crit_edges | PROP_cfg
    | PROP_ssa | PROP_alias,            /* properties_required */
    | PROP_ssa | PROP_alias,            /* properties_required */
  0,                                     /* properties_provided */
  0,                                     /* properties_provided */
  0,                                     /* properties_destroyed */
  0,                                     /* properties_destroyed */
  0,                                     /* todo_flags_start */
  0,                                     /* todo_flags_start */
  TODO_update_ssa_only_virtuals | TODO_dump_func | TODO_ggc_collect
  TODO_update_ssa_only_virtuals | TODO_dump_func | TODO_ggc_collect
  | TODO_verify_ssa, /* todo_flags_finish */
  | TODO_verify_ssa, /* todo_flags_finish */
  0                                      /* letter */
  0                                      /* letter */
};
};
 
 
 
 
/* Gate and execute functions for FRE.  */
/* Gate and execute functions for FRE.  */
 
 
static unsigned int
static unsigned int
execute_fre (void)
execute_fre (void)
{
{
  execute_pre (true);
  execute_pre (true);
  return 0;
  return 0;
}
}
 
 
static bool
static bool
gate_fre (void)
gate_fre (void)
{
{
  return flag_tree_fre != 0;
  return flag_tree_fre != 0;
}
}
 
 
struct tree_opt_pass pass_fre =
struct tree_opt_pass pass_fre =
{
{
  "fre",                                /* name */
  "fre",                                /* name */
  gate_fre,                             /* gate */
  gate_fre,                             /* gate */
  execute_fre,                          /* execute */
  execute_fre,                          /* execute */
  NULL,                                 /* sub */
  NULL,                                 /* sub */
  NULL,                                 /* next */
  NULL,                                 /* next */
  0,                                     /* static_pass_number */
  0,                                     /* static_pass_number */
  TV_TREE_FRE,                          /* tv_id */
  TV_TREE_FRE,                          /* tv_id */
  PROP_cfg | PROP_ssa | PROP_alias,     /* properties_required */
  PROP_cfg | PROP_ssa | PROP_alias,     /* 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_ggc_collect | TODO_verify_ssa, /* todo_flags_finish */
  TODO_dump_func | TODO_ggc_collect | TODO_verify_ssa, /* todo_flags_finish */
  0                                      /* letter */
  0                                      /* letter */
};
};
 
 

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