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/* Register to Stack convert for GNU compiler.
/* Register to Stack convert for GNU compiler.
   Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
   2000, 2001, 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
   2000, 2001, 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
 
 
   This file is part of GCC.
   This file is part of GCC.
 
 
   GCC is free software; you can redistribute it and/or modify it
   GCC is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by
   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, but WITHOUT
   GCC is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
   License for more details.
   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/>.  */
 
 
/* This pass converts stack-like registers from the "flat register
/* This pass converts stack-like registers from the "flat register
   file" model that gcc uses, to a stack convention that the 387 uses.
   file" model that gcc uses, to a stack convention that the 387 uses.
 
 
   * The form of the input:
   * The form of the input:
 
 
   On input, the function consists of insn that have had their
   On input, the function consists of insn that have had their
   registers fully allocated to a set of "virtual" registers.  Note that
   registers fully allocated to a set of "virtual" registers.  Note that
   the word "virtual" is used differently here than elsewhere in gcc: for
   the word "virtual" is used differently here than elsewhere in gcc: for
   each virtual stack reg, there is a hard reg, but the mapping between
   each virtual stack reg, there is a hard reg, but the mapping between
   them is not known until this pass is run.  On output, hard register
   them is not known until this pass is run.  On output, hard register
   numbers have been substituted, and various pop and exchange insns have
   numbers have been substituted, and various pop and exchange insns have
   been emitted.  The hard register numbers and the virtual register
   been emitted.  The hard register numbers and the virtual register
   numbers completely overlap - before this pass, all stack register
   numbers completely overlap - before this pass, all stack register
   numbers are virtual, and afterward they are all hard.
   numbers are virtual, and afterward they are all hard.
 
 
   The virtual registers can be manipulated normally by gcc, and their
   The virtual registers can be manipulated normally by gcc, and their
   semantics are the same as for normal registers.  After the hard
   semantics are the same as for normal registers.  After the hard
   register numbers are substituted, the semantics of an insn containing
   register numbers are substituted, the semantics of an insn containing
   stack-like regs are not the same as for an insn with normal regs: for
   stack-like regs are not the same as for an insn with normal regs: for
   instance, it is not safe to delete an insn that appears to be a no-op
   instance, it is not safe to delete an insn that appears to be a no-op
   move.  In general, no insn containing hard regs should be changed
   move.  In general, no insn containing hard regs should be changed
   after this pass is done.
   after this pass is done.
 
 
   * The form of the output:
   * The form of the output:
 
 
   After this pass, hard register numbers represent the distance from
   After this pass, hard register numbers represent the distance from
   the current top of stack to the desired register.  A reference to
   the current top of stack to the desired register.  A reference to
   FIRST_STACK_REG references the top of stack, FIRST_STACK_REG + 1,
   FIRST_STACK_REG references the top of stack, FIRST_STACK_REG + 1,
   represents the register just below that, and so forth.  Also, REG_DEAD
   represents the register just below that, and so forth.  Also, REG_DEAD
   notes indicate whether or not a stack register should be popped.
   notes indicate whether or not a stack register should be popped.
 
 
   A "swap" insn looks like a parallel of two patterns, where each
   A "swap" insn looks like a parallel of two patterns, where each
   pattern is a SET: one sets A to B, the other B to A.
   pattern is a SET: one sets A to B, the other B to A.
 
 
   A "push" or "load" insn is a SET whose SET_DEST is FIRST_STACK_REG
   A "push" or "load" insn is a SET whose SET_DEST is FIRST_STACK_REG
   and whose SET_DEST is REG or MEM.  Any other SET_DEST, such as PLUS,
   and whose SET_DEST is REG or MEM.  Any other SET_DEST, such as PLUS,
   will replace the existing stack top, not push a new value.
   will replace the existing stack top, not push a new value.
 
 
   A store insn is a SET whose SET_DEST is FIRST_STACK_REG, and whose
   A store insn is a SET whose SET_DEST is FIRST_STACK_REG, and whose
   SET_SRC is REG or MEM.
   SET_SRC is REG or MEM.
 
 
   The case where the SET_SRC and SET_DEST are both FIRST_STACK_REG
   The case where the SET_SRC and SET_DEST are both FIRST_STACK_REG
   appears ambiguous.  As a special case, the presence of a REG_DEAD note
   appears ambiguous.  As a special case, the presence of a REG_DEAD note
   for FIRST_STACK_REG differentiates between a load insn and a pop.
   for FIRST_STACK_REG differentiates between a load insn and a pop.
 
 
   If a REG_DEAD is present, the insn represents a "pop" that discards
   If a REG_DEAD is present, the insn represents a "pop" that discards
   the top of the register stack.  If there is no REG_DEAD note, then the
   the top of the register stack.  If there is no REG_DEAD note, then the
   insn represents a "dup" or a push of the current top of stack onto the
   insn represents a "dup" or a push of the current top of stack onto the
   stack.
   stack.
 
 
   * Methodology:
   * Methodology:
 
 
   Existing REG_DEAD and REG_UNUSED notes for stack registers are
   Existing REG_DEAD and REG_UNUSED notes for stack registers are
   deleted and recreated from scratch.  REG_DEAD is never created for a
   deleted and recreated from scratch.  REG_DEAD is never created for a
   SET_DEST, only REG_UNUSED.
   SET_DEST, only REG_UNUSED.
 
 
   * asm_operands:
   * asm_operands:
 
 
   There are several rules on the usage of stack-like regs in
   There are several rules on the usage of stack-like regs in
   asm_operands insns.  These rules apply only to the operands that are
   asm_operands insns.  These rules apply only to the operands that are
   stack-like regs:
   stack-like regs:
 
 
   1. Given a set of input regs that die in an asm_operands, it is
   1. Given a set of input regs that die in an asm_operands, it is
      necessary to know which are implicitly popped by the asm, and
      necessary to know which are implicitly popped by the asm, and
      which must be explicitly popped by gcc.
      which must be explicitly popped by gcc.
 
 
        An input reg that is implicitly popped by the asm must be
        An input reg that is implicitly popped by the asm must be
        explicitly clobbered, unless it is constrained to match an
        explicitly clobbered, unless it is constrained to match an
        output operand.
        output operand.
 
 
   2. For any input reg that is implicitly popped by an asm, it is
   2. For any input reg that is implicitly popped by an asm, it is
      necessary to know how to adjust the stack to compensate for the pop.
      necessary to know how to adjust the stack to compensate for the pop.
      If any non-popped input is closer to the top of the reg-stack than
      If any non-popped input is closer to the top of the reg-stack than
      the implicitly popped reg, it would not be possible to know what the
      the implicitly popped reg, it would not be possible to know what the
      stack looked like - it's not clear how the rest of the stack "slides
      stack looked like - it's not clear how the rest of the stack "slides
      up".
      up".
 
 
        All implicitly popped input regs must be closer to the top of
        All implicitly popped input regs must be closer to the top of
        the reg-stack than any input that is not implicitly popped.
        the reg-stack than any input that is not implicitly popped.
 
 
   3. It is possible that if an input dies in an insn, reload might
   3. It is possible that if an input dies in an insn, reload might
      use the input reg for an output reload.  Consider this example:
      use the input reg for an output reload.  Consider this example:
 
 
                asm ("foo" : "=t" (a) : "f" (b));
                asm ("foo" : "=t" (a) : "f" (b));
 
 
      This asm says that input B is not popped by the asm, and that
      This asm says that input B is not popped by the asm, and that
      the asm pushes a result onto the reg-stack, i.e., the stack is one
      the asm pushes a result onto the reg-stack, i.e., the stack is one
      deeper after the asm than it was before.  But, it is possible that
      deeper after the asm than it was before.  But, it is possible that
      reload will think that it can use the same reg for both the input and
      reload will think that it can use the same reg for both the input and
      the output, if input B dies in this insn.
      the output, if input B dies in this insn.
 
 
        If any input operand uses the "f" constraint, all output reg
        If any input operand uses the "f" constraint, all output reg
        constraints must use the "&" earlyclobber.
        constraints must use the "&" earlyclobber.
 
 
      The asm above would be written as
      The asm above would be written as
 
 
                asm ("foo" : "=&t" (a) : "f" (b));
                asm ("foo" : "=&t" (a) : "f" (b));
 
 
   4. Some operands need to be in particular places on the stack.  All
   4. Some operands need to be in particular places on the stack.  All
      output operands fall in this category - there is no other way to
      output operands fall in this category - there is no other way to
      know which regs the outputs appear in unless the user indicates
      know which regs the outputs appear in unless the user indicates
      this in the constraints.
      this in the constraints.
 
 
        Output operands must specifically indicate which reg an output
        Output operands must specifically indicate which reg an output
        appears in after an asm.  "=f" is not allowed: the operand
        appears in after an asm.  "=f" is not allowed: the operand
        constraints must select a class with a single reg.
        constraints must select a class with a single reg.
 
 
   5. Output operands may not be "inserted" between existing stack regs.
   5. Output operands may not be "inserted" between existing stack regs.
      Since no 387 opcode uses a read/write operand, all output operands
      Since no 387 opcode uses a read/write operand, all output operands
      are dead before the asm_operands, and are pushed by the asm_operands.
      are dead before the asm_operands, and are pushed by the asm_operands.
      It makes no sense to push anywhere but the top of the reg-stack.
      It makes no sense to push anywhere but the top of the reg-stack.
 
 
        Output operands must start at the top of the reg-stack: output
        Output operands must start at the top of the reg-stack: output
        operands may not "skip" a reg.
        operands may not "skip" a reg.
 
 
   6. Some asm statements may need extra stack space for internal
   6. Some asm statements may need extra stack space for internal
      calculations.  This can be guaranteed by clobbering stack registers
      calculations.  This can be guaranteed by clobbering stack registers
      unrelated to the inputs and outputs.
      unrelated to the inputs and outputs.
 
 
   Here are a couple of reasonable asms to want to write.  This asm
   Here are a couple of reasonable asms to want to write.  This asm
   takes one input, which is internally popped, and produces two outputs.
   takes one input, which is internally popped, and produces two outputs.
 
 
        asm ("fsincos" : "=t" (cos), "=u" (sin) : "0" (inp));
        asm ("fsincos" : "=t" (cos), "=u" (sin) : "0" (inp));
 
 
   This asm takes two inputs, which are popped by the fyl2xp1 opcode,
   This asm takes two inputs, which are popped by the fyl2xp1 opcode,
   and replaces them with one output.  The user must code the "st(1)"
   and replaces them with one output.  The user must code the "st(1)"
   clobber for reg-stack.c to know that fyl2xp1 pops both inputs.
   clobber for reg-stack.c to know that fyl2xp1 pops both inputs.
 
 
        asm ("fyl2xp1" : "=t" (result) : "0" (x), "u" (y) : "st(1)");
        asm ("fyl2xp1" : "=t" (result) : "0" (x), "u" (y) : "st(1)");
 
 
*/
*/


#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 "tree.h"
#include "tree.h"
#include "rtl.h"
#include "rtl.h"
#include "tm_p.h"
#include "tm_p.h"
#include "function.h"
#include "function.h"
#include "insn-config.h"
#include "insn-config.h"
#include "regs.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "hard-reg-set.h"
#include "flags.h"
#include "flags.h"
#include "toplev.h"
#include "toplev.h"
#include "recog.h"
#include "recog.h"
#include "output.h"
#include "output.h"
#include "basic-block.h"
#include "basic-block.h"
#include "varray.h"
#include "varray.h"
#include "reload.h"
#include "reload.h"
#include "ggc.h"
#include "ggc.h"
#include "timevar.h"
#include "timevar.h"
#include "tree-pass.h"
#include "tree-pass.h"
#include "target.h"
#include "target.h"
#include "vecprim.h"
#include "vecprim.h"
 
 
#ifdef STACK_REGS
#ifdef STACK_REGS
 
 
/* We use this array to cache info about insns, because otherwise we
/* We use this array to cache info about insns, because otherwise we
   spend too much time in stack_regs_mentioned_p.
   spend too much time in stack_regs_mentioned_p.
 
 
   Indexed by insn UIDs.  A value of zero is uninitialized, one indicates
   Indexed by insn UIDs.  A value of zero is uninitialized, one indicates
   the insn uses stack registers, two indicates the insn does not use
   the insn uses stack registers, two indicates the insn does not use
   stack registers.  */
   stack registers.  */
static VEC(char,heap) *stack_regs_mentioned_data;
static VEC(char,heap) *stack_regs_mentioned_data;
 
 
#define REG_STACK_SIZE (LAST_STACK_REG - FIRST_STACK_REG + 1)
#define REG_STACK_SIZE (LAST_STACK_REG - FIRST_STACK_REG + 1)
 
 
int regstack_completed = 0;
int regstack_completed = 0;
 
 
/* This is the basic stack record.  TOP is an index into REG[] such
/* This is the basic stack record.  TOP is an index into REG[] such
   that REG[TOP] is the top of stack.  If TOP is -1 the stack is empty.
   that REG[TOP] is the top of stack.  If TOP is -1 the stack is empty.
 
 
   If TOP is -2, REG[] is not yet initialized.  Stack initialization
   If TOP is -2, REG[] is not yet initialized.  Stack initialization
   consists of placing each live reg in array `reg' and setting `top'
   consists of placing each live reg in array `reg' and setting `top'
   appropriately.
   appropriately.
 
 
   REG_SET indicates which registers are live.  */
   REG_SET indicates which registers are live.  */
 
 
typedef struct stack_def
typedef struct stack_def
{
{
  int top;                      /* index to top stack element */
  int top;                      /* index to top stack element */
  HARD_REG_SET reg_set;         /* set of live registers */
  HARD_REG_SET reg_set;         /* set of live registers */
  unsigned char reg[REG_STACK_SIZE];/* register - stack mapping */
  unsigned char reg[REG_STACK_SIZE];/* register - stack mapping */
} *stack;
} *stack;
 
 
/* This is used to carry information about basic blocks.  It is
/* This is used to carry information about basic blocks.  It is
   attached to the AUX field of the standard CFG block.  */
   attached to the AUX field of the standard CFG block.  */
 
 
typedef struct block_info_def
typedef struct block_info_def
{
{
  struct stack_def stack_in;    /* Input stack configuration.  */
  struct stack_def stack_in;    /* Input stack configuration.  */
  struct stack_def stack_out;   /* Output stack configuration.  */
  struct stack_def stack_out;   /* Output stack configuration.  */
  HARD_REG_SET out_reg_set;     /* Stack regs live on output.  */
  HARD_REG_SET out_reg_set;     /* Stack regs live on output.  */
  int done;                     /* True if block already converted.  */
  int done;                     /* True if block already converted.  */
  int predecessors;             /* Number of predecessors that need
  int predecessors;             /* Number of predecessors that need
                                   to be visited.  */
                                   to be visited.  */
} *block_info;
} *block_info;
 
 
#define BLOCK_INFO(B)   ((block_info) (B)->aux)
#define BLOCK_INFO(B)   ((block_info) (B)->aux)
 
 
/* Passed to change_stack to indicate where to emit insns.  */
/* Passed to change_stack to indicate where to emit insns.  */
enum emit_where
enum emit_where
{
{
  EMIT_AFTER,
  EMIT_AFTER,
  EMIT_BEFORE
  EMIT_BEFORE
};
};
 
 
/* The block we're currently working on.  */
/* The block we're currently working on.  */
static basic_block current_block;
static basic_block current_block;
 
 
/* In the current_block, whether we're processing the first register
/* In the current_block, whether we're processing the first register
   stack or call instruction, i.e. the regstack is currently the
   stack or call instruction, i.e. the regstack is currently the
   same as BLOCK_INFO(current_block)->stack_in.  */
   same as BLOCK_INFO(current_block)->stack_in.  */
static bool starting_stack_p;
static bool starting_stack_p;
 
 
/* This is the register file for all register after conversion.  */
/* This is the register file for all register after conversion.  */
static rtx
static rtx
  FP_mode_reg[LAST_STACK_REG+1-FIRST_STACK_REG][(int) MAX_MACHINE_MODE];
  FP_mode_reg[LAST_STACK_REG+1-FIRST_STACK_REG][(int) MAX_MACHINE_MODE];
 
 
#define FP_MODE_REG(regno,mode) \
#define FP_MODE_REG(regno,mode) \
  (FP_mode_reg[(regno)-FIRST_STACK_REG][(int) (mode)])
  (FP_mode_reg[(regno)-FIRST_STACK_REG][(int) (mode)])
 
 
/* Used to initialize uninitialized registers.  */
/* Used to initialize uninitialized registers.  */
static rtx not_a_num;
static rtx not_a_num;
 
 
/* Forward declarations */
/* Forward declarations */
 
 
static int stack_regs_mentioned_p (rtx pat);
static int stack_regs_mentioned_p (rtx pat);
static void pop_stack (stack, int);
static void pop_stack (stack, int);
static rtx *get_true_reg (rtx *);
static rtx *get_true_reg (rtx *);
 
 
static int check_asm_stack_operands (rtx);
static int check_asm_stack_operands (rtx);
static int get_asm_operand_n_inputs (rtx);
static int get_asm_operand_n_inputs (rtx);
static rtx stack_result (tree);
static rtx stack_result (tree);
static void replace_reg (rtx *, int);
static void replace_reg (rtx *, int);
static void remove_regno_note (rtx, enum reg_note, unsigned int);
static void remove_regno_note (rtx, enum reg_note, unsigned int);
static int get_hard_regnum (stack, rtx);
static int get_hard_regnum (stack, rtx);
static rtx emit_pop_insn (rtx, stack, rtx, enum emit_where);
static rtx emit_pop_insn (rtx, stack, rtx, enum emit_where);
static void swap_to_top(rtx, stack, rtx, rtx);
static void swap_to_top(rtx, stack, rtx, rtx);
static bool move_for_stack_reg (rtx, stack, rtx);
static bool move_for_stack_reg (rtx, stack, rtx);
static bool move_nan_for_stack_reg (rtx, stack, rtx);
static bool move_nan_for_stack_reg (rtx, stack, rtx);
static int swap_rtx_condition_1 (rtx);
static int swap_rtx_condition_1 (rtx);
static int swap_rtx_condition (rtx);
static int swap_rtx_condition (rtx);
static void compare_for_stack_reg (rtx, stack, rtx);
static void compare_for_stack_reg (rtx, stack, rtx);
static bool subst_stack_regs_pat (rtx, stack, rtx);
static bool subst_stack_regs_pat (rtx, stack, rtx);
static void subst_asm_stack_regs (rtx, stack);
static void subst_asm_stack_regs (rtx, stack);
static bool subst_stack_regs (rtx, stack);
static bool subst_stack_regs (rtx, stack);
static void change_stack (rtx, stack, stack, enum emit_where);
static void change_stack (rtx, stack, stack, enum emit_where);
static void print_stack (FILE *, stack);
static void print_stack (FILE *, stack);
static rtx next_flags_user (rtx);
static rtx next_flags_user (rtx);


/* Return nonzero if any stack register is mentioned somewhere within PAT.  */
/* Return nonzero if any stack register is mentioned somewhere within PAT.  */
 
 
static int
static int
stack_regs_mentioned_p (rtx pat)
stack_regs_mentioned_p (rtx pat)
{
{
  const char *fmt;
  const char *fmt;
  int i;
  int i;
 
 
  if (STACK_REG_P (pat))
  if (STACK_REG_P (pat))
    return 1;
    return 1;
 
 
  fmt = GET_RTX_FORMAT (GET_CODE (pat));
  fmt = GET_RTX_FORMAT (GET_CODE (pat));
  for (i = GET_RTX_LENGTH (GET_CODE (pat)) - 1; i >= 0; i--)
  for (i = GET_RTX_LENGTH (GET_CODE (pat)) - 1; i >= 0; i--)
    {
    {
      if (fmt[i] == 'E')
      if (fmt[i] == 'E')
        {
        {
          int j;
          int j;
 
 
          for (j = XVECLEN (pat, i) - 1; j >= 0; j--)
          for (j = XVECLEN (pat, i) - 1; j >= 0; j--)
            if (stack_regs_mentioned_p (XVECEXP (pat, i, j)))
            if (stack_regs_mentioned_p (XVECEXP (pat, i, j)))
              return 1;
              return 1;
        }
        }
      else if (fmt[i] == 'e' && stack_regs_mentioned_p (XEXP (pat, i)))
      else if (fmt[i] == 'e' && stack_regs_mentioned_p (XEXP (pat, i)))
        return 1;
        return 1;
    }
    }
 
 
  return 0;
  return 0;
}
}
 
 
/* Return nonzero if INSN mentions stacked registers, else return zero.  */
/* Return nonzero if INSN mentions stacked registers, else return zero.  */
 
 
int
int
stack_regs_mentioned (rtx insn)
stack_regs_mentioned (rtx insn)
{
{
  unsigned int uid, max;
  unsigned int uid, max;
  int test;
  int test;
 
 
  if (! INSN_P (insn) || !stack_regs_mentioned_data)
  if (! INSN_P (insn) || !stack_regs_mentioned_data)
    return 0;
    return 0;
 
 
  uid = INSN_UID (insn);
  uid = INSN_UID (insn);
  max = VEC_length (char, stack_regs_mentioned_data);
  max = VEC_length (char, stack_regs_mentioned_data);
  if (uid >= max)
  if (uid >= max)
    {
    {
      char *p;
      char *p;
      unsigned int old_max = max;
      unsigned int old_max = max;
 
 
      /* Allocate some extra size to avoid too many reallocs, but
      /* Allocate some extra size to avoid too many reallocs, but
         do not grow too quickly.  */
         do not grow too quickly.  */
      max = uid + uid / 20 + 1;
      max = uid + uid / 20 + 1;
      VEC_safe_grow (char, heap, stack_regs_mentioned_data, max);
      VEC_safe_grow (char, heap, stack_regs_mentioned_data, max);
      p = VEC_address (char, stack_regs_mentioned_data);
      p = VEC_address (char, stack_regs_mentioned_data);
      memset (&p[old_max], 0,
      memset (&p[old_max], 0,
              sizeof (char) * (max - old_max));
              sizeof (char) * (max - old_max));
    }
    }
 
 
  test = VEC_index (char, stack_regs_mentioned_data, uid);
  test = VEC_index (char, stack_regs_mentioned_data, uid);
  if (test == 0)
  if (test == 0)
    {
    {
      /* This insn has yet to be examined.  Do so now.  */
      /* This insn has yet to be examined.  Do so now.  */
      test = stack_regs_mentioned_p (PATTERN (insn)) ? 1 : 2;
      test = stack_regs_mentioned_p (PATTERN (insn)) ? 1 : 2;
      VEC_replace (char, stack_regs_mentioned_data, uid, test);
      VEC_replace (char, stack_regs_mentioned_data, uid, test);
    }
    }
 
 
  return test == 1;
  return test == 1;
}
}


static rtx ix86_flags_rtx;
static rtx ix86_flags_rtx;
 
 
static rtx
static rtx
next_flags_user (rtx insn)
next_flags_user (rtx insn)
{
{
  /* Search forward looking for the first use of this value.
  /* Search forward looking for the first use of this value.
     Stop at block boundaries.  */
     Stop at block boundaries.  */
 
 
  while (insn != BB_END (current_block))
  while (insn != BB_END (current_block))
    {
    {
      insn = NEXT_INSN (insn);
      insn = NEXT_INSN (insn);
 
 
      if (INSN_P (insn) && reg_mentioned_p (ix86_flags_rtx, PATTERN (insn)))
      if (INSN_P (insn) && reg_mentioned_p (ix86_flags_rtx, PATTERN (insn)))
        return insn;
        return insn;
 
 
      if (CALL_P (insn))
      if (CALL_P (insn))
        return NULL_RTX;
        return NULL_RTX;
    }
    }
  return NULL_RTX;
  return NULL_RTX;
}
}


/* Reorganize the stack into ascending numbers, before this insn.  */
/* Reorganize the stack into ascending numbers, before this insn.  */
 
 
static void
static void
straighten_stack (rtx insn, stack regstack)
straighten_stack (rtx insn, stack regstack)
{
{
  struct stack_def temp_stack;
  struct stack_def temp_stack;
  int top;
  int top;
 
 
  /* If there is only a single register on the stack, then the stack is
  /* If there is only a single register on the stack, then the stack is
     already in increasing order and no reorganization is needed.
     already in increasing order and no reorganization is needed.
 
 
     Similarly if the stack is empty.  */
     Similarly if the stack is empty.  */
  if (regstack->top <= 0)
  if (regstack->top <= 0)
    return;
    return;
 
 
  COPY_HARD_REG_SET (temp_stack.reg_set, regstack->reg_set);
  COPY_HARD_REG_SET (temp_stack.reg_set, regstack->reg_set);
 
 
  for (top = temp_stack.top = regstack->top; top >= 0; top--)
  for (top = temp_stack.top = regstack->top; top >= 0; top--)
    temp_stack.reg[top] = FIRST_STACK_REG + temp_stack.top - top;
    temp_stack.reg[top] = FIRST_STACK_REG + temp_stack.top - top;
 
 
  change_stack (insn, regstack, &temp_stack, EMIT_BEFORE);
  change_stack (insn, regstack, &temp_stack, EMIT_BEFORE);
}
}
 
 
/* Pop a register from the stack.  */
/* Pop a register from the stack.  */
 
 
static void
static void
pop_stack (stack regstack, int regno)
pop_stack (stack regstack, int regno)
{
{
  int top = regstack->top;
  int top = regstack->top;
 
 
  CLEAR_HARD_REG_BIT (regstack->reg_set, regno);
  CLEAR_HARD_REG_BIT (regstack->reg_set, regno);
  regstack->top--;
  regstack->top--;
  /* If regno was not at the top of stack then adjust stack.  */
  /* If regno was not at the top of stack then adjust stack.  */
  if (regstack->reg [top] != regno)
  if (regstack->reg [top] != regno)
    {
    {
      int i;
      int i;
      for (i = regstack->top; i >= 0; i--)
      for (i = regstack->top; i >= 0; i--)
        if (regstack->reg [i] == regno)
        if (regstack->reg [i] == regno)
          {
          {
            int j;
            int j;
            for (j = i; j < top; j++)
            for (j = i; j < top; j++)
              regstack->reg [j] = regstack->reg [j + 1];
              regstack->reg [j] = regstack->reg [j + 1];
            break;
            break;
          }
          }
    }
    }
}
}


/* Return a pointer to the REG expression within PAT.  If PAT is not a
/* Return a pointer to the REG expression within PAT.  If PAT is not a
   REG, possible enclosed by a conversion rtx, return the inner part of
   REG, possible enclosed by a conversion rtx, return the inner part of
   PAT that stopped the search.  */
   PAT that stopped the search.  */
 
 
static rtx *
static rtx *
get_true_reg (rtx *pat)
get_true_reg (rtx *pat)
{
{
  for (;;)
  for (;;)
    switch (GET_CODE (*pat))
    switch (GET_CODE (*pat))
      {
      {
      case SUBREG:
      case SUBREG:
        /* Eliminate FP subregister accesses in favor of the
        /* Eliminate FP subregister accesses in favor of the
           actual FP register in use.  */
           actual FP register in use.  */
        {
        {
          rtx subreg;
          rtx subreg;
          if (FP_REG_P (subreg = SUBREG_REG (*pat)))
          if (FP_REG_P (subreg = SUBREG_REG (*pat)))
            {
            {
              int regno_off = subreg_regno_offset (REGNO (subreg),
              int regno_off = subreg_regno_offset (REGNO (subreg),
                                                   GET_MODE (subreg),
                                                   GET_MODE (subreg),
                                                   SUBREG_BYTE (*pat),
                                                   SUBREG_BYTE (*pat),
                                                   GET_MODE (*pat));
                                                   GET_MODE (*pat));
              *pat = FP_MODE_REG (REGNO (subreg) + regno_off,
              *pat = FP_MODE_REG (REGNO (subreg) + regno_off,
                                  GET_MODE (subreg));
                                  GET_MODE (subreg));
            default:
            default:
              return pat;
              return pat;
            }
            }
        }
        }
      case FLOAT:
      case FLOAT:
      case FIX:
      case FIX:
      case FLOAT_EXTEND:
      case FLOAT_EXTEND:
        pat = & XEXP (*pat, 0);
        pat = & XEXP (*pat, 0);
        break;
        break;
 
 
      case FLOAT_TRUNCATE:
      case FLOAT_TRUNCATE:
        if (!flag_unsafe_math_optimizations)
        if (!flag_unsafe_math_optimizations)
          return pat;
          return pat;
        pat = & XEXP (*pat, 0);
        pat = & XEXP (*pat, 0);
        break;
        break;
      }
      }
}
}


/* Set if we find any malformed asms in a block.  */
/* Set if we find any malformed asms in a block.  */
static bool any_malformed_asm;
static bool any_malformed_asm;
 
 
/* There are many rules that an asm statement for stack-like regs must
/* There are many rules that an asm statement for stack-like regs must
   follow.  Those rules are explained at the top of this file: the rule
   follow.  Those rules are explained at the top of this file: the rule
   numbers below refer to that explanation.  */
   numbers below refer to that explanation.  */
 
 
static int
static int
check_asm_stack_operands (rtx insn)
check_asm_stack_operands (rtx insn)
{
{
  int i;
  int i;
  int n_clobbers;
  int n_clobbers;
  int malformed_asm = 0;
  int malformed_asm = 0;
  rtx body = PATTERN (insn);
  rtx body = PATTERN (insn);
 
 
  char reg_used_as_output[FIRST_PSEUDO_REGISTER];
  char reg_used_as_output[FIRST_PSEUDO_REGISTER];
  char implicitly_dies[FIRST_PSEUDO_REGISTER];
  char implicitly_dies[FIRST_PSEUDO_REGISTER];
  int alt;
  int alt;
 
 
  rtx *clobber_reg = 0;
  rtx *clobber_reg = 0;
  int n_inputs, n_outputs;
  int n_inputs, n_outputs;
 
 
  /* Find out what the constraints require.  If no constraint
  /* Find out what the constraints require.  If no constraint
     alternative matches, this asm is malformed.  */
     alternative matches, this asm is malformed.  */
  extract_insn (insn);
  extract_insn (insn);
  constrain_operands (1);
  constrain_operands (1);
  alt = which_alternative;
  alt = which_alternative;
 
 
  preprocess_constraints ();
  preprocess_constraints ();
 
 
  n_inputs = get_asm_operand_n_inputs (body);
  n_inputs = get_asm_operand_n_inputs (body);
  n_outputs = recog_data.n_operands - n_inputs;
  n_outputs = recog_data.n_operands - n_inputs;
 
 
  if (alt < 0)
  if (alt < 0)
    {
    {
      malformed_asm = 1;
      malformed_asm = 1;
      /* Avoid further trouble with this insn.  */
      /* Avoid further trouble with this insn.  */
      PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
      PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
      return 0;
      return 0;
    }
    }
 
 
  /* Strip SUBREGs here to make the following code simpler.  */
  /* Strip SUBREGs here to make the following code simpler.  */
  for (i = 0; i < recog_data.n_operands; i++)
  for (i = 0; i < recog_data.n_operands; i++)
    if (GET_CODE (recog_data.operand[i]) == SUBREG
    if (GET_CODE (recog_data.operand[i]) == SUBREG
        && REG_P (SUBREG_REG (recog_data.operand[i])))
        && REG_P (SUBREG_REG (recog_data.operand[i])))
      recog_data.operand[i] = SUBREG_REG (recog_data.operand[i]);
      recog_data.operand[i] = SUBREG_REG (recog_data.operand[i]);
 
 
  /* Set up CLOBBER_REG.  */
  /* Set up CLOBBER_REG.  */
 
 
  n_clobbers = 0;
  n_clobbers = 0;
 
 
  if (GET_CODE (body) == PARALLEL)
  if (GET_CODE (body) == PARALLEL)
    {
    {
      clobber_reg = alloca (XVECLEN (body, 0) * sizeof (rtx));
      clobber_reg = alloca (XVECLEN (body, 0) * sizeof (rtx));
 
 
      for (i = 0; i < XVECLEN (body, 0); i++)
      for (i = 0; i < XVECLEN (body, 0); i++)
        if (GET_CODE (XVECEXP (body, 0, i)) == CLOBBER)
        if (GET_CODE (XVECEXP (body, 0, i)) == CLOBBER)
          {
          {
            rtx clobber = XVECEXP (body, 0, i);
            rtx clobber = XVECEXP (body, 0, i);
            rtx reg = XEXP (clobber, 0);
            rtx reg = XEXP (clobber, 0);
 
 
            if (GET_CODE (reg) == SUBREG && REG_P (SUBREG_REG (reg)))
            if (GET_CODE (reg) == SUBREG && REG_P (SUBREG_REG (reg)))
              reg = SUBREG_REG (reg);
              reg = SUBREG_REG (reg);
 
 
            if (STACK_REG_P (reg))
            if (STACK_REG_P (reg))
              {
              {
                clobber_reg[n_clobbers] = reg;
                clobber_reg[n_clobbers] = reg;
                n_clobbers++;
                n_clobbers++;
              }
              }
          }
          }
    }
    }
 
 
  /* Enforce rule #4: Output operands must specifically indicate which
  /* Enforce rule #4: Output operands must specifically indicate which
     reg an output appears in after an asm.  "=f" is not allowed: the
     reg an output appears in after an asm.  "=f" is not allowed: the
     operand constraints must select a class with a single reg.
     operand constraints must select a class with a single reg.
 
 
     Also enforce rule #5: Output operands must start at the top of
     Also enforce rule #5: Output operands must start at the top of
     the reg-stack: output operands may not "skip" a reg.  */
     the reg-stack: output operands may not "skip" a reg.  */
 
 
  memset (reg_used_as_output, 0, sizeof (reg_used_as_output));
  memset (reg_used_as_output, 0, sizeof (reg_used_as_output));
  for (i = 0; i < n_outputs; i++)
  for (i = 0; i < n_outputs; i++)
    if (STACK_REG_P (recog_data.operand[i]))
    if (STACK_REG_P (recog_data.operand[i]))
      {
      {
        if (reg_class_size[(int) recog_op_alt[i][alt].cl] != 1)
        if (reg_class_size[(int) recog_op_alt[i][alt].cl] != 1)
          {
          {
            error_for_asm (insn, "output constraint %d must specify a single register", i);
            error_for_asm (insn, "output constraint %d must specify a single register", i);
            malformed_asm = 1;
            malformed_asm = 1;
          }
          }
        else
        else
          {
          {
            int j;
            int j;
 
 
            for (j = 0; j < n_clobbers; j++)
            for (j = 0; j < n_clobbers; j++)
              if (REGNO (recog_data.operand[i]) == REGNO (clobber_reg[j]))
              if (REGNO (recog_data.operand[i]) == REGNO (clobber_reg[j]))
                {
                {
                  error_for_asm (insn, "output constraint %d cannot be specified together with \"%s\" clobber",
                  error_for_asm (insn, "output constraint %d cannot be specified together with \"%s\" clobber",
                                 i, reg_names [REGNO (clobber_reg[j])]);
                                 i, reg_names [REGNO (clobber_reg[j])]);
                  malformed_asm = 1;
                  malformed_asm = 1;
                  break;
                  break;
                }
                }
            if (j == n_clobbers)
            if (j == n_clobbers)
              reg_used_as_output[REGNO (recog_data.operand[i])] = 1;
              reg_used_as_output[REGNO (recog_data.operand[i])] = 1;
          }
          }
      }
      }
 
 
 
 
  /* Search for first non-popped reg.  */
  /* Search for first non-popped reg.  */
  for (i = FIRST_STACK_REG; i < LAST_STACK_REG + 1; i++)
  for (i = FIRST_STACK_REG; i < LAST_STACK_REG + 1; i++)
    if (! reg_used_as_output[i])
    if (! reg_used_as_output[i])
      break;
      break;
 
 
  /* If there are any other popped regs, that's an error.  */
  /* If there are any other popped regs, that's an error.  */
  for (; i < LAST_STACK_REG + 1; i++)
  for (; i < LAST_STACK_REG + 1; i++)
    if (reg_used_as_output[i])
    if (reg_used_as_output[i])
      break;
      break;
 
 
  if (i != LAST_STACK_REG + 1)
  if (i != LAST_STACK_REG + 1)
    {
    {
      error_for_asm (insn, "output regs must be grouped at top of stack");
      error_for_asm (insn, "output regs must be grouped at top of stack");
      malformed_asm = 1;
      malformed_asm = 1;
    }
    }
 
 
  /* Enforce rule #2: All implicitly popped input regs must be closer
  /* Enforce rule #2: All implicitly popped input regs must be closer
     to the top of the reg-stack than any input that is not implicitly
     to the top of the reg-stack than any input that is not implicitly
     popped.  */
     popped.  */
 
 
  memset (implicitly_dies, 0, sizeof (implicitly_dies));
  memset (implicitly_dies, 0, sizeof (implicitly_dies));
  for (i = n_outputs; i < n_outputs + n_inputs; i++)
  for (i = n_outputs; i < n_outputs + n_inputs; i++)
    if (STACK_REG_P (recog_data.operand[i]))
    if (STACK_REG_P (recog_data.operand[i]))
      {
      {
        /* An input reg is implicitly popped if it is tied to an
        /* An input reg is implicitly popped if it is tied to an
           output, or if there is a CLOBBER for it.  */
           output, or if there is a CLOBBER for it.  */
        int j;
        int j;
 
 
        for (j = 0; j < n_clobbers; j++)
        for (j = 0; j < n_clobbers; j++)
          if (operands_match_p (clobber_reg[j], recog_data.operand[i]))
          if (operands_match_p (clobber_reg[j], recog_data.operand[i]))
            break;
            break;
 
 
        if (j < n_clobbers || recog_op_alt[i][alt].matches >= 0)
        if (j < n_clobbers || recog_op_alt[i][alt].matches >= 0)
          implicitly_dies[REGNO (recog_data.operand[i])] = 1;
          implicitly_dies[REGNO (recog_data.operand[i])] = 1;
      }
      }
 
 
  /* Search for first non-popped reg.  */
  /* Search for first non-popped reg.  */
  for (i = FIRST_STACK_REG; i < LAST_STACK_REG + 1; i++)
  for (i = FIRST_STACK_REG; i < LAST_STACK_REG + 1; i++)
    if (! implicitly_dies[i])
    if (! implicitly_dies[i])
      break;
      break;
 
 
  /* If there are any other popped regs, that's an error.  */
  /* If there are any other popped regs, that's an error.  */
  for (; i < LAST_STACK_REG + 1; i++)
  for (; i < LAST_STACK_REG + 1; i++)
    if (implicitly_dies[i])
    if (implicitly_dies[i])
      break;
      break;
 
 
  if (i != LAST_STACK_REG + 1)
  if (i != LAST_STACK_REG + 1)
    {
    {
      error_for_asm (insn,
      error_for_asm (insn,
                     "implicitly popped regs must be grouped at top of stack");
                     "implicitly popped regs must be grouped at top of stack");
      malformed_asm = 1;
      malformed_asm = 1;
    }
    }
 
 
  /* Enforce rule #3: If any input operand uses the "f" constraint, all
  /* Enforce rule #3: If any input operand uses the "f" constraint, all
     output constraints must use the "&" earlyclobber.
     output constraints must use the "&" earlyclobber.
 
 
     ??? Detect this more deterministically by having constrain_asm_operands
     ??? Detect this more deterministically by having constrain_asm_operands
     record any earlyclobber.  */
     record any earlyclobber.  */
 
 
  for (i = n_outputs; i < n_outputs + n_inputs; i++)
  for (i = n_outputs; i < n_outputs + n_inputs; i++)
    if (recog_op_alt[i][alt].matches == -1)
    if (recog_op_alt[i][alt].matches == -1)
      {
      {
        int j;
        int j;
 
 
        for (j = 0; j < n_outputs; j++)
        for (j = 0; j < n_outputs; j++)
          if (operands_match_p (recog_data.operand[j], recog_data.operand[i]))
          if (operands_match_p (recog_data.operand[j], recog_data.operand[i]))
            {
            {
              error_for_asm (insn,
              error_for_asm (insn,
                             "output operand %d must use %<&%> constraint", j);
                             "output operand %d must use %<&%> constraint", j);
              malformed_asm = 1;
              malformed_asm = 1;
            }
            }
      }
      }
 
 
  if (malformed_asm)
  if (malformed_asm)
    {
    {
      /* Avoid further trouble with this insn.  */
      /* Avoid further trouble with this insn.  */
      PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
      PATTERN (insn) = gen_rtx_USE (VOIDmode, const0_rtx);
      any_malformed_asm = true;
      any_malformed_asm = true;
      return 0;
      return 0;
    }
    }
 
 
  return 1;
  return 1;
}
}


/* Calculate the number of inputs and outputs in BODY, an
/* Calculate the number of inputs and outputs in BODY, an
   asm_operands.  N_OPERANDS is the total number of operands, and
   asm_operands.  N_OPERANDS is the total number of operands, and
   N_INPUTS and N_OUTPUTS are pointers to ints into which the results are
   N_INPUTS and N_OUTPUTS are pointers to ints into which the results are
   placed.  */
   placed.  */
 
 
static int
static int
get_asm_operand_n_inputs (rtx body)
get_asm_operand_n_inputs (rtx body)
{
{
  switch (GET_CODE (body))
  switch (GET_CODE (body))
    {
    {
    case SET:
    case SET:
      gcc_assert (GET_CODE (SET_SRC (body)) == ASM_OPERANDS);
      gcc_assert (GET_CODE (SET_SRC (body)) == ASM_OPERANDS);
      return ASM_OPERANDS_INPUT_LENGTH (SET_SRC (body));
      return ASM_OPERANDS_INPUT_LENGTH (SET_SRC (body));
 
 
    case ASM_OPERANDS:
    case ASM_OPERANDS:
      return ASM_OPERANDS_INPUT_LENGTH (body);
      return ASM_OPERANDS_INPUT_LENGTH (body);
 
 
    case PARALLEL:
    case PARALLEL:
      return get_asm_operand_n_inputs (XVECEXP (body, 0, 0));
      return get_asm_operand_n_inputs (XVECEXP (body, 0, 0));
 
 
    default:
    default:
      gcc_unreachable ();
      gcc_unreachable ();
    }
    }
}
}
 
 
/* If current function returns its result in an fp stack register,
/* If current function returns its result in an fp stack register,
   return the REG.  Otherwise, return 0.  */
   return the REG.  Otherwise, return 0.  */
 
 
static rtx
static rtx
stack_result (tree decl)
stack_result (tree decl)
{
{
  rtx result;
  rtx result;
 
 
  /* If the value is supposed to be returned in memory, then clearly
  /* If the value is supposed to be returned in memory, then clearly
     it is not returned in a stack register.  */
     it is not returned in a stack register.  */
  if (aggregate_value_p (DECL_RESULT (decl), decl))
  if (aggregate_value_p (DECL_RESULT (decl), decl))
    return 0;
    return 0;
 
 
  result = DECL_RTL_IF_SET (DECL_RESULT (decl));
  result = DECL_RTL_IF_SET (DECL_RESULT (decl));
  if (result != 0)
  if (result != 0)
    result = targetm.calls.function_value (TREE_TYPE (DECL_RESULT (decl)),
    result = targetm.calls.function_value (TREE_TYPE (DECL_RESULT (decl)),
                                           decl, true);
                                           decl, true);
 
 
  return result != 0 && STACK_REG_P (result) ? result : 0;
  return result != 0 && STACK_REG_P (result) ? result : 0;
}
}


 
 
/*
/*
 * This section deals with stack register substitution, and forms the second
 * This section deals with stack register substitution, and forms the second
 * pass over the RTL.
 * pass over the RTL.
 */
 */
 
 
/* Replace REG, which is a pointer to a stack reg RTX, with an RTX for
/* Replace REG, which is a pointer to a stack reg RTX, with an RTX for
   the desired hard REGNO.  */
   the desired hard REGNO.  */
 
 
static void
static void
replace_reg (rtx *reg, int regno)
replace_reg (rtx *reg, int regno)
{
{
  gcc_assert (regno >= FIRST_STACK_REG);
  gcc_assert (regno >= FIRST_STACK_REG);
  gcc_assert (regno <= LAST_STACK_REG);
  gcc_assert (regno <= LAST_STACK_REG);
  gcc_assert (STACK_REG_P (*reg));
  gcc_assert (STACK_REG_P (*reg));
 
 
  gcc_assert (SCALAR_FLOAT_MODE_P (GET_MODE (*reg))
  gcc_assert (SCALAR_FLOAT_MODE_P (GET_MODE (*reg))
              || GET_MODE_CLASS (GET_MODE (*reg)) == MODE_COMPLEX_FLOAT);
              || GET_MODE_CLASS (GET_MODE (*reg)) == MODE_COMPLEX_FLOAT);
 
 
  *reg = FP_MODE_REG (regno, GET_MODE (*reg));
  *reg = FP_MODE_REG (regno, GET_MODE (*reg));
}
}
 
 
/* Remove a note of type NOTE, which must be found, for register
/* Remove a note of type NOTE, which must be found, for register
   number REGNO from INSN.  Remove only one such note.  */
   number REGNO from INSN.  Remove only one such note.  */
 
 
static void
static void
remove_regno_note (rtx insn, enum reg_note note, unsigned int regno)
remove_regno_note (rtx insn, enum reg_note note, unsigned int regno)
{
{
  rtx *note_link, this;
  rtx *note_link, this;
 
 
  note_link = &REG_NOTES (insn);
  note_link = &REG_NOTES (insn);
  for (this = *note_link; this; this = XEXP (this, 1))
  for (this = *note_link; this; this = XEXP (this, 1))
    if (REG_NOTE_KIND (this) == note
    if (REG_NOTE_KIND (this) == note
        && REG_P (XEXP (this, 0)) && REGNO (XEXP (this, 0)) == regno)
        && REG_P (XEXP (this, 0)) && REGNO (XEXP (this, 0)) == regno)
      {
      {
        *note_link = XEXP (this, 1);
        *note_link = XEXP (this, 1);
        return;
        return;
      }
      }
    else
    else
      note_link = &XEXP (this, 1);
      note_link = &XEXP (this, 1);
 
 
  gcc_unreachable ();
  gcc_unreachable ();
}
}
 
 
/* Find the hard register number of virtual register REG in REGSTACK.
/* Find the hard register number of virtual register REG in REGSTACK.
   The hard register number is relative to the top of the stack.  -1 is
   The hard register number is relative to the top of the stack.  -1 is
   returned if the register is not found.  */
   returned if the register is not found.  */
 
 
static int
static int
get_hard_regnum (stack regstack, rtx reg)
get_hard_regnum (stack regstack, rtx reg)
{
{
  int i;
  int i;
 
 
  gcc_assert (STACK_REG_P (reg));
  gcc_assert (STACK_REG_P (reg));
 
 
  for (i = regstack->top; i >= 0; i--)
  for (i = regstack->top; i >= 0; i--)
    if (regstack->reg[i] == REGNO (reg))
    if (regstack->reg[i] == REGNO (reg))
      break;
      break;
 
 
  return i >= 0 ? (FIRST_STACK_REG + regstack->top - i) : -1;
  return i >= 0 ? (FIRST_STACK_REG + regstack->top - i) : -1;
}
}


/* Emit an insn to pop virtual register REG before or after INSN.
/* Emit an insn to pop virtual register REG before or after INSN.
   REGSTACK is the stack state after INSN and is updated to reflect this
   REGSTACK is the stack state after INSN and is updated to reflect this
   pop.  WHEN is either emit_insn_before or emit_insn_after.  A pop insn
   pop.  WHEN is either emit_insn_before or emit_insn_after.  A pop insn
   is represented as a SET whose destination is the register to be popped
   is represented as a SET whose destination is the register to be popped
   and source is the top of stack.  A death note for the top of stack
   and source is the top of stack.  A death note for the top of stack
   cases the movdf pattern to pop.  */
   cases the movdf pattern to pop.  */
 
 
static rtx
static rtx
emit_pop_insn (rtx insn, stack regstack, rtx reg, enum emit_where where)
emit_pop_insn (rtx insn, stack regstack, rtx reg, enum emit_where where)
{
{
  rtx pop_insn, pop_rtx;
  rtx pop_insn, pop_rtx;
  int hard_regno;
  int hard_regno;
 
 
  /* For complex types take care to pop both halves.  These may survive in
  /* For complex types take care to pop both halves.  These may survive in
     CLOBBER and USE expressions.  */
     CLOBBER and USE expressions.  */
  if (COMPLEX_MODE_P (GET_MODE (reg)))
  if (COMPLEX_MODE_P (GET_MODE (reg)))
    {
    {
      rtx reg1 = FP_MODE_REG (REGNO (reg), DFmode);
      rtx reg1 = FP_MODE_REG (REGNO (reg), DFmode);
      rtx reg2 = FP_MODE_REG (REGNO (reg) + 1, DFmode);
      rtx reg2 = FP_MODE_REG (REGNO (reg) + 1, DFmode);
 
 
      pop_insn = NULL_RTX;
      pop_insn = NULL_RTX;
      if (get_hard_regnum (regstack, reg1) >= 0)
      if (get_hard_regnum (regstack, reg1) >= 0)
        pop_insn = emit_pop_insn (insn, regstack, reg1, where);
        pop_insn = emit_pop_insn (insn, regstack, reg1, where);
      if (get_hard_regnum (regstack, reg2) >= 0)
      if (get_hard_regnum (regstack, reg2) >= 0)
        pop_insn = emit_pop_insn (insn, regstack, reg2, where);
        pop_insn = emit_pop_insn (insn, regstack, reg2, where);
      gcc_assert (pop_insn);
      gcc_assert (pop_insn);
      return pop_insn;
      return pop_insn;
    }
    }
 
 
  hard_regno = get_hard_regnum (regstack, reg);
  hard_regno = get_hard_regnum (regstack, reg);
 
 
  gcc_assert (hard_regno >= FIRST_STACK_REG);
  gcc_assert (hard_regno >= FIRST_STACK_REG);
 
 
  pop_rtx = gen_rtx_SET (VOIDmode, FP_MODE_REG (hard_regno, DFmode),
  pop_rtx = gen_rtx_SET (VOIDmode, FP_MODE_REG (hard_regno, DFmode),
                         FP_MODE_REG (FIRST_STACK_REG, DFmode));
                         FP_MODE_REG (FIRST_STACK_REG, DFmode));
 
 
  if (where == EMIT_AFTER)
  if (where == EMIT_AFTER)
    pop_insn = emit_insn_after (pop_rtx, insn);
    pop_insn = emit_insn_after (pop_rtx, insn);
  else
  else
    pop_insn = emit_insn_before (pop_rtx, insn);
    pop_insn = emit_insn_before (pop_rtx, insn);
 
 
  REG_NOTES (pop_insn)
  REG_NOTES (pop_insn)
    = gen_rtx_EXPR_LIST (REG_DEAD, FP_MODE_REG (FIRST_STACK_REG, DFmode),
    = gen_rtx_EXPR_LIST (REG_DEAD, FP_MODE_REG (FIRST_STACK_REG, DFmode),
                         REG_NOTES (pop_insn));
                         REG_NOTES (pop_insn));
 
 
  regstack->reg[regstack->top - (hard_regno - FIRST_STACK_REG)]
  regstack->reg[regstack->top - (hard_regno - FIRST_STACK_REG)]
    = regstack->reg[regstack->top];
    = regstack->reg[regstack->top];
  regstack->top -= 1;
  regstack->top -= 1;
  CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (reg));
  CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (reg));
 
 
  return pop_insn;
  return pop_insn;
}
}


/* Emit an insn before or after INSN to swap virtual register REG with
/* Emit an insn before or after INSN to swap virtual register REG with
   the top of stack.  REGSTACK is the stack state before the swap, and
   the top of stack.  REGSTACK is the stack state before the swap, and
   is updated to reflect the swap.  A swap insn is represented as a
   is updated to reflect the swap.  A swap insn is represented as a
   PARALLEL of two patterns: each pattern moves one reg to the other.
   PARALLEL of two patterns: each pattern moves one reg to the other.
 
 
   If REG is already at the top of the stack, no insn is emitted.  */
   If REG is already at the top of the stack, no insn is emitted.  */
 
 
static void
static void
emit_swap_insn (rtx insn, stack regstack, rtx reg)
emit_swap_insn (rtx insn, stack regstack, rtx reg)
{
{
  int hard_regno;
  int hard_regno;
  rtx swap_rtx;
  rtx swap_rtx;
  int tmp, other_reg;           /* swap regno temps */
  int tmp, other_reg;           /* swap regno temps */
  rtx i1;                       /* the stack-reg insn prior to INSN */
  rtx i1;                       /* the stack-reg insn prior to INSN */
  rtx i1set = NULL_RTX;         /* the SET rtx within I1 */
  rtx i1set = NULL_RTX;         /* the SET rtx within I1 */
 
 
  hard_regno = get_hard_regnum (regstack, reg);
  hard_regno = get_hard_regnum (regstack, reg);
 
 
  if (hard_regno == FIRST_STACK_REG)
  if (hard_regno == FIRST_STACK_REG)
    return;
    return;
  if (hard_regno == -1)
  if (hard_regno == -1)
    {
    {
      /* Something failed if the register wasn't on the stack.  If we had
      /* Something failed if the register wasn't on the stack.  If we had
         malformed asms, we zapped the instruction itself, but that didn't
         malformed asms, we zapped the instruction itself, but that didn't
         produce the same pattern of register sets as before.  To prevent
         produce the same pattern of register sets as before.  To prevent
         further failure, adjust REGSTACK to include REG at TOP.  */
         further failure, adjust REGSTACK to include REG at TOP.  */
      gcc_assert (any_malformed_asm);
      gcc_assert (any_malformed_asm);
      regstack->reg[++regstack->top] = REGNO (reg);
      regstack->reg[++regstack->top] = REGNO (reg);
      return;
      return;
    }
    }
  gcc_assert (hard_regno >= FIRST_STACK_REG);
  gcc_assert (hard_regno >= FIRST_STACK_REG);
 
 
  other_reg = regstack->top - (hard_regno - FIRST_STACK_REG);
  other_reg = regstack->top - (hard_regno - FIRST_STACK_REG);
 
 
  tmp = regstack->reg[other_reg];
  tmp = regstack->reg[other_reg];
  regstack->reg[other_reg] = regstack->reg[regstack->top];
  regstack->reg[other_reg] = regstack->reg[regstack->top];
  regstack->reg[regstack->top] = tmp;
  regstack->reg[regstack->top] = tmp;
 
 
  /* Find the previous insn involving stack regs, but don't pass a
  /* Find the previous insn involving stack regs, but don't pass a
     block boundary.  */
     block boundary.  */
  i1 = NULL;
  i1 = NULL;
  if (current_block && insn != BB_HEAD (current_block))
  if (current_block && insn != BB_HEAD (current_block))
    {
    {
      rtx tmp = PREV_INSN (insn);
      rtx tmp = PREV_INSN (insn);
      rtx limit = PREV_INSN (BB_HEAD (current_block));
      rtx limit = PREV_INSN (BB_HEAD (current_block));
      while (tmp != limit)
      while (tmp != limit)
        {
        {
          if (LABEL_P (tmp)
          if (LABEL_P (tmp)
              || CALL_P (tmp)
              || CALL_P (tmp)
              || NOTE_INSN_BASIC_BLOCK_P (tmp)
              || NOTE_INSN_BASIC_BLOCK_P (tmp)
              || (NONJUMP_INSN_P (tmp)
              || (NONJUMP_INSN_P (tmp)
                  && stack_regs_mentioned (tmp)))
                  && stack_regs_mentioned (tmp)))
            {
            {
              i1 = tmp;
              i1 = tmp;
              break;
              break;
            }
            }
          tmp = PREV_INSN (tmp);
          tmp = PREV_INSN (tmp);
        }
        }
    }
    }
 
 
  if (i1 != NULL_RTX
  if (i1 != NULL_RTX
      && (i1set = single_set (i1)) != NULL_RTX)
      && (i1set = single_set (i1)) != NULL_RTX)
    {
    {
      rtx i1src = *get_true_reg (&SET_SRC (i1set));
      rtx i1src = *get_true_reg (&SET_SRC (i1set));
      rtx i1dest = *get_true_reg (&SET_DEST (i1set));
      rtx i1dest = *get_true_reg (&SET_DEST (i1set));
 
 
      /* If the previous register stack push was from the reg we are to
      /* If the previous register stack push was from the reg we are to
         swap with, omit the swap.  */
         swap with, omit the swap.  */
 
 
      if (REG_P (i1dest) && REGNO (i1dest) == FIRST_STACK_REG
      if (REG_P (i1dest) && REGNO (i1dest) == FIRST_STACK_REG
          && REG_P (i1src)
          && REG_P (i1src)
          && REGNO (i1src) == (unsigned) hard_regno - 1
          && REGNO (i1src) == (unsigned) hard_regno - 1
          && find_regno_note (i1, REG_DEAD, FIRST_STACK_REG) == NULL_RTX)
          && find_regno_note (i1, REG_DEAD, FIRST_STACK_REG) == NULL_RTX)
        return;
        return;
 
 
      /* If the previous insn wrote to the reg we are to swap with,
      /* If the previous insn wrote to the reg we are to swap with,
         omit the swap.  */
         omit the swap.  */
 
 
      if (REG_P (i1dest) && REGNO (i1dest) == (unsigned) hard_regno
      if (REG_P (i1dest) && REGNO (i1dest) == (unsigned) hard_regno
          && REG_P (i1src) && REGNO (i1src) == FIRST_STACK_REG
          && REG_P (i1src) && REGNO (i1src) == FIRST_STACK_REG
          && find_regno_note (i1, REG_DEAD, FIRST_STACK_REG) == NULL_RTX)
          && find_regno_note (i1, REG_DEAD, FIRST_STACK_REG) == NULL_RTX)
        return;
        return;
    }
    }
 
 
  /* Avoid emitting the swap if this is the first register stack insn
  /* Avoid emitting the swap if this is the first register stack insn
     of the current_block.  Instead update the current_block's stack_in
     of the current_block.  Instead update the current_block's stack_in
     and let compensate edges take care of this for us.  */
     and let compensate edges take care of this for us.  */
  if (current_block && starting_stack_p)
  if (current_block && starting_stack_p)
    {
    {
      BLOCK_INFO (current_block)->stack_in = *regstack;
      BLOCK_INFO (current_block)->stack_in = *regstack;
      starting_stack_p = false;
      starting_stack_p = false;
      return;
      return;
    }
    }
 
 
  swap_rtx = gen_swapxf (FP_MODE_REG (hard_regno, XFmode),
  swap_rtx = gen_swapxf (FP_MODE_REG (hard_regno, XFmode),
                         FP_MODE_REG (FIRST_STACK_REG, XFmode));
                         FP_MODE_REG (FIRST_STACK_REG, XFmode));
 
 
  if (i1)
  if (i1)
    emit_insn_after (swap_rtx, i1);
    emit_insn_after (swap_rtx, i1);
  else if (current_block)
  else if (current_block)
    emit_insn_before (swap_rtx, BB_HEAD (current_block));
    emit_insn_before (swap_rtx, BB_HEAD (current_block));
  else
  else
    emit_insn_before (swap_rtx, insn);
    emit_insn_before (swap_rtx, insn);
}
}


/* Emit an insns before INSN to swap virtual register SRC1 with
/* Emit an insns before INSN to swap virtual register SRC1 with
   the top of stack and virtual register SRC2 with second stack
   the top of stack and virtual register SRC2 with second stack
   slot. REGSTACK is the stack state before the swaps, and
   slot. REGSTACK is the stack state before the swaps, and
   is updated to reflect the swaps.  A swap insn is represented as a
   is updated to reflect the swaps.  A swap insn is represented as a
   PARALLEL of two patterns: each pattern moves one reg to the other.
   PARALLEL of two patterns: each pattern moves one reg to the other.
 
 
   If SRC1 and/or SRC2 are already at the right place, no swap insn
   If SRC1 and/or SRC2 are already at the right place, no swap insn
   is emitted.  */
   is emitted.  */
 
 
static void
static void
swap_to_top (rtx insn, stack regstack, rtx src1, rtx src2)
swap_to_top (rtx insn, stack regstack, rtx src1, rtx src2)
{
{
  struct stack_def temp_stack;
  struct stack_def temp_stack;
  int regno, j, k, temp;
  int regno, j, k, temp;
 
 
  temp_stack = *regstack;
  temp_stack = *regstack;
 
 
  /* Place operand 1 at the top of stack.  */
  /* Place operand 1 at the top of stack.  */
  regno = get_hard_regnum (&temp_stack, src1);
  regno = get_hard_regnum (&temp_stack, src1);
  gcc_assert (regno >= 0);
  gcc_assert (regno >= 0);
  if (regno != FIRST_STACK_REG)
  if (regno != FIRST_STACK_REG)
    {
    {
      k = temp_stack.top - (regno - FIRST_STACK_REG);
      k = temp_stack.top - (regno - FIRST_STACK_REG);
      j = temp_stack.top;
      j = temp_stack.top;
 
 
      temp = temp_stack.reg[k];
      temp = temp_stack.reg[k];
      temp_stack.reg[k] = temp_stack.reg[j];
      temp_stack.reg[k] = temp_stack.reg[j];
      temp_stack.reg[j] = temp;
      temp_stack.reg[j] = temp;
    }
    }
 
 
  /* Place operand 2 next on the stack.  */
  /* Place operand 2 next on the stack.  */
  regno = get_hard_regnum (&temp_stack, src2);
  regno = get_hard_regnum (&temp_stack, src2);
  gcc_assert (regno >= 0);
  gcc_assert (regno >= 0);
  if (regno != FIRST_STACK_REG + 1)
  if (regno != FIRST_STACK_REG + 1)
    {
    {
      k = temp_stack.top - (regno - FIRST_STACK_REG);
      k = temp_stack.top - (regno - FIRST_STACK_REG);
      j = temp_stack.top - 1;
      j = temp_stack.top - 1;
 
 
      temp = temp_stack.reg[k];
      temp = temp_stack.reg[k];
      temp_stack.reg[k] = temp_stack.reg[j];
      temp_stack.reg[k] = temp_stack.reg[j];
      temp_stack.reg[j] = temp;
      temp_stack.reg[j] = temp;
    }
    }
 
 
  change_stack (insn, regstack, &temp_stack, EMIT_BEFORE);
  change_stack (insn, regstack, &temp_stack, EMIT_BEFORE);
}
}


/* Handle a move to or from a stack register in PAT, which is in INSN.
/* Handle a move to or from a stack register in PAT, which is in INSN.
   REGSTACK is the current stack.  Return whether a control flow insn
   REGSTACK is the current stack.  Return whether a control flow insn
   was deleted in the process.  */
   was deleted in the process.  */
 
 
static bool
static bool
move_for_stack_reg (rtx insn, stack regstack, rtx pat)
move_for_stack_reg (rtx insn, stack regstack, rtx pat)
{
{
  rtx *psrc =  get_true_reg (&SET_SRC (pat));
  rtx *psrc =  get_true_reg (&SET_SRC (pat));
  rtx *pdest = get_true_reg (&SET_DEST (pat));
  rtx *pdest = get_true_reg (&SET_DEST (pat));
  rtx src, dest;
  rtx src, dest;
  rtx note;
  rtx note;
  bool control_flow_insn_deleted = false;
  bool control_flow_insn_deleted = false;
 
 
  src = *psrc; dest = *pdest;
  src = *psrc; dest = *pdest;
 
 
  if (STACK_REG_P (src) && STACK_REG_P (dest))
  if (STACK_REG_P (src) && STACK_REG_P (dest))
    {
    {
      /* Write from one stack reg to another.  If SRC dies here, then
      /* Write from one stack reg to another.  If SRC dies here, then
         just change the register mapping and delete the insn.  */
         just change the register mapping and delete the insn.  */
 
 
      note = find_regno_note (insn, REG_DEAD, REGNO (src));
      note = find_regno_note (insn, REG_DEAD, REGNO (src));
      if (note)
      if (note)
        {
        {
          int i;
          int i;
 
 
          /* If this is a no-op move, there must not be a REG_DEAD note.  */
          /* If this is a no-op move, there must not be a REG_DEAD note.  */
          gcc_assert (REGNO (src) != REGNO (dest));
          gcc_assert (REGNO (src) != REGNO (dest));
 
 
          for (i = regstack->top; i >= 0; i--)
          for (i = regstack->top; i >= 0; i--)
            if (regstack->reg[i] == REGNO (src))
            if (regstack->reg[i] == REGNO (src))
              break;
              break;
 
 
          /* The destination must be dead, or life analysis is borked.  */
          /* The destination must be dead, or life analysis is borked.  */
          gcc_assert (get_hard_regnum (regstack, dest) < FIRST_STACK_REG);
          gcc_assert (get_hard_regnum (regstack, dest) < FIRST_STACK_REG);
 
 
          /* If the source is not live, this is yet another case of
          /* If the source is not live, this is yet another case of
             uninitialized variables.  Load up a NaN instead.  */
             uninitialized variables.  Load up a NaN instead.  */
          if (i < 0)
          if (i < 0)
            return move_nan_for_stack_reg (insn, regstack, dest);
            return move_nan_for_stack_reg (insn, regstack, dest);
 
 
          /* It is possible that the dest is unused after this insn.
          /* It is possible that the dest is unused after this insn.
             If so, just pop the src.  */
             If so, just pop the src.  */
 
 
          if (find_regno_note (insn, REG_UNUSED, REGNO (dest)))
          if (find_regno_note (insn, REG_UNUSED, REGNO (dest)))
            emit_pop_insn (insn, regstack, src, EMIT_AFTER);
            emit_pop_insn (insn, regstack, src, EMIT_AFTER);
          else
          else
            {
            {
              regstack->reg[i] = REGNO (dest);
              regstack->reg[i] = REGNO (dest);
              SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest));
              SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest));
              CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (src));
              CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (src));
            }
            }
 
 
          control_flow_insn_deleted |= control_flow_insn_p (insn);
          control_flow_insn_deleted |= control_flow_insn_p (insn);
          delete_insn (insn);
          delete_insn (insn);
          return control_flow_insn_deleted;
          return control_flow_insn_deleted;
        }
        }
 
 
      /* The source reg does not die.  */
      /* The source reg does not die.  */
 
 
      /* If this appears to be a no-op move, delete it, or else it
      /* If this appears to be a no-op move, delete it, or else it
         will confuse the machine description output patterns. But if
         will confuse the machine description output patterns. But if
         it is REG_UNUSED, we must pop the reg now, as per-insn processing
         it is REG_UNUSED, we must pop the reg now, as per-insn processing
         for REG_UNUSED will not work for deleted insns.  */
         for REG_UNUSED will not work for deleted insns.  */
 
 
      if (REGNO (src) == REGNO (dest))
      if (REGNO (src) == REGNO (dest))
        {
        {
          if (find_regno_note (insn, REG_UNUSED, REGNO (dest)))
          if (find_regno_note (insn, REG_UNUSED, REGNO (dest)))
            emit_pop_insn (insn, regstack, dest, EMIT_AFTER);
            emit_pop_insn (insn, regstack, dest, EMIT_AFTER);
 
 
          control_flow_insn_deleted |= control_flow_insn_p (insn);
          control_flow_insn_deleted |= control_flow_insn_p (insn);
          delete_insn (insn);
          delete_insn (insn);
          return control_flow_insn_deleted;
          return control_flow_insn_deleted;
        }
        }
 
 
      /* The destination ought to be dead.  */
      /* The destination ought to be dead.  */
      gcc_assert (get_hard_regnum (regstack, dest) < FIRST_STACK_REG);
      gcc_assert (get_hard_regnum (regstack, dest) < FIRST_STACK_REG);
 
 
      replace_reg (psrc, get_hard_regnum (regstack, src));
      replace_reg (psrc, get_hard_regnum (regstack, src));
 
 
      regstack->reg[++regstack->top] = REGNO (dest);
      regstack->reg[++regstack->top] = REGNO (dest);
      SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest));
      SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest));
      replace_reg (pdest, FIRST_STACK_REG);
      replace_reg (pdest, FIRST_STACK_REG);
    }
    }
  else if (STACK_REG_P (src))
  else if (STACK_REG_P (src))
    {
    {
      /* Save from a stack reg to MEM, or possibly integer reg.  Since
      /* Save from a stack reg to MEM, or possibly integer reg.  Since
         only top of stack may be saved, emit an exchange first if
         only top of stack may be saved, emit an exchange first if
         needs be.  */
         needs be.  */
 
 
      emit_swap_insn (insn, regstack, src);
      emit_swap_insn (insn, regstack, src);
 
 
      note = find_regno_note (insn, REG_DEAD, REGNO (src));
      note = find_regno_note (insn, REG_DEAD, REGNO (src));
      if (note)
      if (note)
        {
        {
          replace_reg (&XEXP (note, 0), FIRST_STACK_REG);
          replace_reg (&XEXP (note, 0), FIRST_STACK_REG);
          regstack->top--;
          regstack->top--;
          CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (src));
          CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (src));
        }
        }
      else if ((GET_MODE (src) == XFmode)
      else if ((GET_MODE (src) == XFmode)
               && regstack->top < REG_STACK_SIZE - 1)
               && regstack->top < REG_STACK_SIZE - 1)
        {
        {
          /* A 387 cannot write an XFmode value to a MEM without
          /* A 387 cannot write an XFmode value to a MEM without
             clobbering the source reg.  The output code can handle
             clobbering the source reg.  The output code can handle
             this by reading back the value from the MEM.
             this by reading back the value from the MEM.
             But it is more efficient to use a temp register if one is
             But it is more efficient to use a temp register if one is
             available.  Push the source value here if the register
             available.  Push the source value here if the register
             stack is not full, and then write the value to memory via
             stack is not full, and then write the value to memory via
             a pop.  */
             a pop.  */
          rtx push_rtx;
          rtx push_rtx;
          rtx top_stack_reg = FP_MODE_REG (FIRST_STACK_REG, GET_MODE (src));
          rtx top_stack_reg = FP_MODE_REG (FIRST_STACK_REG, GET_MODE (src));
 
 
          push_rtx = gen_movxf (top_stack_reg, top_stack_reg);
          push_rtx = gen_movxf (top_stack_reg, top_stack_reg);
          emit_insn_before (push_rtx, insn);
          emit_insn_before (push_rtx, insn);
          REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_DEAD, top_stack_reg,
          REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_DEAD, top_stack_reg,
                                                REG_NOTES (insn));
                                                REG_NOTES (insn));
        }
        }
 
 
      replace_reg (psrc, FIRST_STACK_REG);
      replace_reg (psrc, FIRST_STACK_REG);
    }
    }
  else
  else
    {
    {
      gcc_assert (STACK_REG_P (dest));
      gcc_assert (STACK_REG_P (dest));
 
 
      /* Load from MEM, or possibly integer REG or constant, into the
      /* Load from MEM, or possibly integer REG or constant, into the
         stack regs.  The actual target is always the top of the
         stack regs.  The actual target is always the top of the
         stack. The stack mapping is changed to reflect that DEST is
         stack. The stack mapping is changed to reflect that DEST is
         now at top of stack.  */
         now at top of stack.  */
 
 
      /* The destination ought to be dead.  */
      /* The destination ought to be dead.  */
      gcc_assert (get_hard_regnum (regstack, dest) < FIRST_STACK_REG);
      gcc_assert (get_hard_regnum (regstack, dest) < FIRST_STACK_REG);
 
 
      gcc_assert (regstack->top < REG_STACK_SIZE);
      gcc_assert (regstack->top < REG_STACK_SIZE);
 
 
      regstack->reg[++regstack->top] = REGNO (dest);
      regstack->reg[++regstack->top] = REGNO (dest);
      SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest));
      SET_HARD_REG_BIT (regstack->reg_set, REGNO (dest));
      replace_reg (pdest, FIRST_STACK_REG);
      replace_reg (pdest, FIRST_STACK_REG);
    }
    }
 
 
  return control_flow_insn_deleted;
  return control_flow_insn_deleted;
}
}
 
 
/* A helper function which replaces INSN with a pattern that loads up
/* A helper function which replaces INSN with a pattern that loads up
   a NaN into DEST, then invokes move_for_stack_reg.  */
   a NaN into DEST, then invokes move_for_stack_reg.  */
 
 
static bool
static bool
move_nan_for_stack_reg (rtx insn, stack regstack, rtx dest)
move_nan_for_stack_reg (rtx insn, stack regstack, rtx dest)
{
{
  rtx pat;
  rtx pat;
 
 
  dest = FP_MODE_REG (REGNO (dest), SFmode);
  dest = FP_MODE_REG (REGNO (dest), SFmode);
  pat = gen_rtx_SET (VOIDmode, dest, not_a_num);
  pat = gen_rtx_SET (VOIDmode, dest, not_a_num);
  PATTERN (insn) = pat;
  PATTERN (insn) = pat;
  INSN_CODE (insn) = -1;
  INSN_CODE (insn) = -1;
 
 
  return move_for_stack_reg (insn, regstack, pat);
  return move_for_stack_reg (insn, regstack, pat);
}
}


/* Swap the condition on a branch, if there is one.  Return true if we
/* Swap the condition on a branch, if there is one.  Return true if we
   found a condition to swap.  False if the condition was not used as
   found a condition to swap.  False if the condition was not used as
   such.  */
   such.  */
 
 
static int
static int
swap_rtx_condition_1 (rtx pat)
swap_rtx_condition_1 (rtx pat)
{
{
  const char *fmt;
  const char *fmt;
  int i, r = 0;
  int i, r = 0;
 
 
  if (COMPARISON_P (pat))
  if (COMPARISON_P (pat))
    {
    {
      PUT_CODE (pat, swap_condition (GET_CODE (pat)));
      PUT_CODE (pat, swap_condition (GET_CODE (pat)));
      r = 1;
      r = 1;
    }
    }
  else
  else
    {
    {
      fmt = GET_RTX_FORMAT (GET_CODE (pat));
      fmt = GET_RTX_FORMAT (GET_CODE (pat));
      for (i = GET_RTX_LENGTH (GET_CODE (pat)) - 1; i >= 0; i--)
      for (i = GET_RTX_LENGTH (GET_CODE (pat)) - 1; i >= 0; i--)
        {
        {
          if (fmt[i] == 'E')
          if (fmt[i] == 'E')
            {
            {
              int j;
              int j;
 
 
              for (j = XVECLEN (pat, i) - 1; j >= 0; j--)
              for (j = XVECLEN (pat, i) - 1; j >= 0; j--)
                r |= swap_rtx_condition_1 (XVECEXP (pat, i, j));
                r |= swap_rtx_condition_1 (XVECEXP (pat, i, j));
            }
            }
          else if (fmt[i] == 'e')
          else if (fmt[i] == 'e')
            r |= swap_rtx_condition_1 (XEXP (pat, i));
            r |= swap_rtx_condition_1 (XEXP (pat, i));
        }
        }
    }
    }
 
 
  return r;
  return r;
}
}
 
 
static int
static int
swap_rtx_condition (rtx insn)
swap_rtx_condition (rtx insn)
{
{
  rtx pat = PATTERN (insn);
  rtx pat = PATTERN (insn);
 
 
  /* We're looking for a single set to cc0 or an HImode temporary.  */
  /* We're looking for a single set to cc0 or an HImode temporary.  */
 
 
  if (GET_CODE (pat) == SET
  if (GET_CODE (pat) == SET
      && REG_P (SET_DEST (pat))
      && REG_P (SET_DEST (pat))
      && REGNO (SET_DEST (pat)) == FLAGS_REG)
      && REGNO (SET_DEST (pat)) == FLAGS_REG)
    {
    {
      insn = next_flags_user (insn);
      insn = next_flags_user (insn);
      if (insn == NULL_RTX)
      if (insn == NULL_RTX)
        return 0;
        return 0;
      pat = PATTERN (insn);
      pat = PATTERN (insn);
    }
    }
 
 
  /* See if this is, or ends in, a fnstsw.  If so, we're not doing anything
  /* See if this is, or ends in, a fnstsw.  If so, we're not doing anything
     with the cc value right now.  We may be able to search for one
     with the cc value right now.  We may be able to search for one
     though.  */
     though.  */
 
 
  if (GET_CODE (pat) == SET
  if (GET_CODE (pat) == SET
      && GET_CODE (SET_SRC (pat)) == UNSPEC
      && GET_CODE (SET_SRC (pat)) == UNSPEC
      && XINT (SET_SRC (pat), 1) == UNSPEC_FNSTSW)
      && XINT (SET_SRC (pat), 1) == UNSPEC_FNSTSW)
    {
    {
      rtx dest = SET_DEST (pat);
      rtx dest = SET_DEST (pat);
 
 
      /* Search forward looking for the first use of this value.
      /* Search forward looking for the first use of this value.
         Stop at block boundaries.  */
         Stop at block boundaries.  */
      while (insn != BB_END (current_block))
      while (insn != BB_END (current_block))
        {
        {
          insn = NEXT_INSN (insn);
          insn = NEXT_INSN (insn);
          if (INSN_P (insn) && reg_mentioned_p (dest, insn))
          if (INSN_P (insn) && reg_mentioned_p (dest, insn))
            break;
            break;
          if (CALL_P (insn))
          if (CALL_P (insn))
            return 0;
            return 0;
        }
        }
 
 
      /* We haven't found it.  */
      /* We haven't found it.  */
      if (insn == BB_END (current_block))
      if (insn == BB_END (current_block))
        return 0;
        return 0;
 
 
      /* So we've found the insn using this value.  If it is anything
      /* So we've found the insn using this value.  If it is anything
         other than sahf or the value does not die (meaning we'd have
         other than sahf or the value does not die (meaning we'd have
         to search further), then we must give up.  */
         to search further), then we must give up.  */
      pat = PATTERN (insn);
      pat = PATTERN (insn);
      if (GET_CODE (pat) != SET
      if (GET_CODE (pat) != SET
          || GET_CODE (SET_SRC (pat)) != UNSPEC
          || GET_CODE (SET_SRC (pat)) != UNSPEC
          || XINT (SET_SRC (pat), 1) != UNSPEC_SAHF
          || XINT (SET_SRC (pat), 1) != UNSPEC_SAHF
          || ! dead_or_set_p (insn, dest))
          || ! dead_or_set_p (insn, dest))
        return 0;
        return 0;
 
 
      /* Now we are prepared to handle this as a normal cc0 setter.  */
      /* Now we are prepared to handle this as a normal cc0 setter.  */
      insn = next_flags_user (insn);
      insn = next_flags_user (insn);
      if (insn == NULL_RTX)
      if (insn == NULL_RTX)
        return 0;
        return 0;
      pat = PATTERN (insn);
      pat = PATTERN (insn);
    }
    }
 
 
  if (swap_rtx_condition_1 (pat))
  if (swap_rtx_condition_1 (pat))
    {
    {
      int fail = 0;
      int fail = 0;
      INSN_CODE (insn) = -1;
      INSN_CODE (insn) = -1;
      if (recog_memoized (insn) == -1)
      if (recog_memoized (insn) == -1)
        fail = 1;
        fail = 1;
      /* In case the flags don't die here, recurse to try fix
      /* In case the flags don't die here, recurse to try fix
         following user too.  */
         following user too.  */
      else if (! dead_or_set_p (insn, ix86_flags_rtx))
      else if (! dead_or_set_p (insn, ix86_flags_rtx))
        {
        {
          insn = next_flags_user (insn);
          insn = next_flags_user (insn);
          if (!insn || !swap_rtx_condition (insn))
          if (!insn || !swap_rtx_condition (insn))
            fail = 1;
            fail = 1;
        }
        }
      if (fail)
      if (fail)
        {
        {
          swap_rtx_condition_1 (pat);
          swap_rtx_condition_1 (pat);
          return 0;
          return 0;
        }
        }
      return 1;
      return 1;
    }
    }
  return 0;
  return 0;
}
}
 
 
/* Handle a comparison.  Special care needs to be taken to avoid
/* Handle a comparison.  Special care needs to be taken to avoid
   causing comparisons that a 387 cannot do correctly, such as EQ.
   causing comparisons that a 387 cannot do correctly, such as EQ.
 
 
   Also, a pop insn may need to be emitted.  The 387 does have an
   Also, a pop insn may need to be emitted.  The 387 does have an
   `fcompp' insn that can pop two regs, but it is sometimes too expensive
   `fcompp' insn that can pop two regs, but it is sometimes too expensive
   to do this - a `fcomp' followed by a `fstpl %st(0)' may be easier to
   to do this - a `fcomp' followed by a `fstpl %st(0)' may be easier to
   set up.  */
   set up.  */
 
 
static void
static void
compare_for_stack_reg (rtx insn, stack regstack, rtx pat_src)
compare_for_stack_reg (rtx insn, stack regstack, rtx pat_src)
{
{
  rtx *src1, *src2;
  rtx *src1, *src2;
  rtx src1_note, src2_note;
  rtx src1_note, src2_note;
 
 
  src1 = get_true_reg (&XEXP (pat_src, 0));
  src1 = get_true_reg (&XEXP (pat_src, 0));
  src2 = get_true_reg (&XEXP (pat_src, 1));
  src2 = get_true_reg (&XEXP (pat_src, 1));
 
 
  /* ??? If fxch turns out to be cheaper than fstp, give priority to
  /* ??? If fxch turns out to be cheaper than fstp, give priority to
     registers that die in this insn - move those to stack top first.  */
     registers that die in this insn - move those to stack top first.  */
  if ((! STACK_REG_P (*src1)
  if ((! STACK_REG_P (*src1)
       || (STACK_REG_P (*src2)
       || (STACK_REG_P (*src2)
           && get_hard_regnum (regstack, *src2) == FIRST_STACK_REG))
           && get_hard_regnum (regstack, *src2) == FIRST_STACK_REG))
      && swap_rtx_condition (insn))
      && swap_rtx_condition (insn))
    {
    {
      rtx temp;
      rtx temp;
      temp = XEXP (pat_src, 0);
      temp = XEXP (pat_src, 0);
      XEXP (pat_src, 0) = XEXP (pat_src, 1);
      XEXP (pat_src, 0) = XEXP (pat_src, 1);
      XEXP (pat_src, 1) = temp;
      XEXP (pat_src, 1) = temp;
 
 
      src1 = get_true_reg (&XEXP (pat_src, 0));
      src1 = get_true_reg (&XEXP (pat_src, 0));
      src2 = get_true_reg (&XEXP (pat_src, 1));
      src2 = get_true_reg (&XEXP (pat_src, 1));
 
 
      INSN_CODE (insn) = -1;
      INSN_CODE (insn) = -1;
    }
    }
 
 
  /* We will fix any death note later.  */
  /* We will fix any death note later.  */
 
 
  src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
  src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
 
 
  if (STACK_REG_P (*src2))
  if (STACK_REG_P (*src2))
    src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
    src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
  else
  else
    src2_note = NULL_RTX;
    src2_note = NULL_RTX;
 
 
  emit_swap_insn (insn, regstack, *src1);
  emit_swap_insn (insn, regstack, *src1);
 
 
  replace_reg (src1, FIRST_STACK_REG);
  replace_reg (src1, FIRST_STACK_REG);
 
 
  if (STACK_REG_P (*src2))
  if (STACK_REG_P (*src2))
    replace_reg (src2, get_hard_regnum (regstack, *src2));
    replace_reg (src2, get_hard_regnum (regstack, *src2));
 
 
  if (src1_note)
  if (src1_note)
    {
    {
      pop_stack (regstack, REGNO (XEXP (src1_note, 0)));
      pop_stack (regstack, REGNO (XEXP (src1_note, 0)));
      replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
      replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
    }
    }
 
 
  /* If the second operand dies, handle that.  But if the operands are
  /* If the second operand dies, handle that.  But if the operands are
     the same stack register, don't bother, because only one death is
     the same stack register, don't bother, because only one death is
     needed, and it was just handled.  */
     needed, and it was just handled.  */
 
 
  if (src2_note
  if (src2_note
      && ! (STACK_REG_P (*src1) && STACK_REG_P (*src2)
      && ! (STACK_REG_P (*src1) && STACK_REG_P (*src2)
            && REGNO (*src1) == REGNO (*src2)))
            && REGNO (*src1) == REGNO (*src2)))
    {
    {
      /* As a special case, two regs may die in this insn if src2 is
      /* As a special case, two regs may die in this insn if src2 is
         next to top of stack and the top of stack also dies.  Since
         next to top of stack and the top of stack also dies.  Since
         we have already popped src1, "next to top of stack" is really
         we have already popped src1, "next to top of stack" is really
         at top (FIRST_STACK_REG) now.  */
         at top (FIRST_STACK_REG) now.  */
 
 
      if (get_hard_regnum (regstack, XEXP (src2_note, 0)) == FIRST_STACK_REG
      if (get_hard_regnum (regstack, XEXP (src2_note, 0)) == FIRST_STACK_REG
          && src1_note)
          && src1_note)
        {
        {
          pop_stack (regstack, REGNO (XEXP (src2_note, 0)));
          pop_stack (regstack, REGNO (XEXP (src2_note, 0)));
          replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG + 1);
          replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG + 1);
        }
        }
      else
      else
        {
        {
          /* The 386 can only represent death of the first operand in
          /* The 386 can only represent death of the first operand in
             the case handled above.  In all other cases, emit a separate
             the case handled above.  In all other cases, emit a separate
             pop and remove the death note from here.  */
             pop and remove the death note from here.  */
 
 
          /* link_cc0_insns (insn); */
          /* link_cc0_insns (insn); */
 
 
          remove_regno_note (insn, REG_DEAD, REGNO (XEXP (src2_note, 0)));
          remove_regno_note (insn, REG_DEAD, REGNO (XEXP (src2_note, 0)));
 
 
          emit_pop_insn (insn, regstack, XEXP (src2_note, 0),
          emit_pop_insn (insn, regstack, XEXP (src2_note, 0),
                         EMIT_AFTER);
                         EMIT_AFTER);
        }
        }
    }
    }
}
}


/* Substitute new registers in PAT, which is part of INSN.  REGSTACK
/* Substitute new registers in PAT, which is part of INSN.  REGSTACK
   is the current register layout.  Return whether a control flow insn
   is the current register layout.  Return whether a control flow insn
   was deleted in the process.  */
   was deleted in the process.  */
 
 
static bool
static bool
subst_stack_regs_pat (rtx insn, stack regstack, rtx pat)
subst_stack_regs_pat (rtx insn, stack regstack, rtx pat)
{
{
  rtx *dest, *src;
  rtx *dest, *src;
  bool control_flow_insn_deleted = false;
  bool control_flow_insn_deleted = false;
 
 
  switch (GET_CODE (pat))
  switch (GET_CODE (pat))
    {
    {
    case USE:
    case USE:
      /* Deaths in USE insns can happen in non optimizing compilation.
      /* Deaths in USE insns can happen in non optimizing compilation.
         Handle them by popping the dying register.  */
         Handle them by popping the dying register.  */
      src = get_true_reg (&XEXP (pat, 0));
      src = get_true_reg (&XEXP (pat, 0));
      if (STACK_REG_P (*src)
      if (STACK_REG_P (*src)
          && find_regno_note (insn, REG_DEAD, REGNO (*src)))
          && find_regno_note (insn, REG_DEAD, REGNO (*src)))
        {
        {
          emit_pop_insn (insn, regstack, *src, EMIT_AFTER);
          emit_pop_insn (insn, regstack, *src, EMIT_AFTER);
          return control_flow_insn_deleted;
          return control_flow_insn_deleted;
        }
        }
      /* ??? Uninitialized USE should not happen.  */
      /* ??? Uninitialized USE should not happen.  */
      else
      else
        gcc_assert (get_hard_regnum (regstack, *src) != -1);
        gcc_assert (get_hard_regnum (regstack, *src) != -1);
      break;
      break;
 
 
    case CLOBBER:
    case CLOBBER:
      {
      {
        rtx note;
        rtx note;
 
 
        dest = get_true_reg (&XEXP (pat, 0));
        dest = get_true_reg (&XEXP (pat, 0));
        if (STACK_REG_P (*dest))
        if (STACK_REG_P (*dest))
          {
          {
            note = find_reg_note (insn, REG_DEAD, *dest);
            note = find_reg_note (insn, REG_DEAD, *dest);
 
 
            if (pat != PATTERN (insn))
            if (pat != PATTERN (insn))
              {
              {
                /* The fix_truncdi_1 pattern wants to be able to allocate
                /* The fix_truncdi_1 pattern wants to be able to allocate
                   its own scratch register.  It does this by clobbering
                   its own scratch register.  It does this by clobbering
                   an fp reg so that it is assured of an empty reg-stack
                   an fp reg so that it is assured of an empty reg-stack
                   register.  If the register is live, kill it now.
                   register.  If the register is live, kill it now.
                   Remove the DEAD/UNUSED note so we don't try to kill it
                   Remove the DEAD/UNUSED note so we don't try to kill it
                   later too.  */
                   later too.  */
 
 
                if (note)
                if (note)
                  emit_pop_insn (insn, regstack, *dest, EMIT_BEFORE);
                  emit_pop_insn (insn, regstack, *dest, EMIT_BEFORE);
                else
                else
                  {
                  {
                    note = find_reg_note (insn, REG_UNUSED, *dest);
                    note = find_reg_note (insn, REG_UNUSED, *dest);
                    gcc_assert (note);
                    gcc_assert (note);
                  }
                  }
                remove_note (insn, note);
                remove_note (insn, note);
                replace_reg (dest, FIRST_STACK_REG + 1);
                replace_reg (dest, FIRST_STACK_REG + 1);
              }
              }
            else
            else
              {
              {
                /* A top-level clobber with no REG_DEAD, and no hard-regnum
                /* A top-level clobber with no REG_DEAD, and no hard-regnum
                   indicates an uninitialized value.  Because reload removed
                   indicates an uninitialized value.  Because reload removed
                   all other clobbers, this must be due to a function
                   all other clobbers, this must be due to a function
                   returning without a value.  Load up a NaN.  */
                   returning without a value.  Load up a NaN.  */
 
 
                if (!note)
                if (!note)
                  {
                  {
                    rtx t = *dest;
                    rtx t = *dest;
                    if (COMPLEX_MODE_P (GET_MODE (t)))
                    if (COMPLEX_MODE_P (GET_MODE (t)))
                      {
                      {
                        rtx u = FP_MODE_REG (REGNO (t) + 1, SFmode);
                        rtx u = FP_MODE_REG (REGNO (t) + 1, SFmode);
                        if (get_hard_regnum (regstack, u) == -1)
                        if (get_hard_regnum (regstack, u) == -1)
                          {
                          {
                            rtx pat2 = gen_rtx_CLOBBER (VOIDmode, u);
                            rtx pat2 = gen_rtx_CLOBBER (VOIDmode, u);
                            rtx insn2 = emit_insn_before (pat2, insn);
                            rtx insn2 = emit_insn_before (pat2, insn);
                            control_flow_insn_deleted
                            control_flow_insn_deleted
                              |= move_nan_for_stack_reg (insn2, regstack, u);
                              |= move_nan_for_stack_reg (insn2, regstack, u);
                          }
                          }
                      }
                      }
                    if (get_hard_regnum (regstack, t) == -1)
                    if (get_hard_regnum (regstack, t) == -1)
                      control_flow_insn_deleted
                      control_flow_insn_deleted
                        |= move_nan_for_stack_reg (insn, regstack, t);
                        |= move_nan_for_stack_reg (insn, regstack, t);
                  }
                  }
              }
              }
          }
          }
        break;
        break;
      }
      }
 
 
    case SET:
    case SET:
      {
      {
        rtx *src1 = (rtx *) 0, *src2;
        rtx *src1 = (rtx *) 0, *src2;
        rtx src1_note, src2_note;
        rtx src1_note, src2_note;
        rtx pat_src;
        rtx pat_src;
 
 
        dest = get_true_reg (&SET_DEST (pat));
        dest = get_true_reg (&SET_DEST (pat));
        src  = get_true_reg (&SET_SRC (pat));
        src  = get_true_reg (&SET_SRC (pat));
        pat_src = SET_SRC (pat);
        pat_src = SET_SRC (pat);
 
 
        /* See if this is a `movM' pattern, and handle elsewhere if so.  */
        /* See if this is a `movM' pattern, and handle elsewhere if so.  */
        if (STACK_REG_P (*src)
        if (STACK_REG_P (*src)
            || (STACK_REG_P (*dest)
            || (STACK_REG_P (*dest)
                && (REG_P (*src) || MEM_P (*src)
                && (REG_P (*src) || MEM_P (*src)
                    || GET_CODE (*src) == CONST_DOUBLE)))
                    || GET_CODE (*src) == CONST_DOUBLE)))
          {
          {
            control_flow_insn_deleted |= move_for_stack_reg (insn, regstack, pat);
            control_flow_insn_deleted |= move_for_stack_reg (insn, regstack, pat);
            break;
            break;
          }
          }
 
 
        switch (GET_CODE (pat_src))
        switch (GET_CODE (pat_src))
          {
          {
          case COMPARE:
          case COMPARE:
            compare_for_stack_reg (insn, regstack, pat_src);
            compare_for_stack_reg (insn, regstack, pat_src);
            break;
            break;
 
 
          case CALL:
          case CALL:
            {
            {
              int count;
              int count;
              for (count = hard_regno_nregs[REGNO (*dest)][GET_MODE (*dest)];
              for (count = hard_regno_nregs[REGNO (*dest)][GET_MODE (*dest)];
                   --count >= 0;)
                   --count >= 0;)
                {
                {
                  regstack->reg[++regstack->top] = REGNO (*dest) + count;
                  regstack->reg[++regstack->top] = REGNO (*dest) + count;
                  SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest) + count);
                  SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest) + count);
                }
                }
            }
            }
            replace_reg (dest, FIRST_STACK_REG);
            replace_reg (dest, FIRST_STACK_REG);
            break;
            break;
 
 
          case REG:
          case REG:
            /* This is a `tstM2' case.  */
            /* This is a `tstM2' case.  */
            gcc_assert (*dest == cc0_rtx);
            gcc_assert (*dest == cc0_rtx);
            src1 = src;
            src1 = src;
 
 
            /* Fall through.  */
            /* Fall through.  */
 
 
          case FLOAT_TRUNCATE:
          case FLOAT_TRUNCATE:
          case SQRT:
          case SQRT:
          case ABS:
          case ABS:
          case NEG:
          case NEG:
            /* These insns only operate on the top of the stack. DEST might
            /* These insns only operate on the top of the stack. DEST might
               be cc0_rtx if we're processing a tstM pattern. Also, it's
               be cc0_rtx if we're processing a tstM pattern. Also, it's
               possible that the tstM case results in a REG_DEAD note on the
               possible that the tstM case results in a REG_DEAD note on the
               source.  */
               source.  */
 
 
            if (src1 == 0)
            if (src1 == 0)
              src1 = get_true_reg (&XEXP (pat_src, 0));
              src1 = get_true_reg (&XEXP (pat_src, 0));
 
 
            emit_swap_insn (insn, regstack, *src1);
            emit_swap_insn (insn, regstack, *src1);
 
 
            src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
            src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
 
 
            if (STACK_REG_P (*dest))
            if (STACK_REG_P (*dest))
              replace_reg (dest, FIRST_STACK_REG);
              replace_reg (dest, FIRST_STACK_REG);
 
 
            if (src1_note)
            if (src1_note)
              {
              {
                replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
                replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
                regstack->top--;
                regstack->top--;
                CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (*src1));
                CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (*src1));
              }
              }
 
 
            replace_reg (src1, FIRST_STACK_REG);
            replace_reg (src1, FIRST_STACK_REG);
            break;
            break;
 
 
          case MINUS:
          case MINUS:
          case DIV:
          case DIV:
            /* On i386, reversed forms of subM3 and divM3 exist for
            /* On i386, reversed forms of subM3 and divM3 exist for
               MODE_FLOAT, so the same code that works for addM3 and mulM3
               MODE_FLOAT, so the same code that works for addM3 and mulM3
               can be used.  */
               can be used.  */
          case MULT:
          case MULT:
          case PLUS:
          case PLUS:
            /* These insns can accept the top of stack as a destination
            /* These insns can accept the top of stack as a destination
               from a stack reg or mem, or can use the top of stack as a
               from a stack reg or mem, or can use the top of stack as a
               source and some other stack register (possibly top of stack)
               source and some other stack register (possibly top of stack)
               as a destination.  */
               as a destination.  */
 
 
            src1 = get_true_reg (&XEXP (pat_src, 0));
            src1 = get_true_reg (&XEXP (pat_src, 0));
            src2 = get_true_reg (&XEXP (pat_src, 1));
            src2 = get_true_reg (&XEXP (pat_src, 1));
 
 
            /* We will fix any death note later.  */
            /* We will fix any death note later.  */
 
 
            if (STACK_REG_P (*src1))
            if (STACK_REG_P (*src1))
              src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
              src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
            else
            else
              src1_note = NULL_RTX;
              src1_note = NULL_RTX;
            if (STACK_REG_P (*src2))
            if (STACK_REG_P (*src2))
              src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
              src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
            else
            else
              src2_note = NULL_RTX;
              src2_note = NULL_RTX;
 
 
            /* If either operand is not a stack register, then the dest
            /* If either operand is not a stack register, then the dest
               must be top of stack.  */
               must be top of stack.  */
 
 
            if (! STACK_REG_P (*src1) || ! STACK_REG_P (*src2))
            if (! STACK_REG_P (*src1) || ! STACK_REG_P (*src2))
              emit_swap_insn (insn, regstack, *dest);
              emit_swap_insn (insn, regstack, *dest);
            else
            else
              {
              {
                /* Both operands are REG.  If neither operand is already
                /* Both operands are REG.  If neither operand is already
                   at the top of stack, choose to make the one that is the dest
                   at the top of stack, choose to make the one that is the dest
                   the new top of stack.  */
                   the new top of stack.  */
 
 
                int src1_hard_regnum, src2_hard_regnum;
                int src1_hard_regnum, src2_hard_regnum;
 
 
                src1_hard_regnum = get_hard_regnum (regstack, *src1);
                src1_hard_regnum = get_hard_regnum (regstack, *src1);
                src2_hard_regnum = get_hard_regnum (regstack, *src2);
                src2_hard_regnum = get_hard_regnum (regstack, *src2);
                gcc_assert (src1_hard_regnum != -1);
                gcc_assert (src1_hard_regnum != -1);
                gcc_assert (src2_hard_regnum != -1);
                gcc_assert (src2_hard_regnum != -1);
 
 
                if (src1_hard_regnum != FIRST_STACK_REG
                if (src1_hard_regnum != FIRST_STACK_REG
                    && src2_hard_regnum != FIRST_STACK_REG)
                    && src2_hard_regnum != FIRST_STACK_REG)
                  emit_swap_insn (insn, regstack, *dest);
                  emit_swap_insn (insn, regstack, *dest);
              }
              }
 
 
            if (STACK_REG_P (*src1))
            if (STACK_REG_P (*src1))
              replace_reg (src1, get_hard_regnum (regstack, *src1));
              replace_reg (src1, get_hard_regnum (regstack, *src1));
            if (STACK_REG_P (*src2))
            if (STACK_REG_P (*src2))
              replace_reg (src2, get_hard_regnum (regstack, *src2));
              replace_reg (src2, get_hard_regnum (regstack, *src2));
 
 
            if (src1_note)
            if (src1_note)
              {
              {
                rtx src1_reg = XEXP (src1_note, 0);
                rtx src1_reg = XEXP (src1_note, 0);
 
 
                /* If the register that dies is at the top of stack, then
                /* If the register that dies is at the top of stack, then
                   the destination is somewhere else - merely substitute it.
                   the destination is somewhere else - merely substitute it.
                   But if the reg that dies is not at top of stack, then
                   But if the reg that dies is not at top of stack, then
                   move the top of stack to the dead reg, as though we had
                   move the top of stack to the dead reg, as though we had
                   done the insn and then a store-with-pop.  */
                   done the insn and then a store-with-pop.  */
 
 
                if (REGNO (src1_reg) == regstack->reg[regstack->top])
                if (REGNO (src1_reg) == regstack->reg[regstack->top])
                  {
                  {
                    SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                    SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                    replace_reg (dest, get_hard_regnum (regstack, *dest));
                    replace_reg (dest, get_hard_regnum (regstack, *dest));
                  }
                  }
                else
                else
                  {
                  {
                    int regno = get_hard_regnum (regstack, src1_reg);
                    int regno = get_hard_regnum (regstack, src1_reg);
 
 
                    SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                    SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                    replace_reg (dest, regno);
                    replace_reg (dest, regno);
 
 
                    regstack->reg[regstack->top - (regno - FIRST_STACK_REG)]
                    regstack->reg[regstack->top - (regno - FIRST_STACK_REG)]
                      = regstack->reg[regstack->top];
                      = regstack->reg[regstack->top];
                  }
                  }
 
 
                CLEAR_HARD_REG_BIT (regstack->reg_set,
                CLEAR_HARD_REG_BIT (regstack->reg_set,
                                    REGNO (XEXP (src1_note, 0)));
                                    REGNO (XEXP (src1_note, 0)));
                replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
                replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
                regstack->top--;
                regstack->top--;
              }
              }
            else if (src2_note)
            else if (src2_note)
              {
              {
                rtx src2_reg = XEXP (src2_note, 0);
                rtx src2_reg = XEXP (src2_note, 0);
                if (REGNO (src2_reg) == regstack->reg[regstack->top])
                if (REGNO (src2_reg) == regstack->reg[regstack->top])
                  {
                  {
                    SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                    SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                    replace_reg (dest, get_hard_regnum (regstack, *dest));
                    replace_reg (dest, get_hard_regnum (regstack, *dest));
                  }
                  }
                else
                else
                  {
                  {
                    int regno = get_hard_regnum (regstack, src2_reg);
                    int regno = get_hard_regnum (regstack, src2_reg);
 
 
                    SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                    SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                    replace_reg (dest, regno);
                    replace_reg (dest, regno);
 
 
                    regstack->reg[regstack->top - (regno - FIRST_STACK_REG)]
                    regstack->reg[regstack->top - (regno - FIRST_STACK_REG)]
                      = regstack->reg[regstack->top];
                      = regstack->reg[regstack->top];
                  }
                  }
 
 
                CLEAR_HARD_REG_BIT (regstack->reg_set,
                CLEAR_HARD_REG_BIT (regstack->reg_set,
                                    REGNO (XEXP (src2_note, 0)));
                                    REGNO (XEXP (src2_note, 0)));
                replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG);
                replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG);
                regstack->top--;
                regstack->top--;
              }
              }
            else
            else
              {
              {
                SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                replace_reg (dest, get_hard_regnum (regstack, *dest));
                replace_reg (dest, get_hard_regnum (regstack, *dest));
              }
              }
 
 
            /* Keep operand 1 matching with destination.  */
            /* Keep operand 1 matching with destination.  */
            if (COMMUTATIVE_ARITH_P (pat_src)
            if (COMMUTATIVE_ARITH_P (pat_src)
                && REG_P (*src1) && REG_P (*src2)
                && REG_P (*src1) && REG_P (*src2)
                && REGNO (*src1) != REGNO (*dest))
                && REGNO (*src1) != REGNO (*dest))
             {
             {
                int tmp = REGNO (*src1);
                int tmp = REGNO (*src1);
                replace_reg (src1, REGNO (*src2));
                replace_reg (src1, REGNO (*src2));
                replace_reg (src2, tmp);
                replace_reg (src2, tmp);
             }
             }
            break;
            break;
 
 
          case UNSPEC:
          case UNSPEC:
            switch (XINT (pat_src, 1))
            switch (XINT (pat_src, 1))
              {
              {
              case UNSPEC_FIST:
              case UNSPEC_FIST:
 
 
              case UNSPEC_FIST_FLOOR:
              case UNSPEC_FIST_FLOOR:
              case UNSPEC_FIST_CEIL:
              case UNSPEC_FIST_CEIL:
 
 
                /* These insns only operate on the top of the stack.  */
                /* These insns only operate on the top of the stack.  */
 
 
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
                emit_swap_insn (insn, regstack, *src1);
                emit_swap_insn (insn, regstack, *src1);
 
 
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
 
 
                if (STACK_REG_P (*dest))
                if (STACK_REG_P (*dest))
                  replace_reg (dest, FIRST_STACK_REG);
                  replace_reg (dest, FIRST_STACK_REG);
 
 
                if (src1_note)
                if (src1_note)
                  {
                  {
                    replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
                    replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
                    regstack->top--;
                    regstack->top--;
                    CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (*src1));
                    CLEAR_HARD_REG_BIT (regstack->reg_set, REGNO (*src1));
                  }
                  }
 
 
                replace_reg (src1, FIRST_STACK_REG);
                replace_reg (src1, FIRST_STACK_REG);
                break;
                break;
 
 
              case UNSPEC_SIN:
              case UNSPEC_SIN:
              case UNSPEC_COS:
              case UNSPEC_COS:
              case UNSPEC_FRNDINT:
              case UNSPEC_FRNDINT:
              case UNSPEC_F2XM1:
              case UNSPEC_F2XM1:
 
 
              case UNSPEC_FRNDINT_FLOOR:
              case UNSPEC_FRNDINT_FLOOR:
              case UNSPEC_FRNDINT_CEIL:
              case UNSPEC_FRNDINT_CEIL:
              case UNSPEC_FRNDINT_TRUNC:
              case UNSPEC_FRNDINT_TRUNC:
              case UNSPEC_FRNDINT_MASK_PM:
              case UNSPEC_FRNDINT_MASK_PM:
 
 
                /* These insns only operate on the top of the stack.  */
                /* These insns only operate on the top of the stack.  */
 
 
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
 
 
                emit_swap_insn (insn, regstack, *src1);
                emit_swap_insn (insn, regstack, *src1);
 
 
                /* Input should never die, it is
                /* Input should never die, it is
                   replaced with output.  */
                   replaced with output.  */
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
                gcc_assert (!src1_note);
                gcc_assert (!src1_note);
 
 
                if (STACK_REG_P (*dest))
                if (STACK_REG_P (*dest))
                  replace_reg (dest, FIRST_STACK_REG);
                  replace_reg (dest, FIRST_STACK_REG);
 
 
                replace_reg (src1, FIRST_STACK_REG);
                replace_reg (src1, FIRST_STACK_REG);
                break;
                break;
 
 
              case UNSPEC_FPATAN:
              case UNSPEC_FPATAN:
              case UNSPEC_FYL2X:
              case UNSPEC_FYL2X:
              case UNSPEC_FYL2XP1:
              case UNSPEC_FYL2XP1:
                /* These insns operate on the top two stack slots.  */
                /* These insns operate on the top two stack slots.  */
 
 
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
                src2 = get_true_reg (&XVECEXP (pat_src, 0, 1));
                src2 = get_true_reg (&XVECEXP (pat_src, 0, 1));
 
 
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
                src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
                src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
 
 
                swap_to_top (insn, regstack, *src1, *src2);
                swap_to_top (insn, regstack, *src1, *src2);
 
 
                replace_reg (src1, FIRST_STACK_REG);
                replace_reg (src1, FIRST_STACK_REG);
                replace_reg (src2, FIRST_STACK_REG + 1);
                replace_reg (src2, FIRST_STACK_REG + 1);
 
 
                if (src1_note)
                if (src1_note)
                  replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
                  replace_reg (&XEXP (src1_note, 0), FIRST_STACK_REG);
                if (src2_note)
                if (src2_note)
                  replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG + 1);
                  replace_reg (&XEXP (src2_note, 0), FIRST_STACK_REG + 1);
 
 
                /* Pop both input operands from the stack.  */
                /* Pop both input operands from the stack.  */
                CLEAR_HARD_REG_BIT (regstack->reg_set,
                CLEAR_HARD_REG_BIT (regstack->reg_set,
                                    regstack->reg[regstack->top]);
                                    regstack->reg[regstack->top]);
                CLEAR_HARD_REG_BIT (regstack->reg_set,
                CLEAR_HARD_REG_BIT (regstack->reg_set,
                                    regstack->reg[regstack->top - 1]);
                                    regstack->reg[regstack->top - 1]);
                regstack->top -= 2;
                regstack->top -= 2;
 
 
                /* Push the result back onto the stack.  */
                /* Push the result back onto the stack.  */
                regstack->reg[++regstack->top] = REGNO (*dest);
                regstack->reg[++regstack->top] = REGNO (*dest);
                SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                replace_reg (dest, FIRST_STACK_REG);
                replace_reg (dest, FIRST_STACK_REG);
                break;
                break;
 
 
              case UNSPEC_FSCALE_FRACT:
              case UNSPEC_FSCALE_FRACT:
              case UNSPEC_FPREM_F:
              case UNSPEC_FPREM_F:
              case UNSPEC_FPREM1_F:
              case UNSPEC_FPREM1_F:
                /* These insns operate on the top two stack slots.
                /* These insns operate on the top two stack slots.
                   first part of double input, double output insn.  */
                   first part of double input, double output insn.  */
 
 
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
                src2 = get_true_reg (&XVECEXP (pat_src, 0, 1));
                src2 = get_true_reg (&XVECEXP (pat_src, 0, 1));
 
 
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
                src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
                src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
 
 
                /* Inputs should never die, they are
                /* Inputs should never die, they are
                   replaced with outputs.  */
                   replaced with outputs.  */
                gcc_assert (!src1_note);
                gcc_assert (!src1_note);
                gcc_assert (!src2_note);
                gcc_assert (!src2_note);
 
 
                swap_to_top (insn, regstack, *src1, *src2);
                swap_to_top (insn, regstack, *src1, *src2);
 
 
                /* Push the result back onto stack. Empty stack slot
                /* Push the result back onto stack. Empty stack slot
                   will be filled in second part of insn.  */
                   will be filled in second part of insn.  */
                if (STACK_REG_P (*dest)) {
                if (STACK_REG_P (*dest)) {
                  regstack->reg[regstack->top] = REGNO (*dest);
                  regstack->reg[regstack->top] = REGNO (*dest);
                  SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                  SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                  replace_reg (dest, FIRST_STACK_REG);
                  replace_reg (dest, FIRST_STACK_REG);
                }
                }
 
 
                replace_reg (src1, FIRST_STACK_REG);
                replace_reg (src1, FIRST_STACK_REG);
                replace_reg (src2, FIRST_STACK_REG + 1);
                replace_reg (src2, FIRST_STACK_REG + 1);
                break;
                break;
 
 
              case UNSPEC_FSCALE_EXP:
              case UNSPEC_FSCALE_EXP:
              case UNSPEC_FPREM_U:
              case UNSPEC_FPREM_U:
              case UNSPEC_FPREM1_U:
              case UNSPEC_FPREM1_U:
                /* These insns operate on the top two stack slots./
                /* These insns operate on the top two stack slots./
                   second part of double input, double output insn.  */
                   second part of double input, double output insn.  */
 
 
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
                src2 = get_true_reg (&XVECEXP (pat_src, 0, 1));
                src2 = get_true_reg (&XVECEXP (pat_src, 0, 1));
 
 
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
                src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
                src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
 
 
                /* Inputs should never die, they are
                /* Inputs should never die, they are
                   replaced with outputs.  */
                   replaced with outputs.  */
                gcc_assert (!src1_note);
                gcc_assert (!src1_note);
                gcc_assert (!src2_note);
                gcc_assert (!src2_note);
 
 
                swap_to_top (insn, regstack, *src1, *src2);
                swap_to_top (insn, regstack, *src1, *src2);
 
 
                /* Push the result back onto stack. Fill empty slot from
                /* Push the result back onto stack. Fill empty slot from
                   first part of insn and fix top of stack pointer.  */
                   first part of insn and fix top of stack pointer.  */
                if (STACK_REG_P (*dest)) {
                if (STACK_REG_P (*dest)) {
                  regstack->reg[regstack->top - 1] = REGNO (*dest);
                  regstack->reg[regstack->top - 1] = REGNO (*dest);
                  SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                  SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                  replace_reg (dest, FIRST_STACK_REG + 1);
                  replace_reg (dest, FIRST_STACK_REG + 1);
                }
                }
 
 
                replace_reg (src1, FIRST_STACK_REG);
                replace_reg (src1, FIRST_STACK_REG);
                replace_reg (src2, FIRST_STACK_REG + 1);
                replace_reg (src2, FIRST_STACK_REG + 1);
                break;
                break;
 
 
              case UNSPEC_SINCOS_COS:
              case UNSPEC_SINCOS_COS:
              case UNSPEC_TAN_ONE:
              case UNSPEC_TAN_ONE:
              case UNSPEC_XTRACT_FRACT:
              case UNSPEC_XTRACT_FRACT:
                /* These insns operate on the top two stack slots,
                /* These insns operate on the top two stack slots,
                   first part of one input, double output insn.  */
                   first part of one input, double output insn.  */
 
 
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
 
 
                emit_swap_insn (insn, regstack, *src1);
                emit_swap_insn (insn, regstack, *src1);
 
 
                /* Input should never die, it is
                /* Input should never die, it is
                   replaced with output.  */
                   replaced with output.  */
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
                gcc_assert (!src1_note);
                gcc_assert (!src1_note);
 
 
                /* Push the result back onto stack. Empty stack slot
                /* Push the result back onto stack. Empty stack slot
                   will be filled in second part of insn.  */
                   will be filled in second part of insn.  */
                if (STACK_REG_P (*dest)) {
                if (STACK_REG_P (*dest)) {
                  regstack->reg[regstack->top + 1] = REGNO (*dest);
                  regstack->reg[regstack->top + 1] = REGNO (*dest);
                  SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                  SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                  replace_reg (dest, FIRST_STACK_REG);
                  replace_reg (dest, FIRST_STACK_REG);
                }
                }
 
 
                replace_reg (src1, FIRST_STACK_REG);
                replace_reg (src1, FIRST_STACK_REG);
                break;
                break;
 
 
              case UNSPEC_SINCOS_SIN:
              case UNSPEC_SINCOS_SIN:
              case UNSPEC_TAN_TAN:
              case UNSPEC_TAN_TAN:
              case UNSPEC_XTRACT_EXP:
              case UNSPEC_XTRACT_EXP:
                /* These insns operate on the top two stack slots,
                /* These insns operate on the top two stack slots,
                   second part of one input, double output insn.  */
                   second part of one input, double output insn.  */
 
 
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
                src1 = get_true_reg (&XVECEXP (pat_src, 0, 0));
 
 
                emit_swap_insn (insn, regstack, *src1);
                emit_swap_insn (insn, regstack, *src1);
 
 
                /* Input should never die, it is
                /* Input should never die, it is
                   replaced with output.  */
                   replaced with output.  */
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
                src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
                gcc_assert (!src1_note);
                gcc_assert (!src1_note);
 
 
                /* Push the result back onto stack. Fill empty slot from
                /* Push the result back onto stack. Fill empty slot from
                   first part of insn and fix top of stack pointer.  */
                   first part of insn and fix top of stack pointer.  */
                if (STACK_REG_P (*dest)) {
                if (STACK_REG_P (*dest)) {
                  regstack->reg[regstack->top] = REGNO (*dest);
                  regstack->reg[regstack->top] = REGNO (*dest);
                  SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                  SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
                  replace_reg (dest, FIRST_STACK_REG + 1);
                  replace_reg (dest, FIRST_STACK_REG + 1);
 
 
                  regstack->top++;
                  regstack->top++;
                }
                }
 
 
                replace_reg (src1, FIRST_STACK_REG);
                replace_reg (src1, FIRST_STACK_REG);
                break;
                break;
 
 
              case UNSPEC_SAHF:
              case UNSPEC_SAHF:
                /* (unspec [(unspec [(compare)] UNSPEC_FNSTSW)] UNSPEC_SAHF)
                /* (unspec [(unspec [(compare)] UNSPEC_FNSTSW)] UNSPEC_SAHF)
                   The combination matches the PPRO fcomi instruction.  */
                   The combination matches the PPRO fcomi instruction.  */
 
 
                pat_src = XVECEXP (pat_src, 0, 0);
                pat_src = XVECEXP (pat_src, 0, 0);
                gcc_assert (GET_CODE (pat_src) == UNSPEC);
                gcc_assert (GET_CODE (pat_src) == UNSPEC);
                gcc_assert (XINT (pat_src, 1) == UNSPEC_FNSTSW);
                gcc_assert (XINT (pat_src, 1) == UNSPEC_FNSTSW);
                /* Fall through.  */
                /* Fall through.  */
 
 
              case UNSPEC_FNSTSW:
              case UNSPEC_FNSTSW:
                /* Combined fcomp+fnstsw generated for doing well with
                /* Combined fcomp+fnstsw generated for doing well with
                   CSE.  When optimizing this would have been broken
                   CSE.  When optimizing this would have been broken
                   up before now.  */
                   up before now.  */
 
 
                pat_src = XVECEXP (pat_src, 0, 0);
                pat_src = XVECEXP (pat_src, 0, 0);
                gcc_assert (GET_CODE (pat_src) == COMPARE);
                gcc_assert (GET_CODE (pat_src) == COMPARE);
 
 
                compare_for_stack_reg (insn, regstack, pat_src);
                compare_for_stack_reg (insn, regstack, pat_src);
                break;
                break;
 
 
              default:
              default:
                gcc_unreachable ();
                gcc_unreachable ();
              }
              }
            break;
            break;
 
 
          case IF_THEN_ELSE:
          case IF_THEN_ELSE:
            /* This insn requires the top of stack to be the destination.  */
            /* This insn requires the top of stack to be the destination.  */
 
 
            src1 = get_true_reg (&XEXP (pat_src, 1));
            src1 = get_true_reg (&XEXP (pat_src, 1));
            src2 = get_true_reg (&XEXP (pat_src, 2));
            src2 = get_true_reg (&XEXP (pat_src, 2));
 
 
            src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
            src1_note = find_regno_note (insn, REG_DEAD, REGNO (*src1));
            src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
            src2_note = find_regno_note (insn, REG_DEAD, REGNO (*src2));
 
 
            /* If the comparison operator is an FP comparison operator,
            /* If the comparison operator is an FP comparison operator,
               it is handled correctly by compare_for_stack_reg () who
               it is handled correctly by compare_for_stack_reg () who
               will move the destination to the top of stack. But if the
               will move the destination to the top of stack. But if the
               comparison operator is not an FP comparison operator, we
               comparison operator is not an FP comparison operator, we
               have to handle it here.  */
               have to handle it here.  */
            if (get_hard_regnum (regstack, *dest) >= FIRST_STACK_REG
            if (get_hard_regnum (regstack, *dest) >= FIRST_STACK_REG
                && REGNO (*dest) != regstack->reg[regstack->top])
                && REGNO (*dest) != regstack->reg[regstack->top])
              {
              {
                /* In case one of operands is the top of stack and the operands
                /* In case one of operands is the top of stack and the operands
                   dies, it is safe to make it the destination operand by
                   dies, it is safe to make it the destination operand by
                   reversing the direction of cmove and avoid fxch.  */
                   reversing the direction of cmove and avoid fxch.  */
                if ((REGNO (*src1) == regstack->reg[regstack->top]
                if ((REGNO (*src1) == regstack->reg[regstack->top]
                     && src1_note)
                     && src1_note)
                    || (REGNO (*src2) == regstack->reg[regstack->top]
                    || (REGNO (*src2) == regstack->reg[regstack->top]
                        && src2_note))
                        && src2_note))
                  {
                  {
                    int idx1 = (get_hard_regnum (regstack, *src1)
                    int idx1 = (get_hard_regnum (regstack, *src1)
                                - FIRST_STACK_REG);
                                - FIRST_STACK_REG);
                    int idx2 = (get_hard_regnum (regstack, *src2)
                    int idx2 = (get_hard_regnum (regstack, *src2)
                                - FIRST_STACK_REG);
                                - FIRST_STACK_REG);
 
 
                    /* Make reg-stack believe that the operands are already
                    /* Make reg-stack believe that the operands are already
                       swapped on the stack */
                       swapped on the stack */
                    regstack->reg[regstack->top - idx1] = REGNO (*src2);
                    regstack->reg[regstack->top - idx1] = REGNO (*src2);
                    regstack->reg[regstack->top - idx2] = REGNO (*src1);
                    regstack->reg[regstack->top - idx2] = REGNO (*src1);
 
 
                    /* Reverse condition to compensate the operand swap.
                    /* Reverse condition to compensate the operand swap.
                       i386 do have comparison always reversible.  */
                       i386 do have comparison always reversible.  */
                    PUT_CODE (XEXP (pat_src, 0),
                    PUT_CODE (XEXP (pat_src, 0),
                              reversed_comparison_code (XEXP (pat_src, 0), insn));
                              reversed_comparison_code (XEXP (pat_src, 0), insn));
                  }
                  }
                else
                else
                  emit_swap_insn (insn, regstack, *dest);
                  emit_swap_insn (insn, regstack, *dest);
              }
              }
 
 
            {
            {
              rtx src_note [3];
              rtx src_note [3];
              int i;
              int i;
 
 
              src_note[0] = 0;
              src_note[0] = 0;
              src_note[1] = src1_note;
              src_note[1] = src1_note;
              src_note[2] = src2_note;
              src_note[2] = src2_note;
 
 
              if (STACK_REG_P (*src1))
              if (STACK_REG_P (*src1))
                replace_reg (src1, get_hard_regnum (regstack, *src1));
                replace_reg (src1, get_hard_regnum (regstack, *src1));
              if (STACK_REG_P (*src2))
              if (STACK_REG_P (*src2))
                replace_reg (src2, get_hard_regnum (regstack, *src2));
                replace_reg (src2, get_hard_regnum (regstack, *src2));
 
 
              for (i = 1; i <= 2; i++)
              for (i = 1; i <= 2; i++)
                if (src_note [i])
                if (src_note [i])
                  {
                  {
                    int regno = REGNO (XEXP (src_note[i], 0));
                    int regno = REGNO (XEXP (src_note[i], 0));
 
 
                    /* If the register that dies is not at the top of
                    /* If the register that dies is not at the top of
                       stack, then move the top of stack to the dead reg.
                       stack, then move the top of stack to the dead reg.
                       Top of stack should never die, as it is the
                       Top of stack should never die, as it is the
                       destination.  */
                       destination.  */
                    gcc_assert (regno != regstack->reg[regstack->top]);
                    gcc_assert (regno != regstack->reg[regstack->top]);
                    remove_regno_note (insn, REG_DEAD, regno);
                    remove_regno_note (insn, REG_DEAD, regno);
                    emit_pop_insn (insn, regstack, XEXP (src_note[i], 0),
                    emit_pop_insn (insn, regstack, XEXP (src_note[i], 0),
                                    EMIT_AFTER);
                                    EMIT_AFTER);
                  }
                  }
            }
            }
 
 
            /* Make dest the top of stack.  Add dest to regstack if
            /* Make dest the top of stack.  Add dest to regstack if
               not present.  */
               not present.  */
            if (get_hard_regnum (regstack, *dest) < FIRST_STACK_REG)
            if (get_hard_regnum (regstack, *dest) < FIRST_STACK_REG)
              regstack->reg[++regstack->top] = REGNO (*dest);
              regstack->reg[++regstack->top] = REGNO (*dest);
            SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
            SET_HARD_REG_BIT (regstack->reg_set, REGNO (*dest));
            replace_reg (dest, FIRST_STACK_REG);
            replace_reg (dest, FIRST_STACK_REG);
            break;
            break;
 
 
          default:
          default:
            gcc_unreachable ();
            gcc_unreachable ();
          }
          }
        break;
        break;
      }
      }
 
 
    default:
    default:
      break;
      break;
    }
    }
 
 
  return control_flow_insn_deleted;
  return control_flow_insn_deleted;
}
}


/* Substitute hard regnums for any stack regs in INSN, which has
/* Substitute hard regnums for any stack regs in INSN, which has
   N_INPUTS inputs and N_OUTPUTS outputs.  REGSTACK is the stack info
   N_INPUTS inputs and N_OUTPUTS outputs.  REGSTACK is the stack info
   before the insn, and is updated with changes made here.
   before the insn, and is updated with changes made here.
 
 
   There are several requirements and assumptions about the use of
   There are several requirements and assumptions about the use of
   stack-like regs in asm statements.  These rules are enforced by
   stack-like regs in asm statements.  These rules are enforced by
   record_asm_stack_regs; see comments there for details.  Any
   record_asm_stack_regs; see comments there for details.  Any
   asm_operands left in the RTL at this point may be assume to meet the
   asm_operands left in the RTL at this point may be assume to meet the
   requirements, since record_asm_stack_regs removes any problem asm.  */
   requirements, since record_asm_stack_regs removes any problem asm.  */
 
 
static void
static void
subst_asm_stack_regs (rtx insn, stack regstack)
subst_asm_stack_regs (rtx insn, stack regstack)
{
{
  rtx body = PATTERN (insn);
  rtx body = PATTERN (insn);
  int alt;
  int alt;
 
 
  rtx *note_reg;                /* Array of note contents */
  rtx *note_reg;                /* Array of note contents */
  rtx **note_loc;               /* Address of REG field of each note */
  rtx **note_loc;               /* Address of REG field of each note */
  enum reg_note *note_kind;     /* The type of each note */
  enum reg_note *note_kind;     /* The type of each note */
 
 
  rtx *clobber_reg = 0;
  rtx *clobber_reg = 0;
  rtx **clobber_loc = 0;
  rtx **clobber_loc = 0;
 
 
  struct stack_def temp_stack;
  struct stack_def temp_stack;
  int n_notes;
  int n_notes;
  int n_clobbers;
  int n_clobbers;
  rtx note;
  rtx note;
  int i;
  int i;
  int n_inputs, n_outputs;
  int n_inputs, n_outputs;
 
 
  if (! check_asm_stack_operands (insn))
  if (! check_asm_stack_operands (insn))
    return;
    return;
 
 
  /* Find out what the constraints required.  If no constraint
  /* Find out what the constraints required.  If no constraint
     alternative matches, that is a compiler bug: we should have caught
     alternative matches, that is a compiler bug: we should have caught
     such an insn in check_asm_stack_operands.  */
     such an insn in check_asm_stack_operands.  */
  extract_insn (insn);
  extract_insn (insn);
  constrain_operands (1);
  constrain_operands (1);
  alt = which_alternative;
  alt = which_alternative;
 
 
  preprocess_constraints ();
  preprocess_constraints ();
 
 
  n_inputs = get_asm_operand_n_inputs (body);
  n_inputs = get_asm_operand_n_inputs (body);
  n_outputs = recog_data.n_operands - n_inputs;
  n_outputs = recog_data.n_operands - n_inputs;
 
 
  gcc_assert (alt >= 0);
  gcc_assert (alt >= 0);
 
 
  /* Strip SUBREGs here to make the following code simpler.  */
  /* Strip SUBREGs here to make the following code simpler.  */
  for (i = 0; i < recog_data.n_operands; i++)
  for (i = 0; i < recog_data.n_operands; i++)
    if (GET_CODE (recog_data.operand[i]) == SUBREG
    if (GET_CODE (recog_data.operand[i]) == SUBREG
        && REG_P (SUBREG_REG (recog_data.operand[i])))
        && REG_P (SUBREG_REG (recog_data.operand[i])))
      {
      {
        recog_data.operand_loc[i] = & SUBREG_REG (recog_data.operand[i]);
        recog_data.operand_loc[i] = & SUBREG_REG (recog_data.operand[i]);
        recog_data.operand[i] = SUBREG_REG (recog_data.operand[i]);
        recog_data.operand[i] = SUBREG_REG (recog_data.operand[i]);
      }
      }
 
 
  /* Set up NOTE_REG, NOTE_LOC and NOTE_KIND.  */
  /* Set up NOTE_REG, NOTE_LOC and NOTE_KIND.  */
 
 
  for (i = 0, note = REG_NOTES (insn); note; note = XEXP (note, 1))
  for (i = 0, note = REG_NOTES (insn); note; note = XEXP (note, 1))
    i++;
    i++;
 
 
  note_reg = alloca (i * sizeof (rtx));
  note_reg = alloca (i * sizeof (rtx));
  note_loc = alloca (i * sizeof (rtx *));
  note_loc = alloca (i * sizeof (rtx *));
  note_kind = alloca (i * sizeof (enum reg_note));
  note_kind = alloca (i * sizeof (enum reg_note));
 
 
  n_notes = 0;
  n_notes = 0;
  for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
  for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
    {
    {
      rtx reg = XEXP (note, 0);
      rtx reg = XEXP (note, 0);
      rtx *loc = & XEXP (note, 0);
      rtx *loc = & XEXP (note, 0);
 
 
      if (GET_CODE (reg) == SUBREG && REG_P (SUBREG_REG (reg)))
      if (GET_CODE (reg) == SUBREG && REG_P (SUBREG_REG (reg)))
        {
        {
          loc = & SUBREG_REG (reg);
          loc = & SUBREG_REG (reg);
          reg = SUBREG_REG (reg);
          reg = SUBREG_REG (reg);
        }
        }
 
 
      if (STACK_REG_P (reg)
      if (STACK_REG_P (reg)
          && (REG_NOTE_KIND (note) == REG_DEAD
          && (REG_NOTE_KIND (note) == REG_DEAD
              || REG_NOTE_KIND (note) == REG_UNUSED))
              || REG_NOTE_KIND (note) == REG_UNUSED))
        {
        {
          note_reg[n_notes] = reg;
          note_reg[n_notes] = reg;
          note_loc[n_notes] = loc;
          note_loc[n_notes] = loc;
          note_kind[n_notes] = REG_NOTE_KIND (note);
          note_kind[n_notes] = REG_NOTE_KIND (note);
          n_notes++;
          n_notes++;
        }
        }
    }
    }
 
 
  /* Set up CLOBBER_REG and CLOBBER_LOC.  */
  /* Set up CLOBBER_REG and CLOBBER_LOC.  */
 
 
  n_clobbers = 0;
  n_clobbers = 0;
 
 
  if (GET_CODE (body) == PARALLEL)
  if (GET_CODE (body) == PARALLEL)
    {
    {
      clobber_reg = alloca (XVECLEN (body, 0) * sizeof (rtx));
      clobber_reg = alloca (XVECLEN (body, 0) * sizeof (rtx));
      clobber_loc = alloca (XVECLEN (body, 0) * sizeof (rtx *));
      clobber_loc = alloca (XVECLEN (body, 0) * sizeof (rtx *));
 
 
      for (i = 0; i < XVECLEN (body, 0); i++)
      for (i = 0; i < XVECLEN (body, 0); i++)
        if (GET_CODE (XVECEXP (body, 0, i)) == CLOBBER)
        if (GET_CODE (XVECEXP (body, 0, i)) == CLOBBER)
          {
          {
            rtx clobber = XVECEXP (body, 0, i);
            rtx clobber = XVECEXP (body, 0, i);
            rtx reg = XEXP (clobber, 0);
            rtx reg = XEXP (clobber, 0);
            rtx *loc = & XEXP (clobber, 0);
            rtx *loc = & XEXP (clobber, 0);
 
 
            if (GET_CODE (reg) == SUBREG && REG_P (SUBREG_REG (reg)))
            if (GET_CODE (reg) == SUBREG && REG_P (SUBREG_REG (reg)))
              {
              {
                loc = & SUBREG_REG (reg);
                loc = & SUBREG_REG (reg);
                reg = SUBREG_REG (reg);
                reg = SUBREG_REG (reg);
              }
              }
 
 
            if (STACK_REG_P (reg))
            if (STACK_REG_P (reg))
              {
              {
                clobber_reg[n_clobbers] = reg;
                clobber_reg[n_clobbers] = reg;
                clobber_loc[n_clobbers] = loc;
                clobber_loc[n_clobbers] = loc;
                n_clobbers++;
                n_clobbers++;
              }
              }
          }
          }
    }
    }
 
 
  temp_stack = *regstack;
  temp_stack = *regstack;
 
 
  /* Put the input regs into the desired place in TEMP_STACK.  */
  /* Put the input regs into the desired place in TEMP_STACK.  */
 
 
  for (i = n_outputs; i < n_outputs + n_inputs; i++)
  for (i = n_outputs; i < n_outputs + n_inputs; i++)
    if (STACK_REG_P (recog_data.operand[i])
    if (STACK_REG_P (recog_data.operand[i])
        && reg_class_subset_p (recog_op_alt[i][alt].cl,
        && reg_class_subset_p (recog_op_alt[i][alt].cl,
                               FLOAT_REGS)
                               FLOAT_REGS)
        && recog_op_alt[i][alt].cl != FLOAT_REGS)
        && recog_op_alt[i][alt].cl != FLOAT_REGS)
      {
      {
        /* If an operand needs to be in a particular reg in
        /* If an operand needs to be in a particular reg in
           FLOAT_REGS, the constraint was either 't' or 'u'.  Since
           FLOAT_REGS, the constraint was either 't' or 'u'.  Since
           these constraints are for single register classes, and
           these constraints are for single register classes, and
           reload guaranteed that operand[i] is already in that class,
           reload guaranteed that operand[i] is already in that class,
           we can just use REGNO (recog_data.operand[i]) to know which
           we can just use REGNO (recog_data.operand[i]) to know which
           actual reg this operand needs to be in.  */
           actual reg this operand needs to be in.  */
 
 
        int regno = get_hard_regnum (&temp_stack, recog_data.operand[i]);
        int regno = get_hard_regnum (&temp_stack, recog_data.operand[i]);
 
 
        gcc_assert (regno >= 0);
        gcc_assert (regno >= 0);
 
 
        if ((unsigned int) regno != REGNO (recog_data.operand[i]))
        if ((unsigned int) regno != REGNO (recog_data.operand[i]))
          {
          {
            /* recog_data.operand[i] is not in the right place.  Find
            /* recog_data.operand[i] is not in the right place.  Find
               it and swap it with whatever is already in I's place.
               it and swap it with whatever is already in I's place.
               K is where recog_data.operand[i] is now.  J is where it
               K is where recog_data.operand[i] is now.  J is where it
               should be.  */
               should be.  */
            int j, k, temp;
            int j, k, temp;
 
 
            k = temp_stack.top - (regno - FIRST_STACK_REG);
            k = temp_stack.top - (regno - FIRST_STACK_REG);
            j = (temp_stack.top
            j = (temp_stack.top
                 - (REGNO (recog_data.operand[i]) - FIRST_STACK_REG));
                 - (REGNO (recog_data.operand[i]) - FIRST_STACK_REG));
 
 
            temp = temp_stack.reg[k];
            temp = temp_stack.reg[k];
            temp_stack.reg[k] = temp_stack.reg[j];
            temp_stack.reg[k] = temp_stack.reg[j];
            temp_stack.reg[j] = temp;
            temp_stack.reg[j] = temp;
          }
          }
      }
      }
 
 
  /* Emit insns before INSN to make sure the reg-stack is in the right
  /* Emit insns before INSN to make sure the reg-stack is in the right
     order.  */
     order.  */
 
 
  change_stack (insn, regstack, &temp_stack, EMIT_BEFORE);
  change_stack (insn, regstack, &temp_stack, EMIT_BEFORE);
 
 
  /* Make the needed input register substitutions.  Do death notes and
  /* Make the needed input register substitutions.  Do death notes and
     clobbers too, because these are for inputs, not outputs.  */
     clobbers too, because these are for inputs, not outputs.  */
 
 
  for (i = n_outputs; i < n_outputs + n_inputs; i++)
  for (i = n_outputs; i < n_outputs + n_inputs; i++)
    if (STACK_REG_P (recog_data.operand[i]))
    if (STACK_REG_P (recog_data.operand[i]))
      {
      {
        int regnum = get_hard_regnum (regstack, recog_data.operand[i]);
        int regnum = get_hard_regnum (regstack, recog_data.operand[i]);
 
 
        gcc_assert (regnum >= 0);
        gcc_assert (regnum >= 0);
 
 
        replace_reg (recog_data.operand_loc[i], regnum);
        replace_reg (recog_data.operand_loc[i], regnum);
      }
      }
 
 
  for (i = 0; i < n_notes; i++)
  for (i = 0; i < n_notes; i++)
    if (note_kind[i] == REG_DEAD)
    if (note_kind[i] == REG_DEAD)
      {
      {
        int regnum = get_hard_regnum (regstack, note_reg[i]);
        int regnum = get_hard_regnum (regstack, note_reg[i]);
 
 
        gcc_assert (regnum >= 0);
        gcc_assert (regnum >= 0);
 
 
        replace_reg (note_loc[i], regnum);
        replace_reg (note_loc[i], regnum);
      }
      }
 
 
  for (i = 0; i < n_clobbers; i++)
  for (i = 0; i < n_clobbers; i++)
    {
    {
      /* It's OK for a CLOBBER to reference a reg that is not live.
      /* It's OK for a CLOBBER to reference a reg that is not live.
         Don't try to replace it in that case.  */
         Don't try to replace it in that case.  */
      int regnum = get_hard_regnum (regstack, clobber_reg[i]);
      int regnum = get_hard_regnum (regstack, clobber_reg[i]);
 
 
      if (regnum >= 0)
      if (regnum >= 0)
        {
        {
          /* Sigh - clobbers always have QImode.  But replace_reg knows
          /* Sigh - clobbers always have QImode.  But replace_reg knows
             that these regs can't be MODE_INT and will assert.  Just put
             that these regs can't be MODE_INT and will assert.  Just put
             the right reg there without calling replace_reg.  */
             the right reg there without calling replace_reg.  */
 
 
          *clobber_loc[i] = FP_MODE_REG (regnum, DFmode);
          *clobber_loc[i] = FP_MODE_REG (regnum, DFmode);
        }
        }
    }
    }
 
 
  /* Now remove from REGSTACK any inputs that the asm implicitly popped.  */
  /* Now remove from REGSTACK any inputs that the asm implicitly popped.  */
 
 
  for (i = n_outputs; i < n_outputs + n_inputs; i++)
  for (i = n_outputs; i < n_outputs + n_inputs; i++)
    if (STACK_REG_P (recog_data.operand[i]))
    if (STACK_REG_P (recog_data.operand[i]))
      {
      {
        /* An input reg is implicitly popped if it is tied to an
        /* An input reg is implicitly popped if it is tied to an
           output, or if there is a CLOBBER for it.  */
           output, or if there is a CLOBBER for it.  */
        int j;
        int j;
 
 
        for (j = 0; j < n_clobbers; j++)
        for (j = 0; j < n_clobbers; j++)
          if (operands_match_p (clobber_reg[j], recog_data.operand[i]))
          if (operands_match_p (clobber_reg[j], recog_data.operand[i]))
            break;
            break;
 
 
        if (j < n_clobbers || recog_op_alt[i][alt].matches >= 0)
        if (j < n_clobbers || recog_op_alt[i][alt].matches >= 0)
          {
          {
            /* recog_data.operand[i] might not be at the top of stack.
            /* recog_data.operand[i] might not be at the top of stack.
               But that's OK, because all we need to do is pop the
               But that's OK, because all we need to do is pop the
               right number of regs off of the top of the reg-stack.
               right number of regs off of the top of the reg-stack.
               record_asm_stack_regs guaranteed that all implicitly
               record_asm_stack_regs guaranteed that all implicitly
               popped regs were grouped at the top of the reg-stack.  */
               popped regs were grouped at the top of the reg-stack.  */
 
 
            CLEAR_HARD_REG_BIT (regstack->reg_set,
            CLEAR_HARD_REG_BIT (regstack->reg_set,
                                regstack->reg[regstack->top]);
                                regstack->reg[regstack->top]);
            regstack->top--;
            regstack->top--;
          }
          }
      }
      }
 
 
  /* Now add to REGSTACK any outputs that the asm implicitly pushed.
  /* Now add to REGSTACK any outputs that the asm implicitly pushed.
     Note that there isn't any need to substitute register numbers.
     Note that there isn't any need to substitute register numbers.
     ???  Explain why this is true.  */
     ???  Explain why this is true.  */
 
 
  for (i = LAST_STACK_REG; i >= FIRST_STACK_REG; i--)
  for (i = LAST_STACK_REG; i >= FIRST_STACK_REG; i--)
    {
    {
      /* See if there is an output for this hard reg.  */
      /* See if there is an output for this hard reg.  */
      int j;
      int j;
 
 
      for (j = 0; j < n_outputs; j++)
      for (j = 0; j < n_outputs; j++)
        if (STACK_REG_P (recog_data.operand[j])
        if (STACK_REG_P (recog_data.operand[j])
            && REGNO (recog_data.operand[j]) == (unsigned) i)
            && REGNO (recog_data.operand[j]) == (unsigned) i)
          {
          {
            regstack->reg[++regstack->top] = i;
            regstack->reg[++regstack->top] = i;
            SET_HARD_REG_BIT (regstack->reg_set, i);
            SET_HARD_REG_BIT (regstack->reg_set, i);
            break;
            break;
          }
          }
    }
    }
 
 
  /* Now emit a pop insn for any REG_UNUSED output, or any REG_DEAD
  /* Now emit a pop insn for any REG_UNUSED output, or any REG_DEAD
     input that the asm didn't implicitly pop.  If the asm didn't
     input that the asm didn't implicitly pop.  If the asm didn't
     implicitly pop an input reg, that reg will still be live.
     implicitly pop an input reg, that reg will still be live.
 
 
     Note that we can't use find_regno_note here: the register numbers
     Note that we can't use find_regno_note here: the register numbers
     in the death notes have already been substituted.  */
     in the death notes have already been substituted.  */
 
 
  for (i = 0; i < n_outputs; i++)
  for (i = 0; i < n_outputs; i++)
    if (STACK_REG_P (recog_data.operand[i]))
    if (STACK_REG_P (recog_data.operand[i]))
      {
      {
        int j;
        int j;
 
 
        for (j = 0; j < n_notes; j++)
        for (j = 0; j < n_notes; j++)
          if (REGNO (recog_data.operand[i]) == REGNO (note_reg[j])
          if (REGNO (recog_data.operand[i]) == REGNO (note_reg[j])
              && note_kind[j] == REG_UNUSED)
              && note_kind[j] == REG_UNUSED)
            {
            {
              insn = emit_pop_insn (insn, regstack, recog_data.operand[i],
              insn = emit_pop_insn (insn, regstack, recog_data.operand[i],
                                    EMIT_AFTER);
                                    EMIT_AFTER);
              break;
              break;
            }
            }
      }
      }
 
 
  for (i = n_outputs; i < n_outputs + n_inputs; i++)
  for (i = n_outputs; i < n_outputs + n_inputs; i++)
    if (STACK_REG_P (recog_data.operand[i]))
    if (STACK_REG_P (recog_data.operand[i]))
      {
      {
        int j;
        int j;
 
 
        for (j = 0; j < n_notes; j++)
        for (j = 0; j < n_notes; j++)
          if (REGNO (recog_data.operand[i]) == REGNO (note_reg[j])
          if (REGNO (recog_data.operand[i]) == REGNO (note_reg[j])
              && note_kind[j] == REG_DEAD
              && note_kind[j] == REG_DEAD
              && TEST_HARD_REG_BIT (regstack->reg_set,
              && TEST_HARD_REG_BIT (regstack->reg_set,
                                    REGNO (recog_data.operand[i])))
                                    REGNO (recog_data.operand[i])))
            {
            {
              insn = emit_pop_insn (insn, regstack, recog_data.operand[i],
              insn = emit_pop_insn (insn, regstack, recog_data.operand[i],
                                    EMIT_AFTER);
                                    EMIT_AFTER);
              break;
              break;
            }
            }
      }
      }
}
}


/* Substitute stack hard reg numbers for stack virtual registers in
/* Substitute stack hard reg numbers for stack virtual registers in
   INSN.  Non-stack register numbers are not changed.  REGSTACK is the
   INSN.  Non-stack register numbers are not changed.  REGSTACK is the
   current stack content.  Insns may be emitted as needed to arrange the
   current stack content.  Insns may be emitted as needed to arrange the
   stack for the 387 based on the contents of the insn.  Return whether
   stack for the 387 based on the contents of the insn.  Return whether
   a control flow insn was deleted in the process.  */
   a control flow insn was deleted in the process.  */
 
 
static bool
static bool
subst_stack_regs (rtx insn, stack regstack)
subst_stack_regs (rtx insn, stack regstack)
{
{
  rtx *note_link, note;
  rtx *note_link, note;
  bool control_flow_insn_deleted = false;
  bool control_flow_insn_deleted = false;
  int i;
  int i;
 
 
  if (CALL_P (insn))
  if (CALL_P (insn))
    {
    {
      int top = regstack->top;
      int top = regstack->top;
 
 
      /* If there are any floating point parameters to be passed in
      /* If there are any floating point parameters to be passed in
         registers for this call, make sure they are in the right
         registers for this call, make sure they are in the right
         order.  */
         order.  */
 
 
      if (top >= 0)
      if (top >= 0)
        {
        {
          straighten_stack (insn, regstack);
          straighten_stack (insn, regstack);
 
 
          /* Now mark the arguments as dead after the call.  */
          /* Now mark the arguments as dead after the call.  */
 
 
          while (regstack->top >= 0)
          while (regstack->top >= 0)
            {
            {
              CLEAR_HARD_REG_BIT (regstack->reg_set, FIRST_STACK_REG + regstack->top);
              CLEAR_HARD_REG_BIT (regstack->reg_set, FIRST_STACK_REG + regstack->top);
              regstack->top--;
              regstack->top--;
            }
            }
        }
        }
    }
    }
 
 
  /* Do the actual substitution if any stack regs are mentioned.
  /* Do the actual substitution if any stack regs are mentioned.
     Since we only record whether entire insn mentions stack regs, and
     Since we only record whether entire insn mentions stack regs, and
     subst_stack_regs_pat only works for patterns that contain stack regs,
     subst_stack_regs_pat only works for patterns that contain stack regs,
     we must check each pattern in a parallel here.  A call_value_pop could
     we must check each pattern in a parallel here.  A call_value_pop could
     fail otherwise.  */
     fail otherwise.  */
 
 
  if (stack_regs_mentioned (insn))
  if (stack_regs_mentioned (insn))
    {
    {
      int n_operands = asm_noperands (PATTERN (insn));
      int n_operands = asm_noperands (PATTERN (insn));
      if (n_operands >= 0)
      if (n_operands >= 0)
        {
        {
          /* This insn is an `asm' with operands.  Decode the operands,
          /* This insn is an `asm' with operands.  Decode the operands,
             decide how many are inputs, and do register substitution.
             decide how many are inputs, and do register substitution.
             Any REG_UNUSED notes will be handled by subst_asm_stack_regs.  */
             Any REG_UNUSED notes will be handled by subst_asm_stack_regs.  */
 
 
          subst_asm_stack_regs (insn, regstack);
          subst_asm_stack_regs (insn, regstack);
          return control_flow_insn_deleted;
          return control_flow_insn_deleted;
        }
        }
 
 
      if (GET_CODE (PATTERN (insn)) == PARALLEL)
      if (GET_CODE (PATTERN (insn)) == PARALLEL)
        for (i = 0; i < XVECLEN (PATTERN (insn), 0); i++)
        for (i = 0; i < XVECLEN (PATTERN (insn), 0); i++)
          {
          {
            if (stack_regs_mentioned_p (XVECEXP (PATTERN (insn), 0, i)))
            if (stack_regs_mentioned_p (XVECEXP (PATTERN (insn), 0, i)))
              {
              {
                if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == CLOBBER)
                if (GET_CODE (XVECEXP (PATTERN (insn), 0, i)) == CLOBBER)
                   XVECEXP (PATTERN (insn), 0, i)
                   XVECEXP (PATTERN (insn), 0, i)
                     = shallow_copy_rtx (XVECEXP (PATTERN (insn), 0, i));
                     = shallow_copy_rtx (XVECEXP (PATTERN (insn), 0, i));
                control_flow_insn_deleted
                control_flow_insn_deleted
                  |= subst_stack_regs_pat (insn, regstack,
                  |= subst_stack_regs_pat (insn, regstack,
                                           XVECEXP (PATTERN (insn), 0, i));
                                           XVECEXP (PATTERN (insn), 0, i));
              }
              }
          }
          }
      else
      else
        control_flow_insn_deleted
        control_flow_insn_deleted
          |= subst_stack_regs_pat (insn, regstack, PATTERN (insn));
          |= subst_stack_regs_pat (insn, regstack, PATTERN (insn));
    }
    }
 
 
  /* subst_stack_regs_pat may have deleted a no-op insn.  If so, any
  /* subst_stack_regs_pat may have deleted a no-op insn.  If so, any
     REG_UNUSED will already have been dealt with, so just return.  */
     REG_UNUSED will already have been dealt with, so just return.  */
 
 
  if (NOTE_P (insn) || INSN_DELETED_P (insn))
  if (NOTE_P (insn) || INSN_DELETED_P (insn))
    return control_flow_insn_deleted;
    return control_flow_insn_deleted;
 
 
  /* If this a noreturn call, we can't insert pop insns after it.
  /* If this a noreturn call, we can't insert pop insns after it.
     Instead, reset the stack state to empty.  */
     Instead, reset the stack state to empty.  */
  if (CALL_P (insn)
  if (CALL_P (insn)
      && find_reg_note (insn, REG_NORETURN, NULL))
      && find_reg_note (insn, REG_NORETURN, NULL))
    {
    {
      regstack->top = -1;
      regstack->top = -1;
      CLEAR_HARD_REG_SET (regstack->reg_set);
      CLEAR_HARD_REG_SET (regstack->reg_set);
      return control_flow_insn_deleted;
      return control_flow_insn_deleted;
    }
    }
 
 
  /* If there is a REG_UNUSED note on a stack register on this insn,
  /* If there is a REG_UNUSED note on a stack register on this insn,
     the indicated reg must be popped.  The REG_UNUSED note is removed,
     the indicated reg must be popped.  The REG_UNUSED note is removed,
     since the form of the newly emitted pop insn references the reg,
     since the form of the newly emitted pop insn references the reg,
     making it no longer `unset'.  */
     making it no longer `unset'.  */
 
 
  note_link = &REG_NOTES (insn);
  note_link = &REG_NOTES (insn);
  for (note = *note_link; note; note = XEXP (note, 1))
  for (note = *note_link; note; note = XEXP (note, 1))
    if (REG_NOTE_KIND (note) == REG_UNUSED && STACK_REG_P (XEXP (note, 0)))
    if (REG_NOTE_KIND (note) == REG_UNUSED && STACK_REG_P (XEXP (note, 0)))
      {
      {
        *note_link = XEXP (note, 1);
        *note_link = XEXP (note, 1);
        insn = emit_pop_insn (insn, regstack, XEXP (note, 0), EMIT_AFTER);
        insn = emit_pop_insn (insn, regstack, XEXP (note, 0), EMIT_AFTER);
      }
      }
    else
    else
      note_link = &XEXP (note, 1);
      note_link = &XEXP (note, 1);
 
 
  return control_flow_insn_deleted;
  return control_flow_insn_deleted;
}
}


/* Change the organization of the stack so that it fits a new basic
/* Change the organization of the stack so that it fits a new basic
   block.  Some registers might have to be popped, but there can never be
   block.  Some registers might have to be popped, but there can never be
   a register live in the new block that is not now live.
   a register live in the new block that is not now live.
 
 
   Insert any needed insns before or after INSN, as indicated by
   Insert any needed insns before or after INSN, as indicated by
   WHERE.  OLD is the original stack layout, and NEW is the desired
   WHERE.  OLD is the original stack layout, and NEW is the desired
   form.  OLD is updated to reflect the code emitted, i.e., it will be
   form.  OLD is updated to reflect the code emitted, i.e., it will be
   the same as NEW upon return.
   the same as NEW upon return.
 
 
   This function will not preserve block_end[].  But that information
   This function will not preserve block_end[].  But that information
   is no longer needed once this has executed.  */
   is no longer needed once this has executed.  */
 
 
static void
static void
change_stack (rtx insn, stack old, stack new, enum emit_where where)
change_stack (rtx insn, stack old, stack new, enum emit_where where)
{
{
  int reg;
  int reg;
  int update_end = 0;
  int update_end = 0;
 
 
  /* Stack adjustments for the first insn in a block update the
  /* Stack adjustments for the first insn in a block update the
     current_block's stack_in instead of inserting insns directly.
     current_block's stack_in instead of inserting insns directly.
     compensate_edges will add the necessary code later.  */
     compensate_edges will add the necessary code later.  */
  if (current_block
  if (current_block
      && starting_stack_p
      && starting_stack_p
      && where == EMIT_BEFORE)
      && where == EMIT_BEFORE)
    {
    {
      BLOCK_INFO (current_block)->stack_in = *new;
      BLOCK_INFO (current_block)->stack_in = *new;
      starting_stack_p = false;
      starting_stack_p = false;
      *old = *new;
      *old = *new;
      return;
      return;
    }
    }
 
 
  /* We will be inserting new insns "backwards".  If we are to insert
  /* We will be inserting new insns "backwards".  If we are to insert
     after INSN, find the next insn, and insert before it.  */
     after INSN, find the next insn, and insert before it.  */
 
 
  if (where == EMIT_AFTER)
  if (where == EMIT_AFTER)
    {
    {
      if (current_block && BB_END (current_block) == insn)
      if (current_block && BB_END (current_block) == insn)
        update_end = 1;
        update_end = 1;
      insn = NEXT_INSN (insn);
      insn = NEXT_INSN (insn);
    }
    }
 
 
  /* Pop any registers that are not needed in the new block.  */
  /* Pop any registers that are not needed in the new block.  */
 
 
  /* If the destination block's stack already has a specified layout
  /* If the destination block's stack already has a specified layout
     and contains two or more registers, use a more intelligent algorithm
     and contains two or more registers, use a more intelligent algorithm
     to pop registers that minimizes the number number of fxchs below.  */
     to pop registers that minimizes the number number of fxchs below.  */
  if (new->top > 0)
  if (new->top > 0)
    {
    {
      bool slots[REG_STACK_SIZE];
      bool slots[REG_STACK_SIZE];
      int pops[REG_STACK_SIZE];
      int pops[REG_STACK_SIZE];
      int next, dest, topsrc;
      int next, dest, topsrc;
 
 
      /* First pass to determine the free slots.  */
      /* First pass to determine the free slots.  */
      for (reg = 0; reg <= new->top; reg++)
      for (reg = 0; reg <= new->top; reg++)
        slots[reg] = TEST_HARD_REG_BIT (new->reg_set, old->reg[reg]);
        slots[reg] = TEST_HARD_REG_BIT (new->reg_set, old->reg[reg]);
 
 
      /* Second pass to allocate preferred slots.  */
      /* Second pass to allocate preferred slots.  */
      topsrc = -1;
      topsrc = -1;
      for (reg = old->top; reg > new->top; reg--)
      for (reg = old->top; reg > new->top; reg--)
        if (TEST_HARD_REG_BIT (new->reg_set, old->reg[reg]))
        if (TEST_HARD_REG_BIT (new->reg_set, old->reg[reg]))
          {
          {
            dest = -1;
            dest = -1;
            for (next = 0; next <= new->top; next++)
            for (next = 0; next <= new->top; next++)
              if (!slots[next] && new->reg[next] == old->reg[reg])
              if (!slots[next] && new->reg[next] == old->reg[reg])
                {
                {
                  /* If this is a preference for the new top of stack, record
                  /* If this is a preference for the new top of stack, record
                     the fact by remembering it's old->reg in topsrc.  */
                     the fact by remembering it's old->reg in topsrc.  */
                  if (next == new->top)
                  if (next == new->top)
                    topsrc = reg;
                    topsrc = reg;
                  slots[next] = true;
                  slots[next] = true;
                  dest = next;
                  dest = next;
                  break;
                  break;
                }
                }
            pops[reg] = dest;
            pops[reg] = dest;
          }
          }
        else
        else
          pops[reg] = reg;
          pops[reg] = reg;
 
 
      /* Intentionally, avoid placing the top of stack in it's correct
      /* Intentionally, avoid placing the top of stack in it's correct
         location, if we still need to permute the stack below and we
         location, if we still need to permute the stack below and we
         can usefully place it somewhere else.  This is the case if any
         can usefully place it somewhere else.  This is the case if any
         slot is still unallocated, in which case we should place the
         slot is still unallocated, in which case we should place the
         top of stack there.  */
         top of stack there.  */
      if (topsrc != -1)
      if (topsrc != -1)
        for (reg = 0; reg < new->top; reg++)
        for (reg = 0; reg < new->top; reg++)
          if (!slots[reg])
          if (!slots[reg])
            {
            {
              pops[topsrc] = reg;
              pops[topsrc] = reg;
              slots[new->top] = false;
              slots[new->top] = false;
              slots[reg] = true;
              slots[reg] = true;
              break;
              break;
            }
            }
 
 
      /* Third pass allocates remaining slots and emits pop insns.  */
      /* Third pass allocates remaining slots and emits pop insns.  */
      next = new->top;
      next = new->top;
      for (reg = old->top; reg > new->top; reg--)
      for (reg = old->top; reg > new->top; reg--)
        {
        {
          dest = pops[reg];
          dest = pops[reg];
          if (dest == -1)
          if (dest == -1)
            {
            {
              /* Find next free slot.  */
              /* Find next free slot.  */
              while (slots[next])
              while (slots[next])
                next--;
                next--;
              dest = next--;
              dest = next--;
            }
            }
          emit_pop_insn (insn, old, FP_MODE_REG (old->reg[dest], DFmode),
          emit_pop_insn (insn, old, FP_MODE_REG (old->reg[dest], DFmode),
                         EMIT_BEFORE);
                         EMIT_BEFORE);
        }
        }
    }
    }
  else
  else
    {
    {
      /* The following loop attempts to maximize the number of times we
      /* The following loop attempts to maximize the number of times we
         pop the top of the stack, as this permits the use of the faster
         pop the top of the stack, as this permits the use of the faster
         ffreep instruction on platforms that support it.  */
         ffreep instruction on platforms that support it.  */
      int live, next;
      int live, next;
 
 
      live = 0;
      live = 0;
      for (reg = 0; reg <= old->top; reg++)
      for (reg = 0; reg <= old->top; reg++)
        if (TEST_HARD_REG_BIT (new->reg_set, old->reg[reg]))
        if (TEST_HARD_REG_BIT (new->reg_set, old->reg[reg]))
          live++;
          live++;
 
 
      next = live;
      next = live;
      while (old->top >= live)
      while (old->top >= live)
        if (TEST_HARD_REG_BIT (new->reg_set, old->reg[old->top]))
        if (TEST_HARD_REG_BIT (new->reg_set, old->reg[old->top]))
          {
          {
            while (TEST_HARD_REG_BIT (new->reg_set, old->reg[next]))
            while (TEST_HARD_REG_BIT (new->reg_set, old->reg[next]))
              next--;
              next--;
            emit_pop_insn (insn, old, FP_MODE_REG (old->reg[next], DFmode),
            emit_pop_insn (insn, old, FP_MODE_REG (old->reg[next], DFmode),
                           EMIT_BEFORE);
                           EMIT_BEFORE);
          }
          }
        else
        else
          emit_pop_insn (insn, old, FP_MODE_REG (old->reg[old->top], DFmode),
          emit_pop_insn (insn, old, FP_MODE_REG (old->reg[old->top], DFmode),
                         EMIT_BEFORE);
                         EMIT_BEFORE);
    }
    }
 
 
  if (new->top == -2)
  if (new->top == -2)
    {
    {
      /* If the new block has never been processed, then it can inherit
      /* If the new block has never been processed, then it can inherit
         the old stack order.  */
         the old stack order.  */
 
 
      new->top = old->top;
      new->top = old->top;
      memcpy (new->reg, old->reg, sizeof (new->reg));
      memcpy (new->reg, old->reg, sizeof (new->reg));
    }
    }
  else
  else
    {
    {
      /* This block has been entered before, and we must match the
      /* This block has been entered before, and we must match the
         previously selected stack order.  */
         previously selected stack order.  */
 
 
      /* By now, the only difference should be the order of the stack,
      /* By now, the only difference should be the order of the stack,
         not their depth or liveliness.  */
         not their depth or liveliness.  */
 
 
      GO_IF_HARD_REG_EQUAL (old->reg_set, new->reg_set, win);
      GO_IF_HARD_REG_EQUAL (old->reg_set, new->reg_set, win);
      gcc_unreachable ();
      gcc_unreachable ();
    win:
    win:
      gcc_assert (old->top == new->top);
      gcc_assert (old->top == new->top);
 
 
      /* If the stack is not empty (new->top != -1), loop here emitting
      /* If the stack is not empty (new->top != -1), loop here emitting
         swaps until the stack is correct.
         swaps until the stack is correct.
 
 
         The worst case number of swaps emitted is N + 2, where N is the
         The worst case number of swaps emitted is N + 2, where N is the
         depth of the stack.  In some cases, the reg at the top of
         depth of the stack.  In some cases, the reg at the top of
         stack may be correct, but swapped anyway in order to fix
         stack may be correct, but swapped anyway in order to fix
         other regs.  But since we never swap any other reg away from
         other regs.  But since we never swap any other reg away from
         its correct slot, this algorithm will converge.  */
         its correct slot, this algorithm will converge.  */
 
 
      if (new->top != -1)
      if (new->top != -1)
        do
        do
          {
          {
            /* Swap the reg at top of stack into the position it is
            /* Swap the reg at top of stack into the position it is
               supposed to be in, until the correct top of stack appears.  */
               supposed to be in, until the correct top of stack appears.  */
 
 
            while (old->reg[old->top] != new->reg[new->top])
            while (old->reg[old->top] != new->reg[new->top])
              {
              {
                for (reg = new->top; reg >= 0; reg--)
                for (reg = new->top; reg >= 0; reg--)
                  if (new->reg[reg] == old->reg[old->top])
                  if (new->reg[reg] == old->reg[old->top])
                    break;
                    break;
 
 
                gcc_assert (reg != -1);
                gcc_assert (reg != -1);
 
 
                emit_swap_insn (insn, old,
                emit_swap_insn (insn, old,
                                FP_MODE_REG (old->reg[reg], DFmode));
                                FP_MODE_REG (old->reg[reg], DFmode));
              }
              }
 
 
            /* See if any regs remain incorrect.  If so, bring an
            /* See if any regs remain incorrect.  If so, bring an
             incorrect reg to the top of stack, and let the while loop
             incorrect reg to the top of stack, and let the while loop
             above fix it.  */
             above fix it.  */
 
 
            for (reg = new->top; reg >= 0; reg--)
            for (reg = new->top; reg >= 0; reg--)
              if (new->reg[reg] != old->reg[reg])
              if (new->reg[reg] != old->reg[reg])
                {
                {
                  emit_swap_insn (insn, old,
                  emit_swap_insn (insn, old,
                                  FP_MODE_REG (old->reg[reg], DFmode));
                                  FP_MODE_REG (old->reg[reg], DFmode));
                  break;
                  break;
                }
                }
          } while (reg >= 0);
          } while (reg >= 0);
 
 
      /* At this point there must be no differences.  */
      /* At this point there must be no differences.  */
 
 
      for (reg = old->top; reg >= 0; reg--)
      for (reg = old->top; reg >= 0; reg--)
        gcc_assert (old->reg[reg] == new->reg[reg]);
        gcc_assert (old->reg[reg] == new->reg[reg]);
    }
    }
 
 
  if (update_end)
  if (update_end)
    BB_END (current_block) = PREV_INSN (insn);
    BB_END (current_block) = PREV_INSN (insn);
}
}


/* Print stack configuration.  */
/* Print stack configuration.  */
 
 
static void
static void
print_stack (FILE *file, stack s)
print_stack (FILE *file, stack s)
{
{
  if (! file)
  if (! file)
    return;
    return;
 
 
  if (s->top == -2)
  if (s->top == -2)
    fprintf (file, "uninitialized\n");
    fprintf (file, "uninitialized\n");
  else if (s->top == -1)
  else if (s->top == -1)
    fprintf (file, "empty\n");
    fprintf (file, "empty\n");
  else
  else
    {
    {
      int i;
      int i;
      fputs ("[ ", file);
      fputs ("[ ", file);
      for (i = 0; i <= s->top; ++i)
      for (i = 0; i <= s->top; ++i)
        fprintf (file, "%d ", s->reg[i]);
        fprintf (file, "%d ", s->reg[i]);
      fputs ("]\n", file);
      fputs ("]\n", file);
    }
    }
}
}


/* This function was doing life analysis.  We now let the regular live
/* This function was doing life analysis.  We now let the regular live
   code do it's job, so we only need to check some extra invariants
   code do it's job, so we only need to check some extra invariants
   that reg-stack expects.  Primary among these being that all registers
   that reg-stack expects.  Primary among these being that all registers
   are initialized before use.
   are initialized before use.
 
 
   The function returns true when code was emitted to CFG edges and
   The function returns true when code was emitted to CFG edges and
   commit_edge_insertions needs to be called.  */
   commit_edge_insertions needs to be called.  */
 
 
static int
static int
convert_regs_entry (void)
convert_regs_entry (void)
{
{
  int inserted = 0;
  int inserted = 0;
  edge e;
  edge e;
  edge_iterator ei;
  edge_iterator ei;
 
 
  /* Load something into each stack register live at function entry.
  /* Load something into each stack register live at function entry.
     Such live registers can be caused by uninitialized variables or
     Such live registers can be caused by uninitialized variables or
     functions not returning values on all paths.  In order to keep
     functions not returning values on all paths.  In order to keep
     the push/pop code happy, and to not scrog the register stack, we
     the push/pop code happy, and to not scrog the register stack, we
     must put something in these registers.  Use a QNaN.
     must put something in these registers.  Use a QNaN.
 
 
     Note that we are inserting converted code here.  This code is
     Note that we are inserting converted code here.  This code is
     never seen by the convert_regs pass.  */
     never seen by the convert_regs pass.  */
 
 
  FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
  FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
    {
    {
      basic_block block = e->dest;
      basic_block block = e->dest;
      block_info bi = BLOCK_INFO (block);
      block_info bi = BLOCK_INFO (block);
      int reg, top = -1;
      int reg, top = -1;
 
 
      for (reg = LAST_STACK_REG; reg >= FIRST_STACK_REG; --reg)
      for (reg = LAST_STACK_REG; reg >= FIRST_STACK_REG; --reg)
        if (TEST_HARD_REG_BIT (bi->stack_in.reg_set, reg))
        if (TEST_HARD_REG_BIT (bi->stack_in.reg_set, reg))
          {
          {
            rtx init;
            rtx init;
 
 
            bi->stack_in.reg[++top] = reg;
            bi->stack_in.reg[++top] = reg;
 
 
            init = gen_rtx_SET (VOIDmode,
            init = gen_rtx_SET (VOIDmode,
                                FP_MODE_REG (FIRST_STACK_REG, SFmode),
                                FP_MODE_REG (FIRST_STACK_REG, SFmode),
                                not_a_num);
                                not_a_num);
            insert_insn_on_edge (init, e);
            insert_insn_on_edge (init, e);
            inserted = 1;
            inserted = 1;
          }
          }
 
 
      bi->stack_in.top = top;
      bi->stack_in.top = top;
    }
    }
 
 
  return inserted;
  return inserted;
}
}
 
 
/* Construct the desired stack for function exit.  This will either
/* Construct the desired stack for function exit.  This will either
   be `empty', or the function return value at top-of-stack.  */
   be `empty', or the function return value at top-of-stack.  */
 
 
static void
static void
convert_regs_exit (void)
convert_regs_exit (void)
{
{
  int value_reg_low, value_reg_high;
  int value_reg_low, value_reg_high;
  stack output_stack;
  stack output_stack;
  rtx retvalue;
  rtx retvalue;
 
 
  retvalue = stack_result (current_function_decl);
  retvalue = stack_result (current_function_decl);
  value_reg_low = value_reg_high = -1;
  value_reg_low = value_reg_high = -1;
  if (retvalue)
  if (retvalue)
    {
    {
      value_reg_low = REGNO (retvalue);
      value_reg_low = REGNO (retvalue);
      value_reg_high = value_reg_low
      value_reg_high = value_reg_low
        + hard_regno_nregs[value_reg_low][GET_MODE (retvalue)] - 1;
        + hard_regno_nregs[value_reg_low][GET_MODE (retvalue)] - 1;
    }
    }
 
 
  output_stack = &BLOCK_INFO (EXIT_BLOCK_PTR)->stack_in;
  output_stack = &BLOCK_INFO (EXIT_BLOCK_PTR)->stack_in;
  if (value_reg_low == -1)
  if (value_reg_low == -1)
    output_stack->top = -1;
    output_stack->top = -1;
  else
  else
    {
    {
      int reg;
      int reg;
 
 
      output_stack->top = value_reg_high - value_reg_low;
      output_stack->top = value_reg_high - value_reg_low;
      for (reg = value_reg_low; reg <= value_reg_high; ++reg)
      for (reg = value_reg_low; reg <= value_reg_high; ++reg)
        {
        {
          output_stack->reg[value_reg_high - reg] = reg;
          output_stack->reg[value_reg_high - reg] = reg;
          SET_HARD_REG_BIT (output_stack->reg_set, reg);
          SET_HARD_REG_BIT (output_stack->reg_set, reg);
        }
        }
    }
    }
}
}
 
 
/* Copy the stack info from the end of edge E's source block to the
/* Copy the stack info from the end of edge E's source block to the
   start of E's destination block.  */
   start of E's destination block.  */
 
 
static void
static void
propagate_stack (edge e)
propagate_stack (edge e)
{
{
  stack src_stack = &BLOCK_INFO (e->src)->stack_out;
  stack src_stack = &BLOCK_INFO (e->src)->stack_out;
  stack dest_stack = &BLOCK_INFO (e->dest)->stack_in;
  stack dest_stack = &BLOCK_INFO (e->dest)->stack_in;
  int reg;
  int reg;
 
 
  /* Preserve the order of the original stack, but check whether
  /* Preserve the order of the original stack, but check whether
     any pops are needed.  */
     any pops are needed.  */
  dest_stack->top = -1;
  dest_stack->top = -1;
  for (reg = 0; reg <= src_stack->top; ++reg)
  for (reg = 0; reg <= src_stack->top; ++reg)
    if (TEST_HARD_REG_BIT (dest_stack->reg_set, src_stack->reg[reg]))
    if (TEST_HARD_REG_BIT (dest_stack->reg_set, src_stack->reg[reg]))
      dest_stack->reg[++dest_stack->top] = src_stack->reg[reg];
      dest_stack->reg[++dest_stack->top] = src_stack->reg[reg];
}
}
 
 
 
 
/* Adjust the stack of edge E's source block on exit to match the stack
/* Adjust the stack of edge E's source block on exit to match the stack
   of it's target block upon input.  The stack layouts of both blocks
   of it's target block upon input.  The stack layouts of both blocks
   should have been defined by now.  */
   should have been defined by now.  */
 
 
static bool
static bool
compensate_edge (edge e)
compensate_edge (edge e)
{
{
  basic_block source = e->src, target = e->dest;
  basic_block source = e->src, target = e->dest;
  stack target_stack = &BLOCK_INFO (target)->stack_in;
  stack target_stack = &BLOCK_INFO (target)->stack_in;
  stack source_stack = &BLOCK_INFO (source)->stack_out;
  stack source_stack = &BLOCK_INFO (source)->stack_out;
  struct stack_def regstack;
  struct stack_def regstack;
  int reg;
  int reg;
 
 
  if (dump_file)
  if (dump_file)
    fprintf (dump_file, "Edge %d->%d: ", source->index, target->index);
    fprintf (dump_file, "Edge %d->%d: ", source->index, target->index);
 
 
  gcc_assert (target_stack->top != -2);
  gcc_assert (target_stack->top != -2);
 
 
  /* Check whether stacks are identical.  */
  /* Check whether stacks are identical.  */
  if (target_stack->top == source_stack->top)
  if (target_stack->top == source_stack->top)
    {
    {
      for (reg = target_stack->top; reg >= 0; --reg)
      for (reg = target_stack->top; reg >= 0; --reg)
        if (target_stack->reg[reg] != source_stack->reg[reg])
        if (target_stack->reg[reg] != source_stack->reg[reg])
          break;
          break;
 
 
      if (reg == -1)
      if (reg == -1)
        {
        {
          if (dump_file)
          if (dump_file)
            fprintf (dump_file, "no changes needed\n");
            fprintf (dump_file, "no changes needed\n");
          return false;
          return false;
        }
        }
    }
    }
 
 
  if (dump_file)
  if (dump_file)
    {
    {
      fprintf (dump_file, "correcting stack to ");
      fprintf (dump_file, "correcting stack to ");
      print_stack (dump_file, target_stack);
      print_stack (dump_file, target_stack);
    }
    }
 
 
  /* Abnormal calls may appear to have values live in st(0), but the
  /* Abnormal calls may appear to have values live in st(0), but the
     abnormal return path will not have actually loaded the values.  */
     abnormal return path will not have actually loaded the values.  */
  if (e->flags & EDGE_ABNORMAL_CALL)
  if (e->flags & EDGE_ABNORMAL_CALL)
    {
    {
      /* Assert that the lifetimes are as we expect -- one value
      /* Assert that the lifetimes are as we expect -- one value
         live at st(0) on the end of the source block, and no
         live at st(0) on the end of the source block, and no
         values live at the beginning of the destination block.
         values live at the beginning of the destination block.
         For complex return values, we may have st(1) live as well.  */
         For complex return values, we may have st(1) live as well.  */
      gcc_assert (source_stack->top == 0 || source_stack->top == 1);
      gcc_assert (source_stack->top == 0 || source_stack->top == 1);
      gcc_assert (target_stack->top == -1);
      gcc_assert (target_stack->top == -1);
      return false;
      return false;
    }
    }
 
 
  /* Handle non-call EH edges specially.  The normal return path have
  /* Handle non-call EH edges specially.  The normal return path have
     values in registers.  These will be popped en masse by the unwind
     values in registers.  These will be popped en masse by the unwind
     library.  */
     library.  */
  if (e->flags & EDGE_EH)
  if (e->flags & EDGE_EH)
    {
    {
      gcc_assert (target_stack->top == -1);
      gcc_assert (target_stack->top == -1);
      return false;
      return false;
    }
    }
 
 
  /* We don't support abnormal edges.  Global takes care to
  /* We don't support abnormal edges.  Global takes care to
     avoid any live register across them, so we should never
     avoid any live register across them, so we should never
     have to insert instructions on such edges.  */
     have to insert instructions on such edges.  */
  gcc_assert (! (e->flags & EDGE_ABNORMAL));
  gcc_assert (! (e->flags & EDGE_ABNORMAL));
 
 
  /* Make a copy of source_stack as change_stack is destructive.  */
  /* Make a copy of source_stack as change_stack is destructive.  */
  regstack = *source_stack;
  regstack = *source_stack;
 
 
  /* It is better to output directly to the end of the block
  /* It is better to output directly to the end of the block
     instead of to the edge, because emit_swap can do minimal
     instead of to the edge, because emit_swap can do minimal
     insn scheduling.  We can do this when there is only one
     insn scheduling.  We can do this when there is only one
     edge out, and it is not abnormal.  */
     edge out, and it is not abnormal.  */
  if (EDGE_COUNT (source->succs) == 1)
  if (EDGE_COUNT (source->succs) == 1)
    {
    {
      current_block = source;
      current_block = source;
      change_stack (BB_END (source), &regstack, target_stack,
      change_stack (BB_END (source), &regstack, target_stack,
                    (JUMP_P (BB_END (source)) ? EMIT_BEFORE : EMIT_AFTER));
                    (JUMP_P (BB_END (source)) ? EMIT_BEFORE : EMIT_AFTER));
    }
    }
  else
  else
    {
    {
      rtx seq, after;
      rtx seq, after;
 
 
      current_block = NULL;
      current_block = NULL;
      start_sequence ();
      start_sequence ();
 
 
      /* ??? change_stack needs some point to emit insns after.  */
      /* ??? change_stack needs some point to emit insns after.  */
      after = emit_note (NOTE_INSN_DELETED);
      after = emit_note (NOTE_INSN_DELETED);
 
 
      change_stack (after, &regstack, target_stack, EMIT_BEFORE);
      change_stack (after, &regstack, target_stack, EMIT_BEFORE);
 
 
      seq = get_insns ();
      seq = get_insns ();
      end_sequence ();
      end_sequence ();
 
 
      insert_insn_on_edge (seq, e);
      insert_insn_on_edge (seq, e);
      return true;
      return true;
    }
    }
  return false;
  return false;
}
}
 
 
/* Traverse all non-entry edges in the CFG, and emit the necessary
/* Traverse all non-entry edges in the CFG, and emit the necessary
   edge compensation code to change the stack from stack_out of the
   edge compensation code to change the stack from stack_out of the
   source block to the stack_in of the destination block.  */
   source block to the stack_in of the destination block.  */
 
 
static bool
static bool
compensate_edges (void)
compensate_edges (void)
{
{
  bool inserted = false;
  bool inserted = false;
  basic_block bb;
  basic_block bb;
 
 
  starting_stack_p = false;
  starting_stack_p = false;
 
 
  FOR_EACH_BB (bb)
  FOR_EACH_BB (bb)
    if (bb != ENTRY_BLOCK_PTR)
    if (bb != ENTRY_BLOCK_PTR)
      {
      {
        edge e;
        edge e;
        edge_iterator ei;
        edge_iterator ei;
 
 
        FOR_EACH_EDGE (e, ei, bb->succs)
        FOR_EACH_EDGE (e, ei, bb->succs)
          inserted |= compensate_edge (e);
          inserted |= compensate_edge (e);
      }
      }
  return inserted;
  return inserted;
}
}
 
 
/* Select the better of two edges E1 and E2 to use to determine the
/* Select the better of two edges E1 and E2 to use to determine the
   stack layout for their shared destination basic block.  This is
   stack layout for their shared destination basic block.  This is
   typically the more frequently executed.  The edge E1 may be NULL
   typically the more frequently executed.  The edge E1 may be NULL
   (in which case E2 is returned), but E2 is always non-NULL.  */
   (in which case E2 is returned), but E2 is always non-NULL.  */
 
 
static edge
static edge
better_edge (edge e1, edge e2)
better_edge (edge e1, edge e2)
{
{
  if (!e1)
  if (!e1)
    return e2;
    return e2;
 
 
  if (EDGE_FREQUENCY (e1) > EDGE_FREQUENCY (e2))
  if (EDGE_FREQUENCY (e1) > EDGE_FREQUENCY (e2))
    return e1;
    return e1;
  if (EDGE_FREQUENCY (e1) < EDGE_FREQUENCY (e2))
  if (EDGE_FREQUENCY (e1) < EDGE_FREQUENCY (e2))
    return e2;
    return e2;
 
 
  if (e1->count > e2->count)
  if (e1->count > e2->count)
    return e1;
    return e1;
  if (e1->count < e2->count)
  if (e1->count < e2->count)
    return e2;
    return e2;
 
 
  /* Prefer critical edges to minimize inserting compensation code on
  /* Prefer critical edges to minimize inserting compensation code on
     critical edges.  */
     critical edges.  */
 
 
  if (EDGE_CRITICAL_P (e1) != EDGE_CRITICAL_P (e2))
  if (EDGE_CRITICAL_P (e1) != EDGE_CRITICAL_P (e2))
    return EDGE_CRITICAL_P (e1) ? e1 : e2;
    return EDGE_CRITICAL_P (e1) ? e1 : e2;
 
 
  /* Avoid non-deterministic behavior.  */
  /* Avoid non-deterministic behavior.  */
  return (e1->src->index < e2->src->index) ? e1 : e2;
  return (e1->src->index < e2->src->index) ? e1 : e2;
}
}
 
 
/* Convert stack register references in one block.  */
/* Convert stack register references in one block.  */
 
 
static void
static void
convert_regs_1 (basic_block block)
convert_regs_1 (basic_block block)
{
{
  struct stack_def regstack;
  struct stack_def regstack;
  block_info bi = BLOCK_INFO (block);
  block_info bi = BLOCK_INFO (block);
  int reg;
  int reg;
  rtx insn, next;
  rtx insn, next;
  bool control_flow_insn_deleted = false;
  bool control_flow_insn_deleted = false;
 
 
  any_malformed_asm = false;
  any_malformed_asm = false;
 
 
  /* Choose an initial stack layout, if one hasn't already been chosen.  */
  /* Choose an initial stack layout, if one hasn't already been chosen.  */
  if (bi->stack_in.top == -2)
  if (bi->stack_in.top == -2)
    {
    {
      edge e, beste = NULL;
      edge e, beste = NULL;
      edge_iterator ei;
      edge_iterator ei;
 
 
      /* Select the best incoming edge (typically the most frequent) to
      /* Select the best incoming edge (typically the most frequent) to
         use as a template for this basic block.  */
         use as a template for this basic block.  */
      FOR_EACH_EDGE (e, ei, block->preds)
      FOR_EACH_EDGE (e, ei, block->preds)
        if (BLOCK_INFO (e->src)->done)
        if (BLOCK_INFO (e->src)->done)
          beste = better_edge (beste, e);
          beste = better_edge (beste, e);
 
 
      if (beste)
      if (beste)
        propagate_stack (beste);
        propagate_stack (beste);
      else
      else
        {
        {
          /* No predecessors.  Create an arbitrary input stack.  */
          /* No predecessors.  Create an arbitrary input stack.  */
          bi->stack_in.top = -1;
          bi->stack_in.top = -1;
          for (reg = LAST_STACK_REG; reg >= FIRST_STACK_REG; --reg)
          for (reg = LAST_STACK_REG; reg >= FIRST_STACK_REG; --reg)
            if (TEST_HARD_REG_BIT (bi->stack_in.reg_set, reg))
            if (TEST_HARD_REG_BIT (bi->stack_in.reg_set, reg))
              bi->stack_in.reg[++bi->stack_in.top] = reg;
              bi->stack_in.reg[++bi->stack_in.top] = reg;
        }
        }
    }
    }
 
 
  if (dump_file)
  if (dump_file)
    {
    {
      fprintf (dump_file, "\nBasic block %d\nInput stack: ", block->index);
      fprintf (dump_file, "\nBasic block %d\nInput stack: ", block->index);
      print_stack (dump_file, &bi->stack_in);
      print_stack (dump_file, &bi->stack_in);
    }
    }
 
 
  /* Process all insns in this block.  Keep track of NEXT so that we
  /* Process all insns in this block.  Keep track of NEXT so that we
     don't process insns emitted while substituting in INSN.  */
     don't process insns emitted while substituting in INSN.  */
  current_block = block;
  current_block = block;
  next = BB_HEAD (block);
  next = BB_HEAD (block);
  regstack = bi->stack_in;
  regstack = bi->stack_in;
  starting_stack_p = true;
  starting_stack_p = true;
 
 
  do
  do
    {
    {
      insn = next;
      insn = next;
      next = NEXT_INSN (insn);
      next = NEXT_INSN (insn);
 
 
      /* Ensure we have not missed a block boundary.  */
      /* Ensure we have not missed a block boundary.  */
      gcc_assert (next);
      gcc_assert (next);
      if (insn == BB_END (block))
      if (insn == BB_END (block))
        next = NULL;
        next = NULL;
 
 
      /* Don't bother processing unless there is a stack reg
      /* Don't bother processing unless there is a stack reg
         mentioned or if it's a CALL_INSN.  */
         mentioned or if it's a CALL_INSN.  */
      if (stack_regs_mentioned (insn)
      if (stack_regs_mentioned (insn)
          || CALL_P (insn))
          || CALL_P (insn))
        {
        {
          if (dump_file)
          if (dump_file)
            {
            {
              fprintf (dump_file, "  insn %d input stack: ",
              fprintf (dump_file, "  insn %d input stack: ",
                       INSN_UID (insn));
                       INSN_UID (insn));
              print_stack (dump_file, &regstack);
              print_stack (dump_file, &regstack);
            }
            }
          control_flow_insn_deleted |= subst_stack_regs (insn, &regstack);
          control_flow_insn_deleted |= subst_stack_regs (insn, &regstack);
          starting_stack_p = false;
          starting_stack_p = false;
        }
        }
    }
    }
  while (next);
  while (next);
 
 
  if (dump_file)
  if (dump_file)
    {
    {
      fprintf (dump_file, "Expected live registers [");
      fprintf (dump_file, "Expected live registers [");
      for (reg = FIRST_STACK_REG; reg <= LAST_STACK_REG; ++reg)
      for (reg = FIRST_STACK_REG; reg <= LAST_STACK_REG; ++reg)
        if (TEST_HARD_REG_BIT (bi->out_reg_set, reg))
        if (TEST_HARD_REG_BIT (bi->out_reg_set, reg))
          fprintf (dump_file, " %d", reg);
          fprintf (dump_file, " %d", reg);
      fprintf (dump_file, " ]\nOutput stack: ");
      fprintf (dump_file, " ]\nOutput stack: ");
      print_stack (dump_file, &regstack);
      print_stack (dump_file, &regstack);
    }
    }
 
 
  insn = BB_END (block);
  insn = BB_END (block);
  if (JUMP_P (insn))
  if (JUMP_P (insn))
    insn = PREV_INSN (insn);
    insn = PREV_INSN (insn);
 
 
  /* If the function is declared to return a value, but it returns one
  /* If the function is declared to return a value, but it returns one
     in only some cases, some registers might come live here.  Emit
     in only some cases, some registers might come live here.  Emit
     necessary moves for them.  */
     necessary moves for them.  */
 
 
  for (reg = FIRST_STACK_REG; reg <= LAST_STACK_REG; ++reg)
  for (reg = FIRST_STACK_REG; reg <= LAST_STACK_REG; ++reg)
    {
    {
      if (TEST_HARD_REG_BIT (bi->out_reg_set, reg)
      if (TEST_HARD_REG_BIT (bi->out_reg_set, reg)
          && ! TEST_HARD_REG_BIT (regstack.reg_set, reg))
          && ! TEST_HARD_REG_BIT (regstack.reg_set, reg))
        {
        {
          rtx set;
          rtx set;
 
 
          if (dump_file)
          if (dump_file)
            fprintf (dump_file, "Emitting insn initializing reg %d\n", reg);
            fprintf (dump_file, "Emitting insn initializing reg %d\n", reg);
 
 
          set = gen_rtx_SET (VOIDmode, FP_MODE_REG (reg, SFmode), not_a_num);
          set = gen_rtx_SET (VOIDmode, FP_MODE_REG (reg, SFmode), not_a_num);
          insn = emit_insn_after (set, insn);
          insn = emit_insn_after (set, insn);
          control_flow_insn_deleted |= subst_stack_regs (insn, &regstack);
          control_flow_insn_deleted |= subst_stack_regs (insn, &regstack);
        }
        }
    }
    }
 
 
  /* Amongst the insns possibly deleted during the substitution process above,
  /* Amongst the insns possibly deleted during the substitution process above,
     might have been the only trapping insn in the block.  We purge the now
     might have been the only trapping insn in the block.  We purge the now
     possibly dead EH edges here to avoid an ICE from fixup_abnormal_edges,
     possibly dead EH edges here to avoid an ICE from fixup_abnormal_edges,
     called at the end of convert_regs.  The order in which we process the
     called at the end of convert_regs.  The order in which we process the
     blocks ensures that we never delete an already processed edge.
     blocks ensures that we never delete an already processed edge.
 
 
     Note that, at this point, the CFG may have been damaged by the emission
     Note that, at this point, the CFG may have been damaged by the emission
     of instructions after an abnormal call, which moves the basic block end
     of instructions after an abnormal call, which moves the basic block end
     (and is the reason why we call fixup_abnormal_edges later).  So we must
     (and is the reason why we call fixup_abnormal_edges later).  So we must
     be sure that the trapping insn has been deleted before trying to purge
     be sure that the trapping insn has been deleted before trying to purge
     dead edges, otherwise we risk purging valid edges.
     dead edges, otherwise we risk purging valid edges.
 
 
     ??? We are normally supposed not to delete trapping insns, so we pretend
     ??? We are normally supposed not to delete trapping insns, so we pretend
     that the insns deleted above don't actually trap.  It would have been
     that the insns deleted above don't actually trap.  It would have been
     better to detect this earlier and avoid creating the EH edge in the first
     better to detect this earlier and avoid creating the EH edge in the first
     place, still, but we don't have enough information at that time.  */
     place, still, but we don't have enough information at that time.  */
 
 
  if (control_flow_insn_deleted)
  if (control_flow_insn_deleted)
    purge_dead_edges (block);
    purge_dead_edges (block);
 
 
  /* Something failed if the stack lives don't match.  If we had malformed
  /* Something failed if the stack lives don't match.  If we had malformed
     asms, we zapped the instruction itself, but that didn't produce the
     asms, we zapped the instruction itself, but that didn't produce the
     same pattern of register kills as before.  */
     same pattern of register kills as before.  */
  GO_IF_HARD_REG_EQUAL (regstack.reg_set, bi->out_reg_set, win);
  GO_IF_HARD_REG_EQUAL (regstack.reg_set, bi->out_reg_set, win);
  gcc_assert (any_malformed_asm);
  gcc_assert (any_malformed_asm);
 win:
 win:
  bi->stack_out = regstack;
  bi->stack_out = regstack;
  bi->done = true;
  bi->done = true;
}
}
 
 
/* Convert registers in all blocks reachable from BLOCK.  */
/* Convert registers in all blocks reachable from BLOCK.  */
 
 
static void
static void
convert_regs_2 (basic_block block)
convert_regs_2 (basic_block block)
{
{
  basic_block *stack, *sp;
  basic_block *stack, *sp;
 
 
  /* We process the blocks in a top-down manner, in a way such that one block
  /* We process the blocks in a top-down manner, in a way such that one block
     is only processed after all its predecessors.  The number of predecessors
     is only processed after all its predecessors.  The number of predecessors
     of every block has already been computed.  */
     of every block has already been computed.  */
 
 
  stack = XNEWVEC (basic_block, n_basic_blocks);
  stack = XNEWVEC (basic_block, n_basic_blocks);
  sp = stack;
  sp = stack;
 
 
  *sp++ = block;
  *sp++ = block;
 
 
  do
  do
    {
    {
      edge e;
      edge e;
      edge_iterator ei;
      edge_iterator ei;
 
 
      block = *--sp;
      block = *--sp;
 
 
      /* Processing BLOCK is achieved by convert_regs_1, which may purge
      /* Processing BLOCK is achieved by convert_regs_1, which may purge
         some dead EH outgoing edge after the deletion of the trapping
         some dead EH outgoing edge after the deletion of the trapping
         insn inside the block.  Since the number of predecessors of
         insn inside the block.  Since the number of predecessors of
         BLOCK's successors was computed based on the initial edge set,
         BLOCK's successors was computed based on the initial edge set,
         we check the necessity to process some of these successors
         we check the necessity to process some of these successors
         before such an edge deletion may happen.  However, there is
         before such an edge deletion may happen.  However, there is
         a pitfall: if BLOCK is the only predecessor of a successor and
         a pitfall: if BLOCK is the only predecessor of a successor and
         the edge between them happens to be deleted, the successor
         the edge between them happens to be deleted, the successor
         becomes unreachable and should not be processed.  The problem
         becomes unreachable and should not be processed.  The problem
         is that there is no way to preventively detect this case so we
         is that there is no way to preventively detect this case so we
         stack the successor in all cases and hand over the task of
         stack the successor in all cases and hand over the task of
         fixing up the discrepancy to convert_regs_1.  */
         fixing up the discrepancy to convert_regs_1.  */
 
 
      FOR_EACH_EDGE (e, ei, block->succs)
      FOR_EACH_EDGE (e, ei, block->succs)
        if (! (e->flags & EDGE_DFS_BACK))
        if (! (e->flags & EDGE_DFS_BACK))
          {
          {
            BLOCK_INFO (e->dest)->predecessors--;
            BLOCK_INFO (e->dest)->predecessors--;
            if (!BLOCK_INFO (e->dest)->predecessors)
            if (!BLOCK_INFO (e->dest)->predecessors)
              *sp++ = e->dest;
              *sp++ = e->dest;
          }
          }
 
 
      convert_regs_1 (block);
      convert_regs_1 (block);
    }
    }
  while (sp != stack);
  while (sp != stack);
 
 
  free (stack);
  free (stack);
}
}
 
 
/* Traverse all basic blocks in a function, converting the register
/* Traverse all basic blocks in a function, converting the register
   references in each insn from the "flat" register file that gcc uses,
   references in each insn from the "flat" register file that gcc uses,
   to the stack-like registers the 387 uses.  */
   to the stack-like registers the 387 uses.  */
 
 
static void
static void
convert_regs (void)
convert_regs (void)
{
{
  int inserted;
  int inserted;
  basic_block b;
  basic_block b;
  edge e;
  edge e;
  edge_iterator ei;
  edge_iterator ei;
 
 
  /* Initialize uninitialized registers on function entry.  */
  /* Initialize uninitialized registers on function entry.  */
  inserted = convert_regs_entry ();
  inserted = convert_regs_entry ();
 
 
  /* Construct the desired stack for function exit.  */
  /* Construct the desired stack for function exit.  */
  convert_regs_exit ();
  convert_regs_exit ();
  BLOCK_INFO (EXIT_BLOCK_PTR)->done = 1;
  BLOCK_INFO (EXIT_BLOCK_PTR)->done = 1;
 
 
  /* ??? Future: process inner loops first, and give them arbitrary
  /* ??? Future: process inner loops first, and give them arbitrary
     initial stacks which emit_swap_insn can modify.  This ought to
     initial stacks which emit_swap_insn can modify.  This ought to
     prevent double fxch that often appears at the head of a loop.  */
     prevent double fxch that often appears at the head of a loop.  */
 
 
  /* Process all blocks reachable from all entry points.  */
  /* Process all blocks reachable from all entry points.  */
  FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
  FOR_EACH_EDGE (e, ei, ENTRY_BLOCK_PTR->succs)
    convert_regs_2 (e->dest);
    convert_regs_2 (e->dest);
 
 
  /* ??? Process all unreachable blocks.  Though there's no excuse
  /* ??? Process all unreachable blocks.  Though there's no excuse
     for keeping these even when not optimizing.  */
     for keeping these even when not optimizing.  */
  FOR_EACH_BB (b)
  FOR_EACH_BB (b)
    {
    {
      block_info bi = BLOCK_INFO (b);
      block_info bi = BLOCK_INFO (b);
 
 
      if (! bi->done)
      if (! bi->done)
        convert_regs_2 (b);
        convert_regs_2 (b);
    }
    }
 
 
  inserted |= compensate_edges ();
  inserted |= compensate_edges ();
 
 
  clear_aux_for_blocks ();
  clear_aux_for_blocks ();
 
 
  fixup_abnormal_edges ();
  fixup_abnormal_edges ();
  if (inserted)
  if (inserted)
    commit_edge_insertions ();
    commit_edge_insertions ();
 
 
  if (dump_file)
  if (dump_file)
    fputc ('\n', dump_file);
    fputc ('\n', dump_file);
}
}


/* Convert register usage from "flat" register file usage to a "stack
/* Convert register usage from "flat" register file usage to a "stack
   register file.  FILE is the dump file, if used.
   register file.  FILE is the dump file, if used.
 
 
   Construct a CFG and run life analysis.  Then convert each insn one
   Construct a CFG and run life analysis.  Then convert each insn one
   by one.  Run a last cleanup_cfg pass, if optimizing, to eliminate
   by one.  Run a last cleanup_cfg pass, if optimizing, to eliminate
   code duplication created when the converter inserts pop insns on
   code duplication created when the converter inserts pop insns on
   the edges.  */
   the edges.  */
 
 
static bool
static bool
reg_to_stack (void)
reg_to_stack (void)
{
{
  basic_block bb;
  basic_block bb;
  int i;
  int i;
  int max_uid;
  int max_uid;
 
 
  /* Clean up previous run.  */
  /* Clean up previous run.  */
  if (stack_regs_mentioned_data != NULL)
  if (stack_regs_mentioned_data != NULL)
    VEC_free (char, heap, stack_regs_mentioned_data);
    VEC_free (char, heap, stack_regs_mentioned_data);
 
 
  /* See if there is something to do.  Flow analysis is quite
  /* See if there is something to do.  Flow analysis is quite
     expensive so we might save some compilation time.  */
     expensive so we might save some compilation time.  */
  for (i = FIRST_STACK_REG; i <= LAST_STACK_REG; i++)
  for (i = FIRST_STACK_REG; i <= LAST_STACK_REG; i++)
    if (regs_ever_live[i])
    if (regs_ever_live[i])
      break;
      break;
  if (i > LAST_STACK_REG)
  if (i > LAST_STACK_REG)
    return false;
    return false;
 
 
  /* Ok, floating point instructions exist.  If not optimizing,
  /* Ok, floating point instructions exist.  If not optimizing,
     build the CFG and run life analysis.
     build the CFG and run life analysis.
     Also need to rebuild life when superblock scheduling is done
     Also need to rebuild life when superblock scheduling is done
     as it don't update liveness yet.  */
     as it don't update liveness yet.  */
  if (!optimize
  if (!optimize
      || ((flag_sched2_use_superblocks || flag_sched2_use_traces)
      || ((flag_sched2_use_superblocks || flag_sched2_use_traces)
          && flag_schedule_insns_after_reload))
          && flag_schedule_insns_after_reload))
    {
    {
      count_or_remove_death_notes (NULL, 1);
      count_or_remove_death_notes (NULL, 1);
      life_analysis (PROP_DEATH_NOTES);
      life_analysis (PROP_DEATH_NOTES);
    }
    }
  mark_dfs_back_edges ();
  mark_dfs_back_edges ();
 
 
  /* Set up block info for each basic block.  */
  /* Set up block info for each basic block.  */
  alloc_aux_for_blocks (sizeof (struct block_info_def));
  alloc_aux_for_blocks (sizeof (struct block_info_def));
  FOR_EACH_BB (bb)
  FOR_EACH_BB (bb)
    {
    {
      block_info bi = BLOCK_INFO (bb);
      block_info bi = BLOCK_INFO (bb);
      edge_iterator ei;
      edge_iterator ei;
      edge e;
      edge e;
      int reg;
      int reg;
 
 
      FOR_EACH_EDGE (e, ei, bb->preds)
      FOR_EACH_EDGE (e, ei, bb->preds)
        if (!(e->flags & EDGE_DFS_BACK)
        if (!(e->flags & EDGE_DFS_BACK)
            && e->src != ENTRY_BLOCK_PTR)
            && e->src != ENTRY_BLOCK_PTR)
          bi->predecessors++;
          bi->predecessors++;
 
 
      /* Set current register status at last instruction `uninitialized'.  */
      /* Set current register status at last instruction `uninitialized'.  */
      bi->stack_in.top = -2;
      bi->stack_in.top = -2;
 
 
      /* Copy live_at_end and live_at_start into temporaries.  */
      /* Copy live_at_end and live_at_start into temporaries.  */
      for (reg = FIRST_STACK_REG; reg <= LAST_STACK_REG; reg++)
      for (reg = FIRST_STACK_REG; reg <= LAST_STACK_REG; reg++)
        {
        {
          if (REGNO_REG_SET_P (bb->il.rtl->global_live_at_end, reg))
          if (REGNO_REG_SET_P (bb->il.rtl->global_live_at_end, reg))
            SET_HARD_REG_BIT (bi->out_reg_set, reg);
            SET_HARD_REG_BIT (bi->out_reg_set, reg);
          if (REGNO_REG_SET_P (bb->il.rtl->global_live_at_start, reg))
          if (REGNO_REG_SET_P (bb->il.rtl->global_live_at_start, reg))
            SET_HARD_REG_BIT (bi->stack_in.reg_set, reg);
            SET_HARD_REG_BIT (bi->stack_in.reg_set, reg);
        }
        }
    }
    }
 
 
  /* Create the replacement registers up front.  */
  /* Create the replacement registers up front.  */
  for (i = FIRST_STACK_REG; i <= LAST_STACK_REG; i++)
  for (i = FIRST_STACK_REG; i <= LAST_STACK_REG; i++)
    {
    {
      enum machine_mode mode;
      enum machine_mode mode;
      for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
      for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
           mode != VOIDmode;
           mode != VOIDmode;
           mode = GET_MODE_WIDER_MODE (mode))
           mode = GET_MODE_WIDER_MODE (mode))
        FP_MODE_REG (i, mode) = gen_rtx_REG (mode, i);
        FP_MODE_REG (i, mode) = gen_rtx_REG (mode, i);
      for (mode = GET_CLASS_NARROWEST_MODE (MODE_COMPLEX_FLOAT);
      for (mode = GET_CLASS_NARROWEST_MODE (MODE_COMPLEX_FLOAT);
           mode != VOIDmode;
           mode != VOIDmode;
           mode = GET_MODE_WIDER_MODE (mode))
           mode = GET_MODE_WIDER_MODE (mode))
        FP_MODE_REG (i, mode) = gen_rtx_REG (mode, i);
        FP_MODE_REG (i, mode) = gen_rtx_REG (mode, i);
    }
    }
 
 
  ix86_flags_rtx = gen_rtx_REG (CCmode, FLAGS_REG);
  ix86_flags_rtx = gen_rtx_REG (CCmode, FLAGS_REG);
 
 
  /* A QNaN for initializing uninitialized variables.
  /* A QNaN for initializing uninitialized variables.
 
 
     ??? We can't load from constant memory in PIC mode, because
     ??? We can't load from constant memory in PIC mode, because
     we're inserting these instructions before the prologue and
     we're inserting these instructions before the prologue and
     the PIC register hasn't been set up.  In that case, fall back
     the PIC register hasn't been set up.  In that case, fall back
     on zero, which we can get from `ldz'.  */
     on zero, which we can get from `ldz'.  */
 
 
  if (flag_pic)
  if (flag_pic)
    not_a_num = CONST0_RTX (SFmode);
    not_a_num = CONST0_RTX (SFmode);
  else
  else
    {
    {
      not_a_num = gen_lowpart (SFmode, GEN_INT (0x7fc00000));
      not_a_num = gen_lowpart (SFmode, GEN_INT (0x7fc00000));
      not_a_num = force_const_mem (SFmode, not_a_num);
      not_a_num = force_const_mem (SFmode, not_a_num);
    }
    }
 
 
  /* Allocate a cache for stack_regs_mentioned.  */
  /* Allocate a cache for stack_regs_mentioned.  */
  max_uid = get_max_uid ();
  max_uid = get_max_uid ();
  stack_regs_mentioned_data = VEC_alloc (char, heap, max_uid + 1);
  stack_regs_mentioned_data = VEC_alloc (char, heap, max_uid + 1);
  memset (VEC_address (char, stack_regs_mentioned_data),
  memset (VEC_address (char, stack_regs_mentioned_data),
          0, sizeof (char) * max_uid + 1);
          0, sizeof (char) * max_uid + 1);
 
 
  convert_regs ();
  convert_regs ();
 
 
  free_aux_for_blocks ();
  free_aux_for_blocks ();
  return true;
  return true;
}
}
#endif /* STACK_REGS */
#endif /* STACK_REGS */


static bool
static bool
gate_handle_stack_regs (void)
gate_handle_stack_regs (void)
{
{
#ifdef STACK_REGS
#ifdef STACK_REGS
  return 1;
  return 1;
#else
#else
  return 0;
  return 0;
#endif
#endif
}
}
 
 
/* Convert register usage from flat register file usage to a stack
/* Convert register usage from flat register file usage to a stack
   register file.  */
   register file.  */
static unsigned int
static unsigned int
rest_of_handle_stack_regs (void)
rest_of_handle_stack_regs (void)
{
{
#ifdef STACK_REGS
#ifdef STACK_REGS
  if (reg_to_stack () && optimize)
  if (reg_to_stack () && optimize)
    {
    {
      regstack_completed = 1;
      regstack_completed = 1;
      if (cleanup_cfg (CLEANUP_EXPENSIVE | CLEANUP_POST_REGSTACK
      if (cleanup_cfg (CLEANUP_EXPENSIVE | CLEANUP_POST_REGSTACK
                       | (flag_crossjumping ? CLEANUP_CROSSJUMP : 0))
                       | (flag_crossjumping ? CLEANUP_CROSSJUMP : 0))
          && (flag_reorder_blocks || flag_reorder_blocks_and_partition))
          && (flag_reorder_blocks || flag_reorder_blocks_and_partition))
        {
        {
          reorder_basic_blocks (0);
          reorder_basic_blocks (0);
          cleanup_cfg (CLEANUP_EXPENSIVE | CLEANUP_POST_REGSTACK);
          cleanup_cfg (CLEANUP_EXPENSIVE | CLEANUP_POST_REGSTACK);
        }
        }
    }
    }
  else
  else
    regstack_completed = 1;
    regstack_completed = 1;
#endif
#endif
  return 0;
  return 0;
}
}
 
 
struct tree_opt_pass pass_stack_regs =
struct tree_opt_pass pass_stack_regs =
{
{
  "stack",                              /* name */
  "stack",                              /* name */
  gate_handle_stack_regs,               /* gate */
  gate_handle_stack_regs,               /* gate */
  rest_of_handle_stack_regs,            /* execute */
  rest_of_handle_stack_regs,            /* execute */
  NULL,                                 /* sub */
  NULL,                                 /* sub */
  NULL,                                 /* next */
  NULL,                                 /* next */
  0,                                    /* static_pass_number */
  0,                                    /* static_pass_number */
  TV_REG_STACK,                         /* tv_id */
  TV_REG_STACK,                         /* tv_id */
  0,                                    /* properties_required */
  0,                                    /* properties_required */
  0,                                    /* properties_provided */
  0,                                    /* properties_provided */
  0,                                    /* properties_destroyed */
  0,                                    /* properties_destroyed */
  0,                                    /* todo_flags_start */
  0,                                    /* todo_flags_start */
  TODO_dump_func |
  TODO_dump_func |
  TODO_ggc_collect,                     /* todo_flags_finish */
  TODO_ggc_collect,                     /* todo_flags_finish */
  'k'                                   /* letter */
  'k'                                   /* letter */
};
};
 
 

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