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/* RTL-level loop invariant motion.
/* RTL-level loop invariant motion.
   Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
   Copyright (C) 2004, 2005, 2006, 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 the
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 3, or (at your option) any
Free Software Foundation; either version 3, or (at your option) any
later version.
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 or
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.
for more details.
 
 
You should have received a copy of the GNU General Public License
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */
<http://www.gnu.org/licenses/>.  */
 
 
/* This implements the loop invariant motion pass.  It is very simple
/* This implements the loop invariant motion pass.  It is very simple
   (no calls, libcalls, etc.).  This should be sufficient to cleanup things
   (no calls, libcalls, etc.).  This should be sufficient to cleanup things
   like address arithmetics -- other more complicated invariants should be
   like address arithmetics -- other more complicated invariants should be
   eliminated on tree level either in tree-ssa-loop-im.c or in tree-ssa-pre.c.
   eliminated on tree level either in tree-ssa-loop-im.c or in tree-ssa-pre.c.
 
 
   We proceed loop by loop -- it is simpler than trying to handle things
   We proceed loop by loop -- it is simpler than trying to handle things
   globally and should not lose much.  First we inspect all sets inside loop
   globally and should not lose much.  First we inspect all sets inside loop
   and create a dependency graph on insns (saying "to move this insn, you must
   and create a dependency graph on insns (saying "to move this insn, you must
   also move the following insns").
   also move the following insns").
 
 
   We then need to determine what to move.  We estimate the number of registers
   We then need to determine what to move.  We estimate the number of registers
   used and move as many invariants as possible while we still have enough free
   used and move as many invariants as possible while we still have enough free
   registers.  We prefer the expensive invariants.
   registers.  We prefer the expensive invariants.
 
 
   Then we move the selected invariants out of the loop, creating a new
   Then we move the selected invariants out of the loop, creating a new
   temporaries for them if necessary.  */
   temporaries for them if necessary.  */
 
 
#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 "rtl.h"
#include "rtl.h"
#include "tm_p.h"
#include "tm_p.h"
#include "hard-reg-set.h"
#include "hard-reg-set.h"
#include "obstack.h"
#include "obstack.h"
#include "basic-block.h"
#include "basic-block.h"
#include "cfgloop.h"
#include "cfgloop.h"
#include "expr.h"
#include "expr.h"
#include "recog.h"
#include "recog.h"
#include "output.h"
#include "output.h"
#include "function.h"
#include "function.h"
#include "flags.h"
#include "flags.h"
#include "df.h"
#include "df.h"
#include "hashtab.h"
#include "hashtab.h"
#include "except.h"
#include "except.h"
 
 
/* The data stored for the loop.  */
/* The data stored for the loop.  */
 
 
struct loop_data
struct loop_data
{
{
  struct loop *outermost_exit;  /* The outermost exit of the loop.  */
  struct loop *outermost_exit;  /* The outermost exit of the loop.  */
  bool has_call;                /* True if the loop contains a call.  */
  bool has_call;                /* True if the loop contains a call.  */
};
};
 
 
#define LOOP_DATA(LOOP) ((struct loop_data *) (LOOP)->aux)
#define LOOP_DATA(LOOP) ((struct loop_data *) (LOOP)->aux)
 
 
/* The description of an use.  */
/* The description of an use.  */
 
 
struct use
struct use
{
{
  rtx *pos;                     /* Position of the use.  */
  rtx *pos;                     /* Position of the use.  */
  rtx insn;                     /* The insn in that the use occurs.  */
  rtx insn;                     /* The insn in that the use occurs.  */
 
 
  struct use *next;             /* Next use in the list.  */
  struct use *next;             /* Next use in the list.  */
};
};
 
 
/* The description of a def.  */
/* The description of a def.  */
 
 
struct def
struct def
{
{
  struct use *uses;             /* The list of uses that are uniquely reached
  struct use *uses;             /* The list of uses that are uniquely reached
                                   by it.  */
                                   by it.  */
  unsigned n_uses;              /* Number of such uses.  */
  unsigned n_uses;              /* Number of such uses.  */
  unsigned invno;               /* The corresponding invariant.  */
  unsigned invno;               /* The corresponding invariant.  */
};
};
 
 
/* The data stored for each invariant.  */
/* The data stored for each invariant.  */
 
 
struct invariant
struct invariant
{
{
  /* The number of the invariant.  */
  /* The number of the invariant.  */
  unsigned invno;
  unsigned invno;
 
 
  /* The number of the invariant with the same value.  */
  /* The number of the invariant with the same value.  */
  unsigned eqto;
  unsigned eqto;
 
 
  /* If we moved the invariant out of the loop, the register that contains its
  /* If we moved the invariant out of the loop, the register that contains its
     value.  */
     value.  */
  rtx reg;
  rtx reg;
 
 
  /* The definition of the invariant.  */
  /* The definition of the invariant.  */
  struct def *def;
  struct def *def;
 
 
  /* The insn in that it is defined.  */
  /* The insn in that it is defined.  */
  rtx insn;
  rtx insn;
 
 
  /* Whether it is always executed.  */
  /* Whether it is always executed.  */
  bool always_executed;
  bool always_executed;
 
 
  /* Whether to move the invariant.  */
  /* Whether to move the invariant.  */
  bool move;
  bool move;
 
 
  /* Cost of the invariant.  */
  /* Cost of the invariant.  */
  unsigned cost;
  unsigned cost;
 
 
  /* The invariants it depends on.  */
  /* The invariants it depends on.  */
  bitmap depends_on;
  bitmap depends_on;
 
 
  /* Used for detecting already visited invariants during determining
  /* Used for detecting already visited invariants during determining
     costs of movements.  */
     costs of movements.  */
  unsigned stamp;
  unsigned stamp;
};
};
 
 
/* Entry for hash table of invariant expressions.  */
/* Entry for hash table of invariant expressions.  */
 
 
struct invariant_expr_entry
struct invariant_expr_entry
{
{
  /* The invariant.  */
  /* The invariant.  */
  struct invariant *inv;
  struct invariant *inv;
 
 
  /* Its value.  */
  /* Its value.  */
  rtx expr;
  rtx expr;
 
 
  /* Its mode.  */
  /* Its mode.  */
  enum machine_mode mode;
  enum machine_mode mode;
 
 
  /* Its hash.  */
  /* Its hash.  */
  hashval_t hash;
  hashval_t hash;
};
};
 
 
/* The actual stamp for marking already visited invariants during determining
/* The actual stamp for marking already visited invariants during determining
   costs of movements.  */
   costs of movements.  */
 
 
static unsigned actual_stamp;
static unsigned actual_stamp;
 
 
typedef struct invariant *invariant_p;
typedef struct invariant *invariant_p;
 
 
DEF_VEC_P(invariant_p);
DEF_VEC_P(invariant_p);
DEF_VEC_ALLOC_P(invariant_p, heap);
DEF_VEC_ALLOC_P(invariant_p, heap);
 
 
/* The invariants.  */
/* The invariants.  */
 
 
static VEC(invariant_p,heap) *invariants;
static VEC(invariant_p,heap) *invariants;
 
 
/* The dataflow object.  */
/* The dataflow object.  */
 
 
static struct df *df = NULL;
static struct df *df = NULL;
 
 
/* Test for possibility of invariantness of X.  */
/* Test for possibility of invariantness of X.  */
 
 
static bool
static bool
check_maybe_invariant (rtx x)
check_maybe_invariant (rtx x)
{
{
  enum rtx_code code = GET_CODE (x);
  enum rtx_code code = GET_CODE (x);
  int i, j;
  int i, j;
  const char *fmt;
  const char *fmt;
 
 
  switch (code)
  switch (code)
    {
    {
    case CONST_INT:
    case CONST_INT:
    case CONST_DOUBLE:
    case CONST_DOUBLE:
    case SYMBOL_REF:
    case SYMBOL_REF:
    case CONST:
    case CONST:
    case LABEL_REF:
    case LABEL_REF:
      return true;
      return true;
 
 
    case PC:
    case PC:
    case CC0:
    case CC0:
    case UNSPEC_VOLATILE:
    case UNSPEC_VOLATILE:
    case CALL:
    case CALL:
      return false;
      return false;
 
 
    case REG:
    case REG:
      return true;
      return true;
 
 
    case MEM:
    case MEM:
      /* Load/store motion is done elsewhere.  ??? Perhaps also add it here?
      /* Load/store motion is done elsewhere.  ??? Perhaps also add it here?
         It should not be hard, and might be faster than "elsewhere".  */
         It should not be hard, and might be faster than "elsewhere".  */
 
 
      /* Just handle the most trivial case where we load from an unchanging
      /* Just handle the most trivial case where we load from an unchanging
         location (most importantly, pic tables).  */
         location (most importantly, pic tables).  */
      if (MEM_READONLY_P (x))
      if (MEM_READONLY_P (x))
        break;
        break;
 
 
      return false;
      return false;
 
 
    case ASM_OPERANDS:
    case ASM_OPERANDS:
      /* Don't mess with insns declared volatile.  */
      /* Don't mess with insns declared volatile.  */
      if (MEM_VOLATILE_P (x))
      if (MEM_VOLATILE_P (x))
        return false;
        return false;
      break;
      break;
 
 
    default:
    default:
      break;
      break;
    }
    }
 
 
  fmt = GET_RTX_FORMAT (code);
  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
    {
      if (fmt[i] == 'e')
      if (fmt[i] == 'e')
        {
        {
          if (!check_maybe_invariant (XEXP (x, i)))
          if (!check_maybe_invariant (XEXP (x, i)))
            return false;
            return false;
        }
        }
      else if (fmt[i] == 'E')
      else if (fmt[i] == 'E')
        {
        {
          for (j = 0; j < XVECLEN (x, i); j++)
          for (j = 0; j < XVECLEN (x, i); j++)
            if (!check_maybe_invariant (XVECEXP (x, i, j)))
            if (!check_maybe_invariant (XVECEXP (x, i, j)))
              return false;
              return false;
        }
        }
    }
    }
 
 
  return true;
  return true;
}
}
 
 
/* Returns the invariant definition for USE, or NULL if USE is not
/* Returns the invariant definition for USE, or NULL if USE is not
   invariant.  */
   invariant.  */
 
 
static struct invariant *
static struct invariant *
invariant_for_use (struct df_ref *use)
invariant_for_use (struct df_ref *use)
{
{
  struct df_link *defs;
  struct df_link *defs;
  struct df_ref *def;
  struct df_ref *def;
  basic_block bb = BLOCK_FOR_INSN (use->insn), def_bb;
  basic_block bb = BLOCK_FOR_INSN (use->insn), def_bb;
 
 
  if (use->flags & DF_REF_READ_WRITE)
  if (use->flags & DF_REF_READ_WRITE)
    return NULL;
    return NULL;
 
 
  defs = DF_REF_CHAIN (use);
  defs = DF_REF_CHAIN (use);
  if (!defs || defs->next)
  if (!defs || defs->next)
    return NULL;
    return NULL;
  def = defs->ref;
  def = defs->ref;
  if (!DF_REF_DATA (def))
  if (!DF_REF_DATA (def))
    return NULL;
    return NULL;
 
 
  def_bb = DF_REF_BB (def);
  def_bb = DF_REF_BB (def);
  if (!dominated_by_p (CDI_DOMINATORS, bb, def_bb))
  if (!dominated_by_p (CDI_DOMINATORS, bb, def_bb))
    return NULL;
    return NULL;
  return DF_REF_DATA (def);
  return DF_REF_DATA (def);
}
}
 
 
/* Computes hash value for invariant expression X in INSN.  */
/* Computes hash value for invariant expression X in INSN.  */
 
 
static hashval_t
static hashval_t
hash_invariant_expr_1 (rtx insn, rtx x)
hash_invariant_expr_1 (rtx insn, rtx x)
{
{
  enum rtx_code code = GET_CODE (x);
  enum rtx_code code = GET_CODE (x);
  int i, j;
  int i, j;
  const char *fmt;
  const char *fmt;
  hashval_t val = code;
  hashval_t val = code;
  int do_not_record_p;
  int do_not_record_p;
  struct df_ref *use;
  struct df_ref *use;
  struct invariant *inv;
  struct invariant *inv;
 
 
  switch (code)
  switch (code)
    {
    {
    case CONST_INT:
    case CONST_INT:
    case CONST_DOUBLE:
    case CONST_DOUBLE:
    case SYMBOL_REF:
    case SYMBOL_REF:
    case CONST:
    case CONST:
    case LABEL_REF:
    case LABEL_REF:
      return hash_rtx (x, GET_MODE (x), &do_not_record_p, NULL, false);
      return hash_rtx (x, GET_MODE (x), &do_not_record_p, NULL, false);
 
 
    case REG:
    case REG:
      use = df_find_use (df, insn, x);
      use = df_find_use (df, insn, x);
      if (!use)
      if (!use)
        return hash_rtx (x, GET_MODE (x), &do_not_record_p, NULL, false);
        return hash_rtx (x, GET_MODE (x), &do_not_record_p, NULL, false);
      inv = invariant_for_use (use);
      inv = invariant_for_use (use);
      if (!inv)
      if (!inv)
        return hash_rtx (x, GET_MODE (x), &do_not_record_p, NULL, false);
        return hash_rtx (x, GET_MODE (x), &do_not_record_p, NULL, false);
 
 
      gcc_assert (inv->eqto != ~0u);
      gcc_assert (inv->eqto != ~0u);
      return inv->eqto;
      return inv->eqto;
 
 
    default:
    default:
      break;
      break;
    }
    }
 
 
  fmt = GET_RTX_FORMAT (code);
  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
    {
      if (fmt[i] == 'e')
      if (fmt[i] == 'e')
        val ^= hash_invariant_expr_1 (insn, XEXP (x, i));
        val ^= hash_invariant_expr_1 (insn, XEXP (x, i));
      else if (fmt[i] == 'E')
      else if (fmt[i] == 'E')
        {
        {
          for (j = 0; j < XVECLEN (x, i); j++)
          for (j = 0; j < XVECLEN (x, i); j++)
            val ^= hash_invariant_expr_1 (insn, XVECEXP (x, i, j));
            val ^= hash_invariant_expr_1 (insn, XVECEXP (x, i, j));
        }
        }
      else if (fmt[i] == 'i' || fmt[i] == 'n')
      else if (fmt[i] == 'i' || fmt[i] == 'n')
        val ^= XINT (x, i);
        val ^= XINT (x, i);
    }
    }
 
 
  return val;
  return val;
}
}
 
 
/* Returns true if the invariant expressions E1 and E2 used in insns INSN1
/* Returns true if the invariant expressions E1 and E2 used in insns INSN1
   and INSN2 have always the same value.  */
   and INSN2 have always the same value.  */
 
 
static bool
static bool
invariant_expr_equal_p (rtx insn1, rtx e1, rtx insn2, rtx e2)
invariant_expr_equal_p (rtx insn1, rtx e1, rtx insn2, rtx e2)
{
{
  enum rtx_code code = GET_CODE (e1);
  enum rtx_code code = GET_CODE (e1);
  int i, j;
  int i, j;
  const char *fmt;
  const char *fmt;
  struct df_ref *use1, *use2;
  struct df_ref *use1, *use2;
  struct invariant *inv1 = NULL, *inv2 = NULL;
  struct invariant *inv1 = NULL, *inv2 = NULL;
  rtx sub1, sub2;
  rtx sub1, sub2;
 
 
  /* If mode of only one of the operands is VOIDmode, it is not equivalent to
  /* If mode of only one of the operands is VOIDmode, it is not equivalent to
     the other one.  If both are VOIDmode, we rely on the caller of this
     the other one.  If both are VOIDmode, we rely on the caller of this
     function to verify that their modes are the same.  */
     function to verify that their modes are the same.  */
  if (code != GET_CODE (e2) || GET_MODE (e1) != GET_MODE (e2))
  if (code != GET_CODE (e2) || GET_MODE (e1) != GET_MODE (e2))
    return false;
    return false;
 
 
  switch (code)
  switch (code)
    {
    {
    case CONST_INT:
    case CONST_INT:
    case CONST_DOUBLE:
    case CONST_DOUBLE:
    case SYMBOL_REF:
    case SYMBOL_REF:
    case CONST:
    case CONST:
    case LABEL_REF:
    case LABEL_REF:
      return rtx_equal_p (e1, e2);
      return rtx_equal_p (e1, e2);
 
 
    case REG:
    case REG:
      use1 = df_find_use (df, insn1, e1);
      use1 = df_find_use (df, insn1, e1);
      use2 = df_find_use (df, insn2, e2);
      use2 = df_find_use (df, insn2, e2);
      if (use1)
      if (use1)
        inv1 = invariant_for_use (use1);
        inv1 = invariant_for_use (use1);
      if (use2)
      if (use2)
        inv2 = invariant_for_use (use2);
        inv2 = invariant_for_use (use2);
 
 
      if (!inv1 && !inv2)
      if (!inv1 && !inv2)
        return rtx_equal_p (e1, e2);
        return rtx_equal_p (e1, e2);
 
 
      if (!inv1 || !inv2)
      if (!inv1 || !inv2)
        return false;
        return false;
 
 
      gcc_assert (inv1->eqto != ~0u);
      gcc_assert (inv1->eqto != ~0u);
      gcc_assert (inv2->eqto != ~0u);
      gcc_assert (inv2->eqto != ~0u);
      return inv1->eqto == inv2->eqto;
      return inv1->eqto == inv2->eqto;
 
 
    default:
    default:
      break;
      break;
    }
    }
 
 
  fmt = GET_RTX_FORMAT (code);
  fmt = GET_RTX_FORMAT (code);
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
    {
      if (fmt[i] == 'e')
      if (fmt[i] == 'e')
        {
        {
          sub1 = XEXP (e1, i);
          sub1 = XEXP (e1, i);
          sub2 = XEXP (e2, i);
          sub2 = XEXP (e2, i);
 
 
          if (!invariant_expr_equal_p (insn1, sub1, insn2, sub2))
          if (!invariant_expr_equal_p (insn1, sub1, insn2, sub2))
            return false;
            return false;
        }
        }
 
 
      else if (fmt[i] == 'E')
      else if (fmt[i] == 'E')
        {
        {
          if (XVECLEN (e1, i) != XVECLEN (e2, i))
          if (XVECLEN (e1, i) != XVECLEN (e2, i))
            return false;
            return false;
 
 
          for (j = 0; j < XVECLEN (e1, i); j++)
          for (j = 0; j < XVECLEN (e1, i); j++)
            {
            {
              sub1 = XVECEXP (e1, i, j);
              sub1 = XVECEXP (e1, i, j);
              sub2 = XVECEXP (e2, i, j);
              sub2 = XVECEXP (e2, i, j);
 
 
              if (!invariant_expr_equal_p (insn1, sub1, insn2, sub2))
              if (!invariant_expr_equal_p (insn1, sub1, insn2, sub2))
                return false;
                return false;
            }
            }
        }
        }
      else if (fmt[i] == 'i' || fmt[i] == 'n')
      else if (fmt[i] == 'i' || fmt[i] == 'n')
        {
        {
          if (XINT (e1, i) != XINT (e2, i))
          if (XINT (e1, i) != XINT (e2, i))
            return false;
            return false;
        }
        }
      /* Unhandled type of subexpression, we fail conservatively.  */
      /* Unhandled type of subexpression, we fail conservatively.  */
      else
      else
        return false;
        return false;
    }
    }
 
 
  return true;
  return true;
}
}
 
 
/* Returns hash value for invariant expression entry E.  */
/* Returns hash value for invariant expression entry E.  */
 
 
static hashval_t
static hashval_t
hash_invariant_expr (const void *e)
hash_invariant_expr (const void *e)
{
{
  const struct invariant_expr_entry *entry = e;
  const struct invariant_expr_entry *entry = e;
 
 
  return entry->hash;
  return entry->hash;
}
}
 
 
/* Compares invariant expression entries E1 and E2.  */
/* Compares invariant expression entries E1 and E2.  */
 
 
static int
static int
eq_invariant_expr (const void *e1, const void *e2)
eq_invariant_expr (const void *e1, const void *e2)
{
{
  const struct invariant_expr_entry *entry1 = e1;
  const struct invariant_expr_entry *entry1 = e1;
  const struct invariant_expr_entry *entry2 = e2;
  const struct invariant_expr_entry *entry2 = e2;
 
 
  if (entry1->mode != entry2->mode)
  if (entry1->mode != entry2->mode)
    return 0;
    return 0;
 
 
  return invariant_expr_equal_p (entry1->inv->insn, entry1->expr,
  return invariant_expr_equal_p (entry1->inv->insn, entry1->expr,
                                 entry2->inv->insn, entry2->expr);
                                 entry2->inv->insn, entry2->expr);
}
}
 
 
/* Checks whether invariant with value EXPR in machine mode MODE is
/* Checks whether invariant with value EXPR in machine mode MODE is
   recorded in EQ.  If this is the case, return the invariant.  Otherwise
   recorded in EQ.  If this is the case, return the invariant.  Otherwise
   insert INV to the table for this expression and return INV.  */
   insert INV to the table for this expression and return INV.  */
 
 
static struct invariant *
static struct invariant *
find_or_insert_inv (htab_t eq, rtx expr, enum machine_mode mode,
find_or_insert_inv (htab_t eq, rtx expr, enum machine_mode mode,
                    struct invariant *inv)
                    struct invariant *inv)
{
{
  hashval_t hash = hash_invariant_expr_1 (inv->insn, expr);
  hashval_t hash = hash_invariant_expr_1 (inv->insn, expr);
  struct invariant_expr_entry *entry;
  struct invariant_expr_entry *entry;
  struct invariant_expr_entry pentry;
  struct invariant_expr_entry pentry;
  PTR *slot;
  PTR *slot;
 
 
  pentry.expr = expr;
  pentry.expr = expr;
  pentry.inv = inv;
  pentry.inv = inv;
  pentry.mode = mode;
  pentry.mode = mode;
  slot = htab_find_slot_with_hash (eq, &pentry, hash, INSERT);
  slot = htab_find_slot_with_hash (eq, &pentry, hash, INSERT);
  entry = *slot;
  entry = *slot;
 
 
  if (entry)
  if (entry)
    return entry->inv;
    return entry->inv;
 
 
  entry = XNEW (struct invariant_expr_entry);
  entry = XNEW (struct invariant_expr_entry);
  entry->inv = inv;
  entry->inv = inv;
  entry->expr = expr;
  entry->expr = expr;
  entry->mode = mode;
  entry->mode = mode;
  entry->hash = hash;
  entry->hash = hash;
  *slot = entry;
  *slot = entry;
 
 
  return inv;
  return inv;
}
}
 
 
/* Finds invariants identical to INV and records the equivalence.  EQ is the
/* Finds invariants identical to INV and records the equivalence.  EQ is the
   hash table of the invariants.  */
   hash table of the invariants.  */
 
 
static void
static void
find_identical_invariants (htab_t eq, struct invariant *inv)
find_identical_invariants (htab_t eq, struct invariant *inv)
{
{
  unsigned depno;
  unsigned depno;
  bitmap_iterator bi;
  bitmap_iterator bi;
  struct invariant *dep;
  struct invariant *dep;
  rtx expr, set;
  rtx expr, set;
  enum machine_mode mode;
  enum machine_mode mode;
 
 
  if (inv->eqto != ~0u)
  if (inv->eqto != ~0u)
    return;
    return;
 
 
  EXECUTE_IF_SET_IN_BITMAP (inv->depends_on, 0, depno, bi)
  EXECUTE_IF_SET_IN_BITMAP (inv->depends_on, 0, depno, bi)
    {
    {
      dep = VEC_index (invariant_p, invariants, depno);
      dep = VEC_index (invariant_p, invariants, depno);
      find_identical_invariants (eq, dep);
      find_identical_invariants (eq, dep);
    }
    }
 
 
  set = single_set (inv->insn);
  set = single_set (inv->insn);
  expr = SET_SRC (set);
  expr = SET_SRC (set);
  mode = GET_MODE (expr);
  mode = GET_MODE (expr);
  if (mode == VOIDmode)
  if (mode == VOIDmode)
    mode = GET_MODE (SET_DEST (set));
    mode = GET_MODE (SET_DEST (set));
  inv->eqto = find_or_insert_inv (eq, expr, mode, inv)->invno;
  inv->eqto = find_or_insert_inv (eq, expr, mode, inv)->invno;
 
 
  if (dump_file && inv->eqto != inv->invno)
  if (dump_file && inv->eqto != inv->invno)
    fprintf (dump_file,
    fprintf (dump_file,
             "Invariant %d is equivalent to invariant %d.\n",
             "Invariant %d is equivalent to invariant %d.\n",
             inv->invno, inv->eqto);
             inv->invno, inv->eqto);
}
}
 
 
/* Find invariants with the same value and record the equivalences.  */
/* Find invariants with the same value and record the equivalences.  */
 
 
static void
static void
merge_identical_invariants (void)
merge_identical_invariants (void)
{
{
  unsigned i;
  unsigned i;
  struct invariant *inv;
  struct invariant *inv;
  htab_t eq = htab_create (VEC_length (invariant_p, invariants),
  htab_t eq = htab_create (VEC_length (invariant_p, invariants),
                           hash_invariant_expr, eq_invariant_expr, free);
                           hash_invariant_expr, eq_invariant_expr, free);
 
 
  for (i = 0; VEC_iterate (invariant_p, invariants, i, inv); i++)
  for (i = 0; VEC_iterate (invariant_p, invariants, i, inv); i++)
    find_identical_invariants (eq, inv);
    find_identical_invariants (eq, inv);
 
 
  htab_delete (eq);
  htab_delete (eq);
}
}
 
 
/* Determines the basic blocks inside LOOP that are always executed and
/* Determines the basic blocks inside LOOP that are always executed and
   stores their bitmap to ALWAYS_REACHED.  MAY_EXIT is a bitmap of
   stores their bitmap to ALWAYS_REACHED.  MAY_EXIT is a bitmap of
   basic blocks that may either exit the loop, or contain the call that
   basic blocks that may either exit the loop, or contain the call that
   does not have to return.  BODY is body of the loop obtained by
   does not have to return.  BODY is body of the loop obtained by
   get_loop_body_in_dom_order.  */
   get_loop_body_in_dom_order.  */
 
 
static void
static void
compute_always_reached (struct loop *loop, basic_block *body,
compute_always_reached (struct loop *loop, basic_block *body,
                        bitmap may_exit, bitmap always_reached)
                        bitmap may_exit, bitmap always_reached)
{
{
  unsigned i;
  unsigned i;
 
 
  for (i = 0; i < loop->num_nodes; i++)
  for (i = 0; i < loop->num_nodes; i++)
    {
    {
      if (dominated_by_p (CDI_DOMINATORS, loop->latch, body[i]))
      if (dominated_by_p (CDI_DOMINATORS, loop->latch, body[i]))
        bitmap_set_bit (always_reached, i);
        bitmap_set_bit (always_reached, i);
 
 
      if (bitmap_bit_p (may_exit, i))
      if (bitmap_bit_p (may_exit, i))
        return;
        return;
    }
    }
}
}
 
 
/* Finds exits out of the LOOP with body BODY.  Marks blocks in that we may
/* Finds exits out of the LOOP with body BODY.  Marks blocks in that we may
   exit the loop by cfg edge to HAS_EXIT and MAY_EXIT.  In MAY_EXIT
   exit the loop by cfg edge to HAS_EXIT and MAY_EXIT.  In MAY_EXIT
   additionally mark blocks that may exit due to a call.  */
   additionally mark blocks that may exit due to a call.  */
 
 
static void
static void
find_exits (struct loop *loop, basic_block *body,
find_exits (struct loop *loop, basic_block *body,
            bitmap may_exit, bitmap has_exit)
            bitmap may_exit, bitmap has_exit)
{
{
  unsigned i;
  unsigned i;
  edge_iterator ei;
  edge_iterator ei;
  edge e;
  edge e;
  struct loop *outermost_exit = loop, *aexit;
  struct loop *outermost_exit = loop, *aexit;
  bool has_call = false;
  bool has_call = false;
  rtx insn;
  rtx insn;
 
 
  for (i = 0; i < loop->num_nodes; i++)
  for (i = 0; i < loop->num_nodes; i++)
    {
    {
      if (body[i]->loop_father == loop)
      if (body[i]->loop_father == loop)
        {
        {
          FOR_BB_INSNS (body[i], insn)
          FOR_BB_INSNS (body[i], insn)
            {
            {
              if (CALL_P (insn)
              if (CALL_P (insn)
                  && !CONST_OR_PURE_CALL_P (insn))
                  && !CONST_OR_PURE_CALL_P (insn))
                {
                {
                  has_call = true;
                  has_call = true;
                  bitmap_set_bit (may_exit, i);
                  bitmap_set_bit (may_exit, i);
                  break;
                  break;
                }
                }
            }
            }
 
 
          FOR_EACH_EDGE (e, ei, body[i]->succs)
          FOR_EACH_EDGE (e, ei, body[i]->succs)
            {
            {
              if (flow_bb_inside_loop_p (loop, e->dest))
              if (flow_bb_inside_loop_p (loop, e->dest))
                continue;
                continue;
 
 
              bitmap_set_bit (may_exit, i);
              bitmap_set_bit (may_exit, i);
              bitmap_set_bit (has_exit, i);
              bitmap_set_bit (has_exit, i);
              outermost_exit = find_common_loop (outermost_exit,
              outermost_exit = find_common_loop (outermost_exit,
                                                 e->dest->loop_father);
                                                 e->dest->loop_father);
            }
            }
          continue;
          continue;
        }
        }
 
 
      /* Use the data stored for the subloop to decide whether we may exit
      /* Use the data stored for the subloop to decide whether we may exit
         through it.  It is sufficient to do this for header of the loop,
         through it.  It is sufficient to do this for header of the loop,
         as other basic blocks inside it must be dominated by it.  */
         as other basic blocks inside it must be dominated by it.  */
      if (body[i]->loop_father->header != body[i])
      if (body[i]->loop_father->header != body[i])
        continue;
        continue;
 
 
      if (LOOP_DATA (body[i]->loop_father)->has_call)
      if (LOOP_DATA (body[i]->loop_father)->has_call)
        {
        {
          has_call = true;
          has_call = true;
          bitmap_set_bit (may_exit, i);
          bitmap_set_bit (may_exit, i);
        }
        }
      aexit = LOOP_DATA (body[i]->loop_father)->outermost_exit;
      aexit = LOOP_DATA (body[i]->loop_father)->outermost_exit;
      if (aexit != loop)
      if (aexit != loop)
        {
        {
          bitmap_set_bit (may_exit, i);
          bitmap_set_bit (may_exit, i);
          bitmap_set_bit (has_exit, i);
          bitmap_set_bit (has_exit, i);
 
 
          if (flow_loop_nested_p (aexit, outermost_exit))
          if (flow_loop_nested_p (aexit, outermost_exit))
            outermost_exit = aexit;
            outermost_exit = aexit;
        }
        }
    }
    }
 
 
  loop->aux = xcalloc (1, sizeof (struct loop_data));
  loop->aux = xcalloc (1, sizeof (struct loop_data));
  LOOP_DATA (loop)->outermost_exit = outermost_exit;
  LOOP_DATA (loop)->outermost_exit = outermost_exit;
  LOOP_DATA (loop)->has_call = has_call;
  LOOP_DATA (loop)->has_call = has_call;
}
}
 
 
/* Check whether we may assign a value to X from a register.  */
/* Check whether we may assign a value to X from a register.  */
 
 
static bool
static bool
may_assign_reg_p (rtx x)
may_assign_reg_p (rtx x)
{
{
  return (GET_MODE (x) != VOIDmode
  return (GET_MODE (x) != VOIDmode
          && GET_MODE (x) != BLKmode
          && GET_MODE (x) != BLKmode
          && can_copy_p (GET_MODE (x))
          && can_copy_p (GET_MODE (x))
          && (!REG_P (x)
          && (!REG_P (x)
              || !HARD_REGISTER_P (x)
              || !HARD_REGISTER_P (x)
              || REGNO_REG_CLASS (REGNO (x)) != NO_REGS));
              || REGNO_REG_CLASS (REGNO (x)) != NO_REGS));
}
}
 
 
/* Finds definitions that may correspond to invariants in LOOP with body
/* Finds definitions that may correspond to invariants in LOOP with body
   BODY.  */
   BODY.  */
 
 
static void
static void
find_defs (struct loop *loop, basic_block *body)
find_defs (struct loop *loop, basic_block *body)
{
{
  unsigned i;
  unsigned i;
  bitmap blocks = BITMAP_ALLOC (NULL);
  bitmap blocks = BITMAP_ALLOC (NULL);
 
 
  for (i = 0; i < loop->num_nodes; i++)
  for (i = 0; i < loop->num_nodes; i++)
    bitmap_set_bit (blocks, body[i]->index);
    bitmap_set_bit (blocks, body[i]->index);
 
 
  df_set_blocks (df, blocks);
  df_set_blocks (df, blocks);
  df_analyze (df);
  df_analyze (df);
  BITMAP_FREE (blocks);
  BITMAP_FREE (blocks);
}
}
 
 
/* Creates a new invariant for definition DEF in INSN, depending on invariants
/* Creates a new invariant for definition DEF in INSN, depending on invariants
   in DEPENDS_ON.  ALWAYS_EXECUTED is true if the insn is always executed,
   in DEPENDS_ON.  ALWAYS_EXECUTED is true if the insn is always executed,
   unless the program ends due to a function call.  The newly created invariant
   unless the program ends due to a function call.  The newly created invariant
   is returned.  */
   is returned.  */
 
 
static struct invariant *
static struct invariant *
create_new_invariant (struct def *def, rtx insn, bitmap depends_on,
create_new_invariant (struct def *def, rtx insn, bitmap depends_on,
                      bool always_executed)
                      bool always_executed)
{
{
  struct invariant *inv = XNEW (struct invariant);
  struct invariant *inv = XNEW (struct invariant);
  rtx set = single_set (insn);
  rtx set = single_set (insn);
 
 
  inv->def = def;
  inv->def = def;
  inv->always_executed = always_executed;
  inv->always_executed = always_executed;
  inv->depends_on = depends_on;
  inv->depends_on = depends_on;
 
 
  /* If the set is simple, usually by moving it we move the whole store out of
  /* If the set is simple, usually by moving it we move the whole store out of
     the loop.  Otherwise we save only cost of the computation.  */
     the loop.  Otherwise we save only cost of the computation.  */
  if (def)
  if (def)
    inv->cost = rtx_cost (set, SET);
    inv->cost = rtx_cost (set, SET);
  else
  else
    inv->cost = rtx_cost (SET_SRC (set), SET);
    inv->cost = rtx_cost (SET_SRC (set), SET);
 
 
  inv->move = false;
  inv->move = false;
  inv->reg = NULL_RTX;
  inv->reg = NULL_RTX;
  inv->stamp = 0;
  inv->stamp = 0;
  inv->insn = insn;
  inv->insn = insn;
 
 
  inv->invno = VEC_length (invariant_p, invariants);
  inv->invno = VEC_length (invariant_p, invariants);
  inv->eqto = ~0u;
  inv->eqto = ~0u;
  if (def)
  if (def)
    def->invno = inv->invno;
    def->invno = inv->invno;
  VEC_safe_push (invariant_p, heap, invariants, inv);
  VEC_safe_push (invariant_p, heap, invariants, inv);
 
 
  if (dump_file)
  if (dump_file)
    {
    {
      fprintf (dump_file,
      fprintf (dump_file,
               "Set in insn %d is invariant (%d), cost %d, depends on ",
               "Set in insn %d is invariant (%d), cost %d, depends on ",
               INSN_UID (insn), inv->invno, inv->cost);
               INSN_UID (insn), inv->invno, inv->cost);
      dump_bitmap (dump_file, inv->depends_on);
      dump_bitmap (dump_file, inv->depends_on);
    }
    }
 
 
  return inv;
  return inv;
}
}
 
 
/* Record USE at DEF.  */
/* Record USE at DEF.  */
 
 
static void
static void
record_use (struct def *def, rtx *use, rtx insn)
record_use (struct def *def, rtx *use, rtx insn)
{
{
  struct use *u = XNEW (struct use);
  struct use *u = XNEW (struct use);
 
 
  if (GET_CODE (*use) == SUBREG)
  if (GET_CODE (*use) == SUBREG)
    use = &SUBREG_REG (*use);
    use = &SUBREG_REG (*use);
  gcc_assert (REG_P (*use));
  gcc_assert (REG_P (*use));
 
 
  u->pos = use;
  u->pos = use;
  u->insn = insn;
  u->insn = insn;
  u->next = def->uses;
  u->next = def->uses;
  def->uses = u;
  def->uses = u;
  def->n_uses++;
  def->n_uses++;
}
}
 
 
/* Finds the invariants INSN depends on and store them to the DEPENDS_ON
/* Finds the invariants INSN depends on and store them to the DEPENDS_ON
   bitmap.  Returns true if all dependencies of INSN are known to be
   bitmap.  Returns true if all dependencies of INSN are known to be
   loop invariants, false otherwise.  */
   loop invariants, false otherwise.  */
 
 
static bool
static bool
check_dependencies (rtx insn, bitmap depends_on)
check_dependencies (rtx insn, bitmap depends_on)
{
{
  struct df_link *defs;
  struct df_link *defs;
  struct df_ref *use, *def;
  struct df_ref *use, *def;
  basic_block bb = BLOCK_FOR_INSN (insn), def_bb;
  basic_block bb = BLOCK_FOR_INSN (insn), def_bb;
  struct def *def_data;
  struct def *def_data;
  struct invariant *inv;
  struct invariant *inv;
 
 
  for (use = DF_INSN_GET (df, insn)->uses; use; use = use->next_ref)
  for (use = DF_INSN_GET (df, insn)->uses; use; use = use->next_ref)
    {
    {
      if (use->flags & DF_REF_READ_WRITE)
      if (use->flags & DF_REF_READ_WRITE)
        return false;
        return false;
 
 
      defs = DF_REF_CHAIN (use);
      defs = DF_REF_CHAIN (use);
      if (!defs)
      if (!defs)
        continue;
        continue;
 
 
      if (defs->next)
      if (defs->next)
        return false;
        return false;
 
 
      def = defs->ref;
      def = defs->ref;
      inv = DF_REF_DATA (def);
      inv = DF_REF_DATA (def);
      if (!inv)
      if (!inv)
        return false;
        return false;
 
 
      def_data = inv->def;
      def_data = inv->def;
      gcc_assert (def_data != NULL);
      gcc_assert (def_data != NULL);
 
 
      def_bb = DF_REF_BB (def);
      def_bb = DF_REF_BB (def);
      /* Note that in case bb == def_bb, we know that the definition dominates
      /* Note that in case bb == def_bb, we know that the definition dominates
         insn, because def has DF_REF_DATA defined and we process the insns
         insn, because def has DF_REF_DATA defined and we process the insns
         in the basic block bb sequentially.  */
         in the basic block bb sequentially.  */
      if (!dominated_by_p (CDI_DOMINATORS, bb, def_bb))
      if (!dominated_by_p (CDI_DOMINATORS, bb, def_bb))
        return false;
        return false;
 
 
      bitmap_set_bit (depends_on, def_data->invno);
      bitmap_set_bit (depends_on, def_data->invno);
    }
    }
 
 
  return true;
  return true;
}
}
 
 
/* Finds invariant in INSN.  ALWAYS_REACHED is true if the insn is always
/* Finds invariant in INSN.  ALWAYS_REACHED is true if the insn is always
   executed.  ALWAYS_EXECUTED is true if the insn is always executed,
   executed.  ALWAYS_EXECUTED is true if the insn is always executed,
   unless the program ends due to a function call.  */
   unless the program ends due to a function call.  */
 
 
static void
static void
find_invariant_insn (rtx insn, bool always_reached, bool always_executed)
find_invariant_insn (rtx insn, bool always_reached, bool always_executed)
{
{
  struct df_ref *ref;
  struct df_ref *ref;
  struct def *def;
  struct def *def;
  bitmap depends_on;
  bitmap depends_on;
  rtx set, dest;
  rtx set, dest;
  bool simple = true;
  bool simple = true;
  struct invariant *inv;
  struct invariant *inv;
 
 
  /* Until we get rid of LIBCALLS.  */
  /* Until we get rid of LIBCALLS.  */
  if (find_reg_note (insn, REG_RETVAL, NULL_RTX)
  if (find_reg_note (insn, REG_RETVAL, NULL_RTX)
      || find_reg_note (insn, REG_LIBCALL, NULL_RTX)
      || find_reg_note (insn, REG_LIBCALL, NULL_RTX)
      || find_reg_note (insn, REG_NO_CONFLICT, NULL_RTX))
      || find_reg_note (insn, REG_NO_CONFLICT, NULL_RTX))
    return;
    return;
 
 
#ifdef HAVE_cc0
#ifdef HAVE_cc0
  /* We can't move a CC0 setter without the user.  */
  /* We can't move a CC0 setter without the user.  */
  if (sets_cc0_p (insn))
  if (sets_cc0_p (insn))
    return;
    return;
#endif
#endif
 
 
  set = single_set (insn);
  set = single_set (insn);
  if (!set)
  if (!set)
    return;
    return;
  dest = SET_DEST (set);
  dest = SET_DEST (set);
 
 
  if (!REG_P (dest)
  if (!REG_P (dest)
      || HARD_REGISTER_P (dest))
      || HARD_REGISTER_P (dest))
    simple = false;
    simple = false;
 
 
  if (!may_assign_reg_p (SET_DEST (set))
  if (!may_assign_reg_p (SET_DEST (set))
      || !check_maybe_invariant (SET_SRC (set)))
      || !check_maybe_invariant (SET_SRC (set)))
    return;
    return;
 
 
  /* If the insn can throw exception, we cannot move it at all without changing
  /* If the insn can throw exception, we cannot move it at all without changing
     cfg.  */
     cfg.  */
  if (can_throw_internal (insn))
  if (can_throw_internal (insn))
    return;
    return;
 
 
  /* We cannot make trapping insn executed, unless it was executed before.  */
  /* We cannot make trapping insn executed, unless it was executed before.  */
  if (may_trap_after_code_motion_p (PATTERN (insn)) && !always_reached)
  if (may_trap_after_code_motion_p (PATTERN (insn)) && !always_reached)
    return;
    return;
 
 
  depends_on = BITMAP_ALLOC (NULL);
  depends_on = BITMAP_ALLOC (NULL);
  if (!check_dependencies (insn, depends_on))
  if (!check_dependencies (insn, depends_on))
    {
    {
      BITMAP_FREE (depends_on);
      BITMAP_FREE (depends_on);
      return;
      return;
    }
    }
 
 
  if (simple)
  if (simple)
    def = XCNEW (struct def);
    def = XCNEW (struct def);
  else
  else
    def = NULL;
    def = NULL;
 
 
  inv = create_new_invariant (def, insn, depends_on, always_executed);
  inv = create_new_invariant (def, insn, depends_on, always_executed);
 
 
  if (simple)
  if (simple)
    {
    {
      ref = df_find_def (df, insn, dest);
      ref = df_find_def (df, insn, dest);
      DF_REF_DATA (ref) = inv;
      DF_REF_DATA (ref) = inv;
    }
    }
}
}
 
 
/* Record registers used in INSN that have a unique invariant definition.  */
/* Record registers used in INSN that have a unique invariant definition.  */
 
 
static void
static void
record_uses (rtx insn)
record_uses (rtx insn)
{
{
  struct df_ref *use;
  struct df_ref *use;
  struct invariant *inv;
  struct invariant *inv;
 
 
  for (use = DF_INSN_GET (df, insn)->uses; use; use = use->next_ref)
  for (use = DF_INSN_GET (df, insn)->uses; use; use = use->next_ref)
    {
    {
      inv = invariant_for_use (use);
      inv = invariant_for_use (use);
      if (inv)
      if (inv)
        record_use (inv->def, DF_REF_LOC (use), DF_REF_INSN (use));
        record_use (inv->def, DF_REF_LOC (use), DF_REF_INSN (use));
    }
    }
}
}
 
 
/* Finds invariants in INSN.  ALWAYS_REACHED is true if the insn is always
/* Finds invariants in INSN.  ALWAYS_REACHED is true if the insn is always
   executed.  ALWAYS_EXECUTED is true if the insn is always executed,
   executed.  ALWAYS_EXECUTED is true if the insn is always executed,
   unless the program ends due to a function call.  */
   unless the program ends due to a function call.  */
 
 
static void
static void
find_invariants_insn (rtx insn, bool always_reached, bool always_executed)
find_invariants_insn (rtx insn, bool always_reached, bool always_executed)
{
{
  find_invariant_insn (insn, always_reached, always_executed);
  find_invariant_insn (insn, always_reached, always_executed);
  record_uses (insn);
  record_uses (insn);
}
}
 
 
/* Finds invariants in basic block BB.  ALWAYS_REACHED is true if the
/* Finds invariants in basic block BB.  ALWAYS_REACHED is true if the
   basic block is always executed.  ALWAYS_EXECUTED is true if the basic
   basic block is always executed.  ALWAYS_EXECUTED is true if the basic
   block is always executed, unless the program ends due to a function
   block is always executed, unless the program ends due to a function
   call.  */
   call.  */
 
 
static void
static void
find_invariants_bb (basic_block bb, bool always_reached, bool always_executed)
find_invariants_bb (basic_block bb, bool always_reached, bool always_executed)
{
{
  rtx insn;
  rtx insn;
 
 
  FOR_BB_INSNS (bb, insn)
  FOR_BB_INSNS (bb, insn)
    {
    {
      if (!INSN_P (insn))
      if (!INSN_P (insn))
        continue;
        continue;
 
 
      find_invariants_insn (insn, always_reached, always_executed);
      find_invariants_insn (insn, always_reached, always_executed);
 
 
      if (always_reached
      if (always_reached
          && CALL_P (insn)
          && CALL_P (insn)
          && !CONST_OR_PURE_CALL_P (insn))
          && !CONST_OR_PURE_CALL_P (insn))
        always_reached = false;
        always_reached = false;
    }
    }
}
}
 
 
/* Finds invariants in LOOP with body BODY.  ALWAYS_REACHED is the bitmap of
/* Finds invariants in LOOP with body BODY.  ALWAYS_REACHED is the bitmap of
   basic blocks in BODY that are always executed.  ALWAYS_EXECUTED is the
   basic blocks in BODY that are always executed.  ALWAYS_EXECUTED is the
   bitmap of basic blocks in BODY that are always executed unless the program
   bitmap of basic blocks in BODY that are always executed unless the program
   ends due to a function call.  */
   ends due to a function call.  */
 
 
static void
static void
find_invariants_body (struct loop *loop, basic_block *body,
find_invariants_body (struct loop *loop, basic_block *body,
                      bitmap always_reached, bitmap always_executed)
                      bitmap always_reached, bitmap always_executed)
{
{
  unsigned i;
  unsigned i;
 
 
  for (i = 0; i < loop->num_nodes; i++)
  for (i = 0; i < loop->num_nodes; i++)
    find_invariants_bb (body[i],
    find_invariants_bb (body[i],
                        bitmap_bit_p (always_reached, i),
                        bitmap_bit_p (always_reached, i),
                        bitmap_bit_p (always_executed, i));
                        bitmap_bit_p (always_executed, i));
}
}
 
 
/* Finds invariants in LOOP.  */
/* Finds invariants in LOOP.  */
 
 
static void
static void
find_invariants (struct loop *loop)
find_invariants (struct loop *loop)
{
{
  bitmap may_exit = BITMAP_ALLOC (NULL);
  bitmap may_exit = BITMAP_ALLOC (NULL);
  bitmap always_reached = BITMAP_ALLOC (NULL);
  bitmap always_reached = BITMAP_ALLOC (NULL);
  bitmap has_exit = BITMAP_ALLOC (NULL);
  bitmap has_exit = BITMAP_ALLOC (NULL);
  bitmap always_executed = BITMAP_ALLOC (NULL);
  bitmap always_executed = BITMAP_ALLOC (NULL);
  basic_block *body = get_loop_body_in_dom_order (loop);
  basic_block *body = get_loop_body_in_dom_order (loop);
 
 
  find_exits (loop, body, may_exit, has_exit);
  find_exits (loop, body, may_exit, has_exit);
  compute_always_reached (loop, body, may_exit, always_reached);
  compute_always_reached (loop, body, may_exit, always_reached);
  compute_always_reached (loop, body, has_exit, always_executed);
  compute_always_reached (loop, body, has_exit, always_executed);
 
 
  find_defs (loop, body);
  find_defs (loop, body);
  find_invariants_body (loop, body, always_reached, always_executed);
  find_invariants_body (loop, body, always_reached, always_executed);
  merge_identical_invariants ();
  merge_identical_invariants ();
 
 
  BITMAP_FREE (always_reached);
  BITMAP_FREE (always_reached);
  BITMAP_FREE (always_executed);
  BITMAP_FREE (always_executed);
  BITMAP_FREE (may_exit);
  BITMAP_FREE (may_exit);
  BITMAP_FREE (has_exit);
  BITMAP_FREE (has_exit);
  free (body);
  free (body);
}
}
 
 
/* Frees a list of uses USE.  */
/* Frees a list of uses USE.  */
 
 
static void
static void
free_use_list (struct use *use)
free_use_list (struct use *use)
{
{
  struct use *next;
  struct use *next;
 
 
  for (; use; use = next)
  for (; use; use = next)
    {
    {
      next = use->next;
      next = use->next;
      free (use);
      free (use);
    }
    }
}
}
 
 
/* Calculates cost and number of registers needed for moving invariant INV
/* Calculates cost and number of registers needed for moving invariant INV
   out of the loop and stores them to *COST and *REGS_NEEDED.  */
   out of the loop and stores them to *COST and *REGS_NEEDED.  */
 
 
static void
static void
get_inv_cost (struct invariant *inv, int *comp_cost, unsigned *regs_needed)
get_inv_cost (struct invariant *inv, int *comp_cost, unsigned *regs_needed)
{
{
  int acomp_cost;
  int acomp_cost;
  unsigned aregs_needed;
  unsigned aregs_needed;
  unsigned depno;
  unsigned depno;
  struct invariant *dep;
  struct invariant *dep;
  bitmap_iterator bi;
  bitmap_iterator bi;
 
 
  /* Find the representative of the class of the equivalent invariants.  */
  /* Find the representative of the class of the equivalent invariants.  */
  inv = VEC_index (invariant_p, invariants, inv->eqto);
  inv = VEC_index (invariant_p, invariants, inv->eqto);
 
 
  *comp_cost = 0;
  *comp_cost = 0;
  *regs_needed = 0;
  *regs_needed = 0;
  if (inv->move
  if (inv->move
      || inv->stamp == actual_stamp)
      || inv->stamp == actual_stamp)
    return;
    return;
  inv->stamp = actual_stamp;
  inv->stamp = actual_stamp;
 
 
  (*regs_needed)++;
  (*regs_needed)++;
  (*comp_cost) += inv->cost;
  (*comp_cost) += inv->cost;
 
 
#ifdef STACK_REGS
#ifdef STACK_REGS
  {
  {
    /* Hoisting constant pool constants into stack regs may cost more than
    /* Hoisting constant pool constants into stack regs may cost more than
       just single register.  On x87, the balance is affected both by the
       just single register.  On x87, the balance is affected both by the
       small number of FP registers, and by its register stack organization,
       small number of FP registers, and by its register stack organization,
       that forces us to add compensation code in and around the loop to
       that forces us to add compensation code in and around the loop to
       shuffle the operands to the top of stack before use, and pop them
       shuffle the operands to the top of stack before use, and pop them
       from the stack after the loop finishes.
       from the stack after the loop finishes.
 
 
       To model this effect, we increase the number of registers needed for
       To model this effect, we increase the number of registers needed for
       stack registers by two: one register push, and one register pop.
       stack registers by two: one register push, and one register pop.
       This usually has the effect that FP constant loads from the constant
       This usually has the effect that FP constant loads from the constant
       pool are not moved out of the loop.
       pool are not moved out of the loop.
 
 
       Note that this also means that dependent invariants can not be moved.
       Note that this also means that dependent invariants can not be moved.
       However, the primary purpose of this pass is to move loop invariant
       However, the primary purpose of this pass is to move loop invariant
       address arithmetic out of loops, and address arithmetic that depends
       address arithmetic out of loops, and address arithmetic that depends
       on floating point constants is unlikely to ever occur.  */
       on floating point constants is unlikely to ever occur.  */
    rtx set = single_set (inv->insn);
    rtx set = single_set (inv->insn);
    if (set
    if (set
       && IS_STACK_MODE (GET_MODE (SET_SRC (set)))
       && IS_STACK_MODE (GET_MODE (SET_SRC (set)))
       && constant_pool_constant_p (SET_SRC (set)))
       && constant_pool_constant_p (SET_SRC (set)))
      (*regs_needed) += 2;
      (*regs_needed) += 2;
  }
  }
#endif
#endif
 
 
  EXECUTE_IF_SET_IN_BITMAP (inv->depends_on, 0, depno, bi)
  EXECUTE_IF_SET_IN_BITMAP (inv->depends_on, 0, depno, bi)
    {
    {
      dep = VEC_index (invariant_p, invariants, depno);
      dep = VEC_index (invariant_p, invariants, depno);
 
 
      get_inv_cost (dep, &acomp_cost, &aregs_needed);
      get_inv_cost (dep, &acomp_cost, &aregs_needed);
 
 
      if (aregs_needed
      if (aregs_needed
          /* We need to check always_executed, since if the original value of
          /* We need to check always_executed, since if the original value of
             the invariant may be preserved, we may need to keep it in a
             the invariant may be preserved, we may need to keep it in a
             separate register.  TODO check whether the register has an
             separate register.  TODO check whether the register has an
             use outside of the loop.  */
             use outside of the loop.  */
          && dep->always_executed
          && dep->always_executed
          && !dep->def->uses->next)
          && !dep->def->uses->next)
        {
        {
          /* If this is a single use, after moving the dependency we will not
          /* If this is a single use, after moving the dependency we will not
             need a new register.  */
             need a new register.  */
          aregs_needed--;
          aregs_needed--;
        }
        }
 
 
      (*regs_needed) += aregs_needed;
      (*regs_needed) += aregs_needed;
      (*comp_cost) += acomp_cost;
      (*comp_cost) += acomp_cost;
    }
    }
}
}
 
 
/* Calculates gain for eliminating invariant INV.  REGS_USED is the number
/* Calculates gain for eliminating invariant INV.  REGS_USED is the number
   of registers used in the loop, N_INV_USES is the number of uses of
   of registers used in the loop, N_INV_USES is the number of uses of
   invariants, NEW_REGS is the number of new variables already added due to
   invariants, NEW_REGS is the number of new variables already added due to
   the invariant motion.  The number of registers needed for it is stored in
   the invariant motion.  The number of registers needed for it is stored in
   *REGS_NEEDED.  */
   *REGS_NEEDED.  */
 
 
static int
static int
gain_for_invariant (struct invariant *inv, unsigned *regs_needed,
gain_for_invariant (struct invariant *inv, unsigned *regs_needed,
                    unsigned new_regs, unsigned regs_used, unsigned n_inv_uses)
                    unsigned new_regs, unsigned regs_used, unsigned n_inv_uses)
{
{
  int comp_cost, size_cost;
  int comp_cost, size_cost;
 
 
  get_inv_cost (inv, &comp_cost, regs_needed);
  get_inv_cost (inv, &comp_cost, regs_needed);
  actual_stamp++;
  actual_stamp++;
 
 
  size_cost = (global_cost_for_size (new_regs + *regs_needed,
  size_cost = (global_cost_for_size (new_regs + *regs_needed,
                                     regs_used, n_inv_uses)
                                     regs_used, n_inv_uses)
               - global_cost_for_size (new_regs, regs_used, n_inv_uses));
               - global_cost_for_size (new_regs, regs_used, n_inv_uses));
 
 
  return comp_cost - size_cost;
  return comp_cost - size_cost;
}
}
 
 
/* Finds invariant with best gain for moving.  Returns the gain, stores
/* Finds invariant with best gain for moving.  Returns the gain, stores
   the invariant in *BEST and number of registers needed for it to
   the invariant in *BEST and number of registers needed for it to
   *REGS_NEEDED.  REGS_USED is the number of registers used in
   *REGS_NEEDED.  REGS_USED is the number of registers used in
   the loop, N_INV_USES is the number of uses of invariants.  NEW_REGS
   the loop, N_INV_USES is the number of uses of invariants.  NEW_REGS
   is the number of new variables already added due to invariant motion.  */
   is the number of new variables already added due to invariant motion.  */
 
 
static int
static int
best_gain_for_invariant (struct invariant **best, unsigned *regs_needed,
best_gain_for_invariant (struct invariant **best, unsigned *regs_needed,
                         unsigned new_regs, unsigned regs_used,
                         unsigned new_regs, unsigned regs_used,
                         unsigned n_inv_uses)
                         unsigned n_inv_uses)
{
{
  struct invariant *inv;
  struct invariant *inv;
  int gain = 0, again;
  int gain = 0, again;
  unsigned aregs_needed, invno;
  unsigned aregs_needed, invno;
 
 
  for (invno = 0; VEC_iterate (invariant_p, invariants, invno, inv); invno++)
  for (invno = 0; VEC_iterate (invariant_p, invariants, invno, inv); invno++)
    {
    {
      if (inv->move)
      if (inv->move)
        continue;
        continue;
 
 
      /* Only consider the "representatives" of equivalent invariants.  */
      /* Only consider the "representatives" of equivalent invariants.  */
      if (inv->eqto != inv->invno)
      if (inv->eqto != inv->invno)
        continue;
        continue;
 
 
      again = gain_for_invariant (inv, &aregs_needed,
      again = gain_for_invariant (inv, &aregs_needed,
                                  new_regs, regs_used, n_inv_uses);
                                  new_regs, regs_used, n_inv_uses);
      if (again > gain)
      if (again > gain)
        {
        {
          gain = again;
          gain = again;
          *best = inv;
          *best = inv;
          *regs_needed = aregs_needed;
          *regs_needed = aregs_needed;
        }
        }
    }
    }
 
 
  return gain;
  return gain;
}
}
 
 
/* Marks invariant INVNO and all its dependencies for moving.  */
/* Marks invariant INVNO and all its dependencies for moving.  */
 
 
static void
static void
set_move_mark (unsigned invno)
set_move_mark (unsigned invno)
{
{
  struct invariant *inv = VEC_index (invariant_p, invariants, invno);
  struct invariant *inv = VEC_index (invariant_p, invariants, invno);
  bitmap_iterator bi;
  bitmap_iterator bi;
 
 
  /* Find the representative of the class of the equivalent invariants.  */
  /* Find the representative of the class of the equivalent invariants.  */
  inv = VEC_index (invariant_p, invariants, inv->eqto);
  inv = VEC_index (invariant_p, invariants, inv->eqto);
 
 
  if (inv->move)
  if (inv->move)
    return;
    return;
  inv->move = true;
  inv->move = true;
 
 
  if (dump_file)
  if (dump_file)
    fprintf (dump_file, "Decided to move invariant %d\n", invno);
    fprintf (dump_file, "Decided to move invariant %d\n", invno);
 
 
  EXECUTE_IF_SET_IN_BITMAP (inv->depends_on, 0, invno, bi)
  EXECUTE_IF_SET_IN_BITMAP (inv->depends_on, 0, invno, bi)
    {
    {
      set_move_mark (invno);
      set_move_mark (invno);
    }
    }
}
}
 
 
/* Determines which invariants to move.  */
/* Determines which invariants to move.  */
 
 
static void
static void
find_invariants_to_move (void)
find_invariants_to_move (void)
{
{
  unsigned i, regs_used, n_inv_uses, regs_needed = 0, new_regs;
  unsigned i, regs_used, n_inv_uses, regs_needed = 0, new_regs;
  struct invariant *inv = NULL;
  struct invariant *inv = NULL;
  unsigned int n_regs = DF_REG_SIZE (df);
  unsigned int n_regs = DF_REG_SIZE (df);
 
 
  if (!VEC_length (invariant_p, invariants))
  if (!VEC_length (invariant_p, invariants))
    return;
    return;
 
 
  /* Now something slightly more involved.  First estimate the number of used
  /* Now something slightly more involved.  First estimate the number of used
     registers.  */
     registers.  */
  n_inv_uses = 0;
  n_inv_uses = 0;
 
 
  /* We do not really do a good job in this estimation; put some initial bound
  /* We do not really do a good job in this estimation; put some initial bound
     here to stand for induction variables etc. that we do not detect.  */
     here to stand for induction variables etc. that we do not detect.  */
  regs_used = 2;
  regs_used = 2;
 
 
  for (i = 0; i < n_regs; i++)
  for (i = 0; i < n_regs; i++)
    {
    {
      if (!DF_REGNO_FIRST_DEF (df, i) && DF_REGNO_LAST_USE (df, i))
      if (!DF_REGNO_FIRST_DEF (df, i) && DF_REGNO_LAST_USE (df, i))
        {
        {
          /* This is a value that is used but not changed inside loop.  */
          /* This is a value that is used but not changed inside loop.  */
          regs_used++;
          regs_used++;
        }
        }
    }
    }
 
 
  for (i = 0; VEC_iterate (invariant_p, invariants, i, inv); i++)
  for (i = 0; VEC_iterate (invariant_p, invariants, i, inv); i++)
    {
    {
      if (inv->def)
      if (inv->def)
        n_inv_uses += inv->def->n_uses;
        n_inv_uses += inv->def->n_uses;
    }
    }
 
 
  new_regs = 0;
  new_regs = 0;
  while (best_gain_for_invariant (&inv, &regs_needed,
  while (best_gain_for_invariant (&inv, &regs_needed,
                                  new_regs, regs_used, n_inv_uses) > 0)
                                  new_regs, regs_used, n_inv_uses) > 0)
    {
    {
      set_move_mark (inv->invno);
      set_move_mark (inv->invno);
      new_regs += regs_needed;
      new_regs += regs_needed;
    }
    }
}
}
 
 
/* Returns true if all insns in SEQ are valid.  */
/* Returns true if all insns in SEQ are valid.  */
 
 
static bool
static bool
seq_insns_valid_p (rtx seq)
seq_insns_valid_p (rtx seq)
{
{
  rtx x;
  rtx x;
 
 
  for (x = seq; x; x = NEXT_INSN (x))
  for (x = seq; x; x = NEXT_INSN (x))
    if (insn_invalid_p (x))
    if (insn_invalid_p (x))
      return false;
      return false;
 
 
  return true;
  return true;
}
}
 
 
/* Move invariant INVNO out of the LOOP.  Returns true if this succeeds, false
/* Move invariant INVNO out of the LOOP.  Returns true if this succeeds, false
   otherwise.  */
   otherwise.  */
 
 
static bool
static bool
move_invariant_reg (struct loop *loop, unsigned invno)
move_invariant_reg (struct loop *loop, unsigned invno)
{
{
  struct invariant *inv = VEC_index (invariant_p, invariants, invno);
  struct invariant *inv = VEC_index (invariant_p, invariants, invno);
  struct invariant *repr = VEC_index (invariant_p, invariants, inv->eqto);
  struct invariant *repr = VEC_index (invariant_p, invariants, inv->eqto);
  unsigned i;
  unsigned i;
  basic_block preheader = loop_preheader_edge (loop)->src;
  basic_block preheader = loop_preheader_edge (loop)->src;
  rtx reg, set, dest, seq, op;
  rtx reg, set, dest, seq, op;
  struct use *use;
  struct use *use;
  bitmap_iterator bi;
  bitmap_iterator bi;
 
 
  if (inv->reg)
  if (inv->reg)
    return true;
    return true;
  if (!repr->move)
  if (!repr->move)
    return false;
    return false;
 
 
  /* If this is a representative of the class of equivalent invariants,
  /* If this is a representative of the class of equivalent invariants,
     really move the invariant.  Otherwise just replace its use with
     really move the invariant.  Otherwise just replace its use with
     the register used for the representative.  */
     the register used for the representative.  */
  if (inv == repr)
  if (inv == repr)
    {
    {
      if (inv->depends_on)
      if (inv->depends_on)
        {
        {
          EXECUTE_IF_SET_IN_BITMAP (inv->depends_on, 0, i, bi)
          EXECUTE_IF_SET_IN_BITMAP (inv->depends_on, 0, i, bi)
            {
            {
              if (!move_invariant_reg (loop, i))
              if (!move_invariant_reg (loop, i))
                goto fail;
                goto fail;
            }
            }
        }
        }
 
 
      /* Move the set out of the loop.  If the set is always executed (we could
      /* Move the set out of the loop.  If the set is always executed (we could
         omit this condition if we know that the register is unused outside of the
         omit this condition if we know that the register is unused outside of the
         loop, but it does not seem worth finding out) and it has no uses that
         loop, but it does not seem worth finding out) and it has no uses that
         would not be dominated by it, we may just move it (TODO).  Otherwise we
         would not be dominated by it, we may just move it (TODO).  Otherwise we
         need to create a temporary register.  */
         need to create a temporary register.  */
      set = single_set (inv->insn);
      set = single_set (inv->insn);
      dest = SET_DEST (set);
      dest = SET_DEST (set);
      reg = gen_reg_rtx (GET_MODE (dest));
      reg = gen_reg_rtx (GET_MODE (dest));
 
 
      /* If the SET_DEST of the invariant insn is a pseudo, we can just move
      /* If the SET_DEST of the invariant insn is a pseudo, we can just move
         the insn out of the loop.  Otherwise, we have to use gen_move_insn
         the insn out of the loop.  Otherwise, we have to use gen_move_insn
         to let emit_move_insn produce a valid instruction stream.  */
         to let emit_move_insn produce a valid instruction stream.  */
      if (REG_P (dest) && !HARD_REGISTER_P (dest))
      if (REG_P (dest) && !HARD_REGISTER_P (dest))
        {
        {
          emit_insn_after (gen_move_insn (dest, reg), inv->insn);
          emit_insn_after (gen_move_insn (dest, reg), inv->insn);
          SET_DEST (set) = reg;
          SET_DEST (set) = reg;
          reorder_insns (inv->insn, inv->insn, BB_END (preheader));
          reorder_insns (inv->insn, inv->insn, BB_END (preheader));
        }
        }
      else
      else
        {
        {
          start_sequence ();
          start_sequence ();
          op = force_operand (SET_SRC (set), reg);
          op = force_operand (SET_SRC (set), reg);
          if (!op)
          if (!op)
            {
            {
              end_sequence ();
              end_sequence ();
              goto fail;
              goto fail;
            }
            }
          if (op != reg)
          if (op != reg)
            emit_move_insn (reg, op);
            emit_move_insn (reg, op);
          seq = get_insns ();
          seq = get_insns ();
          end_sequence ();
          end_sequence ();
 
 
          if (!seq_insns_valid_p (seq))
          if (!seq_insns_valid_p (seq))
            goto fail;
            goto fail;
          emit_insn_after (seq, BB_END (preheader));
          emit_insn_after (seq, BB_END (preheader));
 
 
          emit_insn_after (gen_move_insn (dest, reg), inv->insn);
          emit_insn_after (gen_move_insn (dest, reg), inv->insn);
          delete_insn (inv->insn);
          delete_insn (inv->insn);
        }
        }
    }
    }
  else
  else
    {
    {
      if (!move_invariant_reg (loop, repr->invno))
      if (!move_invariant_reg (loop, repr->invno))
        goto fail;
        goto fail;
      reg = repr->reg;
      reg = repr->reg;
      set = single_set (inv->insn);
      set = single_set (inv->insn);
      emit_insn_after (gen_move_insn (SET_DEST (set), reg), inv->insn);
      emit_insn_after (gen_move_insn (SET_DEST (set), reg), inv->insn);
      delete_insn (inv->insn);
      delete_insn (inv->insn);
    }
    }
 
 
  inv->reg = reg;
  inv->reg = reg;
 
 
  /* Replace the uses we know to be dominated.  It saves work for copy
  /* Replace the uses we know to be dominated.  It saves work for copy
     propagation, and also it is necessary so that dependent invariants
     propagation, and also it is necessary so that dependent invariants
     are computed right.  */
     are computed right.  */
  if (inv->def)
  if (inv->def)
    {
    {
      for (use = inv->def->uses; use; use = use->next)
      for (use = inv->def->uses; use; use = use->next)
        *use->pos = reg;
        *use->pos = reg;
    }
    }
 
 
  return true;
  return true;
 
 
fail:
fail:
  /* If we failed, clear move flag, so that we do not try to move inv
  /* If we failed, clear move flag, so that we do not try to move inv
     again.  */
     again.  */
  if (dump_file)
  if (dump_file)
    fprintf (dump_file, "Failed to move invariant %d\n", invno);
    fprintf (dump_file, "Failed to move invariant %d\n", invno);
  inv->move = false;
  inv->move = false;
  inv->reg = NULL_RTX;
  inv->reg = NULL_RTX;
  return false;
  return false;
}
}
 
 
/* Move selected invariant out of the LOOP.  Newly created regs are marked
/* Move selected invariant out of the LOOP.  Newly created regs are marked
   in TEMPORARY_REGS.  */
   in TEMPORARY_REGS.  */
 
 
static void
static void
move_invariants (struct loop *loop)
move_invariants (struct loop *loop)
{
{
  struct invariant *inv;
  struct invariant *inv;
  unsigned i;
  unsigned i;
 
 
  for (i = 0; VEC_iterate (invariant_p, invariants, i, inv); i++)
  for (i = 0; VEC_iterate (invariant_p, invariants, i, inv); i++)
    move_invariant_reg (loop, i);
    move_invariant_reg (loop, i);
}
}
 
 
/* Initializes invariant motion data.  */
/* Initializes invariant motion data.  */
 
 
static void
static void
init_inv_motion_data (void)
init_inv_motion_data (void)
{
{
  actual_stamp = 1;
  actual_stamp = 1;
 
 
  invariants = VEC_alloc (invariant_p, heap, 100);
  invariants = VEC_alloc (invariant_p, heap, 100);
}
}
 
 
/* Frees the data allocated by invariant motion.  */
/* Frees the data allocated by invariant motion.  */
 
 
static void
static void
free_inv_motion_data (void)
free_inv_motion_data (void)
{
{
  unsigned i;
  unsigned i;
  struct def *def;
  struct def *def;
  struct invariant *inv;
  struct invariant *inv;
 
 
  for (i = 0; i < DF_DEFS_SIZE (df); i++)
  for (i = 0; i < DF_DEFS_SIZE (df); i++)
    {
    {
      struct df_ref * ref = DF_DEFS_GET (df, i);
      struct df_ref * ref = DF_DEFS_GET (df, i);
      if (!ref)
      if (!ref)
        continue;
        continue;
 
 
      inv = DF_REF_DATA (ref);
      inv = DF_REF_DATA (ref);
      if (!inv)
      if (!inv)
        continue;
        continue;
 
 
      def = inv->def;
      def = inv->def;
      gcc_assert (def != NULL);
      gcc_assert (def != NULL);
 
 
      free_use_list (def->uses);
      free_use_list (def->uses);
      free (def);
      free (def);
      DF_REF_DATA (ref) = NULL;
      DF_REF_DATA (ref) = NULL;
    }
    }
 
 
  for (i = 0; VEC_iterate (invariant_p, invariants, i, inv); i++)
  for (i = 0; VEC_iterate (invariant_p, invariants, i, inv); i++)
    {
    {
      BITMAP_FREE (inv->depends_on);
      BITMAP_FREE (inv->depends_on);
      free (inv);
      free (inv);
    }
    }
  VEC_free (invariant_p, heap, invariants);
  VEC_free (invariant_p, heap, invariants);
}
}
 
 
/* Move the invariants out of the LOOP.  */
/* Move the invariants out of the LOOP.  */
 
 
static void
static void
move_single_loop_invariants (struct loop *loop)
move_single_loop_invariants (struct loop *loop)
{
{
  init_inv_motion_data ();
  init_inv_motion_data ();
 
 
  find_invariants (loop);
  find_invariants (loop);
  find_invariants_to_move ();
  find_invariants_to_move ();
  move_invariants (loop);
  move_invariants (loop);
 
 
  free_inv_motion_data ();
  free_inv_motion_data ();
}
}
 
 
/* Releases the auxiliary data for LOOP.  */
/* Releases the auxiliary data for LOOP.  */
 
 
static void
static void
free_loop_data (struct loop *loop)
free_loop_data (struct loop *loop)
{
{
  struct loop_data *data = LOOP_DATA (loop);
  struct loop_data *data = LOOP_DATA (loop);
 
 
  free (data);
  free (data);
  loop->aux = NULL;
  loop->aux = NULL;
}
}
 
 
/* Move the invariants out of the LOOPS.  */
/* Move the invariants out of the LOOPS.  */
 
 
void
void
move_loop_invariants (struct loops *loops)
move_loop_invariants (struct loops *loops)
{
{
  struct loop *loop;
  struct loop *loop;
  unsigned i;
  unsigned i;
 
 
  df = df_init (DF_HARD_REGS | DF_EQUIV_NOTES);
  df = df_init (DF_HARD_REGS | DF_EQUIV_NOTES);
  df_chain_add_problem (df, DF_UD_CHAIN);
  df_chain_add_problem (df, DF_UD_CHAIN);
 
 
  /* Process the loops, innermost first.  */
  /* Process the loops, innermost first.  */
  loop = loops->tree_root;
  loop = loops->tree_root;
  while (loop->inner)
  while (loop->inner)
    loop = loop->inner;
    loop = loop->inner;
 
 
  while (loop != loops->tree_root)
  while (loop != loops->tree_root)
    {
    {
      move_single_loop_invariants (loop);
      move_single_loop_invariants (loop);
 
 
      if (loop->next)
      if (loop->next)
        {
        {
          loop = loop->next;
          loop = loop->next;
          while (loop->inner)
          while (loop->inner)
            loop = loop->inner;
            loop = loop->inner;
        }
        }
      else
      else
        loop = loop->outer;
        loop = loop->outer;
    }
    }
 
 
  for (i = 1; i < loops->num; i++)
  for (i = 1; i < loops->num; i++)
    if (loops->parray[i])
    if (loops->parray[i])
      free_loop_data (loops->parray[i]);
      free_loop_data (loops->parray[i]);
 
 
  df_finish (df);
  df_finish (df);
  df = NULL;
  df = NULL;
 
 
#ifdef ENABLE_CHECKING
#ifdef ENABLE_CHECKING
  verify_flow_info ();
  verify_flow_info ();
#endif
#endif
}
}
 
 

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