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[/] [openrisc/] [trunk/] [gnu-old/] [gcc-4.2.2/] [gcc/] [cselib.c] - Diff between revs 154 and 816

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/* Common subexpression elimination library for GNU compiler.
/* Common subexpression elimination library for GNU compiler.
   Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   1999, 2000, 2001, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
   1999, 2000, 2001, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
 
 
This file is part of GCC.
This file is part of GCC.
 
 
GCC is free software; you can redistribute it and/or modify it under
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
Software Foundation; either version 3, or (at your option) any later
version.
version.
 
 
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.
for more details.
 
 
You should have received a copy of the GNU General Public License
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3.  If not see
along with GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */
<http://www.gnu.org/licenses/>.  */
 
 
#include "config.h"
#include "config.h"
#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 "regs.h"
#include "regs.h"
#include "hard-reg-set.h"
#include "hard-reg-set.h"
#include "flags.h"
#include "flags.h"
#include "real.h"
#include "real.h"
#include "insn-config.h"
#include "insn-config.h"
#include "recog.h"
#include "recog.h"
#include "function.h"
#include "function.h"
#include "emit-rtl.h"
#include "emit-rtl.h"
#include "toplev.h"
#include "toplev.h"
#include "output.h"
#include "output.h"
#include "ggc.h"
#include "ggc.h"
#include "hashtab.h"
#include "hashtab.h"
#include "cselib.h"
#include "cselib.h"
#include "params.h"
#include "params.h"
#include "alloc-pool.h"
#include "alloc-pool.h"
#include "target.h"
#include "target.h"
 
 
static bool cselib_record_memory;
static bool cselib_record_memory;
static int entry_and_rtx_equal_p (const void *, const void *);
static int entry_and_rtx_equal_p (const void *, const void *);
static hashval_t get_value_hash (const void *);
static hashval_t get_value_hash (const void *);
static struct elt_list *new_elt_list (struct elt_list *, cselib_val *);
static struct elt_list *new_elt_list (struct elt_list *, cselib_val *);
static struct elt_loc_list *new_elt_loc_list (struct elt_loc_list *, rtx);
static struct elt_loc_list *new_elt_loc_list (struct elt_loc_list *, rtx);
static void unchain_one_value (cselib_val *);
static void unchain_one_value (cselib_val *);
static void unchain_one_elt_list (struct elt_list **);
static void unchain_one_elt_list (struct elt_list **);
static void unchain_one_elt_loc_list (struct elt_loc_list **);
static void unchain_one_elt_loc_list (struct elt_loc_list **);
static int discard_useless_locs (void **, void *);
static int discard_useless_locs (void **, void *);
static int discard_useless_values (void **, void *);
static int discard_useless_values (void **, void *);
static void remove_useless_values (void);
static void remove_useless_values (void);
static rtx wrap_constant (enum machine_mode, rtx);
static rtx wrap_constant (enum machine_mode, rtx);
static unsigned int cselib_hash_rtx (rtx, int);
static unsigned int cselib_hash_rtx (rtx, int);
static cselib_val *new_cselib_val (unsigned int, enum machine_mode);
static cselib_val *new_cselib_val (unsigned int, enum machine_mode);
static void add_mem_for_addr (cselib_val *, cselib_val *, rtx);
static void add_mem_for_addr (cselib_val *, cselib_val *, rtx);
static cselib_val *cselib_lookup_mem (rtx, int);
static cselib_val *cselib_lookup_mem (rtx, int);
static void cselib_invalidate_regno (unsigned int, enum machine_mode);
static void cselib_invalidate_regno (unsigned int, enum machine_mode);
static void cselib_invalidate_mem (rtx);
static void cselib_invalidate_mem (rtx);
static void cselib_record_set (rtx, cselib_val *, cselib_val *);
static void cselib_record_set (rtx, cselib_val *, cselib_val *);
static void cselib_record_sets (rtx);
static void cselib_record_sets (rtx);
 
 
/* There are three ways in which cselib can look up an rtx:
/* There are three ways in which cselib can look up an rtx:
   - for a REG, the reg_values table (which is indexed by regno) is used
   - for a REG, the reg_values table (which is indexed by regno) is used
   - for a MEM, we recursively look up its address and then follow the
   - for a MEM, we recursively look up its address and then follow the
     addr_list of that value
     addr_list of that value
   - for everything else, we compute a hash value and go through the hash
   - for everything else, we compute a hash value and go through the hash
     table.  Since different rtx's can still have the same hash value,
     table.  Since different rtx's can still have the same hash value,
     this involves walking the table entries for a given value and comparing
     this involves walking the table entries for a given value and comparing
     the locations of the entries with the rtx we are looking up.  */
     the locations of the entries with the rtx we are looking up.  */
 
 
/* A table that enables us to look up elts by their value.  */
/* A table that enables us to look up elts by their value.  */
static htab_t cselib_hash_table;
static htab_t cselib_hash_table;
 
 
/* This is a global so we don't have to pass this through every function.
/* This is a global so we don't have to pass this through every function.
   It is used in new_elt_loc_list to set SETTING_INSN.  */
   It is used in new_elt_loc_list to set SETTING_INSN.  */
static rtx cselib_current_insn;
static rtx cselib_current_insn;
static bool cselib_current_insn_in_libcall;
static bool cselib_current_insn_in_libcall;
 
 
/* Every new unknown value gets a unique number.  */
/* Every new unknown value gets a unique number.  */
static unsigned int next_unknown_value;
static unsigned int next_unknown_value;
 
 
/* The number of registers we had when the varrays were last resized.  */
/* The number of registers we had when the varrays were last resized.  */
static unsigned int cselib_nregs;
static unsigned int cselib_nregs;
 
 
/* Count values without known locations.  Whenever this grows too big, we
/* Count values without known locations.  Whenever this grows too big, we
   remove these useless values from the table.  */
   remove these useless values from the table.  */
static int n_useless_values;
static int n_useless_values;
 
 
/* Number of useless values before we remove them from the hash table.  */
/* Number of useless values before we remove them from the hash table.  */
#define MAX_USELESS_VALUES 32
#define MAX_USELESS_VALUES 32
 
 
/* This table maps from register number to values.  It does not
/* This table maps from register number to values.  It does not
   contain pointers to cselib_val structures, but rather elt_lists.
   contain pointers to cselib_val structures, but rather elt_lists.
   The purpose is to be able to refer to the same register in
   The purpose is to be able to refer to the same register in
   different modes.  The first element of the list defines the mode in
   different modes.  The first element of the list defines the mode in
   which the register was set; if the mode is unknown or the value is
   which the register was set; if the mode is unknown or the value is
   no longer valid in that mode, ELT will be NULL for the first
   no longer valid in that mode, ELT will be NULL for the first
   element.  */
   element.  */
static struct elt_list **reg_values;
static struct elt_list **reg_values;
static unsigned int reg_values_size;
static unsigned int reg_values_size;
#define REG_VALUES(i) reg_values[i]
#define REG_VALUES(i) reg_values[i]
 
 
/* The largest number of hard regs used by any entry added to the
/* The largest number of hard regs used by any entry added to the
   REG_VALUES table.  Cleared on each cselib_clear_table() invocation.  */
   REG_VALUES table.  Cleared on each cselib_clear_table() invocation.  */
static unsigned int max_value_regs;
static unsigned int max_value_regs;
 
 
/* Here the set of indices I with REG_VALUES(I) != 0 is saved.  This is used
/* Here the set of indices I with REG_VALUES(I) != 0 is saved.  This is used
   in cselib_clear_table() for fast emptying.  */
   in cselib_clear_table() for fast emptying.  */
static unsigned int *used_regs;
static unsigned int *used_regs;
static unsigned int n_used_regs;
static unsigned int n_used_regs;
 
 
/* We pass this to cselib_invalidate_mem to invalidate all of
/* We pass this to cselib_invalidate_mem to invalidate all of
   memory for a non-const call instruction.  */
   memory for a non-const call instruction.  */
static GTY(()) rtx callmem;
static GTY(()) rtx callmem;
 
 
/* Set by discard_useless_locs if it deleted the last location of any
/* Set by discard_useless_locs if it deleted the last location of any
   value.  */
   value.  */
static int values_became_useless;
static int values_became_useless;
 
 
/* Used as stop element of the containing_mem list so we can check
/* Used as stop element of the containing_mem list so we can check
   presence in the list by checking the next pointer.  */
   presence in the list by checking the next pointer.  */
static cselib_val dummy_val;
static cselib_val dummy_val;
 
 
/* Used to list all values that contain memory reference.
/* Used to list all values that contain memory reference.
   May or may not contain the useless values - the list is compacted
   May or may not contain the useless values - the list is compacted
   each time memory is invalidated.  */
   each time memory is invalidated.  */
static cselib_val *first_containing_mem = &dummy_val;
static cselib_val *first_containing_mem = &dummy_val;
static alloc_pool elt_loc_list_pool, elt_list_pool, cselib_val_pool, value_pool;
static alloc_pool elt_loc_list_pool, elt_list_pool, cselib_val_pool, value_pool;


 
 
/* Allocate a struct elt_list and fill in its two elements with the
/* Allocate a struct elt_list and fill in its two elements with the
   arguments.  */
   arguments.  */
 
 
static inline struct elt_list *
static inline struct elt_list *
new_elt_list (struct elt_list *next, cselib_val *elt)
new_elt_list (struct elt_list *next, cselib_val *elt)
{
{
  struct elt_list *el;
  struct elt_list *el;
  el = pool_alloc (elt_list_pool);
  el = pool_alloc (elt_list_pool);
  el->next = next;
  el->next = next;
  el->elt = elt;
  el->elt = elt;
  return el;
  return el;
}
}
 
 
/* Allocate a struct elt_loc_list and fill in its two elements with the
/* Allocate a struct elt_loc_list and fill in its two elements with the
   arguments.  */
   arguments.  */
 
 
static inline struct elt_loc_list *
static inline struct elt_loc_list *
new_elt_loc_list (struct elt_loc_list *next, rtx loc)
new_elt_loc_list (struct elt_loc_list *next, rtx loc)
{
{
  struct elt_loc_list *el;
  struct elt_loc_list *el;
  el = pool_alloc (elt_loc_list_pool);
  el = pool_alloc (elt_loc_list_pool);
  el->next = next;
  el->next = next;
  el->loc = loc;
  el->loc = loc;
  el->setting_insn = cselib_current_insn;
  el->setting_insn = cselib_current_insn;
  el->in_libcall = cselib_current_insn_in_libcall;
  el->in_libcall = cselib_current_insn_in_libcall;
  return el;
  return el;
}
}
 
 
/* The elt_list at *PL is no longer needed.  Unchain it and free its
/* The elt_list at *PL is no longer needed.  Unchain it and free its
   storage.  */
   storage.  */
 
 
static inline void
static inline void
unchain_one_elt_list (struct elt_list **pl)
unchain_one_elt_list (struct elt_list **pl)
{
{
  struct elt_list *l = *pl;
  struct elt_list *l = *pl;
 
 
  *pl = l->next;
  *pl = l->next;
  pool_free (elt_list_pool, l);
  pool_free (elt_list_pool, l);
}
}
 
 
/* Likewise for elt_loc_lists.  */
/* Likewise for elt_loc_lists.  */
 
 
static void
static void
unchain_one_elt_loc_list (struct elt_loc_list **pl)
unchain_one_elt_loc_list (struct elt_loc_list **pl)
{
{
  struct elt_loc_list *l = *pl;
  struct elt_loc_list *l = *pl;
 
 
  *pl = l->next;
  *pl = l->next;
  pool_free (elt_loc_list_pool, l);
  pool_free (elt_loc_list_pool, l);
}
}
 
 
/* Likewise for cselib_vals.  This also frees the addr_list associated with
/* Likewise for cselib_vals.  This also frees the addr_list associated with
   V.  */
   V.  */
 
 
static void
static void
unchain_one_value (cselib_val *v)
unchain_one_value (cselib_val *v)
{
{
  while (v->addr_list)
  while (v->addr_list)
    unchain_one_elt_list (&v->addr_list);
    unchain_one_elt_list (&v->addr_list);
 
 
  pool_free (cselib_val_pool, v);
  pool_free (cselib_val_pool, v);
}
}
 
 
/* Remove all entries from the hash table.  Also used during
/* Remove all entries from the hash table.  Also used during
   initialization.  If CLEAR_ALL isn't set, then only clear the entries
   initialization.  If CLEAR_ALL isn't set, then only clear the entries
   which are known to have been used.  */
   which are known to have been used.  */
 
 
void
void
cselib_clear_table (void)
cselib_clear_table (void)
{
{
  unsigned int i;
  unsigned int i;
 
 
  for (i = 0; i < n_used_regs; i++)
  for (i = 0; i < n_used_regs; i++)
    REG_VALUES (used_regs[i]) = 0;
    REG_VALUES (used_regs[i]) = 0;
 
 
  max_value_regs = 0;
  max_value_regs = 0;
 
 
  n_used_regs = 0;
  n_used_regs = 0;
 
 
  htab_empty (cselib_hash_table);
  htab_empty (cselib_hash_table);
 
 
  n_useless_values = 0;
  n_useless_values = 0;
 
 
  next_unknown_value = 0;
  next_unknown_value = 0;
 
 
  first_containing_mem = &dummy_val;
  first_containing_mem = &dummy_val;
}
}
 
 
/* The equality test for our hash table.  The first argument ENTRY is a table
/* The equality test for our hash table.  The first argument ENTRY is a table
   element (i.e. a cselib_val), while the second arg X is an rtx.  We know
   element (i.e. a cselib_val), while the second arg X is an rtx.  We know
   that all callers of htab_find_slot_with_hash will wrap CONST_INTs into a
   that all callers of htab_find_slot_with_hash will wrap CONST_INTs into a
   CONST of an appropriate mode.  */
   CONST of an appropriate mode.  */
 
 
static int
static int
entry_and_rtx_equal_p (const void *entry, const void *x_arg)
entry_and_rtx_equal_p (const void *entry, const void *x_arg)
{
{
  struct elt_loc_list *l;
  struct elt_loc_list *l;
  const cselib_val *v = (const cselib_val *) entry;
  const cselib_val *v = (const cselib_val *) entry;
  rtx x = (rtx) x_arg;
  rtx x = (rtx) x_arg;
  enum machine_mode mode = GET_MODE (x);
  enum machine_mode mode = GET_MODE (x);
 
 
  gcc_assert (GET_CODE (x) != CONST_INT
  gcc_assert (GET_CODE (x) != CONST_INT
              && (mode != VOIDmode || GET_CODE (x) != CONST_DOUBLE));
              && (mode != VOIDmode || GET_CODE (x) != CONST_DOUBLE));
 
 
  if (mode != GET_MODE (v->u.val_rtx))
  if (mode != GET_MODE (v->u.val_rtx))
    return 0;
    return 0;
 
 
  /* Unwrap X if necessary.  */
  /* Unwrap X if necessary.  */
  if (GET_CODE (x) == CONST
  if (GET_CODE (x) == CONST
      && (GET_CODE (XEXP (x, 0)) == CONST_INT
      && (GET_CODE (XEXP (x, 0)) == CONST_INT
          || GET_CODE (XEXP (x, 0)) == CONST_DOUBLE))
          || GET_CODE (XEXP (x, 0)) == CONST_DOUBLE))
    x = XEXP (x, 0);
    x = XEXP (x, 0);
 
 
  /* We don't guarantee that distinct rtx's have different hash values,
  /* We don't guarantee that distinct rtx's have different hash values,
     so we need to do a comparison.  */
     so we need to do a comparison.  */
  for (l = v->locs; l; l = l->next)
  for (l = v->locs; l; l = l->next)
    if (rtx_equal_for_cselib_p (l->loc, x))
    if (rtx_equal_for_cselib_p (l->loc, x))
      return 1;
      return 1;
 
 
  return 0;
  return 0;
}
}
 
 
/* The hash function for our hash table.  The value is always computed with
/* The hash function for our hash table.  The value is always computed with
   cselib_hash_rtx when adding an element; this function just extracts the
   cselib_hash_rtx when adding an element; this function just extracts the
   hash value from a cselib_val structure.  */
   hash value from a cselib_val structure.  */
 
 
static hashval_t
static hashval_t
get_value_hash (const void *entry)
get_value_hash (const void *entry)
{
{
  const cselib_val *v = (const cselib_val *) entry;
  const cselib_val *v = (const cselib_val *) entry;
  return v->value;
  return v->value;
}
}
 
 
/* Return true if X contains a VALUE rtx.  If ONLY_USELESS is set, we
/* Return true if X contains a VALUE rtx.  If ONLY_USELESS is set, we
   only return true for values which point to a cselib_val whose value
   only return true for values which point to a cselib_val whose value
   element has been set to zero, which implies the cselib_val will be
   element has been set to zero, which implies the cselib_val will be
   removed.  */
   removed.  */
 
 
int
int
references_value_p (rtx x, int only_useless)
references_value_p (rtx x, int only_useless)
{
{
  enum rtx_code code = GET_CODE (x);
  enum rtx_code code = GET_CODE (x);
  const char *fmt = GET_RTX_FORMAT (code);
  const char *fmt = GET_RTX_FORMAT (code);
  int i, j;
  int i, j;
 
 
  if (GET_CODE (x) == VALUE
  if (GET_CODE (x) == VALUE
      && (! only_useless || CSELIB_VAL_PTR (x)->locs == 0))
      && (! only_useless || CSELIB_VAL_PTR (x)->locs == 0))
    return 1;
    return 1;
 
 
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
    {
      if (fmt[i] == 'e' && references_value_p (XEXP (x, i), only_useless))
      if (fmt[i] == 'e' && references_value_p (XEXP (x, i), only_useless))
        return 1;
        return 1;
      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 (references_value_p (XVECEXP (x, i, j), only_useless))
          if (references_value_p (XVECEXP (x, i, j), only_useless))
            return 1;
            return 1;
    }
    }
 
 
  return 0;
  return 0;
}
}
 
 
/* For all locations found in X, delete locations that reference useless
/* For all locations found in X, delete locations that reference useless
   values (i.e. values without any location).  Called through
   values (i.e. values without any location).  Called through
   htab_traverse.  */
   htab_traverse.  */
 
 
static int
static int
discard_useless_locs (void **x, void *info ATTRIBUTE_UNUSED)
discard_useless_locs (void **x, void *info ATTRIBUTE_UNUSED)
{
{
  cselib_val *v = (cselib_val *)*x;
  cselib_val *v = (cselib_val *)*x;
  struct elt_loc_list **p = &v->locs;
  struct elt_loc_list **p = &v->locs;
  int had_locs = v->locs != 0;
  int had_locs = v->locs != 0;
 
 
  while (*p)
  while (*p)
    {
    {
      if (references_value_p ((*p)->loc, 1))
      if (references_value_p ((*p)->loc, 1))
        unchain_one_elt_loc_list (p);
        unchain_one_elt_loc_list (p);
      else
      else
        p = &(*p)->next;
        p = &(*p)->next;
    }
    }
 
 
  if (had_locs && v->locs == 0)
  if (had_locs && v->locs == 0)
    {
    {
      n_useless_values++;
      n_useless_values++;
      values_became_useless = 1;
      values_became_useless = 1;
    }
    }
  return 1;
  return 1;
}
}
 
 
/* If X is a value with no locations, remove it from the hashtable.  */
/* If X is a value with no locations, remove it from the hashtable.  */
 
 
static int
static int
discard_useless_values (void **x, void *info ATTRIBUTE_UNUSED)
discard_useless_values (void **x, void *info ATTRIBUTE_UNUSED)
{
{
  cselib_val *v = (cselib_val *)*x;
  cselib_val *v = (cselib_val *)*x;
 
 
  if (v->locs == 0)
  if (v->locs == 0)
    {
    {
      CSELIB_VAL_PTR (v->u.val_rtx) = NULL;
      CSELIB_VAL_PTR (v->u.val_rtx) = NULL;
      htab_clear_slot (cselib_hash_table, x);
      htab_clear_slot (cselib_hash_table, x);
      unchain_one_value (v);
      unchain_one_value (v);
      n_useless_values--;
      n_useless_values--;
    }
    }
 
 
  return 1;
  return 1;
}
}
 
 
/* Clean out useless values (i.e. those which no longer have locations
/* Clean out useless values (i.e. those which no longer have locations
   associated with them) from the hash table.  */
   associated with them) from the hash table.  */
 
 
static void
static void
remove_useless_values (void)
remove_useless_values (void)
{
{
  cselib_val **p, *v;
  cselib_val **p, *v;
  /* First pass: eliminate locations that reference the value.  That in
  /* First pass: eliminate locations that reference the value.  That in
     turn can make more values useless.  */
     turn can make more values useless.  */
  do
  do
    {
    {
      values_became_useless = 0;
      values_became_useless = 0;
      htab_traverse (cselib_hash_table, discard_useless_locs, 0);
      htab_traverse (cselib_hash_table, discard_useless_locs, 0);
    }
    }
  while (values_became_useless);
  while (values_became_useless);
 
 
  /* Second pass: actually remove the values.  */
  /* Second pass: actually remove the values.  */
 
 
  p = &first_containing_mem;
  p = &first_containing_mem;
  for (v = *p; v != &dummy_val; v = v->next_containing_mem)
  for (v = *p; v != &dummy_val; v = v->next_containing_mem)
    if (v->locs)
    if (v->locs)
      {
      {
        *p = v;
        *p = v;
        p = &(*p)->next_containing_mem;
        p = &(*p)->next_containing_mem;
      }
      }
  *p = &dummy_val;
  *p = &dummy_val;
 
 
  htab_traverse (cselib_hash_table, discard_useless_values, 0);
  htab_traverse (cselib_hash_table, discard_useless_values, 0);
 
 
  gcc_assert (!n_useless_values);
  gcc_assert (!n_useless_values);
}
}
 
 
/* Return the mode in which a register was last set.  If X is not a
/* Return the mode in which a register was last set.  If X is not a
   register, return its mode.  If the mode in which the register was
   register, return its mode.  If the mode in which the register was
   set is not known, or the value was already clobbered, return
   set is not known, or the value was already clobbered, return
   VOIDmode.  */
   VOIDmode.  */
 
 
enum machine_mode
enum machine_mode
cselib_reg_set_mode (rtx x)
cselib_reg_set_mode (rtx x)
{
{
  if (!REG_P (x))
  if (!REG_P (x))
    return GET_MODE (x);
    return GET_MODE (x);
 
 
  if (REG_VALUES (REGNO (x)) == NULL
  if (REG_VALUES (REGNO (x)) == NULL
      || REG_VALUES (REGNO (x))->elt == NULL)
      || REG_VALUES (REGNO (x))->elt == NULL)
    return VOIDmode;
    return VOIDmode;
 
 
  return GET_MODE (REG_VALUES (REGNO (x))->elt->u.val_rtx);
  return GET_MODE (REG_VALUES (REGNO (x))->elt->u.val_rtx);
}
}
 
 
/* Return nonzero if we can prove that X and Y contain the same value, taking
/* Return nonzero if we can prove that X and Y contain the same value, taking
   our gathered information into account.  */
   our gathered information into account.  */
 
 
int
int
rtx_equal_for_cselib_p (rtx x, rtx y)
rtx_equal_for_cselib_p (rtx x, rtx y)
{
{
  enum rtx_code code;
  enum rtx_code code;
  const char *fmt;
  const char *fmt;
  int i;
  int i;
 
 
  if (REG_P (x) || MEM_P (x))
  if (REG_P (x) || MEM_P (x))
    {
    {
      cselib_val *e = cselib_lookup (x, GET_MODE (x), 0);
      cselib_val *e = cselib_lookup (x, GET_MODE (x), 0);
 
 
      if (e)
      if (e)
        x = e->u.val_rtx;
        x = e->u.val_rtx;
    }
    }
 
 
  if (REG_P (y) || MEM_P (y))
  if (REG_P (y) || MEM_P (y))
    {
    {
      cselib_val *e = cselib_lookup (y, GET_MODE (y), 0);
      cselib_val *e = cselib_lookup (y, GET_MODE (y), 0);
 
 
      if (e)
      if (e)
        y = e->u.val_rtx;
        y = e->u.val_rtx;
    }
    }
 
 
  if (x == y)
  if (x == y)
    return 1;
    return 1;
 
 
  if (GET_CODE (x) == VALUE && GET_CODE (y) == VALUE)
  if (GET_CODE (x) == VALUE && GET_CODE (y) == VALUE)
    return CSELIB_VAL_PTR (x) == CSELIB_VAL_PTR (y);
    return CSELIB_VAL_PTR (x) == CSELIB_VAL_PTR (y);
 
 
  if (GET_CODE (x) == VALUE)
  if (GET_CODE (x) == VALUE)
    {
    {
      cselib_val *e = CSELIB_VAL_PTR (x);
      cselib_val *e = CSELIB_VAL_PTR (x);
      struct elt_loc_list *l;
      struct elt_loc_list *l;
 
 
      for (l = e->locs; l; l = l->next)
      for (l = e->locs; l; l = l->next)
        {
        {
          rtx t = l->loc;
          rtx t = l->loc;
 
 
          /* Avoid infinite recursion.  */
          /* Avoid infinite recursion.  */
          if (REG_P (t) || MEM_P (t))
          if (REG_P (t) || MEM_P (t))
            continue;
            continue;
          else if (rtx_equal_for_cselib_p (t, y))
          else if (rtx_equal_for_cselib_p (t, y))
            return 1;
            return 1;
        }
        }
 
 
      return 0;
      return 0;
    }
    }
 
 
  if (GET_CODE (y) == VALUE)
  if (GET_CODE (y) == VALUE)
    {
    {
      cselib_val *e = CSELIB_VAL_PTR (y);
      cselib_val *e = CSELIB_VAL_PTR (y);
      struct elt_loc_list *l;
      struct elt_loc_list *l;
 
 
      for (l = e->locs; l; l = l->next)
      for (l = e->locs; l; l = l->next)
        {
        {
          rtx t = l->loc;
          rtx t = l->loc;
 
 
          if (REG_P (t) || MEM_P (t))
          if (REG_P (t) || MEM_P (t))
            continue;
            continue;
          else if (rtx_equal_for_cselib_p (x, t))
          else if (rtx_equal_for_cselib_p (x, t))
            return 1;
            return 1;
        }
        }
 
 
      return 0;
      return 0;
    }
    }
 
 
  if (GET_CODE (x) != GET_CODE (y) || GET_MODE (x) != GET_MODE (y))
  if (GET_CODE (x) != GET_CODE (y) || GET_MODE (x) != GET_MODE (y))
    return 0;
    return 0;
 
 
  /* These won't be handled correctly by the code below.  */
  /* These won't be handled correctly by the code below.  */
  switch (GET_CODE (x))
  switch (GET_CODE (x))
    {
    {
    case CONST_DOUBLE:
    case CONST_DOUBLE:
      return 0;
      return 0;
 
 
    case LABEL_REF:
    case LABEL_REF:
      return XEXP (x, 0) == XEXP (y, 0);
      return XEXP (x, 0) == XEXP (y, 0);
 
 
    default:
    default:
      break;
      break;
    }
    }
 
 
  code = GET_CODE (x);
  code = GET_CODE (x);
  fmt = GET_RTX_FORMAT (code);
  fmt = GET_RTX_FORMAT (code);
 
 
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
    {
      int j;
      int j;
 
 
      switch (fmt[i])
      switch (fmt[i])
        {
        {
        case 'w':
        case 'w':
          if (XWINT (x, i) != XWINT (y, i))
          if (XWINT (x, i) != XWINT (y, i))
            return 0;
            return 0;
          break;
          break;
 
 
        case 'n':
        case 'n':
        case 'i':
        case 'i':
          if (XINT (x, i) != XINT (y, i))
          if (XINT (x, i) != XINT (y, i))
            return 0;
            return 0;
          break;
          break;
 
 
        case 'V':
        case 'V':
        case 'E':
        case 'E':
          /* Two vectors must have the same length.  */
          /* Two vectors must have the same length.  */
          if (XVECLEN (x, i) != XVECLEN (y, i))
          if (XVECLEN (x, i) != XVECLEN (y, i))
            return 0;
            return 0;
 
 
          /* And the corresponding elements must match.  */
          /* And the corresponding elements must match.  */
          for (j = 0; j < XVECLEN (x, i); j++)
          for (j = 0; j < XVECLEN (x, i); j++)
            if (! rtx_equal_for_cselib_p (XVECEXP (x, i, j),
            if (! rtx_equal_for_cselib_p (XVECEXP (x, i, j),
                                          XVECEXP (y, i, j)))
                                          XVECEXP (y, i, j)))
              return 0;
              return 0;
          break;
          break;
 
 
        case 'e':
        case 'e':
          if (i == 1
          if (i == 1
              && targetm.commutative_p (x, UNKNOWN)
              && targetm.commutative_p (x, UNKNOWN)
              && rtx_equal_for_cselib_p (XEXP (x, 1), XEXP (y, 0))
              && rtx_equal_for_cselib_p (XEXP (x, 1), XEXP (y, 0))
              && rtx_equal_for_cselib_p (XEXP (x, 0), XEXP (y, 1)))
              && rtx_equal_for_cselib_p (XEXP (x, 0), XEXP (y, 1)))
            return 1;
            return 1;
          if (! rtx_equal_for_cselib_p (XEXP (x, i), XEXP (y, i)))
          if (! rtx_equal_for_cselib_p (XEXP (x, i), XEXP (y, i)))
            return 0;
            return 0;
          break;
          break;
 
 
        case 'S':
        case 'S':
        case 's':
        case 's':
          if (strcmp (XSTR (x, i), XSTR (y, i)))
          if (strcmp (XSTR (x, i), XSTR (y, i)))
            return 0;
            return 0;
          break;
          break;
 
 
        case 'u':
        case 'u':
          /* These are just backpointers, so they don't matter.  */
          /* These are just backpointers, so they don't matter.  */
          break;
          break;
 
 
        case '0':
        case '0':
        case 't':
        case 't':
          break;
          break;
 
 
          /* It is believed that rtx's at this level will never
          /* It is believed that rtx's at this level will never
             contain anything but integers and other rtx's,
             contain anything but integers and other rtx's,
             except for within LABEL_REFs and SYMBOL_REFs.  */
             except for within LABEL_REFs and SYMBOL_REFs.  */
        default:
        default:
          gcc_unreachable ();
          gcc_unreachable ();
        }
        }
    }
    }
  return 1;
  return 1;
}
}
 
 
/* We need to pass down the mode of constants through the hash table
/* We need to pass down the mode of constants through the hash table
   functions.  For that purpose, wrap them in a CONST of the appropriate
   functions.  For that purpose, wrap them in a CONST of the appropriate
   mode.  */
   mode.  */
static rtx
static rtx
wrap_constant (enum machine_mode mode, rtx x)
wrap_constant (enum machine_mode mode, rtx x)
{
{
  if (GET_CODE (x) != CONST_INT
  if (GET_CODE (x) != CONST_INT
      && (GET_CODE (x) != CONST_DOUBLE || GET_MODE (x) != VOIDmode))
      && (GET_CODE (x) != CONST_DOUBLE || GET_MODE (x) != VOIDmode))
    return x;
    return x;
  gcc_assert (mode != VOIDmode);
  gcc_assert (mode != VOIDmode);
  return gen_rtx_CONST (mode, x);
  return gen_rtx_CONST (mode, x);
}
}
 
 
/* Hash an rtx.  Return 0 if we couldn't hash the rtx.
/* Hash an rtx.  Return 0 if we couldn't hash the rtx.
   For registers and memory locations, we look up their cselib_val structure
   For registers and memory locations, we look up their cselib_val structure
   and return its VALUE element.
   and return its VALUE element.
   Possible reasons for return 0 are: the object is volatile, or we couldn't
   Possible reasons for return 0 are: the object is volatile, or we couldn't
   find a register or memory location in the table and CREATE is zero.  If
   find a register or memory location in the table and CREATE is zero.  If
   CREATE is nonzero, table elts are created for regs and mem.
   CREATE is nonzero, table elts are created for regs and mem.
   N.B. this hash function returns the same hash value for RTXes that
   N.B. this hash function returns the same hash value for RTXes that
   differ only in the order of operands, thus it is suitable for comparisons
   differ only in the order of operands, thus it is suitable for comparisons
   that take commutativity into account.
   that take commutativity into account.
   If we wanted to also support associative rules, we'd have to use a different
   If we wanted to also support associative rules, we'd have to use a different
   strategy to avoid returning spurious 0, e.g. return ~(~0U >> 1) .
   strategy to avoid returning spurious 0, e.g. return ~(~0U >> 1) .
   We used to have a MODE argument for hashing for CONST_INTs, but that
   We used to have a MODE argument for hashing for CONST_INTs, but that
   didn't make sense, since it caused spurious hash differences between
   didn't make sense, since it caused spurious hash differences between
    (set (reg:SI 1) (const_int))
    (set (reg:SI 1) (const_int))
    (plus:SI (reg:SI 2) (reg:SI 1))
    (plus:SI (reg:SI 2) (reg:SI 1))
   and
   and
    (plus:SI (reg:SI 2) (const_int))
    (plus:SI (reg:SI 2) (const_int))
   If the mode is important in any context, it must be checked specifically
   If the mode is important in any context, it must be checked specifically
   in a comparison anyway, since relying on hash differences is unsafe.  */
   in a comparison anyway, since relying on hash differences is unsafe.  */
 
 
static unsigned int
static unsigned int
cselib_hash_rtx (rtx x, int create)
cselib_hash_rtx (rtx x, int create)
{
{
  cselib_val *e;
  cselib_val *e;
  int i, j;
  int i, j;
  enum rtx_code code;
  enum rtx_code code;
  const char *fmt;
  const char *fmt;
  unsigned int hash = 0;
  unsigned int hash = 0;
 
 
  code = GET_CODE (x);
  code = GET_CODE (x);
  hash += (unsigned) code + (unsigned) GET_MODE (x);
  hash += (unsigned) code + (unsigned) GET_MODE (x);
 
 
  switch (code)
  switch (code)
    {
    {
    case MEM:
    case MEM:
    case REG:
    case REG:
      e = cselib_lookup (x, GET_MODE (x), create);
      e = cselib_lookup (x, GET_MODE (x), create);
      if (! e)
      if (! e)
        return 0;
        return 0;
 
 
      return e->value;
      return e->value;
 
 
    case CONST_INT:
    case CONST_INT:
      hash += ((unsigned) CONST_INT << 7) + INTVAL (x);
      hash += ((unsigned) CONST_INT << 7) + INTVAL (x);
      return hash ? hash : (unsigned int) CONST_INT;
      return hash ? hash : (unsigned int) CONST_INT;
 
 
    case CONST_DOUBLE:
    case CONST_DOUBLE:
      /* This is like the general case, except that it only counts
      /* This is like the general case, except that it only counts
         the integers representing the constant.  */
         the integers representing the constant.  */
      hash += (unsigned) code + (unsigned) GET_MODE (x);
      hash += (unsigned) code + (unsigned) GET_MODE (x);
      if (GET_MODE (x) != VOIDmode)
      if (GET_MODE (x) != VOIDmode)
        hash += real_hash (CONST_DOUBLE_REAL_VALUE (x));
        hash += real_hash (CONST_DOUBLE_REAL_VALUE (x));
      else
      else
        hash += ((unsigned) CONST_DOUBLE_LOW (x)
        hash += ((unsigned) CONST_DOUBLE_LOW (x)
                 + (unsigned) CONST_DOUBLE_HIGH (x));
                 + (unsigned) CONST_DOUBLE_HIGH (x));
      return hash ? hash : (unsigned int) CONST_DOUBLE;
      return hash ? hash : (unsigned int) CONST_DOUBLE;
 
 
    case CONST_VECTOR:
    case CONST_VECTOR:
      {
      {
        int units;
        int units;
        rtx elt;
        rtx elt;
 
 
        units = CONST_VECTOR_NUNITS (x);
        units = CONST_VECTOR_NUNITS (x);
 
 
        for (i = 0; i < units; ++i)
        for (i = 0; i < units; ++i)
          {
          {
            elt = CONST_VECTOR_ELT (x, i);
            elt = CONST_VECTOR_ELT (x, i);
            hash += cselib_hash_rtx (elt, 0);
            hash += cselib_hash_rtx (elt, 0);
          }
          }
 
 
        return hash;
        return hash;
      }
      }
 
 
      /* Assume there is only one rtx object for any given label.  */
      /* Assume there is only one rtx object for any given label.  */
    case LABEL_REF:
    case LABEL_REF:
      /* We don't hash on the address of the CODE_LABEL to avoid bootstrap
      /* We don't hash on the address of the CODE_LABEL to avoid bootstrap
         differences and differences between each stage's debugging dumps.  */
         differences and differences between each stage's debugging dumps.  */
      hash += (((unsigned int) LABEL_REF << 7)
      hash += (((unsigned int) LABEL_REF << 7)
               + CODE_LABEL_NUMBER (XEXP (x, 0)));
               + CODE_LABEL_NUMBER (XEXP (x, 0)));
      return hash ? hash : (unsigned int) LABEL_REF;
      return hash ? hash : (unsigned int) LABEL_REF;
 
 
    case SYMBOL_REF:
    case SYMBOL_REF:
      {
      {
        /* Don't hash on the symbol's address to avoid bootstrap differences.
        /* Don't hash on the symbol's address to avoid bootstrap differences.
           Different hash values may cause expressions to be recorded in
           Different hash values may cause expressions to be recorded in
           different orders and thus different registers to be used in the
           different orders and thus different registers to be used in the
           final assembler.  This also avoids differences in the dump files
           final assembler.  This also avoids differences in the dump files
           between various stages.  */
           between various stages.  */
        unsigned int h = 0;
        unsigned int h = 0;
        const unsigned char *p = (const unsigned char *) XSTR (x, 0);
        const unsigned char *p = (const unsigned char *) XSTR (x, 0);
 
 
        while (*p)
        while (*p)
          h += (h << 7) + *p++; /* ??? revisit */
          h += (h << 7) + *p++; /* ??? revisit */
 
 
        hash += ((unsigned int) SYMBOL_REF << 7) + h;
        hash += ((unsigned int) SYMBOL_REF << 7) + h;
        return hash ? hash : (unsigned int) SYMBOL_REF;
        return hash ? hash : (unsigned int) SYMBOL_REF;
      }
      }
 
 
    case PRE_DEC:
    case PRE_DEC:
    case PRE_INC:
    case PRE_INC:
    case POST_DEC:
    case POST_DEC:
    case POST_INC:
    case POST_INC:
    case POST_MODIFY:
    case POST_MODIFY:
    case PRE_MODIFY:
    case PRE_MODIFY:
    case PC:
    case PC:
    case CC0:
    case CC0:
    case CALL:
    case CALL:
    case UNSPEC_VOLATILE:
    case UNSPEC_VOLATILE:
      return 0;
      return 0;
 
 
    case ASM_OPERANDS:
    case ASM_OPERANDS:
      if (MEM_VOLATILE_P (x))
      if (MEM_VOLATILE_P (x))
        return 0;
        return 0;
 
 
      break;
      break;
 
 
    default:
    default:
      break;
      break;
    }
    }
 
 
  i = GET_RTX_LENGTH (code) - 1;
  i = GET_RTX_LENGTH (code) - 1;
  fmt = GET_RTX_FORMAT (code);
  fmt = GET_RTX_FORMAT (code);
  for (; i >= 0; i--)
  for (; i >= 0; i--)
    {
    {
      switch (fmt[i])
      switch (fmt[i])
        {
        {
        case 'e':
        case 'e':
          {
          {
            rtx tem = XEXP (x, i);
            rtx tem = XEXP (x, i);
            unsigned int tem_hash = cselib_hash_rtx (tem, create);
            unsigned int tem_hash = cselib_hash_rtx (tem, create);
 
 
            if (tem_hash == 0)
            if (tem_hash == 0)
              return 0;
              return 0;
 
 
            hash += tem_hash;
            hash += tem_hash;
          }
          }
          break;
          break;
        case 'E':
        case 'E':
          for (j = 0; j < XVECLEN (x, i); j++)
          for (j = 0; j < XVECLEN (x, i); j++)
            {
            {
              unsigned int tem_hash
              unsigned int tem_hash
                = cselib_hash_rtx (XVECEXP (x, i, j), create);
                = cselib_hash_rtx (XVECEXP (x, i, j), create);
 
 
              if (tem_hash == 0)
              if (tem_hash == 0)
                return 0;
                return 0;
 
 
              hash += tem_hash;
              hash += tem_hash;
            }
            }
          break;
          break;
 
 
        case 's':
        case 's':
          {
          {
            const unsigned char *p = (const unsigned char *) XSTR (x, i);
            const unsigned char *p = (const unsigned char *) XSTR (x, i);
 
 
            if (p)
            if (p)
              while (*p)
              while (*p)
                hash += *p++;
                hash += *p++;
            break;
            break;
          }
          }
 
 
        case 'i':
        case 'i':
          hash += XINT (x, i);
          hash += XINT (x, i);
          break;
          break;
 
 
        case '0':
        case '0':
        case 't':
        case 't':
          /* unused */
          /* unused */
          break;
          break;
 
 
        default:
        default:
          gcc_unreachable ();
          gcc_unreachable ();
        }
        }
    }
    }
 
 
  return hash ? hash : 1 + (unsigned int) GET_CODE (x);
  return hash ? hash : 1 + (unsigned int) GET_CODE (x);
}
}
 
 
/* Create a new value structure for VALUE and initialize it.  The mode of the
/* Create a new value structure for VALUE and initialize it.  The mode of the
   value is MODE.  */
   value is MODE.  */
 
 
static inline cselib_val *
static inline cselib_val *
new_cselib_val (unsigned int value, enum machine_mode mode)
new_cselib_val (unsigned int value, enum machine_mode mode)
{
{
  cselib_val *e = pool_alloc (cselib_val_pool);
  cselib_val *e = pool_alloc (cselib_val_pool);
 
 
  gcc_assert (value);
  gcc_assert (value);
 
 
  e->value = value;
  e->value = value;
  /* We use an alloc pool to allocate this RTL construct because it
  /* We use an alloc pool to allocate this RTL construct because it
     accounts for about 8% of the overall memory usage.  We know
     accounts for about 8% of the overall memory usage.  We know
     precisely when we can have VALUE RTXen (when cselib is active)
     precisely when we can have VALUE RTXen (when cselib is active)
     so we don't need to put them in garbage collected memory.
     so we don't need to put them in garbage collected memory.
     ??? Why should a VALUE be an RTX in the first place?  */
     ??? Why should a VALUE be an RTX in the first place?  */
  e->u.val_rtx = pool_alloc (value_pool);
  e->u.val_rtx = pool_alloc (value_pool);
  memset (e->u.val_rtx, 0, RTX_HDR_SIZE);
  memset (e->u.val_rtx, 0, RTX_HDR_SIZE);
  PUT_CODE (e->u.val_rtx, VALUE);
  PUT_CODE (e->u.val_rtx, VALUE);
  PUT_MODE (e->u.val_rtx, mode);
  PUT_MODE (e->u.val_rtx, mode);
  CSELIB_VAL_PTR (e->u.val_rtx) = e;
  CSELIB_VAL_PTR (e->u.val_rtx) = e;
  e->addr_list = 0;
  e->addr_list = 0;
  e->locs = 0;
  e->locs = 0;
  e->next_containing_mem = 0;
  e->next_containing_mem = 0;
  return e;
  return e;
}
}
 
 
/* ADDR_ELT is a value that is used as address.  MEM_ELT is the value that
/* ADDR_ELT is a value that is used as address.  MEM_ELT is the value that
   contains the data at this address.  X is a MEM that represents the
   contains the data at this address.  X is a MEM that represents the
   value.  Update the two value structures to represent this situation.  */
   value.  Update the two value structures to represent this situation.  */
 
 
static void
static void
add_mem_for_addr (cselib_val *addr_elt, cselib_val *mem_elt, rtx x)
add_mem_for_addr (cselib_val *addr_elt, cselib_val *mem_elt, rtx x)
{
{
  struct elt_loc_list *l;
  struct elt_loc_list *l;
 
 
  /* Avoid duplicates.  */
  /* Avoid duplicates.  */
  for (l = mem_elt->locs; l; l = l->next)
  for (l = mem_elt->locs; l; l = l->next)
    if (MEM_P (l->loc)
    if (MEM_P (l->loc)
        && CSELIB_VAL_PTR (XEXP (l->loc, 0)) == addr_elt)
        && CSELIB_VAL_PTR (XEXP (l->loc, 0)) == addr_elt)
      return;
      return;
 
 
  addr_elt->addr_list = new_elt_list (addr_elt->addr_list, mem_elt);
  addr_elt->addr_list = new_elt_list (addr_elt->addr_list, mem_elt);
  mem_elt->locs
  mem_elt->locs
    = new_elt_loc_list (mem_elt->locs,
    = new_elt_loc_list (mem_elt->locs,
                        replace_equiv_address_nv (x, addr_elt->u.val_rtx));
                        replace_equiv_address_nv (x, addr_elt->u.val_rtx));
  if (mem_elt->next_containing_mem == NULL)
  if (mem_elt->next_containing_mem == NULL)
    {
    {
      mem_elt->next_containing_mem = first_containing_mem;
      mem_elt->next_containing_mem = first_containing_mem;
      first_containing_mem = mem_elt;
      first_containing_mem = mem_elt;
    }
    }
}
}
 
 
/* Subroutine of cselib_lookup.  Return a value for X, which is a MEM rtx.
/* Subroutine of cselib_lookup.  Return a value for X, which is a MEM rtx.
   If CREATE, make a new one if we haven't seen it before.  */
   If CREATE, make a new one if we haven't seen it before.  */
 
 
static cselib_val *
static cselib_val *
cselib_lookup_mem (rtx x, int create)
cselib_lookup_mem (rtx x, int create)
{
{
  enum machine_mode mode = GET_MODE (x);
  enum machine_mode mode = GET_MODE (x);
  void **slot;
  void **slot;
  cselib_val *addr;
  cselib_val *addr;
  cselib_val *mem_elt;
  cselib_val *mem_elt;
  struct elt_list *l;
  struct elt_list *l;
 
 
  if (MEM_VOLATILE_P (x) || mode == BLKmode
  if (MEM_VOLATILE_P (x) || mode == BLKmode
      || !cselib_record_memory
      || !cselib_record_memory
      || (FLOAT_MODE_P (mode) && flag_float_store))
      || (FLOAT_MODE_P (mode) && flag_float_store))
    return 0;
    return 0;
 
 
  /* Look up the value for the address.  */
  /* Look up the value for the address.  */
  addr = cselib_lookup (XEXP (x, 0), mode, create);
  addr = cselib_lookup (XEXP (x, 0), mode, create);
  if (! addr)
  if (! addr)
    return 0;
    return 0;
 
 
  /* Find a value that describes a value of our mode at that address.  */
  /* Find a value that describes a value of our mode at that address.  */
  for (l = addr->addr_list; l; l = l->next)
  for (l = addr->addr_list; l; l = l->next)
    if (GET_MODE (l->elt->u.val_rtx) == mode)
    if (GET_MODE (l->elt->u.val_rtx) == mode)
      return l->elt;
      return l->elt;
 
 
  if (! create)
  if (! create)
    return 0;
    return 0;
 
 
  mem_elt = new_cselib_val (++next_unknown_value, mode);
  mem_elt = new_cselib_val (++next_unknown_value, mode);
  add_mem_for_addr (addr, mem_elt, x);
  add_mem_for_addr (addr, mem_elt, x);
  slot = htab_find_slot_with_hash (cselib_hash_table, wrap_constant (mode, x),
  slot = htab_find_slot_with_hash (cselib_hash_table, wrap_constant (mode, x),
                                   mem_elt->value, INSERT);
                                   mem_elt->value, INSERT);
  *slot = mem_elt;
  *slot = mem_elt;
  return mem_elt;
  return mem_elt;
}
}
 
 
/* Walk rtx X and replace all occurrences of REG and MEM subexpressions
/* Walk rtx X and replace all occurrences of REG and MEM subexpressions
   with VALUE expressions.  This way, it becomes independent of changes
   with VALUE expressions.  This way, it becomes independent of changes
   to registers and memory.
   to registers and memory.
   X isn't actually modified; if modifications are needed, new rtl is
   X isn't actually modified; if modifications are needed, new rtl is
   allocated.  However, the return value can share rtl with X.  */
   allocated.  However, the return value can share rtl with X.  */
 
 
rtx
rtx
cselib_subst_to_values (rtx x)
cselib_subst_to_values (rtx x)
{
{
  enum rtx_code code = GET_CODE (x);
  enum rtx_code code = GET_CODE (x);
  const char *fmt = GET_RTX_FORMAT (code);
  const char *fmt = GET_RTX_FORMAT (code);
  cselib_val *e;
  cselib_val *e;
  struct elt_list *l;
  struct elt_list *l;
  rtx copy = x;
  rtx copy = x;
  int i;
  int i;
 
 
  switch (code)
  switch (code)
    {
    {
    case REG:
    case REG:
      l = REG_VALUES (REGNO (x));
      l = REG_VALUES (REGNO (x));
      if (l && l->elt == NULL)
      if (l && l->elt == NULL)
        l = l->next;
        l = l->next;
      for (; l; l = l->next)
      for (; l; l = l->next)
        if (GET_MODE (l->elt->u.val_rtx) == GET_MODE (x))
        if (GET_MODE (l->elt->u.val_rtx) == GET_MODE (x))
          return l->elt->u.val_rtx;
          return l->elt->u.val_rtx;
 
 
      gcc_unreachable ();
      gcc_unreachable ();
 
 
    case MEM:
    case MEM:
      e = cselib_lookup_mem (x, 0);
      e = cselib_lookup_mem (x, 0);
      if (! e)
      if (! e)
        {
        {
          /* This happens for autoincrements.  Assign a value that doesn't
          /* This happens for autoincrements.  Assign a value that doesn't
             match any other.  */
             match any other.  */
          e = new_cselib_val (++next_unknown_value, GET_MODE (x));
          e = new_cselib_val (++next_unknown_value, GET_MODE (x));
        }
        }
      return e->u.val_rtx;
      return e->u.val_rtx;
 
 
    case CONST_DOUBLE:
    case CONST_DOUBLE:
    case CONST_VECTOR:
    case CONST_VECTOR:
    case CONST_INT:
    case CONST_INT:
      return x;
      return x;
 
 
    case POST_INC:
    case POST_INC:
    case PRE_INC:
    case PRE_INC:
    case POST_DEC:
    case POST_DEC:
    case PRE_DEC:
    case PRE_DEC:
    case POST_MODIFY:
    case POST_MODIFY:
    case PRE_MODIFY:
    case PRE_MODIFY:
      e = new_cselib_val (++next_unknown_value, GET_MODE (x));
      e = new_cselib_val (++next_unknown_value, GET_MODE (x));
      return e->u.val_rtx;
      return e->u.val_rtx;
 
 
    default:
    default:
      break;
      break;
    }
    }
 
 
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
  for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
    {
    {
      if (fmt[i] == 'e')
      if (fmt[i] == 'e')
        {
        {
          rtx t = cselib_subst_to_values (XEXP (x, i));
          rtx t = cselib_subst_to_values (XEXP (x, i));
 
 
          if (t != XEXP (x, i) && x == copy)
          if (t != XEXP (x, i) && x == copy)
            copy = shallow_copy_rtx (x);
            copy = shallow_copy_rtx (x);
 
 
          XEXP (copy, i) = t;
          XEXP (copy, i) = t;
        }
        }
      else if (fmt[i] == 'E')
      else if (fmt[i] == 'E')
        {
        {
          int j, k;
          int j, k;
 
 
          for (j = 0; j < XVECLEN (x, i); j++)
          for (j = 0; j < XVECLEN (x, i); j++)
            {
            {
              rtx t = cselib_subst_to_values (XVECEXP (x, i, j));
              rtx t = cselib_subst_to_values (XVECEXP (x, i, j));
 
 
              if (t != XVECEXP (x, i, j) && XVEC (x, i) == XVEC (copy, i))
              if (t != XVECEXP (x, i, j) && XVEC (x, i) == XVEC (copy, i))
                {
                {
                  if (x == copy)
                  if (x == copy)
                    copy = shallow_copy_rtx (x);
                    copy = shallow_copy_rtx (x);
 
 
                  XVEC (copy, i) = rtvec_alloc (XVECLEN (x, i));
                  XVEC (copy, i) = rtvec_alloc (XVECLEN (x, i));
                  for (k = 0; k < j; k++)
                  for (k = 0; k < j; k++)
                    XVECEXP (copy, i, k) = XVECEXP (x, i, k);
                    XVECEXP (copy, i, k) = XVECEXP (x, i, k);
                }
                }
 
 
              XVECEXP (copy, i, j) = t;
              XVECEXP (copy, i, j) = t;
            }
            }
        }
        }
    }
    }
 
 
  return copy;
  return copy;
}
}
 
 
/* Look up the rtl expression X in our tables and return the value it has.
/* Look up the rtl expression X in our tables and return the value it has.
   If CREATE is zero, we return NULL if we don't know the value.  Otherwise,
   If CREATE is zero, we return NULL if we don't know the value.  Otherwise,
   we create a new one if possible, using mode MODE if X doesn't have a mode
   we create a new one if possible, using mode MODE if X doesn't have a mode
   (i.e. because it's a constant).  */
   (i.e. because it's a constant).  */
 
 
cselib_val *
cselib_val *
cselib_lookup (rtx x, enum machine_mode mode, int create)
cselib_lookup (rtx x, enum machine_mode mode, int create)
{
{
  void **slot;
  void **slot;
  cselib_val *e;
  cselib_val *e;
  unsigned int hashval;
  unsigned int hashval;
 
 
  if (GET_MODE (x) != VOIDmode)
  if (GET_MODE (x) != VOIDmode)
    mode = GET_MODE (x);
    mode = GET_MODE (x);
 
 
  if (GET_CODE (x) == VALUE)
  if (GET_CODE (x) == VALUE)
    return CSELIB_VAL_PTR (x);
    return CSELIB_VAL_PTR (x);
 
 
  if (REG_P (x))
  if (REG_P (x))
    {
    {
      struct elt_list *l;
      struct elt_list *l;
      unsigned int i = REGNO (x);
      unsigned int i = REGNO (x);
 
 
      l = REG_VALUES (i);
      l = REG_VALUES (i);
      if (l && l->elt == NULL)
      if (l && l->elt == NULL)
        l = l->next;
        l = l->next;
      for (; l; l = l->next)
      for (; l; l = l->next)
        if (mode == GET_MODE (l->elt->u.val_rtx))
        if (mode == GET_MODE (l->elt->u.val_rtx))
          return l->elt;
          return l->elt;
 
 
      if (! create)
      if (! create)
        return 0;
        return 0;
 
 
      if (i < FIRST_PSEUDO_REGISTER)
      if (i < FIRST_PSEUDO_REGISTER)
        {
        {
          unsigned int n = hard_regno_nregs[i][mode];
          unsigned int n = hard_regno_nregs[i][mode];
 
 
          if (n > max_value_regs)
          if (n > max_value_regs)
            max_value_regs = n;
            max_value_regs = n;
        }
        }
 
 
      e = new_cselib_val (++next_unknown_value, GET_MODE (x));
      e = new_cselib_val (++next_unknown_value, GET_MODE (x));
      e->locs = new_elt_loc_list (e->locs, x);
      e->locs = new_elt_loc_list (e->locs, x);
      if (REG_VALUES (i) == 0)
      if (REG_VALUES (i) == 0)
        {
        {
          /* Maintain the invariant that the first entry of
          /* Maintain the invariant that the first entry of
             REG_VALUES, if present, must be the value used to set the
             REG_VALUES, if present, must be the value used to set the
             register, or NULL.  */
             register, or NULL.  */
          used_regs[n_used_regs++] = i;
          used_regs[n_used_regs++] = i;
          REG_VALUES (i) = new_elt_list (REG_VALUES (i), NULL);
          REG_VALUES (i) = new_elt_list (REG_VALUES (i), NULL);
        }
        }
      REG_VALUES (i)->next = new_elt_list (REG_VALUES (i)->next, e);
      REG_VALUES (i)->next = new_elt_list (REG_VALUES (i)->next, e);
      slot = htab_find_slot_with_hash (cselib_hash_table, x, e->value, INSERT);
      slot = htab_find_slot_with_hash (cselib_hash_table, x, e->value, INSERT);
      *slot = e;
      *slot = e;
      return e;
      return e;
    }
    }
 
 
  if (MEM_P (x))
  if (MEM_P (x))
    return cselib_lookup_mem (x, create);
    return cselib_lookup_mem (x, create);
 
 
  hashval = cselib_hash_rtx (x, create);
  hashval = cselib_hash_rtx (x, create);
  /* Can't even create if hashing is not possible.  */
  /* Can't even create if hashing is not possible.  */
  if (! hashval)
  if (! hashval)
    return 0;
    return 0;
 
 
  slot = htab_find_slot_with_hash (cselib_hash_table, wrap_constant (mode, x),
  slot = htab_find_slot_with_hash (cselib_hash_table, wrap_constant (mode, x),
                                   hashval, create ? INSERT : NO_INSERT);
                                   hashval, create ? INSERT : NO_INSERT);
  if (slot == 0)
  if (slot == 0)
    return 0;
    return 0;
 
 
  e = (cselib_val *) *slot;
  e = (cselib_val *) *slot;
  if (e)
  if (e)
    return e;
    return e;
 
 
  e = new_cselib_val (hashval, mode);
  e = new_cselib_val (hashval, mode);
 
 
  /* We have to fill the slot before calling cselib_subst_to_values:
  /* We have to fill the slot before calling cselib_subst_to_values:
     the hash table is inconsistent until we do so, and
     the hash table is inconsistent until we do so, and
     cselib_subst_to_values will need to do lookups.  */
     cselib_subst_to_values will need to do lookups.  */
  *slot = (void *) e;
  *slot = (void *) e;
  e->locs = new_elt_loc_list (e->locs, cselib_subst_to_values (x));
  e->locs = new_elt_loc_list (e->locs, cselib_subst_to_values (x));
  return e;
  return e;
}
}
 
 
/* Invalidate any entries in reg_values that overlap REGNO.  This is called
/* Invalidate any entries in reg_values that overlap REGNO.  This is called
   if REGNO is changing.  MODE is the mode of the assignment to REGNO, which
   if REGNO is changing.  MODE is the mode of the assignment to REGNO, which
   is used to determine how many hard registers are being changed.  If MODE
   is used to determine how many hard registers are being changed.  If MODE
   is VOIDmode, then only REGNO is being changed; this is used when
   is VOIDmode, then only REGNO is being changed; this is used when
   invalidating call clobbered registers across a call.  */
   invalidating call clobbered registers across a call.  */
 
 
static void
static void
cselib_invalidate_regno (unsigned int regno, enum machine_mode mode)
cselib_invalidate_regno (unsigned int regno, enum machine_mode mode)
{
{
  unsigned int endregno;
  unsigned int endregno;
  unsigned int i;
  unsigned int i;
 
 
  /* If we see pseudos after reload, something is _wrong_.  */
  /* If we see pseudos after reload, something is _wrong_.  */
  gcc_assert (!reload_completed || regno < FIRST_PSEUDO_REGISTER
  gcc_assert (!reload_completed || regno < FIRST_PSEUDO_REGISTER
              || reg_renumber[regno] < 0);
              || reg_renumber[regno] < 0);
 
 
  /* Determine the range of registers that must be invalidated.  For
  /* Determine the range of registers that must be invalidated.  For
     pseudos, only REGNO is affected.  For hard regs, we must take MODE
     pseudos, only REGNO is affected.  For hard regs, we must take MODE
     into account, and we must also invalidate lower register numbers
     into account, and we must also invalidate lower register numbers
     if they contain values that overlap REGNO.  */
     if they contain values that overlap REGNO.  */
  if (regno < FIRST_PSEUDO_REGISTER)
  if (regno < FIRST_PSEUDO_REGISTER)
    {
    {
      gcc_assert (mode != VOIDmode);
      gcc_assert (mode != VOIDmode);
 
 
      if (regno < max_value_regs)
      if (regno < max_value_regs)
        i = 0;
        i = 0;
      else
      else
        i = regno - max_value_regs;
        i = regno - max_value_regs;
 
 
      endregno = regno + hard_regno_nregs[regno][mode];
      endregno = regno + hard_regno_nregs[regno][mode];
    }
    }
  else
  else
    {
    {
      i = regno;
      i = regno;
      endregno = regno + 1;
      endregno = regno + 1;
    }
    }
 
 
  for (; i < endregno; i++)
  for (; i < endregno; i++)
    {
    {
      struct elt_list **l = &REG_VALUES (i);
      struct elt_list **l = &REG_VALUES (i);
 
 
      /* Go through all known values for this reg; if it overlaps the range
      /* Go through all known values for this reg; if it overlaps the range
         we're invalidating, remove the value.  */
         we're invalidating, remove the value.  */
      while (*l)
      while (*l)
        {
        {
          cselib_val *v = (*l)->elt;
          cselib_val *v = (*l)->elt;
          struct elt_loc_list **p;
          struct elt_loc_list **p;
          unsigned int this_last = i;
          unsigned int this_last = i;
 
 
          if (i < FIRST_PSEUDO_REGISTER && v != NULL)
          if (i < FIRST_PSEUDO_REGISTER && v != NULL)
            this_last += hard_regno_nregs[i][GET_MODE (v->u.val_rtx)] - 1;
            this_last += hard_regno_nregs[i][GET_MODE (v->u.val_rtx)] - 1;
 
 
          if (this_last < regno || v == NULL)
          if (this_last < regno || v == NULL)
            {
            {
              l = &(*l)->next;
              l = &(*l)->next;
              continue;
              continue;
            }
            }
 
 
          /* We have an overlap.  */
          /* We have an overlap.  */
          if (*l == REG_VALUES (i))
          if (*l == REG_VALUES (i))
            {
            {
              /* Maintain the invariant that the first entry of
              /* Maintain the invariant that the first entry of
                 REG_VALUES, if present, must be the value used to set
                 REG_VALUES, if present, must be the value used to set
                 the register, or NULL.  This is also nice because
                 the register, or NULL.  This is also nice because
                 then we won't push the same regno onto user_regs
                 then we won't push the same regno onto user_regs
                 multiple times.  */
                 multiple times.  */
              (*l)->elt = NULL;
              (*l)->elt = NULL;
              l = &(*l)->next;
              l = &(*l)->next;
            }
            }
          else
          else
            unchain_one_elt_list (l);
            unchain_one_elt_list (l);
 
 
          /* Now, we clear the mapping from value to reg.  It must exist, so
          /* Now, we clear the mapping from value to reg.  It must exist, so
             this code will crash intentionally if it doesn't.  */
             this code will crash intentionally if it doesn't.  */
          for (p = &v->locs; ; p = &(*p)->next)
          for (p = &v->locs; ; p = &(*p)->next)
            {
            {
              rtx x = (*p)->loc;
              rtx x = (*p)->loc;
 
 
              if (REG_P (x) && REGNO (x) == i)
              if (REG_P (x) && REGNO (x) == i)
                {
                {
                  unchain_one_elt_loc_list (p);
                  unchain_one_elt_loc_list (p);
                  break;
                  break;
                }
                }
            }
            }
          if (v->locs == 0)
          if (v->locs == 0)
            n_useless_values++;
            n_useless_values++;
        }
        }
    }
    }
}
}


/* Return 1 if X has a value that can vary even between two
/* Return 1 if X has a value that can vary even between two
   executions of the program.  0 means X can be compared reliably
   executions of the program.  0 means X can be compared reliably
   against certain constants or near-constants.  */
   against certain constants or near-constants.  */
 
 
static int
static int
cselib_rtx_varies_p (rtx x ATTRIBUTE_UNUSED, int from_alias ATTRIBUTE_UNUSED)
cselib_rtx_varies_p (rtx x ATTRIBUTE_UNUSED, int from_alias ATTRIBUTE_UNUSED)
{
{
  /* We actually don't need to verify very hard.  This is because
  /* We actually don't need to verify very hard.  This is because
     if X has actually changed, we invalidate the memory anyway,
     if X has actually changed, we invalidate the memory anyway,
     so assume that all common memory addresses are
     so assume that all common memory addresses are
     invariant.  */
     invariant.  */
  return 0;
  return 0;
}
}
 
 
/* Invalidate any locations in the table which are changed because of a
/* Invalidate any locations in the table which are changed because of a
   store to MEM_RTX.  If this is called because of a non-const call
   store to MEM_RTX.  If this is called because of a non-const call
   instruction, MEM_RTX is (mem:BLK const0_rtx).  */
   instruction, MEM_RTX is (mem:BLK const0_rtx).  */
 
 
static void
static void
cselib_invalidate_mem (rtx mem_rtx)
cselib_invalidate_mem (rtx mem_rtx)
{
{
  cselib_val **vp, *v, *next;
  cselib_val **vp, *v, *next;
  int num_mems = 0;
  int num_mems = 0;
  rtx mem_addr;
  rtx mem_addr;
 
 
  mem_addr = canon_rtx (get_addr (XEXP (mem_rtx, 0)));
  mem_addr = canon_rtx (get_addr (XEXP (mem_rtx, 0)));
  mem_rtx = canon_rtx (mem_rtx);
  mem_rtx = canon_rtx (mem_rtx);
 
 
  vp = &first_containing_mem;
  vp = &first_containing_mem;
  for (v = *vp; v != &dummy_val; v = next)
  for (v = *vp; v != &dummy_val; v = next)
    {
    {
      bool has_mem = false;
      bool has_mem = false;
      struct elt_loc_list **p = &v->locs;
      struct elt_loc_list **p = &v->locs;
      int had_locs = v->locs != 0;
      int had_locs = v->locs != 0;
 
 
      while (*p)
      while (*p)
        {
        {
          rtx x = (*p)->loc;
          rtx x = (*p)->loc;
          cselib_val *addr;
          cselib_val *addr;
          struct elt_list **mem_chain;
          struct elt_list **mem_chain;
 
 
          /* MEMs may occur in locations only at the top level; below
          /* MEMs may occur in locations only at the top level; below
             that every MEM or REG is substituted by its VALUE.  */
             that every MEM or REG is substituted by its VALUE.  */
          if (!MEM_P (x))
          if (!MEM_P (x))
            {
            {
              p = &(*p)->next;
              p = &(*p)->next;
              continue;
              continue;
            }
            }
          if (num_mems < PARAM_VALUE (PARAM_MAX_CSELIB_MEMORY_LOCATIONS)
          if (num_mems < PARAM_VALUE (PARAM_MAX_CSELIB_MEMORY_LOCATIONS)
              && ! canon_true_dependence (mem_rtx, GET_MODE (mem_rtx), mem_addr,
              && ! canon_true_dependence (mem_rtx, GET_MODE (mem_rtx), mem_addr,
                                          x, cselib_rtx_varies_p))
                                          x, cselib_rtx_varies_p))
            {
            {
              has_mem = true;
              has_mem = true;
              num_mems++;
              num_mems++;
              p = &(*p)->next;
              p = &(*p)->next;
              continue;
              continue;
            }
            }
 
 
          /* This one overlaps.  */
          /* This one overlaps.  */
          /* We must have a mapping from this MEM's address to the
          /* We must have a mapping from this MEM's address to the
             value (E).  Remove that, too.  */
             value (E).  Remove that, too.  */
          addr = cselib_lookup (XEXP (x, 0), VOIDmode, 0);
          addr = cselib_lookup (XEXP (x, 0), VOIDmode, 0);
          mem_chain = &addr->addr_list;
          mem_chain = &addr->addr_list;
          for (;;)
          for (;;)
            {
            {
              if ((*mem_chain)->elt == v)
              if ((*mem_chain)->elt == v)
                {
                {
                  unchain_one_elt_list (mem_chain);
                  unchain_one_elt_list (mem_chain);
                  break;
                  break;
                }
                }
 
 
              mem_chain = &(*mem_chain)->next;
              mem_chain = &(*mem_chain)->next;
            }
            }
 
 
          unchain_one_elt_loc_list (p);
          unchain_one_elt_loc_list (p);
        }
        }
 
 
      if (had_locs && v->locs == 0)
      if (had_locs && v->locs == 0)
        n_useless_values++;
        n_useless_values++;
 
 
      next = v->next_containing_mem;
      next = v->next_containing_mem;
      if (has_mem)
      if (has_mem)
        {
        {
          *vp = v;
          *vp = v;
          vp = &(*vp)->next_containing_mem;
          vp = &(*vp)->next_containing_mem;
        }
        }
      else
      else
        v->next_containing_mem = NULL;
        v->next_containing_mem = NULL;
    }
    }
  *vp = &dummy_val;
  *vp = &dummy_val;
}
}
 
 
/* Invalidate DEST, which is being assigned to or clobbered.  */
/* Invalidate DEST, which is being assigned to or clobbered.  */
 
 
void
void
cselib_invalidate_rtx (rtx dest)
cselib_invalidate_rtx (rtx dest)
{
{
  while (GET_CODE (dest) == SUBREG
  while (GET_CODE (dest) == SUBREG
         || GET_CODE (dest) == ZERO_EXTRACT
         || GET_CODE (dest) == ZERO_EXTRACT
         || GET_CODE (dest) == STRICT_LOW_PART)
         || GET_CODE (dest) == STRICT_LOW_PART)
    dest = XEXP (dest, 0);
    dest = XEXP (dest, 0);
 
 
  if (REG_P (dest))
  if (REG_P (dest))
    cselib_invalidate_regno (REGNO (dest), GET_MODE (dest));
    cselib_invalidate_regno (REGNO (dest), GET_MODE (dest));
  else if (MEM_P (dest))
  else if (MEM_P (dest))
    cselib_invalidate_mem (dest);
    cselib_invalidate_mem (dest);
 
 
  /* Some machines don't define AUTO_INC_DEC, but they still use push
  /* Some machines don't define AUTO_INC_DEC, but they still use push
     instructions.  We need to catch that case here in order to
     instructions.  We need to catch that case here in order to
     invalidate the stack pointer correctly.  Note that invalidating
     invalidate the stack pointer correctly.  Note that invalidating
     the stack pointer is different from invalidating DEST.  */
     the stack pointer is different from invalidating DEST.  */
  if (push_operand (dest, GET_MODE (dest)))
  if (push_operand (dest, GET_MODE (dest)))
    cselib_invalidate_rtx (stack_pointer_rtx);
    cselib_invalidate_rtx (stack_pointer_rtx);
}
}
 
 
/* A wrapper for cselib_invalidate_rtx to be called via note_stores.  */
/* A wrapper for cselib_invalidate_rtx to be called via note_stores.  */
 
 
static void
static void
cselib_invalidate_rtx_note_stores (rtx dest, rtx ignore ATTRIBUTE_UNUSED,
cselib_invalidate_rtx_note_stores (rtx dest, rtx ignore ATTRIBUTE_UNUSED,
                                   void *data ATTRIBUTE_UNUSED)
                                   void *data ATTRIBUTE_UNUSED)
{
{
  cselib_invalidate_rtx (dest);
  cselib_invalidate_rtx (dest);
}
}
 
 
/* Record the result of a SET instruction.  DEST is being set; the source
/* Record the result of a SET instruction.  DEST is being set; the source
   contains the value described by SRC_ELT.  If DEST is a MEM, DEST_ADDR_ELT
   contains the value described by SRC_ELT.  If DEST is a MEM, DEST_ADDR_ELT
   describes its address.  */
   describes its address.  */
 
 
static void
static void
cselib_record_set (rtx dest, cselib_val *src_elt, cselib_val *dest_addr_elt)
cselib_record_set (rtx dest, cselib_val *src_elt, cselib_val *dest_addr_elt)
{
{
  int dreg = REG_P (dest) ? (int) REGNO (dest) : -1;
  int dreg = REG_P (dest) ? (int) REGNO (dest) : -1;
 
 
  if (src_elt == 0 || side_effects_p (dest))
  if (src_elt == 0 || side_effects_p (dest))
    return;
    return;
 
 
  if (dreg >= 0)
  if (dreg >= 0)
    {
    {
      if (dreg < FIRST_PSEUDO_REGISTER)
      if (dreg < FIRST_PSEUDO_REGISTER)
        {
        {
          unsigned int n = hard_regno_nregs[dreg][GET_MODE (dest)];
          unsigned int n = hard_regno_nregs[dreg][GET_MODE (dest)];
 
 
          if (n > max_value_regs)
          if (n > max_value_regs)
            max_value_regs = n;
            max_value_regs = n;
        }
        }
 
 
      if (REG_VALUES (dreg) == 0)
      if (REG_VALUES (dreg) == 0)
        {
        {
          used_regs[n_used_regs++] = dreg;
          used_regs[n_used_regs++] = dreg;
          REG_VALUES (dreg) = new_elt_list (REG_VALUES (dreg), src_elt);
          REG_VALUES (dreg) = new_elt_list (REG_VALUES (dreg), src_elt);
        }
        }
      else
      else
        {
        {
          /* The register should have been invalidated.  */
          /* The register should have been invalidated.  */
          gcc_assert (REG_VALUES (dreg)->elt == 0);
          gcc_assert (REG_VALUES (dreg)->elt == 0);
          REG_VALUES (dreg)->elt = src_elt;
          REG_VALUES (dreg)->elt = src_elt;
        }
        }
 
 
      if (src_elt->locs == 0)
      if (src_elt->locs == 0)
        n_useless_values--;
        n_useless_values--;
      src_elt->locs = new_elt_loc_list (src_elt->locs, dest);
      src_elt->locs = new_elt_loc_list (src_elt->locs, dest);
    }
    }
  else if (MEM_P (dest) && dest_addr_elt != 0
  else if (MEM_P (dest) && dest_addr_elt != 0
           && cselib_record_memory)
           && cselib_record_memory)
    {
    {
      if (src_elt->locs == 0)
      if (src_elt->locs == 0)
        n_useless_values--;
        n_useless_values--;
      add_mem_for_addr (dest_addr_elt, src_elt, dest);
      add_mem_for_addr (dest_addr_elt, src_elt, dest);
    }
    }
}
}
 
 
/* Describe a single set that is part of an insn.  */
/* Describe a single set that is part of an insn.  */
struct set
struct set
{
{
  rtx src;
  rtx src;
  rtx dest;
  rtx dest;
  cselib_val *src_elt;
  cselib_val *src_elt;
  cselib_val *dest_addr_elt;
  cselib_val *dest_addr_elt;
};
};
 
 
/* There is no good way to determine how many elements there can be
/* There is no good way to determine how many elements there can be
   in a PARALLEL.  Since it's fairly cheap, use a really large number.  */
   in a PARALLEL.  Since it's fairly cheap, use a really large number.  */
#define MAX_SETS (FIRST_PSEUDO_REGISTER * 2)
#define MAX_SETS (FIRST_PSEUDO_REGISTER * 2)
 
 
/* Record the effects of any sets in INSN.  */
/* Record the effects of any sets in INSN.  */
static void
static void
cselib_record_sets (rtx insn)
cselib_record_sets (rtx insn)
{
{
  int n_sets = 0;
  int n_sets = 0;
  int i;
  int i;
  struct set sets[MAX_SETS];
  struct set sets[MAX_SETS];
  rtx body = PATTERN (insn);
  rtx body = PATTERN (insn);
  rtx cond = 0;
  rtx cond = 0;
 
 
  body = PATTERN (insn);
  body = PATTERN (insn);
  if (GET_CODE (body) == COND_EXEC)
  if (GET_CODE (body) == COND_EXEC)
    {
    {
      cond = COND_EXEC_TEST (body);
      cond = COND_EXEC_TEST (body);
      body = COND_EXEC_CODE (body);
      body = COND_EXEC_CODE (body);
    }
    }
 
 
  /* Find all sets.  */
  /* Find all sets.  */
  if (GET_CODE (body) == SET)
  if (GET_CODE (body) == SET)
    {
    {
      sets[0].src = SET_SRC (body);
      sets[0].src = SET_SRC (body);
      sets[0].dest = SET_DEST (body);
      sets[0].dest = SET_DEST (body);
      n_sets = 1;
      n_sets = 1;
    }
    }
  else if (GET_CODE (body) == PARALLEL)
  else if (GET_CODE (body) == PARALLEL)
    {
    {
      /* Look through the PARALLEL and record the values being
      /* Look through the PARALLEL and record the values being
         set, if possible.  Also handle any CLOBBERs.  */
         set, if possible.  Also handle any CLOBBERs.  */
      for (i = XVECLEN (body, 0) - 1; i >= 0; --i)
      for (i = XVECLEN (body, 0) - 1; i >= 0; --i)
        {
        {
          rtx x = XVECEXP (body, 0, i);
          rtx x = XVECEXP (body, 0, i);
 
 
          if (GET_CODE (x) == SET)
          if (GET_CODE (x) == SET)
            {
            {
              sets[n_sets].src = SET_SRC (x);
              sets[n_sets].src = SET_SRC (x);
              sets[n_sets].dest = SET_DEST (x);
              sets[n_sets].dest = SET_DEST (x);
              n_sets++;
              n_sets++;
            }
            }
        }
        }
    }
    }
 
 
  /* Look up the values that are read.  Do this before invalidating the
  /* Look up the values that are read.  Do this before invalidating the
     locations that are written.  */
     locations that are written.  */
  for (i = 0; i < n_sets; i++)
  for (i = 0; i < n_sets; i++)
    {
    {
      rtx dest = sets[i].dest;
      rtx dest = sets[i].dest;
 
 
      /* A STRICT_LOW_PART can be ignored; we'll record the equivalence for
      /* A STRICT_LOW_PART can be ignored; we'll record the equivalence for
         the low part after invalidating any knowledge about larger modes.  */
         the low part after invalidating any knowledge about larger modes.  */
      if (GET_CODE (sets[i].dest) == STRICT_LOW_PART)
      if (GET_CODE (sets[i].dest) == STRICT_LOW_PART)
        sets[i].dest = dest = XEXP (dest, 0);
        sets[i].dest = dest = XEXP (dest, 0);
 
 
      /* We don't know how to record anything but REG or MEM.  */
      /* We don't know how to record anything but REG or MEM.  */
      if (REG_P (dest)
      if (REG_P (dest)
          || (MEM_P (dest) && cselib_record_memory))
          || (MEM_P (dest) && cselib_record_memory))
        {
        {
          rtx src = sets[i].src;
          rtx src = sets[i].src;
          if (cond)
          if (cond)
            src = gen_rtx_IF_THEN_ELSE (GET_MODE (src), cond, src, dest);
            src = gen_rtx_IF_THEN_ELSE (GET_MODE (src), cond, src, dest);
          sets[i].src_elt = cselib_lookup (src, GET_MODE (dest), 1);
          sets[i].src_elt = cselib_lookup (src, GET_MODE (dest), 1);
          if (MEM_P (dest))
          if (MEM_P (dest))
            sets[i].dest_addr_elt = cselib_lookup (XEXP (dest, 0), Pmode, 1);
            sets[i].dest_addr_elt = cselib_lookup (XEXP (dest, 0), Pmode, 1);
          else
          else
            sets[i].dest_addr_elt = 0;
            sets[i].dest_addr_elt = 0;
        }
        }
    }
    }
 
 
  /* Invalidate all locations written by this insn.  Note that the elts we
  /* Invalidate all locations written by this insn.  Note that the elts we
     looked up in the previous loop aren't affected, just some of their
     looked up in the previous loop aren't affected, just some of their
     locations may go away.  */
     locations may go away.  */
  note_stores (body, cselib_invalidate_rtx_note_stores, NULL);
  note_stores (body, cselib_invalidate_rtx_note_stores, NULL);
 
 
  /* If this is an asm, look for duplicate sets.  This can happen when the
  /* If this is an asm, look for duplicate sets.  This can happen when the
     user uses the same value as an output multiple times.  This is valid
     user uses the same value as an output multiple times.  This is valid
     if the outputs are not actually used thereafter.  Treat this case as
     if the outputs are not actually used thereafter.  Treat this case as
     if the value isn't actually set.  We do this by smashing the destination
     if the value isn't actually set.  We do this by smashing the destination
     to pc_rtx, so that we won't record the value later.  */
     to pc_rtx, so that we won't record the value later.  */
  if (n_sets >= 2 && asm_noperands (body) >= 0)
  if (n_sets >= 2 && asm_noperands (body) >= 0)
    {
    {
      for (i = 0; i < n_sets; i++)
      for (i = 0; i < n_sets; i++)
        {
        {
          rtx dest = sets[i].dest;
          rtx dest = sets[i].dest;
          if (REG_P (dest) || MEM_P (dest))
          if (REG_P (dest) || MEM_P (dest))
            {
            {
              int j;
              int j;
              for (j = i + 1; j < n_sets; j++)
              for (j = i + 1; j < n_sets; j++)
                if (rtx_equal_p (dest, sets[j].dest))
                if (rtx_equal_p (dest, sets[j].dest))
                  {
                  {
                    sets[i].dest = pc_rtx;
                    sets[i].dest = pc_rtx;
                    sets[j].dest = pc_rtx;
                    sets[j].dest = pc_rtx;
                  }
                  }
            }
            }
        }
        }
    }
    }
 
 
  /* Now enter the equivalences in our tables.  */
  /* Now enter the equivalences in our tables.  */
  for (i = 0; i < n_sets; i++)
  for (i = 0; i < n_sets; i++)
    {
    {
      rtx dest = sets[i].dest;
      rtx dest = sets[i].dest;
      if (REG_P (dest)
      if (REG_P (dest)
          || (MEM_P (dest) && cselib_record_memory))
          || (MEM_P (dest) && cselib_record_memory))
        cselib_record_set (dest, sets[i].src_elt, sets[i].dest_addr_elt);
        cselib_record_set (dest, sets[i].src_elt, sets[i].dest_addr_elt);
    }
    }
}
}
 
 
/* Record the effects of INSN.  */
/* Record the effects of INSN.  */
 
 
void
void
cselib_process_insn (rtx insn)
cselib_process_insn (rtx insn)
{
{
  int i;
  int i;
  rtx x;
  rtx x;
 
 
  if (find_reg_note (insn, REG_LIBCALL, NULL))
  if (find_reg_note (insn, REG_LIBCALL, NULL))
    cselib_current_insn_in_libcall = true;
    cselib_current_insn_in_libcall = true;
  cselib_current_insn = insn;
  cselib_current_insn = insn;
 
 
  /* Forget everything at a CODE_LABEL, a volatile asm, or a setjmp.  */
  /* Forget everything at a CODE_LABEL, a volatile asm, or a setjmp.  */
  if (LABEL_P (insn)
  if (LABEL_P (insn)
      || (CALL_P (insn)
      || (CALL_P (insn)
          && find_reg_note (insn, REG_SETJMP, NULL))
          && find_reg_note (insn, REG_SETJMP, NULL))
      || (NONJUMP_INSN_P (insn)
      || (NONJUMP_INSN_P (insn)
          && GET_CODE (PATTERN (insn)) == ASM_OPERANDS
          && GET_CODE (PATTERN (insn)) == ASM_OPERANDS
          && MEM_VOLATILE_P (PATTERN (insn))))
          && MEM_VOLATILE_P (PATTERN (insn))))
    {
    {
      if (find_reg_note (insn, REG_RETVAL, NULL))
      if (find_reg_note (insn, REG_RETVAL, NULL))
        cselib_current_insn_in_libcall = false;
        cselib_current_insn_in_libcall = false;
      cselib_clear_table ();
      cselib_clear_table ();
      return;
      return;
    }
    }
 
 
  if (! INSN_P (insn))
  if (! INSN_P (insn))
    {
    {
      if (find_reg_note (insn, REG_RETVAL, NULL))
      if (find_reg_note (insn, REG_RETVAL, NULL))
        cselib_current_insn_in_libcall = false;
        cselib_current_insn_in_libcall = false;
      cselib_current_insn = 0;
      cselib_current_insn = 0;
      return;
      return;
    }
    }
 
 
  /* If this is a call instruction, forget anything stored in a
  /* If this is a call instruction, forget anything stored in a
     call clobbered register, or, if this is not a const call, in
     call clobbered register, or, if this is not a const call, in
     memory.  */
     memory.  */
  if (CALL_P (insn))
  if (CALL_P (insn))
    {
    {
      for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
      for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
        if (call_used_regs[i]
        if (call_used_regs[i]
            || (REG_VALUES (i) && REG_VALUES (i)->elt
            || (REG_VALUES (i) && REG_VALUES (i)->elt
                && HARD_REGNO_CALL_PART_CLOBBERED (i,
                && HARD_REGNO_CALL_PART_CLOBBERED (i,
                      GET_MODE (REG_VALUES (i)->elt->u.val_rtx))))
                      GET_MODE (REG_VALUES (i)->elt->u.val_rtx))))
          cselib_invalidate_regno (i, reg_raw_mode[i]);
          cselib_invalidate_regno (i, reg_raw_mode[i]);
 
 
      if (! CONST_OR_PURE_CALL_P (insn))
      if (! CONST_OR_PURE_CALL_P (insn))
        cselib_invalidate_mem (callmem);
        cselib_invalidate_mem (callmem);
    }
    }
 
 
  cselib_record_sets (insn);
  cselib_record_sets (insn);
 
 
#ifdef AUTO_INC_DEC
#ifdef AUTO_INC_DEC
  /* Clobber any registers which appear in REG_INC notes.  We
  /* Clobber any registers which appear in REG_INC notes.  We
     could keep track of the changes to their values, but it is
     could keep track of the changes to their values, but it is
     unlikely to help.  */
     unlikely to help.  */
  for (x = REG_NOTES (insn); x; x = XEXP (x, 1))
  for (x = REG_NOTES (insn); x; x = XEXP (x, 1))
    if (REG_NOTE_KIND (x) == REG_INC)
    if (REG_NOTE_KIND (x) == REG_INC)
      cselib_invalidate_rtx (XEXP (x, 0));
      cselib_invalidate_rtx (XEXP (x, 0));
#endif
#endif
 
 
  /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only
  /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only
     after we have processed the insn.  */
     after we have processed the insn.  */
  if (CALL_P (insn))
  if (CALL_P (insn))
    for (x = CALL_INSN_FUNCTION_USAGE (insn); x; x = XEXP (x, 1))
    for (x = CALL_INSN_FUNCTION_USAGE (insn); x; x = XEXP (x, 1))
      if (GET_CODE (XEXP (x, 0)) == CLOBBER)
      if (GET_CODE (XEXP (x, 0)) == CLOBBER)
        cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0));
        cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0));
 
 
  if (find_reg_note (insn, REG_RETVAL, NULL))
  if (find_reg_note (insn, REG_RETVAL, NULL))
    cselib_current_insn_in_libcall = false;
    cselib_current_insn_in_libcall = false;
  cselib_current_insn = 0;
  cselib_current_insn = 0;
 
 
  if (n_useless_values > MAX_USELESS_VALUES
  if (n_useless_values > MAX_USELESS_VALUES
      /* remove_useless_values is linear in the hash table size.  Avoid
      /* remove_useless_values is linear in the hash table size.  Avoid
         quadratic behaviour for very large hashtables with very few
         quadratic behaviour for very large hashtables with very few
         useless elements.  */
         useless elements.  */
      && (unsigned int)n_useless_values > cselib_hash_table->n_elements / 4)
      && (unsigned int)n_useless_values > cselib_hash_table->n_elements / 4)
    remove_useless_values ();
    remove_useless_values ();
}
}
 
 
/* Initialize cselib for one pass.  The caller must also call
/* Initialize cselib for one pass.  The caller must also call
   init_alias_analysis.  */
   init_alias_analysis.  */
 
 
void
void
cselib_init (bool record_memory)
cselib_init (bool record_memory)
{
{
  elt_list_pool = create_alloc_pool ("elt_list",
  elt_list_pool = create_alloc_pool ("elt_list",
                                     sizeof (struct elt_list), 10);
                                     sizeof (struct elt_list), 10);
  elt_loc_list_pool = create_alloc_pool ("elt_loc_list",
  elt_loc_list_pool = create_alloc_pool ("elt_loc_list",
                                         sizeof (struct elt_loc_list), 10);
                                         sizeof (struct elt_loc_list), 10);
  cselib_val_pool = create_alloc_pool ("cselib_val_list",
  cselib_val_pool = create_alloc_pool ("cselib_val_list",
                                       sizeof (cselib_val), 10);
                                       sizeof (cselib_val), 10);
  value_pool = create_alloc_pool ("value", RTX_CODE_SIZE (VALUE), 100);
  value_pool = create_alloc_pool ("value", RTX_CODE_SIZE (VALUE), 100);
  cselib_record_memory = record_memory;
  cselib_record_memory = record_memory;
  /* This is only created once.  */
  /* This is only created once.  */
  if (! callmem)
  if (! callmem)
    callmem = gen_rtx_MEM (BLKmode, const0_rtx);
    callmem = gen_rtx_MEM (BLKmode, const0_rtx);
 
 
  cselib_nregs = max_reg_num ();
  cselib_nregs = max_reg_num ();
 
 
  /* We preserve reg_values to allow expensive clearing of the whole thing.
  /* We preserve reg_values to allow expensive clearing of the whole thing.
     Reallocate it however if it happens to be too large.  */
     Reallocate it however if it happens to be too large.  */
  if (!reg_values || reg_values_size < cselib_nregs
  if (!reg_values || reg_values_size < cselib_nregs
      || (reg_values_size > 10 && reg_values_size > cselib_nregs * 4))
      || (reg_values_size > 10 && reg_values_size > cselib_nregs * 4))
    {
    {
      if (reg_values)
      if (reg_values)
        free (reg_values);
        free (reg_values);
      /* Some space for newly emit instructions so we don't end up
      /* Some space for newly emit instructions so we don't end up
         reallocating in between passes.  */
         reallocating in between passes.  */
      reg_values_size = cselib_nregs + (63 + cselib_nregs) / 16;
      reg_values_size = cselib_nregs + (63 + cselib_nregs) / 16;
      reg_values = XCNEWVEC (struct elt_list *, reg_values_size);
      reg_values = XCNEWVEC (struct elt_list *, reg_values_size);
    }
    }
  used_regs = XNEWVEC (unsigned int, cselib_nregs);
  used_regs = XNEWVEC (unsigned int, cselib_nregs);
  n_used_regs = 0;
  n_used_regs = 0;
  cselib_hash_table = htab_create (31, get_value_hash,
  cselib_hash_table = htab_create (31, get_value_hash,
                                   entry_and_rtx_equal_p, NULL);
                                   entry_and_rtx_equal_p, NULL);
  cselib_current_insn_in_libcall = false;
  cselib_current_insn_in_libcall = false;
}
}
 
 
/* Called when the current user is done with cselib.  */
/* Called when the current user is done with cselib.  */
 
 
void
void
cselib_finish (void)
cselib_finish (void)
{
{
  free_alloc_pool (elt_list_pool);
  free_alloc_pool (elt_list_pool);
  free_alloc_pool (elt_loc_list_pool);
  free_alloc_pool (elt_loc_list_pool);
  free_alloc_pool (cselib_val_pool);
  free_alloc_pool (cselib_val_pool);
  free_alloc_pool (value_pool);
  free_alloc_pool (value_pool);
  cselib_clear_table ();
  cselib_clear_table ();
  htab_delete (cselib_hash_table);
  htab_delete (cselib_hash_table);
  free (used_regs);
  free (used_regs);
  used_regs = 0;
  used_regs = 0;
  cselib_hash_table = 0;
  cselib_hash_table = 0;
  n_useless_values = 0;
  n_useless_values = 0;
  next_unknown_value = 0;
  next_unknown_value = 0;
}
}
 
 
#include "gt-cselib.h"
#include "gt-cselib.h"
 
 

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