Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
Contributed by John Carr (jfc@mit.edu).
-This file is part of GNU CC.
+This file is part of GCC.
-GNU CC 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 Software Foundation; either version 2, or (at your option)
-any later version.
+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
+Software Foundation; either version 2, or (at your option) any later
+version.
-GNU CC is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-GNU General Public License for more details.
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+for more details.
You should have received a copy of the GNU General Public License
-along with GNU CC; see the file COPYING. If not, write to
-the Free Software Foundation, 59 Temple Place - Suite 330,
-Boston, MA 02111-1307, USA. */
+along with GCC; see the file COPYING. If not, write to the Free
+Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+02111-1307, USA. */
#include "config.h"
#include "system.h"
To see whether two alias sets can point to the same memory, we must
see if either alias set is a subset of the other. We need not trace
- past immediate decendents, however, since we propagate all
+ past immediate descendents, however, since we propagate all
grandchildren up one level.
Alias set zero is implicitly a superset of all other alias sets.
HOST_WIDE_INT alias_set;
/* The children of the alias set. These are not just the immediate
- children, but, in fact, all decendents. So, if we have:
+ children, but, in fact, all descendents. So, if we have:
struct T { struct S s; float f; }
static rtx find_base_value PARAMS ((rtx));
static int mems_in_disjoint_alias_sets_p PARAMS ((rtx, rtx));
static int insert_subset_children PARAMS ((splay_tree_node, void*));
-static tree find_base_decl PARAMS ((tree));
+static tree find_base_decl PARAMS ((tree));
static alias_set_entry get_alias_set_entry PARAMS ((HOST_WIDE_INT));
static rtx fixed_scalar_and_varying_struct_p PARAMS ((rtx, rtx, rtx, rtx,
int (*) (rtx, int)));
return 0;
}
\f
-/* Set the alias set of MEM to SET. */
-
-void
-set_mem_alias_set (mem, set)
- rtx mem;
- HOST_WIDE_INT set;
-{
- /* We would like to do this test but can't yet since when converting a
- REG to a MEM, the alias set field is undefined. */
-#if 0
- /* If the new and old alias sets don't conflict, something is wrong. */
- if (!alias_sets_conflict_p (set, MEM_ALIAS_SET (mem)))
- abort ();
-#endif
-
- MEM_ALIAS_SET (mem) = set;
-}
-\f
/* Return 1 if TYPE is a RECORD_TYPE, UNION_TYPE, or QUAL_UNION_TYPE and has
has any readonly fields. If any of the fields have types that
contain readonly fields, return true as well. */
case '3':
d0 = find_base_decl (TREE_OPERAND (t, 0));
d1 = find_base_decl (TREE_OPERAND (t, 1));
- d0 = find_base_decl (TREE_OPERAND (t, 0));
d2 = find_base_decl (TREE_OPERAND (t, 2));
/* Set any nonzero values from the last, then from the first. */
get_alias_set (t)
tree t;
{
- tree orig_t;
HOST_WIDE_INT set;
/* If we're not doing any alias analysis, just assume everything
return 0;
/* We can be passed either an expression or a type. This and the
- language-specific routine may make mutually-recursive calls to
- each other to figure out what to do. At each juncture, we see if
- this is a tree that the language may need to handle specially.
- First handle things that aren't types and start by removing nops
- since we care only about the actual object. */
+ language-specific routine may make mutually-recursive calls to each other
+ to figure out what to do. At each juncture, we see if this is a tree
+ that the language may need to handle specially. First handle things that
+ aren't types. */
if (! TYPE_P (t))
{
- while (TREE_CODE (t) == NOP_EXPR || TREE_CODE (t) == CONVERT_EXPR
- || TREE_CODE (t) == NON_LVALUE_EXPR)
- t = TREE_OPERAND (t, 0);
-
- /* Now give the language a chance to do something but record what we
- gave it this time. */
- orig_t = t;
- if ((set = lang_get_alias_set (t)) != -1)
- return set;
-
- /* Now loop the same way as get_inner_reference and get the alias
- set to use. Pick up the outermost object that we could have
- a pointer to. */
- while (handled_component_p (t) && ! can_address_p (t))
- t = TREE_OPERAND (t, 0);
+ tree inner = t;
+ tree placeholder_ptr = 0;
+
+ /* First see if the actual object referenced is an INDIRECT_REF from a
+ restrict-qualified pointer or a "void *". Start by removing nops
+ since we care only about the actual object. Also replace
+ PLACEHOLDER_EXPRs. */
+ while (((TREE_CODE (inner) == NOP_EXPR
+ || TREE_CODE (inner) == CONVERT_EXPR)
+ && (TYPE_MODE (TREE_TYPE (inner))
+ == TYPE_MODE (TREE_TYPE (TREE_OPERAND (inner, 0)))))
+ || TREE_CODE (inner) == NON_LVALUE_EXPR
+ || TREE_CODE (inner) == PLACEHOLDER_EXPR
+ || handled_component_p (inner))
+ {
+ if (TREE_CODE (inner) == PLACEHOLDER_EXPR)
+ inner = find_placeholder (inner, &placeholder_ptr);
+ else
+ inner = TREE_OPERAND (inner, 0);
+ }
- if (TREE_CODE (t) == INDIRECT_REF)
+ /* Check for accesses through restrict-qualified pointers. */
+ if (TREE_CODE (inner) == INDIRECT_REF)
{
- /* Check for accesses through restrict-qualified pointers. */
- tree decl = find_base_decl (TREE_OPERAND (t, 0));
+ tree decl = find_base_decl (TREE_OPERAND (inner, 0));
if (decl && DECL_POINTER_ALIAS_SET_KNOWN_P (decl))
- /* We use the alias set indicated in the declaration. */
- return DECL_POINTER_ALIAS_SET (decl);
+ {
+ /* If we haven't computed the actual alias set, do it now. */
+ if (DECL_POINTER_ALIAS_SET (decl) == -2)
+ {
+ /* No two restricted pointers can point at the same thing.
+ However, a restricted pointer can point at the same thing
+ as an unrestricted pointer, if that unrestricted pointer
+ is based on the restricted pointer. So, we make the
+ alias set for the restricted pointer a subset of the
+ alias set for the type pointed to by the type of the
+ decl. */
+ HOST_WIDE_INT pointed_to_alias_set
+ = get_alias_set (TREE_TYPE (TREE_TYPE (decl)));
+
+ if (pointed_to_alias_set == 0)
+ /* It's not legal to make a subset of alias set zero. */
+ ;
+ else
+ {
+ DECL_POINTER_ALIAS_SET (decl) = new_alias_set ();
+ record_alias_subset (pointed_to_alias_set,
+ DECL_POINTER_ALIAS_SET (decl));
+ }
+ }
+
+ /* We use the alias set indicated in the declaration. */
+ return DECL_POINTER_ALIAS_SET (decl);
+ }
/* If we have an INDIRECT_REF via a void pointer, we don't
know anything about what that might alias. */
- if (TREE_CODE (TREE_TYPE (t)) == VOID_TYPE)
+ else if (TREE_CODE (TREE_TYPE (inner)) == VOID_TYPE)
return 0;
}
- /* Give the language another chance to do something special. */
- if (orig_t != t
- && (set = lang_get_alias_set (t)) != -1)
+ /* Otherwise, pick up the outermost object that we could have a pointer
+ to, processing conversion and PLACEHOLDER_EXPR as above. */
+ placeholder_ptr = 0;
+ while (((TREE_CODE (t) == NOP_EXPR || TREE_CODE (t) == CONVERT_EXPR)
+ && (TYPE_MODE (TREE_TYPE (t))
+ == TYPE_MODE (TREE_TYPE (TREE_OPERAND (t, 0)))))
+ || TREE_CODE (t) == NON_LVALUE_EXPR
+ || TREE_CODE (t) == PLACEHOLDER_EXPR
+ || (handled_component_p (t) && ! can_address_p (t)))
+ {
+ /* Give the language a chance to do something with this tree
+ before we go inside it. */
+ if ((set = lang_get_alias_set (t)) != -1)
+ return set;
+
+ if (TREE_CODE (t) == PLACEHOLDER_EXPR)
+ t = find_placeholder (t, &placeholder_ptr);
+ else
+ t = TREE_OPERAND (t, 0);
+ }
+
+ /* Give the language another chance to do something. */
+ if ((set = lang_get_alias_set (t)) != -1)
return set;
+ /* If we've already determined the alias set for a decl, just return
+ it. This is necessary for C++ anonymous unions, whose component
+ variables don't look like union members (boo!). */
+ if (TREE_CODE (t) == VAR_DECL
+ && DECL_RTL_SET_P (t) && GET_CODE (DECL_RTL (t)) == MEM)
+ return MEM_ALIAS_SET (DECL_RTL (t));
+
/* Now all we care about is the type. */
t = TREE_TYPE (t);
}
/* Variant qualifiers don't affect the alias set, so get the main
variant. If this is a type with a known alias set, return it. */
t = TYPE_MAIN_VARIANT (t);
- if (TYPE_P (t) && TYPE_ALIAS_SET_KNOWN_P (t))
+ if (TYPE_ALIAS_SET_KNOWN_P (t))
return TYPE_ALIAS_SET (t);
/* See if the language has special handling for this type. */
if ((set = lang_get_alias_set (t)) != -1)
- {
- /* If the alias set is now known, we are done. */
- if (TYPE_ALIAS_SET_KNOWN_P (t))
- return TYPE_ALIAS_SET (t);
- }
+ return set;
/* There are no objects of FUNCTION_TYPE, so there's no point in
using up an alias set for them. (There are, of course, pointers
alias_set_entry superset_entry;
alias_set_entry subset_entry;
+ /* It is possible in complex type situations for both sets to be the same,
+ in which case we can ignore this operation. */
+ if (superset == subset)
+ return;
+
if (superset == 0)
abort ();
static rtx
find_base_value (src)
- register rtx src;
+ rtx src;
{
unsigned int regno;
switch (GET_CODE (src))
rtx dest, set;
void *data ATTRIBUTE_UNUSED;
{
- register unsigned regno;
+ unsigned regno;
rtx src;
if (GET_CODE (dest) != REG)
reg_base_value[regno] = find_base_value (val);
}
+/* Clear alias info for a register. This is used if an RTL transformation
+ changes the value of a register. This is used in flow by AUTO_INC_DEC
+ optimizations. We don't need to clear reg_base_value, since flow only
+ changes the offset. */
+
+void
+clear_reg_alias_info (reg)
+ rtx reg;
+{
+ unsigned int regno = REGNO (reg);
+
+ if (regno < reg_known_value_size && regno >= FIRST_PSEUDO_REGISTER)
+ reg_known_value[regno] = reg;
+}
+
/* Returns a canonical version of X, from the point of view alias
analysis. (For example, if X is a MEM whose address is a register,
and the register has a known value (say a SYMBOL_REF), then a MEM
rtx_equal_for_memref_p (x, y)
rtx x, y;
{
- register int i;
- register int j;
- register enum rtx_code code;
- register const char *fmt;
+ int i;
+ int j;
+ enum rtx_code code;
+ const char *fmt;
if (x == 0 && y == 0)
return 1;
find_symbolic_term (x)
rtx x;
{
- register int i;
- register enum rtx_code code;
- register const char *fmt;
+ int i;
+ enum rtx_code code;
+ const char *fmt;
code = GET_CODE (x);
if (code == SYMBOL_REF || code == LABEL_REF)
static rtx
find_base_term (x)
- register rtx x;
+ rtx x;
{
cselib_val *val;
struct elt_loc_list *l;
static int
memrefs_conflict_p (xsize, x, ysize, y, c)
- register rtx x, y;
+ rtx x, y;
int xsize, ysize;
HOST_WIDE_INT c;
{
rtx x;
int (*varies) PARAMS ((rtx, int));
{
- register rtx x_addr, mem_addr;
+ rtx x_addr, mem_addr;
rtx base;
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
enum machine_mode mem_mode;
int (*varies) PARAMS ((rtx, int));
{
- register rtx x_addr;
+ rtx x_addr;
if (MEM_VOLATILE_P (x) && MEM_VOLATILE_P (mem))
return 1;
int
output_dependence (mem, x)
- register rtx mem;
- register rtx x;
+ rtx mem;
+ rtx x;
{
return write_dependence_p (mem, x, /*writep=*/1);
}
rtx x;
{
rtx base;
- register RTX_CODE code;
+ RTX_CODE code;
int regno;
code = GET_CODE (x);
{
/* Constant functions can be constant if they don't use
scratch memory used to mark function w/o side effects. */
- if (code == CALL_INSN && CONST_CALL_P (x))
+ if (code == CALL_INSN && CONST_OR_PURE_CALL_P (x))
{
x = CALL_INSN_FUNCTION_USAGE (x);
if (x == 0)
/* Recursively scan the operands of this expression. */
{
- register const char *fmt = GET_RTX_FORMAT (code);
- register int i;
+ const char *fmt = GET_RTX_FORMAT (code);
+ int i;
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
{
}
else if (fmt[i] == 'E')
{
- register int j;
+ int j;
for (j = 0; j < XVECLEN (x, i); j++)
if (nonlocal_mentioned_p (XVECEXP (x, i, j)))
return 1;
void
init_alias_once ()
{
- register int i;
+ int i;
#ifndef OUTGOING_REGNO
#define OUTGOING_REGNO(N) N
{
int maxreg = max_reg_num ();
int changed, pass;
- register int i;
- register unsigned int ui;
- register rtx insn;
+ int i;
+ unsigned int ui;
+ rtx insn;
reg_known_value_size = maxreg;
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