/* Alias analysis for GNU C
Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,
- 2007, 2008, 2009 Free Software Foundation, Inc.
+ 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
Contributed by John Carr (jfc@mit.edu).
This file is part of GCC.
#include "timevar.h"
#include "target.h"
#include "cgraph.h"
-#include "varray.h"
#include "tree-pass.h"
#include "ipa-type-escape.h"
#include "df.h"
if (!expr)
return false;
- /* If MEM_OFFSET or MEM_SIZE are NULL punt. */
- if (!MEM_OFFSET (mem)
- || !MEM_SIZE (mem))
- return false;
-
ao_ref_init (ref, expr);
/* Get the base of the reference and see if we have to reject or
if (base == NULL_TREE)
return false;
+ /* The tree oracle doesn't like to have these. */
+ if (TREE_CODE (base) == FUNCTION_DECL
+ || TREE_CODE (base) == LABEL_DECL)
+ return false;
+
/* If this is a pointer dereference of a non-SSA_NAME punt.
??? We could replace it with a pointer to anything. */
if (INDIRECT_REF_P (base)
&& TREE_CODE (TREE_OPERAND (base, 0)) != SSA_NAME)
return false;
- /* The tree oracle doesn't like to have these. */
- if (TREE_CODE (base) == FUNCTION_DECL
- || TREE_CODE (base) == LABEL_DECL)
- return false;
-
/* If this is a reference based on a partitioned decl replace the
base with an INDIRECT_REF of the pointer representative we
created during stack slot partitioning. */
ref->ref_alias_set = MEM_ALIAS_SET (mem);
+ /* If MEM_OFFSET or MEM_SIZE are NULL we have to punt.
+ Keep points-to related information though. */
+ if (!MEM_OFFSET (mem)
+ || !MEM_SIZE (mem))
+ {
+ ref->ref = NULL_TREE;
+ ref->offset = 0;
+ ref->size = -1;
+ ref->max_size = -1;
+ return true;
+ }
+
/* If the base decl is a parameter we can have negative MEM_OFFSET in
case of promoted subregs on bigendian targets. Trust the MEM_EXPR
here. */
/* Otherwise, check if set1 is a subset of set2. */
ase = get_alias_set_entry (set2);
if (ase != 0
- && ((ase->has_zero_child && set1 == 0)
+ && (ase->has_zero_child
|| splay_tree_lookup (ase->children,
(splay_tree_key) set1)))
return true;
|| (GET_CODE (y_base) == ADDRESS && GET_MODE (y_base) == Pmode))
return 0;
- if (! flag_argument_noalias)
- return 1;
-
- if (flag_argument_noalias > 1)
- return 0;
-
- /* Weak noalias assertion (arguments are distinct, but may match globals). */
- return ! (GET_MODE (x_base) == VOIDmode && GET_MODE (y_base) == VOIDmode);
+ return 1;
}
/* Convert the address X into something we can use. This is done by returning
memrefs_conflict_p (int xsize, rtx x, int ysize, rtx y, HOST_WIDE_INT c)
{
if (GET_CODE (x) == VALUE)
- x = get_addr (x);
+ {
+ if (REG_P (y))
+ {
+ struct elt_loc_list *l = NULL;
+ if (CSELIB_VAL_PTR (x))
+ for (l = CSELIB_VAL_PTR (x)->locs; l; l = l->next)
+ if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, y))
+ break;
+ if (l)
+ x = y;
+ else
+ x = get_addr (x);
+ }
+ /* Don't call get_addr if y is the same VALUE. */
+ else if (x != y)
+ x = get_addr (x);
+ }
if (GET_CODE (y) == VALUE)
- y = get_addr (y);
+ {
+ if (REG_P (x))
+ {
+ struct elt_loc_list *l = NULL;
+ if (CSELIB_VAL_PTR (y))
+ for (l = CSELIB_VAL_PTR (y)->locs; l; l = l->next)
+ if (REG_P (l->loc) && rtx_equal_for_memref_p (l->loc, x))
+ break;
+ if (l)
+ y = x;
+ else
+ y = get_addr (y);
+ }
+ /* Don't call get_addr if x is the same VALUE. */
+ else if (y != x)
+ y = get_addr (y);
+ }
if (GET_CODE (x) == HIGH)
x = XEXP (x, 0);
else if (GET_CODE (x) == LO_SUM)
if (exprx == 0 || expry == 0)
return 0;
+ /* For spill-slot accesses make sure we have valid offsets. */
+ if ((exprx == get_spill_slot_decl (false)
+ && ! MEM_OFFSET (x))
+ || (expry == get_spill_slot_decl (false)
+ && ! MEM_OFFSET (y)))
+ return 0;
+
/* If both are field references, we may be able to determine something. */
if (TREE_CODE (exprx) == COMPONENT_REF
&& TREE_CODE (expry) == COMPONENT_REF
moffsetx = MEM_OFFSET (x);
if (TREE_CODE (exprx) == COMPONENT_REF)
{
- if (TREE_CODE (expry) == VAR_DECL
- && POINTER_TYPE_P (TREE_TYPE (expry)))
- {
- tree field = TREE_OPERAND (exprx, 1);
- tree fieldcontext = DECL_FIELD_CONTEXT (field);
- if (ipa_type_escape_field_does_not_clobber_p (fieldcontext,
- TREE_TYPE (field)))
- return 1;
- }
- {
- tree t = decl_for_component_ref (exprx);
- if (! t)
- return 0;
- moffsetx = adjust_offset_for_component_ref (exprx, moffsetx);
- exprx = t;
- }
- }
- else if (INDIRECT_REF_P (exprx))
- {
- exprx = TREE_OPERAND (exprx, 0);
- if (flag_argument_noalias < 2
- || TREE_CODE (exprx) != PARM_DECL)
+ tree t = decl_for_component_ref (exprx);
+ if (! t)
return 0;
+ moffsetx = adjust_offset_for_component_ref (exprx, moffsetx);
+ exprx = t;
}
moffsety = MEM_OFFSET (y);
if (TREE_CODE (expry) == COMPONENT_REF)
{
- if (TREE_CODE (exprx) == VAR_DECL
- && POINTER_TYPE_P (TREE_TYPE (exprx)))
- {
- tree field = TREE_OPERAND (expry, 1);
- tree fieldcontext = DECL_FIELD_CONTEXT (field);
- if (ipa_type_escape_field_does_not_clobber_p (fieldcontext,
- TREE_TYPE (field)))
- return 1;
- }
- {
- tree t = decl_for_component_ref (expry);
- if (! t)
- return 0;
- moffsety = adjust_offset_for_component_ref (expry, moffsety);
- expry = t;
- }
- }
- else if (INDIRECT_REF_P (expry))
- {
- expry = TREE_OPERAND (expry, 0);
- if (flag_argument_noalias < 2
- || TREE_CODE (expry) != PARM_DECL)
+ tree t = decl_for_component_ref (expry);
+ if (! t)
return 0;
+ moffsety = adjust_offset_for_component_ref (expry, moffsety);
+ expry = t;
}
if (! DECL_P (exprx) || ! DECL_P (expry))
if (mem_mode == VOIDmode)
mem_mode = GET_MODE (mem);
- x_addr = get_addr (XEXP (x, 0));
- mem_addr = get_addr (XEXP (mem, 0));
+ x_addr = XEXP (x, 0);
+ mem_addr = XEXP (mem, 0);
+ if (!((GET_CODE (x_addr) == VALUE
+ && GET_CODE (mem_addr) != VALUE
+ && reg_mentioned_p (x_addr, mem_addr))
+ || (GET_CODE (x_addr) != VALUE
+ && GET_CODE (mem_addr) == VALUE
+ && reg_mentioned_p (mem_addr, x_addr))))
+ {
+ x_addr = get_addr (x_addr);
+ mem_addr = get_addr (mem_addr);
+ }
base = find_base_term (x_addr);
if (base && (GET_CODE (base) == LABEL_REF
return 1;
if (! x_addr)
- x_addr = get_addr (XEXP (x, 0));
+ {
+ x_addr = XEXP (x, 0);
+ if (!((GET_CODE (x_addr) == VALUE
+ && GET_CODE (mem_addr) != VALUE
+ && reg_mentioned_p (x_addr, mem_addr))
+ || (GET_CODE (x_addr) != VALUE
+ && GET_CODE (mem_addr) == VALUE
+ && reg_mentioned_p (mem_addr, x_addr))))
+ x_addr = get_addr (x_addr);
+ }
if (! base_alias_check (x_addr, mem_addr, GET_MODE (x), mem_mode))
return 0;
if (MEM_ADDR_SPACE (mem) != MEM_ADDR_SPACE (x))
return 1;
- x_addr = get_addr (XEXP (x, 0));
- mem_addr = get_addr (XEXP (mem, 0));
+ x_addr = XEXP (x, 0);
+ mem_addr = XEXP (mem, 0);
+ if (!((GET_CODE (x_addr) == VALUE
+ && GET_CODE (mem_addr) != VALUE
+ && reg_mentioned_p (x_addr, mem_addr))
+ || (GET_CODE (x_addr) != VALUE
+ && GET_CODE (mem_addr) == VALUE
+ && reg_mentioned_p (mem_addr, x_addr))))
+ {
+ x_addr = get_addr (x_addr);
+ mem_addr = get_addr (mem_addr);
+ }
if (! writep)
{
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