tree-ssa-alias.c (struct used_part): Add write_only field.

2006-01-16  Richard Guenther  <rguenther@suse.de>

	* tree-ssa-alias.c (struct used_part): Add write_only field.
	(get_or_create_used_part_for): Initialize it to true.
	(create_overlap_variables_for): Don't create structure variables
	for structures that only are written to.
	(find_used_portions): Handle MODIFY_EXPR to track whether a
	structure is only written to.

	* gcc.dg/tree-ssa/20031015-1.c: Adjust testcase.

From-SVN: r109766
This commit is contained in:
Richard Guenther 2006-01-16 19:35:08 +00:00 committed by Richard Biener
parent dcc2da4198
commit 183596ebac
4 changed files with 29 additions and 7 deletions

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@ -1,3 +1,12 @@
2006-01-16 Richard Guenther <rguenther@suse.de>
* tree-ssa-alias.c (struct used_part): Add write_only field.
(get_or_create_used_part_for): Initialize it to true.
(create_overlap_variables_for): Don't create structure variables
for structures that only are written to.
(find_used_portions): Handle MODIFY_EXPR to track whether a
structure is only written to.
2006-01-16 Kazu Hirata <kazu@codesourcery.com>
* bb-reorder.c (partition_hot_cold_basic_blocks): Make it

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@ -1,3 +1,7 @@
2006-01-16 Richard Guenther <rguenther@suse.de>
* gcc.dg/tree-ssa/20031015-1.c: Adjust testcase.
2006-01-16 John David Anglin <dave.anglin@nrc-cnrc.gc.ca>
PR testsuite/25777

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@ -13,8 +13,6 @@ main(void)
return 0;
}
/* The V_MUST_DEF comes from the initial assignment; the V_MAY_DEF
comes from the asm. */
/* { dg-final { scan-tree-dump-times "V_MUST_DEF" 1 "alias1" } } */
/* { dg-final { scan-tree-dump-times "V_MAY_DEF" 1 "alias1" } } */
/* The V_*_DEF comes from the initial assignment and the asm. */
/* { dg-final { scan-tree-dump-times "_DEF" 2 "alias1" } } */
/* { dg-final { cleanup-tree-dump "alias1" } } */

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@ -2424,6 +2424,8 @@ typedef struct used_part
variable. Implicit uses occur when we can't tell what part we
are referencing, and have to make conservative assumptions. */
bool implicit_uses;
/* True if the structure is only written to or taken its address. */
bool write_only;
} *used_part_t;
/* An array of used_part structures, indexed by variable uid. */
@ -2509,6 +2511,7 @@ get_or_create_used_part_for (size_t uid)
up->maxused = 0;
up->explicit_uses = false;
up->implicit_uses = false;
up->write_only = true;
}
return up;
@ -2552,10 +2555,11 @@ create_overlap_variables_for (tree var)
used_part_t up;
size_t uid = DECL_UID (var);
if (!up_lookup (uid))
up = up_lookup (uid);
if (!up
|| up->write_only)
return;
up = up_lookup (uid);
push_fields_onto_fieldstack (TREE_TYPE (var), &fieldstack, 0, NULL);
if (VEC_length (fieldoff_s, fieldstack) != 0)
{
@ -2691,10 +2695,15 @@ create_overlap_variables_for (tree var)
entire structure. */
static tree
find_used_portions (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
find_used_portions (tree *tp, int *walk_subtrees, void *lhs_p)
{
switch (TREE_CODE (*tp))
{
case MODIFY_EXPR:
/* Recurse manually here to track whether the use is in the
LHS of an assignment. */
find_used_portions (&TREE_OPERAND (*tp, 0), walk_subtrees, tp);
return find_used_portions (&TREE_OPERAND (*tp, 1), walk_subtrees, NULL);
case REALPART_EXPR:
case IMAGPART_EXPR:
case COMPONENT_REF:
@ -2723,6 +2732,8 @@ find_used_portions (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
up->explicit_uses = true;
else
up->implicit_uses = true;
if (!lhs_p)
up->write_only = false;
up_insert (uid, up);
*walk_subtrees = 0;