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Fix tail-merge pass for dead type-unsafe code

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2014-11-19  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/62167
	* tree-ssa-tail-merge.c (stmt_local_def): Handle statements with vuse
	conservatively.
	(gimple_equal_p): Don't use vn_valueize to compare for lhs equality of
	assigns.

	* gcc.dg/pr51879-12.c: Add xfails.
	* gcc.dg/pr62167-run.c: New test.
	* gcc.dg/pr62167.c: New test.

From-SVN: r217761
This commit is contained in:
Tom de Vries 2014-11-19 10:44:58 +00:00 • committed by Tom de Vries
parent 4a19f719d6
commit 8024d4b6c9
6 changed files with 118 additions and 4 deletions
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8
gcc/ChangeLog
View file

@ -1,3 +1,11 @@
2014-11-19 Tom de Vries <tom@codesourcery.com>
PR tree-optimization/62167
* tree-ssa-tail-merge.c (stmt_local_def): Handle statements with vuse
conservatively.
(gimple_equal_p): Don't use vn_valueize to compare for lhs equality of
assigns.
2014-11-19 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/63915

7
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,10 @@
2014-11-19 Tom de Vries <tom@codesourcery.com>
PR tree-optimization/62167
* gcc.dg/pr51879-12.c: Add xfails.
* gcc.dg/pr62167-run.c: New test.
* gcc.dg/pr62167.c: New test.
2014-11-19 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/63915

4
gcc/testsuite/gcc.dg/pr51879-12.c
View file

@ -24,6 +24,6 @@ foo (int y)
baz (a);
}
/* { dg-final { scan-tree-dump-times "bar \\(" 1 "pre"} } */
/* { dg-final { scan-tree-dump-times "bar2 \\(" 1 "pre"} } */
/* { dg-final { scan-tree-dump-times "bar \\(" 1 "pre" { xfail *-*-* } } } */
/* { dg-final { scan-tree-dump-times "bar2 \\(" 1 "pre" { xfail *-*-* } } } */
/* { dg-final { cleanup-tree-dump "pre" } } */

47
gcc/testsuite/gcc.dg/pr62167-run.c Normal file
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@ -0,0 +1,47 @@
/* { dg-do run } */
/* { dg-options "-O2 -ftree-tail-merge" } */
struct node
{
struct node *next;
struct node *prev;
};
struct node node;
struct head
{
struct node *first;
};
struct head heads[5];
int k = 2;
struct head *head = &heads[2];
int
main ()
{
struct node *p;
node.next = (void*)0;
node.prev = (void *)head;
head->first = &node;
struct node *n = head->first;
struct head *h = &heads[k];
heads[2].first = n->next;
if ((void*)n->prev == (void *)h)
p = h->first;
else
/* Dead tbaa-unsafe load from ((struct node *)&heads[2])->next. */
p = n->prev->next;
return !(p == (void*)0);
}

50
gcc/testsuite/gcc.dg/pr62167.c Normal file
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@ -0,0 +1,50 @@
/* { dg-do compile } */
/* { dg-options "-O2 -ftree-tail-merge -fdump-tree-pre" } */
struct node
{
struct node *next;
struct node *prev;
};
struct node node;
struct head
{
struct node *first;
};
struct head heads[5];
int k = 2;
struct head *head = &heads[2];
int
main ()
{
struct node *p;
node.next = (void*)0;
node.prev = (void *)head;
head->first = &node;
struct node *n = head->first;
struct head *h = &heads[k];
heads[2].first = n->next;
if ((void*)n->prev == (void *)h)
p = h->first;
else
/* Dead tbaa-unsafe load from ((struct node *)&heads[2])->next. */
p = n->prev->next;
return !(p == (void*)0);
}
/* { dg-final { scan-tree-dump-not "Removing basic block" "pre"} } */
/* { dg-final { cleanup-tree-dump "pre" } } */

6
gcc/tree-ssa-tail-merge.c
View file

@ -326,7 +326,8 @@ stmt_local_def (gimple stmt)
if (gimple_vdef (stmt) != NULL_TREE
|| gimple_has_side_effects (stmt)
|| gimple_could_trap_p_1 (stmt, false, false))
|| gimple_could_trap_p_1 (stmt, false, false)
|| gimple_vuse (stmt) != NULL_TREE)
return false;
def_p = SINGLE_SSA_DEF_OPERAND (stmt, SSA_OP_DEF);
@ -1175,7 +1176,8 @@ gimple_equal_p (same_succ same_succ, gimple s1, gimple s2)
gimple_assign_rhs1 (s2)));
else if (TREE_CODE (lhs1) == SSA_NAME
&& TREE_CODE (lhs2) == SSA_NAME)
return vn_valueize (lhs1) == vn_valueize (lhs2);
return operand_equal_p (gimple_assign_rhs1 (s1),
gimple_assign_rhs1 (s2), 0);
return false;
case GIMPLE_COND: