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re PR tree-optimization/38747 (Wrong code due to VIEW_CONVERT_EXPR)

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2009-01-20  Andrew Pinski  <andrew_pinski@playstation.sony.com>
	Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/38747
	PR tree-optimization/38748
	* tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Disable the VCE
	conversion if the base address is an indirect reference and the
	aliasing sets could cause issues.

	* gcc.dg/tree-ssa/struct-aliasing-1.c: New test.
	* gcc.dg/tree-ssa/struct-aliasing-2.c: Likewise.
	* gcc.c-torture/execute/struct-aliasing-1.c: Likewise.

Co-Authored-By: Richard Guenther <rguenther@suse.de>

From-SVN: r143523
This commit is contained in:
Andrew Pinski 2009-01-20 17:10:40 +00:00 committed by Richard Biener
parent d0a589040b
commit 37348bf105
6 changed files with 79 additions and 4 deletions
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9
gcc/ChangeLog
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@ -1,3 +1,12 @@
2009-01-20 Andrew Pinski <andrew_pinski@playstation.sony.com>
Richard Guenther <rguenther@suse.de>
PR tree-optimization/38747
PR tree-optimization/38748
* tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Disable the VCE
conversion if the base address is an indirect reference and the
aliasing sets could cause issues.
2009-01-20 Sebastian Pop <sebastian.pop@amd.com>
* common.opt (fgraphite, fgraphite-identity): Add comment for

9
gcc/testsuite/ChangeLog
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@ -1,3 +1,12 @@
2009-01-20 Andrew Pinski <andrew_pinski@playstation.sony.com>
Richard Guenther <rguenther@suse.de>
PR tree-optimization/38747
PR tree-optimization/38748
* gcc.dg/tree-ssa/struct-aliasing-1.c: New test.
* gcc.dg/tree-ssa/struct-aliasing-2.c: Likewise.
* gcc.c-torture/execute/struct-aliasing-1.c: Likewise.
2009-01-20 Kees Cook <kees@ubuntu.com>
H.J. Lu <hongjiu.lu@intel.com>

17
gcc/testsuite/gcc.c-torture/execute/struct-aliasing-1.c Normal file
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@ -0,0 +1,17 @@
struct S { float f; };
int __attribute__((noinline))
foo (int *r, struct S *p)
{
int *q = (int *)&p->f;
int i = *q;
*r = 0;
return i + *q;
}
extern void abort (void);
int main()
{
int i = 1;
if (foo (&i, (struct S *)&i) != 1)
abort ();
return (0);
}

15
gcc/testsuite/gcc.dg/tree-ssa/struct-aliasing-1.c Normal file
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@ -0,0 +1,15 @@
/* { dg-do "compile" } */
/* { dg-options "-O2 -fdump-tree-fre" } */
struct S { float f; };
int __attribute__((noinline))
foo (float *r, struct S *p)
{
int *q = (int *)&p->f;
int i = *q;
*r = 0.0;
return i + *q;
}
/* { dg-final { scan-tree-dump-times "\\\*q" 1 "fre" } } */
/* { dg-final { cleanup-tree-dump "fre" } } */

18
gcc/testsuite/gcc.dg/tree-ssa/struct-aliasing-2.c Normal file
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@ -0,0 +1,18 @@
/* { dg-do "compile" } */
/* { dg-options "-O2 -fdump-tree-fre" } */
struct S { unsigned f; };
int
foo ( struct S *p)
{
int *q = (int *)&p->f;
int i = *q;
return i + p->f;
}
/* There should only be one load of p->f because fwprop can change *(int *)&p->f into just (int)p->f. */
/* { dg-final { scan-tree-dump-times "p_.\\\(D\\\)->f" 1 "fre" } } */
/* { dg-final { cleanup-tree-dump "fre" } } */

15
gcc/tree-ssa-forwprop.c
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@ -777,7 +777,7 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
&& operand_equal_p (TYPE_SIZE (TREE_TYPE (rhs)),
TYPE_SIZE (TREE_TYPE (TREE_OPERAND (def_rhs, 0))), 0))
{
tree new_rhs = unshare_expr (TREE_OPERAND (def_rhs, 0));
tree def_rhs_base, new_rhs = unshare_expr (TREE_OPERAND (def_rhs, 0));
new_rhs = fold_build1 (VIEW_CONVERT_EXPR, TREE_TYPE (rhs), new_rhs);
if (TREE_CODE (new_rhs) != VIEW_CONVERT_EXPR)
{
@ -788,16 +788,23 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
new_rhs = force_gimple_operand_gsi (use_stmt_gsi, new_rhs, true, NULL,
true, GSI_NEW_STMT);
gimple_assign_set_rhs1 (use_stmt, new_rhs);
tidy_after_forward_propagate_addr (use_stmt);
return true;
}
else
/* If the defining rhs comes from an indirect reference, then do not
convert into a VIEW_CONVERT_EXPR. */
def_rhs_base = TREE_OPERAND (def_rhs, 0);
while (handled_component_p (def_rhs_base))
def_rhs_base = TREE_OPERAND (def_rhs_base, 0);
if (!INDIRECT_REF_P (def_rhs_base))
{
/* We may have arbitrary VIEW_CONVERT_EXPRs in a nested component
reference. Place it there and fold the thing. */
*rhsp = new_rhs;
fold_stmt_inplace (use_stmt);
tidy_after_forward_propagate_addr (use_stmt);
return true;
}
tidy_after_forward_propagate_addr (use_stmt);
return true;
}
/* If the use of the ADDR_EXPR is not a POINTER_PLUS_EXPR, there