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re PR middle-end/30636 (incorrect array bounds warning on multi-dimensional arrays) 

2007-02-04  Richard Guenther  <rguenther@suse.de>

	PR middle-end/30636
	* fold-const.c (try_move_mult_to_index): Make sure to not
	overflow one dimension of a multi-dimensional array access.

	* g++.dg/warn/pr30636.C: New testcase.
	* g++.dg/tree-ssa/tmmti-2.C: XFAIL parts.

From-SVN: r121575
This commit is contained in:
Richard Guenther 2007-02-04 15:15:38 +00:00 committed by Richard Biener
parent 5c4f0f4793
commit 713e3ec92f
5 changed files with 59 additions and 1 deletions
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6
gcc/ChangeLog
View File

@ -1,3 +1,9 @@
2007-02-04 Richard Guenther <rguenther@suse.de>
PR middle-end/30636
* fold-const.c (try_move_mult_to_index): Make sure to not
overflow one dimension of a multi-dimensional array access.
2007-02-04 Jan Hubicka <jh@suse.cz>
* passes.c (init_optimization_passes): Reindent.

29
gcc/fold-const.c
View File

@ -6642,6 +6642,7 @@ try_move_mult_to_index (enum tree_code code, tree addr, tree op1)
tree ref = TREE_OPERAND (addr, 0), pref;
tree ret, pos;
tree itype;
bool mdim = false;
/* Canonicalize op1 into a possibly non-constant delta
and an INTEGER_CST s. */
@ -6681,6 +6682,10 @@ try_move_mult_to_index (enum tree_code code, tree addr, tree op1)
{
if (TREE_CODE (ref) == ARRAY_REF)
{
/* Remember if this was a multi-dimensional array. */
if (TREE_CODE (TREE_OPERAND (ref, 0)) == ARRAY_REF)
mdim = true;
itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
if (! itype)
continue;
@ -6703,8 +6708,32 @@ try_move_mult_to_index (enum tree_code code, tree addr, tree op1)
delta = tmp;
}
/* Only fold here if we can verify we do not overflow one
dimension of a multi-dimensional array. */
if (mdim)
{
tree tmp;
if (TREE_CODE (TREE_OPERAND (ref, 1)) != INTEGER_CST
|| !INTEGRAL_TYPE_P (itype)
|| !TYPE_MAX_VALUE (itype)
|| TREE_CODE (TYPE_MAX_VALUE (itype)) != INTEGER_CST)
continue;
tmp = fold_binary (code, itype,
fold_convert (itype,
TREE_OPERAND (ref, 1)),
fold_convert (itype, delta));
if (!tmp
|| TREE_CODE (tmp) != INTEGER_CST
|| tree_int_cst_lt (TYPE_MAX_VALUE (itype), tmp))
continue;
}
break;
}
else
mdim = false;
if (!handled_component_p (ref))
return NULL_TREE;

6
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,9 @@
2007-02-04 Richard Guenther <rguenther@suse.de>
PR middle-end/30636
* g++.dg/warn/pr30636.C: New testcase.
* g++.dg/tree-ssa/tmmti-2.C: XFAIL parts.
2007-02-03 Uros Bizjak <ubizjak@gmail.com>
PR middle-end/30667

2
gcc/testsuite/g++.dg/tree-ssa/tmmti-2.C
View File

@ -17,6 +17,6 @@ double bar(int i)
return *(&b[0].x + i*2); // b[i].x
}
/* { dg-final { scan-tree-dump "a\\\[.*i.*\\\]\\\[0\\\]" "optimized" } } */
/* { dg-final { scan-tree-dump "a\\\[.*i.*\\\]\\\[0\\\]" "optimized" { xfail *-*-* } } } */
/* { dg-final { scan-tree-dump "b\\\[.*i.*\\\].x" "optimized" } } */
/* { dg-final { cleanup-tree-dump "optimized" } } */

17
gcc/testsuite/g++.dg/warn/pr30636.C Normal file
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@ -0,0 +1,17 @@
/* { dg-do compile } */
/* { dg-options "-O2 -Warray-bounds" } */
typedef char one_buffer[512];
static one_buffer emergency_buffer[4];
void free_exception (void *vptr)
{
char *base = (char *) &emergency_buffer[0][0];
char *ptr = (char *) vptr;
if (ptr >= base && ptr < base + sizeof (emergency_buffer)) /* { dg-bogus "subscript" } */
{
/* Do something. */
__builtin_exit (0);
}
}