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| author | Richard Guenther <rguenther@suse.de> | 2011-04-26 09:21:44 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2011-04-26 09:21:44 +0000 |
| commit | ad0e2567d69760fa7156ef24418b4d10f99def6a (patch) | |
| tree | 8ff4c2719e2c23a082193dd49ef8d3a607ac33e4 /gcc/fold-const.c | |
| parent | 0d467c0bf219265a40b0cfe284092ec5382d4b1a (diff) | |
| download | gcc-ad0e2567d69760fa7156ef24418b4d10f99def6a.zip gcc-ad0e2567d69760fa7156ef24418b4d10f99def6a.tar.gz gcc-ad0e2567d69760fa7156ef24418b4d10f99def6a.tar.bz2 | |
re PR tree-optimization/48694 (possible memory hog bug)
2011-04-26 Richard Guenther <rguenther@suse.de>
PR middle-end/48694
* tree.h (OEP_CONSTANT_ADDRESS_OF): New operand_equal_flag.
* fold-const.c (operand_equal_p): For TREE_CONSTANT ADDR_EXPRs
compare the operands with OEP_CONSTANT_ADDRESS_OF. Treat
trees with TREE_SIDE_EFFECTS equal when OEP_CONSTANT_ADDRESS_OF
is set.
* gcc.dg/torture/pr48694-1.c: New testcase.
* gcc.dg/torture/pr48694-2.c: Likewise.
From-SVN: r172954
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 8f90f6f..1aa0dec 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -2473,9 +2473,12 @@ operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags) equal if they have no side effects. If we have two identical expressions with side effects that should be treated the same due to the only side effects being identical SAVE_EXPR's, that will - be detected in the recursive calls below. */ + be detected in the recursive calls below. + If we are taking an invariant address of two identical objects + they are necessarily equal as well. */ if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST) && (TREE_CODE (arg0) == SAVE_EXPR + || (flags & OEP_CONSTANT_ADDRESS_OF) || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1)))) return 1; @@ -2538,7 +2541,8 @@ operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags) case ADDR_EXPR: return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), - 0); + TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1) + ? OEP_CONSTANT_ADDRESS_OF : 0); default: break; } |