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| author | Richard Biener <rguenther@suse.de> | 2013-08-29 13:04:19 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2013-08-29 13:04:19 +0000 |
| commit | 301bbc16628d9ca57cd7b0af306fde6753f04911 (patch) | |
| tree | 0a21cee48f6a9e573e775c87ff8e1a9a4c321ae4 /gcc/tree-ssa-dce.c | |
| parent | 4860a46271bd50674a3adf1bc33704b98d7efffc (diff) | |
| download | gcc-301bbc16628d9ca57cd7b0af306fde6753f04911.zip gcc-301bbc16628d9ca57cd7b0af306fde6753f04911.tar.gz gcc-301bbc16628d9ca57cd7b0af306fde6753f04911.tar.bz2 | |
re PR tree-optimization/58246 (wrong code at -O1 and above)
2013-08-29 Richard Biener <rguenther@suse.de>
PR tree-optimization/58246
* tree-ssa-dce.c (mark_aliased_reaching_defs_necessary_1): Properly
handle the dominance check inside a basic-block.
* gcc.dg/torture/pr58246.c: New testcase.
From-SVN: r202071
Diffstat (limited to 'gcc/tree-ssa-dce.c')
| -rw-r--r-- | gcc/tree-ssa-dce.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c index 4fd3cd8..22ae50b 100644 --- a/gcc/tree-ssa-dce.c +++ b/gcc/tree-ssa-dce.c @@ -574,6 +574,11 @@ mark_aliased_reaching_defs_necessary_1 (ao_ref *ref, tree vdef, void *data) in the references (gcc.c-torture/execute/pr42142.c). The simplest way is to check if the kill dominates the use. */ + /* But when both are in the same block we cannot + easily tell whether we came from a backedge + unless we decide to compute stmt UIDs + (see PR58246). */ + && (basic_block) data != gimple_bb (def_stmt) && dominated_by_p (CDI_DOMINATORS, (basic_block) data, gimple_bb (def_stmt)) && operand_equal_p (ref->ref, lhs, 0)) |