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| author | Richard Biener <rguenther@suse.de> | 2016-01-29 11:21:19 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2016-01-29 11:21:19 +0000 |
| commit | d4abfcc561b77aa2ac7328d965b08efd1b2561b2 (patch) | |
| tree | d41c277b595780348ce12b51329c77c3442d46d6 /gcc/tree-ssa-dce.c | |
| parent | 16b77b321eb72c5e2e1ec3628c035df80bef8534 (diff) | |
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re PR middle-end/69547 (no-op array initializer emits an empty loop)
2016-01-29 Richard Biener <rguenther@suse.de>
PR tree-optimization/69547
* tree-ssa-dce.c (mark_aliased_reaching_defs_necessary_1):
Do not mark clobbers necessary.
(mark_all_reaching_defs_necessary_1): Likewise.
* g++.dg/tree-ssa/pr69547.C: New testcase.
From-SVN: r232976
Diffstat (limited to 'gcc/tree-ssa-dce.c')
| -rw-r--r-- | gcc/tree-ssa-dce.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/gcc/tree-ssa-dce.c b/gcc/tree-ssa-dce.c index 8c3dd8f..75aaee9 100644 --- a/gcc/tree-ssa-dce.c +++ b/gcc/tree-ssa-dce.c @@ -462,7 +462,8 @@ mark_aliased_reaching_defs_necessary_1 (ao_ref *ref, tree vdef, void *data) gimple *def_stmt = SSA_NAME_DEF_STMT (vdef); /* All stmts we visit are necessary. */ - mark_operand_necessary (vdef); + if (! gimple_clobber_p (def_stmt)) + mark_operand_necessary (vdef); /* If the stmt lhs kills ref, then we can stop walking. */ if (gimple_has_lhs (def_stmt) @@ -584,7 +585,8 @@ mark_all_reaching_defs_necessary_1 (ao_ref *ref ATTRIBUTE_UNUSED, } } - mark_operand_necessary (vdef); + if (! gimple_clobber_p (def_stmt)) + mark_operand_necessary (vdef); return false; } |