diff options
| author | rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2010-07-20 12:41:20 +0000 |
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| committer | rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2010-07-20 12:41:20 +0000 |
| commit | ec396ca355d0a4366de7871b0a6806a359dc2bb5 (patch) | |
| tree | 41cab53e4e3521fcb9bc4fa0a65a96ef0019bf99 /gcc/tree-ssa-dom.c | |
| parent | 22d7d92fc9f2516116ea97848745fa2fa0c54d4f (diff) | |
| download | gcc-ec396ca355d0a4366de7871b0a6806a359dc2bb5.tar.gz | |
2010-07-20 Richard Guenther <rguenther@suse.de>
PR tree-optimization/44977
* tree-ssa-dom.c (propagate_rhs_into_lhs): Do not create invalid
SSA form.
* gcc.dg/torture/pr44977.c: New testcase.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@162334 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/tree-ssa-dom.c')
| -rw-r--r-- | gcc/tree-ssa-dom.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/gcc/tree-ssa-dom.c b/gcc/tree-ssa-dom.c index 68338206a8a..4715592746c 100644 --- a/gcc/tree-ssa-dom.c +++ b/gcc/tree-ssa-dom.c @@ -2559,6 +2559,20 @@ propagate_rhs_into_lhs (gimple stmt, tree lhs, tree rhs, bitmap interesting_name continue; } + /* It's not ok to propagate into the definition stmt of RHS. + <bb 9>: + # prephitmp.12_36 = PHI <g_67.1_6(9)> + g_67.1_6 = prephitmp.12_36; + goto <bb 9>; + While this is strictly all dead code we do not want to + deal with this here. */ + if (TREE_CODE (rhs) == SSA_NAME + && SSA_NAME_DEF_STMT (rhs) == use_stmt) + { + all = false; + continue; + } + /* Dump details. */ if (dump_file && (dump_flags & TDF_DETAILS)) { |