diff options
| author | rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2015-07-23 07:23:23 +0000 |
|---|---|---|
| committer | rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2015-07-23 07:23:23 +0000 |
| commit | 930490667fefb728837333448730d9a889249bd0 (patch) | |
| tree | 0b53234d12f8b5bc5dfcbdc0f99a0ae83f98d561 /gcc/tree-ssa-propagate.c | |
| parent | 43f467b0bb347fcc59d71799f86de53e6933e78e (diff) | |
| download | gcc-930490667fefb728837333448730d9a889249bd0.tar.gz | |
2015-07-23 Richard Biener <rguenther@suse.de>
PR tree-optimization/66945
* tree-ssa-propagate.c (substitute_and_fold_dom_walker
::before_dom_children): Force the propagators idea of
non-executable edges to materialize, not what the folder
chooses.
* gcc.dg/torture/pr66945.c: New testcase.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@226088 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/tree-ssa-propagate.c')
| -rw-r--r-- | gcc/tree-ssa-propagate.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/gcc/tree-ssa-propagate.c b/gcc/tree-ssa-propagate.c index 3f3a694702e..b7684e07905 100644 --- a/gcc/tree-ssa-propagate.c +++ b/gcc/tree-ssa-propagate.c @@ -1236,13 +1236,33 @@ substitute_and_fold_dom_walker::before_dom_children (basic_block bb) /* If we made a replacement, fold the statement. */ if (did_replace) - fold_stmt (&i, follow_single_use_edges); + { + fold_stmt (&i, follow_single_use_edges); + stmt = gsi_stmt (i); + } + + /* If this is a control statement the propagator left edges + unexecuted on force the condition in a way consistent with + that. See PR66945 for cases where the propagator can end + up with a different idea of a taken edge than folding + (once undefined behavior is involved). */ + if (gimple_code (stmt) == GIMPLE_COND) + { + if ((EDGE_SUCC (bb, 0)->flags & EDGE_EXECUTABLE) + ^ (EDGE_SUCC (bb, 1)->flags & EDGE_EXECUTABLE)) + { + if (((EDGE_SUCC (bb, 0)->flags & EDGE_TRUE_VALUE) != 0) + == ((EDGE_SUCC (bb, 0)->flags & EDGE_EXECUTABLE) != 0)) + gimple_cond_make_true (as_a <gcond *> (stmt)); + else + gimple_cond_make_false (as_a <gcond *> (stmt)); + did_replace = true; + } + } /* Now cleanup. */ if (did_replace) { - stmt = gsi_stmt (i); - /* If we cleaned up EH information from the statement, remove EH edges. */ if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt)) |