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authorRichard Biener <rguenther@suse.de>2020-10-08 13:18:57 +0200
committerRichard Biener <rguenther@suse.de>2020-10-08 14:22:28 +0200
commit629e0547af33221a925f38757b52a9284148b68a (patch)
tree346ef3990a12adf0022f382cb1d920a47f5af6aa /gcc/tree-ssa-sink.c
parent2bdf324fb33d67f0850139040df0c0390258ab38 (diff)
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tree-optimization/97330 - fix bad load sinking
This fixes bad placement of sunk loads. 2020-10-08 Richard Biener <rguenther@suse.de> PR tree-optimization/97330 * tree-ssa-sink.c (statement_sink_location): Avoid skipping PHIs when they dominate the insert location. * gcc.dg/torture/pr97330-1.c: New testcase. * gcc.dg/torture/pr97330-2.c: Likewise.
Diffstat (limited to 'gcc/tree-ssa-sink.c')
-rw-r--r--gcc/tree-ssa-sink.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/gcc/tree-ssa-sink.c b/gcc/tree-ssa-sink.c
index ba8e557..207aae2 100644
--- a/gcc/tree-ssa-sink.c
+++ b/gcc/tree-ssa-sink.c
@@ -391,8 +391,10 @@ statement_sink_location (gimple *stmt, basic_block frombb,
if (gimple_code (use_stmt) == GIMPLE_PHI)
{
/* In case the PHI node post-dominates the current insert location
- we can disregard it. */
+ we can disregard it. But make sure it is not dominating
+ it as well as can happen in a CFG cycle. */
if (commondom != bb
+ && !dominated_by_p (CDI_DOMINATORS, commondom, bb)
&& dominated_by_p (CDI_POST_DOMINATORS, commondom, bb))
continue;
bb = EDGE_PRED (bb, PHI_ARG_INDEX_FROM_USE (use_p))->src;