diff options
| author | Richard Biener <rguenther@suse.de> | 2020-10-08 13:18:57 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2020-10-08 14:22:28 +0200 |
| commit | 629e0547af33221a925f38757b52a9284148b68a (patch) | |
| tree | 346ef3990a12adf0022f382cb1d920a47f5af6aa /gcc | |
| parent | 2bdf324fb33d67f0850139040df0c0390258ab38 (diff) | |
| download | gcc-629e0547af33221a925f38757b52a9284148b68a.zip gcc-629e0547af33221a925f38757b52a9284148b68a.tar.gz gcc-629e0547af33221a925f38757b52a9284148b68a.tar.bz2 | |
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')
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr97330-1.c | 19 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr97330-2.c | 14 | ||||
| -rw-r--r-- | gcc/tree-ssa-sink.c | 4 |
3 files changed, 36 insertions, 1 deletions
diff --git a/gcc/testsuite/gcc.dg/torture/pr97330-1.c b/gcc/testsuite/gcc.dg/torture/pr97330-1.c new file mode 100644 index 0000000..7dce5bd --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr97330-1.c @@ -0,0 +1,19 @@ +/* { dg-do compile } */ + +typedef int a; +typedef char b; +int c; +void d(e, f, dst, g, avail, h) int e; +b *f, *dst; +a g, avail; +int h; +{ + b i = *f; + if (e) + goto j; + while (avail) { + *dst = i; + j: + avail -= c; + } +} diff --git a/gcc/testsuite/gcc.dg/torture/pr97330-2.c b/gcc/testsuite/gcc.dg/torture/pr97330-2.c new file mode 100644 index 0000000..a064483 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr97330-2.c @@ -0,0 +1,14 @@ +/* { dg-do compile } */ + +int a, b, d; +char c, e; +void f(void) { + char g = c; + if (b) + goto h; + while (d) { + e = c; + h: + d -= a; + } +} 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; |