diff options
| author | rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2017-09-15 09:19:36 +0000 |
|---|---|---|
| committer | rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4> | 2017-09-15 09:19:36 +0000 |
| commit | 0340b0d489a469b3d441f83e04ea40262e98ba8e (patch) | |
| tree | d30a6dd766b27849dc68b70824bcd0b2d0b7534f | |
| parent | dca0c3a8b3845de69af0ea2ea559bdea92dc5700 (diff) | |
| download | gcc-0340b0d489a469b3d441f83e04ea40262e98ba8e.tar.gz | |
2017-09-15 Richard Biener <rguenther@suse.de>
PR tree-optimization/82217
* tree-ssa-sccvn.c (visit_phi): Properly handle all VN_TOP
but not undefined case.
* gcc.dg/torture/pr82217.c: New testcase.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@252796 138bc75d-0d04-0410-961f-82ee72b054a4
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr82217.c | 32 | ||||
| -rw-r--r-- | gcc/tree-ssa-sccvn.c | 9 |
4 files changed, 46 insertions, 6 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 4711d4e16c1..65bfc163f5a 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2017-09-15 Richard Biener <rguenther@suse.de> + + PR tree-optimization/82217 + * tree-ssa-sccvn.c (visit_phi): Properly handle all VN_TOP + but not undefined case. + 2017-09-15 Jakub Jelinek <jakub@redhat.com> PR target/82145 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index b47923b3802..cd3f7a96c0d 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-09-15 Richard Biener <rguenther@suse.de> + + PR tree-optimization/82217 + * gcc.dg/torture/pr82217.c: New testcase. + 2017-09-15 Jakub Jelinek <jakub@redhat.com> PR target/82145 diff --git a/gcc/testsuite/gcc.dg/torture/pr82217.c b/gcc/testsuite/gcc.dg/torture/pr82217.c new file mode 100644 index 00000000000..471f474aab3 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr82217.c @@ -0,0 +1,32 @@ +/* { dg-do compile } */ + +int a, b, c; + +void fn1 () +{ + while (1) + { + if (c) + goto L2; + break; + } + if (c) + { +L1: + { + int g[1]; + if (b) + goto L1; + goto L1; +L2: + for (a = 0; a;) + goto L1; + } + } +} + +int main () +{ + fn1 (); + return 0; +} diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c index 44618daedce..0b0c5106d30 100644 --- a/gcc/tree-ssa-sccvn.c +++ b/gcc/tree-ssa-sccvn.c @@ -3901,13 +3901,10 @@ visit_phi (gimple *phi) if only a single edge is exectuable use its value. */ if (n_executable <= 1) result = seen_undef ? seen_undef : sameval; - /* If we saw only undefined values create a new undef SSA name to - avoid false equivalences. */ + /* If we saw only undefined values and VN_TOP use one of the + undefined values. */ else if (sameval == VN_TOP) - { - gcc_assert (seen_undef); - result = seen_undef; - } + result = seen_undef ? seen_undef : sameval; /* First see if it is equivalent to a phi node in this block. We prefer this as it allows IV elimination - see PRs 66502 and 67167. */ else if ((result = vn_phi_lookup (phi))) |