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| author | Richard Biener <rguenther@suse.de> | 2017-09-15 09:19:36 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2017-09-15 09:19:36 +0000 |
| commit | 897da3034cc2b1e3675d891e833c6b2a02fd4fe5 (patch) | |
| tree | d30a6dd766b27849dc68b70824bcd0b2d0b7534f /gcc/tree-ssa-sccvn.c | |
| parent | 854dde43ae85c54a12430a656d01a0db9637b139 (diff) | |
| download | gcc-897da3034cc2b1e3675d891e833c6b2a02fd4fe5.zip gcc-897da3034cc2b1e3675d891e833c6b2a02fd4fe5.tar.gz gcc-897da3034cc2b1e3675d891e833c6b2a02fd4fe5.tar.bz2 | |
re PR tree-optimization/82217 (ICE on valid code at -O1 and above: in visit_phi, at tree-ssa-sccvn.c:3908)
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.
From-SVN: r252796
Diffstat (limited to 'gcc/tree-ssa-sccvn.c')
| -rw-r--r-- | gcc/tree-ssa-sccvn.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c index 44618da..0b0c510 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))) |