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| author | Richard Biener <rguenther@suse.de> | 2023-01-30 09:25:23 +0100 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2023-01-30 10:50:52 +0100 |
| commit | 7ac3e69e311351b70407d7f87a0169c4d463e57b (patch) | |
| tree | 3435a90ad55baa9432ac21daaa9f636b25629661 /gcc/tree-ssa-phiopt.cc | |
| parent | 3cd08f7168c196d7a481b9ed9f4289fd1f14eea8 (diff) | |
| download | gcc-7ac3e69e311351b70407d7f87a0169c4d463e57b.zip gcc-7ac3e69e311351b70407d7f87a0169c4d463e57b.tar.gz gcc-7ac3e69e311351b70407d7f87a0169c4d463e57b.tar.bz2 | |
tree-optimization/108574 - wrong-code with PRE PHI node processing
The PR108523 was too optimistic in replacing the same value with
an equivalence from a possibly not taken edge. The following
rectifies this and instead refrains from using the equivalence in
the problematic cases.
PR tree-optimization/108574
* tree-ssa-sccvn.cc (visit_phi): Instead of swapping
sameval and def, ignore the equivalence if there's the
danger of oscillating between two values.
* gcc.dg/torture/pr108574-1.c: New testcase.
* gcc.dg/torture/pr108574-2.c: Likewise.
* gcc.dg/torture/pr108574-3.c: Likewise.
Diffstat (limited to 'gcc/tree-ssa-phiopt.cc')
0 files changed, 0 insertions, 0 deletions