https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108008
Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Priority|P3 |P2 CC| |rguenth at gcc dot gnu.org See Also| |https://gcc.gnu.org/bugzill | |a/show_bug.cgi?id=107323 Known to work| |13.0 Keywords| |needs-bisection --- Comment #13 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to Alexander Monakov from comment #9) > I think this is tree-ldist placing memset(sameZ, 0, zPlaneCount) after the > loop, overwriting conditional 'sameZ[i] = true' assignments that happen in > the loop. > > For the smaller testcase from comment #6, -O2 -ftree-loop-distribution is > enough, namely: > > works: > > gcc-12 -O2 -ftree-loop-distribution -fno-tree-vectorize > -fno-tree-loop-distribute-patterns > > breaks: > > gcc-12 -O2 -ftree-loop-distribution -fno-tree-vectorize Note I can not reproduce on the branch after r12-8855-g19a9b5e587e87f52, so maybe that's truly the duplicate. Bisecting on the branch might reveal that.