https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115355
--- Comment #11 from Kewen Lin <linkw at gcc dot gnu.org> --- (In reply to Jens Seifert from comment #10) > Does this affect loop vectorize and slp vectorize ? > > -fno-tree-loop-vectorize avoids loop vectorization to be performed and > workarounds this issue. Does the same problems also affect SLP > vectorization, which does not take place in this sample. > > In other words, do I need > -fno-tree-loop-vectorize > or > -fno-tree-vectorize > to workaround this bug ? Since it's an issue on vector merge insn patterns in target code and vectorization just exposes it, it's hard to workaround this bug completely just by disabling both loop and slp vectorization, as its related bug PR106069 shows, even without vectorization but using some vec merge built-ins, it's still possible to hit this issue. But I'd expect disabling both loop and slp vectorization (-fno-tree-vectorize) can greatly reduce the possibility of encountering it.
