https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80846
--- Comment #14 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Richard Biener from comment #11) > that's not using the unpacking strategy (sum adjacent elements) but still the > vector shift approach (add upper/lower halves). That's sth that can be > changed independently. > > Waiting for final vec_extract/init2 optab settling. That should be settled now. BTW, for reductions in PR80324 I've added for avx512fintrin.h __MM512_REDUCE_OP which for reductions from 512-bit vectors uses smaller and smaller vectors, perhaps that is something we should use for the reductions emitted by the vectorizer too (perhaps through a target hook that would emit gimple for the reduction)?
