https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113734
--- Comment #10 from Tamar Christina <tnfchris at gcc dot gnu.org> --- (In reply to Richard Biener from comment #9) > Another bug in the dependence checking code is > > if (dr_may_alias_p (dr_ref, dr_read, loop_nest)) > > which will end up using TBAA - dr_may_alias_p doesn't think you are ever > going to move stores down across loads. To verify if that's possible > you need to use > > if (dr_may_alias_p (dr_read, dr_ref, loop_nest)) > > instead. > > Note there's still my very original review consideration that you move > stmts out-of-order but the main dependence checking the vectorizer does > assumes the stores and loads appear in their original order. I'm not > sure whether with the above we prove this doesn't matter. But in the original review I had it that way and you said: > + for (auto dr_read : bases) > + if (dr_may_alias_p (dr_read, dr_ref, loop_nest)) I think you need to swap dr_read and dr_ref operands, since you are walking stmts backwards and thus all reads from 'bases' are after the write. so I'm somewhat confused..
