[Bug target/78102] [5/6/7 regression] GCC refuses to generate PCMPEQQ instruction for SSE4.1

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78102

--- Comment #13 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Actually, now that optabs are looked up using a binary search, the argument
that conv optabs are very expensive doesn't hold any longer, plus we could
arrange for only defining vcond_eq<mode1><mode2> and vec_cmpeq<mode1><mode2> if
corresponding vcond<mode1><mode2>, vcondu<mode1><mode2>, vec_cmp<mode1><mode2>
and vec_cmpu<mode1><mode2> isn't supported; we'd need to pass the comparison
code to the optabs-tree.c predicates, and for EQ_EXPR/NE_EXPR it would just
fall back to the *eq variants.