https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56766
--- Comment #6 from Uroš Bizjak <ubizjak at gmail dot com> --- (In reply to Richard Biener from comment #3) > We still need to fixup the sse3_addsubv2df3 pattern or fix combine to try > multiple "canonical" forms of vec_merge vs. (vec_select (vec_concat ...)). > Or decide which one is canonical (I'd prefer simply dropping vec_merge - with > AVX512 we've run out of bits for the CONST_INT selector....) Does the attached patch work for you? (Please note, that AVX512 does not implement 512bit ADDSUB insn.)
