https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68552
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Created attachment 36847 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36847&action=edit gcc6-pr68552.patch Untested fix. The issue was that the VEC_PERM expansion through vec_shr optab was misplaced, thus it was done only when vec_perm*optab were non-zero for the particular mode, and Alpha has no permutations, just the whole vector shifts.
