https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65494
--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> --- vect_build_slp_tree apparently has code to handle (limited number) of permutations for commutative operands, but even if I bump the && *npermutes < 4 test to && *npermutes < 32, for some reason we still don't handle it (but only retry 7 times, so don't run into this increased limit).
