https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65546
--- Comment #5 from Bill Schmidt <wschmidt at gcc dot gnu.org> --- For GCC 6, this is just a testcase error. The failing assertion requires this clause now that we can vectorize the loop using misaligned loads/stores: { target { ! vect_hw_misalign } } I'll get that fixed shortly, then see what's up on 4.9 and 5.