https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63341
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- Btw, should be reproducible with negative step cases on x86_64 as well, as we do there if (negative) offset = size_int (-TYPE_VECTOR_SUBPARTS (vectype) + 1); ? I suppose interpreting offset in terms of scalar element size is what was intended.