https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91166
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> --- Awww. tree fold_vec_perm (tree type, tree arg0, tree arg1, const vec_perm_indices &sel) { unsigned int i; unsigned HOST_WIDE_INT nelts; bool need_ctor = false; if (!sel.length ().is_constant (&nelts)) return NULL_TREE; ;)