https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122573
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> --- VMAT_INVARIANT needs SLP support and discovery needs to allow them as it would allow external defs. Optionally vect_analyze_data_ref_access might preserve the group status, but then VMAT_INVARIANT would need to support emitting vector loads + permutes.
