https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99593
--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Before r11-6708 it was using different patterns - ashl<mode>3_signed - and those don't accept immediate CONST_VECTOR at all, while mve_vshlq_<supf><mode> does.
