https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97521
--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Well, I think it is certainly desirable to keep using VEC_MERGE, not only because it is less IL. But pedantically already what i386 backend does doesn't match the documentation which says that the last operand of VEC_MERGE is a CONST_INT. We could just say that it is either a CONST_INT, or an RTL expression with a scalar integral mode, or V*BImode mode. And another question is how to represent the V*BImode constants, whether to represent them as normal VOIDmode CONST_INTs, or something else (const_vector:V*BI ...).
