https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66675
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Basically VECTOR_CST + VECTOR_CST is not optimized at all. I bet almost all operations that act on VECTOR_CST are not optimized including and not limited to PLUS, SUB, MULTIPLY, DIVIDE, SHIFT, IOR, XOR, and AND.
