[Bug tree-optimization/66675] Could improve vector lane folding style operations.

[pinskia at gcc dot gnu.org]

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.