https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77822
--- Comment #17 from Segher Boessenkool <segher at gcc dot gnu.org> --- Yes, combine should avoid forming patterns that can never match. It already does that in many cases. Where does it form this one? And yes, the target should not allow patterns it has no instruction for, let alone patterns on which it will crash later ;-)
