Masked reduction intrinsics are specical cases which don't need to have policy operand. The mask only affects which elements are read. It doesn't effect the destination register. The reduction intrinsics have a dedicated destination operand. If it is undef, we use tail agnostic. If it not undef we use tail undisturbed. Co-Authored-by: Craig Topper <craig.topper@sifive.com> Differential Revision: https://reviews.llvm.org/D117681