Hi Chad, +def int_aarch64_neon_vceqz : + Intrinsic<[llvm_v1i64_ty], [llvm_v1i64_ty], [IntrNoMem]>; Isn't this just an int_aarch64_neon_vceq with the second argument a constant 0? Possibly modelled as a NEON_VDUP for selection? Cheers. Tim.