// Convert simple bit masks to an equivalent rldic[lr] if possible.
(AND x:(MOVDconst [m]) n) && isPPC64ValidShiftMask(m) => (RLDICL [encodePPC64RotateMask(0,m,64)] n)
(AND x:(MOVDconst [m]) n) && m != 0 && isPPC64ValidShiftMask(^m) => (RLDICR [encodePPC64RotateMask(0,m,64)] n)

// If the RLDICL does not rotate its value, a shifted value can be merged.
(RLDICL [em] x:(SRDconst [s] a)) && (em&0xFF0000) == 0 => (RLDICL [mergePPC64RLDICLandSRDconst(em, s)] a)

	// ppc64x: "RLDICR\t[$]0, R[0-9]*, [$]47, R"
	io64[0] = io64[0] & 0xFFFFFFFFFFFF0000
	// ppc64x: "RLDICL\t[$]0, R[0-9]*, [$]16, R"
	io64[1] = io64[1] & 0x0000FFFFFFFFFFFF
	// ppc64x: -"SRD", -"AND", "RLDICL\t[$]60, R[0-9]*, [$]16, R"
	io64[2] = (io64[2] >> 4) & 0x0000FFFFFFFFFFFF
	// ppc64x: -"SRD", -"AND", "RLDICL\t[$]36, R[0-9]*, [$]28, R"
	io64[3] = (io64[3] >> 28) & 0x0000FFFFFFFFFFFF