(XOR (MOVDconst [val]) x) && is32Bit(val) => (XORI [val] x)
(ROL  x (MOVDconst [val])) => (RORI  [int64(int8(-val)&63)] x)
(ROLW x (MOVDconst [val])) => (RORIW [int64(int8(-val)&31)] x)
(ROR  x (MOVDconst [val])) => (RORI  [int64(val&63)] x)
(RORW x (MOVDconst [val])) => (RORIW [int64(val&31)] x)
(SLL  x (MOVDconst [val])) => (SLLI [int64(val&63)] x)
(SRL  x (MOVDconst [val])) => (SRLI [int64(val&63)] x)

SuffixLoop:
	for i, a := range inst.Args {
		if a == nil {
			break
		}
		switch a := a.(type) {
		case Reg:
			switch inst.Op {
			case MOVSX, MOVZX:
				continue

			case SHL, SHR, RCL, RCR, ROL, ROR, SAR:
				if i == 1 {
					// shift count does not tell us operand size
					continue
				}

			case CRC32:
				// The source argument does tell us operand size,