(ADD(Q|L)const [c] (LEA(Q|L)1 [d] {s} x y)) && is32Bit(int64(c)+int64(d)) => (LEA(Q|L)1 [c+d] {s} x y)
(ADD(Q|L)const [c] (LEA(Q|L)2 [d] {s} x y)) && is32Bit(int64(c)+int64(d)) => (LEA(Q|L)2 [c+d] {s} x y)
(ADD(Q|L)const [c] (LEA(Q|L)4 [d] {s} x y)) && is32Bit(int64(c)+int64(d)) => (LEA(Q|L)4 [c+d] {s} x y)
(ADD(Q|L)const [c] (LEA(Q|L)8 [d] {s} x y)) && is32Bit(int64(c)+int64(d)) => (LEA(Q|L)8 [c+d] {s} x y)

(CGRJ  {c} x (MOVDconst [y]) yes no) && !is8Bit(y)  && is32Bit(y)  => (BRC {c} (CMPconst   x [int32(y)]) yes no)
(CRJ   {c} x (MOVDconst [y]) yes no) && !is8Bit(y)  && is32Bit(y)  => (BRC {c} (CMPWconst  x [int32(y)]) yes no)
(CLGRJ {c} x (MOVDconst [y]) yes no) && !isU8Bit(y) && isU32Bit(y) => (BRC {c} (CMPUconst  x [int32(y)]) yes no)
(CLRJ  {c} x (MOVDconst [y]) yes no) && !isU8Bit(y) && isU32Bit(y) => (BRC {c} (CMPWUconst x [int32(y)]) yes no)

// Arithmetic constant ops

(ADD x (MOVDconst <t> [c])) && is32Bit(c) && !t.IsPtr() => (ADDconst [c] x)
(ADDconst [c] (ADDconst [d] x)) && is32Bit(c+d) => (ADDconst [c+d] x)
(ADDconst [0] x) => x
(SUB x (MOVDconst [c])) && is32Bit(-c) => (ADDconst [-c] x)

(ADDconst [c] (MOVDaddr [d] {sym} x)) && is32Bit(c+int64(d)) => (MOVDaddr [int32(c+int64(d))] {sym} x)
(ADDconst [c] x:(SP)) && is32Bit(c) => (MOVDaddr [int32(c)] x) // so it is rematerializeable

// isUint32PowerOfTwo reports whether uint32(n) is a power of 2.
func isUint32PowerOfTwo(in int64) bool {
	n := uint64(uint32(in))
	return n > 0 && n&(n-1) == 0
}

// is32Bit reports whether n can be represented as a signed 32 bit integer.
func is32Bit(n int64) bool {
	return n == int64(int32(n))
}

// is16Bit reports whether n can be represented as a signed 16 bit integer.
func is16Bit(n int64) bool {

	rd := x & (1<<5 - 1)
	is_32bit := !has_width
	var rea RegExtshiftAmount
	if has_width {
		if option&0x3 != 0x3 {
			rea.reg = W0 + Reg(rm)
		} else {
			rea.reg = X0 + Reg(rm)
		}
	} else {
		rea.reg = W0 + Reg(rm)
	}
	switch option {
	case 0:
		rea.extShift = uxtb
	case 1:
		rea.extShift = uxth
	case 2:
		if is_32bit && (rn == 31 || (s == 0 && rd == 31)) {