(Mod16u x y) => (REMVU (ZeroExt16to64 x) (ZeroExt16to64 y))
(Mod8 x y) => (REMV (SignExt8to64 x) (SignExt8to64 y))
(Mod8u x y) => (REMVU (ZeroExt8to64 x) (ZeroExt8to64 y))

(Select0 <t> (Add64carry x y c)) => (ADDV (ADDV <t> x y) c)
(Select1 <t> (Add64carry x y c)) =>
	(OR (SGTU <t> x s:(ADDV <t> x y)) (SGTU <t> s (ADDV <t> s c)))

(Select0 <t> (Sub64borrow x y c)) => (SUBV (SUBV <t> x y) c)
(Select1 <t> (Sub64borrow x y c)) =>

(Hmul64u ...) => (MULHU ...)
(Hmul32 x y)  => (SRAI [32] (MUL  (SignExt32to64 x) (SignExt32to64 y)))
(Hmul32u x y) => (SRLI [32] (MUL  (ZeroExt32to64 x) (ZeroExt32to64 y)))

(Select0 (Add64carry x y c)) => (ADD (ADD <typ.UInt64> x y) c)
(Select1 (Add64carry x y c)) =>
	(OR (SLTU <typ.UInt64> s:(ADD <typ.UInt64> x y) x) (SLTU <typ.UInt64> (ADD <typ.UInt64> s c) s))

(Select0 (Sub64borrow x y c)) => (SUB (SUB <typ.UInt64> x y) c)

(Const(32|64)F ...) => (FMOV(S|D)const ...)
(ConstNil) => (MOVDconst [0])
(ConstBool [t]) => (MOVDconst [b2i(t)])

// Carrying addition.
(Select0 (Add64carry x y c)) =>            (Select0 <typ.UInt64> (ADDE x y (Select1 <typ.UInt64> (ADDCconst c [-1]))))
(Select1 (Add64carry x y c)) => (ADDZEzero (Select1 <typ.UInt64> (ADDE x y (Select1 <typ.UInt64> (ADDCconst c [-1])))))
// Fold initial carry bit if 0.

(Mod8 x y) => (Select0 (DIVV (SignExt8to64 x) (SignExt8to64 y)))
(Mod8u x y) => (Select0 (DIVVU (ZeroExt8to64 x) (ZeroExt8to64 y)))

(Select0 <t> (Add64carry x y c)) => (ADDV (ADDV <t> x y) c)
(Select1 <t> (Add64carry x y c)) =>
	(OR (SGTU <t> x s:(ADDV <t> x y)) (SGTU <t> s (ADDV <t> s c)))

(Select0 <t> (Sub64borrow x y c)) => (SUBV (SUBV <t> x y) c)
(Select1 <t> (Sub64borrow x y c)) =>

(Bswap64 ...) => (MOVDBR ...)
(Bswap32 ...) => (MOVWBR ...)

// add with carry
(Select0 (Add64carry x y c))
  => (Select0 <typ.UInt64> (ADDE x y (Select1 <types.TypeFlags> (ADDCconst c [-1]))))
(Select1 (Add64carry x y c))
  => (Select0 <typ.UInt64> (ADDE (MOVDconst [0]) (MOVDconst [0]) (Select1 <types.TypeFlags> (ADDE x y (Select1 <types.TypeFlags> (ADDCconst c [-1]))))))

	{name: "Sub32carry", argLength: 2, typ: "(UInt32,Flags)"}, // arg0 - arg1, returns (value, carry)
	{name: "Sub32withcarry", argLength: 3},                    // arg0 - arg1 - arg2, arg2=carry (0 or 1)

	{name: "Add64carry", argLength: 3, commutative: true, typ: "(UInt64,UInt64)"}, // arg0 + arg1 + arg2, arg2 must be 0 or 1. returns (value, value>>64)

(Div(64|32|16)u x y) => (Select0 (DIV(Q|L|W)U x y))
(Div8u x y) => (Select0 (DIVWU (ZeroExt8to16 x) (ZeroExt8to16 y)))
(Div(32|64)F ...) => (DIVS(S|D) ...)

(Select0 (Add64carry x y c)) =>
	(Select0 <typ.UInt64> (ADCQ x y (Select1 <types.TypeFlags> (NEGLflags c))))
(Select1 (Add64carry x y c)) =>
	(NEGQ <typ.UInt64> (SBBQcarrymask <typ.UInt64> (Select1 <types.TypeFlags> (ADCQ x y (Select1 <types.TypeFlags> (NEGLflags c))))))
(Select0 (Sub64borrow x y c)) =>

(UMODW <typ.UInt32> x y) => (MSUBW <typ.UInt32> x y (UDIVW <typ.UInt32> x y))

// 64-bit addition with carry.
(Select0 (Add64carry x y c)) => (Select0 <typ.UInt64> (ADCSflags x y (Select1 <types.TypeFlags> (ADDSconstflags [-1] c))))
(Select1 (Add64carry x y c)) => (ADCzerocarry <typ.UInt64> (Select1 <types.TypeFlags> (ADCSflags x y (Select1 <types.TypeFlags> (ADDSconstflags [-1] c)))))

	for {
		if v_0.Op != OpMul64uover {
			break
		}
		y := v_0.Args[1]
		x := v_0.Args[0]
		v.reset(OpLOONG64MULV)
		v.AddArg2(x, y)
		return true
	}
	// match: (Select0 <t> (Add64carry x y c))
	// result: (ADDV (ADDV <t> x y) c)
	for {
		t := v.Type
		if v_0.Op != OpAdd64carry {
			break
		}
		c := v_0.Args[2]
		x := v_0.Args[0]
		y := v_0.Args[1]

		v.reset(OpSelect1)
		v.Type = typ.UInt64
		v0 := b.NewValue0(v.Pos, OpMIPS64MULVU, types.NewTuple(typ.UInt64, typ.UInt64))
		v0.AddArg2(x, y)
		v.AddArg(v0)
		return true
	}
	// match: (Select0 <t> (Add64carry x y c))
	// result: (ADDV (ADDV <t> x y) c)
	for {
		t := v.Type
		if v_0.Op != OpAdd64carry {
			break
		}
		c := v_0.Args[2]
		x := v_0.Args[0]
		y := v_0.Args[1]