(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.
(ADDE x y (Select1 <typ.UInt64> (ADDCconst (MOVDconst [0]) [-1]))) => (ADDC x y)

	// result: (MOVVconst [0])
	for {
		if v_0.Op != OpMIPS64DIVVU {
			break
		}
		_ = v_0.Args[1]
		v_0_1 := v_0.Args[1]
		if v_0_1.Op != OpMIPS64MOVVconst || auxIntToInt64(v_0_1.AuxInt) != 1 {
			break
		}
		v.reset(OpMIPS64MOVVconst)
		v.AuxInt = int64ToAuxInt(0)
		return true
	}
	// match: (Select0 (DIVVU x (MOVVconst [c])))
	// cond: isPowerOfTwo64(c)

		v.copyOf(x)
		return true
	}
	// match: (Select1 (AddTupleFirst32 _ tuple))
	// result: (Select1 tuple)
	for {
		if v_0.Op != OpAMD64AddTupleFirst32 {
			break
		}
		tuple := v_0.Args[1]
		v.reset(OpSelect1)
		v.AddArg(tuple)
		return true
	}
	// match: (Select1 (AddTupleFirst64 _ tuple))
	// result: (Select1 tuple)
	for {
		if v_0.Op != OpAMD64AddTupleFirst64 {

// to (Select0 (opCC x y)) without having to explicitly fixup every user
// of op.
//
// E.g consider the case:
// a = (ADD x y)
// b = (CMPconst [0] a)
// c = (OR a z)
//
// A rule like (CMPconst [0] (ADD x y)) => (CMPconst [0] (Select0 (ADDCC x y)))
// would produce:
// a  = (ADD x y)
// a' = (ADDCC x y)
// a” = (Select0 a')
// b  = (CMPconst [0] a”)

// div by constant
(Select0 (CALLudiv x (MOVWconst [1]))) => x
(Select1 (CALLudiv _ (MOVWconst [1]))) => (MOVWconst [0])
(Select0 (CALLudiv x (MOVWconst [c]))) && isPowerOfTwo32(c) => (SRLconst [int32(log32(c))] x)
(Select1 (CALLudiv x (MOVWconst [c]))) && isPowerOfTwo32(c) => (ANDconst [c-1] x)

// constant comparisons

(SelectN [0] (MakeResult x ___)) => x
(SelectN [1] (MakeResult x y ___)) => y
(SelectN [2] (MakeResult x y z ___)) => z

// for late-expanded calls, recognize newobject and remove zeroing and nilchecks
(Zero (SelectN [0] call:(StaticLECall _ _)) mem:(SelectN [1] call))
	&& isSameCall(call.Aux, "runtime.newobject")
	=> mem

		return true
	}
	// match: (MOVBUreg x:(Select0 (LoweredAtomicLoad8 _ _)))
	// result: (MOVDreg x)
	for {
		x := v_0
		if x.Op != OpSelect0 {
			break
		}
		x_0 := x.Args[0]
		if x_0.Op != OpRISCV64LoweredAtomicLoad8 {
			break
		}
		v.reset(OpRISCV64MOVDreg)
		v.AddArg(x)
		return true
	}
	// match: (MOVBUreg x:(Select0 (LoweredAtomicCas32 _ _ _ _)))
	// result: (MOVDreg x)

	}
	// match: (Move [64] dst src mem)
	// result: (STP [48] dst (Select0 <typ.UInt64> (LDP [48] src mem)) (Select1 <typ.UInt64> (LDP [48] src mem)) (STP [32] dst (Select0 <typ.UInt64> (LDP [32] src mem)) (Select1 <typ.UInt64> (LDP [32] src mem)) (STP [16] dst (Select0 <typ.UInt64> (LDP [16] src mem)) (Select1 <typ.UInt64> (LDP [16] src mem)) (STP dst (Select0 <typ.UInt64> (LDP src mem)) (Select1 <typ.UInt64> (LDP src mem)) mem))))
	for {

	// pseudo-ops for breaking Tuple
	{name: "Select0", argLength: 1, zeroWidth: true},  // the first component of a tuple
	{name: "Select1", argLength: 1, zeroWidth: true},  // the second component of a tuple
	{name: "SelectN", argLength: 1, aux: "Int64"},     // arg0=result, auxint=field index.  Returns the auxint'th member.

	v_0 := v.Args[0]
	b := v.Block
	// match: (Select0 (Mul64uhilo x y))
	// result: (MULHVU x y)
	for {
		if v_0.Op != OpMul64uhilo {
			break
		}
		y := v_0.Args[1]
		x := v_0.Args[0]
		v.reset(OpLOONG64MULHVU)
		v.AddArg2(x, y)
		return true
	}
	// match: (Select0 (Mul64uover x y))
	// result: (MULV x y)
	for {
		if v_0.Op != OpMul64uover {