(Ctz16 x) => (I64Ctz (I64Or x (I64Const [0x10000])))
(Ctz8  x) => (I64Ctz (I64Or x (I64Const [0x100])))

(Ctz(64|32|16|8)NonZero ...) => (I64Ctz ...)

(BitLen64 x) => (I64Sub (I64Const [64]) (I64Clz x))

(PopCount64 ...) => (I64Popcnt ...)
(PopCount32 x) => (I64Popcnt (ZeroExt32to64 x))
(PopCount16 x) => (I64Popcnt (ZeroExt16to64 x))
(PopCount8  x) => (I64Popcnt (ZeroExt8to64  x))

(CondSelect ...) => (Select ...)

	{name: "PopCount8", argLength: 1},  // Count bits in arg[0]
	{name: "PopCount16", argLength: 1}, // Count bits in arg[0]
	{name: "PopCount32", argLength: 1}, // Count bits in arg[0]
	{name: "PopCount64", argLength: 1}, // Count bits in arg[0]

	// RotateLeftX instructions rotate the X bits of arg[0] to the left
	// by the low lg_2(X) bits of arg[1], interpreted as an unsigned value.

(Ctz8 x)  => (POPCNTB (MOVBZreg (ANDN <typ.UInt8> (ADDconst <typ.UInt8> [-1] x) x)))

(BitLen64 x) => (SUBFCconst [64] (CNTLZD <typ.Int> x))
(BitLen32 x) => (SUBFCconst [32] (CNTLZW <typ.Int> x))

(PopCount64 ...) => (POPCNTD ...)
(PopCount(32|16|8) x) => (POPCNT(W|W|B) (MOV(W|H|B)Zreg x))

(And(64|32|16|8) ...) => (AND ...)
(Or(64|32|16|8) ...) => (OR ...)
(Xor(64|32|16|8) ...) => (XOR ...)

//
(PopCount8  x) => (POPCNT (MOVBZreg x))
(PopCount16 x) => (MOVBZreg (SumBytes2 (POPCNT <typ.UInt16> x)))
(PopCount32 x) => (MOVBZreg (SumBytes4 (POPCNT <typ.UInt32> x)))
(PopCount64 x) => (MOVBZreg (SumBytes8 (POPCNT <typ.UInt64> x)))

// SumBytes{2,4,8} pseudo operations sum the values of the rightmost
// 2, 4 or 8 bytes respectively. The result is a single byte however

(Ctz32 <t> x) => (CLZW (RBITW <t> x))
(Ctz16 <t> x) => (CLZW <t> (RBITW <typ.UInt32> (ORconst <typ.UInt32> [0x10000] x)))
(Ctz8  <t> x) => (CLZW <t> (RBITW <typ.UInt32> (ORconst <typ.UInt32> [0x100] x)))

(PopCount64 <t> x) => (FMOVDfpgp <t> (VUADDLV <typ.Float64> (VCNT <typ.Float64> (FMOVDgpfp <typ.Float64> x))))
(PopCount32 <t> x) => (FMOVDfpgp <t> (VUADDLV <typ.Float64> (VCNT <typ.Float64> (FMOVDgpfp <typ.Float64> (ZeroExt32to64 x)))))

		v0.AddArg(v1)
		v.AddArg(v0)
		return true
	}
}
func rewriteValueS390X_OpPopCount64(v *Value) bool {
	v_0 := v.Args[0]
	b := v.Block
	typ := &b.Func.Config.Types
	// match: (PopCount64 x)
	// result: (MOVBZreg (SumBytes8 (POPCNT <typ.UInt64> x)))
	for {
		x := v_0
		v.reset(OpS390XMOVBZreg)
		v0 := b.NewValue0(v.Pos, OpS390XSumBytes8, typ.UInt8)

		v0.AddArg(v1)
		v.AddArg(v0)
		return true
	}
}
func rewriteValueARM64_OpPopCount64(v *Value) bool {
	v_0 := v.Args[0]
	b := v.Block
	typ := &b.Func.Config.Types
	// match: (PopCount64 <t> x)
	// result: (FMOVDfpgp <t> (VUADDLV <typ.Float64> (VCNT <typ.Float64> (FMOVDgpfp <typ.Float64> x))))
	for {
		t := v.Type
		x := v_0
		v.reset(OpARM64FMOVDfpgp)
		v.Type = t

	},
	{
		name:    "PopCount16",
		argLen:  1,
		generic: true,
	},
	{
		name:    "PopCount32",
		argLen:  1,
		generic: true,
	},
	{
		name:    "PopCount64",
		argLen:  1,
		generic: true,
	},
	{
		name:    "RotateLeft64",
		argLen:  2,
		generic: true,
	},
	{
		name:    "RotateLeft32",
		argLen:  2,