//
(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

		{name: "SumBytes2", argLength: 1, typ: "UInt8"}, // sum the rightmost 2 bytes in arg0 ignoring overflow
		{name: "SumBytes4", argLength: 1, typ: "UInt8"}, // sum the rightmost 4 bytes in arg0 ignoring overflow
		{name: "SumBytes8", argLength: 1, typ: "UInt8"}, // sum all the bytes in arg0 ignoring overflow

		// store multiple
		{
			name:           "STMG2",
			argLength:      4,

		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)
		v1 := b.NewValue0(v.Pos, OpS390XPOPCNT, typ.UInt64)
		v1.AddArg(x)

		},
	},
	{
		name:   "SumBytes2",
		argLen: 1,
		reg:    regInfo{},
	},
	{
		name:   "SumBytes4",
		argLen: 1,
		reg:    regInfo{},
	},
	{
		name:   "SumBytes8",
		argLen: 1,
		reg:    regInfo{},
	},
	{
		name:           "STMG2",
		auxType:        auxSymOff,
		argLen:         4,
		clobberFlags:   true,
		faultOnNilArg0: true,