// 2, 4 or 8 bytes respectively. The result is a single byte however
// other bytes might contain junk so a zero extension is required if
// the desired output type is larger than 1 byte.
(SumBytes2 x) => (ADDW (SRWconst <typ.UInt8> x [8]) x)
(SumBytes4 x) => (SumBytes2 (ADDW <typ.UInt16> (SRWconst <typ.UInt16> x [16]) x))
(SumBytes8 x) => (SumBytes4 (ADDW <typ.UInt32> (SRDconst <typ.UInt32> x [32]) x))

(Bswap64 ...) => (MOVDBR ...)

			argLength: 2,
			reg:       regInfo{inputs: []regMask{gp, r3}, outputs: []regMask{r2, r3}},
			asm:       "MLGR",
		},

		// pseudo operations to sum the output of the POPCNT instruction
		{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

	}
	return false
}
func rewriteValueS390X_OpPopCount16(v *Value) bool {
	v_0 := v.Args[0]
	b := v.Block
	typ := &b.Func.Config.Types
	// match: (PopCount16 x)
	// result: (MOVBZreg (SumBytes2 (POPCNT <typ.UInt16> x)))
	for {
		x := v_0
		v.reset(OpS390XMOVBZreg)
		v0 := b.NewValue0(v.Pos, OpS390XSumBytes2, typ.UInt8)
		v1 := b.NewValue0(v.Pos, OpS390XPOPCNT, typ.UInt16)
		v1.AddArg(x)

				{0, 23551}, // R0 R1 R2 R3 R4 R5 R6 R7 R8 R9 R11 R12 R14
			},
			outputs: []outputInfo{
				{0, 4}, // R2
				{1, 8}, // R3
			},
		},
	},
	{
		name:   "SumBytes2",
		argLen: 1,
		reg:    regInfo{},
	},
	{
		name:   "SumBytes4",
		argLen: 1,
		reg:    regInfo{},
	},
	{
		name:   "SumBytes8",
		argLen: 1,