{name: "SRAW", argLength: 2, reg: gp21cxer, asm: "SRAW"}, // signed arg0 >> (arg1&63), 32 bit width
		{name: "SRD", argLength: 2, reg: gp21, asm: "SRD"},       // unsigned arg0 >> (arg1&127), 64 bit width
		{name: "SRW", argLength: 2, reg: gp21, asm: "SRW"},       // unsigned arg0 >> (arg1&63), 32 bit width
		{name: "SLD", argLength: 2, reg: gp21, asm: "SLD"},       // arg0 << (arg1&127), 64 bit width

		{name: "SRW", argLength: 2, reg: sh21, asm: "SRW"},                    // unsigned uint32(arg0) >> arg1, shift amount is mod 64
		{name: "SRDconst", argLength: 1, reg: gp11, asm: "SRD", aux: "UInt8"}, // unsigned arg0 >> auxint, shift amount 0-63
		{name: "SRWconst", argLength: 1, reg: gp11, asm: "SRW", aux: "UInt8"}, // unsigned uint32(arg0) >> auxint, shift amount 0-31

Examples:

	SRAD $8,R3,R4		=>	sradi r4,r3,8
	SRD $8,R3,R4		=>	rldicl r4,r3,56,8
	SLD $8,R3,R4		=>	rldicr r4,r3,8,55
	SRAW $16,R4,R5		=>	srawi r5,r4,16
	SRW $40,R4,R5		=>	rlwinm r5,r4,0,0,31
	SLW $12,R4,R5		=>	rlwinm r5,r4,12,0,19

Some non-simple shifts have operands in the Go assembly which don't map directly

	SLWCC R3, R4                    // 7c841831
	SLD $16, R3, R4                 // 786483e4
	SLD R3, R4, R5                  // 7c851836
	SLDCC R3, R4                    // 7c841837

	SRW $8, R3, R4                  // 5464c23e
	SRW R3, R4, R5                  // 7c851c30
	SRWCC R3, R4                    // 7c841c31
	SRAW $8, R3, R4                 // 7c644670
	SRAW R3, R4, R5                 // 7c851e30

	RLWNMCC:        "rlwnm.",
	SLW:            "slw",
	SLWCC:          "slw.",
	SRAW:           "sraw",
	SRAWCC:         "sraw.",
	SRAWI:          "srawi",
	SRAWICC:        "srawi.",
	SRW:            "srw",
	SRWCC:          "srw.",
	STB:            "stb",
	STBU:           "stbu",
	STBUX:          "stbux",
	STBX:           "stbx",
	STFD:           "stfd",
	STFDU:          "stfdu",
	STFDUX:         "stfdux",

	// match: (Rsh32Ux16 x y)
	// cond: shiftIsBounded(v)
	// result: (SRW x y)
	for {
		x := v_0
		y := v_1
		if !(shiftIsBounded(v)) {
			break
		}
		v.reset(OpPPC64SRW)
		v.AddArg2(x, y)
		return true
	}
	// match: (Rsh32Ux16 <t> x y)
	// result: (ISEL [2] (SRW <t> x y) (MOVDconst [0]) (CMPconst [0] (ANDconst [0xFFE0] y)))
	for {
		t := v.Type

(Lsh16x(64|32|16|8)  x y) && shiftIsBounded(v) => (SLD x y)
(Lsh8x(64|32|16|8)   x y) && shiftIsBounded(v) => (SLD x y)
(Rsh64Ux(64|32|16|8) x y) && shiftIsBounded(v) => (SRD x y)
(Rsh32Ux(64|32|16|8) x y) && shiftIsBounded(v) => (SRW x y)
(Rsh16Ux(64|32|16|8) x y) && shiftIsBounded(v) => (SRD (MOVHZreg x) y)
(Rsh8Ux(64|32|16|8)  x y) && shiftIsBounded(v) => (SRD (MOVBZreg x) y)
(Rsh64x(64|32|16|8)  x y) && shiftIsBounded(v) => (SRAD x y)

			},
			outputs: []outputInfo{
				{0, 1073733624}, // R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R14 R15 R16 R17 R18 R19 R20 R21 R22 R23 R24 R25 R26 R27 R28 R29
			},
		},
	},
	{
		name:   "SRW",
		argLen: 2,
		asm:    ppc64.ASRW,
		reg: regInfo{
			inputs: []inputInfo{
				{0, 1073733630}, // SP SB R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R14 R15 R16 R17 R18 R19 R20 R21 R22 R23 R24 R25 R26 R27 R28 R29