// result: (RLDICL [encodePPC64RotateMask(0,m,64)] n)
	for {
		for _i0 := 0; _i0 <= 1; _i0, v_0, v_1 = _i0+1, v_1, v_0 {
			x := v_0
			if x.Op != OpPPC64MOVDconst {
				continue
			}
			m := auxIntToInt64(x.AuxInt)
			n := v_1
			if !(isPPC64ValidShiftMask(m)) {
				continue
			}
			v.reset(OpPPC64RLDICL)
			v.AuxInt = int64ToAuxInt(encodePPC64RotateMask(0, m, 64))
			v.AddArg(n)
			return true

		{name: "RLWINM", argLength: 1, reg: gp11, asm: "RLWNM", aux: "Int64"},                           // Rotate and mask by immediate "rlwinm". encodePPC64RotateMask describes aux
		{name: "RLWNM", argLength: 2, reg: gp21, asm: "RLWNM", aux: "Int64"},                            // Rotate and mask by "rlwnm". encodePPC64RotateMask describes aux