X = ""
			if arg.Sign < 0 {
				X = "-"
			}
			X += gnuArg(inst, -1, arg.Index)
			if arg.Shift == ShiftLeft && arg.Count == 0 {
				// nothing
			} else if arg.Shift == RotateRightExt {
				X += ", rrx"
			} else {
				X += fmt.Sprintf(", %s #%d", strings.ToLower(arg.Shift.String()), arg.Count)
			}
		} else {
			X = fmt.Sprintf("#%d", arg.Offset)
		}

		switch arg.Mode {
		case AddrOffset:

	RotateRight      Shift = 3 // right rotate
	RotateRightExt   Shift = 4 // right rotate through carry (Count will always be 1)
)

var shiftName = [...]string{
	"LSL", "LSR", "ASR", "ROR", "RRX",
}

func (s Shift) String() string {
	if s < 5 {
		return shiftName[s]
	}
	return fmt.Sprintf("Shift(%d)", int(s))
}

// A RegShift is a register shifted by a constant.
type RegShift struct {