if r&(1<<uint(i)) != 0 {
			fmt.Fprintf(&buf, "%s%s", sep, Reg(i).String())
			sep = ","
		}
	}
	fmt.Fprintf(&buf, "}")
	return buf.String()
}

// An Endian is the argument to the SETEND instruction.
type Endian uint8

const (
	LittleEndian Endian = 0
	BigEndian    Endian = 1
)

func (Endian) IsArg() {}

func (e Endian) String() string {
	if e != 0 {
		return "BE"