if reg > arm64.REG_R31 || reg < arm64.REG_R0 {
		return 0, errors.New("invalid register for shift operation")
	}
	return int64(reg&31)<<16 | int64(op)<<22 | int64(uint16(count)), nil
}

// ARM64RegisterExtension constructs an ARM64 register with extension or arrangement.
func ARM64RegisterExtension(a *obj.Addr, ext string, reg, num int16, isAmount, isIndex bool) error {