@staticmethod
def from_register(reg: Register, double_flopped: bool) -> 'RGReg':
    return RGReg([RGField.from_field(fd) for fd in reg.fields], double_flopped)
@staticmethod
def from_register(reg: Register, double_flopped: bool) -> 'RGReg':
    return RGReg([RGField.from_field(fd) for fd in reg.fields], double_flopped)