ALUSrc(value, flags, max_size=32):
  if flags == 0b0000:
    return BroadcastImmediateReference(value)

  if flags >> 2 == 0b01: // SEE HERE!
    ureg = value | (flags & 1) << 8
    if flags & 0b10:
      if max_size < 32:
        UNDEFINED()
      return BroadcastUReg32Reference(ureg >> 1)
    else:
      return BroadcastUReg16Reference(ureg)

  if flags & 0b11 == 0b00: UNDEFINED()

  cache_flag   = (flags & 0b11) == 0b10
  discard_flag = (flags & 0b11) == 0b11

  if flags >> 2 == 0b11 and max_size >= 64:
    if value & 1: UNDEFINED()
    return Reg64Reference(value >> 1, cache=cache_flag, discard=discard_flag)

  if flags >> 2 >= 0b10 and max_size >= 32:
    if flags >> 2 != 0b10: UNDEFINED()
    if value & 1: UNDEFINED()
    return Reg32Reference(value >> 1, cache=cache_flag, discard=discard_flag)

  if flags >> 2 >= 0b01 and max_size >= 16:
    if flags >> 2 != 0b01: UNDEFINED()			// Isn't this always undefined? After all, when "flags >> 2 == 0b01", then we go another branch (see other comment)
    return Reg16Reference(value, cache=cache_flag, discard=discard_flag)