/* If the requested operation results in an overflow or an underflow condition, then Result is set to UINTN_ERROR and RETURN_BUFFER_TOO_SMALL is returned. */
RETURN_STATUS EFIAPI SafeUintnSub(IN UINTN Minuend, IN UINTN Subtrahend, OUT UINTN *Result)
/* If the requested operation results in an overflow or an underflow condition, then Result is set to UINTN_ERROR and RETURN_BUFFER_TOO_SMALL is returned. */
RETURN_STATUS EFIAPI SafeUintnSub(IN UINTN Minuend, IN UINTN Subtrahend, OUT UINTN *Result)
{
  RETURN_STATUS  Status;
  if (Result == NULL) {
    return RETURN_INVALID_PARAMETER;
  }
  if (Minuend >= Subtrahend) {
    *Result = (Minuend - Subtrahend);
    Status  = RETURN_SUCCESS;
  } else {
    *Result = UINTN_ERROR;
    Status  = RETURN_BUFFER_TOO_SMALL;
  }
  return Status;
}