def is_even_for_rounding(c, exp):
    """General-purpose tiebreak used when rounding to even.
    If the significand is less than two bits,
    decide evenness based on the representation of the exponent.
    """
    if c.bit_length() > 1:
        return c & 1 == 0
    else:
        return exp & 1 == 0
