Return the smallest size int that can store the value

def _int_size(x):
    """Return the smallest size int that can store the value"""
    if -0x80 <= x <= 0x7F:
        return 1
    elif -0x8000 <= x <= 0x7FFF:
        return 2
    elif -0x80000000 <= x <= 0x7FFFFFFF:
        return 4
    elif long(-0x8000000000000000) <= x <= long(0x7FFFFFFFFFFFFFFF):
        return 8
    else:
        raise RuntimeError("Cannot represent value: " + str(x))