Method ShortDivide

src/cryptlib/integer.cpp:1943–1980

}

word Integer::ShortDivide(Integer &quotient, const Integer &dividend, word divisor)
{
#ifdef THROW_EXCEPTIONS
    if (!divisor)
        throw Integer::DivideByZero();
#endif

    assert(divisor);

    if ((divisor & (divisor-1)) == 0)   // divisor is a power of 2
    {
        quotient = dividend >> (BitPrecision(divisor)-1);
        return dividend.reg[(unsigned int)0] & (divisor-1);
    }

    unsigned int i = dividend.WordCount();
    quotient.reg.CleanNew(RoundupSize(i));
    word remainder = 0;
    while (i--)
    {
        quotient.reg[i] = word(MAKE_DWORD(dividend.reg[i], remainder) / divisor);
        remainder = word(MAKE_DWORD(dividend.reg[i], remainder) % divisor);
    }

    if (dividend.NotNegative())
        quotient.sign = POSITIVE;
    else
    {
        quotient.sign = NEGATIVE;
        if (remainder)
        {
            --quotient;
            remainder = divisor - remainder;
        }
    }

    return remainder;
}

Integer operator/(const Integer &a, word b)
{