public static BigDecimal DividePrimitiveLongs(long scaledDividend, long scaledDivisor, int scale,
RoundingMode roundingMode)
{
long quotient = scaledDividend / scaledDivisor;
long remainder = scaledDividend % scaledDivisor;
int sign = System.Math.Sign(scaledDividend) * System.Math.Sign(scaledDivisor);
if (remainder != 0)
{
// Checking if: remainder * 2 >= scaledDivisor
int compRem; // 'compare to remainder'
compRem = BigDecimal.LongCompareTo(System.Math.Abs(remainder) << 1, System.Math.Abs(scaledDivisor));
// To look if there is a carry
quotient += BigDecimal.RoundingBehavior(((int)quotient) & 1, sign * (5 + compRem), roundingMode);
}
// Constructing the result with the appropriate unscaled value
return(BigDecimal.Create(quotient, scale));
}
public static BigDecimal DivideBigIntegers(BigInteger scaledDividend, BigInteger scaledDivisor, int scale,
RoundingMode roundingMode)
{
BigInteger remainder;
BigInteger quotient = BigMath.DivideAndRemainder(scaledDividend, scaledDivisor, out remainder);
if (remainder.Sign == 0)
{
return(new BigDecimal(quotient, scale));
}
int sign = scaledDividend.Sign * scaledDivisor.Sign;
int compRem; // 'compare to remainder'
if (scaledDivisor.BitLength < 63)
{
// 63 in order to avoid out of long after <<1
long rem = remainder.ToInt64();
long divisor = scaledDivisor.ToInt64();
compRem = BigDecimal.LongCompareTo(System.Math.Abs(rem) << 1, System.Math.Abs(divisor));
// To look if there is a carry
compRem = BigDecimal.RoundingBehavior(BigInteger.TestBit(quotient, 0) ? 1 : 0,
sign * (5 + compRem), roundingMode);
}
else
{
// Checking if: remainder * 2 >= scaledDivisor
compRem = BigMath.Abs(remainder).ShiftLeftOneBit().CompareTo(BigMath.Abs(scaledDivisor));
compRem = BigDecimal.RoundingBehavior(BigInteger.TestBit(quotient, 0) ? 1 : 0,
sign * (5 + compRem), roundingMode);
}
if (compRem != 0)
{
if (quotient.BitLength < 63)
{
return(BigDecimal.Create(quotient.ToInt64() + compRem, scale));
}
quotient += BigInteger.FromInt64(compRem);
return(new BigDecimal(quotient, scale));
}
// Constructing the result with the appropriate unscaled value
return(new BigDecimal(quotient, scale));
}
