// ~100 Cyc ex
public static ULong DivRem(ULong lowDividend, ULong highDividend, ULong lowDivisor, ULong highDivisor, out ULong lowRemainder, out ULong highRemainder, out ULong highResult)
{
unchecked {
if (0u != highDivisor)
{
if (0 <= (Long)highDivisor)
{
ULong lowProduct;
ULong highProduct;
ULong lowResult;
ULong t;
{
var cc = 0;
// CountLeadingZeros
// ? using CountLeadingZeros is better or not?
t = highDivisor;
for (; 0 <= (Long)t; t <<= 1)
{
++cc;
}
lowResult = MathEx.BigDivInternal(
lowDividend >> (ULong_Misc.BitSizeAsIntUnchecked - cc) | (highDividend << cc),
highDividend >> (ULong_Misc.BitSizeAsIntUnchecked - cc),
(lowDivisor >> (ULong_Misc.BitSizeAsIntUnchecked - cc)) | t);
}
t = lowResult * highDivisor;
lowProduct = MathEx.BigMul(lowResult, lowDivisor, out highProduct);
highProduct += t;
if (t > highProduct || highProduct > highDividend)
{
goto L_0001;
}
if (highDividend > highProduct || lowProduct <= lowDividend)
{
goto L_0002;
}
L_0001:
--lowResult;
highProduct = ((lowDivisor > lowProduct) ? (highProduct - highDivisor - 1u) : (highProduct - highDivisor));
lowProduct -= lowDivisor;
L_0002:
highResult = 0u;
highRemainder = ((lowProduct > lowDividend) ? (highDividend - highProduct - 1u) : (highDividend - highProduct));
lowRemainder = lowDividend - lowProduct;
return(lowResult);
}
else
{
highResult = 0u;
if (highDivisor <= highDividend && (highDivisor != highDividend || lowDivisor <= lowDividend))
{
lowRemainder = MathEx.SubtractUnchecked(lowDividend, highDividend, lowDivisor, highDivisor, out highRemainder);
return(1u);
}
else
{
highRemainder = highDividend;
lowRemainder = lowDividend;
return(0u);
}
}
}
else
{
ULong t;
highResult = Math.DivRem(highDividend, lowDivisor, out t);
highRemainder = 0u;
return(MathEx.BigDivRemInternal(lowDividend, t, lowDivisor, out lowRemainder));
}
}
}
