public static UInt64 FromDecimalFallback(Decimal dec)
{
return(NativeImpl.fromFloat64((double)dec));
}
internal static UInt64 FromDecimalFloat64(Double x)
{
unchecked
{
UInt64 y = NativeImpl.fromFloat64(x);
// Using signed values because unsigned division optimizations are worse than signed
// in MS .NET, esp. Core2.0 while it should be opposite
Int64 m;
UInt64 signAndExp;
UInt64 notY = ~y;
if ((SpecialEncodingMask & notY) == 0)
{
// Special value or large coefficient
if ((InfinityMask & notY) == 0)
{
return(y); // Infinity etc.
}
m = (Int64)((y & LargeCoefficientMask) + LargeCoefficientHighBits);
//signAndExp = ((y << 2) & SmallCoefficientExponentMask) + (y & SignMask);
signAndExp = (y & LargeCoefficientExponentMask) * 4 + (y & SignMask);
if ((y & 1) != 0)
{
goto NeedAdjustment;
}
}
else
{
// "Normal" value
m = (Int64)(y & SmallCoefficientMask);
// 16 digits + odd
signAndExp = y & (UInt64.MaxValue << ExponentShiftSmall);
if ((y & 1) != 0 && (UInt64)m > MaxCoefficient / 10 + 1)
{
goto NeedAdjustment;
}
if (0 == m)
{
return(Zero);
}
}
NeedCanonize:
for (Int64 n = m; ;)
{
Int64 mNext = n / 10;
if (mNext * 10 != n)
{
return(signAndExp + (UInt64)n);
}
n = mNext;
signAndExp += 1L << ExponentShiftSmall;
}
NeedAdjustment:
// Check the last digit
Int64 m1 = m + 1;
m = m1 / 10;
if (m1 - m * 10 > 2)
{
return(y);
}
signAndExp += 1L << ExponentShiftSmall;
if (NativeImpl.toFloat64(signAndExp + (UInt64)m) != x)
{
return(y);
}
goto NeedCanonize;
}
}
public static Decimal64 FromDouble(Double value)
{
return(new Decimal64(NativeImpl.fromFloat64(value)));
}