public static Rational64 FromInt64Bits(Int64 bits)
{
var numerator = unchecked ((UInt32)bits);
var denominator = unchecked ((Int32)(bits >> 32));
var s = 0 > denominator;
if (s)
{
denominator = -denominator;
}
else
{
++denominator;
}
var d = EuclideanAlgorithm.GreatestCommonDivisorPartial(numerator, unchecked ((UInt32)denominator));
if (s)
{
return(new Rational64(unchecked (((UInt64)((UInt32)(-denominator) / d) << 32) | numerator / d)));
}
else
{
return(new Rational64(unchecked (((UInt64)((UInt32)denominator / d - 1) << 32) | numerator / d)));
}
}
public static UInt64 MultiplyAsRational128(Rational64 first, Rational64 second, out UInt64 bits_hi)
{
unchecked {
var first_numerator = (UInt32)first.bits;
var first_denominator = (Int32)(first.bits >> 32);
var second_numerator = (UInt32)second.bits;
var second_denominator = (Int32)(second.bits >> 32);
if (0 == first_numerator || 0 == second_numerator)
{
bits_hi = 0;
return(0);
}
var s = 0 > (first_denominator ^ second_denominator);
if (0 <= first_denominator)
{
++first_denominator;
}
else
{
first_denominator = -first_denominator;
}
if (0 <= second_denominator)
{
++second_denominator;
}
else
{
second_denominator = -second_denominator;
}
{
var d = EuclideanAlgorithm.GreatestCommonDivisorPartial((UInt32)first_denominator, second_numerator);
first_denominator = (Int32)((UInt32)first_denominator / d);
second_numerator /= d;
}
{
var d = EuclideanAlgorithm.GreatestCommonDivisorPartial(first_numerator, (UInt32)second_denominator);
first_numerator /= d;
second_denominator = (Int32)((UInt32)second_denominator / d);
}
var p = (UInt64)first_numerator * second_numerator;
var q = (Int64)((UInt64)(UInt32)first_denominator * (UInt32)second_denominator);
if (s)
{
q = -q;
}
else
{
--q;
}
bits_hi = (UInt64)q;
return(p);
}
}
public static Rational64 FromFraction(UInt32 numerator, Int32 denominator)
{
Contract.EnsuresOnThrow <DivideByZeroException>(0 == Contract.OldValue(denominator));
unchecked {
Int32 q;
if (denominator > 0)
{
q = denominator;
}
else if (0 > denominator)
{
q = -denominator;
}
else
{
(denominator / denominator).Ignore();
throw null;
}
if (0 == numerator)
{
return(default(Rational64));
}
var d = EuclideanAlgorithm.GreatestCommonDivisorPartial(numerator, (UInt32)q);
numerator /= d;
q /= (Int32)d;
if (denominator > 0)
{
--q;
}
else
{
q = -q;
}
return(new Rational64((UInt64)q << 32 | numerator));
}
}
public static Rational64 Multiply(Rational64 first, Rational64 second)
{
unchecked {
var first_numerator = (UInt32)first.bits;
var first_denominator = (Int32)(first.bits >> 32);
var second_numerator = (UInt32)second.bits;
var second_denominator = (Int32)(second.bits >> 32);
if (0 == first_numerator || 0 == second_numerator)
{
return(Zero);
}
var s = 0 > (first_denominator ^ second_denominator);
if (0 <= first_denominator)
{
++first_denominator;
}
else
{
first_denominator = -first_denominator;
}
if (0 <= second_denominator)
{
++second_denominator;
}
else
{
second_denominator = -second_denominator;
}
{
var d = EuclideanAlgorithm.GreatestCommonDivisorPartial((UInt32)first_denominator, second_numerator);
first_denominator = (Int32)((UInt32)first_denominator / d);
second_numerator /= d;
}
{
var d = EuclideanAlgorithm.GreatestCommonDivisorPartial(first_numerator, (UInt32)second_denominator);
first_numerator /= d;
second_denominator = (Int32)((UInt32)second_denominator / d);
}
/*
* var q = (Int64)((UInt64)(UInt32)first_denominator * (UInt32)second_denominator);
* if (s) {
* q = -q;
* } else {
* --q;
* }
* checked((Int32)q).Ignore();
* return new Rational64(checked(first_numerator * second_numerator) | (UInt64)q << 32);
*/
var p = (UInt64)first_numerator * second_numerator;
var q = (Int64)((UInt64)(UInt32)first_denominator * (UInt32)second_denominator);
p = checked ((UInt32)p);
checked (unchecked ((UInt32)Int32.MinValue) - unchecked ((UInt64)q)).Ignore();
if (s)
{
return(new Rational64((UInt64)(-q << 32) | p));
}
else
{
return(new Rational64((UInt64)(--q << 32) | p));
}
}
}
