/// <include file='../../docs.xml'
/// path='docs/doc[@name="M:PeterO.Numbers.FastInteger.Negate"]/*'/>
internal FastInteger Negate()
{
this.CheckFrozen();
switch (this.integerMode)
{
case 0:
if (this.smallValue == Int32.MinValue)
{
// would overflow, convert to large
this.integerMode = 1;
this.mnum =
MutableNumber.FromEInteger(ValueNegativeInt32MinValue);
}
else
{
smallValue = -smallValue;
}
break;
case 1:
this.integerMode = 2;
this.largeValue = this.mnum.ToEInteger();
this.largeValue = -(EInteger)this.largeValue;
break;
case 2:
this.largeValue = -(EInteger)this.largeValue;
break;
default:
throw new InvalidOperationException();
}
return(this);
}
internal FastInteger Divide(int divisor)
{
this.CheckFrozen();
if (divisor != 0)
{
switch (this.integerMode)
{
case 0:
if (divisor == -1 && this.smallValue == Int32.MinValue)
{
// would overflow, convert to large
this.integerMode = 1;
this.mnum =
MutableNumber.FromEInteger(ValueNegativeInt32MinValue);
}
else
{
smallValue /= divisor;
}
break;
case 1:
this.integerMode = 2;
this.largeValue = this.mnum.ToEInteger();
this.largeValue /= (EInteger)divisor;
if (this.largeValue.IsZero)
{
this.integerMode = 0;
this.smallValue = 0;
}
break;
case 2:
this.largeValue /= (EInteger)divisor;
if (this.largeValue.IsZero)
{
this.integerMode = 0;
this.smallValue = 0;
}
break;
default:
throw new InvalidOperationException();
}
}
else
{
throw new DivideByZeroException();
}
return(this);
}
internal FastInteger Increment()
{
this.CheckFrozen();
if (this.integerMode == 0)
{
if (this.smallValue != Int32.MaxValue)
{
++this.smallValue;
}
else
{
this.integerMode = 1;
this.mnum = MutableNumber.FromEInteger(ValueNegativeInt32MinValue);
}
return(this);
}
return(this.AddInt(1));
}
internal FastInteger Decrement()
{
this.CheckFrozen();
if (this.integerMode == 0)
{
if (this.smallValue != Int32.MinValue)
{
--this.smallValue;
}
else
{
this.integerMode = 1;
this.mnum = MutableNumber.FromEInteger(ValueInt32MinValue);
this.mnum.SubtractInt(1);
}
return(this);
}
return(this.SubtractInt(1));
}
internal static FastInteger FromBig(EInteger bigintVal)
{
if (bigintVal.CanFitInInt32())
{
return(new FastInteger(bigintVal.ToInt32Unchecked()));
}
if (bigintVal.Sign > 0)
{
var fi = new FastInteger(0);
fi.integerMode = 1;
fi.mnum = MutableNumber.FromEInteger(bigintVal);
return(fi);
}
else
{
var fi = new FastInteger(0);
fi.integerMode = 2;
fi.largeValue = bigintVal;
return(fi);
}
}
internal static int[] GetLastWords(EInteger bigint, int numWords32Bit)
{
return
(MutableNumber.FromEInteger(bigint).GetLastWordsInternal(numWords32Bit));
}