/// <summary>
/// Returns multiplier instance for given multiply mode.
/// </summary>
/// <param name="mode">Multiply mode.</param>
/// <returns>Multiplier instance.</returns>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="mode" /> is out of range.</exception>
public static IMultiplier GetMultiplier(MultiplyMode mode)
{
switch (mode)
{
case MultiplyMode.AutoFht:
return AutoFhtMultiplier;
case MultiplyMode.Classic:
return ClassicMultiplier;
default:
throw new ArgumentOutOfRangeException("mode");
}
}
/// <summary>
/// Returns multiplier instance for given multiply mode.
/// </summary>
/// <param name="mode">Multiply mode.</param>
/// <returns>Multiplier instance.</returns>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="mode" /> is out of range.</exception>
static public IMultiplier GetMultiplier(MultiplyMode mode)
{
switch (mode)
{
case MultiplyMode.AutoFht:
return(AutoFhtMultiplier);
case MultiplyMode.Classic:
return(ClassicMultiplier);
default:
throw new ArgumentOutOfRangeException("mode");
}
}
/// <summary>
/// Returns a specified big integer raised to the specified power.
/// </summary>
/// <param name="value">Number to raise.</param>
/// <param name="power">Power.</param>
/// <param name="multiplyMode">Multiply mode set explicitly.</param>
/// <returns>Number in given power.</returns>
/// <exception cref="ArgumentNullException"><paramref name="value" /> is a null reference.</exception>
static public IntX Pow(IntX value, uint power, MultiplyMode multiplyMode)
{
// Exception
if (ReferenceEquals(value, null))
{
throw new ArgumentNullException("value");
}
// Return one for zero pow
if (power == 0)
{
return(1);
}
// Return the number itself from a power of one
if (power == 1)
{
return(new IntX(value));
}
// Return zero for a zero
if (value._length == 0)
{
return(new IntX());
}
// Get first one bit
int msb = Bits.Msb(power);
// Get multiplier
IMultiplier multiplier = MultiplyManager.GetMultiplier(multiplyMode);
// Do actual raising
IntX res = value;
for (uint powerMask = 1U << (msb - 1); powerMask != 0; powerMask >>= 1)
{
// Always square
res = multiplier.Multiply(res, res);
// Maybe mul
if ((power & powerMask) != 0)
{
res = multiplier.Multiply(res, value);
}
}
return(res);
}
/// <summary>
/// Returns multiplier instance for given multiply mode.
/// </summary>
/// <param name="mode">Multiply mode.</param>
/// <returns>Multiplier instance.</returns>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="mode" /> is out of range.</exception>
public static IMultiplier GetMultiplier(MultiplyMode mode)
{
// Check value
if (!Enum.IsDefined(typeof(MultiplyMode), mode))
{
throw new ArgumentOutOfRangeException("mode");
}
switch (mode)
{
case MultiplyMode.AutoFht:
return AutoFhtMultiplier;
default:
return ClassicMultiplier;
}
}
/// <summary>
/// Returns multiplier instance for given multiply mode.
/// </summary>
/// <param name="mode">Multiply mode.</param>
/// <returns>Multiplier instance.</returns>
/// <exception cref="ArgumentOutOfRangeException"><paramref name="mode" /> is out of range.</exception>
static public IMultiplier GetMultiplier(MultiplyMode mode)
{
// Check value
//if (!Enum.IsDefined(typeof(MultiplyMode), mode))
//{
// throw new ArgumentOutOfRangeException("mode");
//}
switch (mode)
{
case MultiplyMode.AutoFht:
return(AutoFhtMultiplier);
default:
return(ClassicMultiplier);
}
}
/// <summary>
/// Returns a specified big integer raised to the specified power.
/// </summary>
/// <param name="value">Number to raise.</param>
/// <param name="power">Power.</param>
/// <param name="multiplyMode">Multiply mode set explicitly.</param>
/// <returns>Number in given power.</returns>
/// <exception cref="ArgumentNullException"><paramref name="value" /> is a null reference.</exception>
static public IntX Pow(IntX value, uint power, MultiplyMode multiplyMode)
{
// Exception
if (ReferenceEquals(value, null))
{
throw new ArgumentNullException("value");
}
// Return one for zero pow
if (power == 0) return 1;
// Return the number itself from a power of one
if (power == 1) return new IntX(value);
// Return zero for a zero
if (value._length == 0) return new IntX();
// Get first one bit
int msb = Bits.Msb(power);
// Get multiplier
IMultiplier multiplier = MultiplyManager.GetMultiplier(multiplyMode);
// Do actual raising
IntX res = value;
for (uint powerMask = 1U << (msb - 1); powerMask != 0; powerMask >>= 1)
{
// Always square
res = multiplier.Multiply(res, res);
// Maybe mul
if ((power & powerMask) != 0)
{
res = multiplier.Multiply(res, value);
}
}
return res;
}