private static void PowCore(uint power, ref FastReducer reducer,
ref BitsBuffer value, ref BitsBuffer result,
ref BitsBuffer temp)
{
// The big modulus pow algorithm for the last or
// the only power limb using square-and-multiply.
// NOTE: we're using a special reducer here,
// since it's additional overhead does pay off.
while (power != 0)
{
if ((power & 1) == 1)
{
result.MultiplySelf(ref value, ref temp);
result.Reduce(ref reducer);
}
if (power != 1)
{
value.SquareSelf(ref temp);
value.Reduce(ref reducer);
}
power = power >> 1;
}
}
public void Reduce(ref FastReducer reducer)
{
// Executes a modulo operation using an optimized reducer.
// Thus, no need of any switching here, happens in-line.
_length = reducer.Reduce(_bits, _length);
}
public void Reduce(ref FastReducer reducer)
{
// Executes a modulo operation using an optimized reducer.
// Thus, no need of any switching here, happens in-line.
_length = reducer.Reduce(_bits, _length);
}
private static void PowCore(uint power, ref FastReducer reducer,
ref BitsBuffer value, ref BitsBuffer result,
ref BitsBuffer temp)
{
// The big modulus pow algorithm for the last or
// the only power limb using square-and-multiply.
// NOTE: we're using a special reducer here,
// since it's additional overhead does pay off.
while (power != 0)
{
if ((power & 1) == 1)
{
result.MultiplySelf(ref value, ref temp);
result.Reduce(ref reducer);
}
if (power != 1)
{
value.SquareSelf(ref temp);
value.Reduce(ref reducer);
}
power = power >> 1;
}
}
private static void PowCore(uint[] power, ref FastReducer reducer,
ref BitsBuffer value, ref BitsBuffer result,
ref BitsBuffer temp)
{
// The big modulus pow algorithm for all but
// the last power limb using square-and-multiply.
// NOTE: we're using a special reducer here,
// since it's additional overhead does pay off.
for (int i = 0; i < power.Length - 1; i++)
{
uint p = power[i];
for (int j = 0; j < 32; j++)
{
if ((p & 1) == 1)
{
result.MultiplySelf(ref value, ref temp);
result.Reduce(ref reducer);
}
value.SquareSelf(ref temp);
value.Reduce(ref reducer);
p = p >> 1;
}
}
PowCore(power[power.Length - 1], ref reducer, ref value, ref result,
ref temp);
}
private static uint[] PowCore(uint power, uint[] modulus,
ref BitsBuffer value)
{
// Executes the big pow algorithm.
int size = value.GetSize();
BitsBuffer temp = new BitsBuffer(size, 0);
BitsBuffer result = new BitsBuffer(size, 1);
if (modulus.Length < ReducerThreshold)
{
PowCore(power, modulus, ref value, ref result, ref temp);
}
else
{
FastReducer reducer = new FastReducer(modulus);
PowCore(power, ref reducer, ref value, ref result, ref temp);
}
return result.GetBits();
}
