public static unsafe ECPoint MultiplyAndAdd(ECPoint p1, Number scaler1, ECPoint p2, Number scaler2)
{
#if true
int l = scaler1.BitCount();
if (l < scaler2.BitCount())
{
l = scaler2.BitCount();
}
int * b1 = stackalloc int[l >> 2];
int * b2 = stackalloc int[l >> 2];
int * e1 = stackalloc int[l >> 2];
int * e2 = stackalloc int[l >> 2];
int d1 = ComputeSignedWindowDecomposition(scaler1, b1, e1) - 1;
int d2 = ComputeSignedWindowDecomposition(scaler2, b2, e2) - 1;
ECPoint[] p1ary = p1.SetupMultiplyHelperPoints();
ECPoint[] p2ary = p2.SetupMultiplyHelperPoints();
int lastE;
ECPoint Q;
if (e1[d1] == e2[d2])
{
Q = p1ary[b1[d1]].Add(p2ary[b2[d2--]]);
lastE = e1[d1--];
}
else if (e1[d1] > e2[d2])
{
Q = p1ary[b1[d1]];
lastE = e1[d1--];
}
else
{
Q = p2ary[b2[d2]];
lastE = e2[d2--];
}
while (d1 >= 0 || d2 >= 0)
{
int nextE;
int nextType = 0;
if (d1 >= 0 && d2 >= 0 && e1[d1] == e2[d2])
{
nextE = e1[d1];
nextType = 0;
}
else if ((d1 >= 0 && d2 < 0) || (d1 >= 0 && e1[d1] > e2[d2]))
{
nextE = e1[d1];
nextType = 1;
}
else
{
nextE = e2[d2];
nextType = 2;
}
for (int k = 0; k < lastE - nextE; k++)
{
Q = Q.Double();
}
if (nextType == 0 || nextType == 1)
{
if (b1[d1] > 0)
{
Q = Q.Add(p1ary[b1[d1--]]);
}
else
{
Q = Q.Add(p1ary[-b1[d1--]].Invert());
}
}
if (nextType == 0 || nextType == 2)
{
if (b2[d2] > 0)
{
Q = Q.Add(p2ary[b2[d2--]]);
}
else
{
Q = Q.Add(p2ary[-b2[d2--]].Invert());
}
}
lastE = nextE;
}
for (int k = 0; k < lastE; k++)
{
Q = Q.Double();
}
return(Q);
#else
int l = scaler1.BitCount();
if (l < scaler2.BitCount())
{
l = scaler2.BitCount();
}
ECPoint Z = p1.Add(p2);
ECPoint R = p1._field.GetInfinityPoint(p1._group);
for (int i = l - 1; i >= 0; i--)
{
R = R.Double();
uint ki = scaler1.GetBit(i);
uint li = scaler2.GetBit(i);
if (ki == 0)
{
if (li == 1)
{
R = R.Add(p2);
}
}
else
{
if (li == 0)
{
R = R.Add(p1);
}
else
{
R = R.Add(Z);
}
}
}
return(R);
#endif
}
public unsafe ECPoint Multiply(Number scaler)
{
ECPoint[] P = SetupMultiplyHelperPoints();
#if true
scaler = new Number(scaler, 1);
int l = scaler.BitCount() - 1;
int * b = stackalloc int [l >> 2];
int * e = stackalloc int[l >> 2];
int d = ComputeSignedWindowDecomposition(scaler, b, e);
ECPoint Q = P[b[d - 1]];
for (int i = d - 2; i >= 0; i--)
{
for (int k = 0; k < e[i + 1] - e[i]; k++)
{
Q = Q.Double();
}
if (b[i] > 0)
{
Q = Q.Add(P[b[i]]);
}
else
{
Q = Q.Add(P[-b[i]].Invert());
}
}
for (int k = 0; k < e[0]; k++)
{
Q = Q.Double();
}
#else
#if true
if (P == null)
{
P = _multiplyHelperPoints = new ECPoint[16];
P[1] = this;
P[2] = this.Double();
P[3] = P[1].Add(P[2]);
P[5] = P[3].Add(P[2]);
P[7] = P[5].Add(P[2]);
P[9] = P[7].Add(P[2]);
P[11] = P[9].Add(P[2]);
P[13] = P[11].Add(P[2]);
P[15] = P[13].Add(P[2]);
}
int j = scaler.BitCount() - 1;
ECPoint Q = _field.GetInfinityPoint(_group);
while (j >= 0)
{
if (scaler.GetBit(j) == 0)
{
Q = Q.Double();
j--;
}
else
{
int n = j - 1;
uint h = (1 << 3) | (scaler.GetBit(n--) << 2) | (scaler.GetBit(n--) << 1) | scaler.GetBit(n);
int t = j - 3;
while ((h & 1) == 0)
{
h >>= 1;
t++;
}
for (int i = 1; i <= j - t + 1; i++)
{
Q = Q.Double();
}
Q = Q.Add(P[(int)h]);
j = t - 1;
}
}
#else
ECPoint inv = Invert();
if (P == null)
{
P = _multiplyHelperPoints = new ECPoint[16];
P[1] = this;
P[2] = this.Double();
P[3] = P[1].Add(P[2]);
P[5] = P[3].Add(P[2]);
P[7] = P[5].Add(P[2]);
P[9] = P[7].Add(P[2]);
P[11] = P[9].Add(P[2]);
P[13] = P[11].Add(P[2]);
P[15] = P[13].Add(P[2]);
}
int j = scaler.BitCount() - 1;
ECPoint Q = _field.GetInfinityPoint(_group);
while (j >= 0)
{
uint continuous = scaler.GetContinuousBitCount(j);
if (continuous == 0)
{
Q = Q.Double();
j--;
}
else if (continuous <= 4)
{
int n = j - 1;
uint h = (1 << 3) | (scaler.GetBit(n--) << 2) | (scaler.GetBit(n--) << 1) | scaler.GetBit(n);
int t = j - 3;
while ((h & 1) == 0)
{
h >>= 1;
t++;
}
for (int i = 1; i <= j - t + 1; i++)
{
Q = Q.Double();
}
Q = Q.Add(P[(int)h]);
j = t - 1;
}
else
{
Q = Q.Add(this);
for (uint i = 0; i < continuous; i++)
{
Q = Q.Double();
}
Q = Q.Add(inv);
j -= (int)continuous;
}
}
#endif
#endif
return(Q);
}
