private static void _MulKara(ref BigInt C, ref BigInt B1, ref BigInt B2, signt ResultSign)
{
short B1Spart = B1.Spart;
short B2Spart = B2.Spart;
B1.Reduce();
B2.Reduce();
B2 = (BigInt)B1.SameSize(B2);
C.Resize((short)(2 * B1.Spart + 1));
if (B1.Spart <= SPART_LIMIT || ((B1Spart < SPART_LIMIT && (B2Spart - B1Spart) > SPART_LIMIT) || (B2Spart < SPART_LIMIT && (B1Spart - B2Spart) > SPART_LIMIT)))
{
_Mul(ref C, ref B1, ref B2, ResultSign);
}
else
{
B1.Reduce();
B2.Reduce();
short Part = B1.Spart < B2.Spart ? (short)(B1.Spart / 2) : (short)(B2.Spart / 2);
//short PartCopy = Part;
//while (PartCopy != 0 && PartCopy < (B1.Spart < B2.Spart ? B1.Spart : B2.Spart) && CELL_SIZE % PartCopy != 0)
//{
// PartCopy++;
//}
//if (PartCopy != 0 && CELL_SIZE % PartCopy == 0)
//{
// Part = PartCopy;
//}
//else
//{
// PartCopy = Part;
// while (PartCopy > 0 && CELL_SIZE % PartCopy != 0)
// {
// PartCopy--;
// }
// Part = PartCopy;
//}
B2 = (BigInt)B1.SameSize(B2);
BigInt D = new BigInt(B1.Size, 0), E = new BigInt(B1.Size, 0);
BigInt F = new BigInt(B1.Size, 0), G = new BigInt(B1.Size, 0);
BigInt Z0 = new BigInt(B1.Size, 0), Z1 = new BigInt(B1.Size, 0), Z2 = new BigInt(B1.Size, 0);
// C := Z2 * (Base ^ (2 * Part)) + (Z1 - Z2 - Z0) * (Base ^ Part) + Z0
B1.Split(ref D, ref E, Part);
B2.Split(ref F, ref G, Part);
// K = D + E
// L = F + G
BigInt K = D + E;
BigInt L = F + G;
// Z0 := E*G
// Z1 := K*L
// Z2 := D*F
_MulKara(ref Z0, ref E, ref G, ResultSign);
_MulKara(ref Z1, ref K, ref L, ResultSign);
_MulKara(ref Z2, ref D, ref F, ResultSign);
Z0.Reduce();
Z1.Reduce();
Z2.Reduce();
// Z2Copy = Z2 * (Base ^ (2 * Part))
BigInt Z2Copy = Z2.Clone();
for (int i = 0; i < 2 * Part; i++)
{
// Z2 * Base
// Base = 2 ^ CELL_SIZE
Z2Copy.ShiftLeft(CELL_SIZE);
}
// (Z1 - Z2 - Z0) * (Base ^ Part)
BigInt ZDiff = Z1 - Z2 - Z0;
for (int i = 0; i < Part; i++)
{
// ZDiff * Base
// Base = 2 ^ CELL_SIZE
ZDiff.ShiftLeft(CELL_SIZE);
}
C = Z2Copy + ZDiff + Z0;
C.Reduce();
}
}
