static private void FastMul(BigNumber aa, BigNumber bb, BigNumber rr)
{
int ii, k, nexp, sign;
BigNumber M_ain = new BigNumber();
BigNumber M_bin = new BigNumber();
BigNumber.Copy(aa, M_ain);
BigNumber.Copy(bb, M_bin);
int size_flag = GetSizeofInt();
int bit_limit = 8 * size_flag + 1;
sign = M_ain.signum * M_bin.signum;
nexp = M_ain.exponent + M_bin.exponent;
if (M_ain.dataLength >= M_bin.dataLength)
{
ii = M_ain.dataLength;
}
else
{
ii = M_bin.dataLength;
}
ii = (ii + 1) >> 1;
ii = NextPowerOfTwo(ii);
k = 2 * ii; /* required size of result, in bytes */
BigNumber.Pad(M_ain, k); /* fill out the data so the number of */
BigNumber.Pad(M_bin, k); /* bytes is an exact power of 2 */
if (k > rr.mantissa.Length)
{
BigNumber.Expand(rr, (k + 32));
}
BigNumber.FastMulFFT(rr.mantissa, M_ain.mantissa, M_bin.mantissa, ii);
rr.signum = (sbyte)sign;
rr.exponent = nexp;
rr.dataLength = 4 * ii;
BigNumber.Normalize(rr);
}