static void ensureMinimumNumBitsSet (BigInteger& chans, int minNumChans) { int i = 0; while (chans.countNumberOfSetBits() < minNumChans) chans.setBit (i++); }
bool passesMillerRabin (const BigInteger& n, int iterations) { const BigInteger one (1), two (2); const BigInteger nMinusOne (n - one); BigInteger d (nMinusOne); const int s = d.findNextSetBit (0); d >>= s; BigInteger smallPrimes; int numBitsInSmallPrimes = 0; for (;;) { numBitsInSmallPrimes += 256; createSmallSieve (numBitsInSmallPrimes, smallPrimes); const int numPrimesFound = numBitsInSmallPrimes - smallPrimes.countNumberOfSetBits(); if (numPrimesFound > iterations + 1) break; } int smallPrime = 2; while (--iterations >= 0) { smallPrime = smallPrimes.findNextClearBit (smallPrime + 1); BigInteger r (smallPrime); r.exponentModulo (d, n); if (r != one && r != nMinusOne) { for (int j = 0; j < s; ++j) { r.exponentModulo (two, n); if (r == nMinusOne) break; } if (r != nMinusOne) return false; } } return true; }