x.doinit()
	y.doinit()
	C.mpz_tdiv_qr(&q.i[0], &r.i[0], &x.i[0], &y.i[0])
}

// GcdInt sets d to the greatest common divisor of a and b,
// which must be positive numbers.
// If x and y are not nil, GcdInt sets x and y such that d = a*x + b*y.
// If either a or b is not positive, GcdInt sets d = x = y = 0.
func GcdInt(d, x, y, a, b *Int) {
	d.doinit()
	x.doinit()
	y.doinit()
	a.doinit()
	b.doinit()

public class ApacheBenchmark {
  private enum Impl {
    GUAVA {
      @Override
      public double factorialDouble(int n) {
        return DoubleMath.factorial(n);
      }

      @Override
      public int gcdInt(int a, int b) {
        return IntMath.gcd(a, b);
      }

      @Override
      public long gcdLong(long a, long b) {
        return LongMath.gcd(a, b);
      }

      @Override