Cannot sample enough valid points. (more)

\[\left(\left(\left(\sqrt{x + 1.0} - \sqrt{x}\right) + \left(\sqrt{y + 1.0} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1.0} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1.0} - \sqrt{t}\right)\]
\left(\left(\left(\sqrt{x + 1.0} - \sqrt{x}\right) + \left(\sqrt{y + 1.0} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1.0} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1.0} - \sqrt{t}\right)
double f(double x, double y, double z, double t) {
        double r17545409 = x;
        double r17545410 = 1.0;
        double r17545411 = r17545409 + r17545410;
        double r17545412 = sqrt(r17545411);
        double r17545413 = sqrt(r17545409);
        double r17545414 = r17545412 - r17545413;
        double r17545415 = y;
        double r17545416 = r17545415 + r17545410;
        double r17545417 = sqrt(r17545416);
        double r17545418 = sqrt(r17545415);
        double r17545419 = r17545417 - r17545418;
        double r17545420 = r17545414 + r17545419;
        double r17545421 = z;
        double r17545422 = r17545421 + r17545410;
        double r17545423 = sqrt(r17545422);
        double r17545424 = sqrt(r17545421);
        double r17545425 = r17545423 - r17545424;
        double r17545426 = r17545420 + r17545425;
        double r17545427 = t;
        double r17545428 = r17545427 + r17545410;
        double r17545429 = sqrt(r17545428);
        double r17545430 = sqrt(r17545427);
        double r17545431 = r17545429 - r17545430;
        double r17545432 = r17545426 + r17545431;
        return r17545432;
}