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 r11339497 = x;
        double r11339498 = 1.0;
        double r11339499 = r11339497 + r11339498;
        double r11339500 = sqrt(r11339499);
        double r11339501 = sqrt(r11339497);
        double r11339502 = r11339500 - r11339501;
        double r11339503 = y;
        double r11339504 = r11339503 + r11339498;
        double r11339505 = sqrt(r11339504);
        double r11339506 = sqrt(r11339503);
        double r11339507 = r11339505 - r11339506;
        double r11339508 = r11339502 + r11339507;
        double r11339509 = z;
        double r11339510 = r11339509 + r11339498;
        double r11339511 = sqrt(r11339510);
        double r11339512 = sqrt(r11339509);
        double r11339513 = r11339511 - r11339512;
        double r11339514 = r11339508 + r11339513;
        double r11339515 = t;
        double r11339516 = r11339515 + r11339498;
        double r11339517 = sqrt(r11339516);
        double r11339518 = sqrt(r11339515);
        double r11339519 = r11339517 - r11339518;
        double r11339520 = r11339514 + r11339519;
        return r11339520;
}