Cannot sample enough valid points. (more)

\[-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right)\]
-\frac{1}{\frac{\pi}{4}} \cdot \log \left(\frac{e^{\frac{\pi}{4} \cdot f} + e^{-\frac{\pi}{4} \cdot f}}{e^{\frac{\pi}{4} \cdot f} - e^{-\frac{\pi}{4} \cdot f}}\right)
double f(double f) {
        double r64 = 1.0;
        double r65 = atan2(1.0, 0.0);
        double r66 = 4.0;
        double r67 = r65 / r66;
        double r68 = r64 / r67;
        double r69 = f;
        double r70 = r67 * r69;
        double r71 = exp(r70);
        double r72 = -r70;
        double r73 = exp(r72);
        double r74 = r71 + r73;
        double r75 = r71 - r73;
        double r76 = r74 / r75;
        double r77 = log(r76);
        double r78 = r68 * r77;
        double r79 = -r78;
        return r79;
}