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 r8088 = 1.0;
        double r8089 = atan2(1.0, 0.0);
        double r8090 = 4.0;
        double r8091 = r8089 / r8090;
        double r8092 = r8088 / r8091;
        double r8093 = f;
        double r8094 = r8091 * r8093;
        double r8095 = exp(r8094);
        double r8096 = -r8094;
        double r8097 = exp(r8096);
        double r8098 = r8095 + r8097;
        double r8099 = r8095 - r8097;
        double r8100 = r8098 / r8099;
        double r8101 = log(r8100);
        double r8102 = r8092 * r8101;
        double r8103 = -r8102;
        return r8103;
}