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 r8312 = 1.0;
        double r8313 = atan2(1.0, 0.0);
        double r8314 = 4.0;
        double r8315 = r8313 / r8314;
        double r8316 = r8312 / r8315;
        double r8317 = f;
        double r8318 = r8315 * r8317;
        double r8319 = exp(r8318);
        double r8320 = -r8318;
        double r8321 = exp(r8320);
        double r8322 = r8319 + r8321;
        double r8323 = r8319 - r8321;
        double r8324 = r8322 / r8323;
        double r8325 = log(r8324);
        double r8326 = r8316 * r8325;
        double r8327 = -r8326;
        return r8327;
}