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 r7983 = 1.0;
        double r7984 = atan2(1.0, 0.0);
        double r7985 = 4.0;
        double r7986 = r7984 / r7985;
        double r7987 = r7983 / r7986;
        double r7988 = f;
        double r7989 = r7986 * r7988;
        double r7990 = exp(r7989);
        double r7991 = -r7989;
        double r7992 = exp(r7991);
        double r7993 = r7990 + r7992;
        double r7994 = r7990 - r7992;
        double r7995 = r7993 / r7994;
        double r7996 = log(r7995);
        double r7997 = r7987 * r7996;
        double r7998 = -r7997;
        return r7998;
}