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 r7985 = 1.0;
        double r7986 = atan2(1.0, 0.0);
        double r7987 = 4.0;
        double r7988 = r7986 / r7987;
        double r7989 = r7985 / r7988;
        double r7990 = f;
        double r7991 = r7988 * r7990;
        double r7992 = exp(r7991);
        double r7993 = -r7991;
        double r7994 = exp(r7993);
        double r7995 = r7992 + r7994;
        double r7996 = r7992 - r7994;
        double r7997 = r7995 / r7996;
        double r7998 = log(r7997);
        double r7999 = r7989 * r7998;
        double r8000 = -r7999;
        return r8000;
}