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 r7984 = 1.0;
        double r7985 = atan2(1.0, 0.0);
        double r7986 = 4.0;
        double r7987 = r7985 / r7986;
        double r7988 = r7984 / r7987;
        double r7989 = f;
        double r7990 = r7987 * r7989;
        double r7991 = exp(r7990);
        double r7992 = -r7990;
        double r7993 = exp(r7992);
        double r7994 = r7991 + r7993;
        double r7995 = r7991 - r7993;
        double r7996 = r7994 / r7995;
        double r7997 = log(r7996);
        double r7998 = r7988 * r7997;
        double r7999 = -r7998;
        return r7999;
}