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 r7987 = 1.0;
        double r7988 = atan2(1.0, 0.0);
        double r7989 = 4.0;
        double r7990 = r7988 / r7989;
        double r7991 = r7987 / r7990;
        double r7992 = f;
        double r7993 = r7990 * r7992;
        double r7994 = exp(r7993);
        double r7995 = -r7993;
        double r7996 = exp(r7995);
        double r7997 = r7994 + r7996;
        double r7998 = r7994 - r7996;
        double r7999 = r7997 / r7998;
        double r8000 = log(r7999);
        double r8001 = r7991 * r8000;
        double r8002 = -r8001;
        return r8002;
}