\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot e^{-\left(1 + \varepsilon\right) \cdot x}}{2}\begin{array}{l}
\mathbf{if}\;x \le 5.301278737300282095645798108307644724846:\\
\;\;\;\;\frac{{x}^{3} \cdot 0.6666666666666667406815349750104360282421 + \left(2 - \left(x \cdot x\right) \cdot 1\right)}{2}\\
\mathbf{else}:\\
\;\;\;\;\frac{\sqrt[3]{\left(\frac{1}{\varepsilon} + 1\right) \cdot e^{\left(-x\right) \cdot \left(1 - \varepsilon\right)} - \left(\sqrt[3]{e^{\left(1 + \varepsilon\right) \cdot \left(-x\right)} \cdot \left(\frac{1}{\varepsilon} - 1\right)} \cdot \sqrt[3]{e^{\left(1 + \varepsilon\right) \cdot \left(-x\right)} \cdot \left(\frac{1}{\varepsilon} - 1\right)}\right) \cdot \sqrt[3]{e^{\left(1 + \varepsilon\right) \cdot \left(-x\right)} \cdot \left(\frac{1}{\varepsilon} - 1\right)}} \cdot \left(\sqrt[3]{\left(\frac{1}{\varepsilon} + 1\right) \cdot e^{\left(-x\right) \cdot \left(1 - \varepsilon\right)} - \left(\sqrt[3]{e^{\left(1 + \varepsilon\right) \cdot \left(-x\right)} \cdot \left(\frac{1}{\varepsilon} - 1\right)} \cdot \sqrt[3]{e^{\left(1 + \varepsilon\right) \cdot \left(-x\right)} \cdot \left(\frac{1}{\varepsilon} - 1\right)}\right) \cdot \sqrt[3]{e^{\left(1 + \varepsilon\right) \cdot \left(-x\right)} \cdot \left(\frac{1}{\varepsilon} - 1\right)}} \cdot \sqrt[3]{\left(\frac{1}{\varepsilon} + 1\right) \cdot e^{\left(-x\right) \cdot \left(1 - \varepsilon\right)} - \left(\sqrt[3]{e^{\left(1 + \varepsilon\right) \cdot \left(-x\right)} \cdot \left(\frac{1}{\varepsilon} - 1\right)} \cdot \sqrt[3]{e^{\left(1 + \varepsilon\right) \cdot \left(-x\right)} \cdot \left(\frac{1}{\varepsilon} - 1\right)}\right) \cdot \sqrt[3]{e^{\left(1 + \varepsilon\right) \cdot \left(-x\right)} \cdot \left(\frac{1}{\varepsilon} - 1\right)}}\right)}{2}\\
\end{array}double f(double x, double eps) {
double r441817 = 1.0;
double r441818 = eps;
double r441819 = r441817 / r441818;
double r441820 = r441817 + r441819;
double r441821 = r441817 - r441818;
double r441822 = x;
double r441823 = r441821 * r441822;
double r441824 = -r441823;
double r441825 = exp(r441824);
double r441826 = r441820 * r441825;
double r441827 = r441819 - r441817;
double r441828 = r441817 + r441818;
double r441829 = r441828 * r441822;
double r441830 = -r441829;
double r441831 = exp(r441830);
double r441832 = r441827 * r441831;
double r441833 = r441826 - r441832;
double r441834 = 2.0;
double r441835 = r441833 / r441834;
return r441835;
}
double f(double x, double eps) {
double r441836 = x;
double r441837 = 5.301278737300282;
bool r441838 = r441836 <= r441837;
double r441839 = 3.0;
double r441840 = pow(r441836, r441839);
double r441841 = 0.6666666666666667;
double r441842 = r441840 * r441841;
double r441843 = 2.0;
double r441844 = r441836 * r441836;
double r441845 = 1.0;
double r441846 = r441844 * r441845;
double r441847 = r441843 - r441846;
double r441848 = r441842 + r441847;
double r441849 = r441848 / r441843;
double r441850 = eps;
double r441851 = r441845 / r441850;
double r441852 = r441851 + r441845;
double r441853 = -r441836;
double r441854 = r441845 - r441850;
double r441855 = r441853 * r441854;
double r441856 = exp(r441855);
double r441857 = r441852 * r441856;
double r441858 = r441845 + r441850;
double r441859 = r441858 * r441853;
double r441860 = exp(r441859);
double r441861 = r441851 - r441845;
double r441862 = r441860 * r441861;
double r441863 = cbrt(r441862);
double r441864 = r441863 * r441863;
double r441865 = r441864 * r441863;
double r441866 = r441857 - r441865;
double r441867 = cbrt(r441866);
double r441868 = r441867 * r441867;
double r441869 = r441867 * r441868;
double r441870 = r441869 / r441843;
double r441871 = r441838 ? r441849 : r441870;
return r441871;
}



Bits error versus x



Bits error versus eps
Results
if x < 5.301278737300282Initial program 39.2
Taylor expanded around 0 1.2
Simplified1.2
if 5.301278737300282 < x Initial program 0.5
rmApplied add-cube-cbrt0.5
Simplified0.5
Simplified0.5
rmApplied add-cube-cbrt0.5
Final simplification1.0
herbie shell --seed 2019179
(FPCore (x eps)
:name "NMSE Section 6.1 mentioned, A"
(/ (- (* (+ 1.0 (/ 1.0 eps)) (exp (- (* (- 1.0 eps) x)))) (* (- (/ 1.0 eps) 1.0) (exp (- (* (+ 1.0 eps) x))))) 2.0))