\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 254.14528551610528:\\
\;\;\;\;\frac{e^{e^{\log \left(\log \left(0.66666666666666674 \cdot {x}^{3} + \left(2 - 1 \cdot {x}^{2}\right)\right)\right)}}}{2}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(1 + \frac{1}{\varepsilon}\right) \cdot e^{-\left(1 - \varepsilon\right) \cdot x} - \left(\frac{1}{\varepsilon} - 1\right) \cdot {\left(e^{\sqrt[3]{-\left(1 + \varepsilon\right) \cdot x} \cdot \sqrt[3]{-\left(1 + \varepsilon\right) \cdot x}}\right)}^{\left(\sqrt[3]{-\left(1 + \varepsilon\right) \cdot x}\right)}}{2}\\
\end{array}double f(double x, double eps) {
double r41158 = 1.0;
double r41159 = eps;
double r41160 = r41158 / r41159;
double r41161 = r41158 + r41160;
double r41162 = r41158 - r41159;
double r41163 = x;
double r41164 = r41162 * r41163;
double r41165 = -r41164;
double r41166 = exp(r41165);
double r41167 = r41161 * r41166;
double r41168 = r41160 - r41158;
double r41169 = r41158 + r41159;
double r41170 = r41169 * r41163;
double r41171 = -r41170;
double r41172 = exp(r41171);
double r41173 = r41168 * r41172;
double r41174 = r41167 - r41173;
double r41175 = 2.0;
double r41176 = r41174 / r41175;
return r41176;
}
double f(double x, double eps) {
double r41177 = x;
double r41178 = 254.14528551610528;
bool r41179 = r41177 <= r41178;
double r41180 = 0.6666666666666667;
double r41181 = 3.0;
double r41182 = pow(r41177, r41181);
double r41183 = r41180 * r41182;
double r41184 = 2.0;
double r41185 = 1.0;
double r41186 = 2.0;
double r41187 = pow(r41177, r41186);
double r41188 = r41185 * r41187;
double r41189 = r41184 - r41188;
double r41190 = r41183 + r41189;
double r41191 = log(r41190);
double r41192 = log(r41191);
double r41193 = exp(r41192);
double r41194 = exp(r41193);
double r41195 = r41194 / r41184;
double r41196 = eps;
double r41197 = r41185 / r41196;
double r41198 = r41185 + r41197;
double r41199 = r41185 - r41196;
double r41200 = r41199 * r41177;
double r41201 = -r41200;
double r41202 = exp(r41201);
double r41203 = r41198 * r41202;
double r41204 = r41197 - r41185;
double r41205 = r41185 + r41196;
double r41206 = r41205 * r41177;
double r41207 = -r41206;
double r41208 = cbrt(r41207);
double r41209 = r41208 * r41208;
double r41210 = exp(r41209);
double r41211 = pow(r41210, r41208);
double r41212 = r41204 * r41211;
double r41213 = r41203 - r41212;
double r41214 = r41213 / r41184;
double r41215 = r41179 ? r41195 : r41214;
return r41215;
}



Bits error versus x



Bits error versus eps
Results
if x < 254.14528551610528Initial program 38.8
Taylor expanded around 0 1.3
rmApplied associate--l+1.3
rmApplied add-exp-log1.4
rmApplied add-exp-log1.4
if 254.14528551610528 < x Initial program 0.1
rmApplied add-cube-cbrt0.1
Applied exp-prod0.1
Final simplification1.1
herbie shell --seed 2020034
(FPCore (x eps)
:name "NMSE Section 6.1 mentioned, A"
:precision binary64
(/ (- (* (+ 1 (/ 1 eps)) (exp (- (* (- 1 eps) x)))) (* (- (/ 1 eps) 1) (exp (- (* (+ 1 eps) x))))) 2))