\frac{\varepsilon \cdot \left(e^{\left(a + b\right) \cdot \varepsilon} - 1\right)}{\left(e^{a \cdot \varepsilon} - 1\right) \cdot \left(e^{b \cdot \varepsilon} - 1\right)}\begin{array}{l}
\mathbf{if}\;b \le 1.2596314720077241 \cdot 10^{+207}:\\
\;\;\;\;\frac{1}{a} + \frac{1}{b}\\
\mathbf{else}:\\
\;\;\;\;\frac{\frac{\mathsf{expm1}\left(\left(\left(b + a\right) \cdot \varepsilon\right)\right) \cdot \varepsilon}{\mathsf{expm1}\left(\left(a \cdot \varepsilon\right)\right)}}{\mathsf{expm1}\left(\left(b \cdot \varepsilon\right)\right)}\\
\end{array}double f(double a, double b, double eps) {
double r7100252 = eps;
double r7100253 = a;
double r7100254 = b;
double r7100255 = r7100253 + r7100254;
double r7100256 = r7100255 * r7100252;
double r7100257 = exp(r7100256);
double r7100258 = 1.0;
double r7100259 = r7100257 - r7100258;
double r7100260 = r7100252 * r7100259;
double r7100261 = r7100253 * r7100252;
double r7100262 = exp(r7100261);
double r7100263 = r7100262 - r7100258;
double r7100264 = r7100254 * r7100252;
double r7100265 = exp(r7100264);
double r7100266 = r7100265 - r7100258;
double r7100267 = r7100263 * r7100266;
double r7100268 = r7100260 / r7100267;
return r7100268;
}
double f(double a, double b, double eps) {
double r7100269 = b;
double r7100270 = 1.2596314720077241e+207;
bool r7100271 = r7100269 <= r7100270;
double r7100272 = 1.0;
double r7100273 = a;
double r7100274 = r7100272 / r7100273;
double r7100275 = r7100272 / r7100269;
double r7100276 = r7100274 + r7100275;
double r7100277 = r7100269 + r7100273;
double r7100278 = eps;
double r7100279 = r7100277 * r7100278;
double r7100280 = expm1(r7100279);
double r7100281 = r7100280 * r7100278;
double r7100282 = r7100273 * r7100278;
double r7100283 = expm1(r7100282);
double r7100284 = r7100281 / r7100283;
double r7100285 = r7100269 * r7100278;
double r7100286 = expm1(r7100285);
double r7100287 = r7100284 / r7100286;
double r7100288 = r7100271 ? r7100276 : r7100287;
return r7100288;
}




Bits error versus a




Bits error versus b




Bits error versus eps
Results
| Original | 58.6 |
|---|---|
| Target | 13.7 |
| Herbie | 3.7 |
if b < 1.2596314720077241e+207Initial program 59.2
Simplified35.0
Taylor expanded around 0 2.7
if 1.2596314720077241e+207 < b Initial program 49.1
Simplified18.5
Taylor expanded around -inf 22.4
Simplified18.5
Final simplification3.7
herbie shell --seed 2019120 +o rules:numerics
(FPCore (a b eps)
:name "expq3 (problem 3.4.2)"
:pre (and (< -1 eps) (< eps 1))
:herbie-target
(/ (+ a b) (* a b))
(/ (* eps (- (exp (* (+ a b) eps)) 1)) (* (- (exp (* a eps)) 1) (- (exp (* b eps)) 1))))