\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 -7.147724553383306 \cdot 10^{+163}:\\
\;\;\;\;\frac{\mathsf{expm1}\left(\left(\left(a + b\right) \cdot \varepsilon\right)\right) \cdot \frac{\varepsilon}{\mathsf{expm1}\left(\left(a \cdot \varepsilon\right)\right)}}{\mathsf{expm1}\left(\left(\varepsilon \cdot b\right)\right)}\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{b} + \frac{1}{a}\\
\end{array}double f(double a, double b, double eps) {
double r4872480 = eps;
double r4872481 = a;
double r4872482 = b;
double r4872483 = r4872481 + r4872482;
double r4872484 = r4872483 * r4872480;
double r4872485 = exp(r4872484);
double r4872486 = 1.0;
double r4872487 = r4872485 - r4872486;
double r4872488 = r4872480 * r4872487;
double r4872489 = r4872481 * r4872480;
double r4872490 = exp(r4872489);
double r4872491 = r4872490 - r4872486;
double r4872492 = r4872482 * r4872480;
double r4872493 = exp(r4872492);
double r4872494 = r4872493 - r4872486;
double r4872495 = r4872491 * r4872494;
double r4872496 = r4872488 / r4872495;
return r4872496;
}
double f(double a, double b, double eps) {
double r4872497 = b;
double r4872498 = -7.147724553383306e+163;
bool r4872499 = r4872497 <= r4872498;
double r4872500 = a;
double r4872501 = r4872500 + r4872497;
double r4872502 = eps;
double r4872503 = r4872501 * r4872502;
double r4872504 = expm1(r4872503);
double r4872505 = r4872500 * r4872502;
double r4872506 = expm1(r4872505);
double r4872507 = r4872502 / r4872506;
double r4872508 = r4872504 * r4872507;
double r4872509 = r4872502 * r4872497;
double r4872510 = expm1(r4872509);
double r4872511 = r4872508 / r4872510;
double r4872512 = 1.0;
double r4872513 = r4872512 / r4872497;
double r4872514 = r4872512 / r4872500;
double r4872515 = r4872513 + r4872514;
double r4872516 = r4872499 ? r4872511 : r4872515;
return r4872516;
}




Bits error versus a




Bits error versus b




Bits error versus eps
Results
| Original | 58.5 |
|---|---|
| Target | 14.2 |
| Herbie | 3.7 |
if b < -7.147724553383306e+163Initial program 49.2
Simplified20.7
rmApplied *-un-lft-identity20.7
Applied times-frac15.6
Simplified15.6
if -7.147724553383306e+163 < b Initial program 59.5
Simplified35.8
Taylor expanded around 0 2.5
Final simplification3.7
herbie shell --seed 2019121 +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))))