double code(double a, double b, double eps) {
return ((double) (((double) (eps * ((double) (((double) exp(((double) (((double) (a + b)) * eps)))) - 1.0)))) / ((double) (((double) (((double) exp(((double) (a * eps)))) - 1.0)) * ((double) (((double) exp(((double) (b * eps)))) - 1.0))))));
}
double code(double a, double b, double eps) {
double VAR;
if ((b <= -8.908678098616857e+104)) {
VAR = ((double) (((double) (eps * ((double) (((double) exp(((double) (eps * ((double) (b + a)))))) - 1.0)))) / ((double) (((double) (((double) (eps * a)) + ((double) (((double) (eps * eps)) * ((double) (((double) (a * ((double) (a * 0.5)))) + ((double) (eps * ((double) (0.16666666666666666 * ((double) pow(a, 3.0)))))))))))) * ((double) (((double) exp(((double) (b * eps)))) - 1.0))))));
} else {
VAR = ((double) (1.0 / b));
}
return VAR;
}




Bits error versus a




Bits error versus b




Bits error versus eps
Results
| Original | 60.4 |
|---|---|
| Target | 14.9 |
| Herbie | 31.7 |
if b < -8.9086780986168568e104Initial program 53.0
Taylor expanded around 0 45.3
Simplified45.0
if -8.9086780986168568e104 < b Initial program 61.7
Taylor expanded around 0 56.9
Simplified56.4
rmApplied associate-*l*56.2
Simplified56.2
Taylor expanded around inf 56.2
Simplified56.9
Taylor expanded around 0 29.4
Final simplification31.7
herbie shell --seed 2020179
(FPCore (a b eps)
:name "expq3 (problem 3.4.2)"
:precision binary64
:pre (and (< -1.0 eps) (< eps 1.0))
:herbie-target
(/ (+ a b) (* a b))
(/ (* eps (- (exp (* (+ a b) eps)) 1.0)) (* (- (exp (* a eps)) 1.0) (- (exp (* b eps)) 1.0))))