\left(1 + t \cdot 1.999999999999999958195573448069207123682 \cdot 10^{-16}\right) \cdot \left(1 + t \cdot 1.999999999999999958195573448069207123682 \cdot 10^{-16}\right) + \left(-1 - 2 \cdot \left(t \cdot 1.999999999999999958195573448069207123682 \cdot 10^{-16}\right)\right)\left(\left(t \cdot \sqrt{3.999999999999999676487027278085939408227 \cdot 10^{-32}}\right) \cdot t\right) \cdot \sqrt{3.999999999999999676487027278085939408227 \cdot 10^{-32}}double f(double t) {
double r2925346 = 1.0;
double r2925347 = t;
double r2925348 = 2e-16;
double r2925349 = r2925347 * r2925348;
double r2925350 = r2925346 + r2925349;
double r2925351 = r2925350 * r2925350;
double r2925352 = -1.0;
double r2925353 = 2.0;
double r2925354 = r2925353 * r2925349;
double r2925355 = r2925352 - r2925354;
double r2925356 = r2925351 + r2925355;
return r2925356;
}
double f(double t) {
double r2925357 = t;
double r2925358 = 3.9999999999999997e-32;
double r2925359 = sqrt(r2925358);
double r2925360 = r2925357 * r2925359;
double r2925361 = r2925360 * r2925357;
double r2925362 = r2925361 * r2925359;
return r2925362;
}




Bits error versus t
Results
| Original | 61.8 |
|---|---|
| Target | 50.6 |
| Herbie | 0.3 |
Initial program 61.8
Taylor expanded around 0 0.3
Simplified0.3
rmApplied add-sqr-sqrt0.3
Applied associate-*r*0.4
rmApplied *-un-lft-identity0.4
Applied sqrt-prod0.4
Applied associate-*r*0.4
Simplified0.3
Final simplification0.3
herbie shell --seed 2019179
(FPCore (t)
:name "fma_test1"
:pre (<= 0.9 t 1.1)
:herbie-target
(fma (+ 1.0 (* t 2e-16)) (+ 1.0 (* t 2e-16)) (- -1.0 (* 2.0 (* t 2e-16))))
(+ (* (+ 1.0 (* t 2e-16)) (+ 1.0 (* t 2e-16))) (- -1.0 (* 2.0 (* t 2e-16)))))