\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(t \cdot \left(t \cdot \sqrt{3.999999999999999676487027278085939408227 \cdot 10^{-32}}\right)\right) \cdot \sqrt{3.999999999999999676487027278085939408227 \cdot 10^{-32}}double f(double t) {
double r59476 = 1.0;
double r59477 = t;
double r59478 = 2e-16;
double r59479 = r59477 * r59478;
double r59480 = r59476 + r59479;
double r59481 = r59480 * r59480;
double r59482 = -1.0;
double r59483 = 2.0;
double r59484 = r59483 * r59479;
double r59485 = r59482 - r59484;
double r59486 = r59481 + r59485;
return r59486;
}
double f(double t) {
double r59487 = t;
double r59488 = 3.9999999999999997e-32;
double r59489 = sqrt(r59488);
double r59490 = r59487 * r59489;
double r59491 = r59487 * r59490;
double r59492 = r59491 * r59489;
return r59492;
}




Bits error versus t
Results
| Original | 61.8 |
|---|---|
| Target | 50.6 |
| Herbie | 0.3 |
Initial program 61.8
Simplified50.6
Taylor expanded around 0 0.3
rmApplied add-sqr-sqrt0.3
Applied associate-*l*0.4
rmApplied sqr-pow0.4
Applied associate-*r*0.3
Simplified0.3
Final simplification0.3
herbie shell --seed 2019325 +o rules:numerics
(FPCore (t)
:name "fma_test1"
:precision binary64
:pre (<= 0.9 t 1.1)
:herbie-target
(fma (+ 1 (* t 2e-16)) (+ 1 (* t 2e-16)) (- -1 (* 2 (* t 2e-16))))
(+ (* (+ 1 (* t 2e-16)) (+ 1 (* t 2e-16))) (- -1 (* 2 (* t 2e-16)))))