\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)\sqrt{3.999999999999999676487027278085939408227 \cdot 10^{-32}} \cdot \left(\left(\left|t\right| \cdot \sqrt{3.999999999999999676487027278085939408227 \cdot 10^{-32}}\right) \cdot \sqrt{{t}^{2}}\right)double f(double t) {
double r67877 = 1.0;
double r67878 = t;
double r67879 = 2e-16;
double r67880 = r67878 * r67879;
double r67881 = r67877 + r67880;
double r67882 = r67881 * r67881;
double r67883 = -1.0;
double r67884 = 2.0;
double r67885 = r67884 * r67880;
double r67886 = r67883 - r67885;
double r67887 = r67882 + r67886;
return r67887;
}
double f(double t) {
double r67888 = 3.9999999999999997e-32;
double r67889 = sqrt(r67888);
double r67890 = t;
double r67891 = fabs(r67890);
double r67892 = r67891 * r67889;
double r67893 = 2.0;
double r67894 = pow(r67890, r67893);
double r67895 = sqrt(r67894);
double r67896 = r67892 * r67895;
double r67897 = r67889 * r67896;
return r67897;
}




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 add-sqr-sqrt0.4
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)))))