\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)t \cdot \left(t \cdot 3.999999999999999676487027278085939408227 \cdot 10^{-32}\right)double f(double t) {
double r54514 = 1.0;
double r54515 = t;
double r54516 = 2e-16;
double r54517 = r54515 * r54516;
double r54518 = r54514 + r54517;
double r54519 = r54518 * r54518;
double r54520 = -1.0;
double r54521 = 2.0;
double r54522 = r54521 * r54517;
double r54523 = r54520 - r54522;
double r54524 = r54519 + r54523;
return r54524;
}
double f(double t) {
double r54525 = t;
double r54526 = 3.9999999999999997e-32;
double r54527 = r54525 * r54526;
double r54528 = r54525 * r54527;
return r54528;
}




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 sqr-pow0.3
Applied associate-*r*0.3
Simplified0.3
Final simplification0.3
herbie shell --seed 2019304 +o rules:numerics
(FPCore (t)
:name "fma_test1"
:precision binary64
:pre (<= 0.900000000000000022 t 1.1000000000000001)
: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)))))