\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)
\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \frac{1}{\sqrt{1 + y} + \sqrt{y}}\right) + \frac{1}{\sqrt{1 + z} + \sqrt{z}}\right) + \left(\sqrt{1 + t} - \sqrt{t}\right)
(FPCore (x y z t) :precision binary64 (+ (+ (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y))) (- (sqrt (+ z 1.0)) (sqrt z))) (- (sqrt (+ t 1.0)) (sqrt t))))
(FPCore (x y z t) :precision binary64 (+ (+ (+ (- (sqrt (+ x 1.0)) (sqrt x)) (/ 1.0 (+ (sqrt (+ 1.0 y)) (sqrt y)))) (/ 1.0 (+ (sqrt (+ 1.0 z)) (sqrt z)))) (- (sqrt (+ 1.0 t)) (sqrt t))))
double code(double x, double y, double z, double t) {
return (((sqrt((x + 1.0)) - sqrt(x)) + (sqrt((y + 1.0)) - sqrt(y))) + (sqrt((z + 1.0)) - sqrt(z))) + (sqrt((t + 1.0)) - sqrt(t));
}
double code(double x, double y, double z, double t) {
return (((sqrt((x + 1.0)) - sqrt(x)) + (1.0 / (sqrt((1.0 + y)) + sqrt(y)))) + (1.0 / (sqrt((1.0 + z)) + sqrt(z)))) + (sqrt((1.0 + t)) - sqrt(t));
}




Bits error versus x




Bits error versus y




Bits error versus z




Bits error versus t
Results
| Original | 5.3 |
|---|---|
| Target | 1.5 |
| Herbie | 2.8 |
Initial program 5.3
Applied egg-rr5.0
Applied egg-rr4.7
Taylor expanded in y around 0 3.8
Taylor expanded in z around 0 2.8
Final simplification2.8
herbie shell --seed 2022130
(FPCore (x y z t)
:name "Main:z from "
:precision binary64
:herbie-target
(+ (+ (+ (/ 1.0 (+ (sqrt (+ x 1.0)) (sqrt x))) (/ 1.0 (+ (sqrt (+ y 1.0)) (sqrt y)))) (/ 1.0 (+ (sqrt (+ z 1.0)) (sqrt z)))) (- (sqrt (+ t 1.0)) (sqrt t)))
(+ (+ (+ (- (sqrt (+ x 1.0)) (sqrt x)) (- (sqrt (+ y 1.0)) (sqrt y))) (- (sqrt (+ z 1.0)) (sqrt z))) (- (sqrt (+ t 1.0)) (sqrt t))))