\sqrt{0.5 \cdot \left(1 + \frac{x}{\sqrt{\left(4 \cdot p\right) \cdot p + x \cdot x}}\right)}\sqrt{0.5 \cdot \left(1 + \frac{1}{\sqrt{\sqrt{\left(4 \cdot p\right) \cdot p + x \cdot x}}} \cdot \left(\frac{\sqrt[3]{x}}{\frac{\left|\sqrt[3]{\sqrt{\left(4 \cdot p\right) \cdot p + x \cdot x}}\right|}{\sqrt[3]{x}}} \cdot \frac{\sqrt[3]{x}}{\sqrt{\sqrt[3]{\sqrt{\left(4 \cdot p\right) \cdot p + x \cdot x}}}}\right)\right)}double code(double p, double x) {
return ((double) sqrt(((double) (0.5 * ((double) (1.0 + ((double) (x / ((double) sqrt(((double) (((double) (((double) (4.0 * p)) * p)) + ((double) (x * x))))))))))))));
}
double code(double p, double x) {
return ((double) sqrt(((double) (0.5 * ((double) (1.0 + ((double) (((double) (1.0 / ((double) sqrt(((double) sqrt(((double) (((double) (((double) (4.0 * p)) * p)) + ((double) (x * x)))))))))) * ((double) (((double) (((double) cbrt(x)) / ((double) (((double) fabs(((double) cbrt(((double) sqrt(((double) (((double) (((double) (4.0 * p)) * p)) + ((double) (x * x)))))))))) / ((double) cbrt(x)))))) * ((double) (((double) cbrt(x)) / ((double) sqrt(((double) cbrt(((double) sqrt(((double) (((double) (((double) (4.0 * p)) * p)) + ((double) (x * x))))))))))))))))))))));
}




Bits error versus p




Bits error versus x
Results
| Original | 13.0 |
|---|---|
| Target | 13.0 |
| Herbie | 14.4 |
Initial program 13.0
rmApplied add-sqr-sqrt13.0
Applied sqrt-prod13.9
Applied *-un-lft-identity13.9
Applied times-frac13.9
rmApplied add-cube-cbrt14.4
Applied sqrt-prod14.4
Applied add-cube-cbrt14.4
Applied times-frac14.5
Simplified14.4
Final simplification14.4
herbie shell --seed 2020114 +o rules:numerics
(FPCore (p x)
:name "Given's Rotation SVD example"
:precision binary64
:pre (< 1e-150 (fabs x) 1e+150)
:herbie-target
(sqrt (+ 0.5 (/ (copysign 0.5 x) (hypot 1 (/ (* 2 p) x)))))
(sqrt (* 0.5 (+ 1 (/ x (sqrt (+ (* (* 4 p) p) (* x x))))))))