\sqrt{0.5 \cdot \left(1 + \frac{x}{\sqrt{\left(4 \cdot p\right) \cdot p + x \cdot x}}\right)}\sqrt{0.5 \cdot \frac{{1}^{3} + {\left(\frac{x}{\sqrt{\left(4 \cdot p\right) \cdot p + x \cdot x}}\right)}^{3}}{\mathsf{fma}\left(\frac{\frac{x}{\sqrt{\mathsf{fma}\left(4 \cdot p, p, x \cdot x\right)}}}{\sqrt{\mathsf{fma}\left(4 \cdot p, p, x \cdot x\right)}}, x, 1 \cdot \left(1 - \frac{x}{\sqrt{\left(4 \cdot p\right) \cdot p + x \cdot x}}\right)\right)}}double code(double p, double x) {
return sqrt((0.5 * (1.0 + (x / sqrt((((4.0 * p) * p) + (x * x)))))));
}
double code(double p, double x) {
return sqrt((0.5 * ((pow(1.0, 3.0) + pow((x / sqrt((((4.0 * p) * p) + (x * x)))), 3.0)) / fma(((x / sqrt(fma((4.0 * p), p, (x * x)))) / sqrt(fma((4.0 * p), p, (x * x)))), x, (1.0 * (1.0 - (x / sqrt((((4.0 * p) * p) + (x * x))))))))));
}




Bits error versus p




Bits error versus x
Results
| Original | 13.1 |
|---|---|
| Target | 13.1 |
| Herbie | 13.1 |
Initial program 13.1
rmApplied flip3-+13.1
Simplified13.1
rmApplied add-sqr-sqrt13.1
Applied associate-/r*13.1
Final simplification13.1
herbie shell --seed 2020065 +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))))))))