1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)}\frac{{0.5}^{3} - {\left(\frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)}^{3}}{\left(0.5 \cdot 0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)} \cdot \left(0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}\right)\right) \cdot \left(1 + \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)}\right)}(FPCore (x) :precision binary64 (- 1.0 (sqrt (* 0.5 (+ 1.0 (/ 1.0 (hypot 1.0 x)))))))
(FPCore (x) :precision binary64 (/ (- (pow 0.5 3.0) (pow (/ 0.5 (hypot 1.0 x)) 3.0)) (* (+ (* 0.5 0.5) (* (/ 0.5 (hypot 1.0 x)) (+ 0.5 (/ 0.5 (hypot 1.0 x))))) (+ 1.0 (sqrt (* 0.5 (+ 1.0 (/ 1.0 (hypot 1.0 x)))))))))
double code(double x) {
return ((double) (1.0 - ((double) sqrt(((double) (0.5 * ((double) (1.0 + (1.0 / ((double) hypot(1.0, x)))))))))));
}
double code(double x) {
return (((double) (((double) pow(0.5, 3.0)) - ((double) pow((0.5 / ((double) hypot(1.0, x))), 3.0)))) / ((double) (((double) (((double) (0.5 * 0.5)) + ((double) ((0.5 / ((double) hypot(1.0, x))) * ((double) (0.5 + (0.5 / ((double) hypot(1.0, x))))))))) * ((double) (1.0 + ((double) sqrt(((double) (0.5 * ((double) (1.0 + (1.0 / ((double) hypot(1.0, x))))))))))))));
}



Bits error versus x
Results
Initial program 15.4
rmApplied flip--15.4
Simplified15.0
Taylor expanded around 0 14.9
Simplified14.9
rmApplied flip3--15.0
Applied associate-/l/15.0
Simplified15.0
Final simplification15.0
herbie shell --seed 2020198
(FPCore (x)
:name "Given's Rotation SVD example, simplified"
:precision binary64
(- 1.0 (sqrt (* 0.5 (+ 1.0 (/ 1.0 (hypot 1.0 x)))))))