1 - \sqrt{0.5 \cdot \left(1 + \frac{1}{\mathsf{hypot}\left(1, x\right)}\right)}\frac{\left(1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}\right) \cdot \left(-0.5 + 0.5 \cdot \mathsf{hypot}\left(1, x\right)\right)}{\left(1 + \sqrt{0.5 + \frac{0.5}{\mathsf{hypot}\left(1, x\right)}}\right) \cdot \left(\mathsf{hypot}\left(1, x\right) \cdot \left(1 + \sqrt{0.5 + \frac{0.5}{\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 (/ (* (+ 1.0 (sqrt (+ 0.5 (/ 0.5 (hypot 1.0 x))))) (+ -0.5 (* 0.5 (hypot 1.0 x)))) (* (+ 1.0 (sqrt (+ 0.5 (/ 0.5 (hypot 1.0 x))))) (* (hypot 1.0 x) (+ 1.0 (sqrt (+ 0.5 (/ 0.5 (hypot 1.0 x)))))))))
double code(double x) {
return 1.0 - sqrt(0.5 * (1.0 + (1.0 / hypot(1.0, x))));
}
double code(double x) {
return ((1.0 + sqrt(0.5 + (0.5 / hypot(1.0, x)))) * (-0.5 + (0.5 * hypot(1.0, x)))) / ((1.0 + sqrt(0.5 + (0.5 / hypot(1.0, x)))) * (hypot(1.0, x) * (1.0 + sqrt(0.5 + (0.5 / hypot(1.0, x))))));
}



Bits error versus x
Results
Initial program 15.3
Simplified15.3
rmApplied flip--_binary6415.3
Simplified14.8
rmApplied div-sub_binary6414.8
rmApplied sub-neg_binary6414.8
Simplified14.8
rmApplied frac-add_binary6414.8
Simplified14.8
Final simplification14.8
herbie shell --seed 2020233
(FPCore (x)
:name "Given's Rotation SVD example, simplified"
:precision binary64
(- 1.0 (sqrt (* 0.5 (+ 1.0 (/ 1.0 (hypot 1.0 x)))))))