2 \cdot \cos \left(\frac{2 \cdot \pi}{3} + \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{3}\right)
\begin{array}{l}
t_0 := \frac{1}{\sqrt{3}} \cdot \frac{\cos^{-1} \left(\frac{-g}{h}\right)}{\sqrt{3}}\\
2 \cdot \left(\cos \left(\pi \cdot 0.6666666666666666\right) \cdot \cos t_0 - \sin \left(\mathsf{expm1}\left(\mathsf{log1p}\left(\pi \cdot 0.6666666666666666\right)\right)\right) \cdot \sin t_0\right)
\end{array}
(FPCore (g h) :precision binary64 (* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))
(FPCore (g h)
:precision binary64
(let* ((t_0 (* (/ 1.0 (sqrt 3.0)) (/ (acos (/ (- g) h)) (sqrt 3.0)))))
(*
2.0
(-
(* (cos (* PI 0.6666666666666666)) (cos t_0))
(* (sin (expm1 (log1p (* PI 0.6666666666666666)))) (sin t_0))))))double code(double g, double h) {
return 2.0 * cos(((2.0 * ((double) M_PI)) / 3.0) + (acos(-g / h) / 3.0));
}
double code(double g, double h) {
double t_0 = (1.0 / sqrt(3.0)) * (acos(-g / h) / sqrt(3.0));
return 2.0 * ((cos(((double) M_PI) * 0.6666666666666666) * cos(t_0)) - (sin(expm1(log1p(((double) M_PI) * 0.6666666666666666))) * sin(t_0)));
}



Bits error versus g



Bits error versus h
Results
Initial program 1.0
Simplified1.0
Applied add-sqr-sqrt_binary641.0
Applied *-un-lft-identity_binary641.0
Applied times-frac_binary641.0
Applied fma-udef_binary641.0
Applied cos-sum_binary641.0
Applied expm1-log1p-u_binary640.0
Final simplification0.0
herbie shell --seed 2022019
(FPCore (g h)
:name "2-ancestry mixing, negative discriminant"
:precision binary64
(* 2.0 (cos (+ (/ (* 2.0 PI) 3.0) (/ (acos (/ (- g) h)) 3.0)))))