\frac{\cos th}{\sqrt{2}} \cdot \left(a1 \cdot a1\right) + \frac{\cos th}{\sqrt{2}} \cdot \left(a2 \cdot a2\right)\left(\frac{\cos th}{\sqrt{2}} \cdot a1\right) \cdot a1 + \frac{\frac{1}{\sqrt[3]{\sqrt{2}}}}{\sqrt[3]{\sqrt[3]{\sqrt{2}}} \cdot \sqrt[3]{\sqrt[3]{\sqrt{2}}}} \cdot \left(\left(\frac{\frac{\cos th}{\sqrt[3]{\sqrt{2}}}}{\sqrt[3]{\sqrt[3]{\sqrt{2}}}} \cdot a2\right) \cdot a2\right)double f(double a1, double a2, double th) {
double r89014 = th;
double r89015 = cos(r89014);
double r89016 = 2.0;
double r89017 = sqrt(r89016);
double r89018 = r89015 / r89017;
double r89019 = a1;
double r89020 = r89019 * r89019;
double r89021 = r89018 * r89020;
double r89022 = a2;
double r89023 = r89022 * r89022;
double r89024 = r89018 * r89023;
double r89025 = r89021 + r89024;
return r89025;
}
double f(double a1, double a2, double th) {
double r89026 = th;
double r89027 = cos(r89026);
double r89028 = 2.0;
double r89029 = sqrt(r89028);
double r89030 = r89027 / r89029;
double r89031 = a1;
double r89032 = r89030 * r89031;
double r89033 = r89032 * r89031;
double r89034 = 1.0;
double r89035 = cbrt(r89029);
double r89036 = r89034 / r89035;
double r89037 = cbrt(r89035);
double r89038 = r89037 * r89037;
double r89039 = r89036 / r89038;
double r89040 = r89027 / r89035;
double r89041 = r89040 / r89037;
double r89042 = a2;
double r89043 = r89041 * r89042;
double r89044 = r89043 * r89042;
double r89045 = r89039 * r89044;
double r89046 = r89033 + r89045;
return r89046;
}



Bits error versus a1



Bits error versus a2



Bits error versus th
Results
Initial program 0.5
rmApplied associate-*r*0.5
rmApplied add-cube-cbrt0.5
Applied associate-/r*0.5
rmApplied add-cube-cbrt0.5
Applied *-un-lft-identity0.5
Applied times-frac0.5
Applied times-frac0.5
Applied associate-*l*0.5
rmApplied associate-*r*0.5
Final simplification0.5
herbie shell --seed 2019325
(FPCore (a1 a2 th)
:name "Migdal et al, Equation (64)"
:precision binary64
(+ (* (/ (cos th) (sqrt 2)) (* a1 a1)) (* (/ (cos th) (sqrt 2)) (* a2 a2))))