\pi \cdot \ell - \frac{1}{F \cdot F} \cdot \tan \left(\pi \cdot \ell\right)\pi \cdot \ell - \left(\tan \left(\sqrt{\pi} \cdot \left(\ell \cdot \left(\sqrt{\sqrt{\pi}} \cdot \sqrt{\sqrt{\pi}}\right)\right)\right) \cdot \frac{\sqrt{1}}{F}\right) \cdot \frac{\sqrt{1}}{F}double f(double F, double l) {
double r896034 = atan2(1.0, 0.0);
double r896035 = l;
double r896036 = r896034 * r896035;
double r896037 = 1.0;
double r896038 = F;
double r896039 = r896038 * r896038;
double r896040 = r896037 / r896039;
double r896041 = tan(r896036);
double r896042 = r896040 * r896041;
double r896043 = r896036 - r896042;
return r896043;
}
double f(double F, double l) {
double r896044 = atan2(1.0, 0.0);
double r896045 = l;
double r896046 = r896044 * r896045;
double r896047 = sqrt(r896044);
double r896048 = sqrt(r896047);
double r896049 = r896048 * r896048;
double r896050 = r896045 * r896049;
double r896051 = r896047 * r896050;
double r896052 = tan(r896051);
double r896053 = 1.0;
double r896054 = sqrt(r896053);
double r896055 = F;
double r896056 = r896054 / r896055;
double r896057 = r896052 * r896056;
double r896058 = r896057 * r896056;
double r896059 = r896046 - r896058;
return r896059;
}



Bits error versus F



Bits error versus l
Results
Initial program 16.6
rmApplied add-sqr-sqrt16.6
Applied times-frac16.6
Applied associate-*l*12.4
rmApplied add-sqr-sqrt12.5
Applied associate-*l*12.5
rmApplied add-sqr-sqrt12.5
Applied sqrt-prod12.4
Final simplification12.4
herbie shell --seed 2019172
(FPCore (F l)
:name "VandenBroeck and Keller, Equation (6)"
(- (* PI l) (* (/ 1.0 (* F F)) (tan (* PI l)))))