\frac{1 - \tan x \cdot \tan x}{1 + \tan x \cdot \tan x}\log \left(e^{\frac{1 - \tan x \cdot \tan x}{\tan x \cdot \tan x + 1}}\right)double f(double x) {
double r1798683 = 1.0;
double r1798684 = x;
double r1798685 = tan(r1798684);
double r1798686 = r1798685 * r1798685;
double r1798687 = r1798683 - r1798686;
double r1798688 = r1798683 + r1798686;
double r1798689 = r1798687 / r1798688;
return r1798689;
}
double f(double x) {
double r1798690 = 1.0;
double r1798691 = x;
double r1798692 = tan(r1798691);
double r1798693 = r1798692 * r1798692;
double r1798694 = r1798690 - r1798693;
double r1798695 = r1798693 + r1798690;
double r1798696 = r1798694 / r1798695;
double r1798697 = exp(r1798696);
double r1798698 = log(r1798697);
return r1798698;
}



Bits error versus x
Results
Initial program 0.3
rmApplied add-log-exp0.4
Final simplification0.4
herbie shell --seed 2019121 +o rules:numerics
(FPCore (x)
:name "Trigonometry B"
(/ (- 1 (* (tan x) (tan x))) (+ 1 (* (tan x) (tan x)))))