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



Bits error versus x
Results
Initial program 0.3
rmApplied clear-num0.4
rmApplied flip-+0.4
Applied associate-/l/0.4
rmApplied flip--0.4
Applied associate-*r/0.4
Simplified0.4
Final simplification0.4
herbie shell --seed 2020078 +o rules:numerics
(FPCore (x)
:name "Trigonometry B"
:precision binary64
(/ (- 1 (* (tan x) (tan x))) (+ 1 (* (tan x) (tan x)))))