double f(double x, double eps) {
double r8247071 = x;
double r8247072 = eps;
double r8247073 = r8247071 + r8247072;
double r8247074 = tan(r8247073);
double r8247075 = tan(r8247071);
double r8247076 = r8247074 - r8247075;
return r8247076;
}
double f(double x, double eps) {
double r8247077 = eps;
double r8247078 = -1.1488643550373863e-31;
bool r8247079 = r8247077 <= r8247078;
double r8247080 = 1.0;
double r8247081 = x;
double r8247082 = tan(r8247081);
double r8247083 = tan(r8247077);
double r8247084 = r8247082 * r8247083;
double r8247085 = r8247080 - r8247084;
double r8247086 = r8247082 + r8247083;
double r8247087 = r8247085 / r8247086;
double r8247088 = r8247080 / r8247087;
double r8247089 = r8247088 * r8247088;
double r8247090 = r8247082 * r8247082;
double r8247091 = r8247089 - r8247090;
double r8247092 = r8247082 + r8247088;
double r8247093 = r8247091 / r8247092;
double r8247094 = 5.947598887208492e-69;
bool r8247095 = r8247077 <= r8247094;
double r8247096 = r8247077 + r8247081;
double r8247097 = r8247077 * r8247096;
double r8247098 = r8247081 * r8247097;
double r8247099 = r8247077 + r8247098;
double r8247100 = cos(r8247081);
double r8247101 = r8247100 * r8247086;
double r8247102 = sin(r8247081);
double r8247103 = r8247085 * r8247102;
double r8247104 = r8247101 - r8247103;
double r8247105 = r8247085 * r8247100;
double r8247106 = r8247104 / r8247105;
double r8247107 = r8247095 ? r8247099 : r8247106;
double r8247108 = r8247079 ? r8247093 : r8247107;
return r8247108;
}
\tan \left(x + \varepsilon\right) - \tan x
\begin{array}{l}
\mathbf{if}\;\varepsilon \le -1.1488643550373863 \cdot 10^{-31}:\\
\;\;\;\;\frac{\frac{1}{\frac{1 - \tan x \cdot \tan \varepsilon}{\tan x + \tan \varepsilon}} \cdot \frac{1}{\frac{1 - \tan x \cdot \tan \varepsilon}{\tan x + \tan \varepsilon}} - \tan x \cdot \tan x}{\tan x + \frac{1}{\frac{1 - \tan x \cdot \tan \varepsilon}{\tan x + \tan \varepsilon}}}\\
\mathbf{elif}\;\varepsilon \le 5.947598887208492 \cdot 10^{-69}:\\
\;\;\;\;\varepsilon + x \cdot \left(\varepsilon \cdot \left(\varepsilon + x\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{\cos x \cdot \left(\tan x + \tan \varepsilon\right) - \left(1 - \tan x \cdot \tan \varepsilon\right) \cdot \sin x}{\left(1 - \tan x \cdot \tan \varepsilon\right) \cdot \cos x}\\
\end{array}



Bits error versus x




Bits error versus eps
| Original | 37.0 |
|---|---|
| Target | 15.1 |
| Herbie | 15.2 |
if eps < -1.1488643550373863e-31Initial program 29.6
rmApplied tan-sum2.4
rmApplied *-un-lft-identity2.4
Applied associate-/l*2.5
rmApplied flip--2.6
if -1.1488643550373863e-31 < eps < 5.947598887208492e-69Initial program 46.6
Taylor expanded around 0 30.8
Simplified30.7
if 5.947598887208492e-69 < eps Initial program 30.4
rmApplied tan-quot30.3
Applied tan-sum5.3
Applied frac-sub5.3
Final simplification15.2
herbie shell --seed 2019101
(FPCore (x eps)
:name "2tan (problem 3.3.2)"
:herbie-target
(/ (sin eps) (* (cos x) (cos (+ x eps))))
(- (tan (+ x eps)) (tan x)))