double f(double x, double y) {
double r8645981 = x;
double r8645982 = y;
double r8645983 = r8645981 - r8645982;
double r8645984 = r8645981 + r8645982;
double r8645985 = r8645983 * r8645984;
double r8645986 = r8645981 * r8645981;
double r8645987 = r8645982 * r8645982;
double r8645988 = r8645986 + r8645987;
double r8645989 = r8645985 / r8645988;
return r8645989;
}
double f(double x, double y) {
double r8645990 = y;
double r8645991 = -1.3261488941008737e+154;
bool r8645992 = r8645990 <= r8645991;
double r8645993 = -1.0;
double r8645994 = -6.401413403488955e-157;
bool r8645995 = r8645990 <= r8645994;
double r8645996 = 1.0;
double r8645997 = x;
double r8645998 = r8645997 * r8645997;
double r8645999 = r8645990 * r8645990;
double r8646000 = r8645998 + r8645999;
double r8646001 = r8645997 - r8645990;
double r8646002 = r8645990 + r8645997;
double r8646003 = r8646001 * r8646002;
double r8646004 = r8646000 / r8646003;
double r8646005 = r8645996 / r8646004;
double r8646006 = 1.5746421432035006e-162;
bool r8646007 = r8645990 <= r8646006;
double r8646008 = r8646007 ? r8645996 : r8646005;
double r8646009 = r8645995 ? r8646005 : r8646008;
double r8646010 = r8645992 ? r8645993 : r8646009;
return r8646010;
}
\frac{\left(x - y\right) \cdot \left(x + y\right)}{x \cdot x + y \cdot y}\begin{array}{l}
\mathbf{if}\;y \le -1.3261488941008737 \cdot 10^{+154}:\\
\;\;\;\;-1\\
\mathbf{elif}\;y \le -6.401413403488955 \cdot 10^{-157}:\\
\;\;\;\;\frac{1}{\frac{x \cdot x + y \cdot y}{\left(x - y\right) \cdot \left(y + x\right)}}\\
\mathbf{elif}\;y \le 1.5746421432035006 \cdot 10^{-162}:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;\frac{1}{\frac{x \cdot x + y \cdot y}{\left(x - y\right) \cdot \left(y + x\right)}}\\
\end{array}



Bits error versus x




Bits error versus y
| Original | 19.5 |
|---|---|
| Target | 0.1 |
| Herbie | 4.9 |
if y < -1.3261488941008737e+154Initial program 63.6
Taylor expanded around 0 0
if -1.3261488941008737e+154 < y < -6.401413403488955e-157 or 1.5746421432035006e-162 < y Initial program 0.1
rmApplied clear-num0.1
if -6.401413403488955e-157 < y < 1.5746421432035006e-162Initial program 28.8
Taylor expanded around inf 15.4
Final simplification4.9
herbie shell --seed 2019101
(FPCore (x y)
:name "Kahan p9 Example"
:pre (and (< 0 x 1) (< y 1))
:herbie-target
(if (< 0.5 (fabs (/ x y)) 2) (/ (* (- x y) (+ x y)) (+ (* x x) (* y y))) (- 1 (/ 2 (+ 1 (* (/ x y) (/ x y))))))
(/ (* (- x y) (+ x y)) (+ (* x x) (* y y))))