x - \frac{\log \left(\left(1 - y\right) + y \cdot e^{z}\right)}{t}\begin{array}{l}
\mathbf{if}\;z \le -6.064026063174626 \cdot 10^{45}:\\
\;\;\;\;x - \frac{\log \left(\sqrt{\left(1 - y\right) + y \cdot e^{z}}\right) + \log \left(\sqrt{\left(1 - y\right) + y \cdot e^{z}}\right)}{t}\\
\mathbf{elif}\;z \le 6.7485748775422916 \cdot 10^{-44}:\\
\;\;\;\;x - \left(1 \cdot \left(\left(z \cdot y\right) \cdot \frac{1}{t}\right) + \frac{\log 1}{t}\right)\\
\mathbf{else}:\\
\;\;\;\;x - \frac{\log \left(1 + y \cdot \left(\frac{1}{2} \cdot {z}^{2} + z\right)\right)}{t}\\
\end{array}double f(double x, double y, double z, double t) {
double r331605 = x;
double r331606 = 1.0;
double r331607 = y;
double r331608 = r331606 - r331607;
double r331609 = z;
double r331610 = exp(r331609);
double r331611 = r331607 * r331610;
double r331612 = r331608 + r331611;
double r331613 = log(r331612);
double r331614 = t;
double r331615 = r331613 / r331614;
double r331616 = r331605 - r331615;
return r331616;
}
double f(double x, double y, double z, double t) {
double r331617 = z;
double r331618 = -6.064026063174626e+45;
bool r331619 = r331617 <= r331618;
double r331620 = x;
double r331621 = 1.0;
double r331622 = y;
double r331623 = r331621 - r331622;
double r331624 = exp(r331617);
double r331625 = r331622 * r331624;
double r331626 = r331623 + r331625;
double r331627 = sqrt(r331626);
double r331628 = log(r331627);
double r331629 = r331628 + r331628;
double r331630 = t;
double r331631 = r331629 / r331630;
double r331632 = r331620 - r331631;
double r331633 = 6.748574877542292e-44;
bool r331634 = r331617 <= r331633;
double r331635 = r331617 * r331622;
double r331636 = 1.0;
double r331637 = r331636 / r331630;
double r331638 = r331635 * r331637;
double r331639 = r331621 * r331638;
double r331640 = log(r331621);
double r331641 = r331640 / r331630;
double r331642 = r331639 + r331641;
double r331643 = r331620 - r331642;
double r331644 = 0.5;
double r331645 = 2.0;
double r331646 = pow(r331617, r331645);
double r331647 = r331644 * r331646;
double r331648 = r331647 + r331617;
double r331649 = r331622 * r331648;
double r331650 = r331621 + r331649;
double r331651 = log(r331650);
double r331652 = r331651 / r331630;
double r331653 = r331620 - r331652;
double r331654 = r331634 ? r331643 : r331653;
double r331655 = r331619 ? r331632 : r331654;
return r331655;
}




Bits error versus x




Bits error versus y




Bits error versus z




Bits error versus t
Results
| Original | 24.6 |
|---|---|
| Target | 16.0 |
| Herbie | 9.2 |
if z < -6.064026063174626e+45Initial program 11.5
rmApplied add-sqr-sqrt11.6
Applied log-prod11.6
if -6.064026063174626e+45 < z < 6.748574877542292e-44Initial program 29.2
Taylor expanded around 0 8.2
Simplified8.2
Taylor expanded around 0 8.0
rmApplied div-inv8.0
if 6.748574877542292e-44 < z Initial program 25.7
Taylor expanded around 0 13.5
Simplified13.5
Final simplification9.2
herbie shell --seed 2020035
(FPCore (x y z t)
:name "System.Random.MWC.Distributions:truncatedExp from mwc-random-0.13.3.2"
:precision binary64
:herbie-target
(if (< z -2.8874623088207947e+119) (- (- x (/ (/ (- 0.5) (* y t)) (* z z))) (* (/ (- 0.5) (* y t)) (/ (/ 2 z) (* z z)))) (- x (/ (log (+ 1 (* z y))) t)))
(- x (/ (log (+ (- 1 y) (* y (exp z)))) t)))