Average Error: 15.5 → 0.2
Time: 2.0s
Precision: 64
\[\frac{\left(x \cdot 2\right) \cdot y}{x - y}\]
\[\begin{array}{l} \mathbf{if}\;y \le -2.5251409834127483 \cdot 10^{52} \lor \neg \left(y \le 1.226684745187438 \cdot 10^{-25}\right):\\ \;\;\;\;\frac{x \cdot 2}{\frac{x - y}{y}}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x - y} \cdot \left(y \cdot 2\right)\\ \end{array}\]
\frac{\left(x \cdot 2\right) \cdot y}{x - y}
\begin{array}{l}
\mathbf{if}\;y \le -2.5251409834127483 \cdot 10^{52} \lor \neg \left(y \le 1.226684745187438 \cdot 10^{-25}\right):\\
\;\;\;\;\frac{x \cdot 2}{\frac{x - y}{y}}\\

\mathbf{else}:\\
\;\;\;\;\frac{x}{x - y} \cdot \left(y \cdot 2\right)\\

\end{array}
double f(double x, double y) {
        double r585914 = x;
        double r585915 = 2.0;
        double r585916 = r585914 * r585915;
        double r585917 = y;
        double r585918 = r585916 * r585917;
        double r585919 = r585914 - r585917;
        double r585920 = r585918 / r585919;
        return r585920;
}

double f(double x, double y) {
        double r585921 = y;
        double r585922 = -2.5251409834127483e+52;
        bool r585923 = r585921 <= r585922;
        double r585924 = 1.226684745187438e-25;
        bool r585925 = r585921 <= r585924;
        double r585926 = !r585925;
        bool r585927 = r585923 || r585926;
        double r585928 = x;
        double r585929 = 2.0;
        double r585930 = r585928 * r585929;
        double r585931 = r585928 - r585921;
        double r585932 = r585931 / r585921;
        double r585933 = r585930 / r585932;
        double r585934 = r585928 / r585931;
        double r585935 = r585921 * r585929;
        double r585936 = r585934 * r585935;
        double r585937 = r585927 ? r585933 : r585936;
        return r585937;
}

Error

Bits error versus x

Bits error versus y

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original15.5
Target0.4
Herbie0.2
\[\begin{array}{l} \mathbf{if}\;x \lt -1.7210442634149447 \cdot 10^{81}:\\ \;\;\;\;\frac{2 \cdot x}{x - y} \cdot y\\ \mathbf{elif}\;x \lt 83645045635564432:\\ \;\;\;\;\frac{x \cdot 2}{\frac{x - y}{y}}\\ \mathbf{else}:\\ \;\;\;\;\frac{2 \cdot x}{x - y} \cdot y\\ \end{array}\]

Derivation

  1. Split input into 2 regimes
  2. if y < -2.5251409834127483e+52 or 1.226684745187438e-25 < y

    1. Initial program 17.4

      \[\frac{\left(x \cdot 2\right) \cdot y}{x - y}\]
    2. Using strategy rm
    3. Applied associate-/l*0.1

      \[\leadsto \color{blue}{\frac{x \cdot 2}{\frac{x - y}{y}}}\]

    if -2.5251409834127483e+52 < y < 1.226684745187438e-25

    1. Initial program 13.7

      \[\frac{\left(x \cdot 2\right) \cdot y}{x - y}\]
    2. Using strategy rm
    3. Applied associate-/l*14.3

      \[\leadsto \color{blue}{\frac{x \cdot 2}{\frac{x - y}{y}}}\]
    4. Using strategy rm
    5. Applied div-inv14.4

      \[\leadsto \frac{x \cdot 2}{\color{blue}{\left(x - y\right) \cdot \frac{1}{y}}}\]
    6. Applied times-frac0.4

      \[\leadsto \color{blue}{\frac{x}{x - y} \cdot \frac{2}{\frac{1}{y}}}\]
    7. Simplified0.2

      \[\leadsto \frac{x}{x - y} \cdot \color{blue}{\left(y \cdot 2\right)}\]
  3. Recombined 2 regimes into one program.
  4. Final simplification0.2

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \le -2.5251409834127483 \cdot 10^{52} \lor \neg \left(y \le 1.226684745187438 \cdot 10^{-25}\right):\\ \;\;\;\;\frac{x \cdot 2}{\frac{x - y}{y}}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x - y} \cdot \left(y \cdot 2\right)\\ \end{array}\]

Reproduce

herbie shell --seed 2020036 
(FPCore (x y)
  :name "Linear.Projection:perspective from linear-1.19.1.3, B"
  :precision binary64

  :herbie-target
  (if (< x -1.7210442634149447e+81) (* (/ (* 2 x) (- x y)) y) (if (< x 83645045635564432) (/ (* x 2) (/ (- x y) y)) (* (/ (* 2 x) (- x y)) y)))

  (/ (* (* x 2) y) (- x y)))