Average Error: 14.7 → 1.5
Time: 1.8s
Precision: 64
\[\frac{\left(x \cdot 2\right) \cdot y}{x - y}\]
\[\begin{array}{l} \mathbf{if}\;y \le -5.57636306111153486 \cdot 10^{137} \lor \neg \left(y \le 2.19553327371823438 \cdot 10^{93}\right):\\ \;\;\;\;\frac{x \cdot 2}{\sqrt[3]{{\left(\frac{x}{y} - 1\right)}^{3}}}\\ \mathbf{else}:\\ \;\;\;\;\frac{x \cdot 2}{x - y} \cdot y\\ \end{array}\]
\frac{\left(x \cdot 2\right) \cdot y}{x - y}
\begin{array}{l}
\mathbf{if}\;y \le -5.57636306111153486 \cdot 10^{137} \lor \neg \left(y \le 2.19553327371823438 \cdot 10^{93}\right):\\
\;\;\;\;\frac{x \cdot 2}{\sqrt[3]{{\left(\frac{x}{y} - 1\right)}^{3}}}\\

\mathbf{else}:\\
\;\;\;\;\frac{x \cdot 2}{x - y} \cdot y\\

\end{array}
double f(double x, double y) {
        double r589881 = x;
        double r589882 = 2.0;
        double r589883 = r589881 * r589882;
        double r589884 = y;
        double r589885 = r589883 * r589884;
        double r589886 = r589881 - r589884;
        double r589887 = r589885 / r589886;
        return r589887;
}

double f(double x, double y) {
        double r589888 = y;
        double r589889 = -5.576363061111535e+137;
        bool r589890 = r589888 <= r589889;
        double r589891 = 2.1955332737182344e+93;
        bool r589892 = r589888 <= r589891;
        double r589893 = !r589892;
        bool r589894 = r589890 || r589893;
        double r589895 = x;
        double r589896 = 2.0;
        double r589897 = r589895 * r589896;
        double r589898 = r589895 / r589888;
        double r589899 = 1.0;
        double r589900 = r589898 - r589899;
        double r589901 = 3.0;
        double r589902 = pow(r589900, r589901);
        double r589903 = cbrt(r589902);
        double r589904 = r589897 / r589903;
        double r589905 = r589895 - r589888;
        double r589906 = r589897 / r589905;
        double r589907 = r589906 * r589888;
        double r589908 = r589894 ? r589904 : r589907;
        return r589908;
}

Error

Bits error versus x

Bits error versus y

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original14.7
Target0.3
Herbie1.5
\[\begin{array}{l} \mathbf{if}\;x \lt -1.7210442634149447 \cdot 10^{81}:\\ \;\;\;\;\frac{2 \cdot x}{x - y} \cdot y\\ \mathbf{elif}\;x \lt 83645045635564432:\\ \;\;\;\;\frac{x \cdot 2}{\frac{x - y}{y}}\\ \mathbf{else}:\\ \;\;\;\;\frac{2 \cdot x}{x - y} \cdot y\\ \end{array}\]

Derivation

  1. Split input into 2 regimes
  2. if y < -5.576363061111535e+137 or 2.1955332737182344e+93 < y

    1. Initial program 20.8

      \[\frac{\left(x \cdot 2\right) \cdot y}{x - y}\]
    2. Using strategy rm
    3. Applied associate-/l*0.0

      \[\leadsto \color{blue}{\frac{x \cdot 2}{\frac{x - y}{y}}}\]
    4. Using strategy rm
    5. Applied add-cbrt-cube62.5

      \[\leadsto \frac{x \cdot 2}{\frac{x - y}{\color{blue}{\sqrt[3]{\left(y \cdot y\right) \cdot y}}}}\]
    6. Applied add-cbrt-cube63.1

      \[\leadsto \frac{x \cdot 2}{\frac{\color{blue}{\sqrt[3]{\left(\left(x - y\right) \cdot \left(x - y\right)\right) \cdot \left(x - y\right)}}}{\sqrt[3]{\left(y \cdot y\right) \cdot y}}}\]
    7. Applied cbrt-undiv63.1

      \[\leadsto \frac{x \cdot 2}{\color{blue}{\sqrt[3]{\frac{\left(\left(x - y\right) \cdot \left(x - y\right)\right) \cdot \left(x - y\right)}{\left(y \cdot y\right) \cdot y}}}}\]
    8. Simplified2.1

      \[\leadsto \frac{x \cdot 2}{\sqrt[3]{\color{blue}{{\left(\frac{x}{y} - 1\right)}^{3}}}}\]

    if -5.576363061111535e+137 < y < 2.1955332737182344e+93

    1. Initial program 12.0

      \[\frac{\left(x \cdot 2\right) \cdot y}{x - y}\]
    2. Using strategy rm
    3. Applied associate-/l*11.0

      \[\leadsto \color{blue}{\frac{x \cdot 2}{\frac{x - y}{y}}}\]
    4. Using strategy rm
    5. Applied associate-/r/1.3

      \[\leadsto \color{blue}{\frac{x \cdot 2}{x - y} \cdot y}\]
  3. Recombined 2 regimes into one program.
  4. Final simplification1.5

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \le -5.57636306111153486 \cdot 10^{137} \lor \neg \left(y \le 2.19553327371823438 \cdot 10^{93}\right):\\ \;\;\;\;\frac{x \cdot 2}{\sqrt[3]{{\left(\frac{x}{y} - 1\right)}^{3}}}\\ \mathbf{else}:\\ \;\;\;\;\frac{x \cdot 2}{x - y} \cdot y\\ \end{array}\]

Reproduce

herbie shell --seed 2020062 
(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)))