Average Error: 14.9 → 0.2
Time: 1.9s
Precision: 64
\[\frac{\left(x \cdot 2\right) \cdot y}{x - y}\]
\[\begin{array}{l} \mathbf{if}\;x \le -2.316089910188541 \cdot 10^{57} \lor \neg \left(x \le 15954.868549912213\right):\\ \;\;\;\;\frac{x \cdot 2}{x - y} \cdot y\\ \mathbf{else}:\\ \;\;\;\;\left(x \cdot 2\right) \cdot \frac{y}{x - y}\\ \end{array}\]
\frac{\left(x \cdot 2\right) \cdot y}{x - y}
\begin{array}{l}
\mathbf{if}\;x \le -2.316089910188541 \cdot 10^{57} \lor \neg \left(x \le 15954.868549912213\right):\\
\;\;\;\;\frac{x \cdot 2}{x - y} \cdot y\\

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

\end{array}
double f(double x, double y) {
        double r639963 = x;
        double r639964 = 2.0;
        double r639965 = r639963 * r639964;
        double r639966 = y;
        double r639967 = r639965 * r639966;
        double r639968 = r639963 - r639966;
        double r639969 = r639967 / r639968;
        return r639969;
}

double f(double x, double y) {
        double r639970 = x;
        double r639971 = -2.3160899101885412e+57;
        bool r639972 = r639970 <= r639971;
        double r639973 = 15954.868549912213;
        bool r639974 = r639970 <= r639973;
        double r639975 = !r639974;
        bool r639976 = r639972 || r639975;
        double r639977 = 2.0;
        double r639978 = r639970 * r639977;
        double r639979 = y;
        double r639980 = r639970 - r639979;
        double r639981 = r639978 / r639980;
        double r639982 = r639981 * r639979;
        double r639983 = r639979 / r639980;
        double r639984 = r639978 * r639983;
        double r639985 = r639976 ? r639982 : r639984;
        return r639985;
}

Error

Bits error versus x

Bits error versus y

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original14.9
Target0.3
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 x < -2.3160899101885412e+57 or 15954.868549912213 < x

    1. Initial program 18.1

      \[\frac{\left(x \cdot 2\right) \cdot y}{x - y}\]
    2. Using strategy rm
    3. Applied associate-/l*16.4

      \[\leadsto \color{blue}{\frac{x \cdot 2}{\frac{x - y}{y}}}\]
    4. Using strategy rm
    5. Applied associate-/r/0.1

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

    if -2.3160899101885412e+57 < x < 15954.868549912213

    1. Initial program 12.3

      \[\frac{\left(x \cdot 2\right) \cdot y}{x - y}\]
    2. Using strategy rm
    3. Applied *-un-lft-identity12.3

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

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

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \le -2.316089910188541 \cdot 10^{57} \lor \neg \left(x \le 15954.868549912213\right):\\ \;\;\;\;\frac{x \cdot 2}{x - y} \cdot y\\ \mathbf{else}:\\ \;\;\;\;\left(x \cdot 2\right) \cdot \frac{y}{x - y}\\ \end{array}\]

Reproduce

herbie shell --seed 2020034 
(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)))