Average Error: 6.9 → 2.2
Time: 3.4s
Precision: 64
\[\left(x \cdot y - z \cdot y\right) \cdot t\]
↓
\[\begin{array}{l} \mathbf{if}\;x \cdot y - z \cdot y \le -5.2825142284684672 \cdot 10^{125} \lor \neg \left(x \cdot y - z \cdot y \le 3.0182044239998063 \cdot 10^{117}\right):\\ \;\;\;\;\left(t \cdot y\right) \cdot \left(x - z\right)\\ \mathbf{else}:\\ \;\;\;\;\left(x \cdot y - z \cdot y\right) \cdot t\\ \end{array}\]
\left(x \cdot y - z \cdot y\right) \cdot t
↓
\begin{array}{l}
\mathbf{if}\;x \cdot y - z \cdot y \le -5.2825142284684672 \cdot 10^{125} \lor \neg \left(x \cdot y - z \cdot y \le 3.0182044239998063 \cdot 10^{117}\right):\\
\;\;\;\;\left(t \cdot y\right) \cdot \left(x - z\right)\\

\mathbf{else}:\\
\;\;\;\;\left(x \cdot y - z \cdot y\right) \cdot t\\

\end{array}
double f(double x, double y, double z, double t) {
        double r509906 = x;
        double r509907 = y;
        double r509908 = r509906 * r509907;
        double r509909 = z;
        double r509910 = r509909 * r509907;
        double r509911 = r509908 - r509910;
        double r509912 = t;
        double r509913 = r509911 * r509912;
        return r509913;
}
↓
double f(double x, double y, double z, double t) {
        double r509914 = x;
        double r509915 = y;
        double r509916 = r509914 * r509915;
        double r509917 = z;
        double r509918 = r509917 * r509915;
        double r509919 = r509916 - r509918;
        double r509920 = -5.282514228468467e+125;
        bool r509921 = r509919 <= r509920;
        double r509922 = 3.0182044239998063e+117;
        bool r509923 = r509919 <= r509922;
        double r509924 = !r509923;
        bool r509925 = r509921 || r509924;
        double r509926 = t;
        double r509927 = r509926 * r509915;
        double r509928 = r509914 - r509917;
        double r509929 = r509927 * r509928;
        double r509930 = r509919 * r509926;
        double r509931 = r509925 ? r509929 : r509930;
        return r509931;
}

Error

Bits error versus x

Bits error versus y

Bits error versus z

Bits error versus t

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original6.9
Target3.2
Herbie2.2
\[\begin{array}{l} \mathbf{if}\;t \lt -9.2318795828867769 \cdot 10^{-80}:\\ \;\;\;\;\left(y \cdot t\right) \cdot \left(x - z\right)\\ \mathbf{elif}\;t \lt 2.5430670515648771 \cdot 10^{83}:\\ \;\;\;\;y \cdot \left(t \cdot \left(x - z\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(y \cdot \left(x - z\right)\right) \cdot t\\ \end{array}\]

Derivation

  1. Split input into 2 regimes

  2. if (- (* x y) (* z y)) < -5.282514228468467e+125 or 3.0182044239998063e+117 < (- (* x y) (* z y))

    1. Initial program 17.9

      \[\left(x \cdot y - z \cdot y\right) \cdot t\]
    2. Using strategy rm

    3. Applied add-cube-cbrt18.7

      \[\leadsto \color{blue}{\left(\left(\sqrt[3]{x \cdot y - z \cdot y} \cdot \sqrt[3]{x \cdot y - z \cdot y}\right) \cdot \sqrt[3]{x \cdot y - z \cdot y}\right)} \cdot t\]

    4. Taylor expanded around inf 17.9

      \[\leadsto \color{blue}{t \cdot \left(x \cdot y\right) - t \cdot \left(z \cdot y\right)}\]

    5. Simplified2.7

      \[\leadsto \color{blue}{\left(t \cdot y\right) \cdot \left(x - z\right)}\]

    if -5.282514228468467e+125 < (- (* x y) (* z y)) < 3.0182044239998063e+117

    1. Initial program 1.9

      \[\left(x \cdot y - z \cdot y\right) \cdot t\]
  3. Recombined 2 regimes into one program.

  4. Final simplification2.2

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \cdot y - z \cdot y \le -5.2825142284684672 \cdot 10^{125} \lor \neg \left(x \cdot y - z \cdot y \le 3.0182044239998063 \cdot 10^{117}\right):\\ \;\;\;\;\left(t \cdot y\right) \cdot \left(x - z\right)\\ \mathbf{else}:\\ \;\;\;\;\left(x \cdot y - z \cdot y\right) \cdot t\\ \end{array}\]

Reproduce

herbie shell --seed 2020056 
(FPCore (x y z t)
  :name "Linear.Projection:inverseInfinitePerspective from linear-1.19.1.3"
  :precision binary64

  :herbie-target
  (if (< t -9.231879582886777e-80) (* (* y t) (- x z)) (if (< t 2.543067051564877e+83) (* y (* t (- x z))) (* (* y (- x z)) t)))

  (* (- (* x y) (* z y)) t))