Average Error: 25.0 → 0.7
Time: 28.3s
Precision: 64
\[x \cdot \sqrt{y \cdot y - z \cdot z}\]
↓
\[\begin{array}{l} \mathbf{if}\;y \le -2.794570820839950878036101099737855872471 \cdot 10^{-243}:\\ \;\;\;\;-x \cdot y\\ \mathbf{else}:\\ \;\;\;\;x \cdot y\\ \end{array}\]
x \cdot \sqrt{y \cdot y - z \cdot z}
↓
\begin{array}{l}
\mathbf{if}\;y \le -2.794570820839950878036101099737855872471 \cdot 10^{-243}:\\
\;\;\;\;-x \cdot y\\

\mathbf{else}:\\
\;\;\;\;x \cdot y\\

\end{array}
double f(double x, double y, double z) {
        double r464502 = x;
        double r464503 = y;
        double r464504 = r464503 * r464503;
        double r464505 = z;
        double r464506 = r464505 * r464505;
        double r464507 = r464504 - r464506;
        double r464508 = sqrt(r464507);
        double r464509 = r464502 * r464508;
        return r464509;
}
↓
double f(double x, double y, double __attribute__((unused)) z) {
        double r464510 = y;
        double r464511 = -2.794570820839951e-243;
        bool r464512 = r464510 <= r464511;
        double r464513 = x;
        double r464514 = r464513 * r464510;
        double r464515 = -r464514;
        double r464516 = r464512 ? r464515 : r464514;
        return r464516;
}

Error

Bits error versus x

Bits error versus y

Bits error versus z

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original25.0
Target0.6
Herbie0.7
\[\begin{array}{l} \mathbf{if}\;y \lt 2.581609648825169508994985860317034908583 \cdot 10^{-278}:\\ \;\;\;\;-x \cdot y\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\sqrt{y + z} \cdot \sqrt{y - z}\right)\\ \end{array}\]

Derivation

  1. Split input into 2 regimes

  2. if y < -2.794570820839951e-243

    1. Initial program 25.4

      \[x \cdot \sqrt{y \cdot y - z \cdot z}\]

    2. Taylor expanded around -inf 0.6

      \[\leadsto \color{blue}{-1 \cdot \left(x \cdot y\right)}\]

    3. Simplified0.6

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

    if -2.794570820839951e-243 < y

    1. Initial program 24.7

      \[x \cdot \sqrt{y \cdot y - z \cdot z}\]

    2. Taylor expanded around inf 0.9

      \[\leadsto x \cdot \color{blue}{y}\]
  3. Recombined 2 regimes into one program.

  4. Final simplification0.7

    \[\leadsto \begin{array}{l} \mathbf{if}\;y \le -2.794570820839950878036101099737855872471 \cdot 10^{-243}:\\ \;\;\;\;-x \cdot y\\ \mathbf{else}:\\ \;\;\;\;x \cdot y\\ \end{array}\]

Reproduce

herbie shell --seed 2019306 
(FPCore (x y z)
  :name "Diagrams.TwoD.Apollonian:initialConfig from diagrams-contrib-1.3.0.5, B"
  :precision binary64

  :herbie-target
  (if (< y 2.58160964882516951e-278) (- (* x y)) (* x (* (sqrt (+ y z)) (sqrt (- y z)))))

  (* x (sqrt (- (* y y) (* z z)))))