Average Error: 21.5 → 0.6
Time: 6.2s
Precision: 64
\[\sqrt{x \cdot x + y}\]
↓
\[\begin{array}{l} \mathbf{if}\;x \le -1.337826701582892488089574244217473576524 \cdot 10^{154}:\\ \;\;\;\;\frac{\frac{-1}{2}}{\frac{x}{y}} - x\\ \mathbf{elif}\;x \le 1.417169030606568251689508094083542147075 \cdot 10^{48}:\\ \;\;\;\;\sqrt{x \cdot x + y}\\ \mathbf{else}:\\ \;\;\;\;\frac{y \cdot \frac{1}{2}}{x} + x\\ \end{array}\]
\sqrt{x \cdot x + y}
↓
\begin{array}{l}
\mathbf{if}\;x \le -1.337826701582892488089574244217473576524 \cdot 10^{154}:\\
\;\;\;\;\frac{\frac{-1}{2}}{\frac{x}{y}} - x\\

\mathbf{elif}\;x \le 1.417169030606568251689508094083542147075 \cdot 10^{48}:\\
\;\;\;\;\sqrt{x \cdot x + y}\\

\mathbf{else}:\\
\;\;\;\;\frac{y \cdot \frac{1}{2}}{x} + x\\

\end{array}
double f(double x, double y) {
        double r456249 = x;
        double r456250 = r456249 * r456249;
        double r456251 = y;
        double r456252 = r456250 + r456251;
        double r456253 = sqrt(r456252);
        return r456253;
}
↓
double f(double x, double y) {
        double r456254 = x;
        double r456255 = -1.3378267015828925e+154;
        bool r456256 = r456254 <= r456255;
        double r456257 = -0.5;
        double r456258 = y;
        double r456259 = r456254 / r456258;
        double r456260 = r456257 / r456259;
        double r456261 = r456260 - r456254;
        double r456262 = 1.4171690306065683e+48;
        bool r456263 = r456254 <= r456262;
        double r456264 = r456254 * r456254;
        double r456265 = r456264 + r456258;
        double r456266 = sqrt(r456265);
        double r456267 = 0.5;
        double r456268 = r456258 * r456267;
        double r456269 = r456268 / r456254;
        double r456270 = r456269 + r456254;
        double r456271 = r456263 ? r456266 : r456270;
        double r456272 = r456256 ? r456261 : r456271;
        return r456272;
}

Error

Bits error versus x

Bits error versus y

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original21.5
Target0.5
Herbie0.6
\[\begin{array}{l} \mathbf{if}\;x \lt -1.509769801047259255153812752081023359759 \cdot 10^{153}:\\ \;\;\;\;-\left(0.5 \cdot \frac{y}{x} + x\right)\\ \mathbf{elif}\;x \lt 5.582399551122540716781541767466805967807 \cdot 10^{57}:\\ \;\;\;\;\sqrt{x \cdot x + y}\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \frac{y}{x} + x\\ \end{array}\]

Derivation

  1. Split input into 3 regimes

  2. if x < -1.3378267015828925e+154

    1. Initial program 64.0

      \[\sqrt{x \cdot x + y}\]

    2. Taylor expanded around -inf 0

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

    3. Simplified0

      \[\leadsto \color{blue}{\frac{\frac{-1}{2}}{\frac{x}{y}} - x}\]

    if -1.3378267015828925e+154 < x < 1.4171690306065683e+48

    1. Initial program 0.0

      \[\sqrt{x \cdot x + y}\]

    if 1.4171690306065683e+48 < x

    1. Initial program 39.0

      \[\sqrt{x \cdot x + y}\]

    2. Taylor expanded around inf 2.0

      \[\leadsto \color{blue}{x + \frac{1}{2} \cdot \frac{y}{x}}\]

    3. Simplified2.0

      \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot y}{x} + x}\]
  3. Recombined 3 regimes into one program.

  4. Final simplification0.6

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \le -1.337826701582892488089574244217473576524 \cdot 10^{154}:\\ \;\;\;\;\frac{\frac{-1}{2}}{\frac{x}{y}} - x\\ \mathbf{elif}\;x \le 1.417169030606568251689508094083542147075 \cdot 10^{48}:\\ \;\;\;\;\sqrt{x \cdot x + y}\\ \mathbf{else}:\\ \;\;\;\;\frac{y \cdot \frac{1}{2}}{x} + x\\ \end{array}\]

Reproduce

herbie shell --seed 2019174 
(FPCore (x y)
  :name "Linear.Quaternion:$clog from linear-1.19.1.3"

  :herbie-target
  (if (< x -1.5097698010472593e+153) (- (+ (* 0.5 (/ y x)) x)) (if (< x 5.582399551122541e+57) (sqrt (+ (* x x) y)) (+ (* 0.5 (/ y x)) x)))

  (sqrt (+ (* x x) y)))