Average Error: 7.5 → 4.3
Time: 18.3s
Precision: binary64
\[\frac{x \cdot y - \left(z \cdot 9\right) \cdot t}{a \cdot 2}\]
↓
\[\begin{array}{l} \mathbf{if}\;\left(z \cdot 9\right) \cdot t \leq -9.318790882667149 \cdot 10^{+153} \lor \neg \left(\left(z \cdot 9\right) \cdot t \leq 8.410646428049127 \cdot 10^{+305}\right):\\ \;\;\;\;\frac{x \cdot y}{a \cdot 2} - t \cdot \left(4.5 \cdot \frac{z}{a}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{x \cdot y - \left(z \cdot 9\right) \cdot t}{a}}{2}\\ \end{array}\]
\frac{x \cdot y - \left(z \cdot 9\right) \cdot t}{a \cdot 2}
↓
\begin{array}{l}
\mathbf{if}\;\left(z \cdot 9\right) \cdot t \leq -9.318790882667149 \cdot 10^{+153} \lor \neg \left(\left(z \cdot 9\right) \cdot t \leq 8.410646428049127 \cdot 10^{+305}\right):\\
\;\;\;\;\frac{x \cdot y}{a \cdot 2} - t \cdot \left(4.5 \cdot \frac{z}{a}\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{\frac{x \cdot y - \left(z \cdot 9\right) \cdot t}{a}}{2}\\

\end{array}
(FPCore (x y z t a)
 :precision binary64
 (/ (- (* x y) (* (* z 9.0) t)) (* a 2.0)))
↓
(FPCore (x y z t a)
 :precision binary64
 (if (or (<= (* (* z 9.0) t) -9.318790882667149e+153)
         (not (<= (* (* z 9.0) t) 8.410646428049127e+305)))
   (- (/ (* x y) (* a 2.0)) (* t (* 4.5 (/ z a))))
   (/ (/ (- (* x y) (* (* z 9.0) t)) a) 2.0)))
double code(double x, double y, double z, double t, double a) {
	return ((x * y) - ((z * 9.0) * t)) / (a * 2.0);
}
↓
double code(double x, double y, double z, double t, double a) {
	double tmp;
	if ((((z * 9.0) * t) <= -9.318790882667149e+153) || !(((z * 9.0) * t) <= 8.410646428049127e+305)) {
		tmp = ((x * y) / (a * 2.0)) - (t * (4.5 * (z / a)));
	} else {
		tmp = (((x * y) - ((z * 9.0) * t)) / a) / 2.0;
	}
	return tmp;
}

Error

Bits error versus x

Bits error versus y

Bits error versus z

Bits error versus t

Bits error versus a

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original7.5
Target5.8
Herbie4.3
\[\begin{array}{l} \mathbf{if}\;a < -2.090464557976709 \cdot 10^{+86}:\\ \;\;\;\;0.5 \cdot \frac{y \cdot x}{a} - 4.5 \cdot \frac{t}{\frac{a}{z}}\\ \mathbf{elif}\;a < 2.144030707833976 \cdot 10^{+99}:\\ \;\;\;\;\frac{x \cdot y - z \cdot \left(9 \cdot t\right)}{a \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;\frac{y}{a} \cdot \left(x \cdot 0.5\right) - \frac{t}{a} \cdot \left(z \cdot 4.5\right)\\ \end{array}\]

Derivation

  1. Split input into 2 regimes

  2. if (*.f64 (*.f64 z 9) t) < -9.3187908826671487e153 or 8.410646428049127e305 < (*.f64 (*.f64 z 9) t)

    1. Initial program 32.7

      \[\frac{x \cdot y - \left(z \cdot 9\right) \cdot t}{a \cdot 2}\]
    2. Using strategy rm

    3. Applied div-sub_binary64_1849732.7

      \[\leadsto \color{blue}{\frac{x \cdot y}{a \cdot 2} - \frac{\left(z \cdot 9\right) \cdot t}{a \cdot 2}}\]

    4. Simplified6.5

      \[\leadsto \frac{x \cdot y}{a \cdot 2} - \color{blue}{t \cdot \left(4.5 \cdot \frac{z}{a}\right)}\]

    if -9.3187908826671487e153 < (*.f64 (*.f64 z 9) t) < 8.410646428049127e305

    1. Initial program 4.1

      \[\frac{x \cdot y - \left(z \cdot 9\right) \cdot t}{a \cdot 2}\]
    2. Using strategy rm

    3. Applied associate-/r*_binary64_184364.1

      \[\leadsto \color{blue}{\frac{\frac{x \cdot y - \left(z \cdot 9\right) \cdot t}{a}}{2}}\]
  3. Recombined 2 regimes into one program.

  4. Final simplification4.3

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(z \cdot 9\right) \cdot t \leq -9.318790882667149 \cdot 10^{+153} \lor \neg \left(\left(z \cdot 9\right) \cdot t \leq 8.410646428049127 \cdot 10^{+305}\right):\\ \;\;\;\;\frac{x \cdot y}{a \cdot 2} - t \cdot \left(4.5 \cdot \frac{z}{a}\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{\frac{x \cdot y - \left(z \cdot 9\right) \cdot t}{a}}{2}\\ \end{array}\]

Reproduce

herbie shell --seed 2021007 
(FPCore (x y z t a)
  :name "Diagrams.Solve.Polynomial:cubForm  from diagrams-solve-0.1, I"
  :precision binary64

  :herbie-target
  (if (< a -2.090464557976709e+86) (- (* 0.5 (/ (* y x) a)) (* 4.5 (/ t (/ a z)))) (if (< a 2.144030707833976e+99) (/ (- (* x y) (* z (* 9.0 t))) (* a 2.0)) (- (* (/ y a) (* x 0.5)) (* (/ t a) (* z 4.5)))))

  (/ (- (* x y) (* (* z 9.0) t)) (* a 2.0)))