Average Error: 11.4 → 5.2
Time: 3.7s
Precision: 64
\[\frac{a1 \cdot a2}{b1 \cdot b2}\]
\[\begin{array}{l} \mathbf{if}\;a1 \cdot a2 \le -2.12735229765193038 \cdot 10^{182}:\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \mathbf{elif}\;a1 \cdot a2 \le -1.0024754663520561 \cdot 10^{-263}:\\ \;\;\;\;\left(a1 \cdot a2\right) \cdot \frac{\frac{1}{b1}}{b2}\\ \mathbf{elif}\;a1 \cdot a2 \le 2.0414339865440529 \cdot 10^{-241}:\\ \;\;\;\;\frac{a1}{b2 \cdot \frac{b1}{a2}}\\ \mathbf{elif}\;a1 \cdot a2 \le 5.0133543486933235 \cdot 10^{213}:\\ \;\;\;\;\left(a1 \cdot a2\right) \cdot \frac{\frac{1}{b1}}{b2}\\ \mathbf{else}:\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \end{array}\]
\frac{a1 \cdot a2}{b1 \cdot b2}
\begin{array}{l}
\mathbf{if}\;a1 \cdot a2 \le -2.12735229765193038 \cdot 10^{182}:\\
\;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\

\mathbf{elif}\;a1 \cdot a2 \le -1.0024754663520561 \cdot 10^{-263}:\\
\;\;\;\;\left(a1 \cdot a2\right) \cdot \frac{\frac{1}{b1}}{b2}\\

\mathbf{elif}\;a1 \cdot a2 \le 2.0414339865440529 \cdot 10^{-241}:\\
\;\;\;\;\frac{a1}{b2 \cdot \frac{b1}{a2}}\\

\mathbf{elif}\;a1 \cdot a2 \le 5.0133543486933235 \cdot 10^{213}:\\
\;\;\;\;\left(a1 \cdot a2\right) \cdot \frac{\frac{1}{b1}}{b2}\\

\mathbf{else}:\\
\;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\

\end{array}
double f(double a1, double a2, double b1, double b2) {
        double r197933 = a1;
        double r197934 = a2;
        double r197935 = r197933 * r197934;
        double r197936 = b1;
        double r197937 = b2;
        double r197938 = r197936 * r197937;
        double r197939 = r197935 / r197938;
        return r197939;
}

double f(double a1, double a2, double b1, double b2) {
        double r197940 = a1;
        double r197941 = a2;
        double r197942 = r197940 * r197941;
        double r197943 = -2.1273522976519304e+182;
        bool r197944 = r197942 <= r197943;
        double r197945 = b2;
        double r197946 = r197941 / r197945;
        double r197947 = b1;
        double r197948 = r197946 / r197947;
        double r197949 = r197940 * r197948;
        double r197950 = -1.002475466352056e-263;
        bool r197951 = r197942 <= r197950;
        double r197952 = 1.0;
        double r197953 = r197952 / r197947;
        double r197954 = r197953 / r197945;
        double r197955 = r197942 * r197954;
        double r197956 = 2.041433986544053e-241;
        bool r197957 = r197942 <= r197956;
        double r197958 = r197947 / r197941;
        double r197959 = r197945 * r197958;
        double r197960 = r197940 / r197959;
        double r197961 = 5.0133543486933235e+213;
        bool r197962 = r197942 <= r197961;
        double r197963 = r197962 ? r197955 : r197949;
        double r197964 = r197957 ? r197960 : r197963;
        double r197965 = r197951 ? r197955 : r197964;
        double r197966 = r197944 ? r197949 : r197965;
        return r197966;
}

Error

Bits error versus a1

Bits error versus a2

Bits error versus b1

Bits error versus b2

Try it out

Your Program's Arguments

Results

Enter valid numbers for all inputs

Target

Original11.4
Target11.0
Herbie5.2
\[\frac{a1}{b1} \cdot \frac{a2}{b2}\]

Derivation

  1. Split input into 3 regimes
  2. if (* a1 a2) < -2.1273522976519304e+182 or 5.0133543486933235e+213 < (* a1 a2)

    1. Initial program 33.5

      \[\frac{a1 \cdot a2}{b1 \cdot b2}\]
    2. Using strategy rm
    3. Applied times-frac10.6

      \[\leadsto \color{blue}{\frac{a1}{b1} \cdot \frac{a2}{b2}}\]
    4. Using strategy rm
    5. Applied div-inv10.6

      \[\leadsto \color{blue}{\left(a1 \cdot \frac{1}{b1}\right)} \cdot \frac{a2}{b2}\]
    6. Applied associate-*l*9.7

      \[\leadsto \color{blue}{a1 \cdot \left(\frac{1}{b1} \cdot \frac{a2}{b2}\right)}\]
    7. Simplified9.6

      \[\leadsto a1 \cdot \color{blue}{\frac{\frac{a2}{b2}}{b1}}\]

    if -2.1273522976519304e+182 < (* a1 a2) < -1.002475466352056e-263 or 2.041433986544053e-241 < (* a1 a2) < 5.0133543486933235e+213

    1. Initial program 5.0

      \[\frac{a1 \cdot a2}{b1 \cdot b2}\]
    2. Using strategy rm
    3. Applied div-inv5.3

      \[\leadsto \color{blue}{\left(a1 \cdot a2\right) \cdot \frac{1}{b1 \cdot b2}}\]
    4. Using strategy rm
    5. Applied associate-/r*5.0

      \[\leadsto \left(a1 \cdot a2\right) \cdot \color{blue}{\frac{\frac{1}{b1}}{b2}}\]

    if -1.002475466352056e-263 < (* a1 a2) < 2.041433986544053e-241

    1. Initial program 17.1

      \[\frac{a1 \cdot a2}{b1 \cdot b2}\]
    2. Using strategy rm
    3. Applied associate-/l*7.4

      \[\leadsto \color{blue}{\frac{a1}{\frac{b1 \cdot b2}{a2}}}\]
    4. Simplified3.2

      \[\leadsto \frac{a1}{\color{blue}{b2 \cdot \frac{b1}{a2}}}\]
  3. Recombined 3 regimes into one program.
  4. Final simplification5.2

    \[\leadsto \begin{array}{l} \mathbf{if}\;a1 \cdot a2 \le -2.12735229765193038 \cdot 10^{182}:\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \mathbf{elif}\;a1 \cdot a2 \le -1.0024754663520561 \cdot 10^{-263}:\\ \;\;\;\;\left(a1 \cdot a2\right) \cdot \frac{\frac{1}{b1}}{b2}\\ \mathbf{elif}\;a1 \cdot a2 \le 2.0414339865440529 \cdot 10^{-241}:\\ \;\;\;\;\frac{a1}{b2 \cdot \frac{b1}{a2}}\\ \mathbf{elif}\;a1 \cdot a2 \le 5.0133543486933235 \cdot 10^{213}:\\ \;\;\;\;\left(a1 \cdot a2\right) \cdot \frac{\frac{1}{b1}}{b2}\\ \mathbf{else}:\\ \;\;\;\;a1 \cdot \frac{\frac{a2}{b2}}{b1}\\ \end{array}\]

Reproduce

herbie shell --seed 2020045 
(FPCore (a1 a2 b1 b2)
  :name "Quotient of products"
  :precision binary64

  :herbie-target
  (* (/ a1 b1) (/ a2 b2))

  (/ (* a1 a2) (* b1 b2)))