Falkner and Boettcher, Equation (22+)

Percentage Accurate: 98.5% → 100.0%
Time: 4.7s
Alternatives: 5
Speedup: 2.1×

Specification

?
\[\begin{array}{l} \\ \frac{4}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \end{array} \]
(FPCore (v)
 :precision binary64
 (/ 4.0 (* (* (* 3.0 (PI)) (- 1.0 (* v v))) (sqrt (- 2.0 (* 6.0 (* v v)))))))
\begin{array}{l}

\\
\frac{4}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 5 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 98.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{4}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \end{array} \]
(FPCore (v)
 :precision binary64
 (/ 4.0 (* (* (* 3.0 (PI)) (- 1.0 (* v v))) (sqrt (- 2.0 (* 6.0 (* v v)))))))
\begin{array}{l}

\\
\frac{4}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}
\end{array}

Alternative 1: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\frac{1.3333333333333333}{\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \end{array} \]
(FPCore (v)
 :precision binary64
 (/
  (/ 1.3333333333333333 (* (- 1.0 (* v v)) (PI)))
  (sqrt (fma -6.0 (* v v) 2.0))))
\begin{array}{l}

\\
\frac{\frac{1.3333333333333333}{\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}
\end{array}
Derivation
  1. Initial program 98.4%

    \[\frac{4}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{4}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    2. lift-*.f64N/A

      \[\leadsto \frac{4}{\color{blue}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    3. associate-/r*N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    4. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{\frac{4}{\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    5. lift-*.f64N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    6. lift-*.f64N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{\left(3 \cdot \mathsf{PI}\left(\right)\right)} \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    7. associate-*l*N/A

      \[\leadsto \frac{\frac{4}{\color{blue}{3 \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    8. associate-/r*N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{4}{3}}{\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    9. lower-/.f64N/A

      \[\leadsto \frac{\color{blue}{\frac{\frac{4}{3}}{\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    10. metadata-evalN/A

      \[\leadsto \frac{\frac{\color{blue}{\frac{4}{3}}}{\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    11. *-commutativeN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\color{blue}{\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    12. lower-*.f64100.0

      \[\leadsto \frac{\frac{1.3333333333333333}{\color{blue}{\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)}}}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    13. lift--.f64N/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)}}{\sqrt{\color{blue}{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    14. lift-*.f64N/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)}}{\sqrt{2 - \color{blue}{6 \cdot \left(v \cdot v\right)}}} \]
    15. fp-cancel-sub-sign-invN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)}}{\sqrt{\color{blue}{2 + \left(\mathsf{neg}\left(6\right)\right) \cdot \left(v \cdot v\right)}}} \]
    16. +-commutativeN/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)}}{\sqrt{\color{blue}{\left(\mathsf{neg}\left(6\right)\right) \cdot \left(v \cdot v\right) + 2}}} \]
    17. lower-fma.f64N/A

      \[\leadsto \frac{\frac{\frac{4}{3}}{\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)}}{\sqrt{\color{blue}{\mathsf{fma}\left(\mathsf{neg}\left(6\right), v \cdot v, 2\right)}}} \]
    18. metadata-eval100.0

      \[\leadsto \frac{\frac{1.3333333333333333}{\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)}}{\sqrt{\mathsf{fma}\left(\color{blue}{-6}, v \cdot v, 2\right)}} \]
  4. Applied rewrites100.0%

    \[\leadsto \color{blue}{\frac{\frac{1.3333333333333333}{\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
  5. Add Preprocessing

Alternative 2: 100.0% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \frac{4}{\mathsf{PI}\left(\right) \cdot \left(\mathsf{fma}\left(-3 \cdot v, v, 3\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\right)} \end{array} \]
(FPCore (v)
 :precision binary64
 (/ 4.0 (* (PI) (* (fma (* -3.0 v) v 3.0) (sqrt (fma -6.0 (* v v) 2.0))))))
\begin{array}{l}

\\
\frac{4}{\mathsf{PI}\left(\right) \cdot \left(\mathsf{fma}\left(-3 \cdot v, v, 3\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\right)}
\end{array}
Derivation
  1. Initial program 98.4%

    \[\frac{4}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \frac{4}{\color{blue}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    2. *-commutativeN/A

      \[\leadsto \frac{4}{\color{blue}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot \left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right)}} \]
    3. lift-*.f64N/A

      \[\leadsto \frac{4}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot \color{blue}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right)}} \]
    4. lift-*.f64N/A

      \[\leadsto \frac{4}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot \left(\color{blue}{\left(3 \cdot \mathsf{PI}\left(\right)\right)} \cdot \left(1 - v \cdot v\right)\right)} \]
    5. associate-*l*N/A

      \[\leadsto \frac{4}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot \color{blue}{\left(3 \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)\right)}} \]
    6. associate-*r*N/A

      \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)}} \]
    7. lower-*.f64N/A

      \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)}} \]
    8. lower-*.f64N/A

      \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot 3\right)} \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
    9. lift--.f64N/A

      \[\leadsto \frac{4}{\left(\sqrt{\color{blue}{2 - 6 \cdot \left(v \cdot v\right)}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
    10. lift-*.f64N/A

      \[\leadsto \frac{4}{\left(\sqrt{2 - \color{blue}{6 \cdot \left(v \cdot v\right)}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
    11. fp-cancel-sub-sign-invN/A

      \[\leadsto \frac{4}{\left(\sqrt{\color{blue}{2 + \left(\mathsf{neg}\left(6\right)\right) \cdot \left(v \cdot v\right)}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
    12. +-commutativeN/A

      \[\leadsto \frac{4}{\left(\sqrt{\color{blue}{\left(\mathsf{neg}\left(6\right)\right) \cdot \left(v \cdot v\right) + 2}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
    13. lower-fma.f64N/A

      \[\leadsto \frac{4}{\left(\sqrt{\color{blue}{\mathsf{fma}\left(\mathsf{neg}\left(6\right), v \cdot v, 2\right)}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
    14. metadata-evalN/A

      \[\leadsto \frac{4}{\left(\sqrt{\mathsf{fma}\left(\color{blue}{-6}, v \cdot v, 2\right)} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
    15. *-commutativeN/A

      \[\leadsto \frac{4}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \color{blue}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right)}} \]
    16. lower-*.f64100.0

      \[\leadsto \frac{4}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \color{blue}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right)}} \]
  4. Applied rewrites100.0%

    \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right)}} \]
  5. Step-by-step derivation
    1. lift-*.f64N/A

      \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right)}} \]
    2. *-commutativeN/A

      \[\leadsto \frac{4}{\color{blue}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right)}} \]
    3. lift-*.f64N/A

      \[\leadsto \frac{4}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \color{blue}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right)}} \]
    4. *-commutativeN/A

      \[\leadsto \frac{4}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \color{blue}{\left(3 \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\right)}} \]
    5. lift-fma.f64N/A

      \[\leadsto \frac{4}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \left(3 \cdot \sqrt{\color{blue}{-6 \cdot \left(v \cdot v\right) + 2}}\right)} \]
    6. +-commutativeN/A

      \[\leadsto \frac{4}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \left(3 \cdot \sqrt{\color{blue}{2 + -6 \cdot \left(v \cdot v\right)}}\right)} \]
    7. metadata-evalN/A

      \[\leadsto \frac{4}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \left(3 \cdot \sqrt{2 + \color{blue}{\left(\mathsf{neg}\left(6\right)\right)} \cdot \left(v \cdot v\right)}\right)} \]
    8. fp-cancel-sub-sign-invN/A

      \[\leadsto \frac{4}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \left(3 \cdot \sqrt{\color{blue}{2 - 6 \cdot \left(v \cdot v\right)}}\right)} \]
    9. lift-*.f64N/A

      \[\leadsto \frac{4}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \left(3 \cdot \sqrt{2 - \color{blue}{6 \cdot \left(v \cdot v\right)}}\right)} \]
    10. lift--.f64N/A

      \[\leadsto \frac{4}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \left(3 \cdot \sqrt{\color{blue}{2 - 6 \cdot \left(v \cdot v\right)}}\right)} \]
    11. associate-*r*N/A

      \[\leadsto \frac{4}{\color{blue}{\left(\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right) \cdot 3\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
    12. lift-*.f64N/A

      \[\leadsto \frac{4}{\left(\color{blue}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right)} \cdot 3\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    13. *-commutativeN/A

      \[\leadsto \frac{4}{\left(\color{blue}{\left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \cdot 3\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    14. associate-*r*N/A

      \[\leadsto \frac{4}{\color{blue}{\left(\mathsf{PI}\left(\right) \cdot \left(\left(1 - v \cdot v\right) \cdot 3\right)\right)} \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    15. lift-*.f64N/A

      \[\leadsto \frac{4}{\left(\mathsf{PI}\left(\right) \cdot \color{blue}{\left(\left(1 - v \cdot v\right) \cdot 3\right)}\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
  6. Applied rewrites100.0%

    \[\leadsto \frac{4}{\color{blue}{\mathsf{PI}\left(\right) \cdot \left(\left(3 \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\right)}} \]
  7. Taylor expanded in v around 0

    \[\leadsto \frac{4}{\mathsf{PI}\left(\right) \cdot \left(\color{blue}{\left(3 + -3 \cdot {v}^{2}\right)} \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\right)} \]
  8. Step-by-step derivation
    1. Applied rewrites100.0%

      \[\leadsto \frac{4}{\mathsf{PI}\left(\right) \cdot \left(\color{blue}{\mathsf{fma}\left(-3 \cdot v, v, 3\right)} \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\right)} \]
    2. Add Preprocessing

    Alternative 3: 98.9% accurate, 1.2× speedup?

    \[\begin{array}{l} \\ \frac{\frac{4}{\mathsf{PI}\left(\right)}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3} \end{array} \]
    (FPCore (v)
     :precision binary64
     (/ (/ 4.0 (PI)) (* (sqrt (fma -6.0 (* v v) 2.0)) 3.0)))
    \begin{array}{l}
    
    \\
    \frac{\frac{4}{\mathsf{PI}\left(\right)}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3}
    \end{array}
    
    Derivation
    1. Initial program 98.4%

      \[\frac{4}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{4}{\color{blue}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
      2. *-commutativeN/A

        \[\leadsto \frac{4}{\color{blue}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot \left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right)}} \]
      3. lift-*.f64N/A

        \[\leadsto \frac{4}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot \color{blue}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right)}} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{4}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot \left(\color{blue}{\left(3 \cdot \mathsf{PI}\left(\right)\right)} \cdot \left(1 - v \cdot v\right)\right)} \]
      5. associate-*l*N/A

        \[\leadsto \frac{4}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot \color{blue}{\left(3 \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)\right)}} \]
      6. associate-*r*N/A

        \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)}} \]
      7. lower-*.f64N/A

        \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)}} \]
      8. lower-*.f64N/A

        \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot 3\right)} \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
      9. lift--.f64N/A

        \[\leadsto \frac{4}{\left(\sqrt{\color{blue}{2 - 6 \cdot \left(v \cdot v\right)}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
      10. lift-*.f64N/A

        \[\leadsto \frac{4}{\left(\sqrt{2 - \color{blue}{6 \cdot \left(v \cdot v\right)}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
      11. fp-cancel-sub-sign-invN/A

        \[\leadsto \frac{4}{\left(\sqrt{\color{blue}{2 + \left(\mathsf{neg}\left(6\right)\right) \cdot \left(v \cdot v\right)}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
      12. +-commutativeN/A

        \[\leadsto \frac{4}{\left(\sqrt{\color{blue}{\left(\mathsf{neg}\left(6\right)\right) \cdot \left(v \cdot v\right) + 2}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
      13. lower-fma.f64N/A

        \[\leadsto \frac{4}{\left(\sqrt{\color{blue}{\mathsf{fma}\left(\mathsf{neg}\left(6\right), v \cdot v, 2\right)}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
      14. metadata-evalN/A

        \[\leadsto \frac{4}{\left(\sqrt{\mathsf{fma}\left(\color{blue}{-6}, v \cdot v, 2\right)} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
      15. *-commutativeN/A

        \[\leadsto \frac{4}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \color{blue}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right)}} \]
      16. lower-*.f64100.0

        \[\leadsto \frac{4}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \color{blue}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right)}} \]
    4. Applied rewrites100.0%

      \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right)}} \]
    5. Taylor expanded in v around 0

      \[\leadsto \frac{4}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \color{blue}{\mathsf{PI}\left(\right)}} \]
    6. Step-by-step derivation
      1. Applied rewrites98.7%

        \[\leadsto \frac{4}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \color{blue}{\mathsf{PI}\left(\right)}} \]
      2. Step-by-step derivation
        1. lift-/.f64N/A

          \[\leadsto \color{blue}{\frac{4}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \mathsf{PI}\left(\right)}} \]
        2. lift-*.f64N/A

          \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \mathsf{PI}\left(\right)}} \]
        3. *-commutativeN/A

          \[\leadsto \frac{4}{\color{blue}{\mathsf{PI}\left(\right) \cdot \left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right)}} \]
        4. associate-/r*N/A

          \[\leadsto \color{blue}{\frac{\frac{4}{\mathsf{PI}\left(\right)}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3}} \]
        5. lower-/.f64N/A

          \[\leadsto \color{blue}{\frac{\frac{4}{\mathsf{PI}\left(\right)}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3}} \]
        6. lower-/.f6498.7

          \[\leadsto \frac{\color{blue}{\frac{4}{\mathsf{PI}\left(\right)}}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3} \]
      3. Applied rewrites98.7%

        \[\leadsto \color{blue}{\frac{\frac{4}{\mathsf{PI}\left(\right)}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3}} \]
      4. Add Preprocessing

      Alternative 4: 98.9% accurate, 1.5× speedup?

      \[\begin{array}{l} \\ \frac{1.3333333333333333}{\mathsf{PI}\left(\right) \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}} \end{array} \]
      (FPCore (v)
       :precision binary64
       (/ 1.3333333333333333 (* (PI) (sqrt (fma (* v v) -6.0 2.0)))))
      \begin{array}{l}
      
      \\
      \frac{1.3333333333333333}{\mathsf{PI}\left(\right) \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}
      \end{array}
      
      Derivation
      1. Initial program 98.4%

        \[\frac{4}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-*.f64N/A

          \[\leadsto \frac{4}{\color{blue}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}} \]
        2. *-commutativeN/A

          \[\leadsto \frac{4}{\color{blue}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot \left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right)}} \]
        3. lift-*.f64N/A

          \[\leadsto \frac{4}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot \color{blue}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right)}} \]
        4. lift-*.f64N/A

          \[\leadsto \frac{4}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot \left(\color{blue}{\left(3 \cdot \mathsf{PI}\left(\right)\right)} \cdot \left(1 - v \cdot v\right)\right)} \]
        5. associate-*l*N/A

          \[\leadsto \frac{4}{\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot \color{blue}{\left(3 \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)\right)}} \]
        6. associate-*r*N/A

          \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)}} \]
        7. lower-*.f64N/A

          \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)}} \]
        8. lower-*.f64N/A

          \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{2 - 6 \cdot \left(v \cdot v\right)} \cdot 3\right)} \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
        9. lift--.f64N/A

          \[\leadsto \frac{4}{\left(\sqrt{\color{blue}{2 - 6 \cdot \left(v \cdot v\right)}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
        10. lift-*.f64N/A

          \[\leadsto \frac{4}{\left(\sqrt{2 - \color{blue}{6 \cdot \left(v \cdot v\right)}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
        11. fp-cancel-sub-sign-invN/A

          \[\leadsto \frac{4}{\left(\sqrt{\color{blue}{2 + \left(\mathsf{neg}\left(6\right)\right) \cdot \left(v \cdot v\right)}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
        12. +-commutativeN/A

          \[\leadsto \frac{4}{\left(\sqrt{\color{blue}{\left(\mathsf{neg}\left(6\right)\right) \cdot \left(v \cdot v\right) + 2}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
        13. lower-fma.f64N/A

          \[\leadsto \frac{4}{\left(\sqrt{\color{blue}{\mathsf{fma}\left(\mathsf{neg}\left(6\right), v \cdot v, 2\right)}} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
        14. metadata-evalN/A

          \[\leadsto \frac{4}{\left(\sqrt{\mathsf{fma}\left(\color{blue}{-6}, v \cdot v, 2\right)} \cdot 3\right) \cdot \left(\mathsf{PI}\left(\right) \cdot \left(1 - v \cdot v\right)\right)} \]
        15. *-commutativeN/A

          \[\leadsto \frac{4}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \color{blue}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right)}} \]
        16. lower-*.f64100.0

          \[\leadsto \frac{4}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \color{blue}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right)}} \]
      4. Applied rewrites100.0%

        \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right)}} \]
      5. Taylor expanded in v around 0

        \[\leadsto \frac{4}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \color{blue}{\mathsf{PI}\left(\right)}} \]
      6. Step-by-step derivation
        1. Applied rewrites98.7%

          \[\leadsto \frac{4}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \color{blue}{\mathsf{PI}\left(\right)}} \]
        2. Step-by-step derivation
          1. lift-*.f64N/A

            \[\leadsto \frac{4}{\color{blue}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right) \cdot \mathsf{PI}\left(\right)}} \]
          2. *-commutativeN/A

            \[\leadsto \frac{4}{\color{blue}{\mathsf{PI}\left(\right) \cdot \left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right)}} \]
          3. lift-*.f64N/A

            \[\leadsto \frac{4}{\mathsf{PI}\left(\right) \cdot \color{blue}{\left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot 3\right)}} \]
          4. associate-*r*N/A

            \[\leadsto \frac{4}{\color{blue}{\left(\mathsf{PI}\left(\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\right) \cdot 3}} \]
          5. lower-*.f64N/A

            \[\leadsto \frac{4}{\color{blue}{\left(\mathsf{PI}\left(\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\right) \cdot 3}} \]
          6. lower-*.f6497.2

            \[\leadsto \frac{4}{\color{blue}{\left(\mathsf{PI}\left(\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\right)} \cdot 3} \]
        3. Applied rewrites97.2%

          \[\leadsto \frac{4}{\color{blue}{\left(\mathsf{PI}\left(\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\right) \cdot 3}} \]
        4. Step-by-step derivation
          1. lift-/.f64N/A

            \[\leadsto \color{blue}{\frac{4}{\left(\mathsf{PI}\left(\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\right) \cdot 3}} \]
          2. lift-*.f64N/A

            \[\leadsto \frac{4}{\color{blue}{\left(\mathsf{PI}\left(\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\right) \cdot 3}} \]
          3. *-commutativeN/A

            \[\leadsto \frac{4}{\color{blue}{3 \cdot \left(\mathsf{PI}\left(\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\right)}} \]
          4. associate-/r*N/A

            \[\leadsto \color{blue}{\frac{\frac{4}{3}}{\mathsf{PI}\left(\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
          5. lower-/.f64N/A

            \[\leadsto \color{blue}{\frac{\frac{4}{3}}{\mathsf{PI}\left(\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}} \]
          6. metadata-eval98.7

            \[\leadsto \frac{\color{blue}{1.3333333333333333}}{\mathsf{PI}\left(\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}} \]
          7. lift-fma.f64N/A

            \[\leadsto \frac{\frac{4}{3}}{\mathsf{PI}\left(\right) \cdot \sqrt{\color{blue}{-6 \cdot \left(v \cdot v\right) + 2}}} \]
          8. *-commutativeN/A

            \[\leadsto \frac{\frac{4}{3}}{\mathsf{PI}\left(\right) \cdot \sqrt{\color{blue}{\left(v \cdot v\right) \cdot -6} + 2}} \]
          9. lower-fma.f6498.7

            \[\leadsto \frac{1.3333333333333333}{\mathsf{PI}\left(\right) \cdot \sqrt{\color{blue}{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}} \]
        5. Applied rewrites98.7%

          \[\leadsto \color{blue}{\frac{1.3333333333333333}{\mathsf{PI}\left(\right) \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}} \]
        6. Add Preprocessing

        Alternative 5: 98.9% accurate, 2.1× speedup?

        \[\begin{array}{l} \\ \sqrt{0.5} \cdot \frac{1.3333333333333333}{\mathsf{PI}\left(\right)} \end{array} \]
        (FPCore (v) :precision binary64 (* (sqrt 0.5) (/ 1.3333333333333333 (PI))))
        \begin{array}{l}
        
        \\
        \sqrt{0.5} \cdot \frac{1.3333333333333333}{\mathsf{PI}\left(\right)}
        \end{array}
        
        Derivation
        1. Initial program 98.4%

          \[\frac{4}{\left(\left(3 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}} \]
        2. Add Preprocessing
        3. Taylor expanded in v around 0

          \[\leadsto \color{blue}{\frac{4}{3} \cdot \frac{\sqrt{\frac{1}{2}}}{\mathsf{PI}\left(\right)}} \]
        4. Step-by-step derivation
          1. Applied rewrites97.1%

            \[\leadsto \color{blue}{\frac{\sqrt{0.5}}{\mathsf{PI}\left(\right)} \cdot 1.3333333333333333} \]
          2. Step-by-step derivation
            1. Applied rewrites98.7%

              \[\leadsto \sqrt{0.5} \cdot \color{blue}{\frac{1.3333333333333333}{\mathsf{PI}\left(\right)}} \]
            2. Add Preprocessing

            Reproduce

            ?
            herbie shell --seed 2025025 
            (FPCore (v)
              :name "Falkner and Boettcher, Equation (22+)"
              :precision binary64
              (/ 4.0 (* (* (* 3.0 (PI)) (- 1.0 (* v v))) (sqrt (- 2.0 (* 6.0 (* v v)))))))