
(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:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(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}
(FPCore (v) :precision binary64 (/ (/ 4.0 (* (- 1.0 (* v v)) (* (PI) 3.0))) (sqrt (fma -6.0 (* v v) 2.0))))
\begin{array}{l}
\\
\frac{\frac{4}{\left(1 - v \cdot v\right) \cdot \left(\mathsf{PI}\left(\right) \cdot 3\right)}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}
\end{array}
Initial program 98.5%
lift-/.f64N/A
lift-*.f64N/A
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
lift--.f64N/A
lift-*.f64N/A
lift-sqrt.f64N/A
lift--.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-/r*N/A
lower-/.f64N/A
Applied rewrites100.0%
(FPCore (v) :precision binary64 (/ (/ 4.0 (* (PI) 3.0)) (sqrt (fma (* -6.0 v) v 2.0))))
\begin{array}{l}
\\
\frac{\frac{4}{\mathsf{PI}\left(\right) \cdot 3}}{\sqrt{\mathsf{fma}\left(-6 \cdot v, v, 2\right)}}
\end{array}
Initial program 98.5%
Taylor expanded in v around 0
*-commutativeN/A
lower-*.f64N/A
lift-PI.f6497.7
Applied rewrites97.7%
lift-/.f64N/A
lift-*.f64N/A
lift-sqrt.f64N/A
lift--.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-/r*N/A
pow2N/A
metadata-evalN/A
fp-cancel-sign-sub-invN/A
pow2N/A
lift-*.f64N/A
Applied rewrites99.2%
(FPCore (v) :precision binary64 (/ (/ 1.3333333333333333 (PI)) (sqrt (fma -6.0 (* v v) 2.0))))
\begin{array}{l}
\\
\frac{\frac{1.3333333333333333}{\mathsf{PI}\left(\right)}}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}
\end{array}
Initial program 98.5%
lift-/.f64N/A
lift-*.f64N/A
lift-*.f64N/A
lift-PI.f64N/A
lift-*.f64N/A
lift--.f64N/A
lift-*.f64N/A
lift-sqrt.f64N/A
lift--.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-/r*N/A
lower-/.f64N/A
Applied rewrites100.0%
Taylor expanded in v around 0
lower-/.f64N/A
lift-PI.f6499.2
Applied rewrites99.2%
(FPCore (v) :precision binary64 (/ (/ 1.3333333333333333 (PI)) (sqrt 2.0)))
\begin{array}{l}
\\
\frac{\frac{1.3333333333333333}{\mathsf{PI}\left(\right)}}{\sqrt{2}}
\end{array}
Initial program 98.5%
Taylor expanded in v around 0
*-commutativeN/A
lower-*.f64N/A
lift-PI.f6497.7
Applied rewrites97.7%
lift-/.f64N/A
lift-*.f64N/A
lift-sqrt.f64N/A
lift--.f64N/A
lift-*.f64N/A
lift-*.f64N/A
associate-/r*N/A
pow2N/A
metadata-evalN/A
fp-cancel-sign-sub-invN/A
pow2N/A
lift-*.f64N/A
Applied rewrites99.2%
Taylor expanded in v around 0
associate-*r*99.2
Applied rewrites99.2%
Taylor expanded in v around 0
lower-/.f64N/A
lift-PI.f6499.2
Applied rewrites99.2%
(FPCore (v) :precision binary64 (* (/ (sqrt 0.5) (PI)) 1.3333333333333333))
\begin{array}{l}
\\
\frac{\sqrt{0.5}}{\mathsf{PI}\left(\right)} \cdot 1.3333333333333333
\end{array}
Initial program 98.5%
Taylor expanded in v around 0
*-commutativeN/A
lower-*.f64N/A
lower-/.f64N/A
lower-sqrt.f64N/A
lift-PI.f6497.6
Applied rewrites97.6%
herbie shell --seed 2025050
(FPCore (v)
:name "Falkner and Boettcher, Equation (22+)"
:precision binary64
:pre (TRUE)
(/ 4.0 (* (* (* 3.0 (PI)) (- 1.0 (* v v))) (sqrt (- 2.0 (* 6.0 (* v v)))))))