
(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 6 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 (sqrt (fma (* v v) -6.0 2.0))) (* (PI) (fma -3.0 (* v v) 3.0))))
\begin{array}{l}
\\
\frac{\frac{4}{\sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}}{\mathsf{PI}\left(\right) \cdot \mathsf{fma}\left(-3, v \cdot v, 3\right)}
\end{array}
Initial program 98.4%
Taylor expanded in v around 0
associate-*r*N/A
distribute-rgt-outN/A
lower-*.f64N/A
lower-PI.f64N/A
*-commutativeN/A
lower-fma.f64N/A
unpow2N/A
lower-*.f6498.5
Applied rewrites98.5%
lift-/.f64N/A
lift-*.f64N/A
*-commutativeN/A
associate-/r*N/A
lower-/.f64N/A
Applied rewrites100.0%
Final simplification100.0%
(FPCore (v) :precision binary64 (/ 1.3333333333333333 (* (* (- 1.0 (* v v)) (PI)) (sqrt (fma (* v v) -6.0 2.0)))))
\begin{array}{l}
\\
\frac{1.3333333333333333}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}
\end{array}
Initial program 98.4%
lift--.f64N/A
flip3--N/A
clear-numN/A
lower-/.f64N/A
clear-numN/A
flip3--N/A
lift--.f64N/A
lower-/.f6498.5
lift--.f64N/A
sub-negN/A
+-commutativeN/A
lift-*.f64N/A
distribute-lft-neg-inN/A
lower-fma.f64N/A
metadata-eval98.5
Applied rewrites98.5%
lift-/.f64N/A
lift-*.f64N/A
lift-*.f64N/A
lift-*.f64N/A
lift-PI.f64N/A
lift--.f64N/A
lift-*.f64N/A
associate-/r*N/A
lift-/.f64N/A
lift-/.f64N/A
remove-double-divN/A
lift-fma.f64N/A
+-commutativeN/A
metadata-evalN/A
cancel-sign-sub-invN/A
Applied rewrites100.0%
(FPCore (v) :precision binary64 (/ (/ 4.0 (* (PI) 3.0)) (sqrt (fma (* v v) -6.0 2.0))))
\begin{array}{l}
\\
\frac{\frac{4}{\mathsf{PI}\left(\right) \cdot 3}}{\sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)}}
\end{array}
Initial program 98.4%
Taylor expanded in v around 0
*-commutativeN/A
lower-*.f64N/A
lower-PI.f6498.0
Applied rewrites98.0%
lift-/.f64N/A
lift-*.f64N/A
associate-/r*N/A
lower-/.f64N/A
lower-/.f6499.6
lift--.f64N/A
lift-*.f64N/A
cancel-sign-sub-invN/A
metadata-evalN/A
+-commutativeN/A
Applied rewrites99.6%
Final simplification99.6%
(FPCore (v) :precision binary64 (/ 1.3333333333333333 (* (sqrt (fma -6.0 (* v v) 2.0)) (PI))))
\begin{array}{l}
\\
\frac{1.3333333333333333}{\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot \mathsf{PI}\left(\right)}
\end{array}
Initial program 98.4%
Applied rewrites99.6%
Taylor expanded in v around 0
lower-PI.f6499.6
Applied rewrites99.6%
Final simplification99.6%
(FPCore (v) :precision binary64 (/ 1.3333333333333333 (* (sqrt 2.0) (PI))))
\begin{array}{l}
\\
\frac{1.3333333333333333}{\sqrt{2} \cdot \mathsf{PI}\left(\right)}
\end{array}
Initial program 98.4%
Applied rewrites99.6%
Taylor expanded in v around 0
*-commutativeN/A
lower-*.f64N/A
lower-sqrt.f64N/A
lower-PI.f6499.5
Applied rewrites99.5%
(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 98.4%
Taylor expanded in v around 0
*-commutativeN/A
lower-*.f64N/A
lower-/.f64N/A
lower-sqrt.f64N/A
lower-PI.f6498.0
Applied rewrites98.0%
herbie shell --seed 2024271
(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)))))))