
(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 7 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 (let* ((t_0 (sqrt (fma -6.0 (* v v) 2.0)))) (/ 4.0 (fma (* 3.0 t_0) (PI) (* (* (- v) (* (* (PI) 3.0) v)) t_0)))))
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\\
\frac{4}{\mathsf{fma}\left(3 \cdot t\_0, \mathsf{PI}\left(\right), \left(\left(-v\right) \cdot \left(\left(\mathsf{PI}\left(\right) \cdot 3\right) \cdot v\right)\right) \cdot t\_0\right)}
\end{array}
\end{array}
Initial program 98.5%
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
lift--.f64N/A
sub-negN/A
distribute-lft-inN/A
*-rgt-identityN/A
distribute-rgt-inN/A
*-commutativeN/A
lift-*.f64N/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites100.0%
Final simplification100.0%
(FPCore (v) :precision binary64 (/ 1.3333333333333333 (* (* (- (PI)) (sqrt (fma -6.0 (* v v) 2.0))) (fma v v -1.0))))
\begin{array}{l}
\\
\frac{1.3333333333333333}{\left(\left(-\mathsf{PI}\left(\right)\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}\right) \cdot \mathsf{fma}\left(v, v, -1\right)}
\end{array}
Initial program 98.5%
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
lift--.f64N/A
sub-negN/A
distribute-lft-inN/A
*-rgt-identityN/A
distribute-rgt-inN/A
*-commutativeN/A
lift-*.f64N/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites100.0%
Applied rewrites100.0%
remove-double-negN/A
lift-*.f64N/A
lift-*.f64N/A
associate-*l*N/A
distribute-rgt-neg-inN/A
distribute-lft-neg-inN/A
lift-fma.f64N/A
distribute-neg-inN/A
distribute-rgt-neg-inN/A
lift-neg.f64N/A
sqr-negN/A
lift-*.f64N/A
lift-*.f64N/A
metadata-evalN/A
lift-fma.f64N/A
lower-*.f64N/A
Applied rewrites100.0%
Final simplification100.0%
(FPCore (v) :precision binary64 (/ -1.3333333333333333 (* (* (fma v v -1.0) (PI)) (sqrt (fma -6.0 (* v v) 2.0)))))
\begin{array}{l}
\\
\frac{-1.3333333333333333}{\left(\mathsf{fma}\left(v, v, -1\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}
\end{array}
Initial program 98.5%
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
lift--.f64N/A
sub-negN/A
distribute-lft-inN/A
*-rgt-identityN/A
distribute-rgt-inN/A
*-commutativeN/A
lift-*.f64N/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites100.0%
Applied rewrites100.0%
lift-/.f64N/A
frac-2negN/A
lower-/.f64N/A
metadata-evalN/A
lift-*.f64N/A
distribute-lft-neg-inN/A
Applied rewrites100.0%
(FPCore (v) :precision binary64 (/ 4.0 (* (PI) (* (sqrt (fma (* v v) -6.0 2.0)) 3.0))))
\begin{array}{l}
\\
\frac{4}{\mathsf{PI}\left(\right) \cdot \left(\sqrt{\mathsf{fma}\left(v \cdot v, -6, 2\right)} \cdot 3\right)}
\end{array}
Initial program 98.5%
lift-*.f64N/A
*-commutativeN/A
lift-*.f64N/A
lift--.f64N/A
sub-negN/A
distribute-lft-inN/A
*-rgt-identityN/A
distribute-rgt-inN/A
*-commutativeN/A
lift-*.f64N/A
associate-*r*N/A
lower-fma.f64N/A
Applied rewrites100.0%
Applied rewrites100.0%
Taylor expanded in v around 0
lower-PI.f6499.0
Applied rewrites99.0%
Final simplification99.0%
(FPCore (v) :precision binary64 (/ 1.3333333333333333 (* (PI) (sqrt (fma -6.0 (* v v) 2.0)))))
\begin{array}{l}
\\
\frac{1.3333333333333333}{\mathsf{PI}\left(\right) \cdot \sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)}}
\end{array}
Initial program 98.5%
Applied rewrites98.9%
Taylor expanded in v around 0
lower-PI.f6499.0
Applied rewrites99.0%
(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 98.5%
Applied rewrites98.9%
Taylor expanded in v around 0
*-commutativeN/A
lower-*.f64N/A
lower-sqrt.f64N/A
lower-PI.f6498.9
Applied rewrites98.9%
(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
lower-PI.f6497.4
Applied rewrites97.4%
herbie shell --seed 2024250
(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)))))))