
(FPCore (v t) :precision binary64 (/ (- 1.0 (* 5.0 (* v v))) (* (* (* (PI) t) (sqrt (* 2.0 (- 1.0 (* 3.0 (* v v)))))) (- 1.0 (* v v)))))
\begin{array}{l}
\\
\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\mathsf{PI}\left(\right) \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)}
\end{array}
Sampling outcomes in binary64 precision:
Herbie found 10 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (v t) :precision binary64 (/ (- 1.0 (* 5.0 (* v v))) (* (* (* (PI) t) (sqrt (* 2.0 (- 1.0 (* 3.0 (* v v)))))) (- 1.0 (* v v)))))
\begin{array}{l}
\\
\frac{1 - 5 \cdot \left(v \cdot v\right)}{\left(\left(\mathsf{PI}\left(\right) \cdot t\right) \cdot \sqrt{2 \cdot \left(1 - 3 \cdot \left(v \cdot v\right)\right)}\right) \cdot \left(1 - v \cdot v\right)}
\end{array}
(FPCore (v t) :precision binary64 (/ (/ (fma (* v v) -5.0 1.0) (* (* (- 1.0 (* v v)) (PI)) (sqrt (* (fma -3.0 (* v v) 1.0) 2.0)))) t))
\begin{array}{l}
\\
\frac{\frac{\mathsf{fma}\left(v \cdot v, -5, 1\right)}{\left(\left(1 - v \cdot v\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\mathsf{fma}\left(-3, v \cdot v, 1\right) \cdot 2}}}{t}
\end{array}
Initial program 99.4%
lift-/.f64N/A
lift-*.f64N/A
associate-/r*N/A
lift--.f64N/A
flip--N/A
associate-/r/N/A
lower-*.f64N/A
Applied rewrites99.6%
Applied rewrites99.8%
(FPCore (v t) :precision binary64 (/ (/ (fma -5.0 (* v v) 1.0) (PI)) (* (- 1.0 (* v v)) (* (sqrt (fma -6.0 (* v v) 2.0)) t))))
\begin{array}{l}
\\
\frac{\frac{\mathsf{fma}\left(-5, v \cdot v, 1\right)}{\mathsf{PI}\left(\right)}}{\left(1 - v \cdot v\right) \cdot \left(\sqrt{\mathsf{fma}\left(-6, v \cdot v, 2\right)} \cdot t\right)}
\end{array}
Initial program 99.4%
lift-/.f64N/A
lift-*.f64N/A
associate-/r*N/A
lift--.f64N/A
flip--N/A
associate-/r/N/A
lower-*.f64N/A
Applied rewrites99.6%
Applied rewrites99.8%
Applied rewrites99.6%
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.6
lift-*.f64N/A
*-commutativeN/A
lower-*.f6499.6
lift-*.f64N/A
lift-fma.f64N/A
distribute-lft-inN/A
associate-*r*N/A
metadata-evalN/A
metadata-evalN/A
lift-fma.f6499.6
Applied rewrites99.6%
(FPCore (v t) :precision binary64 (/ (fma (* v v) -5.0 1.0) (* (* (- 1.0 (* v v)) (PI)) (* (sqrt (fma -6.0 (* v v) 2.0)) t))))
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(v \cdot v, -5, 1\right)}{\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 t\right)}
\end{array}
Initial program 99.4%
lift-/.f64N/A
lift-*.f64N/A
associate-/r*N/A
lift--.f64N/A
flip--N/A
associate-/r/N/A
lower-*.f64N/A
Applied rewrites99.6%
Applied rewrites99.8%
Applied rewrites99.6%
Applied rewrites99.4%
(FPCore (v t) :precision binary64 (/ (/ (fma (* v v) -2.5 1.0) (* (sqrt 2.0) (PI))) t))
\begin{array}{l}
\\
\frac{\frac{\mathsf{fma}\left(v \cdot v, -2.5, 1\right)}{\sqrt{2} \cdot \mathsf{PI}\left(\right)}}{t}
\end{array}
Initial program 99.4%
lift-/.f64N/A
lift-*.f64N/A
associate-/r*N/A
lift--.f64N/A
flip--N/A
associate-/r/N/A
lower-*.f64N/A
Applied rewrites99.6%
Applied rewrites99.8%
Taylor expanded in v around 0
Applied rewrites99.3%
(FPCore (v t) :precision binary64 (/ (fma (* v v) -2.5 1.0) (* (* (sqrt 2.0) (PI)) t)))
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(v \cdot v, -2.5, 1\right)}{\left(\sqrt{2} \cdot \mathsf{PI}\left(\right)\right) \cdot t}
\end{array}
Initial program 99.4%
Taylor expanded in v around 0
Applied rewrites98.9%
(FPCore (v t) :precision binary64 (/ (/ 1.0 (* (sqrt 2.0) (PI))) t))
\begin{array}{l}
\\
\frac{\frac{1}{\sqrt{2} \cdot \mathsf{PI}\left(\right)}}{t}
\end{array}
Initial program 99.4%
lift-/.f64N/A
lift-*.f64N/A
associate-/r*N/A
lift--.f64N/A
flip--N/A
associate-/r/N/A
lower-*.f64N/A
Applied rewrites99.6%
Applied rewrites99.8%
Taylor expanded in v around 0
Applied rewrites98.9%
(FPCore (v t) :precision binary64 (/ (/ 1.0 t) (* (sqrt 2.0) (PI))))
\begin{array}{l}
\\
\frac{\frac{1}{t}}{\sqrt{2} \cdot \mathsf{PI}\left(\right)}
\end{array}
Initial program 99.4%
Taylor expanded in v around 0
Applied rewrites98.6%
Applied rewrites98.6%
(FPCore (v t) :precision binary64 (/ 1.0 (* (* (sqrt 2.0) (PI)) t)))
\begin{array}{l}
\\
\frac{1}{\left(\sqrt{2} \cdot \mathsf{PI}\left(\right)\right) \cdot t}
\end{array}
Initial program 99.4%
Taylor expanded in v around 0
Applied rewrites98.6%
(FPCore (v t) :precision binary64 (/ 1.0 (* (* (sqrt 2.0) t) (PI))))
\begin{array}{l}
\\
\frac{1}{\left(\sqrt{2} \cdot t\right) \cdot \mathsf{PI}\left(\right)}
\end{array}
Initial program 99.4%
Taylor expanded in v around 0
Applied rewrites98.6%
Applied rewrites98.5%
(FPCore (v t) :precision binary64 (/ 1.0 (* (* t (PI)) (sqrt 2.0))))
\begin{array}{l}
\\
\frac{1}{\left(t \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{2}}
\end{array}
Initial program 99.4%
Taylor expanded in v around 0
Applied rewrites98.6%
Applied rewrites98.4%
herbie shell --seed 2025022
(FPCore (v t)
:name "Falkner and Boettcher, Equation (20:1,3)"
:precision binary64
(/ (- 1.0 (* 5.0 (* v v))) (* (* (* (PI) t) (sqrt (* 2.0 (- 1.0 (* 3.0 (* v v)))))) (- 1.0 (* v v)))))