
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (- (* alpha alpha) 1.0)))
(/
t_0
(* (* (PI) (log (* alpha alpha))) (+ 1.0 (* (* t_0 cosTheta) cosTheta))))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \alpha \cdot \alpha - 1\\
\frac{t\_0}{\left(\mathsf{PI}\left(\right) \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \left(1 + \left(t\_0 \cdot cosTheta\right) \cdot cosTheta\right)}
\end{array}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 12 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (- (* alpha alpha) 1.0)))
(/
t_0
(* (* (PI) (log (* alpha alpha))) (+ 1.0 (* (* t_0 cosTheta) cosTheta))))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \alpha \cdot \alpha - 1\\
\frac{t\_0}{\left(\mathsf{PI}\left(\right) \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \left(1 + \left(t\_0 \cdot cosTheta\right) \cdot cosTheta\right)}
\end{array}
\end{array}
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (- (* alpha alpha) 1.0)))
(/
t_0
(*
(log (pow (* alpha alpha) (PI)))
(+ 1.0 (* (* t_0 cosTheta) cosTheta))))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \alpha \cdot \alpha - 1\\
\frac{t\_0}{\log \left({\left(\alpha \cdot \alpha\right)}^{\mathsf{PI}\left(\right)}\right) \cdot \left(1 + \left(t\_0 \cdot cosTheta\right) \cdot cosTheta\right)}
\end{array}
\end{array}
Initial program 98.4%
log-pow-revN/A
pow2N/A
lower-log.f32N/A
lower-pow.f32N/A
pow2N/A
lower-*.f32N/A
lower-PI.f3298.7
Applied rewrites98.7%
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (- (* alpha alpha) 1.0)))
(/
(/ (/ t_0 (PI)) (log (* alpha alpha)))
(+ (* (* cosTheta cosTheta) t_0) 1.0))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \alpha \cdot \alpha - 1\\
\frac{\frac{\frac{t\_0}{\mathsf{PI}\left(\right)}}{\log \left(\alpha \cdot \alpha\right)}}{\left(cosTheta \cdot cosTheta\right) \cdot t\_0 + 1}
\end{array}
\end{array}
Initial program 98.4%
associate-/r*N/A
pow2N/A
pow2N/A
lower-/.f32N/A
associate-/r*N/A
lower-/.f32N/A
lower-/.f32N/A
lower--.f32N/A
pow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-log.f32N/A
pow2N/A
lower-*.f32N/A
+-commutativeN/A
Applied rewrites98.5%
pow2N/A
pow2N/A
lower-+.f32N/A
lower-*.f32N/A
pow2N/A
lower-*.f32N/A
lower--.f32N/A
pow2N/A
lower-*.f3298.5
Applied rewrites98.5%
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (- (* alpha alpha) 1.0)))
(/
(/ (/ t_0 (PI)) (log (* alpha alpha)))
(fma (* cosTheta cosTheta) t_0 1.0))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \alpha \cdot \alpha - 1\\
\frac{\frac{\frac{t\_0}{\mathsf{PI}\left(\right)}}{\log \left(\alpha \cdot \alpha\right)}}{\mathsf{fma}\left(cosTheta \cdot cosTheta, t\_0, 1\right)}
\end{array}
\end{array}
Initial program 98.4%
associate-/r*N/A
pow2N/A
pow2N/A
lower-/.f32N/A
associate-/r*N/A
lower-/.f32N/A
lower-/.f32N/A
lower--.f32N/A
pow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-log.f32N/A
pow2N/A
lower-*.f32N/A
+-commutativeN/A
Applied rewrites98.5%
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (- (* alpha alpha) 1.0)))
(/
t_0
(* (* (PI) (log (* alpha alpha))) (fma t_0 (* cosTheta cosTheta) 1.0)))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \alpha \cdot \alpha - 1\\
\frac{t\_0}{\left(\mathsf{PI}\left(\right) \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \mathsf{fma}\left(t\_0, cosTheta \cdot cosTheta, 1\right)}
\end{array}
\end{array}
Initial program 98.4%
+-commutativeN/A
associate-*l*N/A
pow2N/A
unpow2N/A
lower-fma.f32N/A
lower--.f32N/A
pow2N/A
lower-*.f32N/A
unpow2N/A
lower-*.f3298.4
Applied rewrites98.4%
(FPCore (cosTheta alpha)
:precision binary32
(let* ((t_0 (- (* alpha alpha) 1.0)))
(/
t_0
(* (PI) (* (log (* alpha alpha)) (fma (* cosTheta cosTheta) t_0 1.0))))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \alpha \cdot \alpha - 1\\
\frac{t\_0}{\mathsf{PI}\left(\right) \cdot \left(\log \left(\alpha \cdot \alpha\right) \cdot \mathsf{fma}\left(cosTheta \cdot cosTheta, t\_0, 1\right)\right)}
\end{array}
\end{array}
Initial program 98.4%
pow2N/A
associate-*l*N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-*.f32N/A
lower-log.f32N/A
pow2N/A
lower-*.f32N/A
+-commutativeN/A
associate-*l*N/A
pow2N/A
unpow2N/A
*-commutativeN/A
lower-fma.f32N/A
unpow2N/A
lower-*.f32N/A
lower--.f32N/A
pow2N/A
lower-*.f3298.4
Applied rewrites98.4%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* (* (PI) (log (* alpha alpha))) (fma cosTheta (- cosTheta) 1.0))))
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\left(\mathsf{PI}\left(\right) \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \mathsf{fma}\left(cosTheta, -cosTheta, 1\right)}
\end{array}
Initial program 98.4%
Taylor expanded in alpha around inf
*-commutativeN/A
lower-*.f32N/A
Applied rewrites98.3%
Taylor expanded in alpha around 0
*-commutativeN/A
pow2N/A
+-commutativeN/A
associate-*l*N/A
*-commutativeN/A
lower-fma.f32N/A
mul-1-negN/A
lower-neg.f3297.4
Applied rewrites97.4%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* (* 2.0 (PI)) (* (log alpha) (fma cosTheta (- cosTheta) 1.0)))))
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(\log \alpha \cdot \mathsf{fma}\left(cosTheta, -cosTheta, 1\right)\right)}
\end{array}
Initial program 98.4%
log-pow-revN/A
pow2N/A
lower-log.f32N/A
lower-pow.f32N/A
pow2N/A
lower-*.f32N/A
lower-PI.f3298.7
Applied rewrites98.7%
Taylor expanded in alpha around 0
log-pow-revN/A
+-commutativeN/A
associate-*r*N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-*.f32N/A
lower-log.f32N/A
*-commutativeN/A
pow2N/A
+-commutativeN/A
associate-*l*N/A
*-commutativeN/A
lower-fma.f32N/A
mul-1-negN/A
lower-neg.f3297.4
Applied rewrites97.4%
(FPCore (cosTheta alpha) :precision binary32 (/ (/ (- (* alpha alpha) 1.0) (PI)) (log (* alpha alpha))))
\begin{array}{l}
\\
\frac{\frac{\alpha \cdot \alpha - 1}{\mathsf{PI}\left(\right)}}{\log \left(\alpha \cdot \alpha\right)}
\end{array}
Initial program 98.4%
Taylor expanded in cosTheta around 0
associate-/r*N/A
lower-/.f32N/A
lower-/.f32N/A
lower--.f32N/A
pow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-log.f32N/A
pow2N/A
lower-*.f3294.8
Applied rewrites94.8%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* (* (PI) (log (* alpha alpha))) 1.0)))
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\left(\mathsf{PI}\left(\right) \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot 1}
\end{array}
Initial program 98.4%
Taylor expanded in cosTheta around 0
Applied rewrites94.7%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* (* 2.0 (PI)) (log alpha))))
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \log \alpha}
\end{array}
Initial program 98.4%
log-pow-revN/A
pow2N/A
lower-log.f32N/A
lower-pow.f32N/A
pow2N/A
lower-*.f32N/A
lower-PI.f3298.7
Applied rewrites98.7%
Taylor expanded in cosTheta around 0
log-pow-revN/A
+-commutativeN/A
associate-*r*N/A
pow-powN/A
log-pow-revN/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-log.f3294.7
Applied rewrites94.7%
(FPCore (cosTheta alpha) :precision binary32 (/ -1.0 (* (* (PI) (log (* alpha alpha))) 1.0)))
\begin{array}{l}
\\
\frac{-1}{\left(\mathsf{PI}\left(\right) \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot 1}
\end{array}
Initial program 98.4%
Taylor expanded in cosTheta around 0
Applied rewrites94.7%
Taylor expanded in alpha around 0
Applied rewrites67.0%
(FPCore (cosTheta alpha) :precision binary32 (/ -1.0 (* (* 2.0 (log alpha)) (PI))))
\begin{array}{l}
\\
\frac{-1}{\left(2 \cdot \log \alpha\right) \cdot \mathsf{PI}\left(\right)}
\end{array}
Initial program 98.4%
Taylor expanded in cosTheta around 0
Applied rewrites94.7%
Taylor expanded in alpha around 0
Applied rewrites67.0%
log-pow-revN/A
pow2N/A
pow-powN/A
log-pow-revN/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-log.f32N/A
lower-PI.f3267.0
Applied rewrites67.0%
Taylor expanded in cosTheta around 0
*-commutativeN/A
*-commutativeN/A
associate-*r*N/A
log-pow-revN/A
pow-powN/A
pow2N/A
log-pow-revN/A
associate-*r*N/A
log-pow-revN/A
pow-powN/A
log-pow-revN/A
*-commutativeN/A
lower-*.f32N/A
log-pow-revN/A
lower-*.f32N/A
lower-log.f32N/A
lower-PI.f3267.0
Applied rewrites67.0%
Final simplification67.0%
herbie shell --seed 2025044
(FPCore (cosTheta alpha)
:name "GTR1 distribution"
:precision binary32
:pre (and (and (<= 0.0 cosTheta) (<= cosTheta 1.0)) (and (<= 0.0001 alpha) (<= alpha 1.0)))
(/ (- (* alpha alpha) 1.0) (* (* (PI) (log (* alpha alpha))) (+ 1.0 (* (* (- (* alpha alpha) 1.0) cosTheta) cosTheta)))))