
(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 98.3%
lift-*.f32N/A
*-commutativeN/A
lift-PI.f32N/A
add-log-expN/A
log-pow-revN/A
lower-log.f32N/A
lift-PI.f32N/A
pow-expN/A
*-commutativeN/A
lift-log.f32N/A
pow-to-expN/A
lower-pow.f3298.6
Applied rewrites98.6%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* (* (PI) (log (* alpha alpha))) (fma (* cosTheta (fma alpha alpha -1.0)) 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 \cdot \mathsf{fma}\left(\alpha, \alpha, -1\right), cosTheta, 1\right)}
\end{array}
Initial program 98.3%
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.3
lift-*.f32N/A
*-commutativeN/A
lower-*.f3298.3
lift--.f32N/A
lift-*.f32N/A
difference-of-sqr-1N/A
difference-of-sqr--1-revN/A
lower-fma.f3298.3
Applied rewrites98.3%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* (* (fma (* cosTheta (fma alpha alpha -1.0)) cosTheta 1.0) (PI)) (log (* alpha alpha)))))
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\left(\mathsf{fma}\left(cosTheta \cdot \mathsf{fma}\left(\alpha, \alpha, -1\right), cosTheta, 1\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \log \left(\alpha \cdot \alpha\right)}
\end{array}
Initial program 98.3%
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.3
lift-*.f32N/A
*-commutativeN/A
lower-*.f3298.3
lift--.f32N/A
lift-*.f32N/A
difference-of-sqr-1N/A
difference-of-sqr--1-revN/A
lower-fma.f3298.3
Applied rewrites98.3%
lift--.f32N/A
lift-*.f32N/A
difference-of-sqr-1N/A
difference-of-sqr--1N/A
lift-fma.f3298.2
lift-*.f32N/A
*-commutativeN/A
lift-fma.f32N/A
difference-of-sqr--1N/A
difference-of-sqr-1N/A
lift-*.f32N/A
lift--.f32N/A
lower-*.f32N/A
*-commutativeN/A
lift--.f32N/A
lift-*.f32N/A
lower-fma.f32N/A
+-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
Applied rewrites98.2%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* (* (PI) (log (* alpha alpha))) (fma (* cosTheta (fma alpha alpha -1.0)) cosTheta 1.0))))
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\left(\mathsf{PI}\left(\right) \cdot \log \left(\alpha \cdot \alpha\right)\right) \cdot \mathsf{fma}\left(cosTheta \cdot \mathsf{fma}\left(\alpha, \alpha, -1\right), cosTheta, 1\right)}
\end{array}
Initial program 98.3%
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
lower-fma.f3298.3
lift-*.f32N/A
*-commutativeN/A
lower-*.f3298.3
lift--.f32N/A
lift-*.f32N/A
difference-of-sqr-1N/A
difference-of-sqr--1-revN/A
lower-fma.f3298.3
Applied rewrites98.3%
lift--.f32N/A
lift-*.f32N/A
difference-of-sqr-1N/A
difference-of-sqr--1N/A
lift-fma.f3298.2
Applied rewrites98.2%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* (* (fma (* -1.0 cosTheta) cosTheta 1.0) (PI)) (log (* alpha alpha)))))
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\left(\mathsf{fma}\left(-1 \cdot cosTheta, cosTheta, 1\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \log \left(\alpha \cdot \alpha\right)}
\end{array}
Initial program 98.3%
lift--.f32N/A
lift-*.f32N/A
difference-of-sqr-1N/A
*-commutativeN/A
+-commutativeN/A
distribute-lft-inN/A
lower-fma.f32N/A
lower--.f32N/A
lower-*.f32N/A
lower--.f3298.2
Applied rewrites98.2%
Taylor expanded in alpha around 0
Applied rewrites96.9%
lift-fma.f32N/A
lift-*.f32N/A
*-rgt-identityN/A
*-commutativeN/A
distribute-rgt1-inN/A
*-rgt-identityN/A
lift--.f32N/A
difference-of-sqr--1N/A
lift-fma.f3296.9
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
Applied rewrites97.0%
(FPCore (cosTheta alpha) :precision binary32 (/ (- (* alpha alpha) 1.0) (* (* 2.0 (PI)) (* (- 1.0 (* cosTheta cosTheta)) (log alpha)))))
\begin{array}{l}
\\
\frac{\alpha \cdot \alpha - 1}{\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot \left(\left(1 - cosTheta \cdot cosTheta\right) \cdot \log \alpha\right)}
\end{array}
Initial program 98.3%
lift-*.f32N/A
*-commutativeN/A
lift-PI.f32N/A
add-log-expN/A
log-pow-revN/A
lower-log.f32N/A
lift-PI.f32N/A
pow-expN/A
*-commutativeN/A
lift-log.f32N/A
pow-to-expN/A
lower-pow.f3298.6
Applied rewrites98.6%
Taylor expanded in alpha around 0
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
*-commutativeN/A
lower-*.f32N/A
fp-cancel-sign-sub-invN/A
metadata-evalN/A
*-lft-identityN/A
lower--.f32N/A
unpow2N/A
lower-*.f32N/A
lower-log.f3297.0
Applied rewrites97.0%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma (* 0.5 alpha) alpha -0.5) (* (log alpha) (PI))))
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(0.5 \cdot \alpha, \alpha, -0.5\right)}{\log \alpha \cdot \mathsf{PI}\left(\right)}
\end{array}
Initial program 98.3%
Taylor expanded in alpha around 0
Applied rewrites67.5%
Taylor expanded in cosTheta around 0
associate-/r*N/A
lower-/.f32N/A
lower-/.f32N/A
lower--.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-log.f32N/A
unpow2N/A
lower-*.f3294.3
Applied rewrites94.3%
Taylor expanded in alpha around 0
Applied rewrites65.9%
Taylor expanded in alpha around 0
Applied rewrites94.3%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma (* -0.5 cosTheta) cosTheta -0.5) (* (log alpha) (PI))))
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(-0.5 \cdot cosTheta, cosTheta, -0.5\right)}{\log \alpha \cdot \mathsf{PI}\left(\right)}
\end{array}
Initial program 98.3%
Taylor expanded in alpha around 0
associate-*r*N/A
associate-/r*N/A
lower-/.f32N/A
lower-/.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-log.f32N/A
lower-PI.f32N/A
fp-cancel-sign-sub-invN/A
metadata-evalN/A
*-lft-identityN/A
lower--.f32N/A
unpow2N/A
lower-*.f3267.4
Applied rewrites67.4%
Taylor expanded in cosTheta around 0
Applied rewrites66.5%
(FPCore (cosTheta alpha) :precision binary32 (/ (/ -0.5 (PI)) (log alpha)))
\begin{array}{l}
\\
\frac{\frac{-0.5}{\mathsf{PI}\left(\right)}}{\log \alpha}
\end{array}
Initial program 98.3%
Taylor expanded in alpha around 0
Applied rewrites67.5%
Taylor expanded in cosTheta around 0
associate-/r*N/A
lower-/.f32N/A
lower-/.f32N/A
lower--.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-log.f32N/A
unpow2N/A
lower-*.f3294.3
Applied rewrites94.3%
Taylor expanded in alpha around 0
Applied rewrites65.9%
Applied rewrites65.9%
(FPCore (cosTheta alpha) :precision binary32 (/ -1.0 (* (log (* alpha alpha)) (PI))))
\begin{array}{l}
\\
\frac{-1}{\log \left(\alpha \cdot \alpha\right) \cdot \mathsf{PI}\left(\right)}
\end{array}
Initial program 98.3%
Taylor expanded in alpha around 0
Applied rewrites67.5%
Taylor expanded in cosTheta around 0
*-commutativeN/A
lower-*.f32N/A
lower-log.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f3265.9
Applied rewrites65.9%
(FPCore (cosTheta alpha) :precision binary32 (/ -0.5 (* (log alpha) (PI))))
\begin{array}{l}
\\
\frac{-0.5}{\log \alpha \cdot \mathsf{PI}\left(\right)}
\end{array}
Initial program 98.3%
Taylor expanded in alpha around 0
Applied rewrites67.5%
Taylor expanded in cosTheta around 0
associate-/r*N/A
lower-/.f32N/A
lower-/.f32N/A
lower--.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-log.f32N/A
unpow2N/A
lower-*.f3294.3
Applied rewrites94.3%
Taylor expanded in alpha around 0
Applied rewrites65.9%
(FPCore (cosTheta alpha) :precision binary32 (/ (fma alpha alpha -1.0) (* (NAN) (PI))))
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\alpha, \alpha, -1\right)}{\mathsf{NAN}\left(\right) \cdot \mathsf{PI}\left(\right)}
\end{array}
Initial program 98.3%
lift--.f32N/A
lift-*.f32N/A
difference-of-sqr-1N/A
difference-of-sqr--1-revN/A
lower-fma.f3298.2
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
Applied rewrites-0.0%
Taylor expanded in cosTheta around 0
lower-*.f32N/A
lower-NAN.f32N/A
lower-PI.f32-0.0
Applied rewrites-0.0%
herbie shell --seed 2024364
(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)))))