
(FPCore (ux uy maxCos) :precision binary32 (let* ((t_0 (+ (- 1.0 ux) (* ux maxCos)))) (* (sin (* (* uy 2.0) (PI))) (sqrt (- 1.0 (* t_0 t_0))))))
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(1 - ux\right) + ux \cdot maxCos\\
\sin \left(\left(uy \cdot 2\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{1 - t\_0 \cdot t\_0}
\end{array}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (ux uy maxCos) :precision binary32 (let* ((t_0 (+ (- 1.0 ux) (* ux maxCos)))) (* (sin (* (* uy 2.0) (PI))) (sqrt (- 1.0 (* t_0 t_0))))))
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(1 - ux\right) + ux \cdot maxCos\\
\sin \left(\left(uy \cdot 2\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{1 - t\_0 \cdot t\_0}
\end{array}
\end{array}
(FPCore (ux uy maxCos) :precision binary32 (* (sin (* (* uy 2.0) (PI))) (sqrt (* (- (- 2.0 (* (pow (- maxCos 1.0) 2.0) ux)) (* 2.0 maxCos)) ux))))
\begin{array}{l}
\\
\sin \left(\left(uy \cdot 2\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\left(\left(2 - {\left(maxCos - 1\right)}^{2} \cdot ux\right) - 2 \cdot maxCos\right) \cdot ux}
\end{array}
Initial program 56.8%
Taylor expanded in ux around inf
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
+-commutativeN/A
lower-+.f32N/A
lower-/.f3257.2
Applied rewrites57.2%
Taylor expanded in ux around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
mul-1-negN/A
unsub-negN/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-pow.f32N/A
lower--.f32N/A
lower-*.f3298.4
Applied rewrites98.4%
(FPCore (ux uy maxCos) :precision binary32 (* (sin (* (* uy 2.0) (PI))) (sqrt (* (- (- 2.0 (* (fma -2.0 ux 2.0) maxCos)) ux) ux))))
\begin{array}{l}
\\
\sin \left(\left(uy \cdot 2\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\left(\left(2 - \mathsf{fma}\left(-2, ux, 2\right) \cdot maxCos\right) - ux\right) \cdot ux}
\end{array}
Initial program 56.8%
Taylor expanded in ux around inf
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
+-commutativeN/A
lower-+.f32N/A
lower-/.f3257.2
Applied rewrites57.2%
Taylor expanded in ux around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
mul-1-negN/A
unsub-negN/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-pow.f32N/A
lower--.f32N/A
lower-*.f3298.4
Applied rewrites98.4%
Taylor expanded in maxCos around 0
Applied rewrites88.8%
(FPCore (ux uy maxCos) :precision binary32 (* (sin (* (* uy 2.0) (PI))) (sqrt (* (- 2.0 ux) ux))))
\begin{array}{l}
\\
\sin \left(\left(uy \cdot 2\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\left(2 - ux\right) \cdot ux}
\end{array}
Initial program 56.8%
Taylor expanded in ux around inf
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
+-commutativeN/A
lower-+.f32N/A
lower-/.f3257.2
Applied rewrites57.2%
Taylor expanded in ux around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
mul-1-negN/A
unsub-negN/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-pow.f32N/A
lower--.f32N/A
lower-*.f3298.4
Applied rewrites98.4%
Taylor expanded in maxCos around 0
Applied rewrites92.1%
(FPCore (ux uy maxCos) :precision binary32 (* (* (* (PI) 2.0) uy) (sqrt (+ ux (* (- 1.0 ux) ux)))))
\begin{array}{l}
\\
\left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot uy\right) \cdot \sqrt{ux + \left(1 - ux\right) \cdot ux}
\end{array}
Initial program 56.8%
Taylor expanded in uy around 0
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3250.7
Applied rewrites50.7%
lift-*.f32N/A
lift-+.f32N/A
distribute-rgt-inN/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift--.f32N/A
sub-negN/A
lift-neg.f32N/A
+-commutativeN/A
distribute-rgt-inN/A
associate-+r+N/A
lift-+.f32N/A
distribute-lft-inN/A
lower-fma.f32N/A
Applied rewrites25.4%
Taylor expanded in maxCos around 0
associate-*r*N/A
mul-1-negN/A
cancel-sign-subN/A
lower-+.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower--.f3279.5
Applied rewrites79.5%
Final simplification79.5%
(FPCore (ux uy maxCos) :precision binary32 (* (* (* (PI) 2.0) uy) (sqrt (* 2.0 ux))))
\begin{array}{l}
\\
\left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot uy\right) \cdot \sqrt{2 \cdot ux}
\end{array}
Initial program 56.8%
Taylor expanded in uy around 0
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3250.7
Applied rewrites50.7%
Taylor expanded in maxCos around 0
lower--.f3249.1
Applied rewrites49.1%
Taylor expanded in ux around 0
*-commutativeN/A
lower-*.f32N/A
cancel-sign-sub-invN/A
metadata-evalN/A
+-commutativeN/A
lower-fma.f3265.0
Applied rewrites64.6%
Taylor expanded in maxCos around 0
Applied rewrites65.0%
herbie shell --seed 2024313
(FPCore (ux uy maxCos)
:name "UniformSampleCone, y"
:precision binary32
:pre (and (and (and (<= 2.328306437e-10 ux) (<= ux 1.0)) (and (<= 2.328306437e-10 uy) (<= uy 1.0))) (and (<= 0.0 maxCos) (<= maxCos 1.0)))
(* (sin (* (* uy 2.0) (PI))) (sqrt (- 1.0 (* (+ (- 1.0 ux) (* ux maxCos)) (+ (- 1.0 ux) (* ux maxCos)))))))