
(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 9 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 (* (sqrt (* (- (- 2.0 (* (pow (- maxCos 1.0) 2.0) ux)) (* maxCos 2.0)) ux)) (sin (* (PI) (* 2.0 uy)))))
\begin{array}{l}
\\
\sqrt{\left(\left(2 - {\left(maxCos - 1\right)}^{2} \cdot ux\right) - maxCos \cdot 2\right) \cdot ux} \cdot \sin \left(\mathsf{PI}\left(\right) \cdot \left(2 \cdot uy\right)\right)
\end{array}
Initial program 59.8%
lift-+.f32N/A
+-commutativeN/A
lift--.f32N/A
flip--N/A
metadata-evalN/A
div-subN/A
associate-+r-N/A
lower--.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-fma.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-+.f32N/A
lower-/.f32N/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f3223.1
Applied rewrites22.6%
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%
Final simplification98.4%
(FPCore (ux uy maxCos) :precision binary32 (* (sqrt (- (* (- 2.0 ux) ux) (* (* (fma -2.0 ux 2.0) ux) maxCos))) (sin (* (PI) (* 2.0 uy)))))
\begin{array}{l}
\\
\sqrt{\left(2 - ux\right) \cdot ux - \left(\mathsf{fma}\left(-2, ux, 2\right) \cdot ux\right) \cdot maxCos} \cdot \sin \left(\mathsf{PI}\left(\right) \cdot \left(2 \cdot uy\right)\right)
\end{array}
Initial program 59.8%
lift-+.f32N/A
+-commutativeN/A
lift--.f32N/A
flip--N/A
metadata-evalN/A
div-subN/A
associate-+r-N/A
lower--.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-fma.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-+.f32N/A
lower-/.f32N/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f3221.5
Applied rewrites22.2%
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 rewrites81.2%
Final simplification84.2%
(FPCore (ux uy maxCos) :precision binary32 (* (sqrt (* (- (- 2.0 (* (fma -2.0 ux 2.0) maxCos)) ux) ux)) (sin (* (PI) (* 2.0 uy)))))
\begin{array}{l}
\\
\sqrt{\left(\left(2 - \mathsf{fma}\left(-2, ux, 2\right) \cdot maxCos\right) - ux\right) \cdot ux} \cdot \sin \left(\mathsf{PI}\left(\right) \cdot \left(2 \cdot uy\right)\right)
\end{array}
Initial program 59.8%
lift-+.f32N/A
+-commutativeN/A
lift--.f32N/A
flip--N/A
metadata-evalN/A
div-subN/A
associate-+r-N/A
lower--.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-fma.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-+.f32N/A
lower-/.f32N/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f3221.7
Applied rewrites20.5%
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 rewrites81.7%
Final simplification84.7%
(FPCore (ux uy maxCos)
:precision binary32
(if (<= (* 2.0 uy) 0.0002800000074785203)
(*
(* (* (PI) 2.0) uy)
(sqrt (* (- (- 2.0 (* (fma -2.0 ux 2.0) maxCos)) ux) ux)))
(* (sqrt (* (- 2.0 ux) ux)) (sin (* (PI) (* 2.0 uy))))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;2 \cdot uy \leq 0.0002800000074785203:\\
\;\;\;\;\left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot uy\right) \cdot \sqrt{\left(\left(2 - \mathsf{fma}\left(-2, ux, 2\right) \cdot maxCos\right) - ux\right) \cdot ux}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\left(2 - ux\right) \cdot ux} \cdot \sin \left(\mathsf{PI}\left(\right) \cdot \left(2 \cdot uy\right)\right)\\
\end{array}
\end{array}
if (*.f32 uy #s(literal 2 binary32)) < 2.80000007e-4Initial program 58.9%
lift-+.f32N/A
+-commutativeN/A
lift--.f32N/A
flip--N/A
metadata-evalN/A
div-subN/A
associate-+r-N/A
lower--.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-fma.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-+.f32N/A
lower-/.f32N/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f3227.6
Applied rewrites29.1%
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-*.f3298.7
Applied rewrites98.7%
Taylor expanded in uy around 0
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3298.7
Applied rewrites98.7%
Taylor expanded in maxCos around 0
Applied rewrites97.8%
if 2.80000007e-4 < (*.f32 uy #s(literal 2 binary32)) Initial program 60.9%
lift-+.f32N/A
+-commutativeN/A
lift--.f32N/A
flip--N/A
metadata-evalN/A
div-subN/A
associate-+r-N/A
lower--.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-fma.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-+.f32N/A
lower-/.f32N/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f3214.0
Applied rewrites14.0%
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-*.f3298.0
Applied rewrites98.0%
Taylor expanded in maxCos around 0
Applied rewrites91.3%
Final simplification88.5%
(FPCore (ux uy maxCos) :precision binary32 (* (* (* (PI) 2.0) uy) (sqrt (* (- (- 2.0 (* (fma -2.0 ux 2.0) maxCos)) ux) ux))))
\begin{array}{l}
\\
\left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot uy\right) \cdot \sqrt{\left(\left(2 - \mathsf{fma}\left(-2, ux, 2\right) \cdot maxCos\right) - ux\right) \cdot ux}
\end{array}
Initial program 59.8%
lift-+.f32N/A
+-commutativeN/A
lift--.f32N/A
flip--N/A
metadata-evalN/A
div-subN/A
associate-+r-N/A
lower--.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-fma.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-+.f32N/A
lower-/.f32N/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f3221.3
Applied rewrites21.2%
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 uy around 0
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3277.9
Applied rewrites77.9%
Taylor expanded in maxCos around 0
Applied rewrites77.0%
(FPCore (ux uy maxCos) :precision binary32 (* (sqrt (* (- 2.0 ux) ux)) (* (* (PI) 2.0) uy)))
\begin{array}{l}
\\
\sqrt{\left(2 - ux\right) \cdot ux} \cdot \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot uy\right)
\end{array}
Initial program 59.8%
lift-+.f32N/A
+-commutativeN/A
lift--.f32N/A
flip--N/A
metadata-evalN/A
div-subN/A
associate-+r-N/A
lower--.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-fma.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-+.f32N/A
lower-/.f32N/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f3222.0
Applied rewrites21.5%
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 uy around 0
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3277.9
Applied rewrites77.9%
Taylor expanded in maxCos around 0
Applied rewrites73.9%
Final simplification73.9%
(FPCore (ux uy maxCos) :precision binary32 (* (sqrt (fma -1.0 1.0 1.0)) (fma uy (PI) (* (PI) uy))))
\begin{array}{l}
\\
\sqrt{\mathsf{fma}\left(-1, 1, 1\right)} \cdot \mathsf{fma}\left(uy, \mathsf{PI}\left(\right), \mathsf{PI}\left(\right) \cdot uy\right)
\end{array}
Initial program 59.8%
Taylor expanded in uy around 0
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3250.5
Applied rewrites50.5%
Taylor expanded in ux around 0
Applied rewrites7.1%
lift--.f32N/A
sub-negN/A
+-commutativeN/A
neg-mul-1N/A
lower-fma.f3219.9
Applied rewrites20.3%
Applied rewrites21.1%
Final simplification20.1%
(FPCore (ux uy maxCos) :precision binary32 (* (* (+ uy uy) (PI)) (sqrt (fma -1.0 1.0 1.0))))
\begin{array}{l}
\\
\left(\left(uy + uy\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\mathsf{fma}\left(-1, 1, 1\right)}
\end{array}
Initial program 59.8%
Taylor expanded in uy around 0
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3250.5
Applied rewrites50.5%
Taylor expanded in ux around 0
Applied rewrites7.1%
lift--.f32N/A
sub-negN/A
+-commutativeN/A
neg-mul-1N/A
lower-fma.f3220.3
Applied rewrites20.3%
Applied rewrites20.3%
Final simplification20.3%
(FPCore (ux uy maxCos) :precision binary32 (* (sqrt (- 1.0 1.0)) (* (* (PI) 2.0) uy)))
\begin{array}{l}
\\
\sqrt{1 - 1} \cdot \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot uy\right)
\end{array}
Initial program 59.8%
Taylor expanded in uy around 0
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3250.5
Applied rewrites50.5%
Taylor expanded in ux around 0
Applied rewrites7.1%
Final simplification7.1%
herbie shell --seed 2024266
(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)))))))