
(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 10 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 (* (fma (- maxCos 1.0) (fma ux (- 1.0 maxCos) -1.0) (- 1.0 maxCos)) ux))))
\begin{array}{l}
\\
\sin \left(\left(uy \cdot 2\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\mathsf{fma}\left(maxCos - 1, \mathsf{fma}\left(ux, 1 - maxCos, -1\right), 1 - maxCos\right) \cdot ux}
\end{array}
Initial program 58.7%
lift--.f32N/A
lift-*.f32N/A
fp-cancel-sub-sign-invN/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lower-fma.f32N/A
lower-neg.f3258.9
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lower-fma.f3258.9
Applied rewrites58.9%
Taylor expanded in ux around 0
*-commutativeN/A
lower-*.f32N/A
Applied rewrites98.3%
(FPCore (ux uy maxCos) :precision binary32 (* (sin (* (* uy 2.0) (PI))) (sqrt (* (- 2.0 (fma (fma -2.0 maxCos 1.0) ux (* 2.0 maxCos))) ux))))
\begin{array}{l}
\\
\sin \left(\left(uy \cdot 2\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\left(2 - \mathsf{fma}\left(\mathsf{fma}\left(-2, maxCos, 1\right), ux, 2 \cdot maxCos\right)\right) \cdot ux}
\end{array}
Initial program 58.7%
Taylor expanded in ux around 0
*-commutativeN/A
lower-*.f32N/A
fp-cancel-sub-sign-invN/A
metadata-evalN/A
+-commutativeN/A
lower-fma.f32N/A
associate-*r*N/A
mul-1-negN/A
fp-cancel-sub-signN/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-pow.f32N/A
lower--.f3298.2
Applied rewrites98.2%
Taylor expanded in maxCos around 0
Applied rewrites97.7%
Taylor expanded in ux around 0
Applied rewrites97.7%
Final simplification97.7%
(FPCore (ux uy maxCos) :precision binary32 (* (sin (* (* uy 2.0) (PI))) (sqrt (fma (* -2.0 ux) maxCos (* (- 2.0 ux) ux)))))
\begin{array}{l}
\\
\sin \left(\left(uy \cdot 2\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\mathsf{fma}\left(-2 \cdot ux, maxCos, \left(2 - ux\right) \cdot ux\right)}
\end{array}
Initial program 58.7%
Taylor expanded in ux around 0
*-commutativeN/A
lower-*.f32N/A
fp-cancel-sub-sign-invN/A
metadata-evalN/A
+-commutativeN/A
lower-fma.f32N/A
associate-*r*N/A
mul-1-negN/A
fp-cancel-sub-signN/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-pow.f32N/A
lower--.f3298.2
Applied rewrites98.2%
Taylor expanded in maxCos around 0
Applied rewrites98.2%
Taylor expanded in ux around 0
Applied rewrites96.7%
Final simplification96.7%
(FPCore (ux uy maxCos)
:precision binary32
(let* ((t_0 (* (- 2.0 ux) ux)))
(if (<= uy 7.899999764049426e-5)
(*
(* (* 2.0 uy) (PI))
(sqrt (fma (- (* (fma (- maxCos 2.0) ux 2.0) ux)) maxCos t_0)))
(* (sin (* (* uy 2.0) (PI))) (sqrt t_0)))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 - ux\right) \cdot ux\\
\mathbf{if}\;uy \leq 7.899999764049426 \cdot 10^{-5}:\\
\;\;\;\;\left(\left(2 \cdot uy\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\mathsf{fma}\left(-\mathsf{fma}\left(maxCos - 2, ux, 2\right) \cdot ux, maxCos, t\_0\right)}\\
\mathbf{else}:\\
\;\;\;\;\sin \left(\left(uy \cdot 2\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{t\_0}\\
\end{array}
\end{array}
if uy < 7.89999976e-5Initial program 59.9%
Taylor expanded in ux around 0
*-commutativeN/A
lower-*.f32N/A
fp-cancel-sub-sign-invN/A
metadata-evalN/A
+-commutativeN/A
lower-fma.f32N/A
associate-*r*N/A
mul-1-negN/A
fp-cancel-sub-signN/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-pow.f32N/A
lower--.f3298.2
Applied rewrites98.2%
Taylor expanded in maxCos around 0
Applied rewrites98.2%
Taylor expanded in ux around 0
Applied rewrites98.2%
Taylor expanded in uy around 0
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f3298.2
Applied rewrites98.2%
if 7.89999976e-5 < uy Initial program 56.8%
Taylor expanded in ux around 0
*-commutativeN/A
lower-*.f32N/A
fp-cancel-sub-sign-invN/A
metadata-evalN/A
+-commutativeN/A
lower-fma.f32N/A
associate-*r*N/A
mul-1-negN/A
fp-cancel-sub-signN/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-pow.f32N/A
lower--.f3298.2
Applied rewrites98.2%
Taylor expanded in maxCos around 0
Applied rewrites92.2%
Final simplification95.9%
(FPCore (ux uy maxCos) :precision binary32 (* (* (* 2.0 uy) (PI)) (sqrt (fma (- (* (fma (- maxCos 2.0) ux 2.0) ux)) maxCos (* (- 2.0 ux) ux)))))
\begin{array}{l}
\\
\left(\left(2 \cdot uy\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\mathsf{fma}\left(-\mathsf{fma}\left(maxCos - 2, ux, 2\right) \cdot ux, maxCos, \left(2 - ux\right) \cdot ux\right)}
\end{array}
Initial program 58.7%
Taylor expanded in ux around 0
*-commutativeN/A
lower-*.f32N/A
fp-cancel-sub-sign-invN/A
metadata-evalN/A
+-commutativeN/A
lower-fma.f32N/A
associate-*r*N/A
mul-1-negN/A
fp-cancel-sub-signN/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-pow.f32N/A
lower--.f3298.2
Applied rewrites98.2%
Taylor expanded in maxCos around 0
Applied rewrites98.2%
Taylor expanded in ux around 0
Applied rewrites98.2%
Taylor expanded in uy around 0
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f3281.6
Applied rewrites81.6%
Final simplification81.6%
(FPCore (ux uy maxCos) :precision binary32 (let* ((t_0 (fma maxCos ux (- 1.0 ux)))) (* (* (* (PI) 2.0) uy) (sqrt (fma t_0 (- t_0) 1.0)))))
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \mathsf{fma}\left(maxCos, ux, 1 - ux\right)\\
\left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot uy\right) \cdot \sqrt{\mathsf{fma}\left(t\_0, -t\_0, 1\right)}
\end{array}
\end{array}
Initial program 58.7%
Taylor expanded in uy around 0
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3251.9
Applied rewrites51.9%
lift--.f32N/A
lift-*.f32N/A
fp-cancel-sub-sign-invN/A
+-commutativeN/A
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lift-fma.f32N/A
*-commutativeN/A
lower-fma.f32N/A
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lift-fma.f32N/A
lower-neg.f3252.0
Applied rewrites52.0%
(FPCore (ux uy maxCos) :precision binary32 (* (* (* 2.0 uy) (PI)) (sqrt (fma (- ux (fma maxCos ux 1.0)) (- (fma maxCos ux 1.0) ux) 1.0))))
\begin{array}{l}
\\
\left(\left(2 \cdot uy\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\mathsf{fma}\left(ux - \mathsf{fma}\left(maxCos, ux, 1\right), \mathsf{fma}\left(maxCos, ux, 1\right) - ux, 1\right)}
\end{array}
Initial program 58.7%
lift--.f32N/A
lift-*.f32N/A
fp-cancel-sub-sign-invN/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lower-fma.f32N/A
lower-neg.f3258.9
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lower-fma.f3258.9
Applied rewrites58.9%
Taylor expanded in uy around 0
associate-*r*N/A
count-2-revN/A
distribute-lft-inN/A
count-2-revN/A
lower-*.f32N/A
count-2-revN/A
distribute-lft-inN/A
count-2-revN/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f32N/A
+-commutativeN/A
lower-fma.f32N/A
Applied rewrites51.9%
(FPCore (ux uy maxCos) :precision binary32 (* (* (* (PI) 2.0) uy) (sqrt (- 1.0 (* (+ (- 1.0 ux) (* ux maxCos)) (- 1.0 ux))))))
\begin{array}{l}
\\
\left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot uy\right) \cdot \sqrt{1 - \left(\left(1 - ux\right) + ux \cdot maxCos\right) \cdot \left(1 - ux\right)}
\end{array}
Initial program 58.7%
Taylor expanded in uy around 0
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3251.9
Applied rewrites51.9%
Taylor expanded in maxCos around 0
lower--.f3250.7
Applied rewrites50.7%
(FPCore (ux uy maxCos) :precision binary32 (* (* (+ (PI) (PI)) uy) (sqrt (- 1.0 (fma (- (* 2.0 maxCos) 2.0) ux 1.0)))))
\begin{array}{l}
\\
\left(\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot uy\right) \cdot \sqrt{1 - \mathsf{fma}\left(2 \cdot maxCos - 2, ux, 1\right)}
\end{array}
Initial program 58.7%
Taylor expanded in uy around 0
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3251.9
Applied rewrites51.9%
Taylor expanded in ux around 0
Applied rewrites7.1%
Applied rewrites7.1%
Taylor expanded in ux around 0
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
lower--.f32N/A
lower-*.f3241.1
Applied rewrites41.1%
(FPCore (ux uy maxCos) :precision binary32 (* (* (+ (PI) (PI)) uy) (sqrt (- 1.0 1.0))))
\begin{array}{l}
\\
\left(\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot uy\right) \cdot \sqrt{1 - 1}
\end{array}
Initial program 58.7%
Taylor expanded in uy around 0
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3251.9
Applied rewrites51.9%
Taylor expanded in ux around 0
Applied rewrites7.1%
Applied rewrites7.1%
herbie shell --seed 2024360
(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)))))))