
(FPCore (ux uy maxCos) :precision binary32 (let* ((t_0 (+ (- 1.0 ux) (* ux maxCos)))) (* (cos (* (* 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\\
\cos \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)))) (* (cos (* (* 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\\
\cos \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
(let* ((t_0 (cos (* (PI) (* 2.0 uy)))))
(if (<= maxCos 5.00000006675716e-11)
(* (sqrt (* (- 2.0 ux) ux)) t_0)
(*
(sqrt
(*
(* maxCos maxCos)
(*
(-
(/ (/ (- (/ 2.0 ux) 1.0) maxCos) maxCos)
(- 1.0 (/ (- 2.0 (/ 2.0 ux)) maxCos)))
(* ux ux))))
t_0))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos \left(\mathsf{PI}\left(\right) \cdot \left(2 \cdot uy\right)\right)\\
\mathbf{if}\;maxCos \leq 5.00000006675716 \cdot 10^{-11}:\\
\;\;\;\;\sqrt{\left(2 - ux\right) \cdot ux} \cdot t\_0\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\left(maxCos \cdot maxCos\right) \cdot \left(\left(\frac{\frac{\frac{2}{ux} - 1}{maxCos}}{maxCos} - \left(1 - \frac{2 - \frac{2}{ux}}{maxCos}\right)\right) \cdot \left(ux \cdot ux\right)\right)} \cdot t\_0\\
\end{array}
\end{array}
if maxCos < 5.00000007e-11Initial program 60.3%
Taylor expanded in ux around inf
*-commutativeN/A
lower-*.f32N/A
associate--r+N/A
associate-*r/N/A
metadata-evalN/A
associate-*r/N/A
div-subN/A
cancel-sign-sub-invN/A
metadata-evalN/A
lower--.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-fma.f32N/A
lower-pow.f32N/A
lower--.f32N/A
unpow2N/A
lower-*.f3271.9
Applied rewrites71.9%
Taylor expanded in maxCos around 0
Applied rewrites98.6%
Taylor expanded in ux around 0
Applied rewrites98.8%
if 5.00000007e-11 < maxCos Initial program 59.5%
Taylor expanded in ux around inf
*-commutativeN/A
lower-*.f32N/A
associate--r+N/A
associate-*r/N/A
metadata-evalN/A
associate-*r/N/A
div-subN/A
cancel-sign-sub-invN/A
metadata-evalN/A
lower--.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-fma.f32N/A
lower-pow.f32N/A
lower--.f32N/A
unpow2N/A
lower-*.f3253.6
Applied rewrites53.6%
Applied rewrites98.7%
Taylor expanded in maxCos around inf
Applied rewrites98.8%
Final simplification98.8%
(FPCore (ux uy maxCos) :precision binary32 (* (sqrt (* (* ux ux) (- (/ (+ (* -2.0 maxCos) 2.0) ux) (pow (- maxCos 1.0) 2.0)))) (cos (* (PI) (* 2.0 uy)))))
\begin{array}{l}
\\
\sqrt{\left(ux \cdot ux\right) \cdot \left(\frac{-2 \cdot maxCos + 2}{ux} - {\left(maxCos - 1\right)}^{2}\right)} \cdot \cos \left(\mathsf{PI}\left(\right) \cdot \left(2 \cdot uy\right)\right)
\end{array}
Initial program 60.1%
Taylor expanded in ux around inf
*-commutativeN/A
lower-*.f32N/A
associate--r+N/A
associate-*r/N/A
metadata-evalN/A
associate-*r/N/A
div-subN/A
cancel-sign-sub-invN/A
metadata-evalN/A
lower--.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-fma.f32N/A
lower-pow.f32N/A
lower--.f32N/A
unpow2N/A
lower-*.f3267.9
Applied rewrites67.9%
Applied rewrites98.6%
Final simplification98.6%
(FPCore (ux uy maxCos)
:precision binary32
(let* ((t_0 (cos (* (PI) (* 2.0 uy)))))
(if (<= maxCos 5.00000006675716e-11)
(* (sqrt (* (- 2.0 ux) ux)) t_0)
(*
(sqrt
(*
(-
(*
(+
(/ (- (/ 2.0 ux) 1.0) (* maxCos maxCos))
(/ (- 2.0 (/ 2.0 ux)) maxCos))
(* ux ux))
(* ux ux))
(* maxCos maxCos)))
t_0))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos \left(\mathsf{PI}\left(\right) \cdot \left(2 \cdot uy\right)\right)\\
\mathbf{if}\;maxCos \leq 5.00000006675716 \cdot 10^{-11}:\\
\;\;\;\;\sqrt{\left(2 - ux\right) \cdot ux} \cdot t\_0\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\left(\left(\frac{\frac{2}{ux} - 1}{maxCos \cdot maxCos} + \frac{2 - \frac{2}{ux}}{maxCos}\right) \cdot \left(ux \cdot ux\right) - ux \cdot ux\right) \cdot \left(maxCos \cdot maxCos\right)} \cdot t\_0\\
\end{array}
\end{array}
if maxCos < 5.00000007e-11Initial program 60.3%
Taylor expanded in ux around inf
*-commutativeN/A
lower-*.f32N/A
associate--r+N/A
associate-*r/N/A
metadata-evalN/A
associate-*r/N/A
div-subN/A
cancel-sign-sub-invN/A
metadata-evalN/A
lower--.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-fma.f32N/A
lower-pow.f32N/A
lower--.f32N/A
unpow2N/A
lower-*.f3271.9
Applied rewrites71.9%
Taylor expanded in maxCos around 0
Applied rewrites98.6%
Taylor expanded in ux around 0
Applied rewrites98.8%
if 5.00000007e-11 < maxCos Initial program 59.5%
Taylor expanded in ux around inf
*-commutativeN/A
lower-*.f32N/A
associate--r+N/A
associate-*r/N/A
metadata-evalN/A
associate-*r/N/A
div-subN/A
cancel-sign-sub-invN/A
metadata-evalN/A
lower--.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-fma.f32N/A
lower-pow.f32N/A
lower--.f32N/A
unpow2N/A
lower-*.f3253.6
Applied rewrites53.6%
Taylor expanded in maxCos around inf
Applied rewrites98.7%
Final simplification98.8%
(FPCore (ux uy maxCos)
:precision binary32
(if (<= (* 2.0 uy) 0.0024999999441206455)
(*
(sqrt
(-
(* (- (/ 2.0 ux) (- (/ maxCos ux) (- maxCos 1.0))) (* ux ux))
(* (* (fma maxCos ux (- 1.0 ux)) maxCos) ux)))
(fma (* (* uy uy) -2.0) (* (PI) (PI)) 1.0))
(* (sqrt (* 2.0 ux)) (cos (* (PI) (* 2.0 uy))))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;2 \cdot uy \leq 0.0024999999441206455:\\
\;\;\;\;\sqrt{\left(\frac{2}{ux} - \left(\frac{maxCos}{ux} - \left(maxCos - 1\right)\right)\right) \cdot \left(ux \cdot ux\right) - \left(\mathsf{fma}\left(maxCos, ux, 1 - ux\right) \cdot maxCos\right) \cdot ux} \cdot \mathsf{fma}\left(\left(uy \cdot uy\right) \cdot -2, \mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right), 1\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{2 \cdot ux} \cdot \cos \left(\mathsf{PI}\left(\right) \cdot \left(2 \cdot uy\right)\right)\\
\end{array}
\end{array}
if (*.f32 uy #s(literal 2 binary32)) < 0.00249999994Initial program 59.8%
Taylor expanded in uy around 0
+-commutativeN/A
associate-*r*N/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3258.9
Applied rewrites58.4%
lift--.f32N/A
lift-*.f32N/A
lift-+.f32N/A
distribute-lft-inN/A
associate--r+N/A
*-commutativeN/A
lower--.f32N/A
lower--.f32N/A
lower-*.f32N/A
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lower-fma.f32N/A
*-commutativeN/A
Applied rewrites26.2%
Taylor expanded in ux around inf
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
associate-*r/N/A
metadata-evalN/A
lower-/.f32N/A
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
lower--.f32N/A
lower-/.f32N/A
lower--.f32N/A
unpow2N/A
lower-*.f3296.2
Applied rewrites96.2%
if 0.00249999994 < (*.f32 uy #s(literal 2 binary32)) Initial program 60.8%
Taylor expanded in ux around inf
*-commutativeN/A
lower-*.f32N/A
associate--r+N/A
associate-*r/N/A
metadata-evalN/A
associate-*r/N/A
div-subN/A
cancel-sign-sub-invN/A
metadata-evalN/A
lower--.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-fma.f32N/A
lower-pow.f32N/A
lower--.f32N/A
unpow2N/A
lower-*.f3218.2
Applied rewrites18.9%
Taylor expanded in maxCos around 0
Applied rewrites90.2%
Taylor expanded in ux around 0
Applied rewrites70.3%
Final simplification84.1%
(FPCore (ux uy maxCos) :precision binary32 (* (sqrt (* (- 2.0 ux) ux)) (cos (* (PI) (* 2.0 uy)))))
\begin{array}{l}
\\
\sqrt{\left(2 - ux\right) \cdot ux} \cdot \cos \left(\mathsf{PI}\left(\right) \cdot \left(2 \cdot uy\right)\right)
\end{array}
Initial program 60.1%
Taylor expanded in ux around inf
*-commutativeN/A
lower-*.f32N/A
associate--r+N/A
associate-*r/N/A
metadata-evalN/A
associate-*r/N/A
div-subN/A
cancel-sign-sub-invN/A
metadata-evalN/A
lower--.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-fma.f32N/A
lower-pow.f32N/A
lower--.f32N/A
unpow2N/A
lower-*.f3267.9
Applied rewrites67.9%
Taylor expanded in maxCos around 0
Applied rewrites92.3%
Taylor expanded in ux around 0
Applied rewrites92.5%
Final simplification92.5%
(FPCore (ux uy maxCos)
:precision binary32
(*
(sqrt
(-
(* (- (/ 2.0 ux) (- (/ maxCos ux) (- maxCos 1.0))) (* ux ux))
(* (* (fma maxCos ux (- 1.0 ux)) maxCos) ux)))
(fma (* (* uy uy) -2.0) (* (PI) (PI)) 1.0)))\begin{array}{l}
\\
\sqrt{\left(\frac{2}{ux} - \left(\frac{maxCos}{ux} - \left(maxCos - 1\right)\right)\right) \cdot \left(ux \cdot ux\right) - \left(\mathsf{fma}\left(maxCos, ux, 1 - ux\right) \cdot maxCos\right) \cdot ux} \cdot \mathsf{fma}\left(\left(uy \cdot uy\right) \cdot -2, \mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right), 1\right)
\end{array}
Initial program 60.1%
Taylor expanded in uy around 0
+-commutativeN/A
associate-*r*N/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3249.9
Applied rewrites49.7%
lift--.f32N/A
lift-*.f32N/A
lift-+.f32N/A
distribute-lft-inN/A
associate--r+N/A
*-commutativeN/A
lower--.f32N/A
lower--.f32N/A
lower-*.f32N/A
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lower-fma.f32N/A
*-commutativeN/A
Applied rewrites22.2%
Taylor expanded in ux around inf
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
associate-*r/N/A
metadata-evalN/A
lower-/.f32N/A
+-commutativeN/A
mul-1-negN/A
unsub-negN/A
lower--.f32N/A
lower-/.f32N/A
lower--.f32N/A
unpow2N/A
lower-*.f3275.6
Applied rewrites78.0%
Final simplification76.9%
(FPCore (ux uy maxCos)
:precision binary32
(let* ((t_0 (+ (* maxCos ux) (- 1.0 ux))) (t_1 (* (PI) (PI))))
(if (<= (- 1.0 (* t_0 t_0)) 0.00013000000035390258)
(* (sqrt (* (fma -2.0 maxCos 2.0) ux)) (fma uy (* (* t_1 -2.0) uy) 1.0))
(* (sqrt (- 1.0 (* (- 1.0 ux) t_0))) (fma (* (* uy uy) -2.0) t_1 1.0)))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := maxCos \cdot ux + \left(1 - ux\right)\\
t_1 := \mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\\
\mathbf{if}\;1 - t\_0 \cdot t\_0 \leq 0.00013000000035390258:\\
\;\;\;\;\sqrt{\mathsf{fma}\left(-2, maxCos, 2\right) \cdot ux} \cdot \mathsf{fma}\left(uy, \left(t\_1 \cdot -2\right) \cdot uy, 1\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{1 - \left(1 - ux\right) \cdot t\_0} \cdot \mathsf{fma}\left(\left(uy \cdot uy\right) \cdot -2, t\_1, 1\right)\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) (*.f32 (+.f32 (-.f32 #s(literal 1 binary32) ux) (*.f32 ux maxCos)) (+.f32 (-.f32 #s(literal 1 binary32) ux) (*.f32 ux maxCos)))) < 1.3e-4Initial program 34.5%
Taylor expanded in uy around 0
+-commutativeN/A
associate-*r*N/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3231.2
Applied rewrites30.9%
Taylor expanded in ux around 0
cancel-sign-sub-invN/A
metadata-evalN/A
*-commutativeN/A
lower-*.f32N/A
+-commutativeN/A
lower-fma.f3267.8
Applied rewrites71.6%
Applied rewrites69.9%
if 1.3e-4 < (-.f32 #s(literal 1 binary32) (*.f32 (+.f32 (-.f32 #s(literal 1 binary32) ux) (*.f32 ux maxCos)) (+.f32 (-.f32 #s(literal 1 binary32) ux) (*.f32 ux maxCos)))) Initial program 88.2%
Taylor expanded in uy around 0
+-commutativeN/A
associate-*r*N/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3270.6
Applied rewrites70.6%
Taylor expanded in maxCos around 0
lower--.f3263.8
Applied rewrites68.0%
Final simplification70.5%
(FPCore (ux uy maxCos) :precision binary32 (* (sqrt (* (* (- (/ 2.0 ux) 1.0) ux) ux)) (fma (* (* uy uy) -2.0) (* (PI) (PI)) 1.0)))
\begin{array}{l}
\\
\sqrt{\left(\left(\frac{2}{ux} - 1\right) \cdot ux\right) \cdot ux} \cdot \mathsf{fma}\left(\left(uy \cdot uy\right) \cdot -2, \mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right), 1\right)
\end{array}
Initial program 60.1%
Taylor expanded in ux around inf
*-commutativeN/A
lower-*.f32N/A
associate--r+N/A
associate-*r/N/A
metadata-evalN/A
associate-*r/N/A
div-subN/A
cancel-sign-sub-invN/A
metadata-evalN/A
lower--.f32N/A
lower-/.f32N/A
+-commutativeN/A
lower-fma.f32N/A
lower-pow.f32N/A
lower--.f32N/A
unpow2N/A
lower-*.f3267.9
Applied rewrites67.9%
Taylor expanded in maxCos around 0
Applied rewrites92.3%
Taylor expanded in uy around 0
+-commutativeN/A
associate-*r*N/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3274.4
Applied rewrites74.1%
Final simplification74.4%
(FPCore (ux uy maxCos) :precision binary32 (* (sqrt (* (fma -2.0 maxCos 2.0) ux)) (fma uy (* (* (* (PI) (PI)) -2.0) uy) 1.0)))
\begin{array}{l}
\\
\sqrt{\mathsf{fma}\left(-2, maxCos, 2\right) \cdot ux} \cdot \mathsf{fma}\left(uy, \left(\left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right) \cdot -2\right) \cdot uy, 1\right)
\end{array}
Initial program 60.1%
Taylor expanded in uy around 0
+-commutativeN/A
associate-*r*N/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3249.9
Applied rewrites49.7%
Taylor expanded in ux around 0
cancel-sign-sub-invN/A
metadata-evalN/A
*-commutativeN/A
lower-*.f32N/A
+-commutativeN/A
lower-fma.f3258.4
Applied rewrites59.7%
Applied rewrites59.9%
Final simplification58.0%
(FPCore (ux uy maxCos) :precision binary32 (* (sqrt (- 1.0 (* 1.0 1.0))) (fma (* (* uy uy) -2.0) (* (PI) (PI)) 1.0)))
\begin{array}{l}
\\
\sqrt{1 - 1 \cdot 1} \cdot \mathsf{fma}\left(\left(uy \cdot uy\right) \cdot -2, \mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right), 1\right)
\end{array}
Initial program 60.1%
Taylor expanded in uy around 0
+-commutativeN/A
associate-*r*N/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3249.9
Applied rewrites49.9%
Taylor expanded in ux around 0
Applied rewrites25.5%
Taylor expanded in ux around 0
Applied rewrites6.6%
Final simplification6.6%
herbie shell --seed 2024285
(FPCore (ux uy maxCos)
:name "UniformSampleCone, x"
: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)))
(* (cos (* (* uy 2.0) (PI))) (sqrt (- 1.0 (* (+ (- 1.0 ux) (* ux maxCos)) (+ (- 1.0 ux) (* ux maxCos)))))))