
(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 12 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 uy) (PI))) (sqrt (* (- (- 2.0 (* maxCos 2.0)) (* (fma (- maxCos 2.0) maxCos 1.0) ux)) ux))))
\begin{array}{l}
\\
\sin \left(\left(uy + uy\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\left(\left(2 - maxCos \cdot 2\right) - \mathsf{fma}\left(maxCos - 2, maxCos, 1\right) \cdot ux\right) \cdot ux}
\end{array}
Initial program 56.4%
Taylor expanded in ux around 0
Applied rewrites98.1%
Applied rewrites98.1%
Taylor expanded in maxCos around 0
Applied rewrites98.1%
lift-*.f32N/A
*-commutativeN/A
count-2-revN/A
lower-+.f3298.1
Applied rewrites98.1%
(FPCore (ux uy maxCos) :precision binary32 (* (sin (* (* uy 2.0) (PI))) (sqrt (* (- 2.0 (fma (fma ux (+ -2.0 maxCos) 2.0) maxCos ux)) 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(ux, -2 + maxCos, 2\right), maxCos, ux\right)\right) \cdot ux}
\end{array}
Initial program 56.4%
Taylor expanded in ux around 0
Applied rewrites98.1%
Taylor expanded in maxCos around 0
Applied rewrites98.1%
(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 56.4%
Taylor expanded in ux around 0
Applied rewrites98.1%
Taylor expanded in maxCos around 0
Applied rewrites97.6%
(FPCore (ux uy maxCos) :precision binary32 (* (sin (* (* uy 2.0) (PI))) (sqrt (* (- 2.0 (fma (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(2 - \mathsf{fma}\left(\mathsf{fma}\left(-2, ux, 2\right), maxCos, ux\right)\right) \cdot ux}
\end{array}
Initial program 56.4%
Taylor expanded in ux around 0
Applied rewrites98.1%
Taylor expanded in maxCos around 0
Applied rewrites97.6%
(FPCore (ux uy maxCos) :precision binary32 (* (sin (* (* uy 2.0) (PI))) (sqrt (* (- (- 2.0 (* maxCos 2.0)) ux) ux))))
\begin{array}{l}
\\
\sin \left(\left(uy \cdot 2\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\left(\left(2 - maxCos \cdot 2\right) - ux\right) \cdot ux}
\end{array}
Initial program 56.4%
Taylor expanded in ux around 0
Applied rewrites98.1%
Applied rewrites98.1%
Taylor expanded in maxCos around 0
Applied rewrites96.8%
(FPCore (ux uy maxCos)
:precision binary32
(if (<= uy 0.0002500000118743628)
(*
(* (* (PI) uy) 2.0)
(sqrt
(* (- (- 2.0 (* maxCos 2.0)) (* (fma (- maxCos 2.0) maxCos 1.0) ux)) ux)))
(* (sin (* (* uy 2.0) (PI))) (sqrt (* (- 2.0 ux) ux)))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;uy \leq 0.0002500000118743628:\\
\;\;\;\;\left(\left(\mathsf{PI}\left(\right) \cdot uy\right) \cdot 2\right) \cdot \sqrt{\left(\left(2 - maxCos \cdot 2\right) - \mathsf{fma}\left(maxCos - 2, maxCos, 1\right) \cdot ux\right) \cdot ux}\\
\mathbf{else}:\\
\;\;\;\;\sin \left(\left(uy \cdot 2\right) \cdot \mathsf{PI}\left(\right)\right) \cdot \sqrt{\left(2 - ux\right) \cdot ux}\\
\end{array}
\end{array}
if uy < 2.50000012e-4Initial program 55.7%
Taylor expanded in ux around 0
Applied rewrites98.4%
Applied rewrites98.4%
Taylor expanded in maxCos around 0
Applied rewrites98.4%
Taylor expanded in uy around 0
Applied rewrites98.2%
if 2.50000012e-4 < uy Initial program 57.7%
Taylor expanded in ux around 0
Applied rewrites97.5%
Taylor expanded in maxCos around 0
Applied rewrites93.2%
Final simplification96.5%
(FPCore (ux uy maxCos)
:precision binary32
(let* ((t_0 (* (* (PI) 2.0) uy))
(t_1 (+ (- 1.0 ux) (* ux maxCos)))
(t_2 (- (fma maxCos ux 1.0) ux)))
(if (<= (sqrt (- 1.0 (* t_1 t_1))) 0.020999999716877937)
(* t_0 (sqrt (* (fma -2.0 maxCos 2.0) ux)))
(* t_0 (sqrt (fma t_2 (- t_2) 1.0))))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot uy\\
t_1 := \left(1 - ux\right) + ux \cdot maxCos\\
t_2 := \mathsf{fma}\left(maxCos, ux, 1\right) - ux\\
\mathbf{if}\;\sqrt{1 - t\_1 \cdot t\_1} \leq 0.020999999716877937:\\
\;\;\;\;t\_0 \cdot \sqrt{\mathsf{fma}\left(-2, maxCos, 2\right) \cdot ux}\\
\mathbf{else}:\\
\;\;\;\;t\_0 \cdot \sqrt{\mathsf{fma}\left(t\_2, -t\_2, 1\right)}\\
\end{array}
\end{array}
if (sqrt.f32 (-.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))))) < 0.0209999997Initial program 39.2%
Taylor expanded in uy around 0
Applied rewrites34.3%
lift--.f32N/A
flip--N/A
lower-/.f32N/A
metadata-evalN/A
lower--.f32N/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f3234.2
Applied rewrites34.2%
Taylor expanded in ux around 0
Applied rewrites75.5%
if 0.0209999997 < (sqrt.f32 (-.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
Applied rewrites76.4%
lift--.f32N/A
flip--N/A
lower-/.f32N/A
metadata-evalN/A
lower--.f32N/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f3276.0
Applied rewrites76.0%
lift--.f32N/A
lift-*.f32N/A
lift-+.f32N/A
lift-*.f32N/A
*-commutativeN/A
+-commutativeN/A
lift--.f32N/A
associate-+r-N/A
lift-fma.f32N/A
lift--.f32N/A
*-commutativeN/A
fp-cancel-sub-sign-invN/A
Applied rewrites76.6%
(FPCore (ux uy maxCos)
:precision binary32
(let* ((t_0 (* (* (PI) 2.0) uy))
(t_1 (+ (- 1.0 ux) (* ux maxCos)))
(t_2 (- (fma maxCos ux 1.0) ux)))
(if (<= (sqrt (- 1.0 (* t_1 t_1))) 0.019999999552965164)
(* t_0 (sqrt (* (fma -2.0 maxCos 2.0) ux)))
(* t_0 (sqrt (- 1.0 (* t_2 t_2)))))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot uy\\
t_1 := \left(1 - ux\right) + ux \cdot maxCos\\
t_2 := \mathsf{fma}\left(maxCos, ux, 1\right) - ux\\
\mathbf{if}\;\sqrt{1 - t\_1 \cdot t\_1} \leq 0.019999999552965164:\\
\;\;\;\;t\_0 \cdot \sqrt{\mathsf{fma}\left(-2, maxCos, 2\right) \cdot ux}\\
\mathbf{else}:\\
\;\;\;\;t\_0 \cdot \sqrt{1 - t\_2 \cdot t\_2}\\
\end{array}
\end{array}
if (sqrt.f32 (-.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))))) < 0.0199999996Initial program 39.0%
Taylor expanded in uy around 0
Applied rewrites34.3%
lift--.f32N/A
flip--N/A
lower-/.f32N/A
metadata-evalN/A
lower--.f32N/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f3234.1
Applied rewrites34.1%
Taylor expanded in ux around 0
Applied rewrites75.7%
if 0.0199999996 < (sqrt.f32 (-.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 88.0%
Taylor expanded in uy around 0
Applied rewrites76.0%
lift--.f32N/A
flip--N/A
lower-/.f32N/A
metadata-evalN/A
lower--.f32N/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f3275.6
Applied rewrites75.6%
lift-+.f32N/A
+-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
lift--.f32N/A
metadata-evalN/A
lift-*.f32N/A
lift-+.f32N/A
+-commutativeN/A
flip--N/A
associate-+r-N/A
lift-fma.f32N/A
lift--.f3276.1
lift-+.f32N/A
lift-*.f32N/A
*-commutativeN/A
+-commutativeN/A
lift--.f32N/A
associate-+r-N/A
lift-fma.f32N/A
lift--.f3276.1
Applied rewrites76.1%
(FPCore (ux uy maxCos)
:precision binary32
(let* ((t_0 (* (* (PI) 2.0) uy)) (t_1 (+ (- 1.0 ux) (* ux maxCos))))
(if (<= (sqrt (- 1.0 (* t_1 t_1))) 0.019999999552965164)
(* t_0 (sqrt (* (fma -2.0 maxCos 2.0) ux)))
(* t_0 (sqrt (- 1.0 (* t_1 (- 1.0 ux))))))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot uy\\
t_1 := \left(1 - ux\right) + ux \cdot maxCos\\
\mathbf{if}\;\sqrt{1 - t\_1 \cdot t\_1} \leq 0.019999999552965164:\\
\;\;\;\;t\_0 \cdot \sqrt{\mathsf{fma}\left(-2, maxCos, 2\right) \cdot ux}\\
\mathbf{else}:\\
\;\;\;\;t\_0 \cdot \sqrt{1 - t\_1 \cdot \left(1 - ux\right)}\\
\end{array}
\end{array}
if (sqrt.f32 (-.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))))) < 0.0199999996Initial program 39.0%
Taylor expanded in uy around 0
Applied rewrites34.3%
lift--.f32N/A
flip--N/A
lower-/.f32N/A
metadata-evalN/A
lower--.f32N/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f3234.1
Applied rewrites34.1%
Taylor expanded in ux around 0
Applied rewrites75.7%
if 0.0199999996 < (sqrt.f32 (-.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 88.0%
Taylor expanded in uy around 0
Applied rewrites76.0%
Taylor expanded in maxCos around 0
Applied rewrites74.1%
(FPCore (ux uy maxCos) :precision binary32 (* (* (* (PI) uy) 2.0) (sqrt (* (- (- 2.0 (* maxCos 2.0)) (* (fma (- maxCos 2.0) maxCos 1.0) ux)) ux))))
\begin{array}{l}
\\
\left(\left(\mathsf{PI}\left(\right) \cdot uy\right) \cdot 2\right) \cdot \sqrt{\left(\left(2 - maxCos \cdot 2\right) - \mathsf{fma}\left(maxCos - 2, maxCos, 1\right) \cdot ux\right) \cdot ux}
\end{array}
Initial program 56.4%
Taylor expanded in ux around 0
Applied rewrites98.1%
Applied rewrites98.1%
Taylor expanded in maxCos around 0
Applied rewrites98.1%
Taylor expanded in uy around 0
Applied rewrites80.9%
Final simplification80.9%
(FPCore (ux uy maxCos) :precision binary32 (* (* (* (PI) 2.0) uy) (sqrt (* (fma -2.0 maxCos 2.0) ux))))
\begin{array}{l}
\\
\left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot uy\right) \cdot \sqrt{\mathsf{fma}\left(-2, maxCos, 2\right) \cdot ux}
\end{array}
Initial program 56.4%
Taylor expanded in uy around 0
Applied rewrites49.1%
lift--.f32N/A
flip--N/A
lower-/.f32N/A
metadata-evalN/A
lower--.f32N/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f3248.9
Applied rewrites48.9%
Taylor expanded in ux around 0
Applied rewrites66.1%
(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 56.4%
Taylor expanded in uy around 0
Applied rewrites49.1%
Taylor expanded in ux around 0
Applied rewrites7.2%
Applied rewrites7.2%
herbie shell --seed 2025018
(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)))))))