
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (sin (* (* 2.0 (PI)) u2))))
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (sin (* (* 2.0 (PI)) u2))))
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (- (log (- 1.0 u1)))) (t_1 (pow (PI) 0.16666666666666666)))
(if (<= t_0 0.00010599999950500205)
(* (pow (* u1 u1) 0.25) (sin (* (+ u2 u2) (PI))))
(*
(sin (* (* (* (* t_1 u2) t_1) 2.0) (pow (cbrt (PI)) 2.0)))
(sqrt t_0)))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := -\log \left(1 - u1\right)\\
t_1 := {\mathsf{PI}\left(\right)}^{0.16666666666666666}\\
\mathbf{if}\;t\_0 \leq 0.00010599999950500205:\\
\;\;\;\;{\left(u1 \cdot u1\right)}^{0.25} \cdot \sin \left(\left(u2 + u2\right) \cdot \mathsf{PI}\left(\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin \left(\left(\left(\left(t\_1 \cdot u2\right) \cdot t\_1\right) \cdot 2\right) \cdot {\left(\sqrt[3]{\mathsf{PI}\left(\right)}\right)}^{2}\right) \cdot \sqrt{t\_0}\\
\end{array}
\end{array}
if (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1))) < 1.06e-4Initial program 34.4%
Applied rewrites45.3%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f3293.5
Applied rewrites93.5%
Applied rewrites93.6%
Applied rewrites93.6%
if 1.06e-4 < (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1))) Initial program 89.3%
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
lift-PI.f32N/A
add-cube-cbrtN/A
associate-*l*N/A
associate-*l*N/A
lower-*.f32N/A
pow2N/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-cbrt.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lift-PI.f32N/A
lower-cbrt.f3289.2
Applied rewrites89.2%
lift-*.f32N/A
lift-cbrt.f32N/A
pow1/3N/A
sqr-powN/A
associate-*l*N/A
lower-*.f32N/A
lower-pow.f32N/A
metadata-evalN/A
lower-*.f32N/A
lower-pow.f32N/A
metadata-eval89.4
Applied rewrites89.4%
Final simplification92.0%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (- (log (- 1.0 u1)))))
(if (<= t_0 0.00010599999950500205)
(* (pow (* u1 u1) 0.25) (sin (* (+ u2 u2) (PI))))
(* (sin (* (* (PI) 2.0) u2)) (sqrt t_0)))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := -\log \left(1 - u1\right)\\
\mathbf{if}\;t\_0 \leq 0.00010599999950500205:\\
\;\;\;\;{\left(u1 \cdot u1\right)}^{0.25} \cdot \sin \left(\left(u2 + u2\right) \cdot \mathsf{PI}\left(\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sin \left(\left(\mathsf{PI}\left(\right) \cdot 2\right) \cdot u2\right) \cdot \sqrt{t\_0}\\
\end{array}
\end{array}
if (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1))) < 1.06e-4Initial program 34.4%
Applied rewrites45.2%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f3293.5
Applied rewrites93.5%
Applied rewrites93.6%
Applied rewrites93.6%
if 1.06e-4 < (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1))) Initial program 89.3%
Final simplification91.9%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= (- (log (- 1.0 u1))) 0.0009399999980814755)
(* (pow (* u1 u1) 0.25) (sin (* (+ u2 u2) (PI))))
(*
(sqrt (log (sqrt (/ 1.0 (- 1.0 u1)))))
(* (* (* (sqrt 2.0) (PI)) u2) 2.0))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;-\log \left(1 - u1\right) \leq 0.0009399999980814755:\\
\;\;\;\;{\left(u1 \cdot u1\right)}^{0.25} \cdot \sin \left(\left(u2 + u2\right) \cdot \mathsf{PI}\left(\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\log \left(\sqrt{\frac{1}{1 - u1}}\right)} \cdot \left(\left(\left(\sqrt{2} \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \cdot 2\right)\\
\end{array}
\end{array}
if (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1))) < 9.39999998e-4Initial program 39.9%
Applied rewrites44.9%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f3290.3
Applied rewrites90.3%
Applied rewrites90.4%
Applied rewrites90.4%
if 9.39999998e-4 < (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1))) Initial program 92.8%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
inv-powN/A
sqr-powN/A
log-prodN/A
lower-+.f32N/A
lower-log.f32N/A
lower-pow.f32N/A
metadata-evalN/A
lower-log.f32N/A
lower-pow.f32N/A
metadata-eval88.1
Applied rewrites88.1%
Taylor expanded in u2 around 0
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-sqrt.f32N/A
lower-PI.f32N/A
lower-sqrt.f32N/A
lower-log.f32N/A
lower-sqrt.f32N/A
sub-negN/A
mul-1-negN/A
lower-/.f32N/A
mul-1-negN/A
sub-negN/A
lower--.f3278.3
Applied rewrites78.3%
Final simplification86.8%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= (- 1.0 u1) 0.9990599751472473)
(*
(sqrt (log (sqrt (/ 1.0 (- 1.0 u1)))))
(* (* (* (sqrt 2.0) (PI)) u2) 2.0))
(* (sqrt u1) (sin (* (+ u2 u2) (PI))))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u1 \leq 0.9990599751472473:\\
\;\;\;\;\sqrt{\log \left(\sqrt{\frac{1}{1 - u1}}\right)} \cdot \left(\left(\left(\sqrt{2} \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \cdot 2\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \sin \left(\left(u2 + u2\right) \cdot \mathsf{PI}\left(\right)\right)\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u1) < 0.999059975Initial program 92.8%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
inv-powN/A
sqr-powN/A
log-prodN/A
lower-+.f32N/A
lower-log.f32N/A
lower-pow.f32N/A
metadata-evalN/A
lower-log.f32N/A
lower-pow.f32N/A
metadata-eval88.1
Applied rewrites88.1%
Taylor expanded in u2 around 0
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-sqrt.f32N/A
lower-PI.f32N/A
lower-sqrt.f32N/A
lower-log.f32N/A
lower-sqrt.f32N/A
sub-negN/A
mul-1-negN/A
lower-/.f32N/A
mul-1-negN/A
sub-negN/A
lower--.f3278.3
Applied rewrites78.3%
if 0.999059975 < (-.f32 #s(literal 1 binary32) u1) Initial program 39.9%
Applied rewrites46.4%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f3290.3
Applied rewrites90.3%
Applied rewrites90.3%
Final simplification86.8%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt u1) (sin (* (+ u2 u2) (PI)))))
\begin{array}{l}
\\
\sqrt{u1} \cdot \sin \left(\left(u2 + u2\right) \cdot \mathsf{PI}\left(\right)\right)
\end{array}
Initial program 55.4%
Applied rewrites36.7%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f3278.2
Applied rewrites78.2%
Applied rewrites78.2%
Final simplification78.2%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* (* (PI) u2) 2.0) (pow (* u1 u1) 0.25)))
\begin{array}{l}
\\
\left(\left(\mathsf{PI}\left(\right) \cdot u2\right) \cdot 2\right) \cdot {\left(u1 \cdot u1\right)}^{0.25}
\end{array}
Initial program 55.4%
Applied rewrites36.7%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f3278.2
Applied rewrites78.2%
Applied rewrites78.2%
Taylor expanded in u2 around 0
Applied rewrites68.6%
Final simplification68.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* (* (PI) u2) 2.0) (sqrt u1)))
\begin{array}{l}
\\
\left(\left(\mathsf{PI}\left(\right) \cdot u2\right) \cdot 2\right) \cdot \sqrt{u1}
\end{array}
Initial program 55.4%
Applied rewrites37.4%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f3278.2
Applied rewrites78.2%
Taylor expanded in u2 around 0
Applied rewrites68.6%
Final simplification68.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* (* (sqrt u1) (PI)) 2.0) u2))
\begin{array}{l}
\\
\left(\left(\sqrt{u1} \cdot \mathsf{PI}\left(\right)\right) \cdot 2\right) \cdot u2
\end{array}
Initial program 55.4%
Applied rewrites35.9%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f3278.2
Applied rewrites78.2%
Applied rewrites78.2%
Taylor expanded in u2 around 0
Applied rewrites68.5%
herbie shell --seed 2024332
(FPCore (cosTheta_i u1 u2)
:name "Beckmann Sample, near normal, slope_y"
:precision binary32
:pre (and (and (and (> cosTheta_i 0.9999) (<= cosTheta_i 1.0)) (and (<= 2.328306437e-10 u1) (<= u1 1.0))) (and (<= 2.328306437e-10 u2) (<= u2 1.0)))
(* (sqrt (- (log (- 1.0 u1)))) (sin (* (* 2.0 (PI)) u2))))