
(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 10 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 (* u2 (PI))) (t_1 (log (- 1.0 u1))))
(if (<= t_1 -0.04500000178813934)
(* (sqrt (- t_1)) (* (* (cos t_0) (sin t_0)) 2.0))
(*
(pow
(pow
(*
(- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0)
u1)
4.0)
0.125)
(sin (* (* 2.0 (PI)) u2))))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := u2 \cdot \mathsf{PI}\left(\right)\\
t_1 := \log \left(1 - u1\right)\\
\mathbf{if}\;t\_1 \leq -0.04500000178813934:\\
\;\;\;\;\sqrt{-t\_1} \cdot \left(\left(\cos t\_0 \cdot \sin t\_0\right) \cdot 2\right)\\
\mathbf{else}:\\
\;\;\;\;{\left({\left(\left(\left(\left(-0.25 \cdot u1 - 0.3333333333333333\right) \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1\right)}^{4}\right)}^{0.125} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\end{array}
\end{array}
if (log.f32 (-.f32 #s(literal 1 binary32) u1)) < -0.0450000018Initial program 97.4%
lift-sin.f32N/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
sin-2N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-cos.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f3297.7
Applied rewrites97.7%
if -0.0450000018 < (log.f32 (-.f32 #s(literal 1 binary32) u1)) Initial program 52.8%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
metadata-evalN/A
distribute-lft-neg-inN/A
lower--.f32N/A
distribute-lft-neg-inN/A
metadata-evalN/A
lower-*.f3298.3
Applied rewrites98.3%
lift-sqrt.f32N/A
pow1/2N/A
metadata-evalN/A
pow-sqrN/A
pow-prod-downN/A
lower-pow.f32N/A
lower-*.f3298.3
Applied rewrites98.3%
lift-pow.f32N/A
metadata-evalN/A
metadata-evalN/A
pow-sqrN/A
pow-prod-downN/A
Applied rewrites98.4%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* u2 (PI)))
(t_1 (log (- 1.0 u1)))
(t_2
(*
(- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0)
u1)))
(if (<= t_1 -0.04500000178813934)
(* (sqrt (- t_1)) (* (* (cos t_0) (sin t_0)) 2.0))
(* (pow (* t_2 t_2) 0.25) (sin (* (* 2.0 (PI)) u2))))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := u2 \cdot \mathsf{PI}\left(\right)\\
t_1 := \log \left(1 - u1\right)\\
t_2 := \left(\left(\left(-0.25 \cdot u1 - 0.3333333333333333\right) \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1\\
\mathbf{if}\;t\_1 \leq -0.04500000178813934:\\
\;\;\;\;\sqrt{-t\_1} \cdot \left(\left(\cos t\_0 \cdot \sin t\_0\right) \cdot 2\right)\\
\mathbf{else}:\\
\;\;\;\;{\left(t\_2 \cdot t\_2\right)}^{0.25} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\end{array}
\end{array}
if (log.f32 (-.f32 #s(literal 1 binary32) u1)) < -0.0450000018Initial program 97.4%
lift-sin.f32N/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
sin-2N/A
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-cos.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f3297.7
Applied rewrites97.7%
if -0.0450000018 < (log.f32 (-.f32 #s(literal 1 binary32) u1)) Initial program 52.8%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
metadata-evalN/A
distribute-lft-neg-inN/A
lower--.f32N/A
distribute-lft-neg-inN/A
metadata-evalN/A
lower-*.f3298.3
Applied rewrites98.3%
lift-sqrt.f32N/A
pow1/2N/A
metadata-evalN/A
pow-sqrN/A
pow-prod-downN/A
lower-pow.f32N/A
lower-*.f3298.3
Applied rewrites98.3%
Final simplification98.2%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (log (- 1.0 u1)))
(t_1
(*
(- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0)
u1))
(t_2 (sin (* (* 2.0 (PI)) u2))))
(if (<= t_0 -0.04500000178813934)
(* (sqrt (- t_0)) t_2)
(* (pow (* t_1 t_1) 0.25) t_2))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \log \left(1 - u1\right)\\
t_1 := \left(\left(\left(-0.25 \cdot u1 - 0.3333333333333333\right) \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1\\
t_2 := \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\mathbf{if}\;t\_0 \leq -0.04500000178813934:\\
\;\;\;\;\sqrt{-t\_0} \cdot t\_2\\
\mathbf{else}:\\
\;\;\;\;{\left(t\_1 \cdot t\_1\right)}^{0.25} \cdot t\_2\\
\end{array}
\end{array}
if (log.f32 (-.f32 #s(literal 1 binary32) u1)) < -0.0450000018Initial program 97.4%
if -0.0450000018 < (log.f32 (-.f32 #s(literal 1 binary32) u1)) Initial program 52.8%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
metadata-evalN/A
distribute-lft-neg-inN/A
lower--.f32N/A
distribute-lft-neg-inN/A
metadata-evalN/A
lower-*.f3298.3
Applied rewrites98.3%
lift-sqrt.f32N/A
pow1/2N/A
metadata-evalN/A
pow-sqrN/A
pow-prod-downN/A
lower-pow.f32N/A
lower-*.f3298.3
Applied rewrites98.3%
Final simplification98.2%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (log (- 1.0 u1))) (t_1 (sin (* (* 2.0 (PI)) u2))))
(if (<= t_0 -0.04500000178813934)
(* (sqrt (- t_0)) t_1)
(*
(sqrt
(-
(*
(- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0)
u1)))
t_1))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \log \left(1 - u1\right)\\
t_1 := \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\mathbf{if}\;t\_0 \leq -0.04500000178813934:\\
\;\;\;\;\sqrt{-t\_0} \cdot t\_1\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\left(\left(\left(-0.25 \cdot u1 - 0.3333333333333333\right) \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1} \cdot t\_1\\
\end{array}
\end{array}
if (log.f32 (-.f32 #s(literal 1 binary32) u1)) < -0.0450000018Initial program 97.4%
if -0.0450000018 < (log.f32 (-.f32 #s(literal 1 binary32) u1)) Initial program 52.8%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
metadata-evalN/A
distribute-lft-neg-inN/A
lower--.f32N/A
distribute-lft-neg-inN/A
metadata-evalN/A
lower-*.f3298.3
Applied rewrites98.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= (log (- 1.0 u1)) -0.07999999821186066)
(* (sqrt (log (/ 1.0 (- 1.0 u1)))) (* (* (PI) u2) 2.0))
(*
(sqrt
(-
(*
(- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0)
u1)))
(sin (* (* 2.0 (PI)) u2)))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\log \left(1 - u1\right) \leq -0.07999999821186066:\\
\;\;\;\;\sqrt{\log \left(\frac{1}{1 - u1}\right)} \cdot \left(\left(\mathsf{PI}\left(\right) \cdot u2\right) \cdot 2\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\left(\left(\left(-0.25 \cdot u1 - 0.3333333333333333\right) \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\end{array}
\end{array}
if (log.f32 (-.f32 #s(literal 1 binary32) u1)) < -0.0799999982Initial program 97.8%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3297.6
Applied rewrites97.6%
Taylor expanded in u2 around 0
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3285.9
Applied rewrites85.9%
if -0.0799999982 < (log.f32 (-.f32 #s(literal 1 binary32) u1)) Initial program 53.9%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
metadata-evalN/A
distribute-lft-neg-inN/A
lower--.f32N/A
distribute-lft-neg-inN/A
metadata-evalN/A
lower-*.f3298.0
Applied rewrites98.0%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= (log (- 1.0 u1)) -0.03200000151991844)
(* (sqrt (log (/ 1.0 (- 1.0 u1)))) (* (* (PI) u2) 2.0))
(*
(sqrt (- (* (- (* (- (* -0.3333333333333333 u1) 0.5) u1) 1.0) u1)))
(sin (* (* 2.0 (PI)) u2)))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\log \left(1 - u1\right) \leq -0.03200000151991844:\\
\;\;\;\;\sqrt{\log \left(\frac{1}{1 - u1}\right)} \cdot \left(\left(\mathsf{PI}\left(\right) \cdot u2\right) \cdot 2\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\left(\left(-0.3333333333333333 \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\end{array}
\end{array}
if (log.f32 (-.f32 #s(literal 1 binary32) u1)) < -0.0320000015Initial program 97.1%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3296.5
Applied rewrites96.5%
Taylor expanded in u2 around 0
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3284.8
Applied rewrites84.8%
if -0.0320000015 < (log.f32 (-.f32 #s(literal 1 binary32) u1)) Initial program 52.0%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
metadata-evalN/A
distribute-lft-neg-inN/A
*-commutativeN/A
distribute-lft-neg-inN/A
lower--.f32N/A
distribute-lft-neg-inN/A
*-commutativeN/A
distribute-lft-neg-inN/A
metadata-evalN/A
lower-*.f3297.9
Applied rewrites97.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (log (- 1.0 u1)) -0.01600000075995922) (* (sqrt (log (/ 1.0 (- 1.0 u1)))) (* (* (PI) u2) 2.0)) (* (sqrt (- (* (- (* -0.5 u1) 1.0) u1))) (sin (* (* 2.0 (PI)) u2)))))
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\log \left(1 - u1\right) \leq -0.01600000075995922:\\
\;\;\;\;\sqrt{\log \left(\frac{1}{1 - u1}\right)} \cdot \left(\left(\mathsf{PI}\left(\right) \cdot u2\right) \cdot 2\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\left(-0.5 \cdot u1 - 1\right) \cdot u1} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\end{array}
\end{array}
if (log.f32 (-.f32 #s(literal 1 binary32) u1)) < -0.0160000008Initial program 96.8%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3295.9
Applied rewrites95.9%
Taylor expanded in u2 around 0
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3284.8
Applied rewrites84.8%
if -0.0160000008 < (log.f32 (-.f32 #s(literal 1 binary32) u1)) Initial program 51.0%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
metadata-evalN/A
distribute-lft-neg-inN/A
*-commutativeN/A
distribute-lft-neg-inN/A
lower--.f32N/A
distribute-lft-neg-inN/A
*-commutativeN/A
distribute-lft-neg-inN/A
metadata-evalN/A
lower-*.f3296.0
Applied rewrites96.0%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (log (- 1.0 u1)) -0.0003000000142492354) (* (sqrt (log (/ 1.0 (- 1.0 u1)))) (* (* (PI) u2) 2.0)) (* (sqrt u1) (sin (* (* 2.0 (PI)) u2)))))
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\log \left(1 - u1\right) \leq -0.0003000000142492354:\\
\;\;\;\;\sqrt{\log \left(\frac{1}{1 - u1}\right)} \cdot \left(\left(\mathsf{PI}\left(\right) \cdot u2\right) \cdot 2\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\end{array}
\end{array}
if (log.f32 (-.f32 #s(literal 1 binary32) u1)) < -3.00000014e-4Initial program 91.0%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3288.9
Applied rewrites88.9%
Taylor expanded in u2 around 0
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3276.4
Applied rewrites76.4%
if -3.00000014e-4 < (log.f32 (-.f32 #s(literal 1 binary32) u1)) Initial program 42.3%
lift-sqrt.f32N/A
pow1/2N/A
sqr-powN/A
pow2N/A
lower-pow.f32N/A
lower-pow.f32N/A
lift-log.f32N/A
lift--.f32N/A
*-lft-identityN/A
fp-cancel-sub-sign-invN/A
distribute-lft-neg-inN/A
*-lft-identityN/A
lower-log1p.f32N/A
lower-neg.f32N/A
metadata-eval15.1
Applied rewrites14.2%
Taylor expanded in u1 around 0
lower-sqrt.f3290.3
Applied rewrites90.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt u1) (sin (* (* 2.0 (PI)) u2))))
\begin{array}{l}
\\
\sqrt{u1} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
Initial program 58.9%
lift-sqrt.f32N/A
pow1/2N/A
sqr-powN/A
pow2N/A
lower-pow.f32N/A
lower-pow.f32N/A
lift-log.f32N/A
lift--.f32N/A
*-lft-identityN/A
fp-cancel-sub-sign-invN/A
distribute-lft-neg-inN/A
*-lft-identityN/A
lower-log1p.f32N/A
lower-neg.f32N/A
metadata-eval14.4
Applied rewrites14.5%
Taylor expanded in u1 around 0
lower-sqrt.f3276.4
Applied rewrites76.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt u1) (* (* (PI) u2) 2.0)))
\begin{array}{l}
\\
\sqrt{u1} \cdot \left(\left(\mathsf{PI}\left(\right) \cdot u2\right) \cdot 2\right)
\end{array}
Initial program 58.9%
lift-sqrt.f32N/A
pow1/2N/A
sqr-powN/A
pow2N/A
lower-pow.f32N/A
lower-pow.f32N/A
lift-log.f32N/A
lift--.f32N/A
*-lft-identityN/A
fp-cancel-sub-sign-invN/A
distribute-lft-neg-inN/A
*-lft-identityN/A
lower-log1p.f32N/A
lower-neg.f32N/A
metadata-eval14.4
Applied rewrites16.4%
Taylor expanded in u1 around 0
lower-sqrt.f3276.4
Applied rewrites76.4%
Taylor expanded in u2 around 0
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f3264.5
Applied rewrites64.5%
herbie shell --seed 2024347
(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))))