
(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 (* (sqrt (+ (- (log1p (* (- u1) u1))) (log1p u1))) (sin (* (* 2.0 (PI)) u2))))
\begin{array}{l}
\\
\sqrt{\left(-\mathsf{log1p}\left(\left(-u1\right) \cdot u1\right)\right) + \mathsf{log1p}\left(u1\right)} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
Initial program 63.1%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lift--.f32N/A
flip--N/A
associate-/r/N/A
log-prodN/A
lower-+.f32N/A
log-recN/A
lower-neg.f32N/A
metadata-evalN/A
fp-cancel-sub-sign-invN/A
lower-log1p.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-log1p.f3298.4
Applied rewrites98.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log1p (- u1)))) (sin (* (* 2.0 (PI)) u2))))
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
Initial program 63.1%
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.f3298.4
Applied rewrites98.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (* (fma (fma (fma 0.25 u1 0.3333333333333333) u1 0.5) u1 1.0) u1)) (sin (* (* 2.0 (PI)) u2))))
\begin{array}{l}
\\
\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.25, u1, 0.3333333333333333\right), u1, 0.5\right), u1, 1\right) \cdot u1} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
Initial program 63.1%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
+-commutativeN/A
lower-fma.f3294.0
Applied rewrites94.0%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (* (fma (fma 0.3333333333333333 u1 0.5) u1 1.0) u1)) (sin (* (* 2.0 (PI)) u2))))
\begin{array}{l}
\\
\sqrt{\mathsf{fma}\left(\mathsf{fma}\left(0.3333333333333333, u1, 0.5\right), u1, 1\right) \cdot u1} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
Initial program 63.1%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
+-commutativeN/A
lower-fma.f3292.3
Applied rewrites92.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (* (fma 0.5 u1 1.0) u1)) (sin (* (* 2.0 (PI)) u2))))
\begin{array}{l}
\\
\sqrt{\mathsf{fma}\left(0.5, u1, 1\right) \cdot u1} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
Initial program 63.1%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
+-commutativeN/A
lower-fma.f3288.8
Applied rewrites88.8%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= u2 0.00139999995008111)
(fma
(* (* 2.0 (sqrt u1)) u2)
(PI)
(*
(*
(* (PI) u2)
(fma 0.5 (sqrt (/ 1.0 u1)) (* 0.3333333333333333 (sqrt u1))))
(* u1 u1)))
(* (sqrt u1) (sin (* (* 2.0 (PI)) u2)))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \leq 0.00139999995008111:\\
\;\;\;\;\mathsf{fma}\left(\left(2 \cdot \sqrt{u1}\right) \cdot u2, \mathsf{PI}\left(\right), \left(\left(\mathsf{PI}\left(\right) \cdot u2\right) \cdot \mathsf{fma}\left(0.5, \sqrt{\frac{1}{u1}}, 0.3333333333333333 \cdot \sqrt{u1}\right)\right) \cdot \left(u1 \cdot u1\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \sin \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\end{array}
\end{array}
if u2 < 0.00139999995Initial program 64.2%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lift--.f32N/A
flip--N/A
associate-/r/N/A
log-prodN/A
lower-+.f32N/A
log-recN/A
lower-neg.f32N/A
metadata-evalN/A
fp-cancel-sub-sign-invN/A
lower-log1p.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-log1p.f3298.6
Applied rewrites98.6%
Taylor expanded in u2 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
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f32N/A
lower--.f32N/A
lower-log1p.f32N/A
mul-1-negN/A
Applied rewrites96.8%
Taylor expanded in u1 around 0
Applied rewrites74.3%
Taylor expanded in u1 around 0
Applied rewrites90.5%
if 0.00139999995 < u2 Initial program 60.4%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lift--.f32N/A
flip--N/A
associate-/r/N/A
log-prodN/A
lower-+.f32N/A
log-recN/A
lower-neg.f32N/A
metadata-evalN/A
fp-cancel-sub-sign-invN/A
lower-log1p.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-log1p.f3298.1
Applied rewrites98.1%
Taylor expanded in u1 around 0
lower-sqrt.f3276.0
Applied rewrites76.0%
(FPCore (cosTheta_i u1 u2) :precision binary32 (fma (* (* 2.0 (sqrt u1)) u2) (PI) (* (* (* (PI) u2) (fma 0.5 (sqrt (/ 1.0 u1)) (* 0.3333333333333333 (sqrt u1)))) (* u1 u1))))
\begin{array}{l}
\\
\mathsf{fma}\left(\left(2 \cdot \sqrt{u1}\right) \cdot u2, \mathsf{PI}\left(\right), \left(\left(\mathsf{PI}\left(\right) \cdot u2\right) \cdot \mathsf{fma}\left(0.5, \sqrt{\frac{1}{u1}}, 0.3333333333333333 \cdot \sqrt{u1}\right)\right) \cdot \left(u1 \cdot u1\right)\right)
\end{array}
Initial program 63.1%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lift--.f32N/A
flip--N/A
associate-/r/N/A
log-prodN/A
lower-+.f32N/A
log-recN/A
lower-neg.f32N/A
metadata-evalN/A
fp-cancel-sub-sign-invN/A
lower-log1p.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-log1p.f3298.4
Applied rewrites98.4%
Taylor expanded in u2 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
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f32N/A
lower--.f32N/A
lower-log1p.f32N/A
mul-1-negN/A
Applied rewrites82.0%
Taylor expanded in u1 around 0
Applied rewrites65.7%
Taylor expanded in u1 around 0
Applied rewrites77.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* (* 2.0 (sqrt u1)) (PI)) u2))
\begin{array}{l}
\\
\left(\left(2 \cdot \sqrt{u1}\right) \cdot \mathsf{PI}\left(\right)\right) \cdot u2
\end{array}
Initial program 63.1%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lift--.f32N/A
flip--N/A
associate-/r/N/A
log-prodN/A
lower-+.f32N/A
log-recN/A
lower-neg.f32N/A
metadata-evalN/A
fp-cancel-sub-sign-invN/A
lower-log1p.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-log1p.f3298.4
Applied rewrites98.4%
Taylor expanded in u2 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
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f32N/A
lower--.f32N/A
lower-log1p.f32N/A
mul-1-negN/A
Applied rewrites82.0%
Taylor expanded in u1 around 0
Applied rewrites65.7%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* (* 2.0 (sqrt u1)) u2) (PI)))
\begin{array}{l}
\\
\left(\left(2 \cdot \sqrt{u1}\right) \cdot u2\right) \cdot \mathsf{PI}\left(\right)
\end{array}
Initial program 63.1%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lift--.f32N/A
flip--N/A
associate-/r/N/A
log-prodN/A
lower-+.f32N/A
log-recN/A
lower-neg.f32N/A
metadata-evalN/A
fp-cancel-sub-sign-invN/A
lower-log1p.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-log1p.f3298.4
Applied rewrites98.4%
Taylor expanded in u2 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
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f32N/A
lower--.f32N/A
lower-log1p.f32N/A
mul-1-negN/A
Applied rewrites82.0%
Taylor expanded in u1 around 0
Applied rewrites65.7%
Taylor expanded in u1 around 0
Applied rewrites65.7%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (* (sqrt u1) 2.0) (* u2 (PI))))
\begin{array}{l}
\\
\left(\sqrt{u1} \cdot 2\right) \cdot \left(u2 \cdot \mathsf{PI}\left(\right)\right)
\end{array}
Initial program 63.1%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lift--.f32N/A
flip--N/A
associate-/r/N/A
log-prodN/A
lower-+.f32N/A
log-recN/A
lower-neg.f32N/A
metadata-evalN/A
fp-cancel-sub-sign-invN/A
lower-log1p.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-log1p.f3298.4
Applied rewrites98.4%
Taylor expanded in u2 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
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-PI.f32N/A
lower-sqrt.f32N/A
lower--.f32N/A
lower-log1p.f32N/A
mul-1-negN/A
Applied rewrites82.0%
Taylor expanded in u1 around 0
Applied rewrites65.7%
Applied rewrites65.7%
herbie shell --seed 2025006
(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))))