
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 (PI)) u2))))
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \cos \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)))) (cos (* (* 2.0 (PI)) u2))))
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= (- 1.0 u1) 0.9580000042915344)
(* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 (PI)) u2)))
(*
(sqrt
(-
(*
(- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0)
u1)))
(sin (+ (- (* (- u2) (PI)) (* u2 (PI))) (/ (PI) 2.0))))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u1 \leq 0.9580000042915344:\\
\;\;\;\;\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\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(\left(-u2\right) \cdot \mathsf{PI}\left(\right) - u2 \cdot \mathsf{PI}\left(\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right)\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u1) < 0.958000004Initial program 98.4%
if 0.958000004 < (-.f32 #s(literal 1 binary32) u1) Initial program 45.2%
lift-cos.f32N/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
cos-2N/A
lower--.f32N/A
pow2N/A
lower-pow.f32N/A
lower-cos.f32N/A
*-commutativeN/A
lower-*.f32N/A
pow2N/A
lower-pow.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f3245.2
Applied rewrites45.2%
lift--.f32N/A
lift-pow.f32N/A
unpow2N/A
fp-cancel-sub-sign-invN/A
lift-pow.f32N/A
unpow2N/A
lift-cos.f32N/A
cos-neg-revN/A
lift-cos.f32N/A
lift-sin.f32N/A
sin-neg-revN/A
lift-sin.f32N/A
cos-diffN/A
sin-+PI/2-revN/A
Applied rewrites45.2%
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
lower--.f32N/A
lower-*.f3298.9
Applied rewrites98.9%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<=
(* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 (PI)) u2)))
0.08460000157356262)
(* (sqrt (- (* (- (* -0.5 u1) 1.0) u1))) (cos (* (PI) (+ u2 u2))))
(sqrt (log (/ 1.0 (- 1.0 u1))))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \leq 0.08460000157356262:\\
\;\;\;\;\sqrt{-\left(-0.5 \cdot u1 - 1\right) \cdot u1} \cdot \cos \left(\mathsf{PI}\left(\right) \cdot \left(u2 + u2\right)\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\log \left(\frac{1}{1 - u1}\right)}\\
\end{array}
\end{array}
if (*.f32 (sqrt.f32 (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1)))) (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2))) < 0.0846000016Initial program 43.2%
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-*.f3296.9
Applied rewrites96.9%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
count-2-revN/A
distribute-rgt-inN/A
*-commutativeN/A
lift-*.f32N/A
fp-cancel-sign-sub-invN/A
fp-cancel-sub-sign-invN/A
lift-*.f32N/A
lower-fma.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-neg.f3281.0
Applied rewrites81.0%
lift-fma.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-neg.f32N/A
lift-neg.f32N/A
remove-double-negN/A
distribute-lft-outN/A
lower-*.f32N/A
lower-+.f3296.9
Applied rewrites96.9%
if 0.0846000016 < (*.f32 (sqrt.f32 (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1)))) (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2))) Initial program 96.1%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3295.4
Applied rewrites95.4%
Taylor expanded in u2 around 0
lower-sqrt.f32N/A
log-recN/A
lower-neg.f32N/A
lower-log.f32N/A
lower--.f3277.6
Applied rewrites77.6%
Applied rewrites77.7%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (cos (* (* 2.0 (PI)) u2))))
(if (<= t_0 0.9999994039535522)
(* (sqrt u1) t_0)
(sqrt
(-
(*
(- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0)
u1))))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\mathbf{if}\;t\_0 \leq 0.9999994039535522:\\
\;\;\;\;\sqrt{u1} \cdot t\_0\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\left(\left(\left(-0.25 \cdot u1 - 0.3333333333333333\right) \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1}\\
\end{array}
\end{array}
if (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) < 0.999999404Initial program 52.8%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3250.5
Applied rewrites50.5%
Taylor expanded in u1 around 0
lower-sqrt.f3277.7
Applied rewrites77.7%
if 0.999999404 < (cos.f32 (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2)) Initial program 50.7%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3248.5
Applied rewrites48.5%
Taylor expanded in u2 around 0
lower-sqrt.f32N/A
log-recN/A
lower-neg.f32N/A
lower-log.f32N/A
lower--.f3250.7
Applied rewrites50.7%
Taylor expanded in u1 around 0
Applied rewrites96.2%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(*
(sqrt
(-
(* (- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0) u1)))
(sin (+ (- (* (- u2) (PI)) (* u2 (PI))) (/ (PI) 2.0)))))\begin{array}{l}
\\
\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(\left(-u2\right) \cdot \mathsf{PI}\left(\right) - u2 \cdot \mathsf{PI}\left(\right)\right) + \frac{\mathsf{PI}\left(\right)}{2}\right)
\end{array}
Initial program 51.4%
lift-cos.f32N/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
cos-2N/A
lower--.f32N/A
pow2N/A
lower-pow.f32N/A
lower-cos.f32N/A
*-commutativeN/A
lower-*.f32N/A
pow2N/A
lower-pow.f32N/A
lower-sin.f32N/A
*-commutativeN/A
lower-*.f3251.4
Applied rewrites51.4%
lift--.f32N/A
lift-pow.f32N/A
unpow2N/A
fp-cancel-sub-sign-invN/A
lift-pow.f32N/A
unpow2N/A
lift-cos.f32N/A
cos-neg-revN/A
lift-cos.f32N/A
lift-sin.f32N/A
sin-neg-revN/A
lift-sin.f32N/A
cos-diffN/A
sin-+PI/2-revN/A
Applied rewrites51.4%
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
lower--.f32N/A
lower-*.f3294.9
Applied rewrites94.9%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(*
(sqrt
(-
(* (- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0) u1)))
(cos (* (* 2.0 (PI)) u2))))\begin{array}{l}
\\
\sqrt{-\left(\left(\left(-0.25 \cdot u1 - 0.3333333333333333\right) \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
Initial program 51.4%
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-*.f3294.9
Applied rewrites94.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (* (- (* (- (* -0.3333333333333333 u1) 0.5) u1) 1.0) u1))) (cos (* (* 2.0 (PI)) u2))))
\begin{array}{l}
\\
\sqrt{-\left(\left(-0.3333333333333333 \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
Initial program 51.4%
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-*.f3293.6
Applied rewrites93.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (- (* (- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0) u1))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-(((((((-0.25f * u1) - 0.3333333333333333f) * u1) - 0.5f) * u1) - 1.0f) * u1));
}
real(4) function code(costheta_i, u1, u2)
real(4), intent (in) :: costheta_i
real(4), intent (in) :: u1
real(4), intent (in) :: u2
code = sqrt(-((((((((-0.25e0) * u1) - 0.3333333333333333e0) * u1) - 0.5e0) * u1) - 1.0e0) * u1))
end function
function code(cosTheta_i, u1, u2) return sqrt(Float32(-Float32(Float32(Float32(Float32(Float32(Float32(Float32(Float32(-0.25) * u1) - Float32(0.3333333333333333)) * u1) - Float32(0.5)) * u1) - Float32(1.0)) * u1))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-(((((((single(-0.25) * u1) - single(0.3333333333333333)) * u1) - single(0.5)) * u1) - single(1.0)) * u1)); end
\begin{array}{l}
\\
\sqrt{-\left(\left(\left(-0.25 \cdot u1 - 0.3333333333333333\right) \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1}
\end{array}
Initial program 51.4%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3249.2
Applied rewrites49.2%
Taylor expanded in u2 around 0
lower-sqrt.f32N/A
log-recN/A
lower-neg.f32N/A
lower-log.f32N/A
lower--.f3243.9
Applied rewrites43.9%
Taylor expanded in u1 around 0
Applied rewrites79.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (- (* (- (* (- (* -0.3333333333333333 u1) 0.5) u1) 1.0) u1))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-(((((-0.3333333333333333f * u1) - 0.5f) * u1) - 1.0f) * u1));
}
real(4) function code(costheta_i, u1, u2)
real(4), intent (in) :: costheta_i
real(4), intent (in) :: u1
real(4), intent (in) :: u2
code = sqrt(-((((((-0.3333333333333333e0) * u1) - 0.5e0) * u1) - 1.0e0) * u1))
end function
function code(cosTheta_i, u1, u2) return sqrt(Float32(-Float32(Float32(Float32(Float32(Float32(Float32(-0.3333333333333333) * u1) - Float32(0.5)) * u1) - Float32(1.0)) * u1))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-(((((single(-0.3333333333333333) * u1) - single(0.5)) * u1) - single(1.0)) * u1)); end
\begin{array}{l}
\\
\sqrt{-\left(\left(-0.3333333333333333 \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1}
\end{array}
Initial program 51.4%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3249.2
Applied rewrites49.2%
Taylor expanded in u2 around 0
lower-sqrt.f32N/A
log-recN/A
lower-neg.f32N/A
lower-log.f32N/A
lower--.f3243.9
Applied rewrites43.9%
Taylor expanded in u1 around 0
Applied rewrites78.6%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (- (* (- (* -0.5 u1) 1.0) u1))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-(((-0.5f * u1) - 1.0f) * u1));
}
real(4) function code(costheta_i, u1, u2)
real(4), intent (in) :: costheta_i
real(4), intent (in) :: u1
real(4), intent (in) :: u2
code = sqrt(-((((-0.5e0) * u1) - 1.0e0) * u1))
end function
function code(cosTheta_i, u1, u2) return sqrt(Float32(-Float32(Float32(Float32(Float32(-0.5) * u1) - Float32(1.0)) * u1))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-(((single(-0.5) * u1) - single(1.0)) * u1)); end
\begin{array}{l}
\\
\sqrt{-\left(-0.5 \cdot u1 - 1\right) \cdot u1}
\end{array}
Initial program 51.4%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3249.2
Applied rewrites49.2%
Taylor expanded in u2 around 0
lower-sqrt.f32N/A
log-recN/A
lower-neg.f32N/A
lower-log.f32N/A
lower--.f3243.9
Applied rewrites43.9%
Taylor expanded in u1 around 0
Applied rewrites76.4%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt u1))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(u1);
}
real(4) function code(costheta_i, u1, u2)
real(4), intent (in) :: costheta_i
real(4), intent (in) :: u1
real(4), intent (in) :: u2
code = sqrt(u1)
end function
function code(cosTheta_i, u1, u2) return sqrt(u1) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(u1); end
\begin{array}{l}
\\
\sqrt{u1}
\end{array}
Initial program 51.4%
lift-neg.f32N/A
lift-log.f32N/A
neg-logN/A
lower-log.f32N/A
lower-/.f3249.2
Applied rewrites49.2%
Taylor expanded in u2 around 0
lower-sqrt.f32N/A
log-recN/A
lower-neg.f32N/A
lower-log.f32N/A
lower--.f3243.9
Applied rewrites43.9%
Applied rewrites41.4%
Taylor expanded in u1 around 0
Applied rewrites69.0%
herbie shell --seed 2024326
(FPCore (cosTheta_i u1 u2)
:name "Beckmann Sample, near normal, slope_x"
: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)))) (cos (* (* 2.0 (PI)) u2))))