
(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 9 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
(let* ((t_0 (cbrt (PI))) (t_1 (pow t_0 2.0)))
(if (<= (- 1.0 u1) 0.9998239874839783)
(*
(cos (* (cbrt t_0) (* (cbrt t_1) (* (* u2 t_1) 2.0))))
(sqrt (- (log (- 1.0 u1)))))
(*
(sqrt u1)
(cos
(*
(* (* (pow (PI) 0.2916666666666667) u2) 2.0)
(pow (PI) 0.7083333333333334)))))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt[3]{\mathsf{PI}\left(\right)}\\
t_1 := {t\_0}^{2}\\
\mathbf{if}\;1 - u1 \leq 0.9998239874839783:\\
\;\;\;\;\cos \left(\sqrt[3]{t\_0} \cdot \left(\sqrt[3]{t\_1} \cdot \left(\left(u2 \cdot t\_1\right) \cdot 2\right)\right)\right) \cdot \sqrt{-\log \left(1 - u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \cos \left(\left(\left({\mathsf{PI}\left(\right)}^{0.2916666666666667} \cdot u2\right) \cdot 2\right) \cdot {\mathsf{PI}\left(\right)}^{0.7083333333333334}\right)\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u1) < 0.999823987Initial program 89.5%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lift-PI.f32N/A
add-sqr-sqrtN/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lift-PI.f32N/A
lower-sqrt.f32N/A
lift-PI.f32N/A
lower-sqrt.f3289.5
Applied rewrites89.5%
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
lift-sqrt.f32N/A
lift-sqrt.f32N/A
rem-square-sqrtN/A
rem-cube-cbrtN/A
lift-cbrt.f32N/A
pow3N/A
unpow2N/A
lift-pow.f32N/A
associate-*r*N/A
unpow1N/A
metadata-evalN/A
pow-powN/A
pow3N/A
Applied rewrites89.5%
if 0.999823987 < (-.f32 #s(literal 1 binary32) u1) Initial program 38.3%
Taylor expanded in u1 around 0
*-commutativeN/A
unpow2N/A
rem-square-sqrtN/A
mul-1-negN/A
lower-neg.f32N/A
lower-sqrt.f323.6
Applied rewrites3.6%
Applied rewrites92.2%
lift-*.f32N/A
lift-*.f32N/A
associate-*r*N/A
*-commutativeN/A
rem-square-sqrtN/A
lift-sqrt.f32N/A
lift-sqrt.f32N/A
associate-*l*N/A
lift-*.f32N/A
associate-*r*N/A
lift-*.f32N/A
lift-sqrt.f32N/A
pow1/2N/A
metadata-evalN/A
pow-prod-upN/A
pow1/3N/A
lift-cbrt.f32N/A
lift-pow.f32N/A
Applied rewrites92.2%
lift-*.f32N/A
lift-*.f32N/A
lift-pow.f32N/A
sqr-powN/A
associate-*l*N/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
lift-pow.f32N/A
pow-prod-upN/A
lower-pow.f32N/A
metadata-evalN/A
metadata-evalN/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
Applied rewrites92.2%
Final simplification91.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= (- 1.0 u1) 0.9998239874839783)
(*
(cos (* (* (* u2 2.0) (cbrt (* (PI) (PI)))) (cbrt (PI))))
(sqrt (- (log (- 1.0 u1)))))
(*
(sqrt u1)
(cos
(*
(* (* (pow (PI) 0.2916666666666667) u2) 2.0)
(pow (PI) 0.7083333333333334))))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u1 \leq 0.9998239874839783:\\
\;\;\;\;\cos \left(\left(\left(u2 \cdot 2\right) \cdot \sqrt[3]{\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)}\right) \cdot \sqrt[3]{\mathsf{PI}\left(\right)}\right) \cdot \sqrt{-\log \left(1 - u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \cos \left(\left(\left({\mathsf{PI}\left(\right)}^{0.2916666666666667} \cdot u2\right) \cdot 2\right) \cdot {\mathsf{PI}\left(\right)}^{0.7083333333333334}\right)\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u1) < 0.999823987Initial program 89.5%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lift-PI.f32N/A
add-sqr-sqrtN/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lift-PI.f32N/A
lower-sqrt.f32N/A
lift-PI.f32N/A
lower-sqrt.f3289.5
Applied rewrites89.5%
lift-*.f32N/A
*-commutativeN/A
lift-sqrt.f32N/A
pow1/2N/A
metadata-evalN/A
metadata-evalN/A
pow-prod-upN/A
pow1/3N/A
lift-cbrt.f32N/A
sqrt-pow2N/A
lift-sqrt.f32N/A
associate-*l*N/A
lower-*.f32N/A
lower-*.f32N/A
lift-sqrt.f32N/A
sqrt-pow2N/A
lower-pow.f32N/A
metadata-eval89.5
lift-*.f32N/A
*-commutativeN/A
Applied rewrites89.5%
Taylor expanded in u2 around 0
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-cbrt.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3289.5
Applied rewrites89.5%
if 0.999823987 < (-.f32 #s(literal 1 binary32) u1) Initial program 38.3%
Taylor expanded in u1 around 0
*-commutativeN/A
unpow2N/A
rem-square-sqrtN/A
mul-1-negN/A
lower-neg.f32N/A
lower-sqrt.f323.6
Applied rewrites3.6%
Applied rewrites92.2%
lift-*.f32N/A
lift-*.f32N/A
associate-*r*N/A
*-commutativeN/A
rem-square-sqrtN/A
lift-sqrt.f32N/A
lift-sqrt.f32N/A
associate-*l*N/A
lift-*.f32N/A
associate-*r*N/A
lift-*.f32N/A
lift-sqrt.f32N/A
pow1/2N/A
metadata-evalN/A
pow-prod-upN/A
pow1/3N/A
lift-cbrt.f32N/A
lift-pow.f32N/A
Applied rewrites92.2%
lift-*.f32N/A
lift-*.f32N/A
lift-pow.f32N/A
sqr-powN/A
associate-*l*N/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
lift-pow.f32N/A
pow-prod-upN/A
lower-pow.f32N/A
metadata-evalN/A
metadata-evalN/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
Applied rewrites92.2%
Final simplification91.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (- (log (- 1.0 u1)))) (t_1 (sqrt (PI))))
(if (<= t_0 0.00017600000137463212)
(* (cos (* (* 2.0 (PI)) u2)) (sqrt u1))
(* (cos (* (* t_1 (* u2 2.0)) t_1)) (sqrt t_0)))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := -\log \left(1 - u1\right)\\
t_1 := \sqrt{\mathsf{PI}\left(\right)}\\
\mathbf{if}\;t\_0 \leq 0.00017600000137463212:\\
\;\;\;\;\cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \cdot \sqrt{u1}\\
\mathbf{else}:\\
\;\;\;\;\cos \left(\left(t\_1 \cdot \left(u2 \cdot 2\right)\right) \cdot t\_1\right) \cdot \sqrt{t\_0}\\
\end{array}
\end{array}
if (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1))) < 1.76000001e-4Initial program 38.3%
Taylor expanded in u1 around 0
*-commutativeN/A
unpow2N/A
rem-square-sqrtN/A
mul-1-negN/A
lower-neg.f32N/A
lower-sqrt.f323.6
Applied rewrites3.6%
Applied rewrites92.2%
if 1.76000001e-4 < (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1))) Initial program 89.5%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lift-PI.f32N/A
add-sqr-sqrtN/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lift-PI.f32N/A
lower-sqrt.f32N/A
lift-PI.f32N/A
lower-sqrt.f3289.5
Applied rewrites89.5%
Final simplification91.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (sqrt (PI))))
(if (<= (- 1.0 u1) 0.9998239874839783)
(* (cos (* (* t_0 (* u2 2.0)) t_0)) (sqrt (- (log (- 1.0 u1)))))
(*
(sqrt u1)
(cos
(*
(* (* (pow (PI) 0.2916666666666667) u2) 2.0)
(pow (PI) 0.7083333333333334)))))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{\mathsf{PI}\left(\right)}\\
\mathbf{if}\;1 - u1 \leq 0.9998239874839783:\\
\;\;\;\;\cos \left(\left(t\_0 \cdot \left(u2 \cdot 2\right)\right) \cdot t\_0\right) \cdot \sqrt{-\log \left(1 - u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \cos \left(\left(\left({\mathsf{PI}\left(\right)}^{0.2916666666666667} \cdot u2\right) \cdot 2\right) \cdot {\mathsf{PI}\left(\right)}^{0.7083333333333334}\right)\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u1) < 0.999823987Initial program 89.5%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lift-PI.f32N/A
add-sqr-sqrtN/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lift-PI.f32N/A
lower-sqrt.f32N/A
lift-PI.f32N/A
lower-sqrt.f3289.5
Applied rewrites89.5%
if 0.999823987 < (-.f32 #s(literal 1 binary32) u1) Initial program 38.3%
Taylor expanded in u1 around 0
*-commutativeN/A
unpow2N/A
rem-square-sqrtN/A
mul-1-negN/A
lower-neg.f32N/A
lower-sqrt.f323.6
Applied rewrites3.6%
Applied rewrites92.2%
lift-*.f32N/A
lift-*.f32N/A
associate-*r*N/A
*-commutativeN/A
rem-square-sqrtN/A
lift-sqrt.f32N/A
lift-sqrt.f32N/A
associate-*l*N/A
lift-*.f32N/A
associate-*r*N/A
lift-*.f32N/A
lift-sqrt.f32N/A
pow1/2N/A
metadata-evalN/A
pow-prod-upN/A
pow1/3N/A
lift-cbrt.f32N/A
lift-pow.f32N/A
Applied rewrites92.2%
lift-*.f32N/A
lift-*.f32N/A
lift-pow.f32N/A
sqr-powN/A
associate-*l*N/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
lift-pow.f32N/A
pow-prod-upN/A
lower-pow.f32N/A
metadata-evalN/A
metadata-evalN/A
*-commutativeN/A
lift-*.f32N/A
*-commutativeN/A
associate-*r*N/A
lower-*.f32N/A
Applied rewrites92.2%
Final simplification91.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (let* ((t_0 (- (log (- 1.0 u1)))) (t_1 (cos (* (* 2.0 (PI)) u2)))) (if (<= t_0 0.00017600000137463212) (* t_1 (sqrt u1)) (* t_1 (sqrt t_0)))))
\begin{array}{l}
\\
\begin{array}{l}
t_0 := -\log \left(1 - u1\right)\\
t_1 := \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\mathbf{if}\;t\_0 \leq 0.00017600000137463212:\\
\;\;\;\;t\_1 \cdot \sqrt{u1}\\
\mathbf{else}:\\
\;\;\;\;t\_1 \cdot \sqrt{t\_0}\\
\end{array}
\end{array}
if (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1))) < 1.76000001e-4Initial program 38.3%
Taylor expanded in u1 around 0
*-commutativeN/A
unpow2N/A
rem-square-sqrtN/A
mul-1-negN/A
lower-neg.f32N/A
lower-sqrt.f323.6
Applied rewrites3.6%
Applied rewrites92.2%
if 1.76000001e-4 < (neg.f32 (log.f32 (-.f32 #s(literal 1 binary32) u1))) Initial program 89.5%
Final simplification91.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (cos (* (* 2.0 (PI)) u2)) (sqrt u1)))
\begin{array}{l}
\\
\cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \cdot \sqrt{u1}
\end{array}
Initial program 56.1%
Taylor expanded in u1 around 0
*-commutativeN/A
unpow2N/A
rem-square-sqrtN/A
mul-1-negN/A
lower-neg.f32N/A
lower-sqrt.f323.5
Applied rewrites3.5%
Applied rewrites78.5%
Final simplification78.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (pow (* u1 u1) 0.25) 1.0))
float code(float cosTheta_i, float u1, float u2) {
return powf((u1 * u1), 0.25f) * 1.0f;
}
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 = ((u1 * u1) ** 0.25e0) * 1.0e0
end function
function code(cosTheta_i, u1, u2) return Float32((Float32(u1 * u1) ^ Float32(0.25)) * Float32(1.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = ((u1 * u1) ^ single(0.25)) * single(1.0); end
\begin{array}{l}
\\
{\left(u1 \cdot u1\right)}^{0.25} \cdot 1
\end{array}
Initial program 56.1%
Taylor expanded in u1 around 0
*-commutativeN/A
unpow2N/A
rem-square-sqrtN/A
mul-1-negN/A
lower-neg.f32N/A
lower-sqrt.f323.5
Applied rewrites3.5%
Applied rewrites78.5%
Taylor expanded in u2 around 0
Applied rewrites69.9%
Applied rewrites69.9%
Final simplification69.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (/ -1.0 (/ -1.0 (sqrt u1))) 1.0))
float code(float cosTheta_i, float u1, float u2) {
return (-1.0f / (-1.0f / sqrtf(u1))) * 1.0f;
}
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 = ((-1.0e0) / ((-1.0e0) / sqrt(u1))) * 1.0e0
end function
function code(cosTheta_i, u1, u2) return Float32(Float32(Float32(-1.0) / Float32(Float32(-1.0) / sqrt(u1))) * Float32(1.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = (single(-1.0) / (single(-1.0) / sqrt(u1))) * single(1.0); end
\begin{array}{l}
\\
\frac{-1}{\frac{-1}{\sqrt{u1}}} \cdot 1
\end{array}
Initial program 56.1%
Taylor expanded in u1 around 0
*-commutativeN/A
unpow2N/A
rem-square-sqrtN/A
mul-1-negN/A
lower-neg.f32N/A
lower-sqrt.f323.5
Applied rewrites3.5%
Applied rewrites78.5%
Taylor expanded in u2 around 0
Applied rewrites69.9%
Applied rewrites69.9%
Final simplification69.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* 1.0 (sqrt u1)))
float code(float cosTheta_i, float u1, float u2) {
return 1.0f * 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 = 1.0e0 * sqrt(u1)
end function
function code(cosTheta_i, u1, u2) return Float32(Float32(1.0) * sqrt(u1)) end
function tmp = code(cosTheta_i, u1, u2) tmp = single(1.0) * sqrt(u1); end
\begin{array}{l}
\\
1 \cdot \sqrt{u1}
\end{array}
Initial program 56.1%
Taylor expanded in u1 around 0
*-commutativeN/A
unpow2N/A
rem-square-sqrtN/A
mul-1-negN/A
lower-neg.f32N/A
lower-sqrt.f323.5
Applied rewrites3.5%
Applied rewrites78.5%
Taylor expanded in u2 around 0
Applied rewrites69.9%
herbie shell --seed 2024308
(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))))