
(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 11 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 (cos (* (+ (PI) (PI)) u2))))
(if (<= u1 0.03999999910593033)
(*
(sqrt
(-
(*
(- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0)
u1)))
t_0)
(* (sqrt (- (log (- 1.0 u1)))) t_0))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \cos \left(\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\mathbf{if}\;u1 \leq 0.03999999910593033:\\
\;\;\;\;\sqrt{-\left(\left(\left(-0.25 \cdot u1 - 0.3333333333333333\right) \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1} \cdot t\_0\\
\mathbf{else}:\\
\;\;\;\;\sqrt{-\log \left(1 - u1\right)} \cdot t\_0\\
\end{array}
\end{array}
if u1 < 0.0399999991Initial program 53.8%
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-*.f3298.9
Applied rewrites98.9%
lift-PI.f32N/A
add-cube-cbrtN/A
pow3N/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-cbrt.f3298.7
Applied rewrites98.7%
lift-*.f32N/A
lift-pow.f32N/A
lift-cbrt.f32N/A
rem-cube-cbrtN/A
lift-PI.f32N/A
lift-PI.f32N/A
count-2-revN/A
lower-+.f3298.9
Applied rewrites98.9%
if 0.0399999991 < u1 Initial program 97.9%
lift-*.f32N/A
count-2-revN/A
lower-+.f3297.9
Applied rewrites97.9%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (sqrt (- (log (- 1.0 u1))))))
(if (<= (* t_0 (cos (* (* 2.0 (PI)) u2))) 0.14800000190734863)
(*
(sqrt (- (* (- (* (- (* -0.3333333333333333 u1) 0.5) u1) 1.0) u1)))
(cos (* (+ (PI) (PI)) u2)))
(* t_0 (+ (* (* (* (PI) (PI)) u2) (* -2.0 u2)) 1.0)))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{-\log \left(1 - u1\right)}\\
\mathbf{if}\;t\_0 \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \leq 0.14800000190734863:\\
\;\;\;\;\sqrt{-\left(\left(-0.3333333333333333 \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1} \cdot \cos \left(\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\mathbf{else}:\\
\;\;\;\;t\_0 \cdot \left(\left(\left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \cdot \left(-2 \cdot u2\right) + 1\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))) < 0.148Initial program 51.8%
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-*.f3298.9
Applied rewrites98.9%
lift-PI.f32N/A
add-cube-cbrtN/A
pow3N/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-cbrt.f3298.7
Applied rewrites98.7%
lift-*.f32N/A
lift-pow.f32N/A
lift-cbrt.f32N/A
rem-cube-cbrtN/A
lift-PI.f32N/A
lift-PI.f32N/A
count-2-revN/A
lower-+.f3298.9
Applied rewrites98.9%
Taylor expanded in u1 around 0
Applied rewrites98.2%
if 0.148 < (*.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 96.5%
Taylor expanded in u2 around 0
+-commutativeN/A
associate-*r*N/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3279.7
Applied rewrites79.7%
Applied rewrites91.3%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (sqrt (- (log (- 1.0 u1))))))
(if (<= (* t_0 (cos (* (* 2.0 (PI)) u2))) 0.07500000298023224)
(* (sqrt (- (* (- (* -0.5 u1) 1.0) u1))) (cos (* (+ (PI) (PI)) u2)))
(* t_0 (+ (* (* (* (PI) (PI)) u2) (* -2.0 u2)) 1.0)))))\begin{array}{l}
\\
\begin{array}{l}
t_0 := \sqrt{-\log \left(1 - u1\right)}\\
\mathbf{if}\;t\_0 \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \leq 0.07500000298023224:\\
\;\;\;\;\sqrt{-\left(-0.5 \cdot u1 - 1\right) \cdot u1} \cdot \cos \left(\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\mathbf{else}:\\
\;\;\;\;t\_0 \cdot \left(\left(\left(\mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right) \cdot \left(-2 \cdot u2\right) + 1\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))) < 0.075000003Initial program 47.1%
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-*.f3298.8
Applied rewrites98.8%
lift-PI.f32N/A
add-cube-cbrtN/A
pow3N/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-cbrt.f3298.7
Applied rewrites98.7%
lift-*.f32N/A
lift-pow.f32N/A
lift-cbrt.f32N/A
rem-cube-cbrtN/A
lift-PI.f32N/A
lift-PI.f32N/A
count-2-revN/A
lower-+.f3298.8
Applied rewrites98.8%
Taylor expanded in u1 around 0
Applied rewrites97.6%
if 0.075000003 < (*.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 94.6%
Taylor expanded in u2 around 0
+-commutativeN/A
associate-*r*N/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3262.1
Applied rewrites61.8%
Applied rewrites88.6%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(*
(sqrt
(-
(* (- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0) u1)))
(cos (* (+ (PI) (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(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
Initial program 59.1%
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-*.f3295.1
Applied rewrites95.1%
lift-PI.f32N/A
add-cube-cbrtN/A
pow3N/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-cbrt.f3295.0
Applied rewrites95.0%
lift-*.f32N/A
lift-pow.f32N/A
lift-cbrt.f32N/A
rem-cube-cbrtN/A
lift-PI.f32N/A
lift-PI.f32N/A
count-2-revN/A
lower-+.f3295.1
Applied rewrites95.1%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (* (- (* -0.5 u1) 1.0) u1))) (cos (* (+ (PI) (PI)) u2))))
\begin{array}{l}
\\
\sqrt{-\left(-0.5 \cdot u1 - 1\right) \cdot u1} \cdot \cos \left(\left(\mathsf{PI}\left(\right) + \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
Initial program 59.1%
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-*.f3295.1
Applied rewrites95.1%
lift-PI.f32N/A
add-cube-cbrtN/A
pow3N/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-cbrt.f3295.0
Applied rewrites95.0%
lift-*.f32N/A
lift-pow.f32N/A
lift-cbrt.f32N/A
rem-cube-cbrtN/A
lift-PI.f32N/A
lift-PI.f32N/A
count-2-revN/A
lower-+.f3295.1
Applied rewrites95.1%
Taylor expanded in u1 around 0
Applied rewrites88.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt u1) (cos (* (* 2.0 (PI)) u2))))
\begin{array}{l}
\\
\sqrt{u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)
\end{array}
Initial program 59.1%
lift-log.f32N/A
lift--.f32N/A
flip--N/A
log-divN/A
lower--.f32N/A
metadata-evalN/A
fp-cancel-sub-sign-invN/A
lower-log1p.f32N/A
lower-*.f32N/A
lower-neg.f32N/A
lower-log1p.f3241.5
Applied rewrites42.9%
Taylor expanded in u1 around 0
lower-sqrt.f3275.9
Applied rewrites75.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (- (log1p (- u1)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-log1pf(-u1));
}
function code(cosTheta_i, u1, u2) return sqrt(Float32(-log1p(Float32(-u1)))) end
\begin{array}{l}
\\
\sqrt{-\mathsf{log1p}\left(-u1\right)}
\end{array}
Initial program 59.1%
Taylor expanded in u2 around 0
lower-*.f32N/A
lower-sqrt.f32N/A
*-lft-identityN/A
metadata-evalN/A
fp-cancel-sign-sub-invN/A
mul-1-negN/A
lower-log1p.f32N/A
lower-neg.f32N/A
lower-sqrt.f32-0.0
Applied rewrites-0.0%
Applied rewrites64.7%
Final simplification64.9%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(*
(sqrt
(-
(* (- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0) u1)))
(fma (* (* -2.0 u2) u2) (* (PI) (PI)) 1.0)))\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 \mathsf{fma}\left(\left(-2 \cdot u2\right) \cdot u2, \mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right), 1\right)
\end{array}
Initial program 59.1%
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-*.f3295.1
Applied rewrites95.1%
lift-PI.f32N/A
add-cube-cbrtN/A
pow3N/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-cbrt.f3295.0
Applied rewrites95.0%
lift-*.f32N/A
lift-pow.f32N/A
lift-cbrt.f32N/A
rem-cube-cbrtN/A
lift-PI.f32N/A
lift-PI.f32N/A
count-2-revN/A
lower-+.f3295.1
Applied rewrites95.1%
Taylor expanded in u2 around 0
+-commutativeN/A
associate-*r*N/A
lower-fma.f32N/A
unpow2N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3277.1
Applied rewrites76.8%
Final simplification76.7%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(*
(sqrt
(-
(* (- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0) u1)))
(fma (* (* u2 u2) -2.0) (* (PI) (PI)) 1.0)))\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 \mathsf{fma}\left(\left(u2 \cdot u2\right) \cdot -2, \mathsf{PI}\left(\right) \cdot \mathsf{PI}\left(\right), 1\right)
\end{array}
Initial program 59.1%
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-*.f3295.1
Applied rewrites95.1%
Taylor expanded in u2 around 0
+-commutativeN/A
associate-*r*N/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-PI.f32N/A
lower-PI.f3277.1
Applied rewrites77.1%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt -1.0) (sqrt (- u1))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-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 = sqrt((-1.0e0)) * sqrt(-u1)
end function
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-1.0)) * sqrt(Float32(-u1))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(single(-1.0)) * sqrt(-u1); end
\begin{array}{l}
\\
\sqrt{-1} \cdot \sqrt{-u1}
\end{array}
Initial program 59.1%
Taylor expanded in u2 around 0
lower-*.f32N/A
lower-sqrt.f32N/A
*-lft-identityN/A
metadata-evalN/A
fp-cancel-sign-sub-invN/A
mul-1-negN/A
lower-log1p.f32N/A
lower-neg.f32N/A
lower-sqrt.f32-0.0
Applied rewrites-0.0%
Taylor expanded in u1 around 0
Applied rewrites-0.0%
Applied rewrites-0.0%
(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(Float32(-Float32(-u1))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-(-u1)); end
\begin{array}{l}
\\
\sqrt{-\left(-u1\right)}
\end{array}
Initial program 59.1%
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-*.f3295.1
Applied rewrites95.1%
lift-PI.f32N/A
add-cube-cbrtN/A
pow3N/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-cbrt.f3295.0
Applied rewrites95.0%
Taylor expanded in u1 around 0
mul-1-negN/A
lower-neg.f3275.9
Applied rewrites75.9%
lift-*.f32N/A
lift-*.f32N/A
lift-pow.f32N/A
lift-cbrt.f32N/A
rem-cube-cbrtN/A
lift-PI.f32N/A
lift-PI.f32N/A
associate-*l*N/A
*-commutativeN/A
lift-*.f32N/A
count-2-revN/A
flip-+N/A
Applied rewrites64.9%
Final simplification64.9%
herbie shell --seed 2024339
(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))))