
(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 (* (* 2.0 (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(2 \cdot \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%
if 0.0399999991 < u1 Initial program 97.9%
(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 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%
(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 59.1%
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-*.f3292.9
Applied rewrites92.9%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= u2 9.500000305706635e-5)
(*
(sqrt
(-
(*
(- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0)
u1)))
1.0)
(* (sqrt (* (- 1.0 (* -0.5 u1)) u1)) (cos (* (* 2.0 (PI)) u2)))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \leq 9.500000305706635 \cdot 10^{-5}:\\
\;\;\;\;\sqrt{-\left(\left(\left(-0.25 \cdot u1 - 0.3333333333333333\right) \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1} \cdot 1\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\left(1 - -0.5 \cdot u1\right) \cdot u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\end{array}
\end{array}
if u2 < 9.50000031e-5Initial program 57.5%
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-*.f3295.9
Applied rewrites95.9%
Taylor expanded in u2 around 0
Applied rewrites95.7%
if 9.50000031e-5 < u2 Initial program 61.2%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
+-commutativeN/A
lower-fma.f3234.2
Applied rewrites32.4%
Taylor expanded in u1 around inf
Applied rewrites87.4%
Applied rewrites87.4%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(if (<= u2 0.00046999999904073775)
(*
(sqrt
(-
(*
(- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0)
u1)))
1.0)
(* (sqrt u1) (cos (* (* 2.0 (PI)) u2)))))\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u2 \leq 0.00046999999904073775:\\
\;\;\;\;\sqrt{-\left(\left(\left(-0.25 \cdot u1 - 0.3333333333333333\right) \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1} \cdot 1\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1} \cdot \cos \left(\left(2 \cdot \mathsf{PI}\left(\right)\right) \cdot u2\right)\\
\end{array}
\end{array}
if u2 < 4.69999999e-4Initial program 58.8%
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-*.f3295.8
Applied rewrites95.8%
Taylor expanded in u2 around 0
Applied rewrites94.5%
if 4.69999999e-4 < u2 Initial program 59.8%
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.f329.0
Applied rewrites7.9%
Taylor expanded in u1 around 0
lower-sqrt.f3275.0
Applied rewrites75.0%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(*
(sqrt
(-
(* (- (* (- (* (- (* -0.25 u1) 0.3333333333333333) u1) 0.5) u1) 1.0) u1)))
1.0))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-(((((((-0.25f * u1) - 0.3333333333333333f) * u1) - 0.5f) * u1) - 1.0f) * 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 = sqrt(-((((((((-0.25e0) * u1) - 0.3333333333333333e0) * u1) - 0.5e0) * u1) - 1.0e0) * u1)) * 1.0e0
end function
function code(cosTheta_i, u1, u2) return Float32(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))) * Float32(1.0)) 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)) * single(1.0); 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} \cdot 1
\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
Applied rewrites77.1%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (* (- (* (- (* -0.3333333333333333 u1) 0.5) u1) 1.0) u1))) 1.0))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-(((((-0.3333333333333333f * u1) - 0.5f) * u1) - 1.0f) * 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 = sqrt(-((((((-0.3333333333333333e0) * u1) - 0.5e0) * u1) - 1.0e0) * u1)) * 1.0e0
end function
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-Float32(Float32(Float32(Float32(Float32(Float32(-0.3333333333333333) * u1) - Float32(0.5)) * u1) - Float32(1.0)) * u1))) * Float32(1.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-(((((single(-0.3333333333333333) * u1) - single(0.5)) * u1) - single(1.0)) * u1)) * single(1.0); end
\begin{array}{l}
\\
\sqrt{-\left(\left(-0.3333333333333333 \cdot u1 - 0.5\right) \cdot u1 - 1\right) \cdot u1} \cdot 1
\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
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-*.f3292.9
Applied rewrites92.9%
Taylor expanded in u2 around 0
Applied rewrites76.0%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (+ (* (* 0.5 u1) u1) u1)) 1.0))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((((0.5f * u1) * u1) + 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 = sqrt((((0.5e0 * u1) * u1) + u1)) * 1.0e0
end function
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(Float32(Float32(Float32(0.5) * u1) * u1) + u1)) * Float32(1.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((((single(0.5) * u1) * u1) + u1)) * single(1.0); end
\begin{array}{l}
\\
\sqrt{\left(0.5 \cdot u1\right) \cdot u1 + u1} \cdot 1
\end{array}
Initial program 59.1%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
+-commutativeN/A
lower-fma.f3255.4
Applied rewrites55.9%
Taylor expanded in u2 around 0
Applied rewrites64.7%
Applied rewrites72.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (* (fma 0.5 u1 1.0) u1)) 1.0))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((fmaf(0.5f, u1, 1.0f) * u1)) * 1.0f;
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(fma(Float32(0.5), u1, Float32(1.0)) * u1)) * Float32(1.0)) end
\begin{array}{l}
\\
\sqrt{\mathsf{fma}\left(0.5, u1, 1\right) \cdot u1} \cdot 1
\end{array}
Initial program 59.1%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
+-commutativeN/A
lower-fma.f3256.6
Applied rewrites55.9%
Taylor expanded in u2 around 0
Applied rewrites64.9%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (* (* u1 u1) 0.5)) 1.0))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(((u1 * u1) * 0.5f)) * 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 = sqrt(((u1 * u1) * 0.5e0)) * 1.0e0
end function
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(Float32(u1 * u1) * Float32(0.5))) * Float32(1.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(((u1 * u1) * single(0.5))) * single(1.0); end
\begin{array}{l}
\\
\sqrt{\left(u1 \cdot u1\right) \cdot 0.5} \cdot 1
\end{array}
Initial program 59.1%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
+-commutativeN/A
lower-fma.f3256.6
Applied rewrites55.7%
Taylor expanded in u2 around 0
Applied rewrites64.9%
Taylor expanded in u1 around inf
Applied rewrites19.1%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (- (sqrt u1)) 1.0))
float code(float cosTheta_i, float u1, float u2) {
return -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 = -sqrt(u1) * 1.0e0
end function
function code(cosTheta_i, u1, u2) return Float32(Float32(-sqrt(u1)) * Float32(1.0)) end
function tmp = code(cosTheta_i, u1, u2) tmp = -sqrt(u1) * single(1.0); end
\begin{array}{l}
\\
\left(-\sqrt{u1}\right) \cdot 1
\end{array}
Initial program 59.1%
Taylor expanded in u1 around 0
*-commutativeN/A
lower-*.f32N/A
+-commutativeN/A
lower-fma.f3256.6
Applied rewrites55.8%
Taylor expanded in u2 around 0
Applied rewrites64.7%
Taylor expanded in u1 around 0
*-commutativeN/A
unpow2N/A
rem-square-sqrtN/A
lower-*.f32N/A
lower-sqrt.f324.3
Applied rewrites4.3%
Taylor expanded in u1 around 0
*-commutativeN/A
unpow2N/A
rem-square-sqrtN/A
mul-1-negN/A
lower-neg.f32N/A
lower-sqrt.f324.3
Applied rewrites4.3%
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))))