
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-logf((1.0f - u1))) * cosf(((2.0f * ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log(Float32(Float32(1.0) - u1)))) * cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-log((single(1.0) - u1))) * cos(((single(2.0) * single(pi)) * u2)); end
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 12 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (sqrt (- (log (- 1.0 u1)))) (cos (* (* 2.0 PI) u2))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf(-logf((1.0f - u1))) * cosf(((2.0f * ((float) M_PI)) * u2));
}
function code(cosTheta_i, u1, u2) return Float32(sqrt(Float32(-log(Float32(Float32(1.0) - u1)))) * cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(-log((single(1.0) - u1))) * cos(((single(2.0) * single(pi)) * u2)); end
\begin{array}{l}
\\
\sqrt{-\log \left(1 - u1\right)} \cdot \cos \left(\left(2 \cdot \pi\right) \cdot u2\right)
\end{array}
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (cos (* (* 2.0 PI) u2)) (sqrt (- (log1p (- u1))))))
float code(float cosTheta_i, float u1, float u2) {
return cosf(((2.0f * ((float) M_PI)) * u2)) * sqrtf(-log1pf(-u1));
}
function code(cosTheta_i, u1, u2) return Float32(cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2)) * sqrt(Float32(-log1p(Float32(-u1))))) end
\begin{array}{l}
\\
\cos \left(\left(2 \cdot \pi\right) \cdot u2\right) \cdot \sqrt{-\mathsf{log1p}\left(-u1\right)}
\end{array}
Initial program 58.1%
sub-neg58.1%
log1p-define99.1%
Simplified99.1%
Final simplification99.1%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.00039999998989515007)
(sqrt (- (log1p (- u1))))
(*
(cos t_0)
(sqrt (* u1 (+ 1.0 (* u1 (- 0.5 (* u1 -0.3333333333333333))))))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.00039999998989515007f) {
tmp = sqrtf(-log1pf(-u1));
} else {
tmp = cosf(t_0) * sqrtf((u1 * (1.0f + (u1 * (0.5f - (u1 * -0.3333333333333333f))))));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(Float32(2.0) * Float32(pi)) * u2) tmp = Float32(0.0) if (t_0 <= Float32(0.00039999998989515007)) tmp = sqrt(Float32(-log1p(Float32(-u1)))); else tmp = Float32(cos(t_0) * sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) - Float32(u1 * Float32(-0.3333333333333333)))))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.00039999998989515007:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\cos t\_0 \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 - u1 \cdot -0.3333333333333333\right)\right)}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 3.9999999e-4Initial program 59.4%
sub-neg59.4%
log1p-define99.6%
Simplified99.6%
Taylor expanded in u2 around 0 99.5%
if 3.9999999e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 56.6%
Taylor expanded in u1 around 0 91.5%
Final simplification95.8%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (* (* 2.0 PI) u2) 0.00039999998989515007) (sqrt (- (log1p (- u1)))) (* u1 (* (cos (* u2 (* PI -2.0))) (sqrt (+ 0.5 (/ 1.0 u1)))))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (((2.0f * ((float) M_PI)) * u2) <= 0.00039999998989515007f) {
tmp = sqrtf(-log1pf(-u1));
} else {
tmp = u1 * (cosf((u2 * (((float) M_PI) * -2.0f))) * sqrtf((0.5f + (1.0f / u1))));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (Float32(Float32(Float32(2.0) * Float32(pi)) * u2) <= Float32(0.00039999998989515007)) tmp = sqrt(Float32(-log1p(Float32(-u1)))); else tmp = Float32(u1 * Float32(cos(Float32(u2 * Float32(Float32(pi) * Float32(-2.0)))) * sqrt(Float32(Float32(0.5) + Float32(Float32(1.0) / u1))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\left(2 \cdot \pi\right) \cdot u2 \leq 0.00039999998989515007:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\mathbf{else}:\\
\;\;\;\;u1 \cdot \left(\cos \left(u2 \cdot \left(\pi \cdot -2\right)\right) \cdot \sqrt{0.5 + \frac{1}{u1}}\right)\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 3.9999999e-4Initial program 59.4%
sub-neg59.4%
log1p-define99.6%
Simplified99.6%
Taylor expanded in u2 around 0 99.5%
if 3.9999999e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 56.6%
Taylor expanded in u1 around 0 88.4%
Taylor expanded in u1 around inf 88.5%
mul-1-neg88.5%
*-commutative88.5%
distribute-rgt-neg-in88.5%
Simplified88.5%
Taylor expanded in u2 around inf 88.1%
associate-*l*88.1%
associate-*r*88.1%
*-commutative88.1%
associate-*r*88.1%
*-commutative88.1%
associate-*r*88.1%
metadata-eval88.1%
distribute-rgt-neg-in88.1%
associate-*r*88.1%
rem-cube-cbrt88.1%
cos-neg88.1%
rem-cube-cbrt88.1%
+-commutative88.1%
Simplified88.1%
Final simplification94.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (if (<= (* (* 2.0 PI) u2) 0.00039999998989515007) (sqrt (- (log1p (- u1)))) (* (sqrt (* u1 (- 1.0 (* u1 -0.5)))) (cos (* 2.0 (* PI u2))))))
float code(float cosTheta_i, float u1, float u2) {
float tmp;
if (((2.0f * ((float) M_PI)) * u2) <= 0.00039999998989515007f) {
tmp = sqrtf(-log1pf(-u1));
} else {
tmp = sqrtf((u1 * (1.0f - (u1 * -0.5f)))) * cosf((2.0f * (((float) M_PI) * u2)));
}
return tmp;
}
function code(cosTheta_i, u1, u2) tmp = Float32(0.0) if (Float32(Float32(Float32(2.0) * Float32(pi)) * u2) <= Float32(0.00039999998989515007)) tmp = sqrt(Float32(-log1p(Float32(-u1)))); else tmp = Float32(sqrt(Float32(u1 * Float32(Float32(1.0) - Float32(u1 * Float32(-0.5))))) * cos(Float32(Float32(2.0) * Float32(Float32(pi) * u2)))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;\left(2 \cdot \pi\right) \cdot u2 \leq 0.00039999998989515007:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\sqrt{u1 \cdot \left(1 - u1 \cdot -0.5\right)} \cdot \cos \left(2 \cdot \left(\pi \cdot u2\right)\right)\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 3.9999999e-4Initial program 59.4%
sub-neg59.4%
log1p-define99.6%
Simplified99.6%
Taylor expanded in u2 around 0 99.5%
if 3.9999999e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 56.6%
Taylor expanded in u1 around 0 88.4%
pow1/288.4%
distribute-rgt-neg-in88.4%
unpow-prod-down88.0%
pow1/288.0%
*-commutative88.0%
fma-neg88.0%
metadata-eval88.0%
Applied egg-rr88.0%
unpow1/288.0%
Simplified88.0%
Taylor expanded in u2 around inf 88.4%
Final simplification94.5%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.00039999998989515007)
(sqrt (- (log1p (- u1))))
(* (cos t_0) (* (sqrt u1) (+ 1.0 (* u1 0.25)))))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.00039999998989515007f) {
tmp = sqrtf(-log1pf(-u1));
} else {
tmp = cosf(t_0) * (sqrtf(u1) * (1.0f + (u1 * 0.25f)));
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(Float32(2.0) * Float32(pi)) * u2) tmp = Float32(0.0) if (t_0 <= Float32(0.00039999998989515007)) tmp = sqrt(Float32(-log1p(Float32(-u1)))); else tmp = Float32(cos(t_0) * Float32(sqrt(u1) * Float32(Float32(1.0) + Float32(u1 * Float32(0.25))))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.00039999998989515007:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\cos t\_0 \cdot \left(\sqrt{u1} \cdot \left(1 + u1 \cdot 0.25\right)\right)\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 3.9999999e-4Initial program 59.4%
sub-neg59.4%
log1p-define99.6%
Simplified99.6%
Taylor expanded in u2 around 0 99.5%
if 3.9999999e-4 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 56.6%
Taylor expanded in u1 around 0 88.4%
pow1/288.4%
distribute-rgt-neg-in88.4%
unpow-prod-down88.0%
pow1/288.0%
*-commutative88.0%
fma-neg88.0%
metadata-eval88.0%
Applied egg-rr88.0%
unpow1/288.0%
Simplified88.0%
Taylor expanded in u1 around 0 88.6%
*-commutative88.6%
Simplified88.6%
Final simplification94.5%
(FPCore (cosTheta_i u1 u2) :precision binary32 (* (cos (* (* 2.0 PI) u2)) (sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 (- 0.3333333333333333 (* u1 -0.25))))))))))
float code(float cosTheta_i, float u1, float u2) {
return cosf(((2.0f * ((float) M_PI)) * u2)) * sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f - (u1 * -0.25f))))))));
}
function code(cosTheta_i, u1, u2) return Float32(cos(Float32(Float32(Float32(2.0) * Float32(pi)) * u2)) * sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) + Float32(u1 * Float32(Float32(0.3333333333333333) - Float32(u1 * Float32(-0.25)))))))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = cos(((single(2.0) * single(pi)) * u2)) * sqrt((u1 * (single(1.0) + (u1 * (single(0.5) + (u1 * (single(0.3333333333333333) - (u1 * single(-0.25))))))))); end
\begin{array}{l}
\\
\cos \left(\left(2 \cdot \pi\right) \cdot u2\right) \cdot \sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 + u1 \cdot \left(0.3333333333333333 - u1 \cdot -0.25\right)\right)\right)}
\end{array}
Initial program 58.1%
Taylor expanded in u1 around 0 94.1%
Final simplification94.1%
(FPCore (cosTheta_i u1 u2)
:precision binary32
(let* ((t_0 (* (* 2.0 PI) u2)))
(if (<= t_0 0.027000000700354576)
(sqrt (- (log1p (- u1))))
(* (cos t_0) (sqrt u1)))))
float code(float cosTheta_i, float u1, float u2) {
float t_0 = (2.0f * ((float) M_PI)) * u2;
float tmp;
if (t_0 <= 0.027000000700354576f) {
tmp = sqrtf(-log1pf(-u1));
} else {
tmp = cosf(t_0) * sqrtf(u1);
}
return tmp;
}
function code(cosTheta_i, u1, u2) t_0 = Float32(Float32(Float32(2.0) * Float32(pi)) * u2) tmp = Float32(0.0) if (t_0 <= Float32(0.027000000700354576)) tmp = sqrt(Float32(-log1p(Float32(-u1)))); else tmp = Float32(cos(t_0) * sqrt(u1)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(2 \cdot \pi\right) \cdot u2\\
\mathbf{if}\;t\_0 \leq 0.027000000700354576:\\
\;\;\;\;\sqrt{-\mathsf{log1p}\left(-u1\right)}\\
\mathbf{else}:\\
\;\;\;\;\cos t\_0 \cdot \sqrt{u1}\\
\end{array}
\end{array}
if (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) < 0.0270000007Initial program 59.2%
sub-neg59.2%
log1p-define99.5%
Simplified99.5%
Taylor expanded in u2 around 0 95.3%
if 0.0270000007 < (*.f32 (*.f32 #s(literal 2 binary32) (PI.f32)) u2) Initial program 55.4%
pow1/255.4%
pow-to-exp55.4%
add-sqr-sqrt55.4%
sqrt-unprod55.4%
sqr-neg55.4%
sqrt-unprod1.5%
add-sqr-sqrt1.5%
sub-neg1.5%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod76.2%
sqr-neg76.2%
sqrt-unprod76.2%
add-sqr-sqrt76.2%
Applied egg-rr76.2%
Taylor expanded in u1 around 0 79.1%
Final simplification90.7%
(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 58.1%
sub-neg58.1%
log1p-define99.1%
Simplified99.1%
Taylor expanded in u2 around 0 78.3%
Final simplification78.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* u1 (+ 1.0 (* u1 (+ 0.5 (* u1 (- 0.3333333333333333 (* u1 -0.25)))))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 * (1.0f + (u1 * (0.5f + (u1 * (0.3333333333333333f - (u1 * -0.25f))))))));
}
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 + (u1 * (0.5e0 + (u1 * (0.3333333333333333e0 - (u1 * (-0.25e0)))))))))
end function
function code(cosTheta_i, u1, u2) return sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) + Float32(u1 * Float32(Float32(0.3333333333333333) - Float32(u1 * Float32(-0.25))))))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 * (single(1.0) + (u1 * (single(0.5) + (u1 * (single(0.3333333333333333) - (u1 * single(-0.25))))))))); end
\begin{array}{l}
\\
\sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 + u1 \cdot \left(0.3333333333333333 - u1 \cdot -0.25\right)\right)\right)}
\end{array}
Initial program 58.1%
sub-neg58.1%
log1p-define99.1%
Simplified99.1%
Taylor expanded in u2 around 0 78.3%
Taylor expanded in u1 around 0 75.3%
Final simplification75.3%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* u1 (+ 1.0 (* u1 (- 0.5 (* u1 -0.3333333333333333)))))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 * (1.0f + (u1 * (0.5f - (u1 * -0.3333333333333333f))))));
}
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 + (u1 * (0.5e0 - (u1 * (-0.3333333333333333e0)))))))
end function
function code(cosTheta_i, u1, u2) return sqrt(Float32(u1 * Float32(Float32(1.0) + Float32(u1 * Float32(Float32(0.5) - Float32(u1 * Float32(-0.3333333333333333))))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 * (single(1.0) + (u1 * (single(0.5) - (u1 * single(-0.3333333333333333))))))); end
\begin{array}{l}
\\
\sqrt{u1 \cdot \left(1 + u1 \cdot \left(0.5 - u1 \cdot -0.3333333333333333\right)\right)}
\end{array}
Initial program 58.1%
sub-neg58.1%
log1p-define99.1%
Simplified99.1%
Taylor expanded in u2 around 0 78.3%
Taylor expanded in u1 around 0 74.2%
Final simplification74.2%
(FPCore (cosTheta_i u1 u2) :precision binary32 (sqrt (* u1 (- 1.0 (* u1 -0.5)))))
float code(float cosTheta_i, float u1, float u2) {
return sqrtf((u1 * (1.0f - (u1 * -0.5f))));
}
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 - (u1 * (-0.5e0)))))
end function
function code(cosTheta_i, u1, u2) return sqrt(Float32(u1 * Float32(Float32(1.0) - Float32(u1 * Float32(-0.5))))) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt((u1 * (single(1.0) - (u1 * single(-0.5))))); end
\begin{array}{l}
\\
\sqrt{u1 \cdot \left(1 - u1 \cdot -0.5\right)}
\end{array}
Initial program 58.1%
Taylor expanded in u1 around 0 89.1%
pow1/289.1%
distribute-rgt-neg-in89.1%
unpow-prod-down88.9%
pow1/288.9%
*-commutative88.9%
fma-neg88.9%
metadata-eval88.9%
Applied egg-rr88.9%
unpow1/288.9%
Simplified88.9%
Taylor expanded in u2 around 0 72.0%
Final simplification72.0%
(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(u1) end
function tmp = code(cosTheta_i, u1, u2) tmp = sqrt(u1); end
\begin{array}{l}
\\
\sqrt{u1}
\end{array}
Initial program 58.1%
pow1/258.1%
pow-to-exp58.2%
add-sqr-sqrt58.2%
sqrt-unprod58.2%
sqr-neg58.2%
sqrt-unprod1.3%
add-sqr-sqrt1.3%
sub-neg1.3%
log1p-undefine-0.0%
add-sqr-sqrt-0.0%
sqrt-unprod74.1%
sqr-neg74.1%
sqrt-unprod74.1%
add-sqr-sqrt74.1%
Applied egg-rr74.1%
Taylor expanded in u1 around 0 77.2%
Taylor expanded in u2 around 0 63.4%
Final simplification63.4%
herbie shell --seed 2024072
(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))))