
(FPCore (alpha u0) :precision binary32 (* (* (- alpha) alpha) (log (- 1.0 u0))))
float code(float alpha, float u0) {
return (-alpha * alpha) * logf((1.0f - u0));
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (-alpha * alpha) * log((1.0e0 - u0))
end function
function code(alpha, u0) return Float32(Float32(Float32(-alpha) * alpha) * log(Float32(Float32(1.0) - u0))) end
function tmp = code(alpha, u0) tmp = (-alpha * alpha) * log((single(1.0) - u0)); end
\begin{array}{l}
\\
\left(\left(-\alpha\right) \cdot \alpha\right) \cdot \log \left(1 - u0\right)
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 7 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (alpha u0) :precision binary32 (* (* (- alpha) alpha) (log (- 1.0 u0))))
float code(float alpha, float u0) {
return (-alpha * alpha) * logf((1.0f - u0));
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (-alpha * alpha) * log((1.0e0 - u0))
end function
function code(alpha, u0) return Float32(Float32(Float32(-alpha) * alpha) * log(Float32(Float32(1.0) - u0))) end
function tmp = code(alpha, u0) tmp = (-alpha * alpha) * log((single(1.0) - u0)); end
\begin{array}{l}
\\
\left(\left(-\alpha\right) \cdot \alpha\right) \cdot \log \left(1 - u0\right)
\end{array}
(FPCore (alpha u0)
:precision binary32
(if (<= u0 0.0001900000061141327)
(* (* alpha u0) alpha)
(*
(log (- 1.0 u0))
(* (* (/ -1.0 (* alpha alpha)) (pow alpha 3.0)) alpha))))
float code(float alpha, float u0) {
float tmp;
if (u0 <= 0.0001900000061141327f) {
tmp = (alpha * u0) * alpha;
} else {
tmp = logf((1.0f - u0)) * (((-1.0f / (alpha * alpha)) * powf(alpha, 3.0f)) * alpha);
}
return tmp;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
real(4) :: tmp
if (u0 <= 0.0001900000061141327e0) then
tmp = (alpha * u0) * alpha
else
tmp = log((1.0e0 - u0)) * ((((-1.0e0) / (alpha * alpha)) * (alpha ** 3.0e0)) * alpha)
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (u0 <= Float32(0.0001900000061141327)) tmp = Float32(Float32(alpha * u0) * alpha); else tmp = Float32(log(Float32(Float32(1.0) - u0)) * Float32(Float32(Float32(Float32(-1.0) / Float32(alpha * alpha)) * (alpha ^ Float32(3.0))) * alpha)); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if (u0 <= single(0.0001900000061141327)) tmp = (alpha * u0) * alpha; else tmp = log((single(1.0) - u0)) * (((single(-1.0) / (alpha * alpha)) * (alpha ^ single(3.0))) * alpha); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u0 \leq 0.0001900000061141327:\\
\;\;\;\;\left(\alpha \cdot u0\right) \cdot \alpha\\
\mathbf{else}:\\
\;\;\;\;\log \left(1 - u0\right) \cdot \left(\left(\frac{-1}{\alpha \cdot \alpha} \cdot {\alpha}^{3}\right) \cdot \alpha\right)\\
\end{array}
\end{array}
if u0 < 1.90000006e-4Initial program 34.8%
Taylor expanded in u0 around 0
lower-*.f32N/A
unpow2N/A
lower-*.f3291.0
Applied rewrites91.0%
Applied rewrites91.0%
if 1.90000006e-4 < u0 Initial program 87.5%
lift-neg.f32N/A
neg-sub0N/A
flip3--N/A
frac-2negN/A
metadata-evalN/A
+-lft-identityN/A
mul0-lftN/A
+-rgt-identityN/A
distribute-lft-neg-outN/A
lift-neg.f32N/A
lift-*.f32N/A
div-invN/A
metadata-evalN/A
sub0-negN/A
remove-double-negN/A
lower-*.f32N/A
lower-pow.f32N/A
lower-/.f3287.6
Applied rewrites87.6%
lift-/.f32N/A
metadata-evalN/A
lift-*.f32N/A
lift-neg.f32N/A
distribute-lft-neg-outN/A
lift-*.f32N/A
frac-2negN/A
lower-/.f3287.6
Applied rewrites87.6%
Final simplification89.7%
(FPCore (alpha u0)
:precision binary32
(if (<= (- 1.0 u0) 0.999809980392456)
(* (log (- 1.0 u0)) (* (* (/ -1.0 (* alpha alpha)) (pow alpha 3.0)) alpha))
(*
(- (+ (log1p u0) (log1p (* u0 u0))) (log1p (- (pow u0 4.0))))
(* alpha alpha))))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.999809980392456f) {
tmp = logf((1.0f - u0)) * (((-1.0f / (alpha * alpha)) * powf(alpha, 3.0f)) * alpha);
} else {
tmp = ((log1pf(u0) + log1pf((u0 * u0))) - log1pf(-powf(u0, 4.0f))) * (alpha * alpha);
}
return tmp;
}
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.999809980392456)) tmp = Float32(log(Float32(Float32(1.0) - u0)) * Float32(Float32(Float32(Float32(-1.0) / Float32(alpha * alpha)) * (alpha ^ Float32(3.0))) * alpha)); else tmp = Float32(Float32(Float32(log1p(u0) + log1p(Float32(u0 * u0))) - log1p(Float32(-(u0 ^ Float32(4.0))))) * Float32(alpha * alpha)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.999809980392456:\\
\;\;\;\;\log \left(1 - u0\right) \cdot \left(\left(\frac{-1}{\alpha \cdot \alpha} \cdot {\alpha}^{3}\right) \cdot \alpha\right)\\
\mathbf{else}:\\
\;\;\;\;\left(\left(\mathsf{log1p}\left(u0\right) + \mathsf{log1p}\left(u0 \cdot u0\right)\right) - \mathsf{log1p}\left(-{u0}^{4}\right)\right) \cdot \left(\alpha \cdot \alpha\right)\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.99980998Initial program 87.5%
lift-neg.f32N/A
neg-sub0N/A
flip3--N/A
frac-2negN/A
metadata-evalN/A
+-lft-identityN/A
mul0-lftN/A
+-rgt-identityN/A
distribute-lft-neg-outN/A
lift-neg.f32N/A
lift-*.f32N/A
div-invN/A
metadata-evalN/A
sub0-negN/A
remove-double-negN/A
lower-*.f32N/A
lower-pow.f32N/A
lower-/.f3287.6
Applied rewrites87.6%
lift-/.f32N/A
metadata-evalN/A
lift-*.f32N/A
lift-neg.f32N/A
distribute-lft-neg-outN/A
lift-*.f32N/A
frac-2negN/A
lower-/.f3287.6
Applied rewrites87.6%
if 0.99980998 < (-.f32 #s(literal 1 binary32) u0) Initial program 34.8%
Applied rewrites91.1%
Final simplification47.4%
(FPCore (alpha u0) :precision binary32 (if (<= u0 0.0001900000061141327) (* (* alpha u0) alpha) (* (* (/ -1.0 alpha) (pow alpha 3.0)) (log (- 1.0 u0)))))
float code(float alpha, float u0) {
float tmp;
if (u0 <= 0.0001900000061141327f) {
tmp = (alpha * u0) * alpha;
} else {
tmp = ((-1.0f / alpha) * powf(alpha, 3.0f)) * logf((1.0f - u0));
}
return tmp;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
real(4) :: tmp
if (u0 <= 0.0001900000061141327e0) then
tmp = (alpha * u0) * alpha
else
tmp = (((-1.0e0) / alpha) * (alpha ** 3.0e0)) * log((1.0e0 - u0))
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (u0 <= Float32(0.0001900000061141327)) tmp = Float32(Float32(alpha * u0) * alpha); else tmp = Float32(Float32(Float32(Float32(-1.0) / alpha) * (alpha ^ Float32(3.0))) * log(Float32(Float32(1.0) - u0))); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if (u0 <= single(0.0001900000061141327)) tmp = (alpha * u0) * alpha; else tmp = ((single(-1.0) / alpha) * (alpha ^ single(3.0))) * log((single(1.0) - u0)); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u0 \leq 0.0001900000061141327:\\
\;\;\;\;\left(\alpha \cdot u0\right) \cdot \alpha\\
\mathbf{else}:\\
\;\;\;\;\left(\frac{-1}{\alpha} \cdot {\alpha}^{3}\right) \cdot \log \left(1 - u0\right)\\
\end{array}
\end{array}
if u0 < 1.90000006e-4Initial program 34.8%
Taylor expanded in u0 around 0
lower-*.f32N/A
unpow2N/A
lower-*.f3291.0
Applied rewrites91.0%
Applied rewrites91.0%
if 1.90000006e-4 < u0 Initial program 87.5%
lift-*.f32N/A
lift-neg.f32N/A
neg-sub0N/A
flip--N/A
metadata-evalN/A
neg-sub0N/A
distribute-lft-neg-outN/A
lift-neg.f32N/A
lift-*.f32N/A
+-lft-identityN/A
associate-*l/N/A
clear-numN/A
lower-/.f32N/A
lower-/.f32N/A
lower-*.f3287.4
Applied rewrites87.4%
lift-/.f32N/A
lift-/.f32N/A
frac-2negN/A
lift-neg.f32N/A
associate-/r/N/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
lift-neg.f32N/A
lift-*.f32N/A
distribute-lft-neg-outN/A
lift-*.f32N/A
cube-multN/A
metadata-evalN/A
remove-double-negN/A
*-commutativeN/A
lower-*.f32N/A
metadata-evalN/A
lower-pow.f32N/A
metadata-evalN/A
lift-neg.f32N/A
frac-2negN/A
lower-/.f3287.6
Applied rewrites87.6%
Final simplification89.6%
(FPCore (alpha u0) :precision binary32 (if (<= u0 0.0001900000061141327) (* (* alpha u0) alpha) (* (* (/ 1.0 (/ -1.0 alpha)) alpha) (log (- 1.0 u0)))))
float code(float alpha, float u0) {
float tmp;
if (u0 <= 0.0001900000061141327f) {
tmp = (alpha * u0) * alpha;
} else {
tmp = ((1.0f / (-1.0f / alpha)) * alpha) * logf((1.0f - u0));
}
return tmp;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
real(4) :: tmp
if (u0 <= 0.0001900000061141327e0) then
tmp = (alpha * u0) * alpha
else
tmp = ((1.0e0 / ((-1.0e0) / alpha)) * alpha) * log((1.0e0 - u0))
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (u0 <= Float32(0.0001900000061141327)) tmp = Float32(Float32(alpha * u0) * alpha); else tmp = Float32(Float32(Float32(Float32(1.0) / Float32(Float32(-1.0) / alpha)) * alpha) * log(Float32(Float32(1.0) - u0))); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if (u0 <= single(0.0001900000061141327)) tmp = (alpha * u0) * alpha; else tmp = ((single(1.0) / (single(-1.0) / alpha)) * alpha) * log((single(1.0) - u0)); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u0 \leq 0.0001900000061141327:\\
\;\;\;\;\left(\alpha \cdot u0\right) \cdot \alpha\\
\mathbf{else}:\\
\;\;\;\;\left(\frac{1}{\frac{-1}{\alpha}} \cdot \alpha\right) \cdot \log \left(1 - u0\right)\\
\end{array}
\end{array}
if u0 < 1.90000006e-4Initial program 34.8%
Taylor expanded in u0 around 0
lower-*.f32N/A
unpow2N/A
lower-*.f3291.0
Applied rewrites91.0%
Applied rewrites91.0%
if 1.90000006e-4 < u0 Initial program 87.5%
lift-neg.f32N/A
neg-sub0N/A
flip3--N/A
frac-2negN/A
metadata-evalN/A
+-lft-identityN/A
mul0-lftN/A
+-rgt-identityN/A
distribute-lft-neg-outN/A
lift-neg.f32N/A
lift-*.f32N/A
div-invN/A
metadata-evalN/A
sub0-negN/A
remove-double-negN/A
lower-*.f32N/A
lower-pow.f32N/A
lower-/.f3287.6
Applied rewrites87.6%
lift-*.f32N/A
lift-/.f32N/A
un-div-invN/A
lift-*.f32N/A
lift-neg.f32N/A
distribute-lft-neg-outN/A
lift-*.f32N/A
distribute-frac-neg2N/A
lift-pow.f32N/A
lift-*.f32N/A
pow2N/A
pow-divN/A
metadata-evalN/A
unpow1N/A
remove-double-divN/A
lift-/.f32N/A
distribute-frac-neg2N/A
neg-mul-1N/A
lift-/.f32N/A
div-invN/A
lift-/.f32N/A
lower-/.f3287.5
Applied rewrites87.5%
Final simplification89.6%
(FPCore (alpha u0) :precision binary32 (if (<= u0 0.0001900000061141327) (* (* alpha u0) alpha) (* (* (- alpha) alpha) (log (- 1.0 u0)))))
float code(float alpha, float u0) {
float tmp;
if (u0 <= 0.0001900000061141327f) {
tmp = (alpha * u0) * alpha;
} else {
tmp = (-alpha * alpha) * logf((1.0f - u0));
}
return tmp;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
real(4) :: tmp
if (u0 <= 0.0001900000061141327e0) then
tmp = (alpha * u0) * alpha
else
tmp = (-alpha * alpha) * log((1.0e0 - u0))
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (u0 <= Float32(0.0001900000061141327)) tmp = Float32(Float32(alpha * u0) * alpha); else tmp = Float32(Float32(Float32(-alpha) * alpha) * log(Float32(Float32(1.0) - u0))); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if (u0 <= single(0.0001900000061141327)) tmp = (alpha * u0) * alpha; else tmp = (-alpha * alpha) * log((single(1.0) - u0)); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u0 \leq 0.0001900000061141327:\\
\;\;\;\;\left(\alpha \cdot u0\right) \cdot \alpha\\
\mathbf{else}:\\
\;\;\;\;\left(\left(-\alpha\right) \cdot \alpha\right) \cdot \log \left(1 - u0\right)\\
\end{array}
\end{array}
if u0 < 1.90000006e-4Initial program 34.8%
Taylor expanded in u0 around 0
lower-*.f32N/A
unpow2N/A
lower-*.f3291.0
Applied rewrites91.0%
Applied rewrites91.0%
if 1.90000006e-4 < u0 Initial program 87.5%
Final simplification89.6%
(FPCore (alpha u0) :precision binary32 (* (* alpha u0) alpha))
float code(float alpha, float u0) {
return (alpha * u0) * alpha;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (alpha * u0) * alpha
end function
function code(alpha, u0) return Float32(Float32(alpha * u0) * alpha) end
function tmp = code(alpha, u0) tmp = (alpha * u0) * alpha; end
\begin{array}{l}
\\
\left(\alpha \cdot u0\right) \cdot \alpha
\end{array}
Initial program 56.2%
Taylor expanded in u0 around 0
lower-*.f32N/A
unpow2N/A
lower-*.f3273.9
Applied rewrites73.9%
Applied rewrites74.0%
Final simplification74.0%
(FPCore (alpha u0) :precision binary32 (* (* alpha alpha) u0))
float code(float alpha, float u0) {
return (alpha * alpha) * u0;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (alpha * alpha) * u0
end function
function code(alpha, u0) return Float32(Float32(alpha * alpha) * u0) end
function tmp = code(alpha, u0) tmp = (alpha * alpha) * u0; end
\begin{array}{l}
\\
\left(\alpha \cdot \alpha\right) \cdot u0
\end{array}
Initial program 56.2%
Taylor expanded in u0 around 0
lower-*.f32N/A
unpow2N/A
lower-*.f3273.9
Applied rewrites73.9%
herbie shell --seed 2024285
(FPCore (alpha u0)
:name "Beckmann Distribution sample, tan2theta, alphax == alphay"
:precision binary32
:pre (and (and (<= 0.0001 alpha) (<= alpha 1.0)) (and (<= 2.328306437e-10 u0) (<= u0 1.0)))
(* (* (- alpha) alpha) (log (- 1.0 u0))))