
(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 6 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 (<= (- 1.0 u0) 0.9998199939727783)
(*
(log (- 1.0 u0))
(/ (* (* alpha alpha) (* (- alpha) alpha)) (* alpha alpha)))
(* (/ (* (* alpha alpha) alpha) alpha) u0)))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.9998199939727783f) {
tmp = logf((1.0f - u0)) * (((alpha * alpha) * (-alpha * alpha)) / (alpha * alpha));
} else {
tmp = (((alpha * alpha) * alpha) / alpha) * u0;
}
return tmp;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
real(4) :: tmp
if ((1.0e0 - u0) <= 0.9998199939727783e0) then
tmp = log((1.0e0 - u0)) * (((alpha * alpha) * (-alpha * alpha)) / (alpha * alpha))
else
tmp = (((alpha * alpha) * alpha) / alpha) * u0
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.9998199939727783)) tmp = Float32(log(Float32(Float32(1.0) - u0)) * Float32(Float32(Float32(alpha * alpha) * Float32(Float32(-alpha) * alpha)) / Float32(alpha * alpha))); else tmp = Float32(Float32(Float32(Float32(alpha * alpha) * alpha) / alpha) * u0); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if ((single(1.0) - u0) <= single(0.9998199939727783)) tmp = log((single(1.0) - u0)) * (((alpha * alpha) * (-alpha * alpha)) / (alpha * alpha)); else tmp = (((alpha * alpha) * alpha) / alpha) * u0; end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.9998199939727783:\\
\;\;\;\;\log \left(1 - u0\right) \cdot \frac{\left(\alpha \cdot \alpha\right) \cdot \left(\left(-\alpha\right) \cdot \alpha\right)}{\alpha \cdot \alpha}\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(\alpha \cdot \alpha\right) \cdot \alpha}{\alpha} \cdot u0\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.999819994Initial program 89.0%
+-lft-identityN/A
flip-+N/A
neg-sub0N/A
lift-*.f32N/A
lift-neg.f32N/A
distribute-lft-neg-outN/A
remove-double-negN/A
lower-/.f32N/A
metadata-evalN/A
lower--.f32N/A
lower-*.f32N/A
lower-*.f3289.1
Applied rewrites89.1%
lift--.f32N/A
sub0-negN/A
lift-*.f32N/A
distribute-rgt-neg-inN/A
lift-*.f32N/A
lift-neg.f32N/A
distribute-lft-neg-outN/A
lift-*.f32N/A
remove-double-negN/A
lower-*.f3289.1
Applied rewrites89.1%
if 0.999819994 < (-.f32 #s(literal 1 binary32) u0) Initial program 35.3%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f3291.2
Applied rewrites91.2%
Applied rewrites90.8%
Applied rewrites91.1%
Applied rewrites91.2%
Final simplification90.4%
(FPCore (alpha u0) :precision binary32 (if (<= (- 1.0 u0) 0.9998199939727783) (* (log (- 1.0 u0)) (* (- alpha) alpha)) (* (/ (* (* alpha alpha) alpha) alpha) u0)))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.9998199939727783f) {
tmp = logf((1.0f - u0)) * (-alpha * alpha);
} else {
tmp = (((alpha * alpha) * alpha) / alpha) * u0;
}
return tmp;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
real(4) :: tmp
if ((1.0e0 - u0) <= 0.9998199939727783e0) then
tmp = log((1.0e0 - u0)) * (-alpha * alpha)
else
tmp = (((alpha * alpha) * alpha) / alpha) * u0
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.9998199939727783)) tmp = Float32(log(Float32(Float32(1.0) - u0)) * Float32(Float32(-alpha) * alpha)); else tmp = Float32(Float32(Float32(Float32(alpha * alpha) * alpha) / alpha) * u0); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if ((single(1.0) - u0) <= single(0.9998199939727783)) tmp = log((single(1.0) - u0)) * (-alpha * alpha); else tmp = (((alpha * alpha) * alpha) / alpha) * u0; end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.9998199939727783:\\
\;\;\;\;\log \left(1 - u0\right) \cdot \left(\left(-\alpha\right) \cdot \alpha\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{\left(\alpha \cdot \alpha\right) \cdot \alpha}{\alpha} \cdot u0\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.999819994Initial program 89.0%
if 0.999819994 < (-.f32 #s(literal 1 binary32) u0) Initial program 35.3%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f3291.2
Applied rewrites91.2%
Applied rewrites90.8%
Applied rewrites91.1%
Applied rewrites91.2%
Final simplification90.4%
(FPCore (alpha u0) :precision binary32 (if (<= u0 0.00018000000272877514) (* (/ (* (* alpha alpha) alpha) alpha) u0) (* (* (log (- 1.0 u0)) (- alpha)) alpha)))
float code(float alpha, float u0) {
float tmp;
if (u0 <= 0.00018000000272877514f) {
tmp = (((alpha * alpha) * alpha) / alpha) * u0;
} else {
tmp = (logf((1.0f - u0)) * -alpha) * alpha;
}
return tmp;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
real(4) :: tmp
if (u0 <= 0.00018000000272877514e0) then
tmp = (((alpha * alpha) * alpha) / alpha) * u0
else
tmp = (log((1.0e0 - u0)) * -alpha) * alpha
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (u0 <= Float32(0.00018000000272877514)) tmp = Float32(Float32(Float32(Float32(alpha * alpha) * alpha) / alpha) * u0); else tmp = Float32(Float32(log(Float32(Float32(1.0) - u0)) * Float32(-alpha)) * alpha); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if (u0 <= single(0.00018000000272877514)) tmp = (((alpha * alpha) * alpha) / alpha) * u0; else tmp = (log((single(1.0) - u0)) * -alpha) * alpha; end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;u0 \leq 0.00018000000272877514:\\
\;\;\;\;\frac{\left(\alpha \cdot \alpha\right) \cdot \alpha}{\alpha} \cdot u0\\
\mathbf{else}:\\
\;\;\;\;\left(\log \left(1 - u0\right) \cdot \left(-\alpha\right)\right) \cdot \alpha\\
\end{array}
\end{array}
if u0 < 1.80000003e-4Initial program 35.3%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f3291.2
Applied rewrites91.2%
Applied rewrites90.8%
Applied rewrites91.1%
Applied rewrites91.2%
if 1.80000003e-4 < u0 Initial program 89.0%
Taylor expanded in alpha around 0
mul-1-negN/A
unpow2N/A
associate-*l*N/A
distribute-rgt-neg-inN/A
*-commutativeN/A
lower-*.f32N/A
distribute-lft-neg-inN/A
mul-1-negN/A
lower-*.f32N/A
mul-1-negN/A
lower-neg.f32N/A
sub-negN/A
lower-log1p.f32N/A
lower-neg.f3246.9
Applied rewrites46.9%
Applied rewrites88.8%
Final simplification90.3%
(FPCore (alpha u0) :precision binary32 (* (/ (* (* alpha alpha) alpha) alpha) u0))
float code(float alpha, float u0) {
return (((alpha * alpha) * alpha) / alpha) * u0;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (((alpha * alpha) * alpha) / alpha) * u0
end function
function code(alpha, u0) return Float32(Float32(Float32(Float32(alpha * alpha) * alpha) / alpha) * u0) end
function tmp = code(alpha, u0) tmp = (((alpha * alpha) * alpha) / alpha) * u0; end
\begin{array}{l}
\\
\frac{\left(\alpha \cdot \alpha\right) \cdot \alpha}{\alpha} \cdot u0
\end{array}
Initial program 56.1%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f3274.1
Applied rewrites74.1%
Applied rewrites73.8%
Applied rewrites74.0%
Applied rewrites74.1%
Final simplification74.1%
(FPCore (alpha u0) :precision binary32 (* (/ (* (* alpha alpha) u0) alpha) alpha))
float code(float alpha, float u0) {
return (((alpha * alpha) * u0) / alpha) * alpha;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (((alpha * alpha) * u0) / alpha) * alpha
end function
function code(alpha, u0) return Float32(Float32(Float32(Float32(alpha * alpha) * u0) / alpha) * alpha) end
function tmp = code(alpha, u0) tmp = (((alpha * alpha) * u0) / alpha) * alpha; end
\begin{array}{l}
\\
\frac{\left(\alpha \cdot \alpha\right) \cdot u0}{\alpha} \cdot \alpha
\end{array}
Initial program 56.1%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f3274.1
Applied rewrites74.1%
Applied rewrites74.0%
Applied rewrites73.9%
Applied rewrites74.1%
Final simplification74.1%
(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 56.1%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f3274.1
Applied rewrites74.1%
Final simplification74.1%
herbie shell --seed 2024259
(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))))