
(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) 0.999875009059906) (* (log (- 1.0 u0)) (/ -1.0 (pow alpha -2.0))) (* (/ -1.0 alpha) (* (* (* alpha alpha) (- u0)) alpha))))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.999875009059906f) {
tmp = logf((1.0f - u0)) * (-1.0f / powf(alpha, -2.0f));
} else {
tmp = (-1.0f / alpha) * (((alpha * alpha) * -u0) * alpha);
}
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) <= 0.999875009059906e0) then
tmp = log((1.0e0 - u0)) * ((-1.0e0) / (alpha ** (-2.0e0)))
else
tmp = ((-1.0e0) / alpha) * (((alpha * alpha) * -u0) * alpha)
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.999875009059906)) tmp = Float32(log(Float32(Float32(1.0) - u0)) * Float32(Float32(-1.0) / (alpha ^ Float32(-2.0)))); else tmp = Float32(Float32(Float32(-1.0) / alpha) * Float32(Float32(Float32(alpha * alpha) * Float32(-u0)) * alpha)); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if ((single(1.0) - u0) <= single(0.999875009059906)) tmp = log((single(1.0) - u0)) * (single(-1.0) / (alpha ^ single(-2.0))); else tmp = (single(-1.0) / alpha) * (((alpha * alpha) * -u0) * alpha); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.999875009059906:\\
\;\;\;\;\log \left(1 - u0\right) \cdot \frac{-1}{{\alpha}^{-2}}\\
\mathbf{else}:\\
\;\;\;\;\frac{-1}{\alpha} \cdot \left(\left(\left(\alpha \cdot \alpha\right) \cdot \left(-u0\right)\right) \cdot \alpha\right)\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.999875009Initial program 87.4%
+-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-*.f3287.4
Applied rewrites87.4%
lift-/.f32N/A
clear-numN/A
frac-2negN/A
metadata-evalN/A
lift--.f32N/A
sub0-negN/A
distribute-frac-neg2N/A
lift-*.f32N/A
pow2N/A
lift-*.f32N/A
lift-*.f32N/A
lift-*.f32N/A
swap-sqrN/A
lift-neg.f32N/A
lift-neg.f32N/A
sqr-negN/A
pow2N/A
pow2N/A
pow-sqrN/A
metadata-evalN/A
Applied rewrites87.5%
if 0.999875009 < (-.f32 #s(literal 1 binary32) u0) Initial program 35.1%
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
lower-/.f32N/A
lower-*.f3235.1
Applied rewrites35.1%
Taylor expanded in u0 around 0
mul-1-negN/A
lower-neg.f3291.2
Applied rewrites91.2%
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
lift-*.f32N/A
associate-*l*N/A
associate-/l*N/A
lower-*.f32N/A
lower-/.f32N/A
lower-*.f3291.2
Applied rewrites91.2%
lift-*.f32N/A
lift-/.f32N/A
associate-*r/N/A
div-invN/A
lower-*.f32N/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-/.f3291.3
Applied rewrites91.3%
Final simplification89.7%
(FPCore (alpha u0) :precision binary32 (if (<= (- 1.0 u0) 0.999875009059906) (* (/ 1.0 (/ -1.0 (* alpha alpha))) (log (- 1.0 u0))) (* (/ -1.0 alpha) (* (* (* alpha alpha) (- u0)) alpha))))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.999875009059906f) {
tmp = (1.0f / (-1.0f / (alpha * alpha))) * logf((1.0f - u0));
} else {
tmp = (-1.0f / alpha) * (((alpha * alpha) * -u0) * alpha);
}
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) <= 0.999875009059906e0) then
tmp = (1.0e0 / ((-1.0e0) / (alpha * alpha))) * log((1.0e0 - u0))
else
tmp = ((-1.0e0) / alpha) * (((alpha * alpha) * -u0) * alpha)
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.999875009059906)) tmp = Float32(Float32(Float32(1.0) / Float32(Float32(-1.0) / Float32(alpha * alpha))) * log(Float32(Float32(1.0) - u0))); else tmp = Float32(Float32(Float32(-1.0) / alpha) * Float32(Float32(Float32(alpha * alpha) * Float32(-u0)) * alpha)); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if ((single(1.0) - u0) <= single(0.999875009059906)) tmp = (single(1.0) / (single(-1.0) / (alpha * alpha))) * log((single(1.0) - u0)); else tmp = (single(-1.0) / alpha) * (((alpha * alpha) * -u0) * alpha); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.999875009059906:\\
\;\;\;\;\frac{1}{\frac{-1}{\alpha \cdot \alpha}} \cdot \log \left(1 - u0\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{-1}{\alpha} \cdot \left(\left(\left(\alpha \cdot \alpha\right) \cdot \left(-u0\right)\right) \cdot \alpha\right)\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.999875009Initial program 87.4%
lift-*.f32N/A
lift-neg.f32N/A
distribute-lft-neg-outN/A
neg-sub0N/A
flip3--N/A
clear-numN/A
lower-/.f32N/A
metadata-evalN/A
+-lft-identityN/A
mul0-lftN/A
metadata-evalN/A
sub-negN/A
--rgt-identityN/A
lower-/.f32N/A
pow2N/A
pow2N/A
pow-prod-upN/A
lower-pow.f32N/A
metadata-evalN/A
metadata-evalN/A
sub0-negN/A
Applied rewrites87.4%
Taylor expanded in alpha around 0
lower-/.f32N/A
unpow2N/A
lower-*.f3287.4
Applied rewrites87.4%
if 0.999875009 < (-.f32 #s(literal 1 binary32) u0) Initial program 35.1%
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
lower-/.f32N/A
lower-*.f3235.1
Applied rewrites35.1%
Taylor expanded in u0 around 0
mul-1-negN/A
lower-neg.f3291.2
Applied rewrites91.2%
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
lift-*.f32N/A
associate-*l*N/A
associate-/l*N/A
lower-*.f32N/A
lower-/.f32N/A
lower-*.f3291.2
Applied rewrites91.2%
lift-*.f32N/A
lift-/.f32N/A
associate-*r/N/A
div-invN/A
lower-*.f32N/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-/.f3291.3
Applied rewrites91.3%
Final simplification89.7%
(FPCore (alpha u0) :precision binary32 (if (<= (- 1.0 u0) 0.999875009059906) (* (* (- alpha) alpha) (log (- 1.0 u0))) (* (/ -1.0 alpha) (* (* (* alpha alpha) (- u0)) alpha))))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.999875009059906f) {
tmp = (-alpha * alpha) * logf((1.0f - u0));
} else {
tmp = (-1.0f / alpha) * (((alpha * alpha) * -u0) * alpha);
}
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) <= 0.999875009059906e0) then
tmp = (-alpha * alpha) * log((1.0e0 - u0))
else
tmp = ((-1.0e0) / alpha) * (((alpha * alpha) * -u0) * alpha)
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.999875009059906)) tmp = Float32(Float32(Float32(-alpha) * alpha) * log(Float32(Float32(1.0) - u0))); else tmp = Float32(Float32(Float32(-1.0) / alpha) * Float32(Float32(Float32(alpha * alpha) * Float32(-u0)) * alpha)); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if ((single(1.0) - u0) <= single(0.999875009059906)) tmp = (-alpha * alpha) * log((single(1.0) - u0)); else tmp = (single(-1.0) / alpha) * (((alpha * alpha) * -u0) * alpha); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.999875009059906:\\
\;\;\;\;\left(\left(-\alpha\right) \cdot \alpha\right) \cdot \log \left(1 - u0\right)\\
\mathbf{else}:\\
\;\;\;\;\frac{-1}{\alpha} \cdot \left(\left(\left(\alpha \cdot \alpha\right) \cdot \left(-u0\right)\right) \cdot \alpha\right)\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.999875009Initial program 87.4%
if 0.999875009 < (-.f32 #s(literal 1 binary32) u0) Initial program 35.1%
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
lower-/.f32N/A
lower-*.f3235.1
Applied rewrites35.1%
Taylor expanded in u0 around 0
mul-1-negN/A
lower-neg.f3291.2
Applied rewrites91.2%
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
lift-*.f32N/A
associate-*l*N/A
associate-/l*N/A
lower-*.f32N/A
lower-/.f32N/A
lower-*.f3291.2
Applied rewrites91.2%
lift-*.f32N/A
lift-/.f32N/A
associate-*r/N/A
div-invN/A
lower-*.f32N/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-/.f3291.3
Applied rewrites91.3%
Final simplification89.6%
(FPCore (alpha u0) :precision binary32 (* (/ -1.0 alpha) (* (* (* alpha alpha) (- u0)) alpha)))
float code(float alpha, float u0) {
return (-1.0f / alpha) * (((alpha * alpha) * -u0) * alpha);
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = ((-1.0e0) / alpha) * (((alpha * alpha) * -u0) * alpha)
end function
function code(alpha, u0) return Float32(Float32(Float32(-1.0) / alpha) * Float32(Float32(Float32(alpha * alpha) * Float32(-u0)) * alpha)) end
function tmp = code(alpha, u0) tmp = (single(-1.0) / alpha) * (((alpha * alpha) * -u0) * alpha); end
\begin{array}{l}
\\
\frac{-1}{\alpha} \cdot \left(\left(\left(\alpha \cdot \alpha\right) \cdot \left(-u0\right)\right) \cdot \alpha\right)
\end{array}
Initial program 57.4%
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
lower-/.f32N/A
lower-*.f3257.3
Applied rewrites57.3%
Taylor expanded in u0 around 0
mul-1-negN/A
lower-neg.f3272.9
Applied rewrites72.9%
lift-*.f32N/A
lift-/.f32N/A
associate-*l/N/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
lift-*.f32N/A
associate-*l*N/A
associate-/l*N/A
lower-*.f32N/A
lower-/.f32N/A
lower-*.f3272.9
Applied rewrites72.9%
lift-*.f32N/A
lift-/.f32N/A
associate-*r/N/A
div-invN/A
lower-*.f32N/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-/.f3273.0
Applied rewrites73.0%
Final simplification73.0%
(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 57.4%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f3273.0
Applied rewrites73.0%
Applied rewrites73.0%
Final simplification73.0%
(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 57.4%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f3273.0
Applied rewrites73.0%
Final simplification73.0%
herbie shell --seed 2024249
(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))))