
(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 5 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) 0.9998499751091003)
(*
(* (pow alpha 2.5) (* (pow alpha 1.5) (- (pow alpha -2.0))))
(log (- 1.0 u0)))
(* (* u0 alpha) alpha)))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.9998499751091003f) {
tmp = (powf(alpha, 2.5f) * (powf(alpha, 1.5f) * -powf(alpha, -2.0f))) * logf((1.0f - u0));
} else {
tmp = (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 ((1.0e0 - u0) <= 0.9998499751091003e0) then
tmp = ((alpha ** 2.5e0) * ((alpha ** 1.5e0) * -(alpha ** (-2.0e0)))) * log((1.0e0 - u0))
else
tmp = (u0 * alpha) * alpha
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.9998499751091003)) tmp = Float32(Float32((alpha ^ Float32(2.5)) * Float32((alpha ^ Float32(1.5)) * Float32(-(alpha ^ Float32(-2.0))))) * log(Float32(Float32(1.0) - u0))); else tmp = Float32(Float32(u0 * alpha) * alpha); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if ((single(1.0) - u0) <= single(0.9998499751091003)) tmp = ((alpha ^ single(2.5)) * ((alpha ^ single(1.5)) * -(alpha ^ single(-2.0)))) * log((single(1.0) - u0)); else tmp = (u0 * alpha) * alpha; end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.9998499751091003:\\
\;\;\;\;\left({\alpha}^{2.5} \cdot \left({\alpha}^{1.5} \cdot \left(-{\alpha}^{-2}\right)\right)\right) \cdot \log \left(1 - u0\right)\\
\mathbf{else}:\\
\;\;\;\;\left(u0 \cdot \alpha\right) \cdot \alpha\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.999849975Initial program 87.6%
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-*.f3287.3
Applied rewrites87.3%
Applied rewrites87.6%
if 0.999849975 < (-.f32 #s(literal 1 binary32) u0) Initial program 33.4%
Taylor expanded in u0 around 0
lower-*.f32N/A
unpow2N/A
lower-*.f3291.8
Applied rewrites91.8%
Applied rewrites92.0%
(FPCore (alpha u0) :precision binary32 (if (<= (- 1.0 u0) 0.9998499751091003) (* (* (* (* alpha alpha) (/ -1.0 alpha)) alpha) (log (- 1.0 u0))) (* (* u0 alpha) alpha)))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.9998499751091003f) {
tmp = (((alpha * alpha) * (-1.0f / alpha)) * alpha) * logf((1.0f - u0));
} else {
tmp = (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 ((1.0e0 - u0) <= 0.9998499751091003e0) then
tmp = (((alpha * alpha) * ((-1.0e0) / alpha)) * alpha) * log((1.0e0 - u0))
else
tmp = (u0 * alpha) * alpha
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.9998499751091003)) tmp = Float32(Float32(Float32(Float32(alpha * alpha) * Float32(Float32(-1.0) / alpha)) * alpha) * log(Float32(Float32(1.0) - u0))); else tmp = Float32(Float32(u0 * alpha) * alpha); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if ((single(1.0) - u0) <= single(0.9998499751091003)) tmp = (((alpha * alpha) * (single(-1.0) / alpha)) * alpha) * log((single(1.0) - u0)); else tmp = (u0 * alpha) * alpha; end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.9998499751091003:\\
\;\;\;\;\left(\left(\left(\alpha \cdot \alpha\right) \cdot \frac{-1}{\alpha}\right) \cdot \alpha\right) \cdot \log \left(1 - u0\right)\\
\mathbf{else}:\\
\;\;\;\;\left(u0 \cdot \alpha\right) \cdot \alpha\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.999849975Initial program 87.6%
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
div-invN/A
lower-*.f32N/A
+-lft-identityN/A
lower-/.f3287.6
Applied rewrites87.6%
if 0.999849975 < (-.f32 #s(literal 1 binary32) u0) Initial program 33.4%
Taylor expanded in u0 around 0
lower-*.f32N/A
unpow2N/A
lower-*.f3291.8
Applied rewrites91.8%
Applied rewrites92.0%
Final simplification90.4%
(FPCore (alpha u0) :precision binary32 (if (<= (- 1.0 u0) 0.9998499751091003) (* (* (- alpha) alpha) (log (- 1.0 u0))) (* (* u0 alpha) alpha)))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.9998499751091003f) {
tmp = (-alpha * alpha) * logf((1.0f - u0));
} else {
tmp = (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 ((1.0e0 - u0) <= 0.9998499751091003e0) then
tmp = (-alpha * alpha) * log((1.0e0 - u0))
else
tmp = (u0 * alpha) * alpha
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.9998499751091003)) tmp = Float32(Float32(Float32(-alpha) * alpha) * log(Float32(Float32(1.0) - u0))); else tmp = Float32(Float32(u0 * alpha) * alpha); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if ((single(1.0) - u0) <= single(0.9998499751091003)) tmp = (-alpha * alpha) * log((single(1.0) - u0)); else tmp = (u0 * alpha) * alpha; end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.9998499751091003:\\
\;\;\;\;\left(\left(-\alpha\right) \cdot \alpha\right) \cdot \log \left(1 - u0\right)\\
\mathbf{else}:\\
\;\;\;\;\left(u0 \cdot \alpha\right) \cdot \alpha\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.999849975Initial program 87.6%
if 0.999849975 < (-.f32 #s(literal 1 binary32) u0) Initial program 33.4%
Taylor expanded in u0 around 0
lower-*.f32N/A
unpow2N/A
lower-*.f3291.8
Applied rewrites91.8%
Applied rewrites92.0%
(FPCore (alpha u0) :precision binary32 (* (* u0 alpha) alpha))
float code(float alpha, float u0) {
return (u0 * alpha) * alpha;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (u0 * alpha) * alpha
end function
function code(alpha, u0) return Float32(Float32(u0 * alpha) * alpha) end
function tmp = code(alpha, u0) tmp = (u0 * alpha) * alpha; end
\begin{array}{l}
\\
\left(u0 \cdot \alpha\right) \cdot \alpha
\end{array}
Initial program 53.3%
Taylor expanded in u0 around 0
lower-*.f32N/A
unpow2N/A
lower-*.f3276.4
Applied rewrites76.4%
Applied rewrites76.4%
(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 53.3%
Taylor expanded in u0 around 0
lower-*.f32N/A
unpow2N/A
lower-*.f3276.4
Applied rewrites76.4%
herbie shell --seed 2024325
(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))))