
(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 13 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 (fma (* alpha alpha) (log1p u0) (* (log1p (* u0 (- u0))) (* alpha (- alpha)))))
float code(float alpha, float u0) {
return fmaf((alpha * alpha), log1pf(u0), (log1pf((u0 * -u0)) * (alpha * -alpha)));
}
function code(alpha, u0) return fma(Float32(alpha * alpha), log1p(u0), Float32(log1p(Float32(u0 * Float32(-u0))) * Float32(alpha * Float32(-alpha)))) end
\begin{array}{l}
\\
\mathsf{fma}\left(\alpha \cdot \alpha, \mathsf{log1p}\left(u0\right), \mathsf{log1p}\left(u0 \cdot \left(-u0\right)\right) \cdot \left(\alpha \cdot \left(-\alpha\right)\right)\right)
\end{array}
Initial program 58.0%
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-*.f3257.9
lift-*.f32N/A
*-commutativeN/A
lower-*.f3257.9
Applied rewrites57.9%
Applied rewrites98.8%
lift--.f32N/A
sub-negN/A
+-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
*-lft-identityN/A
distribute-lft-neg-inN/A
lift-neg.f32N/A
remove-double-negN/A
lower-fma.f3299.0
lift-/.f32N/A
lift-*.f32N/A
lift-/.f32N/A
Applied rewrites99.0%
Final simplification99.0%
(FPCore (alpha u0) :precision binary32 (* (* alpha (- alpha)) (log1p (- u0))))
float code(float alpha, float u0) {
return (alpha * -alpha) * log1pf(-u0);
}
function code(alpha, u0) return Float32(Float32(alpha * Float32(-alpha)) * log1p(Float32(-u0))) end
\begin{array}{l}
\\
\left(\alpha \cdot \left(-\alpha\right)\right) \cdot \mathsf{log1p}\left(-u0\right)
\end{array}
Initial program 58.0%
lift-log.f32N/A
lift--.f32N/A
sub-negN/A
lower-log1p.f32N/A
lower-neg.f3298.9
Applied rewrites98.9%
Final simplification98.9%
(FPCore (alpha u0) :precision binary32 (* u0 (fma alpha alpha (* (* alpha alpha) (* u0 (fma u0 (fma u0 0.25 0.3333333333333333) 0.5))))))
float code(float alpha, float u0) {
return u0 * fmaf(alpha, alpha, ((alpha * alpha) * (u0 * fmaf(u0, fmaf(u0, 0.25f, 0.3333333333333333f), 0.5f))));
}
function code(alpha, u0) return Float32(u0 * fma(alpha, alpha, Float32(Float32(alpha * alpha) * Float32(u0 * fma(u0, fma(u0, Float32(0.25), Float32(0.3333333333333333)), Float32(0.5)))))) end
\begin{array}{l}
\\
u0 \cdot \mathsf{fma}\left(\alpha, \alpha, \left(\alpha \cdot \alpha\right) \cdot \left(u0 \cdot \mathsf{fma}\left(u0, \mathsf{fma}\left(u0, 0.25, 0.3333333333333333\right), 0.5\right)\right)\right)
\end{array}
Initial program 58.0%
Taylor expanded in u0 around 0
lower-*.f32N/A
lower-fma.f32N/A
Applied rewrites92.3%
Applied rewrites92.6%
(FPCore (alpha u0) :precision binary32 (* u0 (* alpha (fma (* alpha u0) (fma u0 (fma u0 0.25 0.3333333333333333) 0.5) alpha))))
float code(float alpha, float u0) {
return u0 * (alpha * fmaf((alpha * u0), fmaf(u0, fmaf(u0, 0.25f, 0.3333333333333333f), 0.5f), alpha));
}
function code(alpha, u0) return Float32(u0 * Float32(alpha * fma(Float32(alpha * u0), fma(u0, fma(u0, Float32(0.25), Float32(0.3333333333333333)), Float32(0.5)), alpha))) end
\begin{array}{l}
\\
u0 \cdot \left(\alpha \cdot \mathsf{fma}\left(\alpha \cdot u0, \mathsf{fma}\left(u0, \mathsf{fma}\left(u0, 0.25, 0.3333333333333333\right), 0.5\right), \alpha\right)\right)
\end{array}
Initial program 58.0%
Taylor expanded in u0 around 0
lower-*.f32N/A
lower-fma.f32N/A
Applied rewrites92.3%
Applied rewrites92.4%
Applied rewrites92.3%
Final simplification92.3%
(FPCore (alpha u0) :precision binary32 (* (* alpha alpha) (fma u0 (* u0 (fma u0 (fma u0 0.25 0.3333333333333333) 0.5)) u0)))
float code(float alpha, float u0) {
return (alpha * alpha) * fmaf(u0, (u0 * fmaf(u0, fmaf(u0, 0.25f, 0.3333333333333333f), 0.5f)), u0);
}
function code(alpha, u0) return Float32(Float32(alpha * alpha) * fma(u0, Float32(u0 * fma(u0, fma(u0, Float32(0.25), Float32(0.3333333333333333)), Float32(0.5))), u0)) end
\begin{array}{l}
\\
\left(\alpha \cdot \alpha\right) \cdot \mathsf{fma}\left(u0, u0 \cdot \mathsf{fma}\left(u0, \mathsf{fma}\left(u0, 0.25, 0.3333333333333333\right), 0.5\right), u0\right)
\end{array}
Initial program 58.0%
Taylor expanded in u0 around 0
lower-*.f32N/A
lower-fma.f32N/A
Applied rewrites92.3%
Applied rewrites92.0%
Taylor expanded in alpha around 0
Applied rewrites92.2%
(FPCore (alpha u0) :precision binary32 (* u0 (fma u0 (* alpha (* alpha (fma u0 0.3333333333333333 0.5))) (* alpha alpha))))
float code(float alpha, float u0) {
return u0 * fmaf(u0, (alpha * (alpha * fmaf(u0, 0.3333333333333333f, 0.5f))), (alpha * alpha));
}
function code(alpha, u0) return Float32(u0 * fma(u0, Float32(alpha * Float32(alpha * fma(u0, Float32(0.3333333333333333), Float32(0.5)))), Float32(alpha * alpha))) end
\begin{array}{l}
\\
u0 \cdot \mathsf{fma}\left(u0, \alpha \cdot \left(\alpha \cdot \mathsf{fma}\left(u0, 0.3333333333333333, 0.5\right)\right), \alpha \cdot \alpha\right)
\end{array}
Initial program 58.0%
Taylor expanded in u0 around 0
lower-*.f32N/A
lower-fma.f32N/A
*-commutativeN/A
associate-*r*N/A
distribute-rgt-outN/A
unpow2N/A
+-commutativeN/A
associate-*l*N/A
lower-*.f32N/A
lower-*.f32N/A
+-commutativeN/A
*-commutativeN/A
lower-fma.f32N/A
unpow2N/A
lower-*.f3290.3
Applied rewrites90.3%
(FPCore (alpha u0) :precision binary32 (* (* alpha (- alpha)) (- (* (fma u0 -0.3333333333333333 -0.5) (* u0 u0)) u0)))
float code(float alpha, float u0) {
return (alpha * -alpha) * ((fmaf(u0, -0.3333333333333333f, -0.5f) * (u0 * u0)) - u0);
}
function code(alpha, u0) return Float32(Float32(alpha * Float32(-alpha)) * Float32(Float32(fma(u0, Float32(-0.3333333333333333), Float32(-0.5)) * Float32(u0 * u0)) - u0)) end
\begin{array}{l}
\\
\left(\alpha \cdot \left(-\alpha\right)\right) \cdot \left(\mathsf{fma}\left(u0, -0.3333333333333333, -0.5\right) \cdot \left(u0 \cdot u0\right) - u0\right)
\end{array}
Initial program 58.0%
Taylor expanded in u0 around 0
lower-*.f32N/A
sub-negN/A
metadata-evalN/A
lower-fma.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f3290.1
Applied rewrites90.1%
Applied rewrites90.2%
Final simplification90.2%
(FPCore (alpha u0) :precision binary32 (* alpha (* (- alpha) (* u0 (fma u0 (fma u0 -0.3333333333333333 -0.5) -1.0)))))
float code(float alpha, float u0) {
return alpha * (-alpha * (u0 * fmaf(u0, fmaf(u0, -0.3333333333333333f, -0.5f), -1.0f)));
}
function code(alpha, u0) return Float32(alpha * Float32(Float32(-alpha) * Float32(u0 * fma(u0, fma(u0, Float32(-0.3333333333333333), Float32(-0.5)), Float32(-1.0))))) end
\begin{array}{l}
\\
\alpha \cdot \left(\left(-\alpha\right) \cdot \left(u0 \cdot \mathsf{fma}\left(u0, \mathsf{fma}\left(u0, -0.3333333333333333, -0.5\right), -1\right)\right)\right)
\end{array}
Initial program 58.0%
Taylor expanded in u0 around 0
lower-*.f32N/A
sub-negN/A
metadata-evalN/A
lower-fma.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f3290.1
Applied rewrites90.1%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f3290.1
Applied rewrites90.1%
Final simplification90.1%
(FPCore (alpha u0) :precision binary32 (* u0 (* (* alpha alpha) (fma u0 (fma u0 0.3333333333333333 0.5) 1.0))))
float code(float alpha, float u0) {
return u0 * ((alpha * alpha) * fmaf(u0, fmaf(u0, 0.3333333333333333f, 0.5f), 1.0f));
}
function code(alpha, u0) return Float32(u0 * Float32(Float32(alpha * alpha) * fma(u0, fma(u0, Float32(0.3333333333333333), Float32(0.5)), Float32(1.0)))) end
\begin{array}{l}
\\
u0 \cdot \left(\left(\alpha \cdot \alpha\right) \cdot \mathsf{fma}\left(u0, \mathsf{fma}\left(u0, 0.3333333333333333, 0.5\right), 1\right)\right)
\end{array}
Initial program 58.0%
Taylor expanded in u0 around 0
lower-*.f32N/A
lower-fma.f32N/A
Applied rewrites92.3%
Taylor expanded in u0 around 0
Applied rewrites92.1%
Taylor expanded in u0 around 0
Applied rewrites90.1%
(FPCore (alpha u0) :precision binary32 (* u0 (fma alpha alpha (* alpha (* 0.5 (* alpha u0))))))
float code(float alpha, float u0) {
return u0 * fmaf(alpha, alpha, (alpha * (0.5f * (alpha * u0))));
}
function code(alpha, u0) return Float32(u0 * fma(alpha, alpha, Float32(alpha * Float32(Float32(0.5) * Float32(alpha * u0))))) end
\begin{array}{l}
\\
u0 \cdot \mathsf{fma}\left(\alpha, \alpha, \alpha \cdot \left(0.5 \cdot \left(\alpha \cdot u0\right)\right)\right)
\end{array}
Initial program 58.0%
Taylor expanded in u0 around 0
lower-*.f32N/A
lower-fma.f32N/A
Applied rewrites92.3%
Taylor expanded in u0 around 0
Applied rewrites86.3%
Applied rewrites86.7%
(FPCore (alpha u0) :precision binary32 (* (* alpha alpha) (fma u0 (* u0 0.5) u0)))
float code(float alpha, float u0) {
return (alpha * alpha) * fmaf(u0, (u0 * 0.5f), u0);
}
function code(alpha, u0) return Float32(Float32(alpha * alpha) * fma(u0, Float32(u0 * Float32(0.5)), u0)) end
\begin{array}{l}
\\
\left(\alpha \cdot \alpha\right) \cdot \mathsf{fma}\left(u0, u0 \cdot 0.5, u0\right)
\end{array}
Initial program 58.0%
Taylor expanded in u0 around 0
distribute-lft-inN/A
associate-*r*N/A
*-commutativeN/A
associate-*r*N/A
distribute-rgt-outN/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
associate-*r*N/A
lower-fma.f32N/A
*-commutativeN/A
lower-*.f3286.4
Applied rewrites86.4%
(FPCore (alpha u0) :precision binary32 (* u0 (* (* alpha alpha) (fma u0 0.5 1.0))))
float code(float alpha, float u0) {
return u0 * ((alpha * alpha) * fmaf(u0, 0.5f, 1.0f));
}
function code(alpha, u0) return Float32(u0 * Float32(Float32(alpha * alpha) * fma(u0, Float32(0.5), Float32(1.0)))) end
\begin{array}{l}
\\
u0 \cdot \left(\left(\alpha \cdot \alpha\right) \cdot \mathsf{fma}\left(u0, 0.5, 1\right)\right)
\end{array}
Initial program 58.0%
Taylor expanded in u0 around 0
lower-*.f32N/A
lower-fma.f32N/A
Applied rewrites92.3%
Taylor expanded in u0 around 0
Applied rewrites86.3%
(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 58.0%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
unpow2N/A
lower-*.f3273.2
Applied rewrites73.2%
Final simplification73.2%
herbie shell --seed 2024234
(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))))