
(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 (* (* 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 53.9%
*-commutative53.9%
sub-neg53.9%
log1p-def98.9%
Simplified98.9%
Final simplification98.9%
(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(alpha * Float32(alpha * Float32(-log1p(Float32(-u0))))) end
\begin{array}{l}
\\
\alpha \cdot \left(\alpha \cdot \left(-\mathsf{log1p}\left(-u0\right)\right)\right)
\end{array}
Initial program 53.9%
associate-*l*53.9%
sub-neg53.9%
log1p-def98.9%
Simplified98.9%
Final simplification98.9%
(FPCore (alpha u0) :precision binary32 (+ (* (* (* u0 u0) (+ (* u0 0.3333333333333333) 0.5)) (* alpha alpha)) (* u0 (* alpha alpha))))
float code(float alpha, float u0) {
return (((u0 * u0) * ((u0 * 0.3333333333333333f) + 0.5f)) * (alpha * alpha)) + (u0 * (alpha * alpha));
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (((u0 * u0) * ((u0 * 0.3333333333333333e0) + 0.5e0)) * (alpha * alpha)) + (u0 * (alpha * alpha))
end function
function code(alpha, u0) return Float32(Float32(Float32(Float32(u0 * u0) * Float32(Float32(u0 * Float32(0.3333333333333333)) + Float32(0.5))) * Float32(alpha * alpha)) + Float32(u0 * Float32(alpha * alpha))) end
function tmp = code(alpha, u0) tmp = (((u0 * u0) * ((u0 * single(0.3333333333333333)) + single(0.5))) * (alpha * alpha)) + (u0 * (alpha * alpha)); end
\begin{array}{l}
\\
\left(\left(u0 \cdot u0\right) \cdot \left(u0 \cdot 0.3333333333333333 + 0.5\right)\right) \cdot \left(\alpha \cdot \alpha\right) + u0 \cdot \left(\alpha \cdot \alpha\right)
\end{array}
Initial program 53.9%
associate-*l*53.9%
Simplified53.9%
Taylor expanded in u0 around 0 94.2%
associate-+r+94.2%
+-commutative94.2%
+-commutative94.2%
associate-*r*94.2%
associate-*r*94.2%
distribute-rgt-out94.2%
associate-*r*94.2%
distribute-rgt-out94.2%
distribute-lft-out94.1%
unpow294.1%
Simplified94.1%
distribute-rgt-in94.2%
+-commutative94.2%
fma-def94.2%
Applied egg-rr94.2%
Taylor expanded in u0 around 0 92.1%
unpow292.1%
Simplified92.1%
Final simplification92.1%
(FPCore (alpha u0) :precision binary32 (* (* alpha alpha) (+ u0 (* (* u0 u0) (+ (* u0 0.3333333333333333) 0.5)))))
float code(float alpha, float u0) {
return (alpha * alpha) * (u0 + ((u0 * u0) * ((u0 * 0.3333333333333333f) + 0.5f)));
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (alpha * alpha) * (u0 + ((u0 * u0) * ((u0 * 0.3333333333333333e0) + 0.5e0)))
end function
function code(alpha, u0) return Float32(Float32(alpha * alpha) * Float32(u0 + Float32(Float32(u0 * u0) * Float32(Float32(u0 * Float32(0.3333333333333333)) + Float32(0.5))))) end
function tmp = code(alpha, u0) tmp = (alpha * alpha) * (u0 + ((u0 * u0) * ((u0 * single(0.3333333333333333)) + single(0.5)))); end
\begin{array}{l}
\\
\left(\alpha \cdot \alpha\right) \cdot \left(u0 + \left(u0 \cdot u0\right) \cdot \left(u0 \cdot 0.3333333333333333 + 0.5\right)\right)
\end{array}
Initial program 53.9%
associate-*l*53.9%
Simplified53.9%
Taylor expanded in u0 around 0 92.1%
*-commutative92.1%
+-commutative92.1%
associate-*r*92.1%
associate-*r*92.1%
distribute-rgt-out92.1%
distribute-lft-out92.0%
unpow292.0%
cube-mult92.0%
unpow292.0%
associate-*r*92.0%
distribute-rgt-out92.0%
unpow292.0%
Simplified92.0%
Final simplification92.0%
(FPCore (alpha u0) :precision binary32 (* (* alpha alpha) (+ u0 (* (* u0 u0) 0.5))))
float code(float alpha, float u0) {
return (alpha * alpha) * (u0 + ((u0 * u0) * 0.5f));
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (alpha * alpha) * (u0 + ((u0 * u0) * 0.5e0))
end function
function code(alpha, u0) return Float32(Float32(alpha * alpha) * Float32(u0 + Float32(Float32(u0 * u0) * Float32(0.5)))) end
function tmp = code(alpha, u0) tmp = (alpha * alpha) * (u0 + ((u0 * u0) * single(0.5))); end
\begin{array}{l}
\\
\left(\alpha \cdot \alpha\right) \cdot \left(u0 + \left(u0 \cdot u0\right) \cdot 0.5\right)
\end{array}
Initial program 53.9%
associate-*l*53.9%
Simplified53.9%
Taylor expanded in u0 around 0 88.2%
associate-*r*88.2%
distribute-rgt-out88.2%
unpow288.2%
*-commutative88.2%
unpow288.2%
Simplified88.2%
Final simplification88.2%
(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(u0 * Float32(alpha * alpha)) end
function tmp = code(alpha, u0) tmp = u0 * (alpha * alpha); end
\begin{array}{l}
\\
u0 \cdot \left(\alpha \cdot \alpha\right)
\end{array}
Initial program 53.9%
associate-*l*53.9%
Simplified53.9%
Taylor expanded in u0 around 0 75.8%
unpow275.8%
Simplified75.8%
Final simplification75.8%
(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(alpha * Float32(alpha * u0)) end
function tmp = code(alpha, u0) tmp = alpha * (alpha * u0); end
\begin{array}{l}
\\
\alpha \cdot \left(\alpha \cdot u0\right)
\end{array}
Initial program 53.9%
associate-*l*53.9%
Simplified53.9%
Taylor expanded in u0 around 0 75.8%
unpow275.8%
Simplified75.8%
add-cube-cbrt75.2%
pow375.3%
Applied egg-rr75.3%
rem-cube-cbrt75.8%
associate-*r*75.8%
Applied egg-rr75.8%
Final simplification75.8%
herbie shell --seed 2023200
(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))))