
(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 (* (* 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 54.7%
*-commutative54.7%
sub-neg54.7%
log1p-def99.0%
Simplified99.0%
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(alpha * Float32(Float32(-alpha) * log1p(Float32(-u0)))) end
\begin{array}{l}
\\
\alpha \cdot \left(\left(-\alpha\right) \cdot \mathsf{log1p}\left(-u0\right)\right)
\end{array}
Initial program 54.7%
associate-*l*54.7%
sub-neg54.7%
log1p-def98.8%
Simplified98.8%
Final simplification98.8%
(FPCore (alpha u0) :precision binary32 (* (* alpha alpha) (+ u0 (+ (* (* u0 u0) (* u0 0.3333333333333333)) (* (* u0 u0) 0.5)))))
float code(float alpha, float u0) {
return (alpha * alpha) * (u0 + (((u0 * u0) * (u0 * 0.3333333333333333f)) + ((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) * (u0 * 0.3333333333333333e0)) + ((u0 * u0) * 0.5e0)))
end function
function code(alpha, u0) return Float32(Float32(alpha * alpha) * Float32(u0 + Float32(Float32(Float32(u0 * u0) * Float32(u0 * Float32(0.3333333333333333))) + Float32(Float32(u0 * u0) * Float32(0.5))))) end
function tmp = code(alpha, u0) tmp = (alpha * alpha) * (u0 + (((u0 * u0) * (u0 * single(0.3333333333333333))) + ((u0 * u0) * single(0.5)))); end
\begin{array}{l}
\\
\left(\alpha \cdot \alpha\right) \cdot \left(u0 + \left(\left(u0 \cdot u0\right) \cdot \left(u0 \cdot 0.3333333333333333\right) + \left(u0 \cdot u0\right) \cdot 0.5\right)\right)
\end{array}
Initial program 54.7%
associate-*l*54.7%
sub-neg54.7%
log1p-def98.8%
Simplified98.8%
Taylor expanded in u0 around 0 92.2%
*-commutative92.2%
+-commutative92.2%
associate-*r*92.2%
associate-*r*92.2%
distribute-rgt-out92.2%
distribute-lft-out92.3%
unpow292.2%
cube-mult92.2%
unpow292.2%
associate-*r*92.2%
distribute-rgt-out92.2%
unpow292.2%
Simplified92.2%
distribute-lft-in92.2%
*-commutative92.2%
Applied egg-rr92.2%
Final simplification92.2%
(FPCore (alpha u0) :precision binary32 (* (* alpha alpha) (+ u0 (* (* u0 u0) (+ 0.5 (* u0 0.3333333333333333))))))
float code(float alpha, float u0) {
return (alpha * alpha) * (u0 + ((u0 * u0) * (0.5f + (u0 * 0.3333333333333333f))));
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (alpha * alpha) * (u0 + ((u0 * u0) * (0.5e0 + (u0 * 0.3333333333333333e0))))
end function
function code(alpha, u0) return Float32(Float32(alpha * alpha) * Float32(u0 + Float32(Float32(u0 * u0) * Float32(Float32(0.5) + Float32(u0 * Float32(0.3333333333333333)))))) end
function tmp = code(alpha, u0) tmp = (alpha * alpha) * (u0 + ((u0 * u0) * (single(0.5) + (u0 * single(0.3333333333333333))))); end
\begin{array}{l}
\\
\left(\alpha \cdot \alpha\right) \cdot \left(u0 + \left(u0 \cdot u0\right) \cdot \left(0.5 + u0 \cdot 0.3333333333333333\right)\right)
\end{array}
Initial program 54.7%
associate-*l*54.7%
sub-neg54.7%
log1p-def98.8%
Simplified98.8%
Taylor expanded in u0 around 0 92.2%
*-commutative92.2%
+-commutative92.2%
associate-*r*92.2%
associate-*r*92.2%
distribute-rgt-out92.2%
distribute-lft-out92.3%
unpow292.2%
cube-mult92.2%
unpow292.2%
associate-*r*92.2%
distribute-rgt-out92.2%
unpow292.2%
Simplified92.2%
Final simplification92.2%
(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 54.7%
associate-*l*54.7%
sub-neg54.7%
log1p-def98.8%
Simplified98.8%
Taylor expanded in u0 around 0 87.3%
+-commutative87.3%
associate-*r*87.3%
distribute-rgt-out87.4%
unpow287.3%
unpow287.3%
Simplified87.3%
Final simplification87.3%
(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(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 54.7%
associate-*l*54.7%
sub-neg54.7%
log1p-def98.8%
Simplified98.8%
Taylor expanded in u0 around 0 74.9%
*-commutative74.9%
unpow274.9%
associate-*l*74.9%
Simplified74.9%
Final simplification74.9%
herbie shell --seed 2023187
(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))))