
(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 8 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%
distribute-lft-neg-out54.7%
sub-neg54.7%
log1p-define99.0%
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(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 54.7%
associate-*l*54.6%
distribute-lft-neg-out54.6%
distribute-rgt-neg-in54.6%
distribute-lft-neg-out54.6%
sub-neg54.6%
log1p-define98.9%
Simplified98.9%
Final simplification98.9%
(FPCore (alpha u0)
:precision binary32
(*
alpha
(*
u0
(+
alpha
(* alpha (* u0 (+ 0.5 (* u0 (+ 0.3333333333333333 (* u0 0.25))))))))))
float code(float alpha, float u0) {
return alpha * (u0 * (alpha + (alpha * (u0 * (0.5f + (u0 * (0.3333333333333333f + (u0 * 0.25f))))))));
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = alpha * (u0 * (alpha + (alpha * (u0 * (0.5e0 + (u0 * (0.3333333333333333e0 + (u0 * 0.25e0))))))))
end function
function code(alpha, u0) return Float32(alpha * Float32(u0 * Float32(alpha + Float32(alpha * Float32(u0 * Float32(Float32(0.5) + Float32(u0 * Float32(Float32(0.3333333333333333) + Float32(u0 * Float32(0.25)))))))))) end
function tmp = code(alpha, u0) tmp = alpha * (u0 * (alpha + (alpha * (u0 * (single(0.5) + (u0 * (single(0.3333333333333333) + (u0 * single(0.25))))))))); end
\begin{array}{l}
\\
\alpha \cdot \left(u0 \cdot \left(\alpha + \alpha \cdot \left(u0 \cdot \left(0.5 + u0 \cdot \left(0.3333333333333333 + u0 \cdot 0.25\right)\right)\right)\right)\right)
\end{array}
Initial program 54.7%
associate-*l*54.6%
distribute-lft-neg-out54.6%
distribute-rgt-neg-in54.6%
distribute-lft-neg-out54.6%
sub-neg54.6%
log1p-define98.9%
Simplified98.9%
Taylor expanded in u0 around 0 91.9%
Taylor expanded in alpha around 0 91.9%
*-commutative91.9%
Simplified91.9%
(FPCore (alpha u0) :precision binary32 (* alpha (* u0 (+ alpha (* alpha (* u0 (+ 0.5 (* u0 0.3333333333333333))))))))
float code(float alpha, float u0) {
return alpha * (u0 * (alpha + (alpha * (u0 * (0.5f + (u0 * 0.3333333333333333f))))));
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = alpha * (u0 * (alpha + (alpha * (u0 * (0.5e0 + (u0 * 0.3333333333333333e0))))))
end function
function code(alpha, u0) return Float32(alpha * Float32(u0 * Float32(alpha + Float32(alpha * Float32(u0 * Float32(Float32(0.5) + Float32(u0 * Float32(0.3333333333333333)))))))) end
function tmp = code(alpha, u0) tmp = alpha * (u0 * (alpha + (alpha * (u0 * (single(0.5) + (u0 * single(0.3333333333333333))))))); end
\begin{array}{l}
\\
\alpha \cdot \left(u0 \cdot \left(\alpha + \alpha \cdot \left(u0 \cdot \left(0.5 + u0 \cdot 0.3333333333333333\right)\right)\right)\right)
\end{array}
Initial program 54.7%
associate-*l*54.6%
distribute-lft-neg-out54.6%
distribute-rgt-neg-in54.6%
distribute-lft-neg-out54.6%
sub-neg54.6%
log1p-define98.9%
Simplified98.9%
Taylor expanded in u0 around 0 91.9%
Taylor expanded in u0 around 0 89.8%
*-commutative89.8%
associate-*l*89.8%
Simplified89.8%
Taylor expanded in u0 around 0 89.8%
+-commutative89.8%
associate-*r*89.8%
*-commutative89.8%
associate-*r*89.8%
distribute-rgt-in89.8%
associate-*r*89.8%
*-commutative89.8%
+-commutative89.8%
*-commutative89.8%
+-commutative89.8%
associate-*r*89.8%
*-commutative89.8%
Simplified89.8%
(FPCore (alpha u0) :precision binary32 (* alpha (* u0 (+ alpha (* 0.5 (* alpha u0))))))
float code(float alpha, float u0) {
return alpha * (u0 * (alpha + (0.5f * (alpha * u0))));
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = alpha * (u0 * (alpha + (0.5e0 * (alpha * u0))))
end function
function code(alpha, u0) return Float32(alpha * Float32(u0 * Float32(alpha + Float32(Float32(0.5) * Float32(alpha * u0))))) end
function tmp = code(alpha, u0) tmp = alpha * (u0 * (alpha + (single(0.5) * (alpha * u0)))); end
\begin{array}{l}
\\
\alpha \cdot \left(u0 \cdot \left(\alpha + 0.5 \cdot \left(\alpha \cdot u0\right)\right)\right)
\end{array}
Initial program 54.7%
associate-*l*54.6%
distribute-lft-neg-out54.6%
distribute-rgt-neg-in54.6%
distribute-lft-neg-out54.6%
sub-neg54.6%
log1p-define98.9%
Simplified98.9%
Taylor expanded in u0 around 0 86.5%
(FPCore (alpha u0) :precision binary32 (* alpha (* u0 (* alpha (+ 1.0 (* u0 0.5))))))
float code(float alpha, float u0) {
return alpha * (u0 * (alpha * (1.0f + (u0 * 0.5f))));
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = alpha * (u0 * (alpha * (1.0e0 + (u0 * 0.5e0))))
end function
function code(alpha, u0) return Float32(alpha * Float32(u0 * Float32(alpha * Float32(Float32(1.0) + Float32(u0 * Float32(0.5)))))) end
function tmp = code(alpha, u0) tmp = alpha * (u0 * (alpha * (single(1.0) + (u0 * single(0.5))))); end
\begin{array}{l}
\\
\alpha \cdot \left(u0 \cdot \left(\alpha \cdot \left(1 + u0 \cdot 0.5\right)\right)\right)
\end{array}
Initial program 54.7%
associate-*l*54.6%
distribute-lft-neg-out54.6%
distribute-rgt-neg-in54.6%
distribute-lft-neg-out54.6%
sub-neg54.6%
log1p-define98.9%
Simplified98.9%
Taylor expanded in u0 around 0 91.9%
Taylor expanded in u0 around 0 89.8%
*-commutative89.8%
associate-*l*89.8%
Simplified89.8%
Taylor expanded in u0 around 0 86.5%
associate-*r*86.5%
*-commutative86.5%
*-commutative86.5%
Simplified86.5%
Taylor expanded in alpha around 0 86.2%
*-commutative86.2%
Simplified86.2%
(FPCore (alpha u0) :precision binary32 (* alpha (* alpha (* u0 (+ 1.0 (* u0 0.5))))))
float code(float alpha, float u0) {
return alpha * (alpha * (u0 * (1.0f + (u0 * 0.5f))));
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = alpha * (alpha * (u0 * (1.0e0 + (u0 * 0.5e0))))
end function
function code(alpha, u0) return Float32(alpha * Float32(alpha * Float32(u0 * Float32(Float32(1.0) + Float32(u0 * Float32(0.5)))))) end
function tmp = code(alpha, u0) tmp = alpha * (alpha * (u0 * (single(1.0) + (u0 * single(0.5))))); end
\begin{array}{l}
\\
\alpha \cdot \left(\alpha \cdot \left(u0 \cdot \left(1 + u0 \cdot 0.5\right)\right)\right)
\end{array}
Initial program 54.7%
associate-*l*54.6%
distribute-lft-neg-out54.6%
distribute-rgt-neg-in54.6%
distribute-lft-neg-out54.6%
sub-neg54.6%
log1p-define98.9%
Simplified98.9%
Taylor expanded in u0 around 0 91.9%
Taylor expanded in u0 around 0 89.8%
*-commutative89.8%
associate-*l*89.8%
Simplified89.8%
Taylor expanded in u0 around 0 86.5%
associate-*r*86.5%
*-commutative86.5%
*-commutative86.5%
Simplified86.5%
Taylor expanded in alpha around 0 86.0%
Final simplification86.0%
(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(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*54.6%
distribute-lft-neg-out54.6%
distribute-rgt-neg-in54.6%
distribute-lft-neg-out54.6%
sub-neg54.6%
log1p-define98.9%
Simplified98.9%
Taylor expanded in u0 around 0 75.1%
herbie shell --seed 2024110
(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))))