
(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 55.3%
*-commutative55.3%
sub-neg55.3%
log1p-def99.1%
Simplified99.1%
Final simplification99.1%
(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 55.3%
associate-*l*55.3%
sub-neg55.3%
log1p-def99.0%
Simplified99.0%
Final simplification99.0%
(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 55.3%
associate-*l*55.3%
sub-neg55.3%
log1p-def99.0%
Simplified99.0%
Taylor expanded in u0 around 0 92.0%
*-commutative92.0%
+-commutative92.0%
associate-*r*92.0%
associate-*r*92.0%
distribute-rgt-out92.0%
distribute-lft-out91.9%
unpow291.9%
+-commutative91.9%
cube-mult91.9%
unpow291.9%
associate-*r*91.9%
distribute-rgt-out91.9%
unpow291.9%
*-commutative91.9%
Simplified91.9%
Final simplification91.9%
(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(alpha * Float32(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}
\\
\alpha \cdot \left(\alpha \cdot \left(u0 - \left(u0 \cdot u0\right) \cdot \left(-0.5 + u0 \cdot -0.3333333333333333\right)\right)\right)
\end{array}
Initial program 55.3%
associate-*l*55.3%
sub-neg55.3%
log1p-def99.0%
Simplified99.0%
Taylor expanded in u0 around 0 91.9%
*-commutative91.9%
*-commutative91.9%
associate-*l*91.9%
*-commutative91.9%
associate-*r*91.9%
associate-*r*91.9%
distribute-rgt-out92.0%
distribute-lft-out91.9%
+-commutative91.9%
associate-+l+91.9%
+-commutative91.9%
mul-1-neg91.9%
unsub-neg91.9%
Simplified91.9%
Final simplification91.9%
(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 55.3%
associate-*l*55.3%
sub-neg55.3%
log1p-def99.0%
Simplified99.0%
Taylor expanded in u0 around 0 88.3%
associate-*r*88.3%
distribute-rgt-out88.2%
unpow288.2%
unpow288.2%
Simplified88.2%
Final simplification88.2%
(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(alpha * Float32(alpha * Float32(u0 - Float32(u0 * Float32(u0 * Float32(-0.5)))))) end
function tmp = code(alpha, u0) tmp = alpha * (alpha * (u0 - (u0 * (u0 * single(-0.5))))); end
\begin{array}{l}
\\
\alpha \cdot \left(\alpha \cdot \left(u0 - u0 \cdot \left(u0 \cdot -0.5\right)\right)\right)
\end{array}
Initial program 55.3%
associate-*l*55.3%
sub-neg55.3%
log1p-def99.0%
Simplified99.0%
Taylor expanded in u0 around 0 88.3%
+-commutative88.3%
mul-1-neg88.3%
unsub-neg88.3%
associate-*r*88.3%
distribute-rgt-out--88.3%
*-commutative88.3%
unpow288.3%
associate-*l*88.3%
Simplified88.3%
Final simplification88.3%
(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 55.3%
associate-*l*55.3%
sub-neg55.3%
log1p-def99.0%
Simplified99.0%
Taylor expanded in u0 around 0 75.0%
*-commutative75.0%
unpow275.0%
Simplified75.0%
Final simplification75.0%
herbie shell --seed 2023182
(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))))