
(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 * alpha) * Float32(-log1p(Float32(-u0)))) end
\begin{array}{l}
\\
\left(\alpha \cdot \alpha\right) \cdot \left(-\mathsf{log1p}\left(-u0\right)\right)
\end{array}
Initial program 56.7%
associate-*l*56.7%
sub-neg56.7%
log1p-def99.0%
Simplified99.0%
Taylor expanded in alpha around 0 56.7%
mul-1-neg56.7%
distribute-rgt-neg-in56.7%
unpow256.7%
sub-neg56.7%
mul-1-neg56.7%
log1p-def99.0%
mul-1-neg99.0%
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(Float32(-alpha) * Float32(alpha * log1p(Float32(-u0)))) end
\begin{array}{l}
\\
\left(-\alpha\right) \cdot \left(\alpha \cdot \mathsf{log1p}\left(-u0\right)\right)
\end{array}
Initial program 56.7%
associate-*l*56.7%
sub-neg56.7%
log1p-def99.0%
Simplified99.0%
Final simplification99.0%
(FPCore (alpha u0) :precision binary32 (+ (* alpha (* alpha u0)) (* (* alpha alpha) (* u0 (+ (* u0 (* u0 0.3333333333333333)) (* u0 0.5))))))
float code(float alpha, float u0) {
return (alpha * (alpha * u0)) + ((alpha * alpha) * (u0 * ((u0 * (u0 * 0.3333333333333333f)) + (u0 * 0.5f))));
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (alpha * (alpha * u0)) + ((alpha * alpha) * (u0 * ((u0 * (u0 * 0.3333333333333333e0)) + (u0 * 0.5e0))))
end function
function code(alpha, u0) return Float32(Float32(alpha * Float32(alpha * u0)) + Float32(Float32(alpha * alpha) * Float32(u0 * Float32(Float32(u0 * Float32(u0 * Float32(0.3333333333333333))) + Float32(u0 * Float32(0.5)))))) end
function tmp = code(alpha, u0) tmp = (alpha * (alpha * u0)) + ((alpha * alpha) * (u0 * ((u0 * (u0 * single(0.3333333333333333))) + (u0 * single(0.5))))); end
\begin{array}{l}
\\
\alpha \cdot \left(\alpha \cdot u0\right) + \left(\alpha \cdot \alpha\right) \cdot \left(u0 \cdot \left(u0 \cdot \left(u0 \cdot 0.3333333333333333\right) + u0 \cdot 0.5\right)\right)
\end{array}
Initial program 56.7%
associate-*l*56.7%
sub-neg56.7%
log1p-def99.0%
Simplified99.0%
Taylor expanded in u0 around 0 93.1%
*-commutative93.1%
+-commutative93.1%
associate-*r*93.1%
associate-*r*93.1%
distribute-rgt-out93.1%
distribute-lft-out93.1%
unpow293.1%
cube-mult93.1%
unpow293.1%
associate-*r*93.1%
distribute-rgt-out93.1%
unpow293.1%
Simplified93.1%
distribute-lft-in93.1%
associate-*r*93.2%
associate-*l*93.2%
+-commutative93.2%
*-commutative93.2%
fma-def93.2%
Applied egg-rr93.2%
fma-udef93.2%
distribute-rgt-in93.2%
Applied egg-rr93.2%
Final simplification93.2%
(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 56.7%
associate-*l*56.7%
sub-neg56.7%
log1p-def99.0%
Simplified99.0%
Taylor expanded in u0 around 0 93.1%
*-commutative93.1%
+-commutative93.1%
associate-*r*93.1%
associate-*r*93.1%
distribute-rgt-out93.1%
distribute-lft-out93.1%
unpow293.1%
cube-mult93.1%
unpow293.1%
associate-*r*93.1%
distribute-rgt-out93.1%
unpow293.1%
Simplified93.1%
Final simplification93.1%
(FPCore (alpha u0) :precision binary32 (* (* alpha alpha) (* u0 (+ (* u0 0.5) 1.0))))
float code(float alpha, float u0) {
return (alpha * alpha) * (u0 * ((u0 * 0.5f) + 1.0f));
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (alpha * alpha) * (u0 * ((u0 * 0.5e0) + 1.0e0))
end function
function code(alpha, u0) return Float32(Float32(alpha * alpha) * Float32(u0 * Float32(Float32(u0 * Float32(0.5)) + Float32(1.0)))) end
function tmp = code(alpha, u0) tmp = (alpha * alpha) * (u0 * ((u0 * single(0.5)) + single(1.0))); end
\begin{array}{l}
\\
\left(\alpha \cdot \alpha\right) \cdot \left(u0 \cdot \left(u0 \cdot 0.5 + 1\right)\right)
\end{array}
Initial program 56.7%
associate-*l*56.7%
sub-neg56.7%
log1p-def99.0%
Simplified99.0%
Taylor expanded in u0 around 0 93.1%
associate-+r+93.1%
+-commutative93.1%
associate-*r*93.1%
*-commutative93.1%
associate-*r*93.1%
associate-*r*93.1%
distribute-rgt-out93.0%
distribute-lft-out93.0%
associate-+l+93.1%
mul-1-neg93.1%
unsub-neg93.1%
*-commutative93.1%
*-commutative93.1%
unpow393.1%
unpow293.1%
associate-*l*93.1%
distribute-lft-out93.1%
unpow293.1%
Simplified93.1%
Taylor expanded in u0 around 0 88.9%
+-commutative88.9%
unpow288.9%
associate-*r*88.9%
metadata-eval88.9%
distribute-lft-neg-in88.9%
unpow288.9%
unpow288.9%
distribute-rgt-out88.9%
unpow288.9%
*-commutative88.9%
distribute-rgt-neg-in88.9%
unpow288.9%
metadata-eval88.9%
associate-*l*88.9%
Simplified88.9%
*-commutative88.9%
distribute-lft1-in88.6%
Applied egg-rr88.6%
Final simplification88.6%
(FPCore (alpha u0) :precision binary32 (* (* alpha alpha) (+ u0 (* 0.5 (* u0 u0)))))
float code(float alpha, float u0) {
return (alpha * alpha) * (u0 + (0.5f * (u0 * u0)));
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (alpha * alpha) * (u0 + (0.5e0 * (u0 * u0)))
end function
function code(alpha, u0) return Float32(Float32(alpha * alpha) * Float32(u0 + Float32(Float32(0.5) * Float32(u0 * u0)))) end
function tmp = code(alpha, u0) tmp = (alpha * alpha) * (u0 + (single(0.5) * (u0 * u0))); end
\begin{array}{l}
\\
\left(\alpha \cdot \alpha\right) \cdot \left(u0 + 0.5 \cdot \left(u0 \cdot u0\right)\right)
\end{array}
Initial program 56.7%
associate-*l*56.7%
sub-neg56.7%
log1p-def99.0%
Simplified99.0%
Taylor expanded in u0 around 0 88.9%
associate-*r*88.9%
distribute-rgt-out88.9%
unpow288.9%
unpow288.9%
Simplified88.9%
Final simplification88.9%
(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 56.7%
associate-*l*56.7%
sub-neg56.7%
log1p-def99.0%
Simplified99.0%
Taylor expanded in u0 around 0 74.3%
*-commutative74.3%
unpow274.3%
associate-*l*74.3%
Simplified74.3%
Final simplification74.3%
(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 56.7%
associate-*l*56.7%
sub-neg56.7%
log1p-def99.0%
Simplified99.0%
Taylor expanded in u0 around 0 74.3%
*-commutative74.3%
unpow274.3%
Simplified74.3%
Final simplification74.3%
herbie shell --seed 2023279
(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))))