
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (- (log (- 1.0 u0))) (+ (/ cos2phi (* alphax alphax)) (/ sin2phi (* alphay alphay)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return -logf((1.0f - u0)) / ((cos2phi / (alphax * alphax)) + (sin2phi / (alphay * alphay)));
}
real(4) function code(alphax, alphay, u0, cos2phi, sin2phi)
real(4), intent (in) :: alphax
real(4), intent (in) :: alphay
real(4), intent (in) :: u0
real(4), intent (in) :: cos2phi
real(4), intent (in) :: sin2phi
code = -log((1.0e0 - u0)) / ((cos2phi / (alphax * alphax)) + (sin2phi / (alphay * alphay)))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(-log(Float32(Float32(1.0) - u0))) / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(sin2phi / Float32(alphay * alphay)))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = -log((single(1.0) - u0)) / ((cos2phi / (alphax * alphax)) + (sin2phi / (alphay * alphay))); end
\begin{array}{l}
\\
\frac{-\log \left(1 - u0\right)}{\frac{cos2phi}{alphax \cdot alphax} + \frac{sin2phi}{alphay \cdot alphay}}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 8 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (- (log (- 1.0 u0))) (+ (/ cos2phi (* alphax alphax)) (/ sin2phi (* alphay alphay)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return -logf((1.0f - u0)) / ((cos2phi / (alphax * alphax)) + (sin2phi / (alphay * alphay)));
}
real(4) function code(alphax, alphay, u0, cos2phi, sin2phi)
real(4), intent (in) :: alphax
real(4), intent (in) :: alphay
real(4), intent (in) :: u0
real(4), intent (in) :: cos2phi
real(4), intent (in) :: sin2phi
code = -log((1.0e0 - u0)) / ((cos2phi / (alphax * alphax)) + (sin2phi / (alphay * alphay)))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(-log(Float32(Float32(1.0) - u0))) / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(sin2phi / Float32(alphay * alphay)))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = -log((single(1.0) - u0)) / ((cos2phi / (alphax * alphax)) + (sin2phi / (alphay * alphay))); end
\begin{array}{l}
\\
\frac{-\log \left(1 - u0\right)}{\frac{cos2phi}{alphax \cdot alphax} + \frac{sin2phi}{alphay \cdot alphay}}
\end{array}
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (- (log1p (- u0))) (+ (/ (/ cos2phi alphax) alphax) (* (pow alphay -2.0) sin2phi))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return -log1pf(-u0) / (((cos2phi / alphax) / alphax) + (powf(alphay, -2.0f) * sin2phi));
}
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(-log1p(Float32(-u0))) / Float32(Float32(Float32(cos2phi / alphax) / alphax) + Float32((alphay ^ Float32(-2.0)) * sin2phi))) end
\begin{array}{l}
\\
\frac{-\mathsf{log1p}\left(-u0\right)}{\frac{\frac{cos2phi}{alphax}}{alphax} + {alphay}^{-2} \cdot sin2phi}
\end{array}
Initial program 59.6%
sub-neg59.6%
log1p-def98.5%
Simplified98.5%
associate-/r*98.6%
div-inv98.6%
Applied egg-rr98.6%
un-div-inv98.6%
Applied egg-rr98.6%
clear-num98.4%
associate-/r/98.4%
pow298.4%
pow-flip98.6%
metadata-eval98.6%
Applied egg-rr98.6%
Final simplification98.6%
(FPCore (alphax alphay u0 cos2phi sin2phi)
:precision binary32
(let* ((t_0 (/ alphax (/ cos2phi alphax))))
(if (<= (/ sin2phi (* alphay alphay)) 0.05000000074505806)
(/ u0 (/ (+ alphay (* t_0 (/ sin2phi alphay))) (* alphay t_0)))
(/ (* alphay (- alphay)) (/ sin2phi (log1p (- u0)))))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
float t_0 = alphax / (cos2phi / alphax);
float tmp;
if ((sin2phi / (alphay * alphay)) <= 0.05000000074505806f) {
tmp = u0 / ((alphay + (t_0 * (sin2phi / alphay))) / (alphay * t_0));
} else {
tmp = (alphay * -alphay) / (sin2phi / log1pf(-u0));
}
return tmp;
}
function code(alphax, alphay, u0, cos2phi, sin2phi) t_0 = Float32(alphax / Float32(cos2phi / alphax)) tmp = Float32(0.0) if (Float32(sin2phi / Float32(alphay * alphay)) <= Float32(0.05000000074505806)) tmp = Float32(u0 / Float32(Float32(alphay + Float32(t_0 * Float32(sin2phi / alphay))) / Float32(alphay * t_0))); else tmp = Float32(Float32(alphay * Float32(-alphay)) / Float32(sin2phi / log1p(Float32(-u0)))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{alphax}{\frac{cos2phi}{alphax}}\\
\mathbf{if}\;\frac{sin2phi}{alphay \cdot alphay} \leq 0.05000000074505806:\\
\;\;\;\;\frac{u0}{\frac{alphay + t_0 \cdot \frac{sin2phi}{alphay}}{alphay \cdot t_0}}\\
\mathbf{else}:\\
\;\;\;\;\frac{alphay \cdot \left(-alphay\right)}{\frac{sin2phi}{\mathsf{log1p}\left(-u0\right)}}\\
\end{array}
\end{array}
if (/.f32 sin2phi (*.f32 alphay alphay)) < 0.0500000007Initial program 53.8%
Taylor expanded in u0 around 0 75.5%
mul-1-neg75.5%
Simplified75.5%
clear-num98.7%
associate-/r/98.6%
pow298.6%
pow-flip98.7%
metadata-eval98.7%
Applied egg-rr75.6%
*-commutative75.6%
metadata-eval75.6%
pow-flip75.5%
pow275.5%
div-inv75.5%
associate-/r*75.5%
Applied egg-rr75.5%
associate-/r*75.6%
clear-num75.6%
frac-add75.7%
*-un-lft-identity75.7%
Applied egg-rr75.7%
if 0.0500000007 < (/.f32 sin2phi (*.f32 alphay alphay)) Initial program 63.2%
Taylor expanded in cos2phi around 0 62.4%
mul-1-neg62.4%
associate-/l*62.0%
distribute-neg-frac62.0%
sub-neg62.0%
mul-1-neg62.0%
log1p-def95.1%
mul-1-neg95.1%
Simplified95.1%
unpow295.1%
Applied egg-rr95.1%
Final simplification87.6%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (- (log1p (- u0))) (+ (/ sin2phi (* alphay alphay)) (/ cos2phi (* alphax alphax)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return -log1pf(-u0) / ((sin2phi / (alphay * alphay)) + (cos2phi / (alphax * alphax)));
}
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(-log1p(Float32(-u0))) / Float32(Float32(sin2phi / Float32(alphay * alphay)) + Float32(cos2phi / Float32(alphax * alphax)))) end
\begin{array}{l}
\\
\frac{-\mathsf{log1p}\left(-u0\right)}{\frac{sin2phi}{alphay \cdot alphay} + \frac{cos2phi}{alphax \cdot alphax}}
\end{array}
Initial program 59.6%
sub-neg59.6%
log1p-def98.5%
Simplified98.5%
Final simplification98.5%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (- (log1p (- u0))) (+ (/ (/ cos2phi alphax) alphax) (/ sin2phi (* alphay alphay)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return -log1pf(-u0) / (((cos2phi / alphax) / alphax) + (sin2phi / (alphay * alphay)));
}
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(-log1p(Float32(-u0))) / Float32(Float32(Float32(cos2phi / alphax) / alphax) + Float32(sin2phi / Float32(alphay * alphay)))) end
\begin{array}{l}
\\
\frac{-\mathsf{log1p}\left(-u0\right)}{\frac{\frac{cos2phi}{alphax}}{alphax} + \frac{sin2phi}{alphay \cdot alphay}}
\end{array}
Initial program 59.6%
sub-neg59.6%
log1p-def98.5%
Simplified98.5%
associate-/r*98.6%
div-inv98.6%
Applied egg-rr98.6%
un-div-inv98.6%
Applied egg-rr98.6%
Final simplification98.6%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ u0 (/ (+ (* alphax (/ sin2phi alphay)) (* (/ cos2phi alphax) alphay)) (* alphax alphay))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return u0 / (((alphax * (sin2phi / alphay)) + ((cos2phi / alphax) * alphay)) / (alphax * alphay));
}
real(4) function code(alphax, alphay, u0, cos2phi, sin2phi)
real(4), intent (in) :: alphax
real(4), intent (in) :: alphay
real(4), intent (in) :: u0
real(4), intent (in) :: cos2phi
real(4), intent (in) :: sin2phi
code = u0 / (((alphax * (sin2phi / alphay)) + ((cos2phi / alphax) * alphay)) / (alphax * alphay))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(u0 / Float32(Float32(Float32(alphax * Float32(sin2phi / alphay)) + Float32(Float32(cos2phi / alphax) * alphay)) / Float32(alphax * alphay))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = u0 / (((alphax * (sin2phi / alphay)) + ((cos2phi / alphax) * alphay)) / (alphax * alphay)); end
\begin{array}{l}
\\
\frac{u0}{\frac{alphax \cdot \frac{sin2phi}{alphay} + \frac{cos2phi}{alphax} \cdot alphay}{alphax \cdot alphay}}
\end{array}
Initial program 59.6%
Taylor expanded in u0 around 0 76.5%
mul-1-neg76.5%
Simplified76.5%
+-commutative76.5%
associate-/r*76.5%
associate-/r*76.6%
frac-add76.6%
Applied egg-rr76.6%
Final simplification76.6%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ u0 (+ (/ cos2phi (* alphax alphax)) (/ 1.0 (* alphay (/ alphay sin2phi))))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return u0 / ((cos2phi / (alphax * alphax)) + (1.0f / (alphay * (alphay / sin2phi))));
}
real(4) function code(alphax, alphay, u0, cos2phi, sin2phi)
real(4), intent (in) :: alphax
real(4), intent (in) :: alphay
real(4), intent (in) :: u0
real(4), intent (in) :: cos2phi
real(4), intent (in) :: sin2phi
code = u0 / ((cos2phi / (alphax * alphax)) + (1.0e0 / (alphay * (alphay / sin2phi))))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(u0 / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(Float32(1.0) / Float32(alphay * Float32(alphay / sin2phi))))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = u0 / ((cos2phi / (alphax * alphax)) + (single(1.0) / (alphay * (alphay / sin2phi)))); end
\begin{array}{l}
\\
\frac{u0}{\frac{cos2phi}{alphax \cdot alphax} + \frac{1}{alphay \cdot \frac{alphay}{sin2phi}}}
\end{array}
Initial program 59.6%
Taylor expanded in u0 around 0 76.5%
mul-1-neg76.5%
Simplified76.5%
clear-num98.4%
associate-/r/98.4%
pow298.4%
pow-flip98.6%
metadata-eval98.6%
Applied egg-rr76.6%
*-commutative76.6%
metadata-eval76.6%
pow-flip76.5%
pow276.5%
div-inv76.5%
associate-/r*76.5%
Applied egg-rr76.5%
clear-num76.5%
inv-pow76.5%
Applied egg-rr76.5%
unpow-176.5%
associate-/r/76.6%
Simplified76.6%
Final simplification76.6%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ u0 (+ (/ sin2phi (* alphay alphay)) (/ cos2phi (* alphax alphax)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return u0 / ((sin2phi / (alphay * alphay)) + (cos2phi / (alphax * alphax)));
}
real(4) function code(alphax, alphay, u0, cos2phi, sin2phi)
real(4), intent (in) :: alphax
real(4), intent (in) :: alphay
real(4), intent (in) :: u0
real(4), intent (in) :: cos2phi
real(4), intent (in) :: sin2phi
code = u0 / ((sin2phi / (alphay * alphay)) + (cos2phi / (alphax * alphax)))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(u0 / Float32(Float32(sin2phi / Float32(alphay * alphay)) + Float32(cos2phi / Float32(alphax * alphax)))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = u0 / ((sin2phi / (alphay * alphay)) + (cos2phi / (alphax * alphax))); end
\begin{array}{l}
\\
\frac{u0}{\frac{sin2phi}{alphay \cdot alphay} + \frac{cos2phi}{alphax \cdot alphax}}
\end{array}
Initial program 59.6%
Taylor expanded in u0 around 0 76.5%
mul-1-neg76.5%
Simplified76.5%
Final simplification76.5%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ u0 (+ (/ cos2phi (* alphax alphax)) (/ (/ sin2phi alphay) alphay))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return u0 / ((cos2phi / (alphax * alphax)) + ((sin2phi / alphay) / alphay));
}
real(4) function code(alphax, alphay, u0, cos2phi, sin2phi)
real(4), intent (in) :: alphax
real(4), intent (in) :: alphay
real(4), intent (in) :: u0
real(4), intent (in) :: cos2phi
real(4), intent (in) :: sin2phi
code = u0 / ((cos2phi / (alphax * alphax)) + ((sin2phi / alphay) / alphay))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(u0 / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(Float32(sin2phi / alphay) / alphay))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = u0 / ((cos2phi / (alphax * alphax)) + ((sin2phi / alphay) / alphay)); end
\begin{array}{l}
\\
\frac{u0}{\frac{cos2phi}{alphax \cdot alphax} + \frac{\frac{sin2phi}{alphay}}{alphay}}
\end{array}
Initial program 59.6%
Taylor expanded in u0 around 0 76.5%
mul-1-neg76.5%
Simplified76.5%
clear-num98.4%
associate-/r/98.4%
pow298.4%
pow-flip98.6%
metadata-eval98.6%
Applied egg-rr76.6%
*-commutative76.6%
metadata-eval76.6%
pow-flip76.5%
pow276.5%
div-inv76.5%
associate-/r*76.5%
Applied egg-rr76.5%
Final simplification76.5%
herbie shell --seed 2024024
(FPCore (alphax alphay u0 cos2phi sin2phi)
:name "Beckmann Distribution sample, tan2theta, alphax != alphay, u1 <= 0.5"
:precision binary32
:pre (and (and (and (and (and (<= 0.0001 alphax) (<= alphax 1.0)) (and (<= 0.0001 alphay) (<= alphay 1.0))) (and (<= 2.328306437e-10 u0) (<= u0 1.0))) (and (<= 0.0 cos2phi) (<= cos2phi 1.0))) (<= 0.0 sin2phi))
(/ (- (log (- 1.0 u0))) (+ (/ cos2phi (* alphax alphax)) (/ sin2phi (* alphay alphay)))))