
(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 7 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)) (/ (/ 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(log1p(Float32(-u0)) / Float32(Float32(Float32(-cos2phi) / Float32(alphax * alphax)) - Float32(Float32(sin2phi / alphay) / alphay))) end
\begin{array}{l}
\\
\frac{\mathsf{log1p}\left(-u0\right)}{\frac{-cos2phi}{alphax \cdot alphax} - \frac{\frac{sin2phi}{alphay}}{alphay}}
\end{array}
Initial program 62.7%
distribute-frac-neg62.7%
distribute-neg-frac262.7%
neg-mul-162.7%
associate-/r*62.7%
remove-double-neg62.7%
distribute-frac-neg62.7%
distribute-neg-frac262.7%
metadata-eval62.7%
/-rgt-identity62.7%
sub-neg62.7%
log1p-define98.2%
Simplified98.2%
associate-/r*98.3%
div-inv98.2%
Applied egg-rr98.2%
un-div-inv98.3%
Applied egg-rr98.3%
Final simplification98.3%
(FPCore (alphax alphay u0 cos2phi sin2phi)
:precision binary32
(let* ((t_0 (/ sin2phi (* alphay alphay))))
(if (<= t_0 0.0010000000474974513)
(/
u0
(+ (/ cos2phi (* alphax alphax)) (/ 1.0 (* alphay (/ alphay sin2phi)))))
(/ (log1p (- u0)) (- (/ (/ cos2phi alphax) alphax) t_0)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
float t_0 = sin2phi / (alphay * alphay);
float tmp;
if (t_0 <= 0.0010000000474974513f) {
tmp = u0 / ((cos2phi / (alphax * alphax)) + (1.0f / (alphay * (alphay / sin2phi))));
} else {
tmp = log1pf(-u0) / (((cos2phi / alphax) / alphax) - t_0);
}
return tmp;
}
function code(alphax, alphay, u0, cos2phi, sin2phi) t_0 = Float32(sin2phi / Float32(alphay * alphay)) tmp = Float32(0.0) if (t_0 <= Float32(0.0010000000474974513)) tmp = Float32(u0 / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(Float32(1.0) / Float32(alphay * Float32(alphay / sin2phi))))); else tmp = Float32(log1p(Float32(-u0)) / Float32(Float32(Float32(cos2phi / alphax) / alphax) - t_0)); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{sin2phi}{alphay \cdot alphay}\\
\mathbf{if}\;t\_0 \leq 0.0010000000474974513:\\
\;\;\;\;\frac{u0}{\frac{cos2phi}{alphax \cdot alphax} + \frac{1}{alphay \cdot \frac{alphay}{sin2phi}}}\\
\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{log1p}\left(-u0\right)}{\frac{\frac{cos2phi}{alphax}}{alphax} - t\_0}\\
\end{array}
\end{array}
if (/.f32 sin2phi (*.f32 alphay alphay)) < 0.00100000005Initial program 56.7%
Taylor expanded in u0 around 0 73.7%
mul-1-neg73.7%
Simplified73.7%
associate-/r*98.6%
div-inv98.5%
Applied egg-rr73.7%
clear-num73.7%
frac-times73.7%
metadata-eval73.7%
Applied egg-rr73.7%
if 0.00100000005 < (/.f32 sin2phi (*.f32 alphay alphay)) Initial program 67.5%
distribute-frac-neg67.5%
distribute-neg-frac267.5%
sub-neg67.5%
log1p-define98.0%
neg-sub098.0%
associate--r+98.0%
neg-sub098.0%
associate-/r*98.0%
distribute-neg-frac298.0%
Simplified98.0%
distribute-frac-neg298.0%
associate-/r*98.0%
add-sqr-sqrt98.0%
distribute-rgt-neg-in98.0%
sqrt-div98.0%
sqrt-prod98.0%
add-sqr-sqrt98.0%
sqrt-div98.0%
sqrt-prod98.0%
add-sqr-sqrt98.0%
Applied egg-rr98.0%
add-sqr-sqrt98.0%
sqrt-prod98.0%
sqrt-div98.0%
add-sqr-sqrt-0.0%
sqrt-unprod96.6%
sqr-neg96.6%
sqrt-unprod96.6%
add-sqr-sqrt96.6%
add-sqr-sqrt96.6%
sqrt-prod96.6%
sqrt-div96.6%
add-sqr-sqrt96.6%
associate-/r*96.6%
Applied egg-rr96.6%
Final simplification86.4%
(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(log1p(Float32(-u0)) / Float32(Float32(Float32(cos2phi / alphax) / Float32(-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 62.7%
distribute-frac-neg62.7%
distribute-neg-frac262.7%
sub-neg62.7%
log1p-define98.2%
neg-sub098.2%
associate--r+98.2%
neg-sub098.2%
associate-/r*98.2%
distribute-neg-frac298.2%
Simplified98.2%
Final simplification98.2%
(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(log1p(Float32(-u0)) / Float32(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 62.7%
distribute-frac-neg62.7%
distribute-neg-frac262.7%
neg-mul-162.7%
associate-/r*62.7%
remove-double-neg62.7%
distribute-frac-neg62.7%
distribute-neg-frac262.7%
metadata-eval62.7%
/-rgt-identity62.7%
sub-neg62.7%
log1p-define98.2%
Simplified98.2%
Final simplification98.2%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ u0 (+ (/ cos2phi (* alphax alphax)) (* (/ sin2phi alphay) (/ 1.0 alphay)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return u0 / ((cos2phi / (alphax * alphax)) + ((sin2phi / alphay) * (1.0f / 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) * (1.0e0 / alphay)))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(u0 / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(Float32(sin2phi / alphay) * Float32(Float32(1.0) / alphay)))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = u0 / ((cos2phi / (alphax * alphax)) + ((sin2phi / alphay) * (single(1.0) / alphay))); end
\begin{array}{l}
\\
\frac{u0}{\frac{cos2phi}{alphax \cdot alphax} + \frac{sin2phi}{alphay} \cdot \frac{1}{alphay}}
\end{array}
Initial program 62.7%
Taylor expanded in u0 around 0 74.5%
mul-1-neg74.5%
Simplified74.5%
associate-/r*98.3%
div-inv98.2%
Applied egg-rr74.5%
Final simplification74.5%
(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 62.7%
Taylor expanded in u0 around 0 74.5%
mul-1-neg74.5%
Simplified74.5%
associate-/r*98.3%
div-inv98.2%
Applied egg-rr74.5%
clear-num74.5%
frac-times74.5%
metadata-eval74.5%
Applied egg-rr74.5%
Final simplification74.5%
(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(sin2phi / Float32(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{sin2phi}{alphay \cdot alphay}}
\end{array}
Initial program 62.7%
Taylor expanded in u0 around 0 74.5%
mul-1-neg74.5%
Simplified74.5%
Final simplification74.5%
herbie shell --seed 2024039
(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)))))