
(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 9 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 (* alphay (/ (* (log1p (- u0)) (* alphax (- alphax))) (fma cos2phi alphay (* (* alphax alphax) (/ sin2phi alphay))))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return alphay * ((log1pf(-u0) * (alphax * -alphax)) / fmaf(cos2phi, alphay, ((alphax * alphax) * (sin2phi / alphay))));
}
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(alphay * Float32(Float32(log1p(Float32(-u0)) * Float32(alphax * Float32(-alphax))) / fma(cos2phi, alphay, Float32(Float32(alphax * alphax) * Float32(sin2phi / alphay))))) end
\begin{array}{l}
\\
alphay \cdot \frac{\mathsf{log1p}\left(-u0\right) \cdot \left(alphax \cdot \left(-alphax\right)\right)}{\mathsf{fma}\left(cos2phi, alphay, \left(alphax \cdot alphax\right) \cdot \frac{sin2phi}{alphay}\right)}
\end{array}
Initial program 59.3%
sub-neg59.3%
log1p-def98.2%
Simplified98.2%
associate-/r*98.3%
div-inv98.2%
Applied egg-rr98.2%
un-div-inv98.3%
Applied egg-rr98.3%
associate-/r*98.4%
associate-/r*98.3%
+-commutative98.3%
associate-/r*98.4%
associate-/r*98.3%
frac-add98.0%
Applied egg-rr98.0%
div-inv97.8%
fma-def97.9%
*-commutative97.9%
*-commutative97.9%
Applied egg-rr97.9%
associate-*r/98.1%
*-rgt-identity98.1%
distribute-neg-frac98.1%
associate-/r/98.5%
distribute-lft-neg-in98.5%
distribute-frac-neg98.5%
unpow298.5%
associate-*r*98.4%
*-commutative98.4%
Simplified98.3%
Final simplification98.3%
(FPCore (alphax alphay u0 cos2phi sin2phi)
:precision binary32
(let* ((t_0 (/ sin2phi (* alphay alphay))))
(if (<= t_0 50.0)
(/
(- u0 (* (* u0 u0) -0.5))
(+ (/ cos2phi (* alphax alphax)) (/ 1.0 (/ (* alphay alphay) sin2phi))))
(/ (- (log1p (- u0))) 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 <= 50.0f) {
tmp = (u0 - ((u0 * u0) * -0.5f)) / ((cos2phi / (alphax * alphax)) + (1.0f / ((alphay * alphay) / sin2phi)));
} else {
tmp = -log1pf(-u0) / 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(50.0)) tmp = Float32(Float32(u0 - Float32(Float32(u0 * u0) * Float32(-0.5))) / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(Float32(1.0) / Float32(Float32(alphay * alphay) / sin2phi)))); else tmp = Float32(Float32(-log1p(Float32(-u0))) / t_0); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{sin2phi}{alphay \cdot alphay}\\
\mathbf{if}\;t_0 \leq 50:\\
\;\;\;\;\frac{u0 - \left(u0 \cdot u0\right) \cdot -0.5}{\frac{cos2phi}{alphax \cdot alphax} + \frac{1}{\frac{alphay \cdot alphay}{sin2phi}}}\\
\mathbf{else}:\\
\;\;\;\;\frac{-\mathsf{log1p}\left(-u0\right)}{t_0}\\
\end{array}
\end{array}
if (/.f32 sin2phi (*.f32 alphay alphay)) < 50Initial program 53.7%
sub-neg53.7%
log1p-def98.6%
Simplified98.6%
associate-/r*98.6%
div-inv98.6%
Applied egg-rr98.6%
un-div-inv98.6%
associate-/r*98.6%
clear-num98.6%
Applied egg-rr98.6%
Taylor expanded in u0 around 0 89.2%
+-commutative89.2%
neg-mul-189.2%
unsub-neg89.2%
*-commutative89.2%
unpow289.2%
Simplified89.2%
if 50 < (/.f32 sin2phi (*.f32 alphay alphay)) Initial program 65.2%
sub-neg65.2%
log1p-def97.8%
Simplified97.8%
associate-/r*97.8%
div-inv97.8%
Applied egg-rr97.8%
Taylor expanded in cos2phi around 0 97.7%
unpow297.7%
Simplified97.7%
Final simplification93.3%
(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(cos2phi / Float32(alphax * alphax)) + Float32(sin2phi / Float32(alphay * alphay)))) end
\begin{array}{l}
\\
\frac{-\mathsf{log1p}\left(-u0\right)}{\frac{cos2phi}{alphax \cdot alphax} + \frac{sin2phi}{alphay \cdot alphay}}
\end{array}
Initial program 59.3%
sub-neg59.3%
log1p-def98.2%
Simplified98.2%
Final simplification98.2%
(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(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 59.3%
sub-neg59.3%
log1p-def98.2%
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
(if (<= (- 1.0 u0) 0.9945999979972839)
(/ (* alphay (- alphay)) (/ sin2phi (log1p (- u0))))
(/
(- u0 (* (* u0 u0) -0.5))
(+ (/ cos2phi (* alphax alphax)) (/ 1.0 (/ (* alphay alphay) sin2phi))))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
float tmp;
if ((1.0f - u0) <= 0.9945999979972839f) {
tmp = (alphay * -alphay) / (sin2phi / log1pf(-u0));
} else {
tmp = (u0 - ((u0 * u0) * -0.5f)) / ((cos2phi / (alphax * alphax)) + (1.0f / ((alphay * alphay) / sin2phi)));
}
return tmp;
}
function code(alphax, alphay, u0, cos2phi, sin2phi) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.9945999979972839)) tmp = Float32(Float32(alphay * Float32(-alphay)) / Float32(sin2phi / log1p(Float32(-u0)))); else tmp = Float32(Float32(u0 - Float32(Float32(u0 * u0) * Float32(-0.5))) / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(Float32(1.0) / Float32(Float32(alphay * alphay) / sin2phi)))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.9945999979972839:\\
\;\;\;\;\frac{alphay \cdot \left(-alphay\right)}{\frac{sin2phi}{\mathsf{log1p}\left(-u0\right)}}\\
\mathbf{else}:\\
\;\;\;\;\frac{u0 - \left(u0 \cdot u0\right) \cdot -0.5}{\frac{cos2phi}{alphax \cdot alphax} + \frac{1}{\frac{alphay \cdot alphay}{sin2phi}}}\\
\end{array}
\end{array}
if (-.f32 1 u0) < 0.994599998Initial program 91.6%
sub-neg91.6%
log1p-def96.7%
Simplified96.7%
Taylor expanded in cos2phi around 0 78.6%
mul-1-neg78.6%
unpow278.6%
associate-/l*78.7%
distribute-neg-frac78.7%
distribute-rgt-neg-out78.7%
sub-neg78.7%
log1p-def82.3%
Simplified82.3%
if 0.994599998 < (-.f32 1 u0) Initial program 49.2%
sub-neg49.2%
log1p-def98.7%
Simplified98.7%
associate-/r*98.7%
div-inv98.5%
Applied egg-rr98.5%
un-div-inv98.7%
associate-/r*98.7%
clear-num98.6%
Applied egg-rr98.6%
Taylor expanded in u0 around 0 97.5%
+-commutative97.5%
neg-mul-197.5%
unsub-neg97.5%
*-commutative97.5%
unpow297.5%
Simplified97.5%
Final simplification93.9%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (- u0 (* (* u0 u0) -0.5)) (+ (/ cos2phi (* alphax alphax)) (/ 1.0 (/ (* alphay alphay) sin2phi)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return (u0 - ((u0 * u0) * -0.5f)) / ((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 - ((u0 * u0) * (-0.5e0))) / ((cos2phi / (alphax * alphax)) + (1.0e0 / ((alphay * alphay) / sin2phi)))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(u0 - Float32(Float32(u0 * u0) * Float32(-0.5))) / Float32(Float32(cos2phi / Float32(alphax * alphax)) + Float32(Float32(1.0) / Float32(Float32(alphay * alphay) / sin2phi)))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = (u0 - ((u0 * u0) * single(-0.5))) / ((cos2phi / (alphax * alphax)) + (single(1.0) / ((alphay * alphay) / sin2phi))); end
\begin{array}{l}
\\
\frac{u0 - \left(u0 \cdot u0\right) \cdot -0.5}{\frac{cos2phi}{alphax \cdot alphax} + \frac{1}{\frac{alphay \cdot alphay}{sin2phi}}}
\end{array}
Initial program 59.3%
sub-neg59.3%
log1p-def98.2%
Simplified98.2%
associate-/r*98.3%
div-inv98.2%
Applied egg-rr98.2%
un-div-inv98.3%
associate-/r*98.2%
clear-num98.2%
Applied egg-rr98.2%
Taylor expanded in u0 around 0 87.8%
+-commutative87.8%
neg-mul-187.8%
unsub-neg87.8%
*-commutative87.8%
unpow287.8%
Simplified87.8%
Final simplification87.8%
(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 59.3%
sub-neg59.3%
log1p-def98.2%
Simplified98.2%
Taylor expanded in u0 around 0 76.1%
unpow276.1%
unpow276.1%
Simplified76.1%
Final simplification76.1%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (if (<= sin2phi 4.999999841327613e-22) (* alphax (* alphax (/ u0 cos2phi))) (* (* alphay alphay) (/ u0 sin2phi))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
float tmp;
if (sin2phi <= 4.999999841327613e-22f) {
tmp = alphax * (alphax * (u0 / cos2phi));
} else {
tmp = (alphay * alphay) * (u0 / sin2phi);
}
return tmp;
}
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
real(4) :: tmp
if (sin2phi <= 4.999999841327613e-22) then
tmp = alphax * (alphax * (u0 / cos2phi))
else
tmp = (alphay * alphay) * (u0 / sin2phi)
end if
code = tmp
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) tmp = Float32(0.0) if (sin2phi <= Float32(4.999999841327613e-22)) tmp = Float32(alphax * Float32(alphax * Float32(u0 / cos2phi))); else tmp = Float32(Float32(alphay * alphay) * Float32(u0 / sin2phi)); end return tmp end
function tmp_2 = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = single(0.0); if (sin2phi <= single(4.999999841327613e-22)) tmp = alphax * (alphax * (u0 / cos2phi)); else tmp = (alphay * alphay) * (u0 / sin2phi); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;sin2phi \leq 4.999999841327613 \cdot 10^{-22}:\\
\;\;\;\;alphax \cdot \left(alphax \cdot \frac{u0}{cos2phi}\right)\\
\mathbf{else}:\\
\;\;\;\;\left(alphay \cdot alphay\right) \cdot \frac{u0}{sin2phi}\\
\end{array}
\end{array}
if sin2phi < 4.9999998e-22Initial program 57.7%
sub-neg57.7%
log1p-def98.7%
Simplified98.7%
Taylor expanded in u0 around 0 73.7%
unpow273.7%
unpow273.7%
Simplified73.7%
Taylor expanded in cos2phi around inf 59.1%
*-lft-identity59.1%
times-frac59.0%
/-rgt-identity59.0%
unpow259.0%
Simplified59.0%
Taylor expanded in alphax around 0 59.1%
unpow259.1%
associate-*r/59.0%
associate-*l*59.2%
Simplified59.2%
if 4.9999998e-22 < sin2phi Initial program 59.9%
sub-neg59.9%
log1p-def98.1%
Simplified98.1%
Taylor expanded in u0 around 0 76.9%
unpow276.9%
unpow276.9%
Simplified76.9%
Taylor expanded in cos2phi around 0 71.4%
unpow271.4%
*-lft-identity71.4%
times-frac71.4%
/-rgt-identity71.4%
Simplified71.4%
Final simplification68.3%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (* alphax (* alphax (/ u0 cos2phi))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return alphax * (alphax * (u0 / cos2phi));
}
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 = alphax * (alphax * (u0 / cos2phi))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(alphax * Float32(alphax * Float32(u0 / cos2phi))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = alphax * (alphax * (u0 / cos2phi)); end
\begin{array}{l}
\\
alphax \cdot \left(alphax \cdot \frac{u0}{cos2phi}\right)
\end{array}
Initial program 59.3%
sub-neg59.3%
log1p-def98.2%
Simplified98.2%
Taylor expanded in u0 around 0 76.1%
unpow276.1%
unpow276.1%
Simplified76.1%
Taylor expanded in cos2phi around inf 24.1%
*-lft-identity24.1%
times-frac24.1%
/-rgt-identity24.1%
unpow224.1%
Simplified24.1%
Taylor expanded in alphax around 0 24.1%
unpow224.1%
associate-*r/24.1%
associate-*l*24.1%
Simplified24.1%
Final simplification24.1%
herbie shell --seed 2023271
(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)))))