
(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 10 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))) (fma cos2phi (pow alphax -2.0) (* sin2phi (pow alphay -2.0)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return -log1pf(-u0) / fmaf(cos2phi, powf(alphax, -2.0f), (sin2phi * powf(alphay, -2.0f)));
}
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(-log1p(Float32(-u0))) / fma(cos2phi, (alphax ^ Float32(-2.0)), Float32(sin2phi * (alphay ^ Float32(-2.0))))) end
\begin{array}{l}
\\
\frac{-\mathsf{log1p}\left(-u0\right)}{\mathsf{fma}\left(cos2phi, {alphax}^{-2}, sin2phi \cdot {alphay}^{-2}\right)}
\end{array}
Initial program 59.9%
distribute-frac-neg59.9%
distribute-neg-frac259.9%
sub-neg59.9%
log1p-define98.1%
neg-sub098.1%
associate--r+98.1%
neg-sub098.1%
associate-/r*98.2%
distribute-neg-frac298.2%
Simplified98.2%
Applied egg-rr97.0%
distribute-rgt-neg-out97.0%
unpow297.0%
rem-3cbrt-lft98.2%
fma-define98.2%
+-commutative98.2%
fma-define98.2%
Simplified98.2%
Final simplification98.2%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (- (log1p (- u0))) (fma cos2phi (pow alphax -2.0) (/ (/ sin2phi alphay) alphay))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return -log1pf(-u0) / fmaf(cos2phi, powf(alphax, -2.0f), ((sin2phi / alphay) / alphay));
}
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(-log1p(Float32(-u0))) / fma(cos2phi, (alphax ^ Float32(-2.0)), Float32(Float32(sin2phi / alphay) / alphay))) end
\begin{array}{l}
\\
\frac{-\mathsf{log1p}\left(-u0\right)}{\mathsf{fma}\left(cos2phi, {alphax}^{-2}, \frac{\frac{sin2phi}{alphay}}{alphay}\right)}
\end{array}
Initial program 59.9%
distribute-frac-neg59.9%
distribute-neg-frac259.9%
sub-neg59.9%
log1p-define98.1%
neg-sub098.1%
associate--r+98.1%
neg-sub098.1%
associate-/r*98.2%
distribute-neg-frac298.2%
Simplified98.2%
Applied egg-rr97.0%
distribute-rgt-neg-out97.0%
unpow297.0%
rem-3cbrt-lft98.2%
fma-define98.2%
+-commutative98.2%
fma-define98.2%
Simplified98.2%
metadata-eval98.2%
pow-flip98.2%
div-inv98.2%
pow298.2%
associate-/r*98.2%
Applied egg-rr98.2%
Final simplification98.2%
(FPCore (alphax alphay u0 cos2phi sin2phi)
:precision binary32
(let* ((t_0 (/ sin2phi (* alphay alphay))))
(if (<= sin2phi 400000.0)
(/
(* u0 (- 1.0 (* u0 (- (* u0 (- (* u0 -0.25) 0.3333333333333333)) 0.5))))
(+ t_0 (/ cos2phi (* alphax alphax))))
(/ (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 (sin2phi <= 400000.0f) {
tmp = (u0 * (1.0f - (u0 * ((u0 * ((u0 * -0.25f) - 0.3333333333333333f)) - 0.5f)))) / (t_0 + (cos2phi / (alphax * alphax)));
} 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 (sin2phi <= Float32(400000.0)) tmp = Float32(Float32(u0 * Float32(Float32(1.0) - Float32(u0 * Float32(Float32(u0 * Float32(Float32(u0 * Float32(-0.25)) - Float32(0.3333333333333333))) - Float32(0.5))))) / Float32(t_0 + Float32(cos2phi / Float32(alphax * alphax)))); 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}\;sin2phi \leq 400000:\\
\;\;\;\;\frac{u0 \cdot \left(1 - u0 \cdot \left(u0 \cdot \left(u0 \cdot -0.25 - 0.3333333333333333\right) - 0.5\right)\right)}{t\_0 + \frac{cos2phi}{alphax \cdot alphax}}\\
\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{log1p}\left(-u0\right)}{\frac{\frac{cos2phi}{alphax}}{alphax} - t\_0}\\
\end{array}
\end{array}
if sin2phi < 4e5Initial program 54.0%
Taylor expanded in u0 around 0 94.4%
if 4e5 < sin2phi Initial program 67.1%
distribute-frac-neg67.1%
distribute-neg-frac267.1%
sub-neg67.1%
log1p-define97.6%
neg-sub097.6%
associate--r+97.6%
neg-sub097.6%
associate-/r*97.6%
distribute-neg-frac297.6%
Simplified97.6%
add-sqr-sqrt-0.0%
sqrt-unprod97.6%
sqr-neg97.6%
sqrt-prod97.6%
add-sqr-sqrt97.6%
div-inv97.6%
Applied egg-rr97.6%
associate-*r/97.6%
*-rgt-identity97.6%
Simplified97.6%
Final simplification95.9%
(FPCore (alphax alphay u0 cos2phi sin2phi)
:precision binary32
(if (<= sin2phi 400000.0)
(/
(* u0 (- 1.0 (* u0 (- (* u0 (- (* u0 -0.25) 0.3333333333333333)) 0.5))))
(+ (/ sin2phi (* alphay alphay)) (/ cos2phi (* alphax alphax))))
(/
(log1p (- u0))
(- (/ (/ cos2phi alphax) alphax) (/ (/ sin2phi alphay) alphay)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
float tmp;
if (sin2phi <= 400000.0f) {
tmp = (u0 * (1.0f - (u0 * ((u0 * ((u0 * -0.25f) - 0.3333333333333333f)) - 0.5f)))) / ((sin2phi / (alphay * alphay)) + (cos2phi / (alphax * alphax)));
} else {
tmp = log1pf(-u0) / (((cos2phi / alphax) / alphax) - ((sin2phi / alphay) / alphay));
}
return tmp;
}
function code(alphax, alphay, u0, cos2phi, sin2phi) tmp = Float32(0.0) if (sin2phi <= Float32(400000.0)) tmp = Float32(Float32(u0 * Float32(Float32(1.0) - Float32(u0 * Float32(Float32(u0 * Float32(Float32(u0 * Float32(-0.25)) - Float32(0.3333333333333333))) - Float32(0.5))))) / Float32(Float32(sin2phi / Float32(alphay * alphay)) + Float32(cos2phi / Float32(alphax * alphax)))); else tmp = Float32(log1p(Float32(-u0)) / Float32(Float32(Float32(cos2phi / alphax) / alphax) - Float32(Float32(sin2phi / alphay) / alphay))); end return tmp end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;sin2phi \leq 400000:\\
\;\;\;\;\frac{u0 \cdot \left(1 - u0 \cdot \left(u0 \cdot \left(u0 \cdot -0.25 - 0.3333333333333333\right) - 0.5\right)\right)}{\frac{sin2phi}{alphay \cdot alphay} + \frac{cos2phi}{alphax \cdot alphax}}\\
\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{log1p}\left(-u0\right)}{\frac{\frac{cos2phi}{alphax}}{alphax} - \frac{\frac{sin2phi}{alphay}}{alphay}}\\
\end{array}
\end{array}
if sin2phi < 4e5Initial program 54.0%
Taylor expanded in u0 around 0 94.4%
if 4e5 < sin2phi Initial program 67.1%
distribute-frac-neg67.1%
distribute-neg-frac267.1%
sub-neg67.1%
log1p-define97.6%
neg-sub097.6%
associate--r+97.6%
neg-sub097.6%
associate-/r*97.6%
distribute-neg-frac297.6%
Simplified97.6%
associate-/r*97.8%
div-inv97.7%
Applied egg-rr97.7%
associate-*r/97.8%
*-rgt-identity97.8%
Simplified97.8%
add-sqr-sqrt-0.0%
sqrt-unprod97.6%
sqr-neg97.6%
sqrt-prod97.6%
add-sqr-sqrt97.6%
div-inv97.6%
Applied egg-rr97.8%
associate-*r/97.6%
*-rgt-identity97.6%
Simplified97.8%
Final simplification95.9%
(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 59.9%
distribute-frac-neg59.9%
distribute-neg-frac259.9%
sub-neg59.9%
log1p-define98.1%
neg-sub098.1%
associate--r+98.1%
neg-sub098.1%
associate-/r*98.2%
distribute-neg-frac298.2%
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(log1p(Float32(-u0)) / Float32(Float32(Float32(cos2phi / alphax) / Float32(-alphax)) - Float32(Float32(sin2phi / alphay) / alphay))) end
\begin{array}{l}
\\
\frac{\mathsf{log1p}\left(-u0\right)}{\frac{\frac{cos2phi}{alphax}}{-alphax} - \frac{\frac{sin2phi}{alphay}}{alphay}}
\end{array}
Initial program 59.9%
distribute-frac-neg59.9%
distribute-neg-frac259.9%
sub-neg59.9%
log1p-define98.1%
neg-sub098.1%
associate--r+98.1%
neg-sub098.1%
associate-/r*98.2%
distribute-neg-frac298.2%
Simplified98.2%
associate-/r*98.2%
div-inv98.1%
Applied egg-rr98.1%
associate-*r/98.2%
*-rgt-identity98.2%
Simplified98.2%
Final simplification98.2%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (* u0 (- 1.0 (* u0 (- (* u0 (- (* u0 -0.25) 0.3333333333333333)) 0.5)))) (+ (/ sin2phi (* alphay alphay)) (/ cos2phi (* alphax alphax)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return (u0 * (1.0f - (u0 * ((u0 * ((u0 * -0.25f) - 0.3333333333333333f)) - 0.5f)))) / ((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 * (1.0e0 - (u0 * ((u0 * ((u0 * (-0.25e0)) - 0.3333333333333333e0)) - 0.5e0)))) / ((sin2phi / (alphay * alphay)) + (cos2phi / (alphax * alphax)))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(u0 * Float32(Float32(1.0) - Float32(u0 * Float32(Float32(u0 * Float32(Float32(u0 * Float32(-0.25)) - Float32(0.3333333333333333))) - Float32(0.5))))) / Float32(Float32(sin2phi / Float32(alphay * alphay)) + Float32(cos2phi / Float32(alphax * alphax)))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = (u0 * (single(1.0) - (u0 * ((u0 * ((u0 * single(-0.25)) - single(0.3333333333333333))) - single(0.5))))) / ((sin2phi / (alphay * alphay)) + (cos2phi / (alphax * alphax))); end
\begin{array}{l}
\\
\frac{u0 \cdot \left(1 - u0 \cdot \left(u0 \cdot \left(u0 \cdot -0.25 - 0.3333333333333333\right) - 0.5\right)\right)}{\frac{sin2phi}{alphay \cdot alphay} + \frac{cos2phi}{alphax \cdot alphax}}
\end{array}
Initial program 59.9%
Taylor expanded in u0 around 0 92.5%
Final simplification92.5%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (* u0 (+ 1.0 (* u0 (- 0.5 (* u0 -0.3333333333333333))))) (+ (/ sin2phi (* alphay alphay)) (/ cos2phi (* alphax alphax)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return (u0 * (1.0f + (u0 * (0.5f - (u0 * -0.3333333333333333f))))) / ((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 * (1.0e0 + (u0 * (0.5e0 - (u0 * (-0.3333333333333333e0)))))) / ((sin2phi / (alphay * alphay)) + (cos2phi / (alphax * alphax)))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(u0 * Float32(Float32(1.0) + Float32(u0 * Float32(Float32(0.5) - Float32(u0 * Float32(-0.3333333333333333)))))) / Float32(Float32(sin2phi / Float32(alphay * alphay)) + Float32(cos2phi / Float32(alphax * alphax)))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = (u0 * (single(1.0) + (u0 * (single(0.5) - (u0 * single(-0.3333333333333333)))))) / ((sin2phi / (alphay * alphay)) + (cos2phi / (alphax * alphax))); end
\begin{array}{l}
\\
\frac{u0 \cdot \left(1 + u0 \cdot \left(0.5 - u0 \cdot -0.3333333333333333\right)\right)}{\frac{sin2phi}{alphay \cdot alphay} + \frac{cos2phi}{alphax \cdot alphax}}
\end{array}
Initial program 59.9%
Taylor expanded in u0 around 0 90.9%
Final simplification90.9%
(FPCore (alphax alphay u0 cos2phi sin2phi) :precision binary32 (/ (* u0 (- 1.0 (* u0 -0.5))) (+ (/ sin2phi (* alphay alphay)) (/ cos2phi (* alphax alphax)))))
float code(float alphax, float alphay, float u0, float cos2phi, float sin2phi) {
return (u0 * (1.0f - (u0 * -0.5f))) / ((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 * (1.0e0 - (u0 * (-0.5e0)))) / ((sin2phi / (alphay * alphay)) + (cos2phi / (alphax * alphax)))
end function
function code(alphax, alphay, u0, cos2phi, sin2phi) return Float32(Float32(u0 * Float32(Float32(1.0) - Float32(u0 * Float32(-0.5)))) / Float32(Float32(sin2phi / Float32(alphay * alphay)) + Float32(cos2phi / Float32(alphax * alphax)))) end
function tmp = code(alphax, alphay, u0, cos2phi, sin2phi) tmp = (u0 * (single(1.0) - (u0 * single(-0.5)))) / ((sin2phi / (alphay * alphay)) + (cos2phi / (alphax * alphax))); end
\begin{array}{l}
\\
\frac{u0 \cdot \left(1 - u0 \cdot -0.5\right)}{\frac{sin2phi}{alphay \cdot alphay} + \frac{cos2phi}{alphax \cdot alphax}}
\end{array}
Initial program 59.9%
Taylor expanded in u0 around 0 88.1%
Final simplification88.1%
(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 59.9%
Taylor expanded in u0 around 0 76.9%
mul-1-neg76.9%
Simplified76.9%
Final simplification76.9%
herbie shell --seed 2024080
(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)))))