
(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 7 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
(if (<= (- 1.0 u0) 0.9639599919319153)
(* (log (- 1.0 u0)) (/ (pow alpha 3.0) (- alpha)))
(*
(*
(*
(* u0 u0)
(*
(- (/ (- -0.3333333333333333 (/ (- (/ 1.0 u0) -0.5) u0)) u0) 0.25)
u0))
u0)
(* (- alpha) alpha))))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.9639599919319153f) {
tmp = logf((1.0f - u0)) * (powf(alpha, 3.0f) / -alpha);
} else {
tmp = (((u0 * u0) * ((((-0.3333333333333333f - (((1.0f / u0) - -0.5f) / u0)) / u0) - 0.25f) * u0)) * u0) * (-alpha * alpha);
}
return tmp;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
real(4) :: tmp
if ((1.0e0 - u0) <= 0.9639599919319153e0) then
tmp = log((1.0e0 - u0)) * ((alpha ** 3.0e0) / -alpha)
else
tmp = (((u0 * u0) * (((((-0.3333333333333333e0) - (((1.0e0 / u0) - (-0.5e0)) / u0)) / u0) - 0.25e0) * u0)) * u0) * (-alpha * alpha)
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.9639599919319153)) tmp = Float32(log(Float32(Float32(1.0) - u0)) * Float32((alpha ^ Float32(3.0)) / Float32(-alpha))); else tmp = Float32(Float32(Float32(Float32(u0 * u0) * Float32(Float32(Float32(Float32(Float32(-0.3333333333333333) - Float32(Float32(Float32(Float32(1.0) / u0) - Float32(-0.5)) / u0)) / u0) - Float32(0.25)) * u0)) * u0) * Float32(Float32(-alpha) * alpha)); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if ((single(1.0) - u0) <= single(0.9639599919319153)) tmp = log((single(1.0) - u0)) * ((alpha ^ single(3.0)) / -alpha); else tmp = (((u0 * u0) * ((((single(-0.3333333333333333) - (((single(1.0) / u0) - single(-0.5)) / u0)) / u0) - single(0.25)) * u0)) * u0) * (-alpha * alpha); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.9639599919319153:\\
\;\;\;\;\log \left(1 - u0\right) \cdot \frac{{\alpha}^{3}}{-\alpha}\\
\mathbf{else}:\\
\;\;\;\;\left(\left(\left(u0 \cdot u0\right) \cdot \left(\left(\frac{-0.3333333333333333 - \frac{\frac{1}{u0} - -0.5}{u0}}{u0} - 0.25\right) \cdot u0\right)\right) \cdot u0\right) \cdot \left(\left(-\alpha\right) \cdot \alpha\right)\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.963959992Initial program 96.9%
lift-*.f32N/A
lift-neg.f32N/A
neg-sub0N/A
flip--N/A
metadata-evalN/A
neg-sub0N/A
distribute-lft-neg-outN/A
lift-neg.f32N/A
lift-*.f32N/A
+-lft-identityN/A
associate-*l/N/A
clear-numN/A
lower-/.f32N/A
lower-/.f32N/A
lower-*.f3296.5
Applied rewrites96.5%
lift-/.f32N/A
lift-/.f32N/A
clear-numN/A
frac-2negN/A
lift-*.f32N/A
distribute-lft-neg-inN/A
lift-*.f32N/A
lift-neg.f32N/A
distribute-lft-neg-outN/A
lift-*.f32N/A
remove-double-negN/A
lift-*.f32N/A
unpow3N/A
lift-pow.f32N/A
lift-neg.f32N/A
lower-/.f3297.1
Applied rewrites97.1%
if 0.963959992 < (-.f32 #s(literal 1 binary32) u0) Initial program 50.3%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f32N/A
sub-negN/A
metadata-evalN/A
lower-fma.f3280.2
Applied rewrites80.2%
Taylor expanded in u0 around inf
Applied rewrites98.1%
Applied rewrites98.3%
Final simplification98.1%
(FPCore (alpha u0)
:precision binary32
(let* ((t_0 (* (- alpha) alpha)))
(if (<= (- 1.0 u0) 0.9639599919319153)
(* t_0 (log (- 1.0 u0)))
(*
(*
(*
(* u0 u0)
(*
(- (/ (- -0.3333333333333333 (/ (- (/ 1.0 u0) -0.5) u0)) u0) 0.25)
u0))
u0)
t_0))))
float code(float alpha, float u0) {
float t_0 = -alpha * alpha;
float tmp;
if ((1.0f - u0) <= 0.9639599919319153f) {
tmp = t_0 * logf((1.0f - u0));
} else {
tmp = (((u0 * u0) * ((((-0.3333333333333333f - (((1.0f / u0) - -0.5f) / u0)) / u0) - 0.25f) * u0)) * u0) * t_0;
}
return tmp;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
real(4) :: t_0
real(4) :: tmp
t_0 = -alpha * alpha
if ((1.0e0 - u0) <= 0.9639599919319153e0) then
tmp = t_0 * log((1.0e0 - u0))
else
tmp = (((u0 * u0) * (((((-0.3333333333333333e0) - (((1.0e0 / u0) - (-0.5e0)) / u0)) / u0) - 0.25e0) * u0)) * u0) * t_0
end if
code = tmp
end function
function code(alpha, u0) t_0 = Float32(Float32(-alpha) * alpha) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.9639599919319153)) tmp = Float32(t_0 * log(Float32(Float32(1.0) - u0))); else tmp = Float32(Float32(Float32(Float32(u0 * u0) * Float32(Float32(Float32(Float32(Float32(-0.3333333333333333) - Float32(Float32(Float32(Float32(1.0) / u0) - Float32(-0.5)) / u0)) / u0) - Float32(0.25)) * u0)) * u0) * t_0); end return tmp end
function tmp_2 = code(alpha, u0) t_0 = -alpha * alpha; tmp = single(0.0); if ((single(1.0) - u0) <= single(0.9639599919319153)) tmp = t_0 * log((single(1.0) - u0)); else tmp = (((u0 * u0) * ((((single(-0.3333333333333333) - (((single(1.0) / u0) - single(-0.5)) / u0)) / u0) - single(0.25)) * u0)) * u0) * t_0; end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(-\alpha\right) \cdot \alpha\\
\mathbf{if}\;1 - u0 \leq 0.9639599919319153:\\
\;\;\;\;t\_0 \cdot \log \left(1 - u0\right)\\
\mathbf{else}:\\
\;\;\;\;\left(\left(\left(u0 \cdot u0\right) \cdot \left(\left(\frac{-0.3333333333333333 - \frac{\frac{1}{u0} - -0.5}{u0}}{u0} - 0.25\right) \cdot u0\right)\right) \cdot u0\right) \cdot t\_0\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.963959992Initial program 96.9%
if 0.963959992 < (-.f32 #s(literal 1 binary32) u0) Initial program 50.3%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f32N/A
sub-negN/A
metadata-evalN/A
lower-fma.f3280.2
Applied rewrites79.8%
Taylor expanded in u0 around inf
Applied rewrites98.1%
Applied rewrites98.3%
Final simplification98.1%
(FPCore (alpha u0)
:precision binary32
(*
(*
(*
(* u0 u0)
(* (- (/ (- -0.3333333333333333 (/ (- (/ 1.0 u0) -0.5) u0)) u0) 0.25) u0))
u0)
(* (- alpha) alpha)))
float code(float alpha, float u0) {
return (((u0 * u0) * ((((-0.3333333333333333f - (((1.0f / u0) - -0.5f) / u0)) / u0) - 0.25f) * u0)) * u0) * (-alpha * alpha);
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (((u0 * u0) * (((((-0.3333333333333333e0) - (((1.0e0 / u0) - (-0.5e0)) / u0)) / u0) - 0.25e0) * u0)) * u0) * (-alpha * alpha)
end function
function code(alpha, u0) return Float32(Float32(Float32(Float32(u0 * u0) * Float32(Float32(Float32(Float32(Float32(-0.3333333333333333) - Float32(Float32(Float32(Float32(1.0) / u0) - Float32(-0.5)) / u0)) / u0) - Float32(0.25)) * u0)) * u0) * Float32(Float32(-alpha) * alpha)) end
function tmp = code(alpha, u0) tmp = (((u0 * u0) * ((((single(-0.3333333333333333) - (((single(1.0) / u0) - single(-0.5)) / u0)) / u0) - single(0.25)) * u0)) * u0) * (-alpha * alpha); end
\begin{array}{l}
\\
\left(\left(\left(u0 \cdot u0\right) \cdot \left(\left(\frac{-0.3333333333333333 - \frac{\frac{1}{u0} - -0.5}{u0}}{u0} - 0.25\right) \cdot u0\right)\right) \cdot u0\right) \cdot \left(\left(-\alpha\right) \cdot \alpha\right)
\end{array}
Initial program 57.4%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f32N/A
sub-negN/A
metadata-evalN/A
lower-fma.f3273.5
Applied rewrites73.1%
Taylor expanded in u0 around inf
Applied rewrites92.5%
Applied rewrites92.7%
Final simplification92.7%
(FPCore (alpha u0)
:precision binary32
(*
(*
(*
(*
(* (- (/ (- -0.3333333333333333 (/ (- (/ 1.0 u0) -0.5) u0)) u0) 0.25) u0)
u0)
u0)
u0)
(* (- alpha) alpha)))
float code(float alpha, float u0) {
return (((((((-0.3333333333333333f - (((1.0f / u0) - -0.5f) / u0)) / u0) - 0.25f) * u0) * u0) * u0) * u0) * (-alpha * alpha);
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = ((((((((-0.3333333333333333e0) - (((1.0e0 / u0) - (-0.5e0)) / u0)) / u0) - 0.25e0) * u0) * u0) * u0) * u0) * (-alpha * alpha)
end function
function code(alpha, u0) return Float32(Float32(Float32(Float32(Float32(Float32(Float32(Float32(Float32(-0.3333333333333333) - Float32(Float32(Float32(Float32(1.0) / u0) - Float32(-0.5)) / u0)) / u0) - Float32(0.25)) * u0) * u0) * u0) * u0) * Float32(Float32(-alpha) * alpha)) end
function tmp = code(alpha, u0) tmp = (((((((single(-0.3333333333333333) - (((single(1.0) / u0) - single(-0.5)) / u0)) / u0) - single(0.25)) * u0) * u0) * u0) * u0) * (-alpha * alpha); end
\begin{array}{l}
\\
\left(\left(\left(\left(\left(\frac{-0.3333333333333333 - \frac{\frac{1}{u0} - -0.5}{u0}}{u0} - 0.25\right) \cdot u0\right) \cdot u0\right) \cdot u0\right) \cdot u0\right) \cdot \left(\left(-\alpha\right) \cdot \alpha\right)
\end{array}
Initial program 57.4%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f32N/A
sub-negN/A
metadata-evalN/A
lower-fma.f3273.5
Applied rewrites73.1%
Taylor expanded in u0 around inf
Applied rewrites92.5%
Applied rewrites92.7%
Applied rewrites92.7%
Final simplification92.7%
(FPCore (alpha u0) :precision binary32 (* (* (+ (* (+ (* (fma -0.25 u0 -0.3333333333333333) u0) -0.5) u0) -1.0) u0) (* (- alpha) alpha)))
float code(float alpha, float u0) {
return (((((fmaf(-0.25f, u0, -0.3333333333333333f) * u0) + -0.5f) * u0) + -1.0f) * u0) * (-alpha * alpha);
}
function code(alpha, u0) return Float32(Float32(Float32(Float32(Float32(Float32(fma(Float32(-0.25), u0, Float32(-0.3333333333333333)) * u0) + Float32(-0.5)) * u0) + Float32(-1.0)) * u0) * Float32(Float32(-alpha) * alpha)) end
\begin{array}{l}
\\
\left(\left(\left(\mathsf{fma}\left(-0.25, u0, -0.3333333333333333\right) \cdot u0 + -0.5\right) \cdot u0 + -1\right) \cdot u0\right) \cdot \left(\left(-\alpha\right) \cdot \alpha\right)
\end{array}
Initial program 57.4%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f32N/A
sub-negN/A
metadata-evalN/A
lower-fma.f3273.5
Applied rewrites73.1%
Applied rewrites86.2%
Applied rewrites91.1%
Final simplification91.1%
(FPCore (alpha u0) :precision binary32 (* (* (+ (* -0.5 u0) -1.0) u0) (* (- alpha) alpha)))
float code(float alpha, float u0) {
return (((-0.5f * u0) + -1.0f) * u0) * (-alpha * alpha);
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = ((((-0.5e0) * u0) + (-1.0e0)) * u0) * (-alpha * alpha)
end function
function code(alpha, u0) return Float32(Float32(Float32(Float32(Float32(-0.5) * u0) + Float32(-1.0)) * u0) * Float32(Float32(-alpha) * alpha)) end
function tmp = code(alpha, u0) tmp = (((single(-0.5) * u0) + single(-1.0)) * u0) * (-alpha * alpha); end
\begin{array}{l}
\\
\left(\left(-0.5 \cdot u0 + -1\right) \cdot u0\right) \cdot \left(\left(-\alpha\right) \cdot \alpha\right)
\end{array}
Initial program 57.4%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f32N/A
sub-negN/A
*-commutativeN/A
metadata-evalN/A
lower-fma.f32N/A
sub-negN/A
metadata-evalN/A
lower-fma.f3273.5
Applied rewrites73.1%
Applied rewrites86.2%
Taylor expanded in u0 around 0
Applied rewrites86.4%
Final simplification86.4%
(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 57.4%
Taylor expanded in u0 around 0
lower-*.f32N/A
unpow2N/A
lower-*.f3273.5
Applied rewrites73.5%
herbie shell --seed 2024295
(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))))