
(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 8 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) 0.9860000014305115)
(*
(log (- 1.0 u0))
(*
(/ (* (* alpha alpha) alpha) (* (- alpha) alpha))
(/ (pow alpha 3.0) (* alpha alpha))))
(*
(* (- (* (+ 0.5 (* 0.3333333333333333 u0)) u0) -1.0) (* alpha alpha))
u0)))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.9860000014305115f) {
tmp = logf((1.0f - u0)) * ((((alpha * alpha) * alpha) / (-alpha * alpha)) * (powf(alpha, 3.0f) / (alpha * alpha)));
} else {
tmp = ((((0.5f + (0.3333333333333333f * u0)) * u0) - -1.0f) * (alpha * alpha)) * u0;
}
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) <= 0.9860000014305115e0) then
tmp = log((1.0e0 - u0)) * ((((alpha * alpha) * alpha) / (-alpha * alpha)) * ((alpha ** 3.0e0) / (alpha * alpha)))
else
tmp = ((((0.5e0 + (0.3333333333333333e0 * u0)) * u0) - (-1.0e0)) * (alpha * alpha)) * u0
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.9860000014305115)) tmp = Float32(log(Float32(Float32(1.0) - u0)) * Float32(Float32(Float32(Float32(alpha * alpha) * alpha) / Float32(Float32(-alpha) * alpha)) * Float32((alpha ^ Float32(3.0)) / Float32(alpha * alpha)))); else tmp = Float32(Float32(Float32(Float32(Float32(Float32(0.5) + Float32(Float32(0.3333333333333333) * u0)) * u0) - Float32(-1.0)) * Float32(alpha * alpha)) * u0); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if ((single(1.0) - u0) <= single(0.9860000014305115)) tmp = log((single(1.0) - u0)) * ((((alpha * alpha) * alpha) / (-alpha * alpha)) * ((alpha ^ single(3.0)) / (alpha * alpha))); else tmp = ((((single(0.5) + (single(0.3333333333333333) * u0)) * u0) - single(-1.0)) * (alpha * alpha)) * u0; end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.9860000014305115:\\
\;\;\;\;\log \left(1 - u0\right) \cdot \left(\frac{\left(\alpha \cdot \alpha\right) \cdot \alpha}{\left(-\alpha\right) \cdot \alpha} \cdot \frac{{\alpha}^{3}}{\alpha \cdot \alpha}\right)\\
\mathbf{else}:\\
\;\;\;\;\left(\left(\left(0.5 + 0.3333333333333333 \cdot u0\right) \cdot u0 - -1\right) \cdot \left(\alpha \cdot \alpha\right)\right) \cdot u0\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.986000001Initial program 94.5%
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
div-invN/A
lower-*.f32N/A
+-lft-identityN/A
lower-/.f3294.4
Applied rewrites94.4%
Applied rewrites94.5%
lift-pow.f32N/A
lift-neg.f32N/A
cube-negN/A
unpow3N/A
lift-*.f32N/A
distribute-rgt-neg-inN/A
neg-mul-1N/A
metadata-evalN/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
metadata-eval94.6
Applied rewrites94.6%
if 0.986000001 < (-.f32 #s(literal 1 binary32) u0) Initial program 44.7%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
Applied rewrites82.7%
Applied rewrites95.3%
Applied rewrites98.5%
Final simplification97.8%
(FPCore (alpha u0)
:precision binary32
(if (<= (- 1.0 u0) 0.9829999804496765)
(* (/ (* (pow (- alpha) 3.0) alpha) (* alpha alpha)) (log (- 1.0 u0)))
(*
(* (- (* (+ 0.5 (* 0.3333333333333333 u0)) u0) -1.0) (* alpha alpha))
u0)))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.9829999804496765f) {
tmp = ((powf(-alpha, 3.0f) * alpha) / (alpha * alpha)) * logf((1.0f - u0));
} else {
tmp = ((((0.5f + (0.3333333333333333f * u0)) * u0) - -1.0f) * (alpha * alpha)) * u0;
}
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) <= 0.9829999804496765e0) then
tmp = (((-alpha ** 3.0e0) * alpha) / (alpha * alpha)) * log((1.0e0 - u0))
else
tmp = ((((0.5e0 + (0.3333333333333333e0 * u0)) * u0) - (-1.0e0)) * (alpha * alpha)) * u0
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.9829999804496765)) tmp = Float32(Float32(Float32((Float32(-alpha) ^ Float32(3.0)) * alpha) / Float32(alpha * alpha)) * log(Float32(Float32(1.0) - u0))); else tmp = Float32(Float32(Float32(Float32(Float32(Float32(0.5) + Float32(Float32(0.3333333333333333) * u0)) * u0) - Float32(-1.0)) * Float32(alpha * alpha)) * u0); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if ((single(1.0) - u0) <= single(0.9829999804496765)) tmp = (((-alpha ^ single(3.0)) * alpha) / (alpha * alpha)) * log((single(1.0) - u0)); else tmp = ((((single(0.5) + (single(0.3333333333333333) * u0)) * u0) - single(-1.0)) * (alpha * alpha)) * u0; end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.9829999804496765:\\
\;\;\;\;\frac{{\left(-\alpha\right)}^{3} \cdot \alpha}{\alpha \cdot \alpha} \cdot \log \left(1 - u0\right)\\
\mathbf{else}:\\
\;\;\;\;\left(\left(\left(0.5 + 0.3333333333333333 \cdot u0\right) \cdot u0 - -1\right) \cdot \left(\alpha \cdot \alpha\right)\right) \cdot u0\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.98299998Initial program 94.9%
lift-*.f32N/A
lift-neg.f32N/A
neg-sub0N/A
flip3--N/A
associate-*l/N/A
metadata-evalN/A
+-lft-identityN/A
mul0-lftN/A
+-rgt-identityN/A
lower-/.f32N/A
lower-*.f32N/A
metadata-evalN/A
sub0-negN/A
cube-negN/A
lift-neg.f32N/A
lower-pow.f32N/A
lower-*.f3295.0
Applied rewrites95.0%
if 0.98299998 < (-.f32 #s(literal 1 binary32) u0) Initial program 45.3%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
Applied rewrites82.2%
Applied rewrites94.9%
Applied rewrites98.4%
Final simplification97.8%
(FPCore (alpha u0)
:precision binary32
(if (<= (- 1.0 u0) 0.9829999804496765)
(*
(/ (* (* (- alpha) alpha) (* alpha alpha)) (* alpha alpha))
(log (- 1.0 u0)))
(*
(* (- (* (+ 0.5 (* 0.3333333333333333 u0)) u0) -1.0) (* alpha alpha))
u0)))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.9829999804496765f) {
tmp = (((-alpha * alpha) * (alpha * alpha)) / (alpha * alpha)) * logf((1.0f - u0));
} else {
tmp = ((((0.5f + (0.3333333333333333f * u0)) * u0) - -1.0f) * (alpha * alpha)) * u0;
}
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) <= 0.9829999804496765e0) then
tmp = (((-alpha * alpha) * (alpha * alpha)) / (alpha * alpha)) * log((1.0e0 - u0))
else
tmp = ((((0.5e0 + (0.3333333333333333e0 * u0)) * u0) - (-1.0e0)) * (alpha * alpha)) * u0
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.9829999804496765)) tmp = Float32(Float32(Float32(Float32(Float32(-alpha) * alpha) * Float32(alpha * alpha)) / Float32(alpha * alpha)) * log(Float32(Float32(1.0) - u0))); else tmp = Float32(Float32(Float32(Float32(Float32(Float32(0.5) + Float32(Float32(0.3333333333333333) * u0)) * u0) - Float32(-1.0)) * Float32(alpha * alpha)) * u0); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if ((single(1.0) - u0) <= single(0.9829999804496765)) tmp = (((-alpha * alpha) * (alpha * alpha)) / (alpha * alpha)) * log((single(1.0) - u0)); else tmp = ((((single(0.5) + (single(0.3333333333333333) * u0)) * u0) - single(-1.0)) * (alpha * alpha)) * u0; end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.9829999804496765:\\
\;\;\;\;\frac{\left(\left(-\alpha\right) \cdot \alpha\right) \cdot \left(\alpha \cdot \alpha\right)}{\alpha \cdot \alpha} \cdot \log \left(1 - u0\right)\\
\mathbf{else}:\\
\;\;\;\;\left(\left(\left(0.5 + 0.3333333333333333 \cdot u0\right) \cdot u0 - -1\right) \cdot \left(\alpha \cdot \alpha\right)\right) \cdot u0\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.98299998Initial program 94.9%
+-lft-identityN/A
flip-+N/A
neg-sub0N/A
lift-*.f32N/A
lift-neg.f32N/A
distribute-lft-neg-outN/A
remove-double-negN/A
lower-/.f32N/A
metadata-evalN/A
lower--.f32N/A
lower-*.f32N/A
lower-*.f3295.0
Applied rewrites95.0%
if 0.98299998 < (-.f32 #s(literal 1 binary32) u0) Initial program 45.3%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
Applied rewrites82.2%
Applied rewrites94.9%
Applied rewrites98.4%
Final simplification97.8%
(FPCore (alpha u0)
:precision binary32
(if (<= (- 1.0 u0) 0.9860000014305115)
(* (log (- 1.0 u0)) (* (- alpha) alpha))
(*
(* (- (* (+ 0.5 (* 0.3333333333333333 u0)) u0) -1.0) (* alpha alpha))
u0)))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.9860000014305115f) {
tmp = logf((1.0f - u0)) * (-alpha * alpha);
} else {
tmp = ((((0.5f + (0.3333333333333333f * u0)) * u0) - -1.0f) * (alpha * alpha)) * u0;
}
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) <= 0.9860000014305115e0) then
tmp = log((1.0e0 - u0)) * (-alpha * alpha)
else
tmp = ((((0.5e0 + (0.3333333333333333e0 * u0)) * u0) - (-1.0e0)) * (alpha * alpha)) * u0
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.9860000014305115)) tmp = Float32(log(Float32(Float32(1.0) - u0)) * Float32(Float32(-alpha) * alpha)); else tmp = Float32(Float32(Float32(Float32(Float32(Float32(0.5) + Float32(Float32(0.3333333333333333) * u0)) * u0) - Float32(-1.0)) * Float32(alpha * alpha)) * u0); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if ((single(1.0) - u0) <= single(0.9860000014305115)) tmp = log((single(1.0) - u0)) * (-alpha * alpha); else tmp = ((((single(0.5) + (single(0.3333333333333333) * u0)) * u0) - single(-1.0)) * (alpha * alpha)) * u0; end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.9860000014305115:\\
\;\;\;\;\log \left(1 - u0\right) \cdot \left(\left(-\alpha\right) \cdot \alpha\right)\\
\mathbf{else}:\\
\;\;\;\;\left(\left(\left(0.5 + 0.3333333333333333 \cdot u0\right) \cdot u0 - -1\right) \cdot \left(\alpha \cdot \alpha\right)\right) \cdot u0\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.986000001Initial program 94.5%
if 0.986000001 < (-.f32 #s(literal 1 binary32) u0) Initial program 44.7%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
Applied rewrites82.7%
Applied rewrites95.3%
Applied rewrites98.5%
Final simplification97.8%
(FPCore (alpha u0) :precision binary32 (* (* (+ (/ -1.0 (- (* (* 0.3333333333333333 u0) u0) 1.0)) (* 0.5 u0)) (* alpha alpha)) u0))
float code(float alpha, float u0) {
return (((-1.0f / (((0.3333333333333333f * u0) * u0) - 1.0f)) + (0.5f * u0)) * (alpha * alpha)) * u0;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = ((((-1.0e0) / (((0.3333333333333333e0 * u0) * u0) - 1.0e0)) + (0.5e0 * u0)) * (alpha * alpha)) * u0
end function
function code(alpha, u0) return Float32(Float32(Float32(Float32(Float32(-1.0) / Float32(Float32(Float32(Float32(0.3333333333333333) * u0) * u0) - Float32(1.0))) + Float32(Float32(0.5) * u0)) * Float32(alpha * alpha)) * u0) end
function tmp = code(alpha, u0) tmp = (((single(-1.0) / (((single(0.3333333333333333) * u0) * u0) - single(1.0))) + (single(0.5) * u0)) * (alpha * alpha)) * u0; end
\begin{array}{l}
\\
\left(\left(\frac{-1}{\left(0.3333333333333333 \cdot u0\right) \cdot u0 - 1} + 0.5 \cdot u0\right) \cdot \left(\alpha \cdot \alpha\right)\right) \cdot u0
\end{array}
Initial program 53.8%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
Applied rewrites74.8%
Applied rewrites92.1%
Applied rewrites92.1%
Taylor expanded in u0 around 0
Applied rewrites92.2%
Final simplification92.2%
(FPCore (alpha u0) :precision binary32 (* (* (- (* (+ 0.5 (* 0.3333333333333333 u0)) u0) -1.0) (* alpha alpha)) u0))
float code(float alpha, float u0) {
return ((((0.5f + (0.3333333333333333f * u0)) * u0) - -1.0f) * (alpha * alpha)) * u0;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = ((((0.5e0 + (0.3333333333333333e0 * u0)) * u0) - (-1.0e0)) * (alpha * alpha)) * u0
end function
function code(alpha, u0) return Float32(Float32(Float32(Float32(Float32(Float32(0.5) + Float32(Float32(0.3333333333333333) * u0)) * u0) - Float32(-1.0)) * Float32(alpha * alpha)) * u0) end
function tmp = code(alpha, u0) tmp = ((((single(0.5) + (single(0.3333333333333333) * u0)) * u0) - single(-1.0)) * (alpha * alpha)) * u0; end
\begin{array}{l}
\\
\left(\left(\left(0.5 + 0.3333333333333333 \cdot u0\right) \cdot u0 - -1\right) \cdot \left(\alpha \cdot \alpha\right)\right) \cdot u0
\end{array}
Initial program 53.8%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
Applied rewrites74.8%
Applied rewrites87.4%
Applied rewrites92.2%
Final simplification92.2%
(FPCore (alpha u0) :precision binary32 (* (* (- (* 0.5 u0) -1.0) (* alpha alpha)) u0))
float code(float alpha, float u0) {
return (((0.5f * u0) - -1.0f) * (alpha * alpha)) * u0;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (((0.5e0 * u0) - (-1.0e0)) * (alpha * alpha)) * u0
end function
function code(alpha, u0) return Float32(Float32(Float32(Float32(Float32(0.5) * u0) - Float32(-1.0)) * Float32(alpha * alpha)) * u0) end
function tmp = code(alpha, u0) tmp = (((single(0.5) * u0) - single(-1.0)) * (alpha * alpha)) * u0; end
\begin{array}{l}
\\
\left(\left(0.5 \cdot u0 - -1\right) \cdot \left(\alpha \cdot \alpha\right)\right) \cdot u0
\end{array}
Initial program 53.8%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
Applied rewrites74.8%
Applied rewrites87.4%
Taylor expanded in u0 around 0
Applied rewrites87.7%
Final simplification87.7%
(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 53.8%
Taylor expanded in u0 around 0
lower-*.f32N/A
unpow2N/A
lower-*.f3275.5
Applied rewrites75.5%
herbie shell --seed 2024296
(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))))