
(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
(let* ((t_0 (* (- alpha) alpha)))
(if (<= (- 1.0 u0) 0.9599999785423279)
(* t_0 (log (- 1.0 u0)))
(*
t_0
(*
(- (* (- (* (- (* -0.25 u0) 0.3333333333333333) u0) 0.5) u0) 1.0)
u0)))))
float code(float alpha, float u0) {
float t_0 = -alpha * alpha;
float tmp;
if ((1.0f - u0) <= 0.9599999785423279f) {
tmp = t_0 * logf((1.0f - u0));
} else {
tmp = t_0 * (((((((-0.25f * u0) - 0.3333333333333333f) * u0) - 0.5f) * u0) - 1.0f) * u0);
}
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) <= 0.9599999785423279e0) then
tmp = t_0 * log((1.0e0 - u0))
else
tmp = t_0 * ((((((((-0.25e0) * u0) - 0.3333333333333333e0) * u0) - 0.5e0) * u0) - 1.0e0) * u0)
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(0.9599999785423279)) tmp = Float32(t_0 * log(Float32(Float32(1.0) - u0))); else tmp = Float32(t_0 * Float32(Float32(Float32(Float32(Float32(Float32(Float32(Float32(-0.25) * u0) - Float32(0.3333333333333333)) * u0) - Float32(0.5)) * u0) - Float32(1.0)) * u0)); end return tmp end
function tmp_2 = code(alpha, u0) t_0 = -alpha * alpha; tmp = single(0.0); if ((single(1.0) - u0) <= single(0.9599999785423279)) tmp = t_0 * log((single(1.0) - u0)); else tmp = t_0 * (((((((single(-0.25) * u0) - single(0.3333333333333333)) * u0) - single(0.5)) * u0) - single(1.0)) * u0); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \left(-\alpha\right) \cdot \alpha\\
\mathbf{if}\;1 - u0 \leq 0.9599999785423279:\\
\;\;\;\;t\_0 \cdot \log \left(1 - u0\right)\\
\mathbf{else}:\\
\;\;\;\;t\_0 \cdot \left(\left(\left(\left(-0.25 \cdot u0 - 0.3333333333333333\right) \cdot u0 - 0.5\right) \cdot u0 - 1\right) \cdot u0\right)\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.959999979Initial program 97.2%
if 0.959999979 < (-.f32 #s(literal 1 binary32) u0) Initial program 49.1%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
metadata-evalN/A
distribute-lft-neg-inN/A
lower--.f32N/A
distribute-lft-neg-inN/A
metadata-evalN/A
lower-*.f3298.6
Applied rewrites98.6%
(FPCore (alpha u0)
:precision binary32
(if (<= (- 1.0 u0) 0.9599999785423279)
(* (* (log (- 1.0 u0)) (- alpha)) alpha)
(*
(* (- alpha) alpha)
(* (- (* (- (* (- (* -0.25 u0) 0.3333333333333333) u0) 0.5) u0) 1.0) u0))))
float code(float alpha, float u0) {
float tmp;
if ((1.0f - u0) <= 0.9599999785423279f) {
tmp = (logf((1.0f - u0)) * -alpha) * alpha;
} else {
tmp = (-alpha * alpha) * (((((((-0.25f * u0) - 0.3333333333333333f) * u0) - 0.5f) * u0) - 1.0f) * 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) <= 0.9599999785423279e0) then
tmp = (log((1.0e0 - u0)) * -alpha) * alpha
else
tmp = (-alpha * alpha) * ((((((((-0.25e0) * u0) - 0.3333333333333333e0) * u0) - 0.5e0) * u0) - 1.0e0) * u0)
end if
code = tmp
end function
function code(alpha, u0) tmp = Float32(0.0) if (Float32(Float32(1.0) - u0) <= Float32(0.9599999785423279)) tmp = Float32(Float32(log(Float32(Float32(1.0) - u0)) * Float32(-alpha)) * alpha); else tmp = Float32(Float32(Float32(-alpha) * alpha) * Float32(Float32(Float32(Float32(Float32(Float32(Float32(Float32(-0.25) * u0) - Float32(0.3333333333333333)) * u0) - Float32(0.5)) * u0) - Float32(1.0)) * u0)); end return tmp end
function tmp_2 = code(alpha, u0) tmp = single(0.0); if ((single(1.0) - u0) <= single(0.9599999785423279)) tmp = (log((single(1.0) - u0)) * -alpha) * alpha; else tmp = (-alpha * alpha) * (((((((single(-0.25) * u0) - single(0.3333333333333333)) * u0) - single(0.5)) * u0) - single(1.0)) * u0); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;1 - u0 \leq 0.9599999785423279:\\
\;\;\;\;\left(\log \left(1 - u0\right) \cdot \left(-\alpha\right)\right) \cdot \alpha\\
\mathbf{else}:\\
\;\;\;\;\left(\left(-\alpha\right) \cdot \alpha\right) \cdot \left(\left(\left(\left(-0.25 \cdot u0 - 0.3333333333333333\right) \cdot u0 - 0.5\right) \cdot u0 - 1\right) \cdot u0\right)\\
\end{array}
\end{array}
if (-.f32 #s(literal 1 binary32) u0) < 0.959999979Initial program 97.2%
lift-*.f32N/A
lift-log.f32N/A
log-pow-revN/A
sqr-powN/A
pow-prod-downN/A
log-powN/A
lower-*.f32N/A
frac-2negN/A
lift-*.f32N/A
distribute-rgt-neg-outN/A
lift-neg.f32N/A
sqr-neg-revN/A
lower-/.f32N/A
lower-*.f32N/A
metadata-evalN/A
lower-log.f32N/A
pow2N/A
lower-pow.f3296.5
Applied rewrites96.5%
lift-*.f32N/A
lift-log.f32N/A
log-pow-revN/A
lift-pow.f32N/A
unpow2N/A
unpow-prod-downN/A
lift-/.f32N/A
frac-2negN/A
lift-*.f32N/A
distribute-lft-neg-outN/A
lift-neg.f32N/A
lift-*.f32N/A
metadata-evalN/A
lift-/.f32N/A
frac-2negN/A
lift-*.f32N/A
distribute-lft-neg-outN/A
lift-neg.f32N/A
lift-*.f32N/A
metadata-evalN/A
Applied rewrites97.1%
if 0.959999979 < (-.f32 #s(literal 1 binary32) u0) Initial program 49.1%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
metadata-evalN/A
distribute-lft-neg-inN/A
lower--.f32N/A
distribute-lft-neg-inN/A
metadata-evalN/A
lower-*.f3298.6
Applied rewrites98.6%
(FPCore (alpha u0) :precision binary32 (* (* (- alpha) alpha) (* (- (* (- (* (- (* -0.25 u0) 0.3333333333333333) u0) 0.5) u0) 1.0) u0)))
float code(float alpha, float u0) {
return (-alpha * alpha) * (((((((-0.25f * u0) - 0.3333333333333333f) * u0) - 0.5f) * u0) - 1.0f) * u0);
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (-alpha * alpha) * ((((((((-0.25e0) * u0) - 0.3333333333333333e0) * u0) - 0.5e0) * u0) - 1.0e0) * u0)
end function
function code(alpha, u0) return Float32(Float32(Float32(-alpha) * alpha) * Float32(Float32(Float32(Float32(Float32(Float32(Float32(Float32(-0.25) * u0) - Float32(0.3333333333333333)) * u0) - Float32(0.5)) * u0) - Float32(1.0)) * u0)) end
function tmp = code(alpha, u0) tmp = (-alpha * alpha) * (((((((single(-0.25) * u0) - single(0.3333333333333333)) * u0) - single(0.5)) * u0) - single(1.0)) * u0); end
\begin{array}{l}
\\
\left(\left(-\alpha\right) \cdot \alpha\right) \cdot \left(\left(\left(\left(-0.25 \cdot u0 - 0.3333333333333333\right) \cdot u0 - 0.5\right) \cdot u0 - 1\right) \cdot u0\right)
\end{array}
Initial program 56.2%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
metadata-evalN/A
distribute-lft-neg-inN/A
lower--.f32N/A
distribute-lft-neg-inN/A
metadata-evalN/A
lower-*.f3293.0
Applied rewrites93.0%
(FPCore (alpha u0) :precision binary32 (* (* (* (- (* (- (* (- (* -0.25 u0) 0.3333333333333333) u0) 0.5) u0) 1.0) u0) (- alpha)) alpha))
float code(float alpha, float u0) {
return ((((((((-0.25f * u0) - 0.3333333333333333f) * u0) - 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 = (((((((((-0.25e0) * u0) - 0.3333333333333333e0) * u0) - 0.5e0) * u0) - 1.0e0) * u0) * -alpha) * alpha
end function
function code(alpha, u0) return Float32(Float32(Float32(Float32(Float32(Float32(Float32(Float32(Float32(Float32(-0.25) * u0) - Float32(0.3333333333333333)) * u0) - Float32(0.5)) * u0) - Float32(1.0)) * u0) * Float32(-alpha)) * alpha) end
function tmp = code(alpha, u0) tmp = ((((((((single(-0.25) * u0) - single(0.3333333333333333)) * u0) - single(0.5)) * u0) - single(1.0)) * u0) * -alpha) * alpha; end
\begin{array}{l}
\\
\left(\left(\left(\left(\left(-0.25 \cdot u0 - 0.3333333333333333\right) \cdot u0 - 0.5\right) \cdot u0 - 1\right) \cdot u0\right) \cdot \left(-\alpha\right)\right) \cdot \alpha
\end{array}
Initial program 56.2%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
metadata-evalN/A
distribute-lft-neg-inN/A
lower--.f32N/A
distribute-lft-neg-inN/A
metadata-evalN/A
lower-*.f3293.0
Applied rewrites93.0%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f3293.0
Applied rewrites93.0%
(FPCore (alpha u0) :precision binary32 (* (+ (* (* u0 alpha) (* (- 0.5 (* -0.3333333333333333 u0)) alpha)) (* alpha alpha)) u0))
float code(float alpha, float u0) {
return (((u0 * alpha) * ((0.5f - (-0.3333333333333333f * u0)) * alpha)) + (alpha * alpha)) * u0;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = (((u0 * alpha) * ((0.5e0 - ((-0.3333333333333333e0) * u0)) * alpha)) + (alpha * alpha)) * u0
end function
function code(alpha, u0) return Float32(Float32(Float32(Float32(u0 * alpha) * Float32(Float32(Float32(0.5) - Float32(Float32(-0.3333333333333333) * u0)) * alpha)) + Float32(alpha * alpha)) * u0) end
function tmp = code(alpha, u0) tmp = (((u0 * alpha) * ((single(0.5) - (single(-0.3333333333333333) * u0)) * alpha)) + (alpha * alpha)) * u0; end
\begin{array}{l}
\\
\left(\left(u0 \cdot \alpha\right) \cdot \left(\left(0.5 - -0.3333333333333333 \cdot u0\right) \cdot \alpha\right) + \alpha \cdot \alpha\right) \cdot u0
\end{array}
Initial program 56.2%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-fma.f32N/A
*-commutativeN/A
associate-*r*N/A
distribute-rgt-outN/A
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
lower-fma.f32N/A
unpow2N/A
lower-*.f3274.1
Applied rewrites73.9%
Applied rewrites86.1%
Applied rewrites91.2%
(FPCore (alpha u0) :precision binary32 (* (* (* (- (* (- (* -0.3333333333333333 u0) 0.5) u0) 1.0) u0) (- alpha)) alpha))
float code(float alpha, float u0) {
return ((((((-0.3333333333333333f * u0) - 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 = (((((((-0.3333333333333333e0) * u0) - 0.5e0) * u0) - 1.0e0) * u0) * -alpha) * alpha
end function
function code(alpha, u0) return Float32(Float32(Float32(Float32(Float32(Float32(Float32(Float32(-0.3333333333333333) * u0) - Float32(0.5)) * u0) - Float32(1.0)) * u0) * Float32(-alpha)) * alpha) end
function tmp = code(alpha, u0) tmp = ((((((single(-0.3333333333333333) * u0) - single(0.5)) * u0) - single(1.0)) * u0) * -alpha) * alpha; end
\begin{array}{l}
\\
\left(\left(\left(\left(-0.3333333333333333 \cdot u0 - 0.5\right) \cdot u0 - 1\right) \cdot u0\right) \cdot \left(-\alpha\right)\right) \cdot \alpha
\end{array}
Initial program 56.2%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
metadata-evalN/A
distribute-lft-neg-inN/A
lower--.f32N/A
distribute-lft-neg-inN/A
metadata-evalN/A
lower-*.f3293.0
Applied rewrites93.0%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f3293.0
Applied rewrites93.0%
Taylor expanded in u0 around 0
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower--.f32N/A
lower-*.f3290.9
Applied rewrites90.9%
(FPCore (alpha u0) :precision binary32 (* (* (- alpha (* -0.5 (* alpha u0))) u0) alpha))
float code(float alpha, float u0) {
return ((alpha - (-0.5f * (alpha * u0))) * u0) * alpha;
}
real(4) function code(alpha, u0)
real(4), intent (in) :: alpha
real(4), intent (in) :: u0
code = ((alpha - ((-0.5e0) * (alpha * u0))) * u0) * alpha
end function
function code(alpha, u0) return Float32(Float32(Float32(alpha - Float32(Float32(-0.5) * Float32(alpha * u0))) * u0) * alpha) end
function tmp = code(alpha, u0) tmp = ((alpha - (single(-0.5) * (alpha * u0))) * u0) * alpha; end
\begin{array}{l}
\\
\left(\left(\alpha - -0.5 \cdot \left(\alpha \cdot u0\right)\right) \cdot u0\right) \cdot \alpha
\end{array}
Initial program 56.2%
Taylor expanded in alpha around 0
mul-1-negN/A
unpow2N/A
associate-*l*N/A
*-commutativeN/A
distribute-lft-neg-inN/A
lower-*.f32N/A
distribute-lft-neg-inN/A
mul-1-negN/A
lower-*.f32N/A
mul-1-negN/A
lower-neg.f32N/A
remove-double-negN/A
mul-1-negN/A
*-commutativeN/A
distribute-lft-neg-inN/A
fp-cancel-sign-subN/A
*-commutativeN/A
mul-1-negN/A
lower-log1p.f32N/A
lower-neg.f3274.0
Applied rewrites74.0%
Taylor expanded in u0 around 0
Applied rewrites73.8%
Applied rewrites87.0%
(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 56.2%
Taylor expanded in u0 around 0
lower-*.f32N/A
unpow2N/A
lower-*.f3274.1
Applied rewrites74.1%
herbie shell --seed 2024326
(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))))