
(FPCore (u v) :precision binary32 (+ 1.0 (* v (log (+ u (* (- 1.0 u) (exp (/ -2.0 v))))))))
float code(float u, float v) {
return 1.0f + (v * logf((u + ((1.0f - u) * expf((-2.0f / v))))));
}
real(4) function code(u, v)
real(4), intent (in) :: u
real(4), intent (in) :: v
code = 1.0e0 + (v * log((u + ((1.0e0 - u) * exp(((-2.0e0) / v))))))
end function
function code(u, v) return Float32(Float32(1.0) + Float32(v * log(Float32(u + Float32(Float32(Float32(1.0) - u) * exp(Float32(Float32(-2.0) / v))))))) end
function tmp = code(u, v) tmp = single(1.0) + (v * log((u + ((single(1.0) - u) * exp((single(-2.0) / v)))))); end
\begin{array}{l}
\\
1 + v \cdot \log \left(u + \left(1 - u\right) \cdot e^{\frac{-2}{v}}\right)
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 11 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (u v) :precision binary32 (+ 1.0 (* v (log (+ u (* (- 1.0 u) (exp (/ -2.0 v))))))))
float code(float u, float v) {
return 1.0f + (v * logf((u + ((1.0f - u) * expf((-2.0f / v))))));
}
real(4) function code(u, v)
real(4), intent (in) :: u
real(4), intent (in) :: v
code = 1.0e0 + (v * log((u + ((1.0e0 - u) * exp(((-2.0e0) / v))))))
end function
function code(u, v) return Float32(Float32(1.0) + Float32(v * log(Float32(u + Float32(Float32(Float32(1.0) - u) * exp(Float32(Float32(-2.0) / v))))))) end
function tmp = code(u, v) tmp = single(1.0) + (v * log((u + ((single(1.0) - u) * exp((single(-2.0) / v)))))); end
\begin{array}{l}
\\
1 + v \cdot \log \left(u + \left(1 - u\right) \cdot e^{\frac{-2}{v}}\right)
\end{array}
(FPCore (u v) :precision binary32 (+ 1.0 (* v (log (+ u (* (- 1.0 u) (exp (/ -2.0 v))))))))
float code(float u, float v) {
return 1.0f + (v * logf((u + ((1.0f - u) * expf((-2.0f / v))))));
}
real(4) function code(u, v)
real(4), intent (in) :: u
real(4), intent (in) :: v
code = 1.0e0 + (v * log((u + ((1.0e0 - u) * exp(((-2.0e0) / v))))))
end function
function code(u, v) return Float32(Float32(1.0) + Float32(v * log(Float32(u + Float32(Float32(Float32(1.0) - u) * exp(Float32(Float32(-2.0) / v))))))) end
function tmp = code(u, v) tmp = single(1.0) + (v * log((u + ((single(1.0) - u) * exp((single(-2.0) / v)))))); end
\begin{array}{l}
\\
1 + v \cdot \log \left(u + \left(1 - u\right) \cdot e^{\frac{-2}{v}}\right)
\end{array}
Initial program 99.5%
(FPCore (u v) :precision binary32 (if (<= (* v (log (+ u (* (- 1.0 u) (exp (/ -2.0 v)))))) -1.0) (+ -1.0 (* u 2.0)) 1.0))
float code(float u, float v) {
float tmp;
if ((v * logf((u + ((1.0f - u) * expf((-2.0f / v)))))) <= -1.0f) {
tmp = -1.0f + (u * 2.0f);
} else {
tmp = 1.0f;
}
return tmp;
}
real(4) function code(u, v)
real(4), intent (in) :: u
real(4), intent (in) :: v
real(4) :: tmp
if ((v * log((u + ((1.0e0 - u) * exp(((-2.0e0) / v)))))) <= (-1.0e0)) then
tmp = (-1.0e0) + (u * 2.0e0)
else
tmp = 1.0e0
end if
code = tmp
end function
function code(u, v) tmp = Float32(0.0) if (Float32(v * log(Float32(u + Float32(Float32(Float32(1.0) - u) * exp(Float32(Float32(-2.0) / v)))))) <= Float32(-1.0)) tmp = Float32(Float32(-1.0) + Float32(u * Float32(2.0))); else tmp = Float32(1.0); end return tmp end
function tmp_2 = code(u, v) tmp = single(0.0); if ((v * log((u + ((single(1.0) - u) * exp((single(-2.0) / v)))))) <= single(-1.0)) tmp = single(-1.0) + (u * single(2.0)); else tmp = single(1.0); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;v \cdot \log \left(u + \left(1 - u\right) \cdot e^{\frac{-2}{v}}\right) \leq -1:\\
\;\;\;\;-1 + u \cdot 2\\
\mathbf{else}:\\
\;\;\;\;1\\
\end{array}
\end{array}
if (*.f32 v (log.f32 (+.f32 u (*.f32 (-.f32 #s(literal 1 binary32) u) (exp.f32 (/.f32 #s(literal -2 binary32) v)))))) < -1Initial program 93.8%
Taylor expanded in v around -inf
mul-1-negN/A
distribute-neg-frac2N/A
lower-/.f32N/A
Applied rewrites3.3%
Taylor expanded in v around inf
distribute-lft-inN/A
metadata-evalN/A
associate-+r+N/A
metadata-evalN/A
associate-*r*N/A
metadata-evalN/A
lower-+.f32N/A
*-commutativeN/A
lower-*.f3251.6
Applied rewrites51.6%
if -1 < (*.f32 v (log.f32 (+.f32 u (*.f32 (-.f32 #s(literal 1 binary32) u) (exp.f32 (/.f32 #s(literal -2 binary32) v)))))) Initial program 100.0%
Taylor expanded in v around 0
Applied rewrites93.0%
(FPCore (u v) :precision binary32 (+ 1.0 (* v (log (+ u (exp (/ -2.0 v)))))))
float code(float u, float v) {
return 1.0f + (v * logf((u + expf((-2.0f / v)))));
}
real(4) function code(u, v)
real(4), intent (in) :: u
real(4), intent (in) :: v
code = 1.0e0 + (v * log((u + exp(((-2.0e0) / v)))))
end function
function code(u, v) return Float32(Float32(1.0) + Float32(v * log(Float32(u + exp(Float32(Float32(-2.0) / v)))))) end
function tmp = code(u, v) tmp = single(1.0) + (v * log((u + exp((single(-2.0) / v))))); end
\begin{array}{l}
\\
1 + v \cdot \log \left(u + e^{\frac{-2}{v}}\right)
\end{array}
Initial program 99.5%
lift-/.f32N/A
*-lft-identityN/A
exp-prodN/A
lift-/.f32N/A
frac-2negN/A
distribute-frac-neg2N/A
pow-negN/A
lower-/.f32N/A
lower-pow.f32N/A
exp-1-eN/A
lower-E.f32N/A
lower-/.f32N/A
metadata-eval99.4
Applied rewrites99.4%
Taylor expanded in u around 0
rec-expN/A
log-EN/A
distribute-lft-neg-inN/A
lower-exp.f32N/A
metadata-evalN/A
associate-*r/N/A
metadata-evalN/A
lower-/.f3295.4
Applied rewrites95.4%
(FPCore (u v)
:precision binary32
(+
1.0
(*
v
(log
(+
u
(*
(- 1.0 u)
(/
1.0
(+ 1.0 (/ (- (/ (+ 2.0 (/ 1.3333333333333333 v)) v) -2.0) v)))))))))
float code(float u, float v) {
return 1.0f + (v * logf((u + ((1.0f - u) * (1.0f / (1.0f + ((((2.0f + (1.3333333333333333f / v)) / v) - -2.0f) / v)))))));
}
real(4) function code(u, v)
real(4), intent (in) :: u
real(4), intent (in) :: v
code = 1.0e0 + (v * log((u + ((1.0e0 - u) * (1.0e0 / (1.0e0 + ((((2.0e0 + (1.3333333333333333e0 / v)) / v) - (-2.0e0)) / v)))))))
end function
function code(u, v) return Float32(Float32(1.0) + Float32(v * log(Float32(u + Float32(Float32(Float32(1.0) - u) * Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(Float32(Float32(Float32(Float32(2.0) + Float32(Float32(1.3333333333333333) / v)) / v) - Float32(-2.0)) / v)))))))) end
function tmp = code(u, v) tmp = single(1.0) + (v * log((u + ((single(1.0) - u) * (single(1.0) / (single(1.0) + ((((single(2.0) + (single(1.3333333333333333) / v)) / v) - single(-2.0)) / v))))))); end
\begin{array}{l}
\\
1 + v \cdot \log \left(u + \left(1 - u\right) \cdot \frac{1}{1 + \frac{\frac{2 + \frac{1.3333333333333333}{v}}{v} - -2}{v}}\right)
\end{array}
Initial program 99.5%
lift-/.f32N/A
*-lft-identityN/A
exp-prodN/A
lift-/.f32N/A
frac-2negN/A
distribute-frac-neg2N/A
pow-negN/A
lower-/.f32N/A
lower-pow.f32N/A
exp-1-eN/A
lower-E.f32N/A
lower-/.f32N/A
metadata-eval99.4
Applied rewrites99.4%
Taylor expanded in v around -inf
mul-1-negN/A
unsub-negN/A
lower--.f32N/A
lower-/.f32N/A
Applied rewrites94.2%
Final simplification94.2%
(FPCore (u v) :precision binary32 (+ 1.0 (* v (log (+ u (* (- 1.0 u) (/ 1.0 (- 1.0 (/ (+ -2.0 (/ -2.0 v)) v)))))))))
float code(float u, float v) {
return 1.0f + (v * logf((u + ((1.0f - u) * (1.0f / (1.0f - ((-2.0f + (-2.0f / v)) / v)))))));
}
real(4) function code(u, v)
real(4), intent (in) :: u
real(4), intent (in) :: v
code = 1.0e0 + (v * log((u + ((1.0e0 - u) * (1.0e0 / (1.0e0 - (((-2.0e0) + ((-2.0e0) / v)) / v)))))))
end function
function code(u, v) return Float32(Float32(1.0) + Float32(v * log(Float32(u + Float32(Float32(Float32(1.0) - u) * Float32(Float32(1.0) / Float32(Float32(1.0) - Float32(Float32(Float32(-2.0) + Float32(Float32(-2.0) / v)) / v)))))))) end
function tmp = code(u, v) tmp = single(1.0) + (v * log((u + ((single(1.0) - u) * (single(1.0) / (single(1.0) - ((single(-2.0) + (single(-2.0) / v)) / v))))))); end
\begin{array}{l}
\\
1 + v \cdot \log \left(u + \left(1 - u\right) \cdot \frac{1}{1 - \frac{-2 + \frac{-2}{v}}{v}}\right)
\end{array}
Initial program 99.5%
lift-/.f32N/A
*-lft-identityN/A
exp-prodN/A
lift-/.f32N/A
frac-2negN/A
distribute-frac-neg2N/A
pow-negN/A
lower-/.f32N/A
lower-pow.f32N/A
exp-1-eN/A
lower-E.f32N/A
lower-/.f32N/A
metadata-eval99.4
Applied rewrites99.4%
Taylor expanded in v around -inf
mul-1-negN/A
unsub-negN/A
lower--.f32N/A
log-EN/A
metadata-evalN/A
metadata-evalN/A
log-EN/A
metadata-evalN/A
metadata-evalN/A
distribute-lft-neg-inN/A
distribute-neg-inN/A
mul-1-negN/A
lower-/.f32N/A
Applied rewrites92.6%
(FPCore (u v) :precision binary32 (+ 1.0 (* v (log (+ u (* (- 1.0 u) (/ 1.0 (+ 1.0 (/ 2.0 v)))))))))
float code(float u, float v) {
return 1.0f + (v * logf((u + ((1.0f - u) * (1.0f / (1.0f + (2.0f / v)))))));
}
real(4) function code(u, v)
real(4), intent (in) :: u
real(4), intent (in) :: v
code = 1.0e0 + (v * log((u + ((1.0e0 - u) * (1.0e0 / (1.0e0 + (2.0e0 / v)))))))
end function
function code(u, v) return Float32(Float32(1.0) + Float32(v * log(Float32(u + Float32(Float32(Float32(1.0) - u) * Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(Float32(2.0) / v)))))))) end
function tmp = code(u, v) tmp = single(1.0) + (v * log((u + ((single(1.0) - u) * (single(1.0) / (single(1.0) + (single(2.0) / v))))))); end
\begin{array}{l}
\\
1 + v \cdot \log \left(u + \left(1 - u\right) \cdot \frac{1}{1 + \frac{2}{v}}\right)
\end{array}
Initial program 99.5%
lift-/.f32N/A
*-lft-identityN/A
exp-prodN/A
lift-/.f32N/A
frac-2negN/A
distribute-frac-neg2N/A
pow-negN/A
lower-/.f32N/A
lower-pow.f32N/A
exp-1-eN/A
lower-E.f32N/A
lower-/.f32N/A
metadata-eval99.4
Applied rewrites99.4%
Taylor expanded in v around inf
log-EN/A
lower-+.f32N/A
associate-*r/N/A
metadata-evalN/A
lower-/.f3290.6
Applied rewrites90.6%
(FPCore (u v)
:precision binary32
(let* ((t_0 (/ -2.0 (* v v))))
(if (<= v 0.10000000149011612)
1.0
(+
1.0
(*
v
(*
(* u u)
(+
t_0
(/
(- (/ (+ t_0 (/ (+ -2.0 (/ 2.0 v)) v)) u) (+ (/ -2.0 v) t_0))
u))))))))
float code(float u, float v) {
float t_0 = -2.0f / (v * v);
float tmp;
if (v <= 0.10000000149011612f) {
tmp = 1.0f;
} else {
tmp = 1.0f + (v * ((u * u) * (t_0 + ((((t_0 + ((-2.0f + (2.0f / v)) / v)) / u) - ((-2.0f / v) + t_0)) / u))));
}
return tmp;
}
real(4) function code(u, v)
real(4), intent (in) :: u
real(4), intent (in) :: v
real(4) :: t_0
real(4) :: tmp
t_0 = (-2.0e0) / (v * v)
if (v <= 0.10000000149011612e0) then
tmp = 1.0e0
else
tmp = 1.0e0 + (v * ((u * u) * (t_0 + ((((t_0 + (((-2.0e0) + (2.0e0 / v)) / v)) / u) - (((-2.0e0) / v) + t_0)) / u))))
end if
code = tmp
end function
function code(u, v) t_0 = Float32(Float32(-2.0) / Float32(v * v)) tmp = Float32(0.0) if (v <= Float32(0.10000000149011612)) tmp = Float32(1.0); else tmp = Float32(Float32(1.0) + Float32(v * Float32(Float32(u * u) * Float32(t_0 + Float32(Float32(Float32(Float32(t_0 + Float32(Float32(Float32(-2.0) + Float32(Float32(2.0) / v)) / v)) / u) - Float32(Float32(Float32(-2.0) / v) + t_0)) / u))))); end return tmp end
function tmp_2 = code(u, v) t_0 = single(-2.0) / (v * v); tmp = single(0.0); if (v <= single(0.10000000149011612)) tmp = single(1.0); else tmp = single(1.0) + (v * ((u * u) * (t_0 + ((((t_0 + ((single(-2.0) + (single(2.0) / v)) / v)) / u) - ((single(-2.0) / v) + t_0)) / u)))); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := \frac{-2}{v \cdot v}\\
\mathbf{if}\;v \leq 0.10000000149011612:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;1 + v \cdot \left(\left(u \cdot u\right) \cdot \left(t\_0 + \frac{\frac{t\_0 + \frac{-2 + \frac{2}{v}}{v}}{u} - \left(\frac{-2}{v} + t\_0\right)}{u}\right)\right)\\
\end{array}
\end{array}
if v < 0.100000001Initial program 100.0%
Taylor expanded in v around 0
Applied rewrites94.1%
if 0.100000001 < v Initial program 94.4%
Taylor expanded in v around -inf
mul-1-negN/A
distribute-neg-frac2N/A
lower-/.f32N/A
Applied rewrites9.0%
Applied rewrites6.8%
lift-fma.f32N/A
lift--.f32N/A
lift--.f32N/A
lift-fma.f32N/A
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
associate-*r*N/A
lift-fma.f32N/A
*-commutativeN/A
lift-fma.f32N/A
lift-*.f32N/A
associate-*l*N/A
lower-*.f32N/A
Applied rewrites6.9%
Taylor expanded in u around -inf
Applied rewrites56.0%
Final simplification90.6%
(FPCore (u v) :precision binary32 (if (<= v 0.10000000149011612) 1.0 (* (* u u) (+ (/ -2.0 v) (/ (- (/ -1.0 u) (+ -2.0 (/ -2.0 v))) u)))))
float code(float u, float v) {
float tmp;
if (v <= 0.10000000149011612f) {
tmp = 1.0f;
} else {
tmp = (u * u) * ((-2.0f / v) + (((-1.0f / u) - (-2.0f + (-2.0f / v))) / u));
}
return tmp;
}
real(4) function code(u, v)
real(4), intent (in) :: u
real(4), intent (in) :: v
real(4) :: tmp
if (v <= 0.10000000149011612e0) then
tmp = 1.0e0
else
tmp = (u * u) * (((-2.0e0) / v) + ((((-1.0e0) / u) - ((-2.0e0) + ((-2.0e0) / v))) / u))
end if
code = tmp
end function
function code(u, v) tmp = Float32(0.0) if (v <= Float32(0.10000000149011612)) tmp = Float32(1.0); else tmp = Float32(Float32(u * u) * Float32(Float32(Float32(-2.0) / v) + Float32(Float32(Float32(Float32(-1.0) / u) - Float32(Float32(-2.0) + Float32(Float32(-2.0) / v))) / u))); end return tmp end
function tmp_2 = code(u, v) tmp = single(0.0); if (v <= single(0.10000000149011612)) tmp = single(1.0); else tmp = (u * u) * ((single(-2.0) / v) + (((single(-1.0) / u) - (single(-2.0) + (single(-2.0) / v))) / u)); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;v \leq 0.10000000149011612:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;\left(u \cdot u\right) \cdot \left(\frac{-2}{v} + \frac{\frac{-1}{u} - \left(-2 + \frac{-2}{v}\right)}{u}\right)\\
\end{array}
\end{array}
if v < 0.100000001Initial program 100.0%
Taylor expanded in v around 0
Applied rewrites94.1%
if 0.100000001 < v Initial program 94.4%
Taylor expanded in v around -inf
mul-1-negN/A
distribute-neg-frac2N/A
lower-/.f32N/A
Applied rewrites9.0%
Taylor expanded in u around -inf
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
sub-negN/A
lower-+.f32N/A
Applied rewrites55.9%
Final simplification90.6%
(FPCore (u v) :precision binary32 (if (<= v 0.10000000149011612) 1.0 (* (* u u) (+ (/ -2.0 v) (/ (- (- (/ -1.0 u) (/ -2.0 v)) -2.0) u)))))
float code(float u, float v) {
float tmp;
if (v <= 0.10000000149011612f) {
tmp = 1.0f;
} else {
tmp = (u * u) * ((-2.0f / v) + ((((-1.0f / u) - (-2.0f / v)) - -2.0f) / u));
}
return tmp;
}
real(4) function code(u, v)
real(4), intent (in) :: u
real(4), intent (in) :: v
real(4) :: tmp
if (v <= 0.10000000149011612e0) then
tmp = 1.0e0
else
tmp = (u * u) * (((-2.0e0) / v) + (((((-1.0e0) / u) - ((-2.0e0) / v)) - (-2.0e0)) / u))
end if
code = tmp
end function
function code(u, v) tmp = Float32(0.0) if (v <= Float32(0.10000000149011612)) tmp = Float32(1.0); else tmp = Float32(Float32(u * u) * Float32(Float32(Float32(-2.0) / v) + Float32(Float32(Float32(Float32(Float32(-1.0) / u) - Float32(Float32(-2.0) / v)) - Float32(-2.0)) / u))); end return tmp end
function tmp_2 = code(u, v) tmp = single(0.0); if (v <= single(0.10000000149011612)) tmp = single(1.0); else tmp = (u * u) * ((single(-2.0) / v) + ((((single(-1.0) / u) - (single(-2.0) / v)) - single(-2.0)) / u)); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;v \leq 0.10000000149011612:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;\left(u \cdot u\right) \cdot \left(\frac{-2}{v} + \frac{\left(\frac{-1}{u} - \frac{-2}{v}\right) - -2}{u}\right)\\
\end{array}
\end{array}
if v < 0.100000001Initial program 100.0%
Taylor expanded in v around 0
Applied rewrites94.1%
if 0.100000001 < v Initial program 94.4%
Taylor expanded in v around -inf
mul-1-negN/A
distribute-neg-frac2N/A
lower-/.f32N/A
Applied rewrites9.0%
lift--.f32N/A
*-commutativeN/A
lower-fma.f328.0
Applied rewrites7.0%
Taylor expanded in u around -inf
lower-*.f32N/A
unpow2N/A
lower-*.f32N/A
sub-negN/A
lower-+.f32N/A
Applied rewrites55.9%
Final simplification90.6%
(FPCore (u v) :precision binary32 1.0)
float code(float u, float v) {
return 1.0f;
}
real(4) function code(u, v)
real(4), intent (in) :: u
real(4), intent (in) :: v
code = 1.0e0
end function
function code(u, v) return Float32(1.0) end
function tmp = code(u, v) tmp = single(1.0); end
\begin{array}{l}
\\
1
\end{array}
Initial program 99.5%
Taylor expanded in v around 0
Applied rewrites86.3%
(FPCore (u v) :precision binary32 -1.0)
float code(float u, float v) {
return -1.0f;
}
real(4) function code(u, v)
real(4), intent (in) :: u
real(4), intent (in) :: v
code = -1.0e0
end function
function code(u, v) return Float32(-1.0) end
function tmp = code(u, v) tmp = single(-1.0); end
\begin{array}{l}
\\
-1
\end{array}
Initial program 99.5%
Taylor expanded in u around 0
Applied rewrites6.2%
herbie shell --seed 2024216
(FPCore (u v)
:name "HairBSDF, sample_f, cosTheta"
:precision binary32
:pre (and (and (<= 1e-5 u) (<= u 1.0)) (and (<= 0.0 v) (<= v 109.746574)))
(+ 1.0 (* v (log (+ u (* (- 1.0 u) (exp (/ -2.0 v))))))))