
(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 8 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 99.4%
(FPCore (u v)
:precision binary32
(+
1.0
(*
v
(log
(+
u
(/
(- 1.0 u)
(+ 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 + ((((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 + ((((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(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(2.0) + (single(1.3333333333333333) / v)) / v) - single(-2.0)) / v)))))); end
\begin{array}{l}
\\
1 + v \cdot \log \left(u + \frac{1 - u}{1 + \frac{\frac{2 + \frac{1.3333333333333333}{v}}{v} - -2}{v}}\right)
\end{array}
Initial program 99.4%
+-commutativeN/A
+-lowering-+.f32N/A
*-lowering-*.f32N/A
log-lowering-log.f32N/A
+-lowering-+.f32N/A
frac-2negN/A
distribute-frac-neg2N/A
exp-negN/A
un-div-invN/A
/-lowering-/.f32N/A
--lowering--.f32N/A
exp-lowering-exp.f32N/A
/-lowering-/.f32N/A
metadata-eval99.4%
Applied egg-rr99.4%
Taylor expanded in v around -inf
mul-1-negN/A
unsub-negN/A
--lowering--.f32N/A
/-lowering-/.f32N/A
sub-negN/A
metadata-evalN/A
+-lowering-+.f32N/A
mul-1-negN/A
distribute-neg-frac2N/A
mul-1-negN/A
/-lowering-/.f32N/A
+-lowering-+.f32N/A
associate-*r/N/A
metadata-evalN/A
/-lowering-/.f32N/A
mul-1-negN/A
neg-lowering-neg.f3295.5%
Simplified95.5%
Final simplification95.5%
(FPCore (u v) :precision binary32 (+ 1.0 (* v (log u))))
float code(float u, float v) {
return 1.0f + (v * logf(u));
}
real(4) function code(u, v)
real(4), intent (in) :: u
real(4), intent (in) :: v
code = 1.0e0 + (v * log(u))
end function
function code(u, v) return Float32(Float32(1.0) + Float32(v * log(u))) end
function tmp = code(u, v) tmp = single(1.0) + (v * log(u)); end
\begin{array}{l}
\\
1 + v \cdot \log u
\end{array}
Initial program 99.4%
+-commutativeN/A
+-lowering-+.f32N/A
*-lowering-*.f32N/A
log-lowering-log.f32N/A
+-lowering-+.f32N/A
frac-2negN/A
distribute-frac-neg2N/A
exp-negN/A
un-div-invN/A
/-lowering-/.f32N/A
--lowering--.f32N/A
exp-lowering-exp.f32N/A
/-lowering-/.f32N/A
metadata-eval99.4%
Applied egg-rr99.4%
Taylor expanded in v around -inf
mul-1-negN/A
unsub-negN/A
--lowering--.f32N/A
/-lowering-/.f32N/A
sub-negN/A
metadata-evalN/A
+-lowering-+.f32N/A
mul-1-negN/A
distribute-neg-frac2N/A
mul-1-negN/A
/-lowering-/.f32N/A
+-lowering-+.f32N/A
associate-*r/N/A
metadata-evalN/A
/-lowering-/.f32N/A
mul-1-negN/A
neg-lowering-neg.f3295.5%
Simplified95.5%
Taylor expanded in v around 0
remove-double-negN/A
log-recN/A
mul-1-negN/A
*-lowering-*.f32N/A
mul-1-negN/A
log-recN/A
remove-double-negN/A
log-lowering-log.f3295.0%
Simplified95.0%
Final simplification95.0%
(FPCore (u v)
:precision binary32
(if (<= v 0.10000000149011612)
1.0
(+
1.0
(+
(* (- 1.0 u) -2.0)
(/
(+
(/
(+
(*
(+
(* (- 1.0 u) 8.0)
(* (* (- 1.0 u) (- 1.0 u)) (+ (* (- 1.0 u) 16.0) -24.0)))
-0.16666666666666666)
(/
(*
0.041666666666666664
(* u (+ 16.0 (* u (+ (* u (+ 192.0 (* u -96.0))) -112.0)))))
v))
v)
(* -0.5 (* (- 1.0 u) (- (* -4.0 (+ u -1.0)) 4.0))))
v)))))
float code(float u, float v) {
float tmp;
if (v <= 0.10000000149011612f) {
tmp = 1.0f;
} else {
tmp = 1.0f + (((1.0f - u) * -2.0f) + ((((((((1.0f - u) * 8.0f) + (((1.0f - u) * (1.0f - u)) * (((1.0f - u) * 16.0f) + -24.0f))) * -0.16666666666666666f) + ((0.041666666666666664f * (u * (16.0f + (u * ((u * (192.0f + (u * -96.0f))) + -112.0f))))) / v)) / v) + (-0.5f * ((1.0f - u) * ((-4.0f * (u + -1.0f)) - 4.0f)))) / v));
}
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 = 1.0e0 + (((1.0e0 - u) * (-2.0e0)) + ((((((((1.0e0 - u) * 8.0e0) + (((1.0e0 - u) * (1.0e0 - u)) * (((1.0e0 - u) * 16.0e0) + (-24.0e0)))) * (-0.16666666666666666e0)) + ((0.041666666666666664e0 * (u * (16.0e0 + (u * ((u * (192.0e0 + (u * (-96.0e0)))) + (-112.0e0)))))) / v)) / v) + ((-0.5e0) * ((1.0e0 - u) * (((-4.0e0) * (u + (-1.0e0))) - 4.0e0)))) / v))
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(1.0) + Float32(Float32(Float32(Float32(1.0) - u) * Float32(-2.0)) + Float32(Float32(Float32(Float32(Float32(Float32(Float32(Float32(Float32(1.0) - u) * Float32(8.0)) + Float32(Float32(Float32(Float32(1.0) - u) * Float32(Float32(1.0) - u)) * Float32(Float32(Float32(Float32(1.0) - u) * Float32(16.0)) + Float32(-24.0)))) * Float32(-0.16666666666666666)) + Float32(Float32(Float32(0.041666666666666664) * Float32(u * Float32(Float32(16.0) + Float32(u * Float32(Float32(u * Float32(Float32(192.0) + Float32(u * Float32(-96.0)))) + Float32(-112.0)))))) / v)) / v) + Float32(Float32(-0.5) * Float32(Float32(Float32(1.0) - u) * Float32(Float32(Float32(-4.0) * Float32(u + Float32(-1.0))) - Float32(4.0))))) / v))); 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 = single(1.0) + (((single(1.0) - u) * single(-2.0)) + ((((((((single(1.0) - u) * single(8.0)) + (((single(1.0) - u) * (single(1.0) - u)) * (((single(1.0) - u) * single(16.0)) + single(-24.0)))) * single(-0.16666666666666666)) + ((single(0.041666666666666664) * (u * (single(16.0) + (u * ((u * (single(192.0) + (u * single(-96.0)))) + single(-112.0)))))) / v)) / v) + (single(-0.5) * ((single(1.0) - u) * ((single(-4.0) * (u + single(-1.0))) - single(4.0))))) / v)); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;v \leq 0.10000000149011612:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;1 + \left(\left(1 - u\right) \cdot -2 + \frac{\frac{\left(\left(1 - u\right) \cdot 8 + \left(\left(1 - u\right) \cdot \left(1 - u\right)\right) \cdot \left(\left(1 - u\right) \cdot 16 + -24\right)\right) \cdot -0.16666666666666666 + \frac{0.041666666666666664 \cdot \left(u \cdot \left(16 + u \cdot \left(u \cdot \left(192 + u \cdot -96\right) + -112\right)\right)\right)}{v}}{v} + -0.5 \cdot \left(\left(1 - u\right) \cdot \left(-4 \cdot \left(u + -1\right) - 4\right)\right)}{v}\right)\\
\end{array}
\end{array}
if v < 0.100000001Initial program 100.0%
Taylor expanded in v around 0
Simplified93.0%
if 0.100000001 < v Initial program 91.9%
Taylor expanded in v around -inf
Simplified65.4%
Taylor expanded in u around 0
*-lowering-*.f32N/A
+-lowering-+.f32N/A
*-lowering-*.f32N/A
sub-negN/A
metadata-evalN/A
+-lowering-+.f32N/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
*-commutativeN/A
*-lowering-*.f3265.4%
Simplified65.4%
Final simplification91.2%
(FPCore (u v)
:precision binary32
(let* ((t_0 (* v (* v v))))
(if (<= v 0.10000000149011612)
1.0
(+
1.0
(+
-2.0
(*
u
(+
(+
2.0
(+
(/ 0.6666666666666666 t_0)
(+ (/ 2.0 v) (/ 1.3333333333333333 (* v v)))))
(*
u
(-
(* u (+ (/ 2.6666666666666665 (* v v)) (/ 8.0 t_0)))
(+ (/ 2.0 v) (+ (/ 4.0 (* v v)) (/ 4.666666666666667 t_0))))))))))))
float code(float u, float v) {
float t_0 = v * (v * v);
float tmp;
if (v <= 0.10000000149011612f) {
tmp = 1.0f;
} else {
tmp = 1.0f + (-2.0f + (u * ((2.0f + ((0.6666666666666666f / t_0) + ((2.0f / v) + (1.3333333333333333f / (v * v))))) + (u * ((u * ((2.6666666666666665f / (v * v)) + (8.0f / t_0))) - ((2.0f / v) + ((4.0f / (v * v)) + (4.666666666666667f / t_0))))))));
}
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 = v * (v * v)
if (v <= 0.10000000149011612e0) then
tmp = 1.0e0
else
tmp = 1.0e0 + ((-2.0e0) + (u * ((2.0e0 + ((0.6666666666666666e0 / t_0) + ((2.0e0 / v) + (1.3333333333333333e0 / (v * v))))) + (u * ((u * ((2.6666666666666665e0 / (v * v)) + (8.0e0 / t_0))) - ((2.0e0 / v) + ((4.0e0 / (v * v)) + (4.666666666666667e0 / t_0))))))))
end if
code = tmp
end function
function code(u, v) t_0 = Float32(v * Float32(v * v)) tmp = Float32(0.0) if (v <= Float32(0.10000000149011612)) tmp = Float32(1.0); else tmp = Float32(Float32(1.0) + Float32(Float32(-2.0) + Float32(u * Float32(Float32(Float32(2.0) + Float32(Float32(Float32(0.6666666666666666) / t_0) + Float32(Float32(Float32(2.0) / v) + Float32(Float32(1.3333333333333333) / Float32(v * v))))) + Float32(u * Float32(Float32(u * Float32(Float32(Float32(2.6666666666666665) / Float32(v * v)) + Float32(Float32(8.0) / t_0))) - Float32(Float32(Float32(2.0) / v) + Float32(Float32(Float32(4.0) / Float32(v * v)) + Float32(Float32(4.666666666666667) / t_0))))))))); end return tmp end
function tmp_2 = code(u, v) t_0 = v * (v * v); tmp = single(0.0); if (v <= single(0.10000000149011612)) tmp = single(1.0); else tmp = single(1.0) + (single(-2.0) + (u * ((single(2.0) + ((single(0.6666666666666666) / t_0) + ((single(2.0) / v) + (single(1.3333333333333333) / (v * v))))) + (u * ((u * ((single(2.6666666666666665) / (v * v)) + (single(8.0) / t_0))) - ((single(2.0) / v) + ((single(4.0) / (v * v)) + (single(4.666666666666667) / t_0)))))))); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
t_0 := v \cdot \left(v \cdot v\right)\\
\mathbf{if}\;v \leq 0.10000000149011612:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;1 + \left(-2 + u \cdot \left(\left(2 + \left(\frac{0.6666666666666666}{t\_0} + \left(\frac{2}{v} + \frac{1.3333333333333333}{v \cdot v}\right)\right)\right) + u \cdot \left(u \cdot \left(\frac{2.6666666666666665}{v \cdot v} + \frac{8}{t\_0}\right) - \left(\frac{2}{v} + \left(\frac{4}{v \cdot v} + \frac{4.666666666666667}{t\_0}\right)\right)\right)\right)\right)\\
\end{array}
\end{array}
if v < 0.100000001Initial program 100.0%
Taylor expanded in v around 0
Simplified93.0%
if 0.100000001 < v Initial program 91.9%
Taylor expanded in v around -inf
Simplified65.4%
Taylor expanded in u around 0
Simplified63.5%
Final simplification91.1%
(FPCore (u v)
:precision binary32
(if (<= v 0.10000000149011612)
1.0
(+
1.0
(+
-2.0
(*
u
(+
2.0
(/
(+
(+ 2.0 (* u -2.0))
(/ (+ (+ 1.3333333333333333 (/ 0.6666666666666666 v)) (* u -4.0)) v))
v)))))))
float code(float u, float v) {
float tmp;
if (v <= 0.10000000149011612f) {
tmp = 1.0f;
} else {
tmp = 1.0f + (-2.0f + (u * (2.0f + (((2.0f + (u * -2.0f)) + (((1.3333333333333333f + (0.6666666666666666f / v)) + (u * -4.0f)) / v)) / v))));
}
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 = 1.0e0 + ((-2.0e0) + (u * (2.0e0 + (((2.0e0 + (u * (-2.0e0))) + (((1.3333333333333333e0 + (0.6666666666666666e0 / v)) + (u * (-4.0e0))) / v)) / v))))
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(1.0) + Float32(Float32(-2.0) + Float32(u * Float32(Float32(2.0) + Float32(Float32(Float32(Float32(2.0) + Float32(u * Float32(-2.0))) + Float32(Float32(Float32(Float32(1.3333333333333333) + Float32(Float32(0.6666666666666666) / v)) + Float32(u * Float32(-4.0))) / v)) / v))))); 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 = single(1.0) + (single(-2.0) + (u * (single(2.0) + (((single(2.0) + (u * single(-2.0))) + (((single(1.3333333333333333) + (single(0.6666666666666666) / v)) + (u * single(-4.0))) / v)) / v)))); end tmp_2 = tmp; end
\begin{array}{l}
\\
\begin{array}{l}
\mathbf{if}\;v \leq 0.10000000149011612:\\
\;\;\;\;1\\
\mathbf{else}:\\
\;\;\;\;1 + \left(-2 + u \cdot \left(2 + \frac{\left(2 + u \cdot -2\right) + \frac{\left(1.3333333333333333 + \frac{0.6666666666666666}{v}\right) + u \cdot -4}{v}}{v}\right)\right)\\
\end{array}
\end{array}
if v < 0.100000001Initial program 100.0%
Taylor expanded in v around 0
Simplified93.0%
if 0.100000001 < v Initial program 91.9%
Taylor expanded in v around -inf
Simplified65.4%
Taylor expanded in u around 0
*-commutativeN/A
*-lowering-*.f3260.7%
Simplified60.7%
Taylor expanded in u around 0
sub-negN/A
metadata-evalN/A
+-lowering-+.f32N/A
Simplified61.5%
Taylor expanded in v around -inf
mul-1-negN/A
distribute-neg-frac2N/A
mul-1-negN/A
/-lowering-/.f32N/A
Simplified61.5%
Final simplification91.0%
(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 99.4%
Taylor expanded in v around 0
Simplified87.4%
(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 99.4%
Taylor expanded in u around 0
Simplified5.1%
herbie shell --seed 2024164
(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))))))))