
(FPCore (s r) :precision binary32 (+ (/ (* 0.25 (exp (/ (- r) s))) (* (* (* 2.0 PI) s) r)) (/ (* 0.75 (exp (/ (- r) (* 3.0 s)))) (* (* (* 6.0 PI) s) r))))
float code(float s, float r) {
return ((0.25f * expf((-r / s))) / (((2.0f * ((float) M_PI)) * s) * r)) + ((0.75f * expf((-r / (3.0f * s)))) / (((6.0f * ((float) M_PI)) * s) * r));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) * exp(Float32(Float32(-r) / s))) / Float32(Float32(Float32(Float32(2.0) * Float32(pi)) * s) * r)) + Float32(Float32(Float32(0.75) * exp(Float32(Float32(-r) / Float32(Float32(3.0) * s)))) / Float32(Float32(Float32(Float32(6.0) * Float32(pi)) * s) * r))) end
function tmp = code(s, r) tmp = ((single(0.25) * exp((-r / s))) / (((single(2.0) * single(pi)) * s) * r)) + ((single(0.75) * exp((-r / (single(3.0) * s)))) / (((single(6.0) * single(pi)) * s) * r)); end
\begin{array}{l}
\\
\frac{0.25 \cdot e^{\frac{-r}{s}}}{\left(\left(2 \cdot \pi\right) \cdot s\right) \cdot r} + \frac{0.75 \cdot e^{\frac{-r}{3 \cdot s}}}{\left(\left(6 \cdot \pi\right) \cdot s\right) \cdot r}
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 10 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (s r) :precision binary32 (+ (/ (* 0.25 (exp (/ (- r) s))) (* (* (* 2.0 PI) s) r)) (/ (* 0.75 (exp (/ (- r) (* 3.0 s)))) (* (* (* 6.0 PI) s) r))))
float code(float s, float r) {
return ((0.25f * expf((-r / s))) / (((2.0f * ((float) M_PI)) * s) * r)) + ((0.75f * expf((-r / (3.0f * s)))) / (((6.0f * ((float) M_PI)) * s) * r));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) * exp(Float32(Float32(-r) / s))) / Float32(Float32(Float32(Float32(2.0) * Float32(pi)) * s) * r)) + Float32(Float32(Float32(0.75) * exp(Float32(Float32(-r) / Float32(Float32(3.0) * s)))) / Float32(Float32(Float32(Float32(6.0) * Float32(pi)) * s) * r))) end
function tmp = code(s, r) tmp = ((single(0.25) * exp((-r / s))) / (((single(2.0) * single(pi)) * s) * r)) + ((single(0.75) * exp((-r / (single(3.0) * s)))) / (((single(6.0) * single(pi)) * s) * r)); end
\begin{array}{l}
\\
\frac{0.25 \cdot e^{\frac{-r}{s}}}{\left(\left(2 \cdot \pi\right) \cdot s\right) \cdot r} + \frac{0.75 \cdot e^{\frac{-r}{3 \cdot s}}}{\left(\left(6 \cdot \pi\right) \cdot s\right) \cdot r}
\end{array}
(FPCore (s r) :precision binary32 (/ (/ (+ (exp (- 0.0 (/ r s))) (exp (/ (/ r s) -3.0))) (/ (* r s) 0.125)) PI))
float code(float s, float r) {
return ((expf((0.0f - (r / s))) + expf(((r / s) / -3.0f))) / ((r * s) / 0.125f)) / ((float) M_PI);
}
function code(s, r) return Float32(Float32(Float32(exp(Float32(Float32(0.0) - Float32(r / s))) + exp(Float32(Float32(r / s) / Float32(-3.0)))) / Float32(Float32(r * s) / Float32(0.125))) / Float32(pi)) end
function tmp = code(s, r) tmp = ((exp((single(0.0) - (r / s))) + exp(((r / s) / single(-3.0)))) / ((r * s) / single(0.125))) / single(pi); end
\begin{array}{l}
\\
\frac{\frac{e^{0 - \frac{r}{s}} + e^{\frac{\frac{r}{s}}{-3}}}{\frac{r \cdot s}{0.125}}}{\pi}
\end{array}
Initial program 99.7%
Simplified96.2%
/-lowering-/.f32N/A
Applied egg-rr99.7%
Final simplification99.7%
(FPCore (s r) :precision binary32 (/ (* (+ (exp (- 0.0 (/ r s))) (exp (/ (/ r s) -3.0))) 0.125) (* (* r s) PI)))
float code(float s, float r) {
return ((expf((0.0f - (r / s))) + expf(((r / s) / -3.0f))) * 0.125f) / ((r * s) * ((float) M_PI));
}
function code(s, r) return Float32(Float32(Float32(exp(Float32(Float32(0.0) - Float32(r / s))) + exp(Float32(Float32(r / s) / Float32(-3.0)))) * Float32(0.125)) / Float32(Float32(r * s) * Float32(pi))) end
function tmp = code(s, r) tmp = ((exp((single(0.0) - (r / s))) + exp(((r / s) / single(-3.0)))) * single(0.125)) / ((r * s) * single(pi)); end
\begin{array}{l}
\\
\frac{\left(e^{0 - \frac{r}{s}} + e^{\frac{\frac{r}{s}}{-3}}\right) \cdot 0.125}{\left(r \cdot s\right) \cdot \pi}
\end{array}
Initial program 99.7%
Simplified96.2%
associate-/l*N/A
frac-timesN/A
/-lowering-/.f32N/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
sub0-negN/A
exp-lowering-exp.f32N/A
distribute-frac-neg2N/A
/-lowering-/.f32N/A
neg-lowering-neg.f32N/A
exp-lowering-exp.f32N/A
/-lowering-/.f32N/A
/-lowering-/.f32N/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
PI-lowering-PI.f3299.7%
Applied egg-rr99.7%
Final simplification99.7%
(FPCore (s r) :precision binary32 (* 0.125 (/ (/ (+ (exp (- 0.0 (/ r s))) (exp (/ r (* s -3.0)))) r) (* s PI))))
float code(float s, float r) {
return 0.125f * (((expf((0.0f - (r / s))) + expf((r / (s * -3.0f)))) / r) / (s * ((float) M_PI)));
}
function code(s, r) return Float32(Float32(0.125) * Float32(Float32(Float32(exp(Float32(Float32(0.0) - Float32(r / s))) + exp(Float32(r / Float32(s * Float32(-3.0))))) / r) / Float32(s * Float32(pi)))) end
function tmp = code(s, r) tmp = single(0.125) * (((exp((single(0.0) - (r / s))) + exp((r / (s * single(-3.0))))) / r) / (s * single(pi))); end
\begin{array}{l}
\\
0.125 \cdot \frac{\frac{e^{0 - \frac{r}{s}} + e^{\frac{r}{s \cdot -3}}}{r}}{s \cdot \pi}
\end{array}
Initial program 99.7%
Simplified96.2%
associate-*l/N/A
associate-/r*N/A
/-lowering-/.f32N/A
Applied egg-rr99.7%
associate-/l/N/A
associate-/r*N/A
/-lowering-/.f32N/A
/-lowering-/.f3299.7%
Applied egg-rr99.7%
associate-/l/N/A
associate-/l*N/A
associate-/l*N/A
*-lowering-*.f32N/A
/-lowering-/.f32N/A
Applied egg-rr99.6%
Final simplification99.6%
(FPCore (s r)
:precision binary32
(/
(/
(/
(*
0.125
(+
1.0
(+
(exp (- 0.0 (/ r s)))
(* (/ r s) (+ -0.3333333333333333 (/ (* r 0.05555555555555555) s))))))
s)
r)
PI))
float code(float s, float r) {
return (((0.125f * (1.0f + (expf((0.0f - (r / s))) + ((r / s) * (-0.3333333333333333f + ((r * 0.05555555555555555f) / s)))))) / s) / r) / ((float) M_PI);
}
function code(s, r) return Float32(Float32(Float32(Float32(Float32(0.125) * Float32(Float32(1.0) + Float32(exp(Float32(Float32(0.0) - Float32(r / s))) + Float32(Float32(r / s) * Float32(Float32(-0.3333333333333333) + Float32(Float32(r * Float32(0.05555555555555555)) / s)))))) / s) / r) / Float32(pi)) end
function tmp = code(s, r) tmp = (((single(0.125) * (single(1.0) + (exp((single(0.0) - (r / s))) + ((r / s) * (single(-0.3333333333333333) + ((r * single(0.05555555555555555)) / s)))))) / s) / r) / single(pi); end
\begin{array}{l}
\\
\frac{\frac{\frac{0.125 \cdot \left(1 + \left(e^{0 - \frac{r}{s}} + \frac{r}{s} \cdot \left(-0.3333333333333333 + \frac{r \cdot 0.05555555555555555}{s}\right)\right)\right)}{s}}{r}}{\pi}
\end{array}
Initial program 99.7%
Simplified96.2%
Taylor expanded in s around inf
+-lowering-+.f32N/A
+-lowering-+.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
/-lowering-/.f32N/A
associate-*r/N/A
/-lowering-/.f32N/A
*-commutativeN/A
unpow2N/A
associate-*l*N/A
*-commutativeN/A
*-lowering-*.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
unpow2N/A
*-lowering-*.f329.5%
Simplified9.5%
associate-*l/N/A
*-commutativeN/A
associate-/r*N/A
/-lowering-/.f32N/A
Applied egg-rr9.6%
Final simplification9.6%
(FPCore (s r)
:precision binary32
(/
(/
(+
(/ 0.25 r)
(/ (+ -0.16666666666666666 (/ (* r 0.06944444444444445) s)) s))
s)
PI))
float code(float s, float r) {
return (((0.25f / r) + ((-0.16666666666666666f + ((r * 0.06944444444444445f) / s)) / s)) / s) / ((float) M_PI);
}
function code(s, r) return Float32(Float32(Float32(Float32(Float32(0.25) / r) + Float32(Float32(Float32(-0.16666666666666666) + Float32(Float32(r * Float32(0.06944444444444445)) / s)) / s)) / s) / Float32(pi)) end
function tmp = code(s, r) tmp = (((single(0.25) / r) + ((single(-0.16666666666666666) + ((r * single(0.06944444444444445)) / s)) / s)) / s) / single(pi); end
\begin{array}{l}
\\
\frac{\frac{\frac{0.25}{r} + \frac{-0.16666666666666666 + \frac{r \cdot 0.06944444444444445}{s}}{s}}{s}}{\pi}
\end{array}
Initial program 99.7%
Simplified96.2%
Taylor expanded in r around 0
/-lowering-/.f32N/A
Simplified7.5%
Taylor expanded in s around inf
/-lowering-/.f32N/A
Simplified9.0%
(FPCore (s r) :precision binary32 (/ (/ 0.25 s) (* r PI)))
float code(float s, float r) {
return (0.25f / s) / (r * ((float) M_PI));
}
function code(s, r) return Float32(Float32(Float32(0.25) / s) / Float32(r * Float32(pi))) end
function tmp = code(s, r) tmp = (single(0.25) / s) / (r * single(pi)); end
\begin{array}{l}
\\
\frac{\frac{0.25}{s}}{r \cdot \pi}
\end{array}
Initial program 99.7%
Simplified96.2%
Taylor expanded in r around 0
*-commutativeN/A
associate-/r*N/A
metadata-evalN/A
associate-*r/N/A
/-lowering-/.f32N/A
associate-*r/N/A
metadata-evalN/A
/-lowering-/.f328.4%
Simplified8.4%
associate-/l/N/A
/-lowering-/.f32N/A
/-lowering-/.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
PI-lowering-PI.f328.4%
Applied egg-rr8.4%
(FPCore (s r) :precision binary32 (/ 0.25 (* (* r s) PI)))
float code(float s, float r) {
return 0.25f / ((r * s) * ((float) M_PI));
}
function code(s, r) return Float32(Float32(0.25) / Float32(Float32(r * s) * Float32(pi))) end
function tmp = code(s, r) tmp = single(0.25) / ((r * s) * single(pi)); end
\begin{array}{l}
\\
\frac{0.25}{\left(r \cdot s\right) \cdot \pi}
\end{array}
Initial program 99.7%
Simplified96.2%
Taylor expanded in r around 0
*-commutativeN/A
associate-/r*N/A
metadata-evalN/A
associate-*r/N/A
/-lowering-/.f32N/A
associate-*r/N/A
metadata-evalN/A
/-lowering-/.f328.4%
Simplified8.4%
div-invN/A
associate-/l/N/A
frac-timesN/A
metadata-evalN/A
/-lowering-/.f32N/A
*-lowering-*.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
PI-lowering-PI.f328.4%
Applied egg-rr8.4%
Final simplification8.4%
(FPCore (s r) :precision binary32 (/ 0.25 (* s (* r PI))))
float code(float s, float r) {
return 0.25f / (s * (r * ((float) M_PI)));
}
function code(s, r) return Float32(Float32(0.25) / Float32(s * Float32(r * Float32(pi)))) end
function tmp = code(s, r) tmp = single(0.25) / (s * (r * single(pi))); end
\begin{array}{l}
\\
\frac{0.25}{s \cdot \left(r \cdot \pi\right)}
\end{array}
Initial program 99.7%
Simplified96.2%
Taylor expanded in r around 0
*-commutativeN/A
associate-/r*N/A
metadata-evalN/A
associate-*r/N/A
/-lowering-/.f32N/A
associate-*r/N/A
metadata-evalN/A
/-lowering-/.f328.4%
Simplified8.4%
associate-/l/N/A
associate-/l/N/A
/-lowering-/.f32N/A
*-lowering-*.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
PI-lowering-PI.f328.4%
Applied egg-rr8.4%
Final simplification8.4%
(FPCore (s r) :precision binary32 (/ 0.125 (* (* r s) PI)))
float code(float s, float r) {
return 0.125f / ((r * s) * ((float) M_PI));
}
function code(s, r) return Float32(Float32(0.125) / Float32(Float32(r * s) * Float32(pi))) end
function tmp = code(s, r) tmp = single(0.125) / ((r * s) * single(pi)); end
\begin{array}{l}
\\
\frac{0.125}{\left(r \cdot s\right) \cdot \pi}
\end{array}
Initial program 99.7%
Simplified96.2%
Taylor expanded in s around inf
+-lowering-+.f32N/A
+-lowering-+.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
/-lowering-/.f32N/A
associate-*r/N/A
/-lowering-/.f32N/A
*-commutativeN/A
unpow2N/A
associate-*l*N/A
*-commutativeN/A
*-lowering-*.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
unpow2N/A
*-lowering-*.f329.5%
Simplified9.5%
Taylor expanded in r around inf
associate-*r/N/A
/-lowering-/.f32N/A
*-commutativeN/A
unpow2N/A
associate-*l*N/A
*-commutativeN/A
*-lowering-*.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
unpow2N/A
*-lowering-*.f325.6%
Simplified5.6%
Taylor expanded in r around 0
/-lowering-/.f32N/A
*-commutativeN/A
*-lowering-*.f326.6%
Simplified6.6%
associate-/l/N/A
/-lowering-/.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
PI-lowering-PI.f326.6%
Applied egg-rr6.6%
Final simplification6.6%
(FPCore (s r) :precision binary32 (/ 0.125 (* r (* s PI))))
float code(float s, float r) {
return 0.125f / (r * (s * ((float) M_PI)));
}
function code(s, r) return Float32(Float32(0.125) / Float32(r * Float32(s * Float32(pi)))) end
function tmp = code(s, r) tmp = single(0.125) / (r * (s * single(pi))); end
\begin{array}{l}
\\
\frac{0.125}{r \cdot \left(s \cdot \pi\right)}
\end{array}
Initial program 99.7%
Simplified96.2%
Taylor expanded in s around inf
+-lowering-+.f32N/A
+-lowering-+.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
/-lowering-/.f32N/A
associate-*r/N/A
/-lowering-/.f32N/A
*-commutativeN/A
unpow2N/A
associate-*l*N/A
*-commutativeN/A
*-lowering-*.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
unpow2N/A
*-lowering-*.f329.5%
Simplified9.5%
Taylor expanded in r around inf
associate-*r/N/A
/-lowering-/.f32N/A
*-commutativeN/A
unpow2N/A
associate-*l*N/A
*-commutativeN/A
*-lowering-*.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
unpow2N/A
*-lowering-*.f325.6%
Simplified5.6%
Taylor expanded in r around 0
/-lowering-/.f32N/A
*-commutativeN/A
*-lowering-*.f326.6%
Simplified6.6%
Taylor expanded in s around 0
/-lowering-/.f32N/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
PI-lowering-PI.f326.6%
Simplified6.6%
herbie shell --seed 2024158
(FPCore (s r)
:name "Disney BSSRDF, PDF of scattering profile"
:precision binary32
:pre (and (and (<= 0.0 s) (<= s 256.0)) (and (< 1e-6 r) (< r 1000000.0)))
(+ (/ (* 0.25 (exp (/ (- r) s))) (* (* (* 2.0 PI) s) r)) (/ (* 0.75 (exp (/ (- r) (* 3.0 s)))) (* (* (* 6.0 PI) s) r))))