
(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 13 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 (+ (/ 0.125 (* r (* s (* PI (exp (/ r s)))))) (/ (* 0.75 (/ 1.0 (exp (/ r (* s 3.0))))) (* (* PI 6.0) (* r s)))))
float code(float s, float r) {
return (0.125f / (r * (s * (((float) M_PI) * expf((r / s)))))) + ((0.75f * (1.0f / expf((r / (s * 3.0f))))) / ((((float) M_PI) * 6.0f) * (r * s)));
}
function code(s, r) return Float32(Float32(Float32(0.125) / Float32(r * Float32(s * Float32(Float32(pi) * exp(Float32(r / s)))))) + Float32(Float32(Float32(0.75) * Float32(Float32(1.0) / exp(Float32(r / Float32(s * Float32(3.0)))))) / Float32(Float32(Float32(pi) * Float32(6.0)) * Float32(r * s)))) end
function tmp = code(s, r) tmp = (single(0.125) / (r * (s * (single(pi) * exp((r / s)))))) + ((single(0.75) * (single(1.0) / exp((r / (s * single(3.0)))))) / ((single(pi) * single(6.0)) * (r * s))); end
\begin{array}{l}
\\
\frac{0.125}{r \cdot \left(s \cdot \left(\pi \cdot e^{\frac{r}{s}}\right)\right)} + \frac{0.75 \cdot \frac{1}{e^{\frac{r}{s \cdot 3}}}}{\left(\pi \cdot 6\right) \cdot \left(r \cdot s\right)}
\end{array}
Initial program 99.5%
Taylor expanded in r around inf 99.5%
neg-mul-199.5%
rec-exp99.5%
associate-*r/99.5%
metadata-eval99.5%
Simplified99.5%
pow199.5%
associate-*l*99.6%
*-commutative99.6%
Applied egg-rr99.6%
unpow199.6%
*-commutative99.6%
Simplified99.6%
Taylor expanded in r around inf 99.5%
distribute-frac-neg99.5%
exp-neg99.6%
*-commutative99.6%
Applied egg-rr99.6%
(FPCore (s r) :precision binary32 (+ (/ 0.125 (* r (* s (* PI (exp (/ r s)))))) (/ (* 0.75 (exp (/ r (* s (- 3.0))))) (* (* PI 6.0) (* r s)))))
float code(float s, float r) {
return (0.125f / (r * (s * (((float) M_PI) * expf((r / s)))))) + ((0.75f * expf((r / (s * -3.0f)))) / ((((float) M_PI) * 6.0f) * (r * s)));
}
function code(s, r) return Float32(Float32(Float32(0.125) / Float32(r * Float32(s * Float32(Float32(pi) * exp(Float32(r / s)))))) + Float32(Float32(Float32(0.75) * exp(Float32(r / Float32(s * Float32(-Float32(3.0)))))) / Float32(Float32(Float32(pi) * Float32(6.0)) * Float32(r * s)))) end
function tmp = code(s, r) tmp = (single(0.125) / (r * (s * (single(pi) * exp((r / s)))))) + ((single(0.75) * exp((r / (s * -single(3.0))))) / ((single(pi) * single(6.0)) * (r * s))); end
\begin{array}{l}
\\
\frac{0.125}{r \cdot \left(s \cdot \left(\pi \cdot e^{\frac{r}{s}}\right)\right)} + \frac{0.75 \cdot e^{\frac{r}{s \cdot \left(-3\right)}}}{\left(\pi \cdot 6\right) \cdot \left(r \cdot s\right)}
\end{array}
Initial program 99.5%
Taylor expanded in r around inf 99.5%
neg-mul-199.5%
rec-exp99.5%
associate-*r/99.5%
metadata-eval99.5%
Simplified99.5%
pow199.5%
associate-*l*99.6%
*-commutative99.6%
Applied egg-rr99.6%
unpow199.6%
*-commutative99.6%
Simplified99.6%
Taylor expanded in r around inf 99.5%
Final simplification99.5%
(FPCore (s r) :precision binary32 (+ (/ 0.125 (* r (* s (* PI (exp (/ r s)))))) (/ (* 0.75 (exp (* r (/ -0.3333333333333333 s)))) (* (* PI 6.0) (* r s)))))
float code(float s, float r) {
return (0.125f / (r * (s * (((float) M_PI) * expf((r / s)))))) + ((0.75f * expf((r * (-0.3333333333333333f / s)))) / ((((float) M_PI) * 6.0f) * (r * s)));
}
function code(s, r) return Float32(Float32(Float32(0.125) / Float32(r * Float32(s * Float32(Float32(pi) * exp(Float32(r / s)))))) + Float32(Float32(Float32(0.75) * exp(Float32(r * Float32(Float32(-0.3333333333333333) / s)))) / Float32(Float32(Float32(pi) * Float32(6.0)) * Float32(r * s)))) end
function tmp = code(s, r) tmp = (single(0.125) / (r * (s * (single(pi) * exp((r / s)))))) + ((single(0.75) * exp((r * (single(-0.3333333333333333) / s)))) / ((single(pi) * single(6.0)) * (r * s))); end
\begin{array}{l}
\\
\frac{0.125}{r \cdot \left(s \cdot \left(\pi \cdot e^{\frac{r}{s}}\right)\right)} + \frac{0.75 \cdot e^{r \cdot \frac{-0.3333333333333333}{s}}}{\left(\pi \cdot 6\right) \cdot \left(r \cdot s\right)}
\end{array}
Initial program 99.5%
Taylor expanded in r around inf 99.5%
neg-mul-199.5%
rec-exp99.5%
associate-*r/99.5%
metadata-eval99.5%
Simplified99.5%
pow199.5%
associate-*l*99.6%
*-commutative99.6%
Applied egg-rr99.6%
unpow199.6%
*-commutative99.6%
Simplified99.6%
Taylor expanded in r around inf 99.5%
Taylor expanded in r around 0 99.4%
associate-*r/99.4%
*-commutative99.4%
associate-*r/99.5%
Simplified99.5%
(FPCore (s r) :precision binary32 (* 0.125 (/ (+ (exp (* r (/ -0.3333333333333333 s))) (exp (/ r (- s)))) (* r (* s PI)))))
float code(float s, float r) {
return 0.125f * ((expf((r * (-0.3333333333333333f / s))) + expf((r / -s))) / (r * (s * ((float) M_PI))));
}
function code(s, r) return Float32(Float32(0.125) * Float32(Float32(exp(Float32(r * Float32(Float32(-0.3333333333333333) / s))) + exp(Float32(r / Float32(-s)))) / Float32(r * Float32(s * Float32(pi))))) end
function tmp = code(s, r) tmp = single(0.125) * ((exp((r * (single(-0.3333333333333333) / s))) + exp((r / -s))) / (r * (s * single(pi)))); end
\begin{array}{l}
\\
0.125 \cdot \frac{e^{r \cdot \frac{-0.3333333333333333}{s}} + e^{\frac{r}{-s}}}{r \cdot \left(s \cdot \pi\right)}
\end{array}
Initial program 99.5%
Simplified99.0%
Taylor expanded in r around inf 99.4%
neg-mul-199.4%
distribute-neg-frac299.4%
*-commutative99.4%
associate-*l/99.4%
associate-/l*99.5%
Simplified99.5%
Final simplification99.5%
(FPCore (s r) :precision binary32 (+ (/ (* 0.75 (exp (/ r (* s (- 3.0))))) (* (* PI 6.0) (* r s))) (/ 0.125 (* r (+ (* s PI) (* r (+ PI (* 0.5 (/ (* r PI) s)))))))))
float code(float s, float r) {
return ((0.75f * expf((r / (s * -3.0f)))) / ((((float) M_PI) * 6.0f) * (r * s))) + (0.125f / (r * ((s * ((float) M_PI)) + (r * (((float) M_PI) + (0.5f * ((r * ((float) M_PI)) / s)))))));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.75) * exp(Float32(r / Float32(s * Float32(-Float32(3.0)))))) / Float32(Float32(Float32(pi) * Float32(6.0)) * Float32(r * s))) + Float32(Float32(0.125) / Float32(r * Float32(Float32(s * Float32(pi)) + Float32(r * Float32(Float32(pi) + Float32(Float32(0.5) * Float32(Float32(r * Float32(pi)) / s)))))))) end
function tmp = code(s, r) tmp = ((single(0.75) * exp((r / (s * -single(3.0))))) / ((single(pi) * single(6.0)) * (r * s))) + (single(0.125) / (r * ((s * single(pi)) + (r * (single(pi) + (single(0.5) * ((r * single(pi)) / s))))))); end
\begin{array}{l}
\\
\frac{0.75 \cdot e^{\frac{r}{s \cdot \left(-3\right)}}}{\left(\pi \cdot 6\right) \cdot \left(r \cdot s\right)} + \frac{0.125}{r \cdot \left(s \cdot \pi + r \cdot \left(\pi + 0.5 \cdot \frac{r \cdot \pi}{s}\right)\right)}
\end{array}
Initial program 99.5%
Taylor expanded in r around inf 99.5%
neg-mul-199.5%
rec-exp99.5%
associate-*r/99.5%
metadata-eval99.5%
Simplified99.5%
pow199.5%
associate-*l*99.6%
*-commutative99.6%
Applied egg-rr99.6%
unpow199.6%
*-commutative99.6%
Simplified99.6%
Taylor expanded in r around inf 99.5%
Taylor expanded in r around 0 30.0%
Final simplification30.0%
(FPCore (s r) :precision binary32 (+ (/ (* 0.75 (exp (/ r (* s (- 3.0))))) (* (* PI 6.0) (* r s))) (/ 0.125 (* r (* s (+ PI (* r (/ PI s))))))))
float code(float s, float r) {
return ((0.75f * expf((r / (s * -3.0f)))) / ((((float) M_PI) * 6.0f) * (r * s))) + (0.125f / (r * (s * (((float) M_PI) + (r * (((float) M_PI) / s))))));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.75) * exp(Float32(r / Float32(s * Float32(-Float32(3.0)))))) / Float32(Float32(Float32(pi) * Float32(6.0)) * Float32(r * s))) + Float32(Float32(0.125) / Float32(r * Float32(s * Float32(Float32(pi) + Float32(r * Float32(Float32(pi) / s))))))) end
function tmp = code(s, r) tmp = ((single(0.75) * exp((r / (s * -single(3.0))))) / ((single(pi) * single(6.0)) * (r * s))) + (single(0.125) / (r * (s * (single(pi) + (r * (single(pi) / s)))))); end
\begin{array}{l}
\\
\frac{0.75 \cdot e^{\frac{r}{s \cdot \left(-3\right)}}}{\left(\pi \cdot 6\right) \cdot \left(r \cdot s\right)} + \frac{0.125}{r \cdot \left(s \cdot \left(\pi + r \cdot \frac{\pi}{s}\right)\right)}
\end{array}
Initial program 99.5%
Taylor expanded in r around inf 99.5%
neg-mul-199.5%
rec-exp99.5%
associate-*r/99.5%
metadata-eval99.5%
Simplified99.5%
pow199.5%
associate-*l*99.6%
*-commutative99.6%
Applied egg-rr99.6%
unpow199.6%
*-commutative99.6%
Simplified99.6%
Taylor expanded in r around inf 99.5%
Taylor expanded in s around inf 19.3%
associate-/l*19.3%
Simplified19.3%
Final simplification19.3%
(FPCore (s r) :precision binary32 (/ (* -0.125 (- (/ -1.0 (+ (/ r s) 1.0)) (exp (* r (/ -0.3333333333333333 s))))) (* r (* s PI))))
float code(float s, float r) {
return (-0.125f * ((-1.0f / ((r / s) + 1.0f)) - expf((r * (-0.3333333333333333f / s))))) / (r * (s * ((float) M_PI)));
}
function code(s, r) return Float32(Float32(Float32(-0.125) * Float32(Float32(Float32(-1.0) / Float32(Float32(r / s) + Float32(1.0))) - exp(Float32(r * Float32(Float32(-0.3333333333333333) / s))))) / Float32(r * Float32(s * Float32(pi)))) end
function tmp = code(s, r) tmp = (single(-0.125) * ((single(-1.0) / ((r / s) + single(1.0))) - exp((r * (single(-0.3333333333333333) / s))))) / (r * (s * single(pi))); end
\begin{array}{l}
\\
\frac{-0.125 \cdot \left(\frac{-1}{\frac{r}{s} + 1} - e^{r \cdot \frac{-0.3333333333333333}{s}}\right)}{r \cdot \left(s \cdot \pi\right)}
\end{array}
Initial program 99.5%
Simplified99.0%
Taylor expanded in r around -inf 99.4%
associate-*r/99.4%
Simplified99.5%
Taylor expanded in r around 0 18.6%
Final simplification18.6%
(FPCore (s r)
:precision binary32
(/
(+
(/
(+
(* 0.125 (/ (+ (* 0.05555555555555555 (/ r PI)) (* 0.5 (/ r PI))) s))
(* 0.16666666666666666 (/ -1.0 PI)))
s)
(* 0.25 (/ 1.0 (* r PI))))
s))
float code(float s, float r) {
return ((((0.125f * (((0.05555555555555555f * (r / ((float) M_PI))) + (0.5f * (r / ((float) M_PI)))) / s)) + (0.16666666666666666f * (-1.0f / ((float) M_PI)))) / s) + (0.25f * (1.0f / (r * ((float) M_PI))))) / s;
}
function code(s, r) return Float32(Float32(Float32(Float32(Float32(Float32(0.125) * Float32(Float32(Float32(Float32(0.05555555555555555) * Float32(r / Float32(pi))) + Float32(Float32(0.5) * Float32(r / Float32(pi)))) / s)) + Float32(Float32(0.16666666666666666) * Float32(Float32(-1.0) / Float32(pi)))) / s) + Float32(Float32(0.25) * Float32(Float32(1.0) / Float32(r * Float32(pi))))) / s) end
function tmp = code(s, r) tmp = ((((single(0.125) * (((single(0.05555555555555555) * (r / single(pi))) + (single(0.5) * (r / single(pi)))) / s)) + (single(0.16666666666666666) * (single(-1.0) / single(pi)))) / s) + (single(0.25) * (single(1.0) / (r * single(pi))))) / s; end
\begin{array}{l}
\\
\frac{\frac{0.125 \cdot \frac{0.05555555555555555 \cdot \frac{r}{\pi} + 0.5 \cdot \frac{r}{\pi}}{s} + 0.16666666666666666 \cdot \frac{-1}{\pi}}{s} + 0.25 \cdot \frac{1}{r \cdot \pi}}{s}
\end{array}
Initial program 99.5%
Simplified99.0%
Taylor expanded in s around -inf 13.1%
Final simplification13.1%
(FPCore (s r)
:precision binary32
(/
(-
(/ 0.25 (* r PI))
(/
(+ (/ (* (/ r PI) -0.06944444444444445) s) (/ 0.16666666666666666 PI))
s))
s))
float code(float s, float r) {
return ((0.25f / (r * ((float) M_PI))) - (((((r / ((float) M_PI)) * -0.06944444444444445f) / s) + (0.16666666666666666f / ((float) M_PI))) / s)) / s;
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) / Float32(r * Float32(pi))) - Float32(Float32(Float32(Float32(Float32(r / Float32(pi)) * Float32(-0.06944444444444445)) / s) + Float32(Float32(0.16666666666666666) / Float32(pi))) / s)) / s) end
function tmp = code(s, r) tmp = ((single(0.25) / (r * single(pi))) - (((((r / single(pi)) * single(-0.06944444444444445)) / s) + (single(0.16666666666666666) / single(pi))) / s)) / s; end
\begin{array}{l}
\\
\frac{\frac{0.25}{r \cdot \pi} - \frac{\frac{\frac{r}{\pi} \cdot -0.06944444444444445}{s} + \frac{0.16666666666666666}{\pi}}{s}}{s}
\end{array}
Initial program 99.5%
+-commutative99.5%
times-frac99.5%
fma-define99.6%
associate-*l*99.6%
associate-/r*99.5%
metadata-eval99.5%
*-commutative99.5%
neg-mul-199.5%
times-frac99.4%
metadata-eval99.4%
times-frac99.4%
Simplified99.4%
Taylor expanded in s around -inf 13.1%
mul-1-neg13.1%
Simplified13.1%
Final simplification13.1%
(FPCore (s r) :precision binary32 (/ (+ (/ 0.25 (* r PI)) (/ (- (* (/ r s) (/ 0.06944444444444445 PI)) (/ 0.16666666666666666 PI)) s)) s))
float code(float s, float r) {
return ((0.25f / (r * ((float) M_PI))) + ((((r / s) * (0.06944444444444445f / ((float) M_PI))) - (0.16666666666666666f / ((float) M_PI))) / s)) / s;
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) / Float32(r * Float32(pi))) + Float32(Float32(Float32(Float32(r / s) * Float32(Float32(0.06944444444444445) / Float32(pi))) - Float32(Float32(0.16666666666666666) / Float32(pi))) / s)) / s) end
function tmp = code(s, r) tmp = ((single(0.25) / (r * single(pi))) + ((((r / s) * (single(0.06944444444444445) / single(pi))) - (single(0.16666666666666666) / single(pi))) / s)) / s; end
\begin{array}{l}
\\
\frac{\frac{0.25}{r \cdot \pi} + \frac{\frac{r}{s} \cdot \frac{0.06944444444444445}{\pi} - \frac{0.16666666666666666}{\pi}}{s}}{s}
\end{array}
Initial program 99.5%
+-commutative99.5%
times-frac99.5%
fma-define99.6%
associate-*l*99.6%
associate-/r*99.5%
metadata-eval99.5%
*-commutative99.5%
neg-mul-199.5%
times-frac99.4%
metadata-eval99.4%
times-frac99.4%
Simplified99.4%
Taylor expanded in s around -inf 13.1%
mul-1-neg13.1%
Simplified13.1%
Taylor expanded in r around 0 13.1%
associate-*r/13.1%
*-commutative13.1%
times-frac13.1%
Simplified13.1%
Final simplification13.1%
(FPCore (s r) :precision binary32 (/ (- (/ 0.25 (* r PI)) (/ 0.16666666666666666 (* s PI))) s))
float code(float s, float r) {
return ((0.25f / (r * ((float) M_PI))) - (0.16666666666666666f / (s * ((float) M_PI)))) / s;
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) / Float32(r * Float32(pi))) - Float32(Float32(0.16666666666666666) / Float32(s * Float32(pi)))) / s) end
function tmp = code(s, r) tmp = ((single(0.25) / (r * single(pi))) - (single(0.16666666666666666) / (s * single(pi)))) / s; end
\begin{array}{l}
\\
\frac{\frac{0.25}{r \cdot \pi} - \frac{0.16666666666666666}{s \cdot \pi}}{s}
\end{array}
Initial program 99.5%
Simplified99.0%
Taylor expanded in s around inf 11.6%
associate-*r/11.6%
metadata-eval11.6%
associate-*r/11.6%
metadata-eval11.6%
Simplified11.6%
(FPCore (s r) :precision binary32 (/ (/ (/ 0.25 PI) s) r))
float code(float s, float r) {
return ((0.25f / ((float) M_PI)) / s) / r;
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) / Float32(pi)) / s) / r) end
function tmp = code(s, r) tmp = ((single(0.25) / single(pi)) / s) / r; end
\begin{array}{l}
\\
\frac{\frac{\frac{0.25}{\pi}}{s}}{r}
\end{array}
Initial program 99.5%
Simplified99.0%
add-sqr-sqrt99.0%
sqrt-unprod98.3%
pow-prod-down98.2%
prod-exp98.5%
metadata-eval98.5%
Applied egg-rr98.5%
Taylor expanded in s around inf 10.7%
associate-/r*10.7%
Simplified10.7%
Taylor expanded in r around 0 10.7%
associate-/l/10.7%
Simplified10.7%
div-inv10.7%
Applied egg-rr10.7%
associate-*r/10.7%
metadata-eval10.7%
*-commutative10.7%
associate-/r*10.7%
Simplified10.7%
(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(r * Float32(s * Float32(pi)))) end
function tmp = code(s, r) tmp = single(0.25) / (r * (s * single(pi))); end
\begin{array}{l}
\\
\frac{0.25}{r \cdot \left(s \cdot \pi\right)}
\end{array}
Initial program 99.5%
Simplified99.0%
Taylor expanded in s around inf 10.7%
herbie shell --seed 2024167
(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))))