
(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 14 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 (+ (/ (* 0.25 (exp (/ (- r) s))) (* (* (* 2.0 PI) s) r)) (/ (* 0.75 (exp (/ (- r) (* 3.0 s)))) (* (* PI 6.0) (* 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)))) / ((((float) M_PI) * 6.0f) * (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(pi) * Float32(6.0)) * Float32(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(pi) * single(6.0)) * (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(\pi \cdot 6\right) \cdot \left(s \cdot r\right)}
\end{array}
Initial program 99.6%
add-exp-log99.4%
*-commutative99.4%
associate-*r*99.4%
*-commutative99.4%
*-commutative99.4%
associate-*r*99.4%
Applied egg-rr99.4%
rem-exp-log99.6%
associate-*l*99.6%
associate-*r*99.6%
*-commutative99.6%
*-commutative99.6%
*-commutative99.6%
associate-*l*99.6%
*-commutative99.6%
Applied egg-rr99.6%
(FPCore (s r) :precision binary32 (+ (/ (* 0.25 (exp (/ (- r) s))) (* (* (* 2.0 PI) s) r)) (/ (* 0.75 (exp (* -0.3333333333333333 (/ r s)))) (* (* PI 6.0) (* s r)))))
float code(float s, float r) {
return ((0.25f * expf((-r / s))) / (((2.0f * ((float) M_PI)) * s) * r)) + ((0.75f * expf((-0.3333333333333333f * (r / s)))) / ((((float) M_PI) * 6.0f) * (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(-0.3333333333333333) * Float32(r / s)))) / Float32(Float32(Float32(pi) * Float32(6.0)) * Float32(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((single(-0.3333333333333333) * (r / s)))) / ((single(pi) * single(6.0)) * (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^{-0.3333333333333333 \cdot \frac{r}{s}}}{\left(\pi \cdot 6\right) \cdot \left(s \cdot r\right)}
\end{array}
Initial program 99.6%
add-exp-log99.4%
*-commutative99.4%
associate-*r*99.4%
*-commutative99.4%
*-commutative99.4%
associate-*r*99.4%
Applied egg-rr99.4%
rem-exp-log99.6%
associate-*l*99.6%
associate-*r*99.6%
*-commutative99.6%
*-commutative99.6%
*-commutative99.6%
associate-*l*99.6%
*-commutative99.6%
Applied egg-rr99.6%
Taylor expanded in r around 0 99.6%
(FPCore (s r) :precision binary32 (+ (/ (* 0.25 (exp (/ (- r) s))) (* (* (* 2.0 PI) s) r)) (/ (* 0.75 (exp (* (/ r s) -0.3333333333333333))) (* (* (* 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 / s) * -0.3333333333333333f))) / (((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 / s) * Float32(-0.3333333333333333)))) / 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 / s) * single(-0.3333333333333333)))) / (((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}{s} \cdot -0.3333333333333333}}{\left(\left(6 \cdot \pi\right) \cdot s\right) \cdot r}
\end{array}
Initial program 99.6%
neg-mul-199.6%
times-frac99.6%
metadata-eval99.6%
*-commutative99.6%
Applied egg-rr99.6%
(FPCore (s r) :precision binary32 (+ (* (/ 0.125 (* s PI)) (/ (exp (- (/ r s))) r)) (* 0.75 (/ (exp (/ (- r) (* s 3.0))) (* r (* 6.0 (* PI s)))))))
float code(float s, float r) {
return ((0.125f / (s * ((float) M_PI))) * (expf(-(r / s)) / r)) + (0.75f * (expf((-r / (s * 3.0f))) / (r * (6.0f * (((float) M_PI) * s)))));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.125) / Float32(s * Float32(pi))) * Float32(exp(Float32(-Float32(r / s))) / r)) + Float32(Float32(0.75) * Float32(exp(Float32(Float32(-r) / Float32(s * Float32(3.0)))) / Float32(r * Float32(Float32(6.0) * Float32(Float32(pi) * s)))))) end
function tmp = code(s, r) tmp = ((single(0.125) / (s * single(pi))) * (exp(-(r / s)) / r)) + (single(0.75) * (exp((-r / (s * single(3.0)))) / (r * (single(6.0) * (single(pi) * s))))); end
\begin{array}{l}
\\
\frac{0.125}{s \cdot \pi} \cdot \frac{e^{-\frac{r}{s}}}{r} + 0.75 \cdot \frac{e^{\frac{-r}{s \cdot 3}}}{r \cdot \left(6 \cdot \left(\pi \cdot s\right)\right)}
\end{array}
Initial program 99.6%
times-frac99.6%
*-commutative99.6%
distribute-frac-neg99.6%
associate-/l*99.6%
*-commutative99.6%
*-commutative99.6%
associate-*l*99.6%
Simplified99.6%
Taylor expanded in s around 0 99.6%
(FPCore (s r) :precision binary32 (+ (* (/ (/ 0.125 s) PI) (/ (exp (- (/ r s))) r)) (* 0.75 (/ (exp (/ (- r) (* s 3.0))) (* 6.0 (* r (* s PI)))))))
float code(float s, float r) {
return (((0.125f / s) / ((float) M_PI)) * (expf(-(r / s)) / r)) + (0.75f * (expf((-r / (s * 3.0f))) / (6.0f * (r * (s * ((float) M_PI))))));
}
function code(s, r) return Float32(Float32(Float32(Float32(Float32(0.125) / s) / Float32(pi)) * Float32(exp(Float32(-Float32(r / s))) / r)) + Float32(Float32(0.75) * Float32(exp(Float32(Float32(-r) / Float32(s * Float32(3.0)))) / Float32(Float32(6.0) * Float32(r * Float32(s * Float32(pi))))))) end
function tmp = code(s, r) tmp = (((single(0.125) / s) / single(pi)) * (exp(-(r / s)) / r)) + (single(0.75) * (exp((-r / (s * single(3.0)))) / (single(6.0) * (r * (s * single(pi)))))); end
\begin{array}{l}
\\
\frac{\frac{0.125}{s}}{\pi} \cdot \frac{e^{-\frac{r}{s}}}{r} + 0.75 \cdot \frac{e^{\frac{-r}{s \cdot 3}}}{6 \cdot \left(r \cdot \left(s \cdot \pi\right)\right)}
\end{array}
Initial program 99.6%
times-frac99.6%
*-commutative99.6%
distribute-frac-neg99.6%
associate-/l*99.6%
*-commutative99.6%
*-commutative99.6%
associate-*l*99.6%
Simplified99.6%
*-commutative99.6%
associate-*l*99.6%
*-commutative99.6%
associate-/r*99.6%
metadata-eval99.6%
add-exp-log99.5%
Applied egg-rr99.5%
rem-exp-log99.6%
associate-/r*99.6%
Applied egg-rr99.6%
expm1-log1p-u99.6%
associate-*r*99.6%
*-commutative99.6%
Applied egg-rr99.6%
Taylor expanded in r around 0 99.6%
(FPCore (s r) :precision binary32 (+ (* (/ (/ 0.125 s) PI) (/ (exp (- (/ r s))) r)) (* 0.75 (/ (exp (/ (- r) (* s 3.0))) (* r (* 6.0 (* PI s)))))))
float code(float s, float r) {
return (((0.125f / s) / ((float) M_PI)) * (expf(-(r / s)) / r)) + (0.75f * (expf((-r / (s * 3.0f))) / (r * (6.0f * (((float) M_PI) * s)))));
}
function code(s, r) return Float32(Float32(Float32(Float32(Float32(0.125) / s) / Float32(pi)) * Float32(exp(Float32(-Float32(r / s))) / r)) + Float32(Float32(0.75) * Float32(exp(Float32(Float32(-r) / Float32(s * Float32(3.0)))) / Float32(r * Float32(Float32(6.0) * Float32(Float32(pi) * s)))))) end
function tmp = code(s, r) tmp = (((single(0.125) / s) / single(pi)) * (exp(-(r / s)) / r)) + (single(0.75) * (exp((-r / (s * single(3.0)))) / (r * (single(6.0) * (single(pi) * s))))); end
\begin{array}{l}
\\
\frac{\frac{0.125}{s}}{\pi} \cdot \frac{e^{-\frac{r}{s}}}{r} + 0.75 \cdot \frac{e^{\frac{-r}{s \cdot 3}}}{r \cdot \left(6 \cdot \left(\pi \cdot s\right)\right)}
\end{array}
Initial program 99.6%
times-frac99.6%
*-commutative99.6%
distribute-frac-neg99.6%
associate-/l*99.6%
*-commutative99.6%
*-commutative99.6%
associate-*l*99.6%
Simplified99.6%
*-commutative99.6%
associate-*l*99.6%
*-commutative99.6%
associate-/r*99.6%
metadata-eval99.6%
add-exp-log99.5%
Applied egg-rr99.5%
rem-exp-log99.6%
associate-/r*99.6%
Applied egg-rr99.6%
(FPCore (s r) :precision binary32 (* (/ 0.125 (* s PI)) (+ (/ (exp (/ r (- s))) r) (/ (exp (* -0.3333333333333333 (/ r s))) r))))
float code(float s, float r) {
return (0.125f / (s * ((float) M_PI))) * ((expf((r / -s)) / r) + (expf((-0.3333333333333333f * (r / s))) / r));
}
function code(s, r) return Float32(Float32(Float32(0.125) / Float32(s * Float32(pi))) * Float32(Float32(exp(Float32(r / Float32(-s))) / r) + Float32(exp(Float32(Float32(-0.3333333333333333) * Float32(r / s))) / r))) end
function tmp = code(s, r) tmp = (single(0.125) / (s * single(pi))) * ((exp((r / -s)) / r) + (exp((single(-0.3333333333333333) * (r / s))) / r)); end
\begin{array}{l}
\\
\frac{0.125}{s \cdot \pi} \cdot \left(\frac{e^{\frac{r}{-s}}}{r} + \frac{e^{-0.3333333333333333 \cdot \frac{r}{s}}}{r}\right)
\end{array}
Initial program 99.6%
Simplified99.3%
Taylor expanded in r around inf 99.6%
(FPCore (s r) :precision binary32 (/ 0.25 (log1p (expm1 (* r (* PI s))))))
float code(float s, float r) {
return 0.25f / log1pf(expm1f((r * (((float) M_PI) * s))));
}
function code(s, r) return Float32(Float32(0.25) / log1p(expm1(Float32(r * Float32(Float32(pi) * s))))) end
\begin{array}{l}
\\
\frac{0.25}{\mathsf{log1p}\left(\mathsf{expm1}\left(r \cdot \left(\pi \cdot s\right)\right)\right)}
\end{array}
Initial program 99.6%
Simplified99.3%
Taylor expanded in r around 0 9.8%
Taylor expanded in s around inf 9.3%
log1p-expm1-u12.6%
*-commutative12.6%
Applied egg-rr12.6%
(FPCore (s r) :precision binary32 (* (/ 0.125 (* s PI)) (+ (/ (exp (/ r (- s))) r) (/ 1.0 r))))
float code(float s, float r) {
return (0.125f / (s * ((float) M_PI))) * ((expf((r / -s)) / r) + (1.0f / r));
}
function code(s, r) return Float32(Float32(Float32(0.125) / Float32(s * Float32(pi))) * Float32(Float32(exp(Float32(r / Float32(-s))) / r) + Float32(Float32(1.0) / r))) end
function tmp = code(s, r) tmp = (single(0.125) / (s * single(pi))) * ((exp((r / -s)) / r) + (single(1.0) / r)); end
\begin{array}{l}
\\
\frac{0.125}{s \cdot \pi} \cdot \left(\frac{e^{\frac{r}{-s}}}{r} + \frac{1}{r}\right)
\end{array}
Initial program 99.6%
Simplified99.3%
Taylor expanded in r around 0 9.8%
(FPCore (s r) :precision binary32 (* 0.125 (/ (+ 1.0 (exp (* -1.0 (/ r s)))) (* r (* s PI)))))
float code(float s, float r) {
return 0.125f * ((1.0f + expf((-1.0f * (r / s)))) / (r * (s * ((float) M_PI))));
}
function code(s, r) return Float32(Float32(0.125) * Float32(Float32(Float32(1.0) + exp(Float32(Float32(-1.0) * Float32(r / s)))) / Float32(r * Float32(s * Float32(pi))))) end
function tmp = code(s, r) tmp = single(0.125) * ((single(1.0) + exp((single(-1.0) * (r / s)))) / (r * (s * single(pi)))); end
\begin{array}{l}
\\
0.125 \cdot \frac{1 + e^{-1 \cdot \frac{r}{s}}}{r \cdot \left(s \cdot \pi\right)}
\end{array}
Initial program 99.6%
Simplified99.3%
Taylor expanded in r around 0 9.8%
Taylor expanded in r around inf 9.8%
(FPCore (s r) :precision binary32 (* 0.125 (/ (+ 1.0 (/ 1.0 (exp (/ r s)))) (* r (* s PI)))))
float code(float s, float r) {
return 0.125f * ((1.0f + (1.0f / expf((r / s)))) / (r * (s * ((float) M_PI))));
}
function code(s, r) return Float32(Float32(0.125) * Float32(Float32(Float32(1.0) + Float32(Float32(1.0) / exp(Float32(r / s)))) / Float32(r * Float32(s * Float32(pi))))) end
function tmp = code(s, r) tmp = single(0.125) * ((single(1.0) + (single(1.0) / exp((r / s)))) / (r * (s * single(pi)))); end
\begin{array}{l}
\\
0.125 \cdot \frac{1 + \frac{1}{e^{\frac{r}{s}}}}{r \cdot \left(s \cdot \pi\right)}
\end{array}
Initial program 99.6%
Simplified99.3%
Taylor expanded in r around 0 9.8%
Taylor expanded in s around 0 9.8%
mul-1-neg9.8%
exp-neg9.8%
Applied egg-rr9.8%
Taylor expanded in r around inf 9.8%
(FPCore (s r) :precision binary32 (* 0.125 (/ (+ (/ 1.0 r) (/ (/ 1.0 (+ 1.0 (/ r s))) r)) (* s PI))))
float code(float s, float r) {
return 0.125f * (((1.0f / r) + ((1.0f / (1.0f + (r / s))) / r)) / (s * ((float) M_PI)));
}
function code(s, r) return Float32(Float32(0.125) * Float32(Float32(Float32(Float32(1.0) / r) + Float32(Float32(Float32(1.0) / Float32(Float32(1.0) + Float32(r / s))) / r)) / Float32(s * Float32(pi)))) end
function tmp = code(s, r) tmp = single(0.125) * (((single(1.0) / r) + ((single(1.0) / (single(1.0) + (r / s))) / r)) / (s * single(pi))); end
\begin{array}{l}
\\
0.125 \cdot \frac{\frac{1}{r} + \frac{\frac{1}{1 + \frac{r}{s}}}{r}}{s \cdot \pi}
\end{array}
Initial program 99.6%
Simplified99.3%
Taylor expanded in r around 0 9.8%
Taylor expanded in s around 0 9.8%
mul-1-neg9.8%
exp-neg9.8%
Applied egg-rr9.8%
Taylor expanded in r around 0 9.8%
(FPCore (s r) :precision binary32 (* 1.0 (/ (/ 0.25 r) (* PI s))))
float code(float s, float r) {
return 1.0f * ((0.25f / r) / (((float) M_PI) * s));
}
function code(s, r) return Float32(Float32(1.0) * Float32(Float32(Float32(0.25) / r) / Float32(Float32(pi) * s))) end
function tmp = code(s, r) tmp = single(1.0) * ((single(0.25) / r) / (single(pi) * s)); end
\begin{array}{l}
\\
1 \cdot \frac{\frac{0.25}{r}}{\pi \cdot s}
\end{array}
Initial program 99.6%
Simplified99.3%
Taylor expanded in r around 0 9.8%
Taylor expanded in s around inf 9.3%
*-un-lft-identity9.3%
associate-/r*9.3%
*-commutative9.3%
Applied egg-rr9.3%
(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 99.6%
Simplified99.3%
Taylor expanded in r around 0 9.8%
Taylor expanded in s around inf 9.3%
herbie shell --seed 2024050 -o generate:simplify
(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))))