
(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 15 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 (exp (/ r (* s -3.0)))) (* (* s PI) (* r 6.0)))))
float code(float s, float r) {
return (0.125f / ((r * (s * ((float) M_PI))) * expf((r / s)))) + ((0.75f * expf((r / (s * -3.0f)))) / ((s * ((float) M_PI)) * (r * 6.0f)));
}
function code(s, r) return Float32(Float32(Float32(0.125) / Float32(Float32(r * Float32(s * Float32(pi))) * exp(Float32(r / s)))) + Float32(Float32(Float32(0.75) * exp(Float32(r / Float32(s * Float32(-3.0))))) / Float32(Float32(s * Float32(pi)) * Float32(r * Float32(6.0))))) 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))))) / ((s * single(pi)) * (r * single(6.0)))); end
\begin{array}{l}
\\
\frac{0.125}{\left(r \cdot \left(s \cdot \pi\right)\right) \cdot e^{\frac{r}{s}}} + \frac{0.75 \cdot e^{\frac{r}{s \cdot -3}}}{\left(s \cdot \pi\right) \cdot \left(r \cdot 6\right)}
\end{array}
Initial program 99.6%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f3299.7
Applied rewrites99.7%
lift-/.f32N/A
lift-*.f32N/A
lift-*.f32N/A
times-fracN/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
lift-*.f32N/A
associate-/r*N/A
metadata-evalN/A
times-fracN/A
Applied rewrites99.7%
lift-/.f32N/A
lift-neg.f32N/A
lift-*.f32N/A
metadata-evalN/A
distribute-lft-neg-inN/A
*-commutativeN/A
frac-2negN/A
lower-/.f32N/A
lower-*.f3299.7
Applied rewrites99.7%
lift-/.f32N/A
lift-*.f32N/A
*-commutativeN/A
lift-neg.f32N/A
lift-/.f32N/A
distribute-frac-negN/A
lift-/.f32N/A
lift-neg.f32N/A
associate-*l/N/A
lift-exp.f32N/A
lift-neg.f32N/A
lift-/.f32N/A
distribute-frac-negN/A
lift-/.f32N/A
exp-negN/A
frac-timesN/A
metadata-evalN/A
lower-/.f32N/A
Applied rewrites99.7%
Final simplification99.7%
(FPCore (s r) :precision binary32 (fma (/ (exp (/ r (* s -3.0))) (* PI (* 6.0 (* r s)))) 0.75 (/ 0.125 (* (* r (* s PI)) (exp (/ r s))))))
float code(float s, float r) {
return fmaf((expf((r / (s * -3.0f))) / (((float) M_PI) * (6.0f * (r * s)))), 0.75f, (0.125f / ((r * (s * ((float) M_PI))) * expf((r / s)))));
}
function code(s, r) return fma(Float32(exp(Float32(r / Float32(s * Float32(-3.0)))) / Float32(Float32(pi) * Float32(Float32(6.0) * Float32(r * s)))), Float32(0.75), Float32(Float32(0.125) / Float32(Float32(r * Float32(s * Float32(pi))) * exp(Float32(r / s))))) end
\begin{array}{l}
\\
\mathsf{fma}\left(\frac{e^{\frac{r}{s \cdot -3}}}{\pi \cdot \left(6 \cdot \left(r \cdot s\right)\right)}, 0.75, \frac{0.125}{\left(r \cdot \left(s \cdot \pi\right)\right) \cdot e^{\frac{r}{s}}}\right)
\end{array}
Initial program 99.6%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f3299.7
Applied rewrites99.7%
lift-/.f32N/A
lift-*.f32N/A
lift-*.f32N/A
times-fracN/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
lift-*.f32N/A
associate-/r*N/A
metadata-evalN/A
times-fracN/A
Applied rewrites99.7%
lift-/.f32N/A
lift-neg.f32N/A
lift-*.f32N/A
metadata-evalN/A
distribute-lft-neg-inN/A
*-commutativeN/A
frac-2negN/A
lower-/.f32N/A
lower-*.f3299.7
Applied rewrites99.7%
Applied rewrites99.7%
Final simplification99.7%
(FPCore (s r) :precision binary32 (* (/ 0.125 (* s PI)) (+ (/ (exp (/ r (* s -3.0))) r) (/ (exp (- (/ r s))) r))))
float code(float s, float r) {
return (0.125f / (s * ((float) M_PI))) * ((expf((r / (s * -3.0f))) / r) + (expf(-(r / s)) / r));
}
function code(s, r) return Float32(Float32(Float32(0.125) / Float32(s * Float32(pi))) * Float32(Float32(exp(Float32(r / Float32(s * Float32(-3.0)))) / r) + Float32(exp(Float32(-Float32(r / s))) / r))) end
function tmp = code(s, r) tmp = (single(0.125) / (s * single(pi))) * ((exp((r / (s * single(-3.0)))) / r) + (exp(-(r / s)) / r)); end
\begin{array}{l}
\\
\frac{0.125}{s \cdot \pi} \cdot \left(\frac{e^{\frac{r}{s \cdot -3}}}{r} + \frac{e^{-\frac{r}{s}}}{r}\right)
\end{array}
Initial program 99.6%
Applied rewrites99.6%
Final simplification99.6%
(FPCore (s r)
:precision binary32
(+
(/ (* (exp (- (/ r s))) 0.25) (* r (* s (* PI 2.0))))
(/
(fma
r
(/ 0.006944444444444444 (* PI (* s s)))
(+ (/ 0.125 (* r PI)) (/ -0.041666666666666664 (* s PI))))
s)))
float code(float s, float r) {
return ((expf(-(r / s)) * 0.25f) / (r * (s * (((float) M_PI) * 2.0f)))) + (fmaf(r, (0.006944444444444444f / (((float) M_PI) * (s * s))), ((0.125f / (r * ((float) M_PI))) + (-0.041666666666666664f / (s * ((float) M_PI))))) / s);
}
function code(s, r) return Float32(Float32(Float32(exp(Float32(-Float32(r / s))) * Float32(0.25)) / Float32(r * Float32(s * Float32(Float32(pi) * Float32(2.0))))) + Float32(fma(r, Float32(Float32(0.006944444444444444) / Float32(Float32(pi) * Float32(s * s))), Float32(Float32(Float32(0.125) / Float32(r * Float32(pi))) + Float32(Float32(-0.041666666666666664) / Float32(s * Float32(pi))))) / s)) end
\begin{array}{l}
\\
\frac{e^{-\frac{r}{s}} \cdot 0.25}{r \cdot \left(s \cdot \left(\pi \cdot 2\right)\right)} + \frac{\mathsf{fma}\left(r, \frac{0.006944444444444444}{\pi \cdot \left(s \cdot s\right)}, \frac{0.125}{r \cdot \pi} + \frac{-0.041666666666666664}{s \cdot \pi}\right)}{s}
\end{array}
Initial program 99.6%
Taylor expanded in r around 0
lower-/.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f329.0
Applied rewrites9.0%
Taylor expanded in s around inf
Applied rewrites10.0%
Final simplification10.0%
(FPCore (s r)
:precision binary32
(+
(/ (* 0.125 (exp (- (/ r s)))) (* r (* s PI)))
(/
(+
(/ 0.125 (* r PI))
(fma
(/ r (* s (* s PI)))
0.006944444444444444
(/ -0.041666666666666664 (* s PI))))
s)))
float code(float s, float r) {
return ((0.125f * expf(-(r / s))) / (r * (s * ((float) M_PI)))) + (((0.125f / (r * ((float) M_PI))) + fmaf((r / (s * (s * ((float) M_PI)))), 0.006944444444444444f, (-0.041666666666666664f / (s * ((float) M_PI))))) / s);
}
function code(s, r) return Float32(Float32(Float32(Float32(0.125) * exp(Float32(-Float32(r / s)))) / Float32(r * Float32(s * Float32(pi)))) + Float32(Float32(Float32(Float32(0.125) / Float32(r * Float32(pi))) + fma(Float32(r / Float32(s * Float32(s * Float32(pi)))), Float32(0.006944444444444444), Float32(Float32(-0.041666666666666664) / Float32(s * Float32(pi))))) / s)) end
\begin{array}{l}
\\
\frac{0.125 \cdot e^{-\frac{r}{s}}}{r \cdot \left(s \cdot \pi\right)} + \frac{\frac{0.125}{r \cdot \pi} + \mathsf{fma}\left(\frac{r}{s \cdot \left(s \cdot \pi\right)}, 0.006944444444444444, \frac{-0.041666666666666664}{s \cdot \pi}\right)}{s}
\end{array}
Initial program 99.6%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f3299.7
Applied rewrites99.7%
lift-/.f32N/A
lift-*.f32N/A
lift-*.f32N/A
times-fracN/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
lift-*.f32N/A
associate-/r*N/A
metadata-evalN/A
times-fracN/A
Applied rewrites99.7%
Taylor expanded in s around inf
Applied rewrites10.0%
Final simplification10.0%
(FPCore (s r) :precision binary32 (fma (+ (/ 0.75 r) (/ (fma (/ r s) 0.041666666666666664 -0.25) s)) (/ 0.16666666666666666 (* s PI)) (* (exp (- (/ r s))) (/ 0.125 (* PI (* r s))))))
float code(float s, float r) {
return fmaf(((0.75f / r) + (fmaf((r / s), 0.041666666666666664f, -0.25f) / s)), (0.16666666666666666f / (s * ((float) M_PI))), (expf(-(r / s)) * (0.125f / (((float) M_PI) * (r * s)))));
}
function code(s, r) return fma(Float32(Float32(Float32(0.75) / r) + Float32(fma(Float32(r / s), Float32(0.041666666666666664), Float32(-0.25)) / s)), Float32(Float32(0.16666666666666666) / Float32(s * Float32(pi))), Float32(exp(Float32(-Float32(r / s))) * Float32(Float32(0.125) / Float32(Float32(pi) * Float32(r * s))))) end
\begin{array}{l}
\\
\mathsf{fma}\left(\frac{0.75}{r} + \frac{\mathsf{fma}\left(\frac{r}{s}, 0.041666666666666664, -0.25\right)}{s}, \frac{0.16666666666666666}{s \cdot \pi}, e^{-\frac{r}{s}} \cdot \frac{0.125}{\pi \cdot \left(r \cdot s\right)}\right)
\end{array}
Initial program 99.6%
Applied rewrites98.1%
Taylor expanded in s around -inf
+-commutativeN/A
lower-+.f32N/A
associate-*r/N/A
metadata-evalN/A
lower-/.f32N/A
associate-*r/N/A
lower-/.f32N/A
+-commutativeN/A
distribute-rgt-inN/A
*-commutativeN/A
associate-*l*N/A
metadata-evalN/A
metadata-evalN/A
lower-fma.f32N/A
lower-/.f329.9
Applied rewrites9.9%
Final simplification9.9%
(FPCore (s r)
:precision binary32
(/
(fma
(/ 0.25 r)
(/ 1.0 PI)
(fma
(/ r (* s (* s PI)))
0.06944444444444445
(/ -0.16666666666666666 (* s PI))))
s))
float code(float s, float r) {
return fmaf((0.25f / r), (1.0f / ((float) M_PI)), fmaf((r / (s * (s * ((float) M_PI)))), 0.06944444444444445f, (-0.16666666666666666f / (s * ((float) M_PI))))) / s;
}
function code(s, r) return Float32(fma(Float32(Float32(0.25) / r), Float32(Float32(1.0) / Float32(pi)), fma(Float32(r / Float32(s * Float32(s * Float32(pi)))), Float32(0.06944444444444445), Float32(Float32(-0.16666666666666666) / Float32(s * Float32(pi))))) / s) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(\frac{0.25}{r}, \frac{1}{\pi}, \mathsf{fma}\left(\frac{r}{s \cdot \left(s \cdot \pi\right)}, 0.06944444444444445, \frac{-0.16666666666666666}{s \cdot \pi}\right)\right)}{s}
\end{array}
Initial program 99.6%
Taylor expanded in r around 0
lower-/.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f328.5
Applied rewrites8.5%
Taylor expanded in s around inf
lower-/.f32N/A
Applied rewrites9.4%
Applied rewrites9.5%
(FPCore (s r)
:precision binary32
(/
(fma
r
(/
(fma 0.06944444444444445 (/ r (* s PI)) (/ -0.16666666666666666 PI))
(* s s))
(/ 0.25 (* s PI)))
r))
float code(float s, float r) {
return fmaf(r, (fmaf(0.06944444444444445f, (r / (s * ((float) M_PI))), (-0.16666666666666666f / ((float) M_PI))) / (s * s)), (0.25f / (s * ((float) M_PI)))) / r;
}
function code(s, r) return Float32(fma(r, Float32(fma(Float32(0.06944444444444445), Float32(r / Float32(s * Float32(pi))), Float32(Float32(-0.16666666666666666) / Float32(pi))) / Float32(s * s)), Float32(Float32(0.25) / Float32(s * Float32(pi)))) / r) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(r, \frac{\mathsf{fma}\left(0.06944444444444445, \frac{r}{s \cdot \pi}, \frac{-0.16666666666666666}{\pi}\right)}{s \cdot s}, \frac{0.25}{s \cdot \pi}\right)}{r}
\end{array}
Initial program 99.6%
Taylor expanded in r around 0
Applied rewrites9.5%
(FPCore (s r)
:precision binary32
(/
(+
(/ (/ 0.25 r) PI)
(fma
r
(/ 0.06944444444444445 (* s (* s PI)))
(/ -0.16666666666666666 (* s PI))))
s))
float code(float s, float r) {
return (((0.25f / r) / ((float) M_PI)) + fmaf(r, (0.06944444444444445f / (s * (s * ((float) M_PI)))), (-0.16666666666666666f / (s * ((float) M_PI))))) / s;
}
function code(s, r) return Float32(Float32(Float32(Float32(Float32(0.25) / r) / Float32(pi)) + fma(r, Float32(Float32(0.06944444444444445) / Float32(s * Float32(s * Float32(pi)))), Float32(Float32(-0.16666666666666666) / Float32(s * Float32(pi))))) / s) end
\begin{array}{l}
\\
\frac{\frac{\frac{0.25}{r}}{\pi} + \mathsf{fma}\left(r, \frac{0.06944444444444445}{s \cdot \left(s \cdot \pi\right)}, \frac{-0.16666666666666666}{s \cdot \pi}\right)}{s}
\end{array}
Initial program 99.6%
lift-*.f32N/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
associate-*r*N/A
lower-*.f32N/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f3299.7
Applied rewrites99.7%
lift-/.f32N/A
lift-*.f32N/A
lift-*.f32N/A
times-fracN/A
*-commutativeN/A
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
*-commutativeN/A
lift-*.f32N/A
associate-/r*N/A
metadata-evalN/A
times-fracN/A
Applied rewrites99.7%
Taylor expanded in s around inf
Applied rewrites9.4%
Applied rewrites9.4%
(FPCore (s r) :precision binary32 (+ (/ (fma 0.06944444444444445 (/ r (* s PI)) (/ -0.16666666666666666 PI)) (* s s)) (/ 0.25 (* r (* s PI)))))
float code(float s, float r) {
return (fmaf(0.06944444444444445f, (r / (s * ((float) M_PI))), (-0.16666666666666666f / ((float) M_PI))) / (s * s)) + (0.25f / (r * (s * ((float) M_PI))));
}
function code(s, r) return Float32(Float32(fma(Float32(0.06944444444444445), Float32(r / Float32(s * Float32(pi))), Float32(Float32(-0.16666666666666666) / Float32(pi))) / Float32(s * s)) + Float32(Float32(0.25) / Float32(r * Float32(s * Float32(pi))))) end
\begin{array}{l}
\\
\frac{\mathsf{fma}\left(0.06944444444444445, \frac{r}{s \cdot \pi}, \frac{-0.16666666666666666}{\pi}\right)}{s \cdot s} + \frac{0.25}{r \cdot \left(s \cdot \pi\right)}
\end{array}
Initial program 99.6%
Taylor expanded in s around inf
Applied rewrites9.4%
(FPCore (s r) :precision binary32 (/ 0.25 (* r (* (sqrt PI) (* s (sqrt PI))))))
float code(float s, float r) {
return 0.25f / (r * (sqrtf(((float) M_PI)) * (s * sqrtf(((float) M_PI)))));
}
function code(s, r) return Float32(Float32(0.25) / Float32(r * Float32(sqrt(Float32(pi)) * Float32(s * sqrt(Float32(pi)))))) end
function tmp = code(s, r) tmp = single(0.25) / (r * (sqrt(single(pi)) * (s * sqrt(single(pi))))); end
\begin{array}{l}
\\
\frac{0.25}{r \cdot \left(\sqrt{\pi} \cdot \left(s \cdot \sqrt{\pi}\right)\right)}
\end{array}
Initial program 99.6%
Taylor expanded in r around 0
lower-/.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f328.5
Applied rewrites8.5%
Applied rewrites8.5%
Final simplification8.5%
(FPCore (s r) :precision binary32 (/ 1.0 (/ s (/ 0.25 (* r PI)))))
float code(float s, float r) {
return 1.0f / (s / (0.25f / (r * ((float) M_PI))));
}
function code(s, r) return Float32(Float32(1.0) / Float32(s / Float32(Float32(0.25) / Float32(r * Float32(pi))))) end
function tmp = code(s, r) tmp = single(1.0) / (s / (single(0.25) / (r * single(pi)))); end
\begin{array}{l}
\\
\frac{1}{\frac{s}{\frac{0.25}{r \cdot \pi}}}
\end{array}
Initial program 99.6%
Taylor expanded in r around 0
lower-/.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f328.5
Applied rewrites8.5%
Applied rewrites8.5%
Applied rewrites8.5%
(FPCore (s r) :precision binary32 (* (/ 0.25 (* r PI)) (/ 1.0 s)))
float code(float s, float r) {
return (0.25f / (r * ((float) M_PI))) * (1.0f / s);
}
function code(s, r) return Float32(Float32(Float32(0.25) / Float32(r * Float32(pi))) * Float32(Float32(1.0) / s)) end
function tmp = code(s, r) tmp = (single(0.25) / (r * single(pi))) * (single(1.0) / s); end
\begin{array}{l}
\\
\frac{0.25}{r \cdot \pi} \cdot \frac{1}{s}
\end{array}
Initial program 99.6%
Taylor expanded in r around 0
lower-/.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f328.5
Applied rewrites8.5%
Applied rewrites8.5%
Applied rewrites8.5%
(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 99.6%
Taylor expanded in r around 0
lower-/.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f328.5
Applied rewrites8.5%
Applied rewrites8.5%
Applied rewrites8.5%
(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%
Taylor expanded in r around 0
lower-/.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f328.5
Applied rewrites8.5%
herbie shell --seed 2024219
(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))))