
(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
\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}
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
\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}
(FPCore (s r)
:precision binary32
(+
(/ 0.125 (* (* (* (exp (/ r s)) s) PI) r))
(/
0.75
(*
(+ (sinh (/ (/ r s) 3.0)) (cosh (* (/ r s) 0.3333333333333333)))
(* (* (* 6.0 PI) s) r)))))float code(float s, float r) {
return (0.125f / (((expf((r / s)) * s) * ((float) M_PI)) * r)) + (0.75f / ((sinhf(((r / s) / 3.0f)) + coshf(((r / s) * 0.3333333333333333f))) * (((6.0f * ((float) M_PI)) * s) * r)));
}
function code(s, r) return Float32(Float32(Float32(0.125) / Float32(Float32(Float32(exp(Float32(r / s)) * s) * Float32(pi)) * r)) + Float32(Float32(0.75) / Float32(Float32(sinh(Float32(Float32(r / s) / Float32(3.0))) + cosh(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(0.125) / (((exp((r / s)) * s) * single(pi)) * r)) + (single(0.75) / ((sinh(((r / s) / single(3.0))) + cosh(((r / s) * single(0.3333333333333333)))) * (((single(6.0) * single(pi)) * s) * r))); end
\frac{0.125}{\left(\left(e^{\frac{r}{s}} \cdot s\right) \cdot \pi\right) \cdot r} + \frac{0.75}{\left(\sinh \left(\frac{\frac{r}{s}}{3}\right) + \cosh \left(\frac{r}{s} \cdot 0.3333333333333333\right)\right) \cdot \left(\left(\left(6 \cdot \pi\right) \cdot s\right) \cdot r\right)}
Initial program 99.6%
lift-/.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-/l*N/A
lift-exp.f32N/A
lift-/.f32N/A
lift-neg.f32N/A
distribute-frac-negN/A
exp-negN/A
frac-timesN/A
metadata-evalN/A
lower-/.f32N/A
lower-*.f32N/A
Applied rewrites99.5%
lift-exp.f32N/A
sinh-+-cosh-revN/A
+-commutativeN/A
cosh-neg-revN/A
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
mult-flipN/A
associate-*l*N/A
*-commutativeN/A
mult-flipN/A
lift-/.f32N/A
distribute-lft-neg-outN/A
metadata-evalN/A
lift-*.f32N/A
lower-+.f32N/A
lower-sinh.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
metadata-evalN/A
distribute-rgt-neg-outN/A
Applied rewrites99.5%
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
metadata-evalN/A
associate-/r*N/A
mult-flipN/A
*-commutativeN/A
associate-/r*N/A
lift-/.f32N/A
lower-/.f3299.5%
Applied rewrites99.5%
Applied rewrites99.5%
(FPCore (s r)
:precision binary32
(+
(/ (/ 0.125 (* (* (exp (/ r s)) PI) s)) r)
(/
0.75
(*
(+
(sinh (* (/ 0.3333333333333333 s) r))
(cosh (* (/ r s) 0.3333333333333333)))
(* (* (* 6.0 PI) s) r)))))float code(float s, float r) {
return ((0.125f / ((expf((r / s)) * ((float) M_PI)) * s)) / r) + (0.75f / ((sinhf(((0.3333333333333333f / s) * r)) + coshf(((r / s) * 0.3333333333333333f))) * (((6.0f * ((float) M_PI)) * s) * r)));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.125) / Float32(Float32(exp(Float32(r / s)) * Float32(pi)) * s)) / r) + Float32(Float32(0.75) / Float32(Float32(sinh(Float32(Float32(Float32(0.3333333333333333) / s) * r)) + cosh(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(0.125) / ((exp((r / s)) * single(pi)) * s)) / r) + (single(0.75) / ((sinh(((single(0.3333333333333333) / s) * r)) + cosh(((r / s) * single(0.3333333333333333)))) * (((single(6.0) * single(pi)) * s) * r))); end
\frac{\frac{0.125}{\left(e^{\frac{r}{s}} \cdot \pi\right) \cdot s}}{r} + \frac{0.75}{\left(\sinh \left(\frac{0.3333333333333333}{s} \cdot r\right) + \cosh \left(\frac{r}{s} \cdot 0.3333333333333333\right)\right) \cdot \left(\left(\left(6 \cdot \pi\right) \cdot s\right) \cdot r\right)}
Initial program 99.6%
lift-/.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-/l*N/A
lift-exp.f32N/A
lift-/.f32N/A
lift-neg.f32N/A
distribute-frac-negN/A
exp-negN/A
frac-timesN/A
metadata-evalN/A
lower-/.f32N/A
lower-*.f32N/A
Applied rewrites99.5%
lift-exp.f32N/A
sinh-+-cosh-revN/A
+-commutativeN/A
cosh-neg-revN/A
lift-*.f32N/A
*-commutativeN/A
lift-/.f32N/A
mult-flipN/A
associate-*l*N/A
*-commutativeN/A
mult-flipN/A
lift-/.f32N/A
distribute-lft-neg-outN/A
metadata-evalN/A
lift-*.f32N/A
lower-+.f32N/A
lower-sinh.f32N/A
lift-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
metadata-evalN/A
distribute-rgt-neg-outN/A
Applied rewrites99.5%
lift-/.f32N/A
lift-*.f32N/A
associate-/r*N/A
Applied rewrites99.5%
(FPCore (s r) :precision binary32 (/ (fma (* (/ 0.16666666666666666 (* PI s)) (exp (* -0.3333333333333333 (/ r s)))) 0.75 (/ 0.125 (* (* (exp (/ r s)) s) PI))) r))
float code(float s, float r) {
return fmaf(((0.16666666666666666f / (((float) M_PI) * s)) * expf((-0.3333333333333333f * (r / s)))), 0.75f, (0.125f / ((expf((r / s)) * s) * ((float) M_PI)))) / r;
}
function code(s, r) return Float32(fma(Float32(Float32(Float32(0.16666666666666666) / Float32(Float32(pi) * s)) * exp(Float32(Float32(-0.3333333333333333) * Float32(r / s)))), Float32(0.75), Float32(Float32(0.125) / Float32(Float32(exp(Float32(r / s)) * s) * Float32(pi)))) / r) end
\frac{\mathsf{fma}\left(\frac{0.16666666666666666}{\pi \cdot s} \cdot e^{-0.3333333333333333 \cdot \frac{r}{s}}, 0.75, \frac{0.125}{\left(e^{\frac{r}{s}} \cdot s\right) \cdot \pi}\right)}{r}
Initial program 99.6%
Applied rewrites99.6%
Applied rewrites99.6%
lift-fma.f32N/A
*-commutativeN/A
lower-fma.f3299.6%
Applied rewrites99.5%
(FPCore (s r) :precision binary32 (* (/ (+ (exp (* -0.3333333333333333 (/ r s))) (exp (/ (- r) s))) (* PI r)) (/ 0.125 s)))
float code(float s, float r) {
return ((expf((-0.3333333333333333f * (r / s))) + expf((-r / s))) / (((float) M_PI) * r)) * (0.125f / s);
}
function code(s, r) return Float32(Float32(Float32(exp(Float32(Float32(-0.3333333333333333) * Float32(r / s))) + exp(Float32(Float32(-r) / s))) / Float32(Float32(pi) * r)) * Float32(Float32(0.125) / s)) end
function tmp = code(s, r) tmp = ((exp((single(-0.3333333333333333) * (r / s))) + exp((-r / s))) / (single(pi) * r)) * (single(0.125) / s); end
\frac{e^{-0.3333333333333333 \cdot \frac{r}{s}} + e^{\frac{-r}{s}}}{\pi \cdot r} \cdot \frac{0.125}{s}
Initial program 99.6%
Applied rewrites99.6%
Applied rewrites99.5%
lift-/.f32N/A
lift-*.f32N/A
associate-/l*N/A
lower-*.f32N/A
Applied rewrites99.5%
(FPCore (s r) :precision binary32 (/ (* (+ (exp (* -0.3333333333333333 (/ r s))) (exp (/ (- r) s))) 0.125) (* (* PI r) s)))
float code(float s, float r) {
return ((expf((-0.3333333333333333f * (r / s))) + expf((-r / s))) * 0.125f) / ((((float) M_PI) * r) * s);
}
function code(s, r) return Float32(Float32(Float32(exp(Float32(Float32(-0.3333333333333333) * Float32(r / s))) + exp(Float32(Float32(-r) / s))) * Float32(0.125)) / Float32(Float32(Float32(pi) * r) * s)) end
function tmp = code(s, r) tmp = ((exp((single(-0.3333333333333333) * (r / s))) + exp((-r / s))) * single(0.125)) / ((single(pi) * r) * s); end
\frac{\left(e^{-0.3333333333333333 \cdot \frac{r}{s}} + e^{\frac{-r}{s}}\right) \cdot 0.125}{\left(\pi \cdot r\right) \cdot s}
Initial program 99.6%
Applied rewrites99.6%
Applied rewrites99.5%
lift-/.f32N/A
lift-*.f32N/A
associate-/l*N/A
lift-/.f32N/A
frac-timesN/A
lift-*.f32N/A
lower-/.f32N/A
Applied rewrites99.5%
(FPCore (s r) :precision binary32 (/ 0.25 (* (log (pow (exp PI) r)) s)))
float code(float s, float r) {
return 0.25f / (logf(powf(expf(((float) M_PI)), r)) * s);
}
function code(s, r) return Float32(Float32(0.25) / Float32(log((exp(Float32(pi)) ^ r)) * s)) end
function tmp = code(s, r) tmp = single(0.25) / (log((exp(single(pi)) ^ r)) * s); end
\frac{0.25}{\log \left({\left(e^{\pi}\right)}^{r}\right) \cdot s}
Initial program 99.6%
Taylor expanded in s around inf
lower-/.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f328.9%
Applied rewrites8.9%
lift-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-*r*N/A
lift-*.f32N/A
lower-*.f328.9%
lift-*.f32N/A
*-commutativeN/A
lower-*.f328.9%
Applied rewrites8.9%
lift-*.f32N/A
*-commutativeN/A
lift-PI.f32N/A
add-log-expN/A
log-pow-revN/A
lower-log.f32N/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-exp.f3243.9%
Applied rewrites43.9%
(FPCore (s r) :precision binary32 (/ 0.25 (log (pow (exp PI) (* s r)))))
float code(float s, float r) {
return 0.25f / logf(powf(expf(((float) M_PI)), (s * r)));
}
function code(s, r) return Float32(Float32(0.25) / log((exp(Float32(pi)) ^ Float32(s * r)))) end
function tmp = code(s, r) tmp = single(0.25) / log((exp(single(pi)) ^ (s * r))); end
\frac{0.25}{\log \left({\left(e^{\pi}\right)}^{\left(s \cdot r\right)}\right)}
Initial program 99.6%
Taylor expanded in s around inf
lower-/.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f328.9%
Applied rewrites8.9%
lift-*.f32N/A
lift-*.f32N/A
associate-*r*N/A
lift-PI.f32N/A
add-log-expN/A
log-pow-revN/A
lower-log.f32N/A
*-commutativeN/A
lower-pow.f32N/A
lift-PI.f32N/A
lower-exp.f32N/A
lower-*.f3210.1%
Applied rewrites10.1%
(FPCore (s r) :precision binary32 (/ (fma (/ (exp (/ (- r) s)) PI) 0.125 (/ 0.125 PI)) (* s r)))
float code(float s, float r) {
return fmaf((expf((-r / s)) / ((float) M_PI)), 0.125f, (0.125f / ((float) M_PI))) / (s * r);
}
function code(s, r) return Float32(fma(Float32(exp(Float32(Float32(-r) / s)) / Float32(pi)), Float32(0.125), Float32(Float32(0.125) / Float32(pi))) / Float32(s * r)) end
\frac{\mathsf{fma}\left(\frac{e^{\frac{-r}{s}}}{\pi}, 0.125, \frac{0.125}{\pi}\right)}{s \cdot r}
Initial program 99.6%
Applied rewrites99.6%
Taylor expanded in s around inf
lower-/.f32N/A
lower-PI.f329.4%
Applied rewrites9.4%
(FPCore (s r) :precision binary32 (/ (* (/ (+ 1.0 (exp (* -0.3333333333333333 (/ r s)))) (* PI r)) 0.125) s))
float code(float s, float r) {
return (((1.0f + expf((-0.3333333333333333f * (r / s)))) / (((float) M_PI) * r)) * 0.125f) / s;
}
function code(s, r) return Float32(Float32(Float32(Float32(Float32(1.0) + exp(Float32(Float32(-0.3333333333333333) * Float32(r / s)))) / Float32(Float32(pi) * r)) * Float32(0.125)) / s) end
function tmp = code(s, r) tmp = (((single(1.0) + exp((single(-0.3333333333333333) * (r / s)))) / (single(pi) * r)) * single(0.125)) / s; end
\frac{\frac{1 + e^{-0.3333333333333333 \cdot \frac{r}{s}}}{\pi \cdot r} \cdot 0.125}{s}
Initial program 99.6%
Applied rewrites99.6%
Applied rewrites99.5%
Taylor expanded in s around inf
Applied rewrites9.0%
(FPCore (s r) :precision binary32 (/ (/ (/ (fma (* (/ r (* PI s)) -0.16666666666666666) PI 0.25) PI) s) r))
float code(float s, float r) {
return ((fmaf(((r / (((float) M_PI) * s)) * -0.16666666666666666f), ((float) M_PI), 0.25f) / ((float) M_PI)) / s) / r;
}
function code(s, r) return Float32(Float32(Float32(fma(Float32(Float32(r / Float32(Float32(pi) * s)) * Float32(-0.16666666666666666)), Float32(pi), Float32(0.25)) / Float32(pi)) / s) / r) end
\frac{\frac{\frac{\mathsf{fma}\left(\frac{r}{\pi \cdot s} \cdot -0.16666666666666666, \pi, 0.25\right)}{\pi}}{s}}{r}
Initial program 99.6%
Applied rewrites99.6%
Taylor expanded in s around inf
lower-/.f32N/A
Applied rewrites8.9%
lift-fma.f32N/A
lift-fma.f32N/A
associate-+r+N/A
lift-*.f32N/A
lift-/.f32N/A
mult-flip-revN/A
add-to-fractionN/A
lower-/.f32N/A
Applied rewrites9.0%
(FPCore (s r) :precision binary32 (/ (/ (fma (/ r (* PI s)) -0.16666666666666666 0.07957746833562851) s) r))
float code(float s, float r) {
return (fmaf((r / (((float) M_PI) * s)), -0.16666666666666666f, 0.07957746833562851f) / s) / r;
}
function code(s, r) return Float32(Float32(fma(Float32(r / Float32(Float32(pi) * s)), Float32(-0.16666666666666666), Float32(0.07957746833562851)) / s) / r) end
\frac{\frac{\mathsf{fma}\left(\frac{r}{\pi \cdot s}, -0.16666666666666666, 0.07957746833562851\right)}{s}}{r}
Initial program 99.6%
Applied rewrites99.6%
Taylor expanded in s around inf
lower-/.f32N/A
Applied rewrites8.9%
Applied rewrites8.9%
Evaluated real constant8.9%
(FPCore (s r) :precision binary32 (* (/ 0.25 (* s r)) (/ 1.0 PI)))
float code(float s, float r) {
return (0.25f / (s * r)) * (1.0f / ((float) M_PI));
}
function code(s, r) return Float32(Float32(Float32(0.25) / Float32(s * r)) * Float32(Float32(1.0) / Float32(pi))) end
function tmp = code(s, r) tmp = (single(0.25) / (s * r)) * (single(1.0) / single(pi)); end
\frac{0.25}{s \cdot r} \cdot \frac{1}{\pi}
Initial program 99.6%
Taylor expanded in s around inf
lower-/.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f328.9%
Applied rewrites8.9%
lift-*.f32N/A
lift-*.f32N/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
lower-*.f328.9%
Applied rewrites8.9%
lift-/.f32N/A
metadata-evalN/A
lift-*.f32N/A
times-fracN/A
lift-/.f32N/A
lower-*.f32N/A
lower-/.f328.9%
Applied rewrites8.9%
(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(Float32(s * r) * Float32(pi))) end
function tmp = code(s, r) tmp = single(0.25) / ((s * r) * single(pi)); end
\frac{0.25}{\left(s \cdot r\right) \cdot \pi}
Initial program 99.6%
Taylor expanded in s around inf
lower-/.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f328.9%
Applied rewrites8.9%
lift-*.f32N/A
lift-*.f32N/A
associate-*r*N/A
*-commutativeN/A
lower-*.f32N/A
lower-*.f328.9%
Applied rewrites8.9%
(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
\frac{0.25}{r \cdot \left(s \cdot \pi\right)}
Initial program 99.6%
Taylor expanded in s around inf
lower-/.f32N/A
lower-*.f32N/A
lower-*.f32N/A
lower-PI.f328.9%
Applied rewrites8.9%
herbie shell --seed 2025193
(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))))