
(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 16 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)))) (* r (* s (* 2.0 PI)))) (/ (* 0.75 (exp (/ r (* s (- 3.0))))) (* (* r (* s PI)) 6.0))))
float code(float s, float r) {
return ((0.25f * expf((r / -s))) / (r * (s * (2.0f * ((float) M_PI))))) + ((0.75f * expf((r / (s * -3.0f)))) / ((r * (s * ((float) M_PI))) * 6.0f));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) * exp(Float32(r / Float32(-s)))) / Float32(r * Float32(s * Float32(Float32(2.0) * Float32(pi))))) + Float32(Float32(Float32(0.75) * exp(Float32(r / Float32(s * Float32(-Float32(3.0)))))) / Float32(Float32(r * Float32(s * Float32(pi))) * Float32(6.0)))) end
function tmp = code(s, r) tmp = ((single(0.25) * exp((r / -s))) / (r * (s * (single(2.0) * single(pi))))) + ((single(0.75) * exp((r / (s * -single(3.0))))) / ((r * (s * single(pi))) * single(6.0))); end
\begin{array}{l}
\\
\frac{0.25 \cdot e^{\frac{r}{-s}}}{r \cdot \left(s \cdot \left(2 \cdot \pi\right)\right)} + \frac{0.75 \cdot e^{\frac{r}{s \cdot \left(-3\right)}}}{\left(r \cdot \left(s \cdot \pi\right)\right) \cdot 6}
\end{array}
Initial program 99.7%
Taylor expanded in s around 0 99.8%
*-commutative99.8%
Simplified99.8%
Final simplification99.8%
(FPCore (s r) :precision binary32 (+ (/ (* 0.25 (exp (/ r (- s)))) (* r (* s (* 2.0 PI)))) (/ (* 0.75 (exp (* (/ r s) -0.3333333333333333))) (* (* r PI) (* s 6.0)))))
float code(float s, float r) {
return ((0.25f * expf((r / -s))) / (r * (s * (2.0f * ((float) M_PI))))) + ((0.75f * expf(((r / s) * -0.3333333333333333f))) / ((r * ((float) M_PI)) * (s * 6.0f)));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) * exp(Float32(r / Float32(-s)))) / Float32(r * Float32(s * Float32(Float32(2.0) * Float32(pi))))) + Float32(Float32(Float32(0.75) * exp(Float32(Float32(r / s) * Float32(-0.3333333333333333)))) / Float32(Float32(r * Float32(pi)) * Float32(s * Float32(6.0))))) end
function tmp = code(s, r) tmp = ((single(0.25) * exp((r / -s))) / (r * (s * (single(2.0) * single(pi))))) + ((single(0.75) * exp(((r / s) * single(-0.3333333333333333)))) / ((r * single(pi)) * (s * single(6.0)))); end
\begin{array}{l}
\\
\frac{0.25 \cdot e^{\frac{r}{-s}}}{r \cdot \left(s \cdot \left(2 \cdot \pi\right)\right)} + \frac{0.75 \cdot e^{\frac{r}{s} \cdot -0.3333333333333333}}{\left(r \cdot \pi\right) \cdot \left(s \cdot 6\right)}
\end{array}
Initial program 99.7%
Taylor expanded in s around 0 99.8%
*-commutative99.8%
Simplified99.8%
Taylor expanded in r around 0 99.8%
*-commutative99.8%
*-commutative99.8%
associate-*r*99.7%
associate-*l*99.8%
*-commutative99.8%
Simplified99.8%
Taylor expanded in r around 0 99.7%
*-commutative99.7%
Simplified99.7%
Final simplification99.7%
(FPCore (s r) :precision binary32 (* (/ 0.125 s) (/ (+ (/ (exp (/ r (- s))) r) (/ (exp (* r (/ -0.3333333333333333 s))) r)) PI)))
float code(float s, float r) {
return (0.125f / s) * (((expf((r / -s)) / r) + (expf((r * (-0.3333333333333333f / s))) / r)) / ((float) M_PI));
}
function code(s, r) return Float32(Float32(Float32(0.125) / s) * Float32(Float32(Float32(exp(Float32(r / Float32(-s))) / r) + Float32(exp(Float32(r * Float32(Float32(-0.3333333333333333) / s))) / r)) / Float32(pi))) end
function tmp = code(s, r) tmp = (single(0.125) / s) * (((exp((r / -s)) / r) + (exp((r * (single(-0.3333333333333333) / s))) / r)) / single(pi)); end
\begin{array}{l}
\\
\frac{0.125}{s} \cdot \frac{\frac{e^{\frac{r}{-s}}}{r} + \frac{e^{r \cdot \frac{-0.3333333333333333}{s}}}{r}}{\pi}
\end{array}
Initial program 99.7%
Simplified99.6%
Taylor expanded in s around 0 99.7%
associate-*r/99.7%
times-frac99.7%
mul-1-neg99.7%
distribute-neg-frac299.7%
*-commutative99.7%
associate-*l/99.7%
associate-/l*99.7%
Simplified99.7%
Final simplification99.7%
(FPCore (s r) :precision binary32 (* (/ 0.125 (* s PI)) (/ (+ (exp (/ r (- s))) (exp (* (/ r s) -0.3333333333333333))) r)))
float code(float s, float r) {
return (0.125f / (s * ((float) M_PI))) * ((expf((r / -s)) + expf(((r / s) * -0.3333333333333333f))) / r);
}
function code(s, r) return Float32(Float32(Float32(0.125) / Float32(s * Float32(pi))) * Float32(Float32(exp(Float32(r / Float32(-s))) + exp(Float32(Float32(r / s) * Float32(-0.3333333333333333)))) / r)) end
function tmp = code(s, r) tmp = (single(0.125) / (s * single(pi))) * ((exp((r / -s)) + exp(((r / s) * single(-0.3333333333333333)))) / r); end
\begin{array}{l}
\\
\frac{0.125}{s \cdot \pi} \cdot \frac{e^{\frac{r}{-s}} + e^{\frac{r}{s} \cdot -0.3333333333333333}}{r}
\end{array}
Initial program 99.7%
Simplified99.6%
Taylor expanded in r around inf 99.7%
associate-*r/99.7%
*-commutative99.7%
times-frac99.6%
mul-1-neg99.6%
distribute-neg-frac299.6%
*-commutative99.6%
associate-*l/99.6%
associate-/l*99.6%
Simplified99.6%
Taylor expanded in r around 0 99.6%
Final simplification99.6%
(FPCore (s r) :precision binary32 (* 0.125 (/ (+ (exp (/ r (- s))) (exp (* (/ r s) -0.3333333333333333))) (* r (* s PI)))))
float code(float s, float r) {
return 0.125f * ((expf((r / -s)) + expf(((r / s) * -0.3333333333333333f))) / (r * (s * ((float) M_PI))));
}
function code(s, r) return Float32(Float32(0.125) * Float32(Float32(exp(Float32(r / Float32(-s))) + exp(Float32(Float32(r / s) * Float32(-0.3333333333333333)))) / Float32(r * Float32(s * Float32(pi))))) end
function tmp = code(s, r) tmp = single(0.125) * ((exp((r / -s)) + exp(((r / s) * single(-0.3333333333333333)))) / (r * (s * single(pi)))); end
\begin{array}{l}
\\
0.125 \cdot \frac{e^{\frac{r}{-s}} + e^{\frac{r}{s} \cdot -0.3333333333333333}}{r \cdot \left(s \cdot \pi\right)}
\end{array}
Initial program 99.7%
Simplified99.6%
Taylor expanded in r around inf 99.7%
Final simplification99.7%
(FPCore (s r) :precision binary32 (/ 0.25 (log1p (expm1 (* r (* s PI))))))
float code(float s, float r) {
return 0.25f / log1pf(expm1f((r * (s * ((float) M_PI)))));
}
function code(s, r) return Float32(Float32(0.25) / log1p(expm1(Float32(r * Float32(s * Float32(pi)))))) end
\begin{array}{l}
\\
\frac{0.25}{\mathsf{log1p}\left(\mathsf{expm1}\left(r \cdot \left(s \cdot \pi\right)\right)\right)}
\end{array}
Initial program 99.7%
Simplified99.6%
Taylor expanded in s around inf 8.7%
log1p-expm1-u9.9%
*-commutative9.9%
Applied egg-rr9.9%
Final simplification9.9%
(FPCore (s r) :precision binary32 (/ 0.25 (* s (log1p (expm1 (* r PI))))))
float code(float s, float r) {
return 0.25f / (s * log1pf(expm1f((r * ((float) M_PI)))));
}
function code(s, r) return Float32(Float32(0.25) / Float32(s * log1p(expm1(Float32(r * Float32(pi)))))) end
\begin{array}{l}
\\
\frac{0.25}{s \cdot \mathsf{log1p}\left(\mathsf{expm1}\left(r \cdot \pi\right)\right)}
\end{array}
Initial program 99.7%
Simplified99.6%
Taylor expanded in s around inf 8.7%
pow18.7%
*-commutative8.7%
Applied egg-rr8.7%
unpow18.7%
*-commutative8.7%
*-commutative8.7%
associate-*l*8.7%
Simplified8.7%
log1p-expm1-u40.5%
Applied egg-rr40.5%
Final simplification40.5%
(FPCore (s r) :precision binary32 (* (/ 0.125 s) (/ (+ (/ (exp (* r (/ -0.3333333333333333 s))) r) (/ (- 1.0 (/ r s)) r)) PI)))
float code(float s, float r) {
return (0.125f / s) * (((expf((r * (-0.3333333333333333f / s))) / r) + ((1.0f - (r / s)) / r)) / ((float) M_PI));
}
function code(s, r) return Float32(Float32(Float32(0.125) / s) * Float32(Float32(Float32(exp(Float32(r * Float32(Float32(-0.3333333333333333) / s))) / r) + Float32(Float32(Float32(1.0) - Float32(r / s)) / r)) / Float32(pi))) end
function tmp = code(s, r) tmp = (single(0.125) / s) * (((exp((r * (single(-0.3333333333333333) / s))) / r) + ((single(1.0) - (r / s)) / r)) / single(pi)); end
\begin{array}{l}
\\
\frac{0.125}{s} \cdot \frac{\frac{e^{r \cdot \frac{-0.3333333333333333}{s}}}{r} + \frac{1 - \frac{r}{s}}{r}}{\pi}
\end{array}
Initial program 99.7%
Simplified99.6%
Taylor expanded in s around 0 99.7%
associate-*r/99.7%
times-frac99.7%
mul-1-neg99.7%
distribute-neg-frac299.7%
*-commutative99.7%
associate-*l/99.7%
associate-/l*99.7%
Simplified99.7%
Taylor expanded in r around 0 9.4%
mul-1-neg9.4%
unsub-neg9.4%
Simplified9.4%
Final simplification9.4%
(FPCore (s r) :precision binary32 (* (/ 0.125 (* s PI)) (/ (+ (exp (* r (/ -0.3333333333333333 s))) (- 1.0 (/ r s))) r)))
float code(float s, float r) {
return (0.125f / (s * ((float) M_PI))) * ((expf((r * (-0.3333333333333333f / s))) + (1.0f - (r / s))) / r);
}
function code(s, r) return Float32(Float32(Float32(0.125) / Float32(s * Float32(pi))) * Float32(Float32(exp(Float32(r * Float32(Float32(-0.3333333333333333) / s))) + Float32(Float32(1.0) - Float32(r / s))) / r)) end
function tmp = code(s, r) tmp = (single(0.125) / (s * single(pi))) * ((exp((r * (single(-0.3333333333333333) / s))) + (single(1.0) - (r / s))) / r); end
\begin{array}{l}
\\
\frac{0.125}{s \cdot \pi} \cdot \frac{e^{r \cdot \frac{-0.3333333333333333}{s}} + \left(1 - \frac{r}{s}\right)}{r}
\end{array}
Initial program 99.7%
Simplified99.6%
Taylor expanded in r around inf 99.7%
associate-*r/99.7%
*-commutative99.7%
times-frac99.6%
mul-1-neg99.6%
distribute-neg-frac299.6%
*-commutative99.6%
associate-*l/99.6%
associate-/l*99.6%
Simplified99.6%
Taylor expanded in r around 0 9.4%
mul-1-neg9.4%
unsub-neg9.4%
Simplified9.4%
Final simplification9.4%
(FPCore (s r) :precision binary32 (+ (/ (/ -0.16666666666666666 PI) (pow s 2.0)) (/ 0.25 (* s (* r PI)))))
float code(float s, float r) {
return ((-0.16666666666666666f / ((float) M_PI)) / powf(s, 2.0f)) + (0.25f / (s * (r * ((float) M_PI))));
}
function code(s, r) return Float32(Float32(Float32(Float32(-0.16666666666666666) / Float32(pi)) / (s ^ Float32(2.0))) + Float32(Float32(0.25) / Float32(s * Float32(r * Float32(pi))))) end
function tmp = code(s, r) tmp = ((single(-0.16666666666666666) / single(pi)) / (s ^ single(2.0))) + (single(0.25) / (s * (r * single(pi)))); end
\begin{array}{l}
\\
\frac{\frac{-0.16666666666666666}{\pi}}{{s}^{2}} + \frac{0.25}{s \cdot \left(r \cdot \pi\right)}
\end{array}
Initial program 99.7%
Simplified99.6%
Taylor expanded in r around inf 99.7%
associate-*r/99.7%
*-commutative99.7%
times-frac99.6%
mul-1-neg99.6%
distribute-neg-frac299.6%
*-commutative99.6%
associate-*l/99.6%
associate-/l*99.6%
Simplified99.6%
Taylor expanded in r around 0 99.6%
Taylor expanded in s around inf 9.3%
sub-neg9.3%
associate-*r/9.3%
metadata-eval9.3%
*-commutative9.3%
*-commutative9.3%
*-commutative9.3%
associate-*l*9.3%
*-commutative9.3%
associate-*r/9.3%
metadata-eval9.3%
*-commutative9.3%
distribute-neg-frac9.3%
metadata-eval9.3%
associate-/r*9.3%
Simplified9.3%
Final simplification9.3%
(FPCore (s r) :precision binary32 (+ (/ (/ 0.25 r) (* s PI)) (/ -0.16666666666666666 (* PI (pow s 2.0)))))
float code(float s, float r) {
return ((0.25f / r) / (s * ((float) M_PI))) + (-0.16666666666666666f / (((float) M_PI) * powf(s, 2.0f)));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) / r) / Float32(s * Float32(pi))) + Float32(Float32(-0.16666666666666666) / Float32(Float32(pi) * (s ^ Float32(2.0))))) end
function tmp = code(s, r) tmp = ((single(0.25) / r) / (s * single(pi))) + (single(-0.16666666666666666) / (single(pi) * (s ^ single(2.0)))); end
\begin{array}{l}
\\
\frac{\frac{0.25}{r}}{s \cdot \pi} + \frac{-0.16666666666666666}{\pi \cdot {s}^{2}}
\end{array}
Initial program 99.7%
Simplified99.6%
Taylor expanded in s around 0 99.7%
associate-*r/99.7%
times-frac99.7%
mul-1-neg99.7%
distribute-neg-frac299.7%
*-commutative99.7%
associate-*l/99.7%
associate-/l*99.7%
Simplified99.7%
Taylor expanded in s around inf 9.3%
sub-neg9.3%
associate-*r/9.3%
metadata-eval9.3%
associate-/r*9.3%
associate-*r/9.3%
metadata-eval9.3%
distribute-neg-frac9.3%
metadata-eval9.3%
*-commutative9.3%
Simplified9.3%
Final simplification9.3%
(FPCore (s r) :precision binary32 (+ (/ (/ 0.25 r) (* s PI)) (/ (/ -0.16666666666666666 PI) (pow s 2.0))))
float code(float s, float r) {
return ((0.25f / r) / (s * ((float) M_PI))) + ((-0.16666666666666666f / ((float) M_PI)) / powf(s, 2.0f));
}
function code(s, r) return Float32(Float32(Float32(Float32(0.25) / r) / Float32(s * Float32(pi))) + Float32(Float32(Float32(-0.16666666666666666) / Float32(pi)) / (s ^ Float32(2.0)))) end
function tmp = code(s, r) tmp = ((single(0.25) / r) / (s * single(pi))) + ((single(-0.16666666666666666) / single(pi)) / (s ^ single(2.0))); end
\begin{array}{l}
\\
\frac{\frac{0.25}{r}}{s \cdot \pi} + \frac{\frac{-0.16666666666666666}{\pi}}{{s}^{2}}
\end{array}
Initial program 99.7%
Simplified99.6%
Taylor expanded in r around 0 8.6%
Taylor expanded in s around 0 8.6%
associate--l+8.6%
*-commutative8.6%
un-div-inv8.6%
*-commutative8.6%
*-commutative8.6%
Applied egg-rr8.6%
Taylor expanded in r around 0 9.3%
sub-neg9.3%
associate-*r/9.3%
metadata-eval9.3%
associate-/r*9.3%
associate-*r/9.3%
metadata-eval9.3%
*-commutative9.3%
distribute-neg-frac9.3%
metadata-eval9.3%
associate-/r*9.3%
Simplified9.3%
Final simplification9.3%
(FPCore (s r) :precision binary32 (- (/ 0.25 (* r (* s PI))) (/ 0.16666666666666666 (* PI (pow s 2.0)))))
float code(float s, float r) {
return (0.25f / (r * (s * ((float) M_PI)))) - (0.16666666666666666f / (((float) M_PI) * powf(s, 2.0f)));
}
function code(s, r) return Float32(Float32(Float32(0.25) / Float32(r * Float32(s * Float32(pi)))) - Float32(Float32(0.16666666666666666) / Float32(Float32(pi) * (s ^ Float32(2.0))))) end
function tmp = code(s, r) tmp = (single(0.25) / (r * (s * single(pi)))) - (single(0.16666666666666666) / (single(pi) * (s ^ single(2.0)))); end
\begin{array}{l}
\\
\frac{0.25}{r \cdot \left(s \cdot \pi\right)} - \frac{0.16666666666666666}{\pi \cdot {s}^{2}}
\end{array}
Initial program 99.7%
Simplified99.6%
Taylor expanded in s around inf 9.3%
associate-*r/9.3%
metadata-eval9.3%
associate-*r/9.3%
metadata-eval9.3%
*-commutative9.3%
Simplified9.3%
Final simplification9.3%
(FPCore (s r) :precision binary32 (* (/ 0.25 r) (/ 1.0 (* s PI))))
float code(float s, float r) {
return (0.25f / r) * (1.0f / (s * ((float) M_PI)));
}
function code(s, r) return Float32(Float32(Float32(0.25) / r) * Float32(Float32(1.0) / Float32(s * Float32(pi)))) end
function tmp = code(s, r) tmp = (single(0.25) / r) * (single(1.0) / (s * single(pi))); end
\begin{array}{l}
\\
\frac{0.25}{r} \cdot \frac{1}{s \cdot \pi}
\end{array}
Initial program 99.7%
Simplified99.6%
Taylor expanded in s around 0 99.7%
associate-*r/99.7%
times-frac99.7%
mul-1-neg99.7%
distribute-neg-frac299.7%
*-commutative99.7%
associate-*l/99.7%
associate-/l*99.7%
Simplified99.7%
Taylor expanded in s around inf 8.7%
associate-/r*8.7%
Simplified8.7%
div-inv8.7%
Applied egg-rr8.7%
Final simplification8.7%
(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 99.7%
Simplified99.6%
Taylor expanded in s around inf 8.7%
Final simplification8.7%
(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(Float32(0.25) / r) / Float32(s * Float32(pi))) end
function tmp = code(s, r) tmp = (single(0.25) / r) / (s * single(pi)); end
\begin{array}{l}
\\
\frac{\frac{0.25}{r}}{s \cdot \pi}
\end{array}
Initial program 99.7%
Simplified99.6%
Taylor expanded in s around 0 99.7%
associate-*r/99.7%
times-frac99.7%
mul-1-neg99.7%
distribute-neg-frac299.7%
*-commutative99.7%
associate-*l/99.7%
associate-/l*99.7%
Simplified99.7%
Taylor expanded in s around inf 8.7%
associate-/r*8.7%
Simplified8.7%
Final simplification8.7%
herbie shell --seed 2024046
(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))))