
(FPCore (s u) :precision binary32 (* (* 3.0 s) (log (/ 1.0 (- 1.0 (/ (- u 0.25) 0.75))))))
float code(float s, float u) {
return (3.0f * s) * logf((1.0f / (1.0f - ((u - 0.25f) / 0.75f))));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = (3.0e0 * s) * log((1.0e0 / (1.0e0 - ((u - 0.25e0) / 0.75e0))))
end function
function code(s, u) return Float32(Float32(Float32(3.0) * s) * log(Float32(Float32(1.0) / Float32(Float32(1.0) - Float32(Float32(u - Float32(0.25)) / Float32(0.75)))))) end
function tmp = code(s, u) tmp = (single(3.0) * s) * log((single(1.0) / (single(1.0) - ((u - single(0.25)) / single(0.75))))); end
\begin{array}{l}
\\
\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right)
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 5 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (s u) :precision binary32 (* (* 3.0 s) (log (/ 1.0 (- 1.0 (/ (- u 0.25) 0.75))))))
float code(float s, float u) {
return (3.0f * s) * logf((1.0f / (1.0f - ((u - 0.25f) / 0.75f))));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = (3.0e0 * s) * log((1.0e0 / (1.0e0 - ((u - 0.25e0) / 0.75e0))))
end function
function code(s, u) return Float32(Float32(Float32(3.0) * s) * log(Float32(Float32(1.0) / Float32(Float32(1.0) - Float32(Float32(u - Float32(0.25)) / Float32(0.75)))))) end
function tmp = code(s, u) tmp = (single(3.0) * s) * log((single(1.0) / (single(1.0) - ((u - single(0.25)) / single(0.75))))); end
\begin{array}{l}
\\
\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right)
\end{array}
(FPCore (s u) :precision binary32 (* (* -3.0 (log1p (/ (- 0.25 u) 0.75))) s))
float code(float s, float u) {
return (-3.0f * log1pf(((0.25f - u) / 0.75f))) * s;
}
function code(s, u) return Float32(Float32(Float32(-3.0) * log1p(Float32(Float32(Float32(0.25) - u) / Float32(0.75)))) * s) end
\begin{array}{l}
\\
\left(-3 \cdot \mathsf{log1p}\left(\frac{0.25 - u}{0.75}\right)\right) \cdot s
\end{array}
Initial program 95.9%
log-recN/A
neg-mul-1N/A
associate-*r*N/A
*-commutativeN/A
*-lowering-*.f32N/A
sub-negN/A
log1p-defineN/A
log1p-lowering-log1p.f32N/A
neg-sub0N/A
div-subN/A
associate--r-N/A
neg-sub0N/A
+-commutativeN/A
+-lowering-+.f32N/A
metadata-evalN/A
distribute-neg-frac2N/A
/-lowering-/.f32N/A
metadata-evalN/A
*-commutativeN/A
associate-*l*N/A
*-lowering-*.f32N/A
metadata-eval96.5%
Simplified96.5%
*-commutativeN/A
+-commutativeN/A
associate-+r+N/A
metadata-evalN/A
distribute-neg-frac2N/A
sub-negN/A
associate--r-N/A
metadata-evalN/A
div-subN/A
metadata-evalN/A
distribute-lft-neg-inN/A
distribute-rgt-neg-inN/A
distribute-lft-neg-outN/A
log-recN/A
associate-*r*N/A
*-lowering-*.f32N/A
Applied egg-rr96.6%
metadata-evalN/A
distribute-neg-frac2N/A
sub-negN/A
metadata-evalN/A
div-subN/A
remove-double-divN/A
/-lowering-/.f32N/A
remove-double-divN/A
--lowering--.f3298.3%
Applied egg-rr98.3%
(FPCore (s u) :precision binary32 (* (log1p (/ (- 0.25 u) 0.75)) (* -3.0 s)))
float code(float s, float u) {
return log1pf(((0.25f - u) / 0.75f)) * (-3.0f * s);
}
function code(s, u) return Float32(log1p(Float32(Float32(Float32(0.25) - u) / Float32(0.75))) * Float32(Float32(-3.0) * s)) end
\begin{array}{l}
\\
\mathsf{log1p}\left(\frac{0.25 - u}{0.75}\right) \cdot \left(-3 \cdot s\right)
\end{array}
Initial program 95.9%
log-recN/A
neg-mul-1N/A
associate-*r*N/A
*-commutativeN/A
*-lowering-*.f32N/A
sub-negN/A
log1p-defineN/A
log1p-lowering-log1p.f32N/A
neg-sub0N/A
div-subN/A
associate--r-N/A
neg-sub0N/A
+-commutativeN/A
+-lowering-+.f32N/A
metadata-evalN/A
distribute-neg-frac2N/A
/-lowering-/.f32N/A
metadata-evalN/A
*-commutativeN/A
associate-*l*N/A
*-lowering-*.f32N/A
metadata-eval96.5%
Simplified96.5%
+-commutativeN/A
metadata-evalN/A
metadata-evalN/A
sub-negN/A
metadata-evalN/A
metadata-evalN/A
div-subN/A
frac-2negN/A
metadata-evalN/A
/-lowering-/.f32N/A
sub-negN/A
distribute-neg-inN/A
metadata-evalN/A
metadata-evalN/A
+-commutativeN/A
sub-negN/A
--lowering--.f3298.2%
Applied egg-rr98.2%
Final simplification98.2%
(FPCore (s u) :precision binary32 (* (* -3.0 s) (log1p (* (- 0.25 u) 1.3333333333333333))))
float code(float s, float u) {
return (-3.0f * s) * log1pf(((0.25f - u) * 1.3333333333333333f));
}
function code(s, u) return Float32(Float32(Float32(-3.0) * s) * log1p(Float32(Float32(Float32(0.25) - u) * Float32(1.3333333333333333)))) end
\begin{array}{l}
\\
\left(-3 \cdot s\right) \cdot \mathsf{log1p}\left(\left(0.25 - u\right) \cdot 1.3333333333333333\right)
\end{array}
Initial program 95.9%
log-recN/A
neg-mul-1N/A
associate-*r*N/A
*-commutativeN/A
*-lowering-*.f32N/A
sub-negN/A
log1p-defineN/A
log1p-lowering-log1p.f32N/A
neg-sub0N/A
div-subN/A
associate--r-N/A
neg-sub0N/A
+-commutativeN/A
+-lowering-+.f32N/A
metadata-evalN/A
distribute-neg-frac2N/A
/-lowering-/.f32N/A
metadata-evalN/A
*-commutativeN/A
associate-*l*N/A
*-lowering-*.f32N/A
metadata-eval96.5%
Simplified96.5%
+-commutativeN/A
metadata-evalN/A
metadata-evalN/A
sub-negN/A
metadata-evalN/A
metadata-evalN/A
div-subN/A
frac-2negN/A
metadata-evalN/A
div-invN/A
*-lowering-*.f32N/A
sub-negN/A
distribute-neg-inN/A
metadata-evalN/A
metadata-evalN/A
+-commutativeN/A
sub-negN/A
--lowering--.f32N/A
metadata-eval97.9%
Applied egg-rr97.9%
Final simplification97.9%
(FPCore (s u) :precision binary32 (* (* -3.0 s) (log (+ 1.3333333333333333 (/ u -0.75)))))
float code(float s, float u) {
return (-3.0f * s) * logf((1.3333333333333333f + (u / -0.75f)));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = ((-3.0e0) * s) * log((1.3333333333333333e0 + (u / (-0.75e0))))
end function
function code(s, u) return Float32(Float32(Float32(-3.0) * s) * log(Float32(Float32(1.3333333333333333) + Float32(u / Float32(-0.75))))) end
function tmp = code(s, u) tmp = (single(-3.0) * s) * log((single(1.3333333333333333) + (u / single(-0.75)))); end
\begin{array}{l}
\\
\left(-3 \cdot s\right) \cdot \log \left(1.3333333333333333 + \frac{u}{-0.75}\right)
\end{array}
Initial program 95.9%
log-recN/A
neg-mul-1N/A
associate-*r*N/A
*-commutativeN/A
*-lowering-*.f32N/A
sub-negN/A
log1p-defineN/A
log1p-lowering-log1p.f32N/A
neg-sub0N/A
div-subN/A
associate--r-N/A
neg-sub0N/A
+-commutativeN/A
+-lowering-+.f32N/A
metadata-evalN/A
distribute-neg-frac2N/A
/-lowering-/.f32N/A
metadata-evalN/A
*-commutativeN/A
associate-*l*N/A
*-lowering-*.f32N/A
metadata-eval96.5%
Simplified96.5%
+-commutativeN/A
associate-+r+N/A
metadata-evalN/A
distribute-neg-frac2N/A
sub-negN/A
associate--r-N/A
metadata-evalN/A
div-subN/A
log-lowering-log.f32N/A
div-subN/A
metadata-evalN/A
associate--r-N/A
sub-negN/A
distribute-neg-frac2N/A
metadata-evalN/A
+-commutativeN/A
associate-+l+N/A
metadata-evalN/A
metadata-evalN/A
+-lowering-+.f32N/A
/-lowering-/.f32N/A
metadata-eval94.9%
Applied egg-rr94.9%
Final simplification94.9%
(FPCore (s u) :precision binary32 (* s (* u 4.0)))
float code(float s, float u) {
return s * (u * 4.0f);
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = s * (u * 4.0e0)
end function
function code(s, u) return Float32(s * Float32(u * Float32(4.0))) end
function tmp = code(s, u) tmp = s * (u * single(4.0)); end
\begin{array}{l}
\\
s \cdot \left(u \cdot 4\right)
\end{array}
Initial program 95.9%
log-recN/A
neg-mul-1N/A
associate-*r*N/A
*-commutativeN/A
*-lowering-*.f32N/A
sub-negN/A
log1p-defineN/A
log1p-lowering-log1p.f32N/A
neg-sub0N/A
div-subN/A
associate--r-N/A
neg-sub0N/A
+-commutativeN/A
+-lowering-+.f32N/A
metadata-evalN/A
distribute-neg-frac2N/A
/-lowering-/.f32N/A
metadata-evalN/A
*-commutativeN/A
associate-*l*N/A
*-lowering-*.f32N/A
metadata-eval96.5%
Simplified96.5%
+-commutativeN/A
metadata-evalN/A
metadata-evalN/A
sub-negN/A
metadata-evalN/A
metadata-evalN/A
div-subN/A
frac-2negN/A
metadata-evalN/A
/-lowering-/.f32N/A
sub-negN/A
distribute-neg-inN/A
metadata-evalN/A
metadata-evalN/A
+-commutativeN/A
sub-negN/A
--lowering--.f3298.2%
Applied egg-rr98.2%
Taylor expanded in u around inf
mul-1-negN/A
neg-lowering-neg.f3218.1%
Simplified18.1%
Taylor expanded in u around 0
*-commutativeN/A
associate-*l*N/A
*-lowering-*.f32N/A
*-lowering-*.f3229.5%
Simplified29.5%
herbie shell --seed 2024164
(FPCore (s u)
:name "Disney BSSRDF, sample scattering profile, upper"
:precision binary32
:pre (and (and (<= 0.0 s) (<= s 256.0)) (and (<= 0.25 u) (<= u 1.0)))
(* (* 3.0 s) (log (/ 1.0 (- 1.0 (/ (- u 0.25) 0.75))))))