
(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 10 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
(fma
(* s 3.0)
(log1p (/ (+ 0.6666666666666666 (/ u 0.75)) (/ 0.75 (+ u -0.25))))
(*
s
(*
-3.0
(log1p (/ (+ u -0.25) (/ (/ -0.421875 (+ u -0.25)) (+ u -0.25))))))))
float code(float s, float u) {
return fmaf((s * 3.0f), log1pf(((0.6666666666666666f + (u / 0.75f)) / (0.75f / (u + -0.25f)))), (s * (-3.0f * log1pf(((u + -0.25f) / ((-0.421875f / (u + -0.25f)) / (u + -0.25f)))))));
}
function code(s, u) return fma(Float32(s * Float32(3.0)), log1p(Float32(Float32(Float32(0.6666666666666666) + Float32(u / Float32(0.75))) / Float32(Float32(0.75) / Float32(u + Float32(-0.25))))), Float32(s * Float32(Float32(-3.0) * log1p(Float32(Float32(u + Float32(-0.25)) / Float32(Float32(Float32(-0.421875) / Float32(u + Float32(-0.25))) / Float32(u + Float32(-0.25)))))))) end
\begin{array}{l}
\\
\mathsf{fma}\left(s \cdot 3, \mathsf{log1p}\left(\frac{0.6666666666666666 + \frac{u}{0.75}}{\frac{0.75}{u + -0.25}}\right), s \cdot \left(-3 \cdot \mathsf{log1p}\left(\frac{u + -0.25}{\frac{\frac{-0.421875}{u + -0.25}}{u + -0.25}}\right)\right)\right)
\end{array}
Initial program 95.8%
Applied egg-rr95.2%
log-prodN/A
distribute-lft-inN/A
fma-defineN/A
fma-lowering-fma.f32N/A
Applied egg-rr98.2%
+-commutativeN/A
fma-defineN/A
fma-lowering-fma.f32N/A
*-lowering-*.f32N/A
log1p-defineN/A
log1p-lowering-log1p.f32N/A
/-lowering-/.f32N/A
+-lowering-+.f32N/A
/-lowering-/.f32N/A
/-lowering-/.f32N/A
+-lowering-+.f32N/A
associate-*l*N/A
*-lowering-*.f32N/A
Applied egg-rr98.4%
(FPCore (s u) :precision binary32 (+ (* (log1p (/ (+ u -0.25) (/ (/ -0.421875 (+ u -0.25)) (+ u -0.25)))) (* s -3.0)) (* (* s 3.0) (log1p (/ (+ 0.6666666666666666 (/ u 0.75)) (/ 0.75 (+ u -0.25)))))))
float code(float s, float u) {
return (log1pf(((u + -0.25f) / ((-0.421875f / (u + -0.25f)) / (u + -0.25f)))) * (s * -3.0f)) + ((s * 3.0f) * log1pf(((0.6666666666666666f + (u / 0.75f)) / (0.75f / (u + -0.25f)))));
}
function code(s, u) return Float32(Float32(log1p(Float32(Float32(u + Float32(-0.25)) / Float32(Float32(Float32(-0.421875) / Float32(u + Float32(-0.25))) / Float32(u + Float32(-0.25))))) * Float32(s * Float32(-3.0))) + Float32(Float32(s * Float32(3.0)) * log1p(Float32(Float32(Float32(0.6666666666666666) + Float32(u / Float32(0.75))) / Float32(Float32(0.75) / Float32(u + Float32(-0.25))))))) end
\begin{array}{l}
\\
\mathsf{log1p}\left(\frac{u + -0.25}{\frac{\frac{-0.421875}{u + -0.25}}{u + -0.25}}\right) \cdot \left(s \cdot -3\right) + \left(s \cdot 3\right) \cdot \mathsf{log1p}\left(\frac{0.6666666666666666 + \frac{u}{0.75}}{\frac{0.75}{u + -0.25}}\right)
\end{array}
Initial program 95.8%
Applied egg-rr95.2%
log-prodN/A
distribute-lft-inN/A
fma-defineN/A
fma-lowering-fma.f32N/A
Applied egg-rr98.2%
+-commutativeN/A
fma-defineN/A
fma-lowering-fma.f32N/A
*-lowering-*.f32N/A
log1p-defineN/A
log1p-lowering-log1p.f32N/A
/-lowering-/.f32N/A
+-lowering-+.f32N/A
/-lowering-/.f32N/A
/-lowering-/.f32N/A
+-lowering-+.f32N/A
associate-*l*N/A
*-lowering-*.f32N/A
Applied egg-rr98.4%
Applied egg-rr98.2%
Final simplification98.2%
(FPCore (s u) :precision binary32 (* (* s -3.0) (- (log1p (/ (* (+ u -0.25) (* (+ u -0.25) (+ u -0.25))) -0.421875)) (log1p (* (+ 0.6666666666666666 (/ u 0.75)) (/ (+ u -0.25) 0.75))))))
float code(float s, float u) {
return (s * -3.0f) * (log1pf((((u + -0.25f) * ((u + -0.25f) * (u + -0.25f))) / -0.421875f)) - log1pf(((0.6666666666666666f + (u / 0.75f)) * ((u + -0.25f) / 0.75f))));
}
function code(s, u) return Float32(Float32(s * Float32(-3.0)) * Float32(log1p(Float32(Float32(Float32(u + Float32(-0.25)) * Float32(Float32(u + Float32(-0.25)) * Float32(u + Float32(-0.25)))) / Float32(-0.421875))) - log1p(Float32(Float32(Float32(0.6666666666666666) + Float32(u / Float32(0.75))) * Float32(Float32(u + Float32(-0.25)) / Float32(0.75)))))) end
\begin{array}{l}
\\
\left(s \cdot -3\right) \cdot \left(\mathsf{log1p}\left(\frac{\left(u + -0.25\right) \cdot \left(\left(u + -0.25\right) \cdot \left(u + -0.25\right)\right)}{-0.421875}\right) - \mathsf{log1p}\left(\left(0.6666666666666666 + \frac{u}{0.75}\right) \cdot \frac{u + -0.25}{0.75}\right)\right)
\end{array}
Initial program 95.8%
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-eval96.4%
Simplified96.4%
Applied egg-rr98.1%
Final simplification98.1%
(FPCore (s u)
:precision binary32
(*
(* s -3.0)
(-
(log1p (/ (* (+ u -0.25) (* (+ u -0.25) (+ u -0.25))) -0.421875))
(log1p
(*
(* (+ 0.6666666666666666 (/ u 0.75)) (+ u -0.25))
1.3333333333333333)))))
float code(float s, float u) {
return (s * -3.0f) * (log1pf((((u + -0.25f) * ((u + -0.25f) * (u + -0.25f))) / -0.421875f)) - log1pf((((0.6666666666666666f + (u / 0.75f)) * (u + -0.25f)) * 1.3333333333333333f)));
}
function code(s, u) return Float32(Float32(s * Float32(-3.0)) * Float32(log1p(Float32(Float32(Float32(u + Float32(-0.25)) * Float32(Float32(u + Float32(-0.25)) * Float32(u + Float32(-0.25)))) / Float32(-0.421875))) - log1p(Float32(Float32(Float32(Float32(0.6666666666666666) + Float32(u / Float32(0.75))) * Float32(u + Float32(-0.25))) * Float32(1.3333333333333333))))) end
\begin{array}{l}
\\
\left(s \cdot -3\right) \cdot \left(\mathsf{log1p}\left(\frac{\left(u + -0.25\right) \cdot \left(\left(u + -0.25\right) \cdot \left(u + -0.25\right)\right)}{-0.421875}\right) - \mathsf{log1p}\left(\left(\left(0.6666666666666666 + \frac{u}{0.75}\right) \cdot \left(u + -0.25\right)\right) \cdot 1.3333333333333333\right)\right)
\end{array}
Initial program 95.8%
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-eval96.4%
Simplified96.4%
Applied egg-rr98.1%
associate-*l/N/A
div-invN/A
metadata-evalN/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
+-lowering-+.f32N/A
/-lowering-/.f3298.0%
Applied egg-rr98.0%
Final simplification98.0%
(FPCore (s u) :precision binary32 (* (* s -3.0) (log1p (fma u -1.3333333333333333 0.3333333333333333))))
float code(float s, float u) {
return (s * -3.0f) * log1pf(fmaf(u, -1.3333333333333333f, 0.3333333333333333f));
}
function code(s, u) return Float32(Float32(s * Float32(-3.0)) * log1p(fma(u, Float32(-1.3333333333333333), Float32(0.3333333333333333)))) end
\begin{array}{l}
\\
\left(s \cdot -3\right) \cdot \mathsf{log1p}\left(\mathsf{fma}\left(u, -1.3333333333333333, 0.3333333333333333\right)\right)
\end{array}
Initial program 95.8%
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-eval96.4%
Simplified96.4%
+-commutativeN/A
div-invN/A
fma-defineN/A
fma-lowering-fma.f32N/A
metadata-eval98.0%
Applied egg-rr98.0%
Final simplification98.0%
(FPCore (s u) :precision binary32 (* (* s -3.0) (log1p (+ 0.3333333333333333 (* u -1.3333333333333333)))))
float code(float s, float u) {
return (s * -3.0f) * log1pf((0.3333333333333333f + (u * -1.3333333333333333f)));
}
function code(s, u) return Float32(Float32(s * Float32(-3.0)) * log1p(Float32(Float32(0.3333333333333333) + Float32(u * Float32(-1.3333333333333333))))) end
\begin{array}{l}
\\
\left(s \cdot -3\right) \cdot \mathsf{log1p}\left(0.3333333333333333 + u \cdot -1.3333333333333333\right)
\end{array}
Initial program 95.8%
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-eval96.4%
Simplified96.4%
Taylor expanded in s around 0
associate-*r*N/A
metadata-evalN/A
associate-+r+N/A
+-commutativeN/A
metadata-evalN/A
metadata-evalN/A
distribute-lft-inN/A
metadata-evalN/A
sub-negN/A
cancel-sign-sub-invN/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
sub-negN/A
log1p-defineN/A
log1p-lowering-log1p.f32N/A
distribute-lft-neg-inN/A
metadata-evalN/A
sub-negN/A
distribute-lft-inN/A
metadata-evalN/A
metadata-evalN/A
+-lowering-+.f32N/A
*-commutativeN/A
*-lowering-*.f3296.8%
Simplified96.8%
Final simplification96.8%
(FPCore (s u) :precision binary32 (* (* s -3.0) (log1p (+ 0.3333333333333333 (/ u -0.75)))))
float code(float s, float u) {
return (s * -3.0f) * log1pf((0.3333333333333333f + (u / -0.75f)));
}
function code(s, u) return Float32(Float32(s * Float32(-3.0)) * log1p(Float32(Float32(0.3333333333333333) + Float32(u / Float32(-0.75))))) end
\begin{array}{l}
\\
\left(s \cdot -3\right) \cdot \mathsf{log1p}\left(0.3333333333333333 + \frac{u}{-0.75}\right)
\end{array}
Initial program 95.8%
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-eval96.4%
Simplified96.4%
Final simplification96.4%
(FPCore (s u) :precision binary32 (* (* s -3.0) (log (+ 1.3333333333333333 (/ u -0.75)))))
float code(float s, float u) {
return (s * -3.0f) * logf((1.3333333333333333f + (u / -0.75f)));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = (s * (-3.0e0)) * log((1.3333333333333333e0 + (u / (-0.75e0))))
end function
function code(s, u) return Float32(Float32(s * Float32(-3.0)) * log(Float32(Float32(1.3333333333333333) + Float32(u / Float32(-0.75))))) end
function tmp = code(s, u) tmp = (s * single(-3.0)) * log((single(1.3333333333333333) + (u / single(-0.75)))); end
\begin{array}{l}
\\
\left(s \cdot -3\right) \cdot \log \left(1.3333333333333333 + \frac{u}{-0.75}\right)
\end{array}
Initial program 95.8%
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-eval96.4%
Simplified96.4%
+-commutativeN/A
associate-+r+N/A
frac-2negN/A
metadata-evalN/A
distribute-frac-negN/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-frac-negN/A
metadata-evalN/A
frac-2negN/A
associate-+r+N/A
+-commutativeN/A
associate-+r+N/A
metadata-evalN/A
metadata-evalN/A
+-commutativeN/A
+-lowering-+.f32N/A
Applied egg-rr94.7%
Final simplification94.7%
(FPCore (s u) :precision binary32 (* s (* 3.0 u)))
float code(float s, float u) {
return s * (3.0f * u);
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = s * (3.0e0 * u)
end function
function code(s, u) return Float32(s * Float32(Float32(3.0) * u)) end
function tmp = code(s, u) tmp = s * (single(3.0) * u); end
\begin{array}{l}
\\
s \cdot \left(3 \cdot u\right)
\end{array}
Initial program 95.8%
Taylor expanded in u around 0
+-lowering-+.f32N/A
*-commutativeN/A
*-lowering-*.f3295.3%
Simplified95.3%
Taylor expanded in u around 0
distribute-lft-outN/A
*-lowering-*.f32N/A
distribute-lft-outN/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
log-lowering-log.f3225.3%
Simplified25.3%
Taylor expanded in u around inf
associate-*r*N/A
*-commutativeN/A
associate-*l*N/A
*-lowering-*.f32N/A
*-commutativeN/A
*-lowering-*.f3229.8%
Simplified29.8%
Final simplification29.8%
(FPCore (s u) :precision binary32 (* 3.0 (* s u)))
float code(float s, float u) {
return 3.0f * (s * u);
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = 3.0e0 * (s * u)
end function
function code(s, u) return Float32(Float32(3.0) * Float32(s * u)) end
function tmp = code(s, u) tmp = single(3.0) * (s * u); end
\begin{array}{l}
\\
3 \cdot \left(s \cdot u\right)
\end{array}
Initial program 95.8%
Taylor expanded in u around 0
+-lowering-+.f32N/A
*-commutativeN/A
*-lowering-*.f3295.3%
Simplified95.3%
Taylor expanded in u around 0
distribute-lft-outN/A
*-lowering-*.f32N/A
distribute-lft-outN/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
log-lowering-log.f3225.3%
Simplified25.3%
Taylor expanded in u around inf
*-lowering-*.f3229.8%
Simplified29.8%
herbie shell --seed 2024170
(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))))))