
(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 11 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 (* (- (log1p (/ (* (+ u -0.25) (+ u -0.25)) (- 0.5625))) (log1p (fma u 1.3333333333333333 -0.3333333333333333))) (* s -3.0)))
float code(float s, float u) {
return (log1pf((((u + -0.25f) * (u + -0.25f)) / -0.5625f)) - log1pf(fmaf(u, 1.3333333333333333f, -0.3333333333333333f))) * (s * -3.0f);
}
function code(s, u) return Float32(Float32(log1p(Float32(Float32(Float32(u + Float32(-0.25)) * Float32(u + Float32(-0.25))) / Float32(-Float32(0.5625)))) - log1p(fma(u, Float32(1.3333333333333333), Float32(-0.3333333333333333)))) * Float32(s * Float32(-3.0))) end
\begin{array}{l}
\\
\left(\mathsf{log1p}\left(\frac{\left(u + -0.25\right) \cdot \left(u + -0.25\right)}{-0.5625}\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right)\right) \cdot \left(s \cdot -3\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-eval96.6%
Simplified96.6%
+-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
flip--N/A
log-divN/A
--lowering--.f32N/A
Applied egg-rr97.4%
div-invN/A
fma-defineN/A
fma-lowering-fma.f32N/A
metadata-eval98.5%
Applied egg-rr98.5%
Final simplification98.5%
(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-eval96.6%
Simplified96.6%
+-commutativeN/A
div-invN/A
fma-defineN/A
fma-lowering-fma.f32N/A
metadata-eval98.1%
Applied egg-rr98.1%
Final simplification98.1%
(FPCore (s u)
:precision binary32
(*
(* s -3.0)
(log1p
(*
u
(/
(- (/ 0.1111111111111111 (* u u)) 1.7777777777777777)
(- (/ 0.3333333333333333 u) -1.3333333333333333))))))
float code(float s, float u) {
return (s * -3.0f) * log1pf((u * (((0.1111111111111111f / (u * u)) - 1.7777777777777777f) / ((0.3333333333333333f / u) - -1.3333333333333333f))));
}
function code(s, u) return Float32(Float32(s * Float32(-3.0)) * log1p(Float32(u * Float32(Float32(Float32(Float32(0.1111111111111111) / Float32(u * u)) - Float32(1.7777777777777777)) / Float32(Float32(Float32(0.3333333333333333) / u) - Float32(-1.3333333333333333)))))) end
\begin{array}{l}
\\
\left(s \cdot -3\right) \cdot \mathsf{log1p}\left(u \cdot \frac{\frac{0.1111111111111111}{u \cdot u} - 1.7777777777777777}{\frac{0.3333333333333333}{u} - -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-eval96.6%
Simplified96.6%
Taylor expanded in u around inf
*-lowering-*.f32N/A
sub-negN/A
metadata-evalN/A
+-commutativeN/A
+-lowering-+.f32N/A
associate-*r/N/A
metadata-evalN/A
/-lowering-/.f3296.9%
Simplified96.9%
+-commutativeN/A
flip-+N/A
/-lowering-/.f32N/A
metadata-evalN/A
--lowering--.f32N/A
frac-timesN/A
metadata-evalN/A
/-lowering-/.f32N/A
*-lowering-*.f32N/A
--lowering--.f32N/A
/-lowering-/.f3297.0%
Applied egg-rr97.0%
Final simplification97.0%
(FPCore (s u) :precision binary32 (* s (* -3.0 (log1p (* u (+ -1.3333333333333333 (/ 0.3333333333333333 u)))))))
float code(float s, float u) {
return s * (-3.0f * log1pf((u * (-1.3333333333333333f + (0.3333333333333333f / u)))));
}
function code(s, u) return Float32(s * Float32(Float32(-3.0) * log1p(Float32(u * Float32(Float32(-1.3333333333333333) + Float32(Float32(0.3333333333333333) / u)))))) end
\begin{array}{l}
\\
s \cdot \left(-3 \cdot \mathsf{log1p}\left(u \cdot \left(-1.3333333333333333 + \frac{0.3333333333333333}{u}\right)\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-eval96.6%
Simplified96.6%
*-commutativeN/A
associate-*r*N/A
*-lowering-*.f32N/A
Applied egg-rr96.5%
Taylor expanded in u around inf
*-lowering-*.f32N/A
sub-negN/A
metadata-evalN/A
+-commutativeN/A
+-lowering-+.f32N/A
associate-*r/N/A
metadata-evalN/A
/-lowering-/.f3297.0%
Simplified97.0%
Final simplification97.0%
(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-eval96.6%
Simplified96.6%
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
Simplified96.9%
Final simplification96.9%
(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-eval96.6%
Simplified96.6%
Final simplification96.6%
(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-eval96.6%
Simplified96.6%
+-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 (log 0.75))))
float code(float s, float u) {
return (s * 3.0f) * (u + logf(0.75f));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = (s * 3.0e0) * (u + log(0.75e0))
end function
function code(s, u) return Float32(Float32(s * Float32(3.0)) * Float32(u + log(Float32(0.75)))) end
function tmp = code(s, u) tmp = (s * single(3.0)) * (u + log(single(0.75))); end
\begin{array}{l}
\\
\left(s \cdot 3\right) \cdot \left(u + \log 0.75\right)
\end{array}
Initial program 95.8%
Taylor expanded in u around 0
associate-*r*N/A
associate-*r*N/A
distribute-lft-outN/A
*-lowering-*.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
log-lowering-log.f3225.5%
Simplified25.5%
(FPCore (s u) :precision binary32 (* s (* 3.0 (+ u (log 0.75)))))
float code(float s, float u) {
return s * (3.0f * (u + logf(0.75f)));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = s * (3.0e0 * (u + log(0.75e0)))
end function
function code(s, u) return Float32(s * Float32(Float32(3.0) * Float32(u + log(Float32(0.75))))) end
function tmp = code(s, u) tmp = s * (single(3.0) * (u + log(single(0.75)))); end
\begin{array}{l}
\\
s \cdot \left(3 \cdot \left(u + \log 0.75\right)\right)
\end{array}
Initial program 95.8%
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
flip-+N/A
/-lowering-/.f32N/A
Applied egg-rr95.0%
Taylor expanded in u around 0
associate-*r*N/A
associate-*r*N/A
distribute-lft-outN/A
*-commutativeN/A
associate-*l*N/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
log-lowering-log.f3225.5%
Simplified25.5%
(FPCore (s u) :precision binary32 (* 3.0 (* s (log 0.75))))
float code(float s, float u) {
return 3.0f * (s * logf(0.75f));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = 3.0e0 * (s * log(0.75e0))
end function
function code(s, u) return Float32(Float32(3.0) * Float32(s * log(Float32(0.75)))) end
function tmp = code(s, u) tmp = single(3.0) * (s * log(single(0.75))); end
\begin{array}{l}
\\
3 \cdot \left(s \cdot \log 0.75\right)
\end{array}
Initial program 95.8%
Taylor expanded in u around 0
log-lowering-log.f327.7%
Simplified7.7%
associate-*l*N/A
*-commutativeN/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
log-lowering-log.f327.7%
Applied egg-rr7.7%
Final simplification7.7%
(FPCore (s u) :precision binary32 (* -3.0 (* s (log 1.3333333333333333))))
float code(float s, float u) {
return -3.0f * (s * logf(1.3333333333333333f));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = (-3.0e0) * (s * log(1.3333333333333333e0))
end function
function code(s, u) return Float32(Float32(-3.0) * Float32(s * log(Float32(1.3333333333333333)))) end
function tmp = code(s, u) tmp = single(-3.0) * (s * log(single(1.3333333333333333))); end
\begin{array}{l}
\\
-3 \cdot \left(s \cdot \log 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-eval96.6%
Simplified96.6%
Taylor expanded in u around 0
*-lowering-*.f32N/A
*-lowering-*.f32N/A
log-lowering-log.f327.7%
Simplified7.7%
herbie shell --seed 2024158
(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))))))