
(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
(*
s
(+
(*
-3.0
(log1p
(* (* (+ u -0.25) (+ u -0.25)) (* (+ u -0.25) -2.3703703703703702))))
(*
3.0
(log1p (* (+ u -0.25) (+ 0.8888888888888888 (* u 1.7777777777777777))))))))
float code(float s, float u) {
return s * ((-3.0f * log1pf((((u + -0.25f) * (u + -0.25f)) * ((u + -0.25f) * -2.3703703703703702f)))) + (3.0f * log1pf(((u + -0.25f) * (0.8888888888888888f + (u * 1.7777777777777777f))))));
}
function code(s, u) return Float32(s * Float32(Float32(Float32(-3.0) * log1p(Float32(Float32(Float32(u + Float32(-0.25)) * Float32(u + Float32(-0.25))) * Float32(Float32(u + Float32(-0.25)) * Float32(-2.3703703703703702))))) + Float32(Float32(3.0) * log1p(Float32(Float32(u + Float32(-0.25)) * Float32(Float32(0.8888888888888888) + Float32(u * Float32(1.7777777777777777)))))))) end
\begin{array}{l}
\\
s \cdot \left(-3 \cdot \mathsf{log1p}\left(\left(\left(u + -0.25\right) \cdot \left(u + -0.25\right)\right) \cdot \left(\left(u + -0.25\right) \cdot -2.3703703703703702\right)\right) + 3 \cdot \mathsf{log1p}\left(\left(u + -0.25\right) \cdot \left(0.8888888888888888 + u \cdot 1.7777777777777777\right)\right)\right)
\end{array}
Initial program 95.5%
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-eval96.3%
Simplified96.3%
Applied egg-rr98.2%
distribute-rgt-inN/A
*-commutativeN/A
+-commutativeN/A
+-lowering-+.f32N/A
frac-timesN/A
/-lowering-/.f32N/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
metadata-evalN/A
div-invN/A
metadata-evalN/A
associate-*l*N/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
metadata-eval98.3%
Applied egg-rr98.3%
*-commutativeN/A
sub-negN/A
distribute-lft-inN/A
+-lowering-+.f32N/A
Applied egg-rr98.4%
Taylor expanded in s around 0
*-lowering-*.f32N/A
+-lowering-+.f32N/A
Simplified98.6%
(FPCore (s u) :precision binary32 (* (- (log1p (* (* (+ u -0.25) (+ u -0.25)) (* (+ u -0.25) -2.3703703703703702))) (log1p (* (+ u -0.25) (+ 0.8888888888888888 (* u 1.7777777777777777))))) (* s -3.0)))
float code(float s, float u) {
return (log1pf((((u + -0.25f) * (u + -0.25f)) * ((u + -0.25f) * -2.3703703703703702f))) - log1pf(((u + -0.25f) * (0.8888888888888888f + (u * 1.7777777777777777f))))) * (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(u + Float32(-0.25)) * Float32(-2.3703703703703702)))) - log1p(Float32(Float32(u + Float32(-0.25)) * Float32(Float32(0.8888888888888888) + Float32(u * Float32(1.7777777777777777)))))) * Float32(s * Float32(-3.0))) end
\begin{array}{l}
\\
\left(\mathsf{log1p}\left(\left(\left(u + -0.25\right) \cdot \left(u + -0.25\right)\right) \cdot \left(\left(u + -0.25\right) \cdot -2.3703703703703702\right)\right) - \mathsf{log1p}\left(\left(u + -0.25\right) \cdot \left(0.8888888888888888 + u \cdot 1.7777777777777777\right)\right)\right) \cdot \left(s \cdot -3\right)
\end{array}
Initial program 95.5%
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-eval96.3%
Simplified96.3%
Applied egg-rr98.2%
distribute-rgt-inN/A
*-commutativeN/A
+-commutativeN/A
+-lowering-+.f32N/A
frac-timesN/A
/-lowering-/.f32N/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
metadata-evalN/A
div-invN/A
metadata-evalN/A
associate-*l*N/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
metadata-eval98.3%
Applied egg-rr98.3%
Taylor expanded in s around 0
associate-*r*N/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
--lowering--.f32N/A
Simplified98.3%
Final simplification98.3%
(FPCore (s u) :precision binary32 (* (- (log1p (/ (- (/ u -0.75) -0.3333333333333333) (/ 0.75 (+ u -0.25)))) (log1p (/ (+ u -0.25) 0.75))) (* s -3.0)))
float code(float s, float u) {
return (log1pf((((u / -0.75f) - -0.3333333333333333f) / (0.75f / (u + -0.25f)))) - log1pf(((u + -0.25f) / 0.75f))) * (s * -3.0f);
}
function code(s, u) return Float32(Float32(log1p(Float32(Float32(Float32(u / Float32(-0.75)) - Float32(-0.3333333333333333)) / Float32(Float32(0.75) / Float32(u + Float32(-0.25))))) - log1p(Float32(Float32(u + Float32(-0.25)) / Float32(0.75)))) * Float32(s * Float32(-3.0))) end
\begin{array}{l}
\\
\left(\mathsf{log1p}\left(\frac{\frac{u}{-0.75} - -0.3333333333333333}{\frac{0.75}{u + -0.25}}\right) - \mathsf{log1p}\left(\frac{u + -0.25}{0.75}\right)\right) \cdot \left(s \cdot -3\right)
\end{array}
Initial program 95.5%
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-eval96.3%
Simplified96.3%
+-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-rr98.2%
(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 95.5%
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-eval96.3%
Simplified96.3%
+-commutativeN/A
div-invN/A
fma-defineN/A
fma-lowering-fma.f32N/A
metadata-eval97.9%
Applied egg-rr97.9%
Final simplification97.9%
(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(Float32(s * Float32(-3.0)) * log1p(Float32(u * Float32(Float32(-1.3333333333333333) + Float32(Float32(0.3333333333333333) / u))))) end
\begin{array}{l}
\\
\left(s \cdot -3\right) \cdot \mathsf{log1p}\left(u \cdot \left(-1.3333333333333333 + \frac{0.3333333333333333}{u}\right)\right)
\end{array}
Initial program 95.5%
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-eval96.3%
Simplified96.3%
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%
Final simplification96.9%
(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 95.5%
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-eval96.3%
Simplified96.3%
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-*.f3296.6%
Simplified96.6%
Final simplification96.6%
(FPCore (s u) :precision binary32 (* (* s -3.0) (log1p (+ (/ u -0.75) 0.3333333333333333))))
float code(float s, float u) {
return (s * -3.0f) * log1pf(((u / -0.75f) + 0.3333333333333333f));
}
function code(s, u) return Float32(Float32(s * Float32(-3.0)) * log1p(Float32(Float32(u / Float32(-0.75)) + Float32(0.3333333333333333)))) end
\begin{array}{l}
\\
\left(s \cdot -3\right) \cdot \mathsf{log1p}\left(\frac{u}{-0.75} + 0.3333333333333333\right)
\end{array}
Initial program 95.5%
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-eval96.3%
Simplified96.3%
Final simplification96.3%
(FPCore (s u) :precision binary32 (* (* s -3.0) (log (+ (/ u -0.75) 1.3333333333333333))))
float code(float s, float u) {
return (s * -3.0f) * logf(((u / -0.75f) + 1.3333333333333333f));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = (s * (-3.0e0)) * log(((u / (-0.75e0)) + 1.3333333333333333e0))
end function
function code(s, u) return Float32(Float32(s * Float32(-3.0)) * log(Float32(Float32(u / Float32(-0.75)) + Float32(1.3333333333333333)))) end
function tmp = code(s, u) tmp = (s * single(-3.0)) * log(((u / single(-0.75)) + single(1.3333333333333333))); end
\begin{array}{l}
\\
\left(s \cdot -3\right) \cdot \log \left(\frac{u}{-0.75} + 1.3333333333333333\right)
\end{array}
Initial program 95.5%
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-eval96.3%
Simplified96.3%
+-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-rr94.5%
Final simplification94.5%
(FPCore (s u) :precision binary32 (* 3.0 (* s (+ u (log 0.75)))))
float code(float s, float u) {
return 3.0f * (s * (u + logf(0.75f)));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = 3.0e0 * (s * (u + log(0.75e0)))
end function
function code(s, u) return Float32(Float32(3.0) * Float32(s * Float32(u + log(Float32(0.75))))) end
function tmp = code(s, u) tmp = single(3.0) * (s * (u + log(single(0.75)))); end
\begin{array}{l}
\\
3 \cdot \left(s \cdot \left(u + \log 0.75\right)\right)
\end{array}
Initial program 95.5%
sub-negN/A
+-commutativeN/A
flip-+N/A
sqr-negN/A
/-lowering-/.f32N/A
Applied egg-rr95.2%
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.f3225.7%
Simplified25.7%
(FPCore (s u) :precision binary32 (* (log 0.75) (* s 3.0)))
float code(float s, float u) {
return logf(0.75f) * (s * 3.0f);
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = log(0.75e0) * (s * 3.0e0)
end function
function code(s, u) return Float32(log(Float32(0.75)) * Float32(s * Float32(3.0))) end
function tmp = code(s, u) tmp = log(single(0.75)) * (s * single(3.0)); end
\begin{array}{l}
\\
\log 0.75 \cdot \left(s \cdot 3\right)
\end{array}
Initial program 95.5%
Taylor expanded in u around 0
log-lowering-log.f327.9%
Simplified7.9%
Final simplification7.9%
(FPCore (s u) :precision binary32 (* s (* 3.0 (log 0.75))))
float code(float s, float u) {
return s * (3.0f * logf(0.75f));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = s * (3.0e0 * log(0.75e0))
end function
function code(s, u) return Float32(s * Float32(Float32(3.0) * log(Float32(0.75)))) end
function tmp = code(s, u) tmp = s * (single(3.0) * log(single(0.75))); end
\begin{array}{l}
\\
s \cdot \left(3 \cdot \log 0.75\right)
\end{array}
Initial program 95.5%
Taylor expanded in u around 0
associate-*r*N/A
*-commutativeN/A
associate-*l*N/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
log-lowering-log.f327.9%
Simplified7.9%
herbie shell --seed 2024148
(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))))))