
(FPCore (s u) :precision binary32 (* s (log (/ 1.0 (- 1.0 (* 4.0 u))))))
float code(float s, float u) {
return s * logf((1.0f / (1.0f - (4.0f * u))));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = s * log((1.0e0 / (1.0e0 - (4.0e0 * u))))
end function
function code(s, u) return Float32(s * log(Float32(Float32(1.0) / Float32(Float32(1.0) - Float32(Float32(4.0) * u))))) end
function tmp = code(s, u) tmp = s * log((single(1.0) / (single(1.0) - (single(4.0) * u)))); end
\begin{array}{l}
\\
s \cdot \log \left(\frac{1}{1 - 4 \cdot u}\right)
\end{array}
Sampling outcomes in binary32 precision:
Herbie found 12 alternatives:
| Alternative | Accuracy | Speedup |
|---|
(FPCore (s u) :precision binary32 (* s (log (/ 1.0 (- 1.0 (* 4.0 u))))))
float code(float s, float u) {
return s * logf((1.0f / (1.0f - (4.0f * u))));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = s * log((1.0e0 / (1.0e0 - (4.0e0 * u))))
end function
function code(s, u) return Float32(s * log(Float32(Float32(1.0) / Float32(Float32(1.0) - Float32(Float32(4.0) * u))))) end
function tmp = code(s, u) tmp = s * log((single(1.0) / (single(1.0) - (single(4.0) * u)))); end
\begin{array}{l}
\\
s \cdot \log \left(\frac{1}{1 - 4 \cdot u}\right)
\end{array}
(FPCore (s u) :precision binary32 (* (log1p (* u -4.0)) (- s)))
float code(float s, float u) {
return log1pf((u * -4.0f)) * -s;
}
function code(s, u) return Float32(log1p(Float32(u * Float32(-4.0))) * Float32(-s)) end
\begin{array}{l}
\\
\mathsf{log1p}\left(u \cdot -4\right) \cdot \left(-s\right)
\end{array}
Initial program 59.9%
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
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f32N/A
metadata-evalN/A
*-commutativeN/A
neg-mul-1N/A
neg-lowering-neg.f3299.3%
Simplified99.3%
(FPCore (s u) :precision binary32 (* u (+ (* s 4.0) (* (* u s) (+ (+ 8.0 (* u 21.333333333333332)) (* u (* u 64.0)))))))
float code(float s, float u) {
return u * ((s * 4.0f) + ((u * s) * ((8.0f + (u * 21.333333333333332f)) + (u * (u * 64.0f)))));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = u * ((s * 4.0e0) + ((u * s) * ((8.0e0 + (u * 21.333333333333332e0)) + (u * (u * 64.0e0)))))
end function
function code(s, u) return Float32(u * Float32(Float32(s * Float32(4.0)) + Float32(Float32(u * s) * Float32(Float32(Float32(8.0) + Float32(u * Float32(21.333333333333332))) + Float32(u * Float32(u * Float32(64.0))))))) end
function tmp = code(s, u) tmp = u * ((s * single(4.0)) + ((u * s) * ((single(8.0) + (u * single(21.333333333333332))) + (u * (u * single(64.0)))))); end
\begin{array}{l}
\\
u \cdot \left(s \cdot 4 + \left(u \cdot s\right) \cdot \left(\left(8 + u \cdot 21.333333333333332\right) + u \cdot \left(u \cdot 64\right)\right)\right)
\end{array}
Initial program 59.9%
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
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f32N/A
metadata-evalN/A
*-commutativeN/A
neg-mul-1N/A
neg-lowering-neg.f3299.3%
Simplified99.3%
Taylor expanded in u around 0
*-lowering-*.f32N/A
+-lowering-+.f32N/A
*-lowering-*.f32N/A
distribute-rgt-inN/A
associate-*r*N/A
associate-+r+N/A
distribute-rgt-inN/A
*-commutativeN/A
+-commutativeN/A
distribute-rgt-inN/A
*-commutativeN/A
associate-*r*N/A
associate-*r*N/A
distribute-rgt-outN/A
Simplified93.6%
Final simplification93.6%
(FPCore (s u) :precision binary32 (* u (+ (* s 4.0) (* (* u s) (+ 8.0 (* u (+ 21.333333333333332 (* u 64.0))))))))
float code(float s, float u) {
return u * ((s * 4.0f) + ((u * s) * (8.0f + (u * (21.333333333333332f + (u * 64.0f))))));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = u * ((s * 4.0e0) + ((u * s) * (8.0e0 + (u * (21.333333333333332e0 + (u * 64.0e0))))))
end function
function code(s, u) return Float32(u * Float32(Float32(s * Float32(4.0)) + Float32(Float32(u * s) * Float32(Float32(8.0) + Float32(u * Float32(Float32(21.333333333333332) + Float32(u * Float32(64.0)))))))) end
function tmp = code(s, u) tmp = u * ((s * single(4.0)) + ((u * s) * (single(8.0) + (u * (single(21.333333333333332) + (u * single(64.0))))))); end
\begin{array}{l}
\\
u \cdot \left(s \cdot 4 + \left(u \cdot s\right) \cdot \left(8 + u \cdot \left(21.333333333333332 + u \cdot 64\right)\right)\right)
\end{array}
Initial program 59.9%
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
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f32N/A
metadata-evalN/A
*-commutativeN/A
neg-mul-1N/A
neg-lowering-neg.f3299.3%
Simplified99.3%
Taylor expanded in u around 0
*-lowering-*.f32N/A
+-lowering-+.f32N/A
*-lowering-*.f32N/A
distribute-rgt-inN/A
associate-*r*N/A
associate-+r+N/A
distribute-rgt-inN/A
*-commutativeN/A
+-commutativeN/A
distribute-rgt-inN/A
*-commutativeN/A
associate-*r*N/A
associate-*r*N/A
distribute-rgt-outN/A
Simplified93.6%
+-commutativeN/A
+-lowering-+.f32N/A
*-lowering-*.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
associate-+l+N/A
+-lowering-+.f32N/A
distribute-lft-outN/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
*-lowering-*.f32N/A
*-lowering-*.f3293.6%
Applied egg-rr93.6%
Final simplification93.6%
(FPCore (s u) :precision binary32 (* u (* s (+ 4.0 (* u (+ 8.0 (* u (+ 21.333333333333332 (* u 64.0)))))))))
float code(float s, float u) {
return u * (s * (4.0f + (u * (8.0f + (u * (21.333333333333332f + (u * 64.0f)))))));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = u * (s * (4.0e0 + (u * (8.0e0 + (u * (21.333333333333332e0 + (u * 64.0e0)))))))
end function
function code(s, u) return Float32(u * Float32(s * Float32(Float32(4.0) + Float32(u * Float32(Float32(8.0) + Float32(u * Float32(Float32(21.333333333333332) + Float32(u * Float32(64.0))))))))) end
function tmp = code(s, u) tmp = u * (s * (single(4.0) + (u * (single(8.0) + (u * (single(21.333333333333332) + (u * single(64.0)))))))); end
\begin{array}{l}
\\
u \cdot \left(s \cdot \left(4 + u \cdot \left(8 + u \cdot \left(21.333333333333332 + u \cdot 64\right)\right)\right)\right)
\end{array}
Initial program 59.9%
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
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f32N/A
metadata-evalN/A
*-commutativeN/A
neg-mul-1N/A
neg-lowering-neg.f3299.3%
Simplified99.3%
Taylor expanded in u around 0
*-lowering-*.f32N/A
+-lowering-+.f32N/A
*-lowering-*.f32N/A
distribute-rgt-inN/A
associate-*r*N/A
associate-+r+N/A
distribute-rgt-inN/A
*-commutativeN/A
+-commutativeN/A
distribute-rgt-inN/A
*-commutativeN/A
associate-*r*N/A
associate-*r*N/A
distribute-rgt-outN/A
Simplified93.6%
*-commutativeN/A
*-lowering-*.f32N/A
Applied egg-rr93.5%
Final simplification93.5%
(FPCore (s u) :precision binary32 (* u (+ (* s 4.0) (* (* u s) (+ 8.0 (* u 21.333333333333332))))))
float code(float s, float u) {
return u * ((s * 4.0f) + ((u * s) * (8.0f + (u * 21.333333333333332f))));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = u * ((s * 4.0e0) + ((u * s) * (8.0e0 + (u * 21.333333333333332e0))))
end function
function code(s, u) return Float32(u * Float32(Float32(s * Float32(4.0)) + Float32(Float32(u * s) * Float32(Float32(8.0) + Float32(u * Float32(21.333333333333332)))))) end
function tmp = code(s, u) tmp = u * ((s * single(4.0)) + ((u * s) * (single(8.0) + (u * single(21.333333333333332))))); end
\begin{array}{l}
\\
u \cdot \left(s \cdot 4 + \left(u \cdot s\right) \cdot \left(8 + u \cdot 21.333333333333332\right)\right)
\end{array}
Initial program 59.9%
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
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f32N/A
metadata-evalN/A
*-commutativeN/A
neg-mul-1N/A
neg-lowering-neg.f3299.3%
Simplified99.3%
remove-double-divN/A
remove-double-negN/A
distribute-rgt-neg-inN/A
distribute-lft-neg-inN/A
associate-/r*N/A
clear-numN/A
/-lowering-/.f32N/A
metadata-evalN/A
metadata-evalN/A
associate-*l/N/A
associate-/r/N/A
/-lowering-/.f32N/A
metadata-evalN/A
frac-2negN/A
div-invN/A
metadata-evalN/A
*-rgt-identity99.0%
Applied egg-rr99.0%
Taylor expanded in u around 0
*-lowering-*.f32N/A
+-lowering-+.f32N/A
*-lowering-*.f32N/A
distribute-rgt-inN/A
associate-*r*N/A
*-commutativeN/A
*-commutativeN/A
associate-*l*N/A
distribute-lft-inN/A
*-lowering-*.f32N/A
*-commutativeN/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
*-commutativeN/A
*-lowering-*.f3291.8%
Simplified91.8%
Final simplification91.8%
(FPCore (s u) :precision binary32 (* u (* s (+ 4.0 (* u (+ 8.0 (* u 21.333333333333332)))))))
float code(float s, float u) {
return u * (s * (4.0f + (u * (8.0f + (u * 21.333333333333332f)))));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = u * (s * (4.0e0 + (u * (8.0e0 + (u * 21.333333333333332e0)))))
end function
function code(s, u) return Float32(u * Float32(s * Float32(Float32(4.0) + Float32(u * Float32(Float32(8.0) + Float32(u * Float32(21.333333333333332))))))) end
function tmp = code(s, u) tmp = u * (s * (single(4.0) + (u * (single(8.0) + (u * single(21.333333333333332)))))); end
\begin{array}{l}
\\
u \cdot \left(s \cdot \left(4 + u \cdot \left(8 + u \cdot 21.333333333333332\right)\right)\right)
\end{array}
Initial program 59.9%
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
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f32N/A
metadata-evalN/A
*-commutativeN/A
neg-mul-1N/A
neg-lowering-neg.f3299.3%
Simplified99.3%
Taylor expanded in u around 0
distribute-lft-inN/A
distribute-rgt-inN/A
associate-*r*N/A
distribute-rgt-inN/A
*-commutativeN/A
associate-+r+N/A
+-commutativeN/A
*-commutativeN/A
associate-*l*N/A
*-commutativeN/A
associate-*r*N/A
*-commutativeN/A
distribute-lft-outN/A
*-commutativeN/A
Simplified91.1%
associate-+l+N/A
distribute-rgt-inN/A
associate-*r*N/A
*-commutativeN/A
associate-*l*N/A
distribute-lft-inN/A
associate-*r*N/A
*-commutativeN/A
distribute-rgt-inN/A
*-commutativeN/A
*-lowering-*.f32N/A
Applied egg-rr91.6%
Final simplification91.6%
(FPCore (s u) :precision binary32 (* u (+ (* s 4.0) (* (* u s) 8.0))))
float code(float s, float u) {
return u * ((s * 4.0f) + ((u * s) * 8.0f));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = u * ((s * 4.0e0) + ((u * s) * 8.0e0))
end function
function code(s, u) return Float32(u * Float32(Float32(s * Float32(4.0)) + Float32(Float32(u * s) * Float32(8.0)))) end
function tmp = code(s, u) tmp = u * ((s * single(4.0)) + ((u * s) * single(8.0))); end
\begin{array}{l}
\\
u \cdot \left(s \cdot 4 + \left(u \cdot s\right) \cdot 8\right)
\end{array}
Initial program 59.9%
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
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f32N/A
metadata-evalN/A
*-commutativeN/A
neg-mul-1N/A
neg-lowering-neg.f3299.3%
Simplified99.3%
Taylor expanded in u around 0
*-lowering-*.f32N/A
+-lowering-+.f32N/A
*-lowering-*.f32N/A
distribute-rgt-inN/A
associate-*r*N/A
associate-+r+N/A
distribute-rgt-inN/A
*-commutativeN/A
+-commutativeN/A
distribute-rgt-inN/A
*-commutativeN/A
associate-*r*N/A
associate-*r*N/A
distribute-rgt-outN/A
Simplified93.6%
Taylor expanded in u around 0
Simplified88.0%
Final simplification88.0%
(FPCore (s u) :precision binary32 (* s (- (* u (* u 8.0)) (/ u -0.25))))
float code(float s, float u) {
return s * ((u * (u * 8.0f)) - (u / -0.25f));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = s * ((u * (u * 8.0e0)) - (u / (-0.25e0)))
end function
function code(s, u) return Float32(s * Float32(Float32(u * Float32(u * Float32(8.0))) - Float32(u / Float32(-0.25)))) end
function tmp = code(s, u) tmp = s * ((u * (u * single(8.0))) - (u / single(-0.25))); end
\begin{array}{l}
\\
s \cdot \left(u \cdot \left(u \cdot 8\right) - \frac{u}{-0.25}\right)
\end{array}
Initial program 59.9%
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
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f32N/A
metadata-evalN/A
*-commutativeN/A
neg-mul-1N/A
neg-lowering-neg.f3299.3%
Simplified99.3%
Taylor expanded in u around 0
distribute-rgt-inN/A
associate-*r*N/A
*-commutativeN/A
associate-*r*N/A
distribute-rgt-outN/A
*-commutativeN/A
associate-*l*N/A
+-commutativeN/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
+-commutativeN/A
+-lowering-+.f32N/A
*-commutativeN/A
*-lowering-*.f3287.7%
Simplified87.7%
distribute-lft-inN/A
+-commutativeN/A
cancel-sign-subN/A
remove-double-divN/A
metadata-evalN/A
frac-2negN/A
associate-/r/N/A
clear-numN/A
--lowering--.f32N/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
associate-/r/N/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
metadata-evalN/A
associate-/r/N/A
clear-numN/A
/-lowering-/.f32N/A
metadata-evalN/A
metadata-eval87.9%
Applied egg-rr87.9%
(FPCore (s u) :precision binary32 (* u (* s (+ 4.0 (* u 8.0)))))
float code(float s, float u) {
return u * (s * (4.0f + (u * 8.0f)));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = u * (s * (4.0e0 + (u * 8.0e0)))
end function
function code(s, u) return Float32(u * Float32(s * Float32(Float32(4.0) + Float32(u * Float32(8.0))))) end
function tmp = code(s, u) tmp = u * (s * (single(4.0) + (u * single(8.0)))); end
\begin{array}{l}
\\
u \cdot \left(s \cdot \left(4 + u \cdot 8\right)\right)
\end{array}
Initial program 59.9%
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
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f32N/A
metadata-evalN/A
*-commutativeN/A
neg-mul-1N/A
neg-lowering-neg.f3299.3%
Simplified99.3%
Taylor expanded in u around 0
distribute-rgt-inN/A
associate-*r*N/A
*-commutativeN/A
associate-*r*N/A
distribute-rgt-outN/A
*-commutativeN/A
associate-*l*N/A
+-commutativeN/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
+-commutativeN/A
+-lowering-+.f32N/A
*-commutativeN/A
*-lowering-*.f3287.7%
Simplified87.7%
*-commutativeN/A
associate-*r*N/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
+-lowering-+.f32N/A
*-lowering-*.f3287.8%
Applied egg-rr87.8%
Final simplification87.8%
(FPCore (s u) :precision binary32 (* s (* u (+ 4.0 (* u 8.0)))))
float code(float s, float u) {
return s * (u * (4.0f + (u * 8.0f)));
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = s * (u * (4.0e0 + (u * 8.0e0)))
end function
function code(s, u) return Float32(s * Float32(u * Float32(Float32(4.0) + Float32(u * Float32(8.0))))) end
function tmp = code(s, u) tmp = s * (u * (single(4.0) + (u * single(8.0)))); end
\begin{array}{l}
\\
s \cdot \left(u \cdot \left(4 + u \cdot 8\right)\right)
\end{array}
Initial program 59.9%
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
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f32N/A
metadata-evalN/A
*-commutativeN/A
neg-mul-1N/A
neg-lowering-neg.f3299.3%
Simplified99.3%
Taylor expanded in u around 0
distribute-rgt-inN/A
associate-*r*N/A
*-commutativeN/A
associate-*r*N/A
distribute-rgt-outN/A
*-commutativeN/A
associate-*l*N/A
+-commutativeN/A
*-lowering-*.f32N/A
*-lowering-*.f32N/A
+-commutativeN/A
+-lowering-+.f32N/A
*-commutativeN/A
*-lowering-*.f3287.7%
Simplified87.7%
(FPCore (s u) :precision binary32 (* s (/ u 0.25)))
float code(float s, float u) {
return s * (u / 0.25f);
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = s * (u / 0.25e0)
end function
function code(s, u) return Float32(s * Float32(u / Float32(0.25))) end
function tmp = code(s, u) tmp = s * (u / single(0.25)); end
\begin{array}{l}
\\
s \cdot \frac{u}{0.25}
\end{array}
Initial program 59.9%
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
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f32N/A
metadata-evalN/A
*-commutativeN/A
neg-mul-1N/A
neg-lowering-neg.f3299.3%
Simplified99.3%
Taylor expanded in u around 0
*-lowering-*.f32N/A
*-lowering-*.f3274.8%
Simplified74.8%
*-commutativeN/A
associate-*r*N/A
*-lowering-*.f32N/A
*-commutativeN/A
metadata-evalN/A
metadata-evalN/A
div-invN/A
/-lowering-/.f32N/A
metadata-eval75.0%
Applied egg-rr75.0%
Final simplification75.0%
(FPCore (s u) :precision binary32 (* 4.0 (* u s)))
float code(float s, float u) {
return 4.0f * (u * s);
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = 4.0e0 * (u * s)
end function
function code(s, u) return Float32(Float32(4.0) * Float32(u * s)) end
function tmp = code(s, u) tmp = single(4.0) * (u * s); end
\begin{array}{l}
\\
4 \cdot \left(u \cdot s\right)
\end{array}
Initial program 59.9%
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
*-commutativeN/A
distribute-rgt-neg-inN/A
*-lowering-*.f32N/A
metadata-evalN/A
*-commutativeN/A
neg-mul-1N/A
neg-lowering-neg.f3299.3%
Simplified99.3%
Taylor expanded in u around 0
*-lowering-*.f32N/A
*-lowering-*.f3274.8%
Simplified74.8%
Final simplification74.8%
herbie shell --seed 2024164
(FPCore (s u)
:name "Disney BSSRDF, sample scattering profile, lower"
:precision binary32
:pre (and (and (<= 0.0 s) (<= s 256.0)) (and (<= 2.328306437e-10 u) (<= u 0.25)))
(* s (log (/ 1.0 (- 1.0 (* 4.0 u))))))