
(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 (- (* (* 3.0 s) (log (- 1.0 (/ (- u 0.25) 0.75))))))
float code(float s, float u) {
return -((3.0f * s) * logf((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 - ((u - 0.25e0) / 0.75e0))))
end function
function code(s, u) return Float32(-Float32(Float32(Float32(3.0) * s) * log(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) - ((u - single(0.25)) / single(0.75))))); end
\begin{array}{l}
\\
-\left(3 \cdot s\right) \cdot \log \left(1 - \frac{u - 0.25}{0.75}\right)
\end{array}
Initial program 95.8%
lift-*.f32N/A
lift-log.f32N/A
log-pow-revN/A
sqr-powN/A
pow-prod-downN/A
log-powN/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-/l*N/A
lower-*.f32N/A
metadata-evalN/A
lower-log.f32N/A
lift-/.f32N/A
inv-powN/A
lift-/.f32N/A
inv-powN/A
Applied rewrites96.4%
lift-*.f32N/A
lift-*.f32N/A
associate-*l*N/A
lift-log.f32N/A
log-pow-revN/A
lift-pow.f32N/A
pow-powN/A
metadata-evalN/A
metadata-evalN/A
pow-powN/A
inv-powN/A
lift--.f32N/A
lift-/.f32N/A
lift--.f32N/A
log-pow-revN/A
Applied rewrites96.7%
(FPCore (s u) :precision binary32 (* (* (+ (log 0.75) u) s) 3.0))
float code(float s, float u) {
return ((logf(0.75f) + u) * s) * 3.0f;
}
real(4) function code(s, u)
real(4), intent (in) :: s
real(4), intent (in) :: u
code = ((log(0.75e0) + u) * s) * 3.0e0
end function
function code(s, u) return Float32(Float32(Float32(log(Float32(0.75)) + u) * s) * Float32(3.0)) end
function tmp = code(s, u) tmp = ((log(single(0.75)) + u) * s) * single(3.0); end
\begin{array}{l}
\\
\left(\left(\log 0.75 + u\right) \cdot s\right) \cdot 3
\end{array}
Initial program 95.8%
Taylor expanded in u around 0
distribute-lft-outN/A
*-commutativeN/A
lower-*.f32N/A
distribute-lft-outN/A
*-commutativeN/A
lower-*.f32N/A
+-commutativeN/A
lower-+.f32N/A
lower-log.f3225.8
Applied rewrites25.8%
(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(Float32(3.0) * s) * log(Float32(0.75))) end
function tmp = code(s, u) tmp = (single(3.0) * s) * log(single(0.75)); end
\begin{array}{l}
\\
\left(3 \cdot s\right) \cdot \log 0.75
\end{array}
Initial program 95.8%
Taylor expanded in u around 0
Applied rewrites7.3%
(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(Float32(log(Float32(0.75)) * s) * Float32(3.0)) end
function tmp = code(s, u) tmp = (log(single(0.75)) * s) * single(3.0); end
\begin{array}{l}
\\
\left(\log 0.75 \cdot s\right) \cdot 3
\end{array}
Initial program 95.8%
Taylor expanded in u around 0
*-commutativeN/A
lower-*.f32N/A
*-commutativeN/A
lower-*.f32N/A
lower-log.f327.3
Applied rewrites7.3%
(FPCore (s u) :precision binary32 (* (* s 1.5) (fma (/ 0.0 0.0) 2.0 (/ 0.0 0.0))))
float code(float s, float u) {
return (s * 1.5f) * fmaf((0.0f / 0.0f), 2.0f, (0.0f / 0.0f));
}
function code(s, u) return Float32(Float32(s * Float32(1.5)) * fma(Float32(Float32(0.0) / Float32(0.0)), Float32(2.0), Float32(Float32(0.0) / Float32(0.0)))) end
\begin{array}{l}
\\
\left(s \cdot 1.5\right) \cdot \mathsf{fma}\left(\frac{0}{0}, 2, \frac{0}{0}\right)
\end{array}
Initial program 95.8%
lift-*.f32N/A
lift-log.f32N/A
log-pow-revN/A
sqr-powN/A
pow-prod-downN/A
log-powN/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-/l*N/A
lower-*.f32N/A
metadata-evalN/A
lower-log.f32N/A
lift-/.f32N/A
inv-powN/A
lift-/.f32N/A
inv-powN/A
Applied rewrites96.4%
Applied rewrites-0.0%
(FPCore (s u) :precision binary32 (* (* s 1.5) (fma 3.0 (/ 0.0 0.0) (/ 0.0 0.0))))
float code(float s, float u) {
return (s * 1.5f) * fmaf(3.0f, (0.0f / 0.0f), (0.0f / 0.0f));
}
function code(s, u) return Float32(Float32(s * Float32(1.5)) * fma(Float32(3.0), Float32(Float32(0.0) / Float32(0.0)), Float32(Float32(0.0) / Float32(0.0)))) end
\begin{array}{l}
\\
\left(s \cdot 1.5\right) \cdot \mathsf{fma}\left(3, \frac{0}{0}, \frac{0}{0}\right)
\end{array}
Initial program 95.8%
lift-*.f32N/A
lift-log.f32N/A
log-pow-revN/A
sqr-powN/A
pow-prod-downN/A
log-powN/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-/l*N/A
lower-*.f32N/A
metadata-evalN/A
lower-log.f32N/A
lift-/.f32N/A
inv-powN/A
lift-/.f32N/A
inv-powN/A
Applied rewrites96.4%
Applied rewrites-0.0%
(FPCore (s u) :precision binary32 (* (* s 1.5) (fma 1.5 (/ 0.0 0.0) (/ 0.0 0.0))))
float code(float s, float u) {
return (s * 1.5f) * fmaf(1.5f, (0.0f / 0.0f), (0.0f / 0.0f));
}
function code(s, u) return Float32(Float32(s * Float32(1.5)) * fma(Float32(1.5), Float32(Float32(0.0) / Float32(0.0)), Float32(Float32(0.0) / Float32(0.0)))) end
\begin{array}{l}
\\
\left(s \cdot 1.5\right) \cdot \mathsf{fma}\left(1.5, \frac{0}{0}, \frac{0}{0}\right)
\end{array}
Initial program 95.8%
lift-*.f32N/A
lift-log.f32N/A
log-pow-revN/A
sqr-powN/A
pow-prod-downN/A
log-powN/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-/l*N/A
lower-*.f32N/A
metadata-evalN/A
lower-log.f32N/A
lift-/.f32N/A
inv-powN/A
lift-/.f32N/A
inv-powN/A
Applied rewrites96.4%
Applied rewrites-0.0%
(FPCore (s u) :precision binary32 (* (* s 1.5) (fma 0.5 (/ 0.0 0.0) (/ 0.0 0.0))))
float code(float s, float u) {
return (s * 1.5f) * fmaf(0.5f, (0.0f / 0.0f), (0.0f / 0.0f));
}
function code(s, u) return Float32(Float32(s * Float32(1.5)) * fma(Float32(0.5), Float32(Float32(0.0) / Float32(0.0)), Float32(Float32(0.0) / Float32(0.0)))) end
\begin{array}{l}
\\
\left(s \cdot 1.5\right) \cdot \mathsf{fma}\left(0.5, \frac{0}{0}, \frac{0}{0}\right)
\end{array}
Initial program 95.8%
lift-*.f32N/A
lift-log.f32N/A
log-pow-revN/A
sqr-powN/A
pow-prod-downN/A
log-powN/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-/l*N/A
lower-*.f32N/A
metadata-evalN/A
lower-log.f32N/A
lift-/.f32N/A
inv-powN/A
lift-/.f32N/A
inv-powN/A
Applied rewrites96.4%
Applied rewrites-0.0%
(FPCore (s u) :precision binary32 (fma (* s 2.0) (/ 0.0 0.0) (* (NAN) s)))
\begin{array}{l}
\\
\mathsf{fma}\left(s \cdot 2, \frac{0}{0}, \mathsf{NAN}\left(\right) \cdot s\right)
\end{array}
Initial program 95.8%
lift-*.f32N/A
lift-log.f32N/A
log-pow-revN/A
sqr-powN/A
pow-prod-downN/A
log-powN/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-/l*N/A
lower-*.f32N/A
metadata-evalN/A
lower-log.f32N/A
lift-/.f32N/A
inv-powN/A
lift-/.f32N/A
inv-powN/A
Applied rewrites96.4%
Applied rewrites-0.0%
Taylor expanded in s around 0
*-commutativeN/A
lower-*.f32N/A
lower-NAN.f32-0.0
Applied rewrites-0.0%
(FPCore (s u) :precision binary32 (fma (* (NAN) s) 1.5 (* (/ 0.0 0.0) s)))
\begin{array}{l}
\\
\mathsf{fma}\left(\mathsf{NAN}\left(\right) \cdot s, 1.5, \frac{0}{0} \cdot s\right)
\end{array}
Initial program 95.8%
lift-*.f32N/A
lift-log.f32N/A
log-pow-revN/A
sqr-powN/A
pow-prod-downN/A
log-powN/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-/l*N/A
lower-*.f32N/A
metadata-evalN/A
lower-log.f32N/A
lift-/.f32N/A
inv-powN/A
lift-/.f32N/A
inv-powN/A
Applied rewrites96.4%
Applied rewrites0.0%
Taylor expanded in s around 0
*-commutativeN/A
lower-*.f32N/A
lower-NAN.f32-0.0
Applied rewrites-0.0%
(FPCore (s u) :precision binary32 (NAN))
\begin{array}{l}
\\
\mathsf{NAN}\left(\right)
\end{array}
Initial program 95.8%
lift-*.f32N/A
lift-log.f32N/A
log-pow-revN/A
sqr-powN/A
pow-prod-downN/A
log-powN/A
lower-*.f32N/A
lift-*.f32N/A
*-commutativeN/A
associate-/l*N/A
lower-*.f32N/A
metadata-evalN/A
lower-log.f32N/A
lift-/.f32N/A
inv-powN/A
lift-/.f32N/A
inv-powN/A
Applied rewrites96.4%
Applied rewrites-0.0%
Taylor expanded in s around 0
lower-NAN.f32-0.0
Applied rewrites-0.0%
herbie shell --seed 2024326
(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))))))