Disney BSSRDF, sample scattering profile, upper

Percentage Accurate: 95.9% → 95.9%
Time: 9.8s
Alternatives: 9
Speedup: 1.0×

Specification

?
\[\left(0 \leq s \land s \leq 256\right) \land \left(0.25 \leq u \land u \leq 1\right)\]
\[\begin{array}{l} \\ \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \end{array} \]
(FPCore (s u)
 :precision binary32
 (* (* 3.0 s) (log (/ 1.0 (- 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:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 9 alternatives:

AlternativeAccuracySpeedup
The accuracy (vertical axis) and speed (horizontal axis) of each alternatives. Up and to the right is better. The red square shows the initial program, and each blue circle shows an alternative.The line shows the best available speed-accuracy tradeoffs.

Initial Program: 95.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \end{array} \]
(FPCore (s u)
 :precision binary32
 (* (* 3.0 s) (log (/ 1.0 (- 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}

Alternative 1: 95.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \cdot \left(s \cdot 3\right) \end{array} \]
(FPCore (s u)
 :precision binary32
 (* (log (/ 1.0 (- 1.0 (/ (- u 0.25) 0.75)))) (* s 3.0)))
float code(float s, float u) {
	return logf((1.0f / (1.0f - ((u - 0.25f) / 0.75f)))) * (s * 3.0f);
}
real(4) function code(s, u)
    real(4), intent (in) :: s
    real(4), intent (in) :: u
    code = log((1.0e0 / (1.0e0 - ((u - 0.25e0) / 0.75e0)))) * (s * 3.0e0)
end function
function code(s, u)
	return Float32(log(Float32(Float32(1.0) / Float32(Float32(1.0) - Float32(Float32(u - Float32(0.25)) / Float32(0.75))))) * Float32(s * Float32(3.0)))
end
function tmp = code(s, u)
	tmp = log((single(1.0) / (single(1.0) - ((u - single(0.25)) / single(0.75))))) * (s * single(3.0));
end
\begin{array}{l}

\\
\log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \cdot \left(s \cdot 3\right)
\end{array}
Derivation
  1. Initial program 96.1%

    \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
  2. Add Preprocessing
  3. Final simplification96.1%

    \[\leadsto \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \cdot \left(s \cdot 3\right) \]
  4. Add Preprocessing

Alternative 2: 95.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \log \left(\frac{1}{-1.3333333333333333 \cdot \left(u - 0.25\right) + 1}\right) \cdot \left(s \cdot 3\right) \end{array} \]
(FPCore (s u)
 :precision binary32
 (* (log (/ 1.0 (+ (* -1.3333333333333333 (- u 0.25)) 1.0))) (* s 3.0)))
float code(float s, float u) {
	return logf((1.0f / ((-1.3333333333333333f * (u - 0.25f)) + 1.0f))) * (s * 3.0f);
}
real(4) function code(s, u)
    real(4), intent (in) :: s
    real(4), intent (in) :: u
    code = log((1.0e0 / (((-1.3333333333333333e0) * (u - 0.25e0)) + 1.0e0))) * (s * 3.0e0)
end function
function code(s, u)
	return Float32(log(Float32(Float32(1.0) / Float32(Float32(Float32(-1.3333333333333333) * Float32(u - Float32(0.25))) + Float32(1.0)))) * Float32(s * Float32(3.0)))
end
function tmp = code(s, u)
	tmp = log((single(1.0) / ((single(-1.3333333333333333) * (u - single(0.25))) + single(1.0)))) * (s * single(3.0));
end
\begin{array}{l}

\\
\log \left(\frac{1}{-1.3333333333333333 \cdot \left(u - 0.25\right) + 1}\right) \cdot \left(s \cdot 3\right)
\end{array}
Derivation
  1. Initial program 96.1%

    \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift--.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}}\right) \]
    2. sub-negN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{1 + \left(\mathsf{neg}\left(\frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right)}}\right) \]
    3. +-commutativeN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\left(\mathsf{neg}\left(\frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) + 1}}\right) \]
    4. lower-+.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\left(\mathsf{neg}\left(\frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) + 1}}\right) \]
    5. lift-/.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\left(\mathsf{neg}\left(\color{blue}{\frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) + 1}\right) \]
    6. distribute-neg-frac2N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\frac{u - \frac{1}{4}}{\mathsf{neg}\left(\frac{3}{4}\right)}} + 1}\right) \]
    7. div-invN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\left(u - \frac{1}{4}\right) \cdot \frac{1}{\mathsf{neg}\left(\frac{3}{4}\right)}} + 1}\right) \]
    8. *-commutativeN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\frac{1}{\mathsf{neg}\left(\frac{3}{4}\right)} \cdot \left(u - \frac{1}{4}\right)} + 1}\right) \]
    9. lower-*.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\frac{1}{\mathsf{neg}\left(\frac{3}{4}\right)} \cdot \left(u - \frac{1}{4}\right)} + 1}\right) \]
    10. metadata-evalN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\frac{1}{\color{blue}{\frac{-3}{4}}} \cdot \left(u - \frac{1}{4}\right) + 1}\right) \]
    11. metadata-eval96.1

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{-1.3333333333333333} \cdot \left(u - 0.25\right) + 1}\right) \]
  4. Applied rewrites96.1%

    \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{-1.3333333333333333 \cdot \left(u - 0.25\right) + 1}}\right) \]
  5. Final simplification96.1%

    \[\leadsto \log \left(\frac{1}{-1.3333333333333333 \cdot \left(u - 0.25\right) + 1}\right) \cdot \left(s \cdot 3\right) \]
  6. Add Preprocessing

Alternative 3: 95.5% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \log \left(\frac{1}{1.3333333333333333 - 1.3333333333333333 \cdot u}\right) \cdot \left(s \cdot 3\right) \end{array} \]
(FPCore (s u)
 :precision binary32
 (* (log (/ 1.0 (- 1.3333333333333333 (* 1.3333333333333333 u)))) (* s 3.0)))
float code(float s, float u) {
	return logf((1.0f / (1.3333333333333333f - (1.3333333333333333f * u)))) * (s * 3.0f);
}
real(4) function code(s, u)
    real(4), intent (in) :: s
    real(4), intent (in) :: u
    code = log((1.0e0 / (1.3333333333333333e0 - (1.3333333333333333e0 * u)))) * (s * 3.0e0)
end function
function code(s, u)
	return Float32(log(Float32(Float32(1.0) / Float32(Float32(1.3333333333333333) - Float32(Float32(1.3333333333333333) * u)))) * Float32(s * Float32(3.0)))
end
function tmp = code(s, u)
	tmp = log((single(1.0) / (single(1.3333333333333333) - (single(1.3333333333333333) * u)))) * (s * single(3.0));
end
\begin{array}{l}

\\
\log \left(\frac{1}{1.3333333333333333 - 1.3333333333333333 \cdot u}\right) \cdot \left(s \cdot 3\right)
\end{array}
Derivation
  1. Initial program 96.1%

    \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift--.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}}\right) \]
    2. sub-negN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{1 + \left(\mathsf{neg}\left(\frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right)}}\right) \]
    3. +-commutativeN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\left(\mathsf{neg}\left(\frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) + 1}}\right) \]
    4. lower-+.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\left(\mathsf{neg}\left(\frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) + 1}}\right) \]
    5. lift-/.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\left(\mathsf{neg}\left(\color{blue}{\frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) + 1}\right) \]
    6. distribute-neg-frac2N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\frac{u - \frac{1}{4}}{\mathsf{neg}\left(\frac{3}{4}\right)}} + 1}\right) \]
    7. div-invN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\left(u - \frac{1}{4}\right) \cdot \frac{1}{\mathsf{neg}\left(\frac{3}{4}\right)}} + 1}\right) \]
    8. *-commutativeN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\frac{1}{\mathsf{neg}\left(\frac{3}{4}\right)} \cdot \left(u - \frac{1}{4}\right)} + 1}\right) \]
    9. lower-*.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\frac{1}{\mathsf{neg}\left(\frac{3}{4}\right)} \cdot \left(u - \frac{1}{4}\right)} + 1}\right) \]
    10. metadata-evalN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\frac{1}{\color{blue}{\frac{-3}{4}}} \cdot \left(u - \frac{1}{4}\right) + 1}\right) \]
    11. metadata-eval96.1

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{-1.3333333333333333} \cdot \left(u - 0.25\right) + 1}\right) \]
  4. Applied rewrites96.1%

    \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{-1.3333333333333333 \cdot \left(u - 0.25\right) + 1}}\right) \]
  5. Step-by-step derivation
    1. lift-*.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\frac{-4}{3} \cdot \left(u - \frac{1}{4}\right)} + 1}\right) \]
    2. *-commutativeN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\left(u - \frac{1}{4}\right) \cdot \frac{-4}{3}} + 1}\right) \]
    3. metadata-evalN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\left(u - \frac{1}{4}\right) \cdot \color{blue}{\left(\mathsf{neg}\left(\frac{4}{3}\right)\right)} + 1}\right) \]
    4. metadata-evalN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\left(u - \frac{1}{4}\right) \cdot \left(\mathsf{neg}\left(\color{blue}{\frac{1}{\frac{3}{4}}}\right)\right) + 1}\right) \]
    5. distribute-rgt-neg-inN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\left(\mathsf{neg}\left(\left(u - \frac{1}{4}\right) \cdot \frac{1}{\frac{3}{4}}\right)\right)} + 1}\right) \]
    6. div-invN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\left(\mathsf{neg}\left(\color{blue}{\frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) + 1}\right) \]
    7. clear-numN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\left(\mathsf{neg}\left(\color{blue}{\frac{1}{\frac{\frac{3}{4}}{u - \frac{1}{4}}}}\right)\right) + 1}\right) \]
    8. distribute-neg-fracN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\frac{\mathsf{neg}\left(1\right)}{\frac{\frac{3}{4}}{u - \frac{1}{4}}}} + 1}\right) \]
    9. metadata-evalN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\frac{\color{blue}{-1}}{\frac{\frac{3}{4}}{u - \frac{1}{4}}} + 1}\right) \]
    10. lower-/.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\frac{-1}{\frac{\frac{3}{4}}{u - \frac{1}{4}}}} + 1}\right) \]
    11. lower-/.f3295.9

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\frac{-1}{\color{blue}{\frac{0.75}{u - 0.25}}} + 1}\right) \]
  6. Applied rewrites95.9%

    \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\frac{-1}{\frac{0.75}{u - 0.25}}} + 1}\right) \]
  7. Step-by-step derivation
    1. lift-+.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\frac{-1}{\frac{\frac{3}{4}}{u - \frac{1}{4}}} + 1}}\right) \]
    2. +-commutativeN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{1 + \frac{-1}{\frac{\frac{3}{4}}{u - \frac{1}{4}}}}}\right) \]
    3. lift-/.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 + \color{blue}{\frac{-1}{\frac{\frac{3}{4}}{u - \frac{1}{4}}}}}\right) \]
    4. div-invN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 + \color{blue}{-1 \cdot \frac{1}{\frac{\frac{3}{4}}{u - \frac{1}{4}}}}}\right) \]
    5. lift--.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 + -1 \cdot \frac{1}{\frac{\frac{3}{4}}{\color{blue}{u - \frac{1}{4}}}}}\right) \]
    6. lift-/.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 + -1 \cdot \frac{1}{\color{blue}{\frac{\frac{3}{4}}{u - \frac{1}{4}}}}}\right) \]
    7. clear-numN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 + -1 \cdot \color{blue}{\frac{u - \frac{1}{4}}{\frac{3}{4}}}}\right) \]
    8. neg-mul-1N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 + \color{blue}{\left(\mathsf{neg}\left(\frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right)}}\right) \]
    9. sub-negN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}}\right) \]
    10. div-subN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \color{blue}{\left(\frac{u}{\frac{3}{4}} - \frac{\frac{1}{4}}{\frac{3}{4}}\right)}}\right) \]
    11. div-invN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \left(\color{blue}{u \cdot \frac{1}{\frac{3}{4}}} - \frac{\frac{1}{4}}{\frac{3}{4}}\right)}\right) \]
    12. metadata-evalN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \left(u \cdot \color{blue}{\frac{4}{3}} - \frac{\frac{1}{4}}{\frac{3}{4}}\right)}\right) \]
    13. metadata-evalN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \left(u \cdot \frac{4}{3} - \color{blue}{\frac{1}{3}}\right)}\right) \]
    14. sub-negN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \color{blue}{\left(u \cdot \frac{4}{3} + \left(\mathsf{neg}\left(\frac{1}{3}\right)\right)\right)}}\right) \]
    15. metadata-evalN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \left(u \cdot \frac{4}{3} + \color{blue}{\frac{-1}{3}}\right)}\right) \]
    16. +-commutativeN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \color{blue}{\left(\frac{-1}{3} + u \cdot \frac{4}{3}\right)}}\right) \]
    17. associate--r+N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\left(1 - \frac{-1}{3}\right) - u \cdot \frac{4}{3}}}\right) \]
    18. metadata-evalN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\frac{4}{3}} - u \cdot \frac{4}{3}}\right) \]
    19. lower--.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{\frac{4}{3} - u \cdot \frac{4}{3}}}\right) \]
    20. *-commutativeN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\frac{4}{3} - \color{blue}{\frac{4}{3} \cdot u}}\right) \]
    21. lower-*.f3295.5

      \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1.3333333333333333 - \color{blue}{1.3333333333333333 \cdot u}}\right) \]
  8. Applied rewrites95.5%

    \[\leadsto \left(3 \cdot s\right) \cdot \log \left(\frac{1}{\color{blue}{1.3333333333333333 - 1.3333333333333333 \cdot u}}\right) \]
  9. Final simplification95.5%

    \[\leadsto \log \left(\frac{1}{1.3333333333333333 - 1.3333333333333333 \cdot u}\right) \cdot \left(s \cdot 3\right) \]
  10. Add Preprocessing

Alternative 4: 9.5% accurate, 1.1× speedup?

\[\begin{array}{l} \\ \left(\mathsf{log1p}\left(-1.3333333333333333 \cdot \left(u - 0.25\right)\right) \cdot \left(-s\right)\right) \cdot 3 \end{array} \]
(FPCore (s u)
 :precision binary32
 (* (* (log1p (* -1.3333333333333333 (- u 0.25))) (- s)) 3.0))
float code(float s, float u) {
	return (log1pf((-1.3333333333333333f * (u - 0.25f))) * -s) * 3.0f;
}
function code(s, u)
	return Float32(Float32(log1p(Float32(Float32(-1.3333333333333333) * Float32(u - Float32(0.25)))) * Float32(-s)) * Float32(3.0))
end
\begin{array}{l}

\\
\left(\mathsf{log1p}\left(-1.3333333333333333 \cdot \left(u - 0.25\right)\right) \cdot \left(-s\right)\right) \cdot 3
\end{array}
Derivation
  1. Initial program 96.1%

    \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f32N/A

      \[\leadsto \color{blue}{\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)} \]
    2. lift-*.f32N/A

      \[\leadsto \color{blue}{\left(3 \cdot s\right)} \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right) \]
    3. associate-*l*N/A

      \[\leadsto \color{blue}{3 \cdot \left(s \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)} \]
    4. *-commutativeN/A

      \[\leadsto \color{blue}{\left(s \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \cdot 3} \]
    5. lower-*.f32N/A

      \[\leadsto \color{blue}{\left(s \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \cdot 3} \]
  4. Applied rewrites9.4%

    \[\leadsto \color{blue}{\left(\left(-s\right) \cdot \mathsf{log1p}\left(-1.3333333333333333 \cdot \left(u - 0.25\right)\right)\right) \cdot 3} \]
  5. Final simplification9.4%

    \[\leadsto \left(\mathsf{log1p}\left(-1.3333333333333333 \cdot \left(u - 0.25\right)\right) \cdot \left(-s\right)\right) \cdot 3 \]
  6. Add Preprocessing

Alternative 5: 9.5% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \left(-3 \cdot \mathsf{log1p}\left(-1.3333333333333333 \cdot \left(u - 0.25\right)\right)\right) \cdot s \end{array} \]
(FPCore (s u)
 :precision binary32
 (* (* -3.0 (log1p (* -1.3333333333333333 (- u 0.25)))) s))
float code(float s, float u) {
	return (-3.0f * log1pf((-1.3333333333333333f * (u - 0.25f)))) * s;
}
function code(s, u)
	return Float32(Float32(Float32(-3.0) * log1p(Float32(Float32(-1.3333333333333333) * Float32(u - Float32(0.25))))) * s)
end
\begin{array}{l}

\\
\left(-3 \cdot \mathsf{log1p}\left(-1.3333333333333333 \cdot \left(u - 0.25\right)\right)\right) \cdot s
\end{array}
Derivation
  1. Initial program 96.1%

    \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f32N/A

      \[\leadsto \color{blue}{\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)} \]
    2. lift-*.f32N/A

      \[\leadsto \color{blue}{\left(3 \cdot s\right)} \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right) \]
    3. associate-*l*N/A

      \[\leadsto \color{blue}{3 \cdot \left(s \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)} \]
    4. *-commutativeN/A

      \[\leadsto 3 \cdot \color{blue}{\left(\log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right) \cdot s\right)} \]
    5. associate-*r*N/A

      \[\leadsto \color{blue}{\left(3 \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \cdot s} \]
    6. lower-*.f32N/A

      \[\leadsto \color{blue}{\left(3 \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \cdot s} \]
  4. Applied rewrites9.3%

    \[\leadsto \color{blue}{\left(-3 \cdot \mathsf{log1p}\left(-1.3333333333333333 \cdot \left(u - 0.25\right)\right)\right) \cdot s} \]
  5. Add Preprocessing

Alternative 6: 28.1% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \left(\log 0.6666666666666666 \cdot s\right) \cdot -3 \end{array} \]
(FPCore (s u) :precision binary32 (* (* (log 0.6666666666666666) s) -3.0))
float code(float s, float u) {
	return (logf(0.6666666666666666f) * s) * -3.0f;
}
real(4) function code(s, u)
    real(4), intent (in) :: s
    real(4), intent (in) :: u
    code = (log(0.6666666666666666e0) * s) * (-3.0e0)
end function
function code(s, u)
	return Float32(Float32(log(Float32(0.6666666666666666)) * s) * Float32(-3.0))
end
function tmp = code(s, u)
	tmp = (log(single(0.6666666666666666)) * s) * single(-3.0);
end
\begin{array}{l}

\\
\left(\log 0.6666666666666666 \cdot s\right) \cdot -3
\end{array}
Derivation
  1. Initial program 96.1%

    \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f32N/A

      \[\leadsto \color{blue}{\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)} \]
    2. +-lft-identityN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \color{blue}{\left(0 + \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)} \]
    3. metadata-evalN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\color{blue}{\log 1} + \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
    4. distribute-lft-inN/A

      \[\leadsto \color{blue}{\left(3 \cdot s\right) \cdot \log 1 + \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)} \]
    5. lift-*.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log 1 + \color{blue}{\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)} \]
    6. lower-fma.f32N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(3 \cdot s, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)} \]
    7. lift-*.f32N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{3 \cdot s}, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
    8. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{s \cdot 3}, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
    9. lower-*.f32N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{s \cdot 3}, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
    10. metadata-eval7.4

      \[\leadsto \mathsf{fma}\left(s \cdot 3, \color{blue}{0}, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right)\right) \]
    11. lift-*.f32N/A

      \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}\right) \]
    12. lift-*.f32N/A

      \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot s\right)} \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
    13. associate-*l*N/A

      \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{3 \cdot \left(s \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)}\right) \]
    14. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, 3 \cdot \color{blue}{\left(\log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right) \cdot s\right)}\right) \]
    15. associate-*r*N/A

      \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \cdot s}\right) \]
    16. lower-*.f32N/A

      \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \cdot s}\right) \]
  4. Applied rewrites33.1%

    \[\leadsto \color{blue}{\mathsf{fma}\left(s \cdot 3, 0, \left(-3 \cdot \mathsf{log1p}\left(-1.3333333333333333 \cdot \left(u - 0.25\right)\right)\right) \cdot s\right)} \]
  5. Applied rewrites10.6%

    \[\leadsto \color{blue}{\mathsf{fma}\left(s, \mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) \cdot -3, 0\right)} \]
  6. Taylor expanded in u around 0

    \[\leadsto \color{blue}{-3 \cdot \left(s \cdot \log \frac{2}{3}\right)} \]
  7. Step-by-step derivation
    1. *-commutativeN/A

      \[\leadsto \color{blue}{\left(s \cdot \log \frac{2}{3}\right) \cdot -3} \]
    2. lower-*.f32N/A

      \[\leadsto \color{blue}{\left(s \cdot \log \frac{2}{3}\right) \cdot -3} \]
    3. *-commutativeN/A

      \[\leadsto \color{blue}{\left(\log \frac{2}{3} \cdot s\right)} \cdot -3 \]
    4. lower-*.f32N/A

      \[\leadsto \color{blue}{\left(\log \frac{2}{3} \cdot s\right)} \cdot -3 \]
    5. lower-log.f3227.8

      \[\leadsto \left(\color{blue}{\log 0.6666666666666666} \cdot s\right) \cdot -3 \]
  8. Applied rewrites27.8%

    \[\leadsto \color{blue}{\left(\log 0.6666666666666666 \cdot s\right) \cdot -3} \]
  9. Add Preprocessing

Alternative 7: 26.4% accurate, 8.7× speedup?

\[\begin{array}{l} \\ \left(\left(u \cdot s\right) \cdot u\right) \cdot 1.5 \end{array} \]
(FPCore (s u) :precision binary32 (* (* (* u s) u) 1.5))
float code(float s, float u) {
	return ((u * s) * u) * 1.5f;
}
real(4) function code(s, u)
    real(4), intent (in) :: s
    real(4), intent (in) :: u
    code = ((u * s) * u) * 1.5e0
end function
function code(s, u)
	return Float32(Float32(Float32(u * s) * u) * Float32(1.5))
end
function tmp = code(s, u)
	tmp = ((u * s) * u) * single(1.5);
end
\begin{array}{l}

\\
\left(\left(u \cdot s\right) \cdot u\right) \cdot 1.5
\end{array}
Derivation
  1. Initial program 96.1%

    \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-*.f32N/A

      \[\leadsto \color{blue}{\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)} \]
    2. +-lft-identityN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \color{blue}{\left(0 + \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)} \]
    3. metadata-evalN/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\color{blue}{\log 1} + \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
    4. distribute-lft-inN/A

      \[\leadsto \color{blue}{\left(3 \cdot s\right) \cdot \log 1 + \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)} \]
    5. lift-*.f32N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \log 1 + \color{blue}{\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)} \]
    6. lower-fma.f32N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(3 \cdot s, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)} \]
    7. lift-*.f32N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{3 \cdot s}, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
    8. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{s \cdot 3}, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
    9. lower-*.f32N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{s \cdot 3}, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
    10. metadata-eval7.7

      \[\leadsto \mathsf{fma}\left(s \cdot 3, \color{blue}{0}, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right)\right) \]
    11. lift-*.f32N/A

      \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}\right) \]
    12. lift-*.f32N/A

      \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot s\right)} \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
    13. associate-*l*N/A

      \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{3 \cdot \left(s \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)}\right) \]
    14. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, 3 \cdot \color{blue}{\left(\log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right) \cdot s\right)}\right) \]
    15. associate-*r*N/A

      \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \cdot s}\right) \]
    16. lower-*.f32N/A

      \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \cdot s}\right) \]
  4. Applied rewrites33.1%

    \[\leadsto \color{blue}{\mathsf{fma}\left(s \cdot 3, 0, \left(-3 \cdot \mathsf{log1p}\left(-1.3333333333333333 \cdot \left(u - 0.25\right)\right)\right) \cdot s\right)} \]
  5. Taylor expanded in u around 0

    \[\leadsto \color{blue}{-3 \cdot \left(s \cdot \log \frac{4}{3}\right) + u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right)} \]
  6. Step-by-step derivation
    1. associate-*r*N/A

      \[\leadsto \color{blue}{\left(-3 \cdot s\right) \cdot \log \frac{4}{3}} + u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right) \]
    2. lower-fma.f32N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right)\right)} \]
    3. lower-*.f32N/A

      \[\leadsto \mathsf{fma}\left(\color{blue}{-3 \cdot s}, \log \frac{4}{3}, u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right)\right) \]
    4. lower-log.f32N/A

      \[\leadsto \mathsf{fma}\left(-3 \cdot s, \color{blue}{\log \frac{4}{3}}, u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right)\right) \]
    5. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \color{blue}{\left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right) \cdot u}\right) \]
    6. lower-*.f32N/A

      \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \color{blue}{\left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right) \cdot u}\right) \]
    7. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(\color{blue}{\left(s \cdot u\right) \cdot \frac{3}{2}} + 3 \cdot s\right) \cdot u\right) \]
    8. associate-*l*N/A

      \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(\color{blue}{s \cdot \left(u \cdot \frac{3}{2}\right)} + 3 \cdot s\right) \cdot u\right) \]
    9. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(s \cdot \color{blue}{\left(\frac{3}{2} \cdot u\right)} + 3 \cdot s\right) \cdot u\right) \]
    10. *-commutativeN/A

      \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(s \cdot \left(\frac{3}{2} \cdot u\right) + \color{blue}{s \cdot 3}\right) \cdot u\right) \]
    11. distribute-lft-outN/A

      \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \color{blue}{\left(s \cdot \left(\frac{3}{2} \cdot u + 3\right)\right)} \cdot u\right) \]
    12. +-commutativeN/A

      \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(s \cdot \color{blue}{\left(3 + \frac{3}{2} \cdot u\right)}\right) \cdot u\right) \]
    13. lower-*.f32N/A

      \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \color{blue}{\left(s \cdot \left(3 + \frac{3}{2} \cdot u\right)\right)} \cdot u\right) \]
    14. +-commutativeN/A

      \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(s \cdot \color{blue}{\left(\frac{3}{2} \cdot u + 3\right)}\right) \cdot u\right) \]
    15. lower-fma.f327.1

      \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log 1.3333333333333333, \left(s \cdot \color{blue}{\mathsf{fma}\left(1.5, u, 3\right)}\right) \cdot u\right) \]
  7. Applied rewrites7.1%

    \[\leadsto \color{blue}{\mathsf{fma}\left(-3 \cdot s, \log 1.3333333333333333, \left(s \cdot \mathsf{fma}\left(1.5, u, 3\right)\right) \cdot u\right)} \]
  8. Taylor expanded in u around inf

    \[\leadsto \frac{3}{2} \cdot \color{blue}{\left(s \cdot {u}^{2}\right)} \]
  9. Step-by-step derivation
    1. Applied rewrites26.1%

      \[\leadsto \left(\left(u \cdot u\right) \cdot s\right) \cdot \color{blue}{1.5} \]
    2. Step-by-step derivation
      1. Applied rewrites26.1%

        \[\leadsto \left(\left(u \cdot s\right) \cdot u\right) \cdot 1.5 \]
      2. Add Preprocessing

      Alternative 8: 26.4% accurate, 8.7× speedup?

      \[\begin{array}{l} \\ \left(1.5 \cdot u\right) \cdot \left(u \cdot s\right) \end{array} \]
      (FPCore (s u) :precision binary32 (* (* 1.5 u) (* u s)))
      float code(float s, float u) {
      	return (1.5f * u) * (u * s);
      }
      
      real(4) function code(s, u)
          real(4), intent (in) :: s
          real(4), intent (in) :: u
          code = (1.5e0 * u) * (u * s)
      end function
      
      function code(s, u)
      	return Float32(Float32(Float32(1.5) * u) * Float32(u * s))
      end
      
      function tmp = code(s, u)
      	tmp = (single(1.5) * u) * (u * s);
      end
      
      \begin{array}{l}
      
      \\
      \left(1.5 \cdot u\right) \cdot \left(u \cdot s\right)
      \end{array}
      
      Derivation
      1. Initial program 96.1%

        \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift-*.f32N/A

          \[\leadsto \color{blue}{\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)} \]
        2. +-lft-identityN/A

          \[\leadsto \left(3 \cdot s\right) \cdot \color{blue}{\left(0 + \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)} \]
        3. metadata-evalN/A

          \[\leadsto \left(3 \cdot s\right) \cdot \left(\color{blue}{\log 1} + \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
        4. distribute-lft-inN/A

          \[\leadsto \color{blue}{\left(3 \cdot s\right) \cdot \log 1 + \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)} \]
        5. lift-*.f32N/A

          \[\leadsto \left(3 \cdot s\right) \cdot \log 1 + \color{blue}{\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)} \]
        6. lower-fma.f32N/A

          \[\leadsto \color{blue}{\mathsf{fma}\left(3 \cdot s, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)} \]
        7. lift-*.f32N/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{3 \cdot s}, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
        8. *-commutativeN/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{s \cdot 3}, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
        9. lower-*.f32N/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{s \cdot 3}, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
        10. metadata-eval7.4

          \[\leadsto \mathsf{fma}\left(s \cdot 3, \color{blue}{0}, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right)\right) \]
        11. lift-*.f32N/A

          \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}\right) \]
        12. lift-*.f32N/A

          \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot s\right)} \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
        13. associate-*l*N/A

          \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{3 \cdot \left(s \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)}\right) \]
        14. *-commutativeN/A

          \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, 3 \cdot \color{blue}{\left(\log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right) \cdot s\right)}\right) \]
        15. associate-*r*N/A

          \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \cdot s}\right) \]
        16. lower-*.f32N/A

          \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \cdot s}\right) \]
      4. Applied rewrites33.1%

        \[\leadsto \color{blue}{\mathsf{fma}\left(s \cdot 3, 0, \left(-3 \cdot \mathsf{log1p}\left(-1.3333333333333333 \cdot \left(u - 0.25\right)\right)\right) \cdot s\right)} \]
      5. Taylor expanded in u around 0

        \[\leadsto \color{blue}{-3 \cdot \left(s \cdot \log \frac{4}{3}\right) + u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right)} \]
      6. Step-by-step derivation
        1. associate-*r*N/A

          \[\leadsto \color{blue}{\left(-3 \cdot s\right) \cdot \log \frac{4}{3}} + u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right) \]
        2. lower-fma.f32N/A

          \[\leadsto \color{blue}{\mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right)\right)} \]
        3. lower-*.f32N/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{-3 \cdot s}, \log \frac{4}{3}, u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right)\right) \]
        4. lower-log.f32N/A

          \[\leadsto \mathsf{fma}\left(-3 \cdot s, \color{blue}{\log \frac{4}{3}}, u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right)\right) \]
        5. *-commutativeN/A

          \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \color{blue}{\left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right) \cdot u}\right) \]
        6. lower-*.f32N/A

          \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \color{blue}{\left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right) \cdot u}\right) \]
        7. *-commutativeN/A

          \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(\color{blue}{\left(s \cdot u\right) \cdot \frac{3}{2}} + 3 \cdot s\right) \cdot u\right) \]
        8. associate-*l*N/A

          \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(\color{blue}{s \cdot \left(u \cdot \frac{3}{2}\right)} + 3 \cdot s\right) \cdot u\right) \]
        9. *-commutativeN/A

          \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(s \cdot \color{blue}{\left(\frac{3}{2} \cdot u\right)} + 3 \cdot s\right) \cdot u\right) \]
        10. *-commutativeN/A

          \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(s \cdot \left(\frac{3}{2} \cdot u\right) + \color{blue}{s \cdot 3}\right) \cdot u\right) \]
        11. distribute-lft-outN/A

          \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \color{blue}{\left(s \cdot \left(\frac{3}{2} \cdot u + 3\right)\right)} \cdot u\right) \]
        12. +-commutativeN/A

          \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(s \cdot \color{blue}{\left(3 + \frac{3}{2} \cdot u\right)}\right) \cdot u\right) \]
        13. lower-*.f32N/A

          \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \color{blue}{\left(s \cdot \left(3 + \frac{3}{2} \cdot u\right)\right)} \cdot u\right) \]
        14. +-commutativeN/A

          \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(s \cdot \color{blue}{\left(\frac{3}{2} \cdot u + 3\right)}\right) \cdot u\right) \]
        15. lower-fma.f327.1

          \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log 1.3333333333333333, \left(s \cdot \color{blue}{\mathsf{fma}\left(1.5, u, 3\right)}\right) \cdot u\right) \]
      7. Applied rewrites7.1%

        \[\leadsto \color{blue}{\mathsf{fma}\left(-3 \cdot s, \log 1.3333333333333333, \left(s \cdot \mathsf{fma}\left(1.5, u, 3\right)\right) \cdot u\right)} \]
      8. Taylor expanded in u around inf

        \[\leadsto \frac{3}{2} \cdot \color{blue}{\left(s \cdot {u}^{2}\right)} \]
      9. Step-by-step derivation
        1. Applied rewrites26.1%

          \[\leadsto \left(\left(u \cdot u\right) \cdot s\right) \cdot \color{blue}{1.5} \]
        2. Step-by-step derivation
          1. Applied rewrites26.1%

            \[\leadsto \left(1.5 \cdot u\right) \cdot \left(u \cdot \color{blue}{s}\right) \]
          2. Add Preprocessing

          Alternative 9: 26.4% accurate, 8.7× speedup?

          \[\begin{array}{l} \\ \left(\left(1.5 \cdot u\right) \cdot s\right) \cdot u \end{array} \]
          (FPCore (s u) :precision binary32 (* (* (* 1.5 u) s) u))
          float code(float s, float u) {
          	return ((1.5f * u) * s) * u;
          }
          
          real(4) function code(s, u)
              real(4), intent (in) :: s
              real(4), intent (in) :: u
              code = ((1.5e0 * u) * s) * u
          end function
          
          function code(s, u)
          	return Float32(Float32(Float32(Float32(1.5) * u) * s) * u)
          end
          
          function tmp = code(s, u)
          	tmp = ((single(1.5) * u) * s) * u;
          end
          
          \begin{array}{l}
          
          \\
          \left(\left(1.5 \cdot u\right) \cdot s\right) \cdot u
          \end{array}
          
          Derivation
          1. Initial program 96.1%

            \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
          2. Add Preprocessing
          3. Step-by-step derivation
            1. lift-*.f32N/A

              \[\leadsto \color{blue}{\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)} \]
            2. +-lft-identityN/A

              \[\leadsto \left(3 \cdot s\right) \cdot \color{blue}{\left(0 + \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)} \]
            3. metadata-evalN/A

              \[\leadsto \left(3 \cdot s\right) \cdot \left(\color{blue}{\log 1} + \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
            4. distribute-lft-inN/A

              \[\leadsto \color{blue}{\left(3 \cdot s\right) \cdot \log 1 + \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)} \]
            5. lift-*.f32N/A

              \[\leadsto \left(3 \cdot s\right) \cdot \log 1 + \color{blue}{\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)} \]
            6. lower-fma.f32N/A

              \[\leadsto \color{blue}{\mathsf{fma}\left(3 \cdot s, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)} \]
            7. lift-*.f32N/A

              \[\leadsto \mathsf{fma}\left(\color{blue}{3 \cdot s}, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
            8. *-commutativeN/A

              \[\leadsto \mathsf{fma}\left(\color{blue}{s \cdot 3}, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
            9. lower-*.f32N/A

              \[\leadsto \mathsf{fma}\left(\color{blue}{s \cdot 3}, \log 1, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
            10. metadata-eval7.4

              \[\leadsto \mathsf{fma}\left(s \cdot 3, \color{blue}{0}, \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right)\right) \]
            11. lift-*.f32N/A

              \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}\right) \]
            12. lift-*.f32N/A

              \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot s\right)} \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \]
            13. associate-*l*N/A

              \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{3 \cdot \left(s \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)}\right) \]
            14. *-commutativeN/A

              \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, 3 \cdot \color{blue}{\left(\log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right) \cdot s\right)}\right) \]
            15. associate-*r*N/A

              \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \cdot s}\right) \]
            16. lower-*.f32N/A

              \[\leadsto \mathsf{fma}\left(s \cdot 3, 0, \color{blue}{\left(3 \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right) \cdot s}\right) \]
          4. Applied rewrites33.1%

            \[\leadsto \color{blue}{\mathsf{fma}\left(s \cdot 3, 0, \left(-3 \cdot \mathsf{log1p}\left(-1.3333333333333333 \cdot \left(u - 0.25\right)\right)\right) \cdot s\right)} \]
          5. Taylor expanded in u around 0

            \[\leadsto \color{blue}{-3 \cdot \left(s \cdot \log \frac{4}{3}\right) + u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right)} \]
          6. Step-by-step derivation
            1. associate-*r*N/A

              \[\leadsto \color{blue}{\left(-3 \cdot s\right) \cdot \log \frac{4}{3}} + u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right) \]
            2. lower-fma.f32N/A

              \[\leadsto \color{blue}{\mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right)\right)} \]
            3. lower-*.f32N/A

              \[\leadsto \mathsf{fma}\left(\color{blue}{-3 \cdot s}, \log \frac{4}{3}, u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right)\right) \]
            4. lower-log.f32N/A

              \[\leadsto \mathsf{fma}\left(-3 \cdot s, \color{blue}{\log \frac{4}{3}}, u \cdot \left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right)\right) \]
            5. *-commutativeN/A

              \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \color{blue}{\left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right) \cdot u}\right) \]
            6. lower-*.f32N/A

              \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \color{blue}{\left(\frac{3}{2} \cdot \left(s \cdot u\right) + 3 \cdot s\right) \cdot u}\right) \]
            7. *-commutativeN/A

              \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(\color{blue}{\left(s \cdot u\right) \cdot \frac{3}{2}} + 3 \cdot s\right) \cdot u\right) \]
            8. associate-*l*N/A

              \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(\color{blue}{s \cdot \left(u \cdot \frac{3}{2}\right)} + 3 \cdot s\right) \cdot u\right) \]
            9. *-commutativeN/A

              \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(s \cdot \color{blue}{\left(\frac{3}{2} \cdot u\right)} + 3 \cdot s\right) \cdot u\right) \]
            10. *-commutativeN/A

              \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(s \cdot \left(\frac{3}{2} \cdot u\right) + \color{blue}{s \cdot 3}\right) \cdot u\right) \]
            11. distribute-lft-outN/A

              \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \color{blue}{\left(s \cdot \left(\frac{3}{2} \cdot u + 3\right)\right)} \cdot u\right) \]
            12. +-commutativeN/A

              \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(s \cdot \color{blue}{\left(3 + \frac{3}{2} \cdot u\right)}\right) \cdot u\right) \]
            13. lower-*.f32N/A

              \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \color{blue}{\left(s \cdot \left(3 + \frac{3}{2} \cdot u\right)\right)} \cdot u\right) \]
            14. +-commutativeN/A

              \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log \frac{4}{3}, \left(s \cdot \color{blue}{\left(\frac{3}{2} \cdot u + 3\right)}\right) \cdot u\right) \]
            15. lower-fma.f327.1

              \[\leadsto \mathsf{fma}\left(-3 \cdot s, \log 1.3333333333333333, \left(s \cdot \color{blue}{\mathsf{fma}\left(1.5, u, 3\right)}\right) \cdot u\right) \]
          7. Applied rewrites7.1%

            \[\leadsto \color{blue}{\mathsf{fma}\left(-3 \cdot s, \log 1.3333333333333333, \left(s \cdot \mathsf{fma}\left(1.5, u, 3\right)\right) \cdot u\right)} \]
          8. Taylor expanded in u around inf

            \[\leadsto \frac{3}{2} \cdot \color{blue}{\left(s \cdot {u}^{2}\right)} \]
          9. Step-by-step derivation
            1. Applied rewrites26.1%

              \[\leadsto \left(\left(u \cdot u\right) \cdot s\right) \cdot \color{blue}{1.5} \]
            2. Step-by-step derivation
              1. Applied rewrites26.1%

                \[\leadsto u \cdot \left(\left(1.5 \cdot u\right) \cdot \color{blue}{s}\right) \]
              2. Final simplification26.1%

                \[\leadsto \left(\left(1.5 \cdot u\right) \cdot s\right) \cdot u \]
              3. Add Preprocessing

              Reproduce

              ?
              herbie shell --seed 2024249 
              (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))))))