Disney BSSRDF, sample scattering profile, upper

Percentage Accurate: 95.9% → 96.7%
Time: 8.2s
Alternatives: 11
Speedup: 1.1×

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 11 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: 96.7% accurate, 1.1× speedup?

\[\begin{array}{l} \\ -\left(3 \cdot s\right) \cdot \log \left(1 - \frac{u - 0.25}{0.75}\right) \end{array} \]
(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}
Derivation
  1. Initial program 95.8%

    \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
  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-log.f32N/A

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

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

      \[\leadsto \log \color{blue}{\left({\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)} \cdot {\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)}\right)} \]
    5. pow-prod-downN/A

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \left(s \cdot \frac{3}{2}\right) \cdot \log \left({\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1} \cdot \color{blue}{{\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1}}\right) \]
  4. Applied rewrites96.4%

    \[\leadsto \color{blue}{\left(s \cdot 1.5\right) \cdot \log \left({\left(1 - \frac{u - 0.25}{0.75}\right)}^{-2}\right)} \]
  5. Step-by-step derivation
    1. lift-*.f32N/A

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

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

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

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto s \cdot \color{blue}{\left(3 \cdot \log \left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)\right)} \]
  6. Applied rewrites96.7%

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

Alternative 2: 25.8% accurate, 1.2× speedup?

\[\begin{array}{l} \\ \left(\left(\log 0.75 + u\right) \cdot s\right) \cdot 3 \end{array} \]
(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}
Derivation
  1. Initial program 95.8%

    \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
  2. Add Preprocessing
  3. Taylor expanded in u around 0

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

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

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

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

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

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

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

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

      \[\leadsto \left(\color{blue}{\left(\log \frac{3}{4} + u\right)} \cdot s\right) \cdot 3 \]
    9. lower-log.f3225.8

      \[\leadsto \left(\left(\color{blue}{\log 0.75} + u\right) \cdot s\right) \cdot 3 \]
  5. Applied rewrites25.8%

    \[\leadsto \color{blue}{\left(\left(\log 0.75 + u\right) \cdot s\right) \cdot 3} \]
  6. Add Preprocessing

Alternative 3: 7.3% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \left(3 \cdot s\right) \cdot \log 0.75 \end{array} \]
(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}
Derivation
  1. Initial program 95.8%

    \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
  2. Add Preprocessing
  3. Taylor expanded in u around 0

    \[\leadsto \left(3 \cdot s\right) \cdot \log \color{blue}{\frac{3}{4}} \]
  4. Step-by-step derivation
    1. Applied rewrites7.3%

      \[\leadsto \left(3 \cdot s\right) \cdot \log \color{blue}{0.75} \]
    2. Add Preprocessing

    Alternative 4: 7.3% accurate, 1.3× speedup?

    \[\begin{array}{l} \\ \left(\log 0.75 \cdot s\right) \cdot 3 \end{array} \]
    (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}
    
    Derivation
    1. Initial program 95.8%

      \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
    2. Add Preprocessing
    3. Taylor expanded in u around 0

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

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

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

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

        \[\leadsto \color{blue}{\left(\log \frac{3}{4} \cdot s\right)} \cdot 3 \]
      5. lower-log.f327.3

        \[\leadsto \left(\color{blue}{\log 0.75} \cdot s\right) \cdot 3 \]
    5. Applied rewrites7.3%

      \[\leadsto \color{blue}{\left(\log 0.75 \cdot s\right) \cdot 3} \]
    6. Add Preprocessing

    Alternative 5: 8.9% accurate, 3.6× speedup?

    \[\begin{array}{l} \\ \left(s \cdot 1.5\right) \cdot \mathsf{fma}\left(\frac{0}{0}, 2, \frac{0}{0}\right) \end{array} \]
    (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}
    
    Derivation
    1. Initial program 95.8%

      \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
    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-log.f32N/A

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

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

        \[\leadsto \log \color{blue}{\left({\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)} \cdot {\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)}\right)} \]
      5. pow-prod-downN/A

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(s \cdot \frac{3}{2}\right) \cdot \log \left({\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1} \cdot \color{blue}{{\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1}}\right) \]
    4. Applied rewrites96.4%

      \[\leadsto \color{blue}{\left(s \cdot 1.5\right) \cdot \log \left({\left(1 - \frac{u - 0.25}{0.75}\right)}^{-2}\right)} \]
    5. Applied rewrites-0.0%

      \[\leadsto \left(s \cdot 1.5\right) \cdot \color{blue}{\mathsf{fma}\left(\frac{0}{0}, 2, \frac{0}{0}\right)} \]
    6. Add Preprocessing

    Alternative 6: 10.8% accurate, 3.6× speedup?

    \[\begin{array}{l} \\ \left(s \cdot 1.5\right) \cdot \mathsf{fma}\left(3, \frac{0}{0}, \frac{0}{0}\right) \end{array} \]
    (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}
    
    Derivation
    1. Initial program 95.8%

      \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
    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-log.f32N/A

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

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

        \[\leadsto \log \color{blue}{\left({\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)} \cdot {\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)}\right)} \]
      5. pow-prod-downN/A

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(s \cdot \frac{3}{2}\right) \cdot \log \left({\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1} \cdot \color{blue}{{\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1}}\right) \]
    4. Applied rewrites96.4%

      \[\leadsto \color{blue}{\left(s \cdot 1.5\right) \cdot \log \left({\left(1 - \frac{u - 0.25}{0.75}\right)}^{-2}\right)} \]
    5. Applied rewrites-0.0%

      \[\leadsto \left(s \cdot 1.5\right) \cdot \color{blue}{\mathsf{fma}\left(3, \frac{0}{0}, \frac{0}{0}\right)} \]
    6. Add Preprocessing

    Alternative 7: 9.0% accurate, 3.6× speedup?

    \[\begin{array}{l} \\ \left(s \cdot 1.5\right) \cdot \mathsf{fma}\left(1.5, \frac{0}{0}, \frac{0}{0}\right) \end{array} \]
    (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}
    
    Derivation
    1. Initial program 95.8%

      \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
    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-log.f32N/A

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

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

        \[\leadsto \log \color{blue}{\left({\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)} \cdot {\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)}\right)} \]
      5. pow-prod-downN/A

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(s \cdot \frac{3}{2}\right) \cdot \log \left({\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1} \cdot \color{blue}{{\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1}}\right) \]
    4. Applied rewrites96.4%

      \[\leadsto \color{blue}{\left(s \cdot 1.5\right) \cdot \log \left({\left(1 - \frac{u - 0.25}{0.75}\right)}^{-2}\right)} \]
    5. Applied rewrites-0.0%

      \[\leadsto \left(s \cdot 1.5\right) \cdot \color{blue}{\mathsf{fma}\left(1.5, \frac{0}{0}, \frac{0}{0}\right)} \]
    6. Add Preprocessing

    Alternative 8: 2.8% accurate, 3.6× speedup?

    \[\begin{array}{l} \\ \left(s \cdot 1.5\right) \cdot \mathsf{fma}\left(0.5, \frac{0}{0}, \frac{0}{0}\right) \end{array} \]
    (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}
    
    Derivation
    1. Initial program 95.8%

      \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
    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-log.f32N/A

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

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

        \[\leadsto \log \color{blue}{\left({\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)} \cdot {\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)}\right)} \]
      5. pow-prod-downN/A

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(s \cdot \frac{3}{2}\right) \cdot \log \left({\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1} \cdot \color{blue}{{\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1}}\right) \]
    4. Applied rewrites96.4%

      \[\leadsto \color{blue}{\left(s \cdot 1.5\right) \cdot \log \left({\left(1 - \frac{u - 0.25}{0.75}\right)}^{-2}\right)} \]
    5. Applied rewrites-0.0%

      \[\leadsto \left(s \cdot 1.5\right) \cdot \color{blue}{\mathsf{fma}\left(0.5, \frac{0}{0}, \frac{0}{0}\right)} \]
    6. Add Preprocessing

    Alternative 9: 10.1% accurate, 5.0× speedup?

    \[\begin{array}{l} \\ \mathsf{fma}\left(s \cdot 2, \frac{0}{0}, \mathsf{NAN}\left(\right) \cdot s\right) \end{array} \]
    (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}
    
    Derivation
    1. Initial program 95.8%

      \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
    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-log.f32N/A

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

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

        \[\leadsto \log \color{blue}{\left({\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)} \cdot {\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)}\right)} \]
      5. pow-prod-downN/A

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(s \cdot \frac{3}{2}\right) \cdot \log \left({\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1} \cdot \color{blue}{{\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1}}\right) \]
    4. Applied rewrites96.4%

      \[\leadsto \color{blue}{\left(s \cdot 1.5\right) \cdot \log \left({\left(1 - \frac{u - 0.25}{0.75}\right)}^{-2}\right)} \]
    5. Applied rewrites-0.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(s \cdot 2, \frac{0}{0}, \frac{0}{0} \cdot s\right)} \]
    6. Taylor expanded in s around 0

      \[\leadsto \mathsf{fma}\left(s \cdot 2, \frac{0}{0}, \color{blue}{s \cdot \mathsf{NAN}\left(\right)}\right) \]
    7. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \mathsf{fma}\left(s \cdot 2, \frac{0}{0}, \color{blue}{\mathsf{NAN}\left(\right) \cdot s}\right) \]
      2. lower-*.f32N/A

        \[\leadsto \mathsf{fma}\left(s \cdot 2, \frac{0}{0}, \color{blue}{\mathsf{NAN}\left(\right) \cdot s}\right) \]
      3. lower-NAN.f32-0.0

        \[\leadsto \mathsf{fma}\left(s \cdot 2, \frac{0}{0}, \color{blue}{\mathsf{NAN}\left(\right)} \cdot s\right) \]
    8. Applied rewrites-0.0%

      \[\leadsto \mathsf{fma}\left(s \cdot 2, \frac{0}{0}, \color{blue}{\mathsf{NAN}\left(\right) \cdot s}\right) \]
    9. Add Preprocessing

    Alternative 10: 6.5% accurate, 5.0× speedup?

    \[\begin{array}{l} \\ \mathsf{fma}\left(\mathsf{NAN}\left(\right) \cdot s, 1.5, \frac{0}{0} \cdot s\right) \end{array} \]
    (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}
    
    Derivation
    1. Initial program 95.8%

      \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
    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-log.f32N/A

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

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

        \[\leadsto \log \color{blue}{\left({\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)} \cdot {\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)}\right)} \]
      5. pow-prod-downN/A

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(s \cdot \frac{3}{2}\right) \cdot \log \left({\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1} \cdot \color{blue}{{\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1}}\right) \]
    4. Applied rewrites96.4%

      \[\leadsto \color{blue}{\left(s \cdot 1.5\right) \cdot \log \left({\left(1 - \frac{u - 0.25}{0.75}\right)}^{-2}\right)} \]
    5. Applied rewrites0.0%

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{0}{0} \cdot s, 1.5, \frac{0}{0} \cdot s\right)} \]
    6. Taylor expanded in s around 0

      \[\leadsto \mathsf{fma}\left(\color{blue}{s \cdot \mathsf{NAN}\left(\right)}, \frac{3}{2}, \frac{0}{0} \cdot s\right) \]
    7. Step-by-step derivation
      1. *-commutativeN/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\mathsf{NAN}\left(\right) \cdot s}, \frac{3}{2}, \frac{0}{0} \cdot s\right) \]
      2. lower-*.f32N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{\mathsf{NAN}\left(\right) \cdot s}, \frac{3}{2}, \frac{0}{0} \cdot s\right) \]
      3. lower-NAN.f32-0.0

        \[\leadsto \mathsf{fma}\left(\color{blue}{\mathsf{NAN}\left(\right)} \cdot s, 1.5, \frac{0}{0} \cdot s\right) \]
    8. Applied rewrites-0.0%

      \[\leadsto \mathsf{fma}\left(\color{blue}{\mathsf{NAN}\left(\right) \cdot s}, 1.5, \frac{0}{0} \cdot s\right) \]
    9. Add Preprocessing

    Alternative 11: -0.0% accurate, 139.0× speedup?

    \[\begin{array}{l} \\ \mathsf{NAN}\left(\right) \end{array} \]
    (FPCore (s u) :precision binary32 (NAN))
    \begin{array}{l}
    
    \\
    \mathsf{NAN}\left(\right)
    \end{array}
    
    Derivation
    1. Initial program 95.8%

      \[\left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \]
    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-log.f32N/A

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

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

        \[\leadsto \log \color{blue}{\left({\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)} \cdot {\left(\frac{1}{1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}}\right)}^{\left(\frac{3 \cdot s}{2}\right)}\right)} \]
      5. pow-prod-downN/A

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(s \cdot \frac{3}{2}\right) \cdot \log \left({\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1} \cdot \color{blue}{{\left(1 - \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)}^{-1}}\right) \]
    4. Applied rewrites96.4%

      \[\leadsto \color{blue}{\left(s \cdot 1.5\right) \cdot \log \left({\left(1 - \frac{u - 0.25}{0.75}\right)}^{-2}\right)} \]
    5. Applied rewrites-0.0%

      \[\leadsto \color{blue}{\frac{s \cdot 0}{0}} \]
    6. Taylor expanded in s around 0

      \[\leadsto \color{blue}{\mathsf{NAN}\left(\right)} \]
    7. Step-by-step derivation
      1. lower-NAN.f32-0.0

        \[\leadsto \color{blue}{\mathsf{NAN}\left(\right)} \]
    8. Applied rewrites-0.0%

      \[\leadsto \color{blue}{\mathsf{NAN}\left(\right)} \]
    9. Add Preprocessing

    Reproduce

    ?
    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))))))