Disney BSSRDF, sample scattering profile, upper

Percentage Accurate: 95.8% → 98.4%

Time: 11.8s

Alternatives: 8

Speedup: 1.2×

Specification

\[\left(0 \leq s \land s \leq 256\right) \land \left(0.25 \leq u \land u \leq 1\right)\]

Math

\[\begin{array}{l} \\ \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \end{array} \]

FPCore

(FPCore (s u)
 :precision binary32
 (* (* 3.0 s) (log (/ 1.0 (- 1.0 (/ (- u 0.25) 0.75))))))

C

float code(float s, float u) {
	return (3.0f * s) * logf((1.0f / (1.0f - ((u - 0.25f) / 0.75f))));
}

Fortran

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

Julia

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

MATLAB

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

Initial Program: 95.8% accurate, 1.0× speedup

Math

\[\begin{array}{l} \\ \left(3 \cdot s\right) \cdot \log \left(\frac{1}{1 - \frac{u - 0.25}{0.75}}\right) \end{array} \]

FPCore

(FPCore (s u)
 :precision binary32
 (* (* 3.0 s) (log (/ 1.0 (- 1.0 (/ (- u 0.25) 0.75))))))

C

float code(float s, float u) {
	return (3.0f * s) * logf((1.0f / (1.0f - ((u - 0.25f) / 0.75f))));
}

Fortran

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

Julia

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

MATLAB

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

Alternative 1: 98.4% accurate, 0.6× speedup

Math

\[\begin{array}{l} \\ \mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) \cdot 3, s, s \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right) \cdot \left(0.25 - u\right)\right) \cdot \left(-3\right)\right)\right) \end{array} \]

FPCore

(FPCore (s u)
 :precision binary32
 (fma
  (* (log1p (fma u 1.3333333333333333 -0.3333333333333333)) 3.0)
  s
  (*
   s
   (*
    (log1p (* (fma u 1.7777777777777777 -0.4444444444444444) (- 0.25 u)))
    (- 3.0)))))

C

float code(float s, float u) {
	return fmaf((log1pf(fmaf(u, 1.3333333333333333f, -0.3333333333333333f)) * 3.0f), s, (s * (log1pf((fmaf(u, 1.7777777777777777f, -0.4444444444444444f) * (0.25f - u))) * -3.0f)));
}

Julia

function code(s, u)
	return fma(Float32(log1p(fma(u, Float32(1.3333333333333333), Float32(-0.3333333333333333))) * Float32(3.0)), s, Float32(s * Float32(log1p(Float32(fma(u, Float32(1.7777777777777777), Float32(-0.4444444444444444)) * Float32(Float32(0.25) - u))) * Float32(-Float32(3.0)))))
end

Derivation

1. Initial program 95.9%

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

   1. lift-log.f32 N/A

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

   2. lift-/.f32 N/A

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

   3. lift--.f32 N/A

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

   4. flip-- N/A

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

   5. clear-num N/A

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

   6. log-div N/A

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

   7. lower--.f32 N/A

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

   8. lower-log1p.f32 N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\color{blue}{\mathsf{log1p}\left(\frac{u - \frac{1}{4}}{\frac{3}{4}}\right)} - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   9. lift-/.f32 N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u - \frac{1}{4}}{\frac{3}{4}}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   10. lift--.f32 N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\frac{\color{blue}{u - \frac{1}{4}}}{\frac{3}{4}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   11. div-sub N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u}{\frac{3}{4}} - \frac{\frac{1}{4}}{\frac{3}{4}}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   12. sub-neg N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u}{\frac{3}{4}} + \left(\mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   13. div-inv N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{u \cdot \frac{1}{\frac{3}{4}}} + \left(\mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   14. lower-fma.f32 N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(u, \frac{1}{\frac{3}{4}}, \mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   15. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \color{blue}{\frac{4}{3}}, \mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   16. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \mathsf{neg}\left(\color{blue}{\frac{1}{3}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   17. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \color{blue}{\frac{-1}{3}}\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

4. Applied rewrites 98.2%

   \[\leadsto \left(3 \cdot s\right) \cdot \color{blue}{\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) - \mathsf{log1p}\left(\left(0.25 - u\right) \cdot \left(1.7777777777777777 \cdot \left(u + -0.25\right)\right)\right)\right)} \]

6. Applied rewrites 98.3%

   \[\leadsto \color{blue}{\mathsf{fma}\left(3 \cdot s, \mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right), \left(3 \cdot s\right) \cdot \left(-\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right) \cdot \left(0.25 - u\right)\right)\right)\right)} \]

8. Applied rewrites 98.4%

   \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) \cdot 3, s, -s \cdot \left(3 \cdot \mathsf{log1p}\left(\mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right) \cdot \left(0.25 - u\right)\right)\right)\right)} \]

9. Final simplification 98.4%

   \[\leadsto \mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) \cdot 3, s, s \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right) \cdot \left(0.25 - u\right)\right) \cdot \left(-3\right)\right)\right) \]
10. Add Preprocessing

Alternative 2: 98.3% accurate, 0.6× speedup

Math

\[\begin{array}{l} \\ \mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) \cdot 3, s, s \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \mathsf{fma}\left(u, -1.7777777777777777, 0.8888888888888888\right), -0.1111111111111111\right)\right) \cdot \left(-3\right)\right)\right) \end{array} \]

FPCore

(FPCore (s u)
 :precision binary32
 (fma
  (* (log1p (fma u 1.3333333333333333 -0.3333333333333333)) 3.0)
  s
  (*
   s
   (*
    (log1p
     (fma
      u
      (fma u -1.7777777777777777 0.8888888888888888)
      -0.1111111111111111))
    (- 3.0)))))

C

float code(float s, float u) {
	return fmaf((log1pf(fmaf(u, 1.3333333333333333f, -0.3333333333333333f)) * 3.0f), s, (s * (log1pf(fmaf(u, fmaf(u, -1.7777777777777777f, 0.8888888888888888f), -0.1111111111111111f)) * -3.0f)));
}

Julia

function code(s, u)
	return fma(Float32(log1p(fma(u, Float32(1.3333333333333333), Float32(-0.3333333333333333))) * Float32(3.0)), s, Float32(s * Float32(log1p(fma(u, fma(u, Float32(-1.7777777777777777), Float32(0.8888888888888888)), Float32(-0.1111111111111111))) * Float32(-Float32(3.0)))))
end

Derivation

1. Initial program 95.9%

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

   1. lift-log.f32 N/A

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

   2. lift-/.f32 N/A

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

   3. lift--.f32 N/A

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

   4. flip-- N/A

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

   5. clear-num N/A

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

   6. log-div N/A

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

   7. lower--.f32 N/A

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

   8. lower-log1p.f32 N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\color{blue}{\mathsf{log1p}\left(\frac{u - \frac{1}{4}}{\frac{3}{4}}\right)} - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   9. lift-/.f32 N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u - \frac{1}{4}}{\frac{3}{4}}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   10. lift--.f32 N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\frac{\color{blue}{u - \frac{1}{4}}}{\frac{3}{4}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   11. div-sub N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u}{\frac{3}{4}} - \frac{\frac{1}{4}}{\frac{3}{4}}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   12. sub-neg N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u}{\frac{3}{4}} + \left(\mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   13. div-inv N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{u \cdot \frac{1}{\frac{3}{4}}} + \left(\mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   14. lower-fma.f32 N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(u, \frac{1}{\frac{3}{4}}, \mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   15. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \color{blue}{\frac{4}{3}}, \mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   16. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \mathsf{neg}\left(\color{blue}{\frac{1}{3}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   17. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \color{blue}{\frac{-1}{3}}\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

4. Applied rewrites 98.2%

   \[\leadsto \left(3 \cdot s\right) \cdot \color{blue}{\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) - \mathsf{log1p}\left(\left(0.25 - u\right) \cdot \left(1.7777777777777777 \cdot \left(u + -0.25\right)\right)\right)\right)} \]

6. Applied rewrites 98.3%

   \[\leadsto \color{blue}{\mathsf{fma}\left(3 \cdot s, \mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right), \left(3 \cdot s\right) \cdot \left(-\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right) \cdot \left(0.25 - u\right)\right)\right)\right)} \]

8. Applied rewrites 98.4%

   \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) \cdot 3, s, -s \cdot \left(3 \cdot \mathsf{log1p}\left(\mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right) \cdot \left(0.25 - u\right)\right)\right)\right)} \]

9. Taylor expanded in u around 0

   \[\leadsto \mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) \cdot 3, s, \mathsf{neg}\left(s \cdot \left(3 \cdot \mathsf{log1p}\left(\color{blue}{u \cdot \left(\frac{8}{9} + \frac{-16}{9} \cdot u\right) - \frac{1}{9}}\right)\right)\right)\right) \]
10. Step-by-step derivation

    1. sub-neg N/A

       \[\leadsto \mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) \cdot 3, s, \mathsf{neg}\left(s \cdot \left(3 \cdot \mathsf{log1p}\left(\color{blue}{u \cdot \left(\frac{8}{9} + \frac{-16}{9} \cdot u\right) + \left(\mathsf{neg}\left(\frac{1}{9}\right)\right)}\right)\right)\right)\right) \]

    2. lower-fma.f32 N/A

       \[\leadsto \mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) \cdot 3, s, \mathsf{neg}\left(s \cdot \left(3 \cdot \mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(u, \frac{8}{9} + \frac{-16}{9} \cdot u, \mathsf{neg}\left(\frac{1}{9}\right)\right)}\right)\right)\right)\right) \]

    3. +-commutative N/A

       \[\leadsto \mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) \cdot 3, s, \mathsf{neg}\left(s \cdot \left(3 \cdot \mathsf{log1p}\left(\mathsf{fma}\left(u, \color{blue}{\frac{-16}{9} \cdot u + \frac{8}{9}}, \mathsf{neg}\left(\frac{1}{9}\right)\right)\right)\right)\right)\right) \]

    4. *-commutative N/A

       \[\leadsto \mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) \cdot 3, s, \mathsf{neg}\left(s \cdot \left(3 \cdot \mathsf{log1p}\left(\mathsf{fma}\left(u, \color{blue}{u \cdot \frac{-16}{9}} + \frac{8}{9}, \mathsf{neg}\left(\frac{1}{9}\right)\right)\right)\right)\right)\right) \]

    5. lower-fma.f32 N/A

       \[\leadsto \mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) \cdot 3, s, \mathsf{neg}\left(s \cdot \left(3 \cdot \mathsf{log1p}\left(\mathsf{fma}\left(u, \color{blue}{\mathsf{fma}\left(u, \frac{-16}{9}, \frac{8}{9}\right)}, \mathsf{neg}\left(\frac{1}{9}\right)\right)\right)\right)\right)\right) \]

    6. metadata-eval 98.3

       \[\leadsto \mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) \cdot 3, s, -s \cdot \left(3 \cdot \mathsf{log1p}\left(\mathsf{fma}\left(u, \mathsf{fma}\left(u, -1.7777777777777777, 0.8888888888888888\right), \color{blue}{-0.1111111111111111}\right)\right)\right)\right) \]

11. Applied rewrites 98.3%

    \[\leadsto \mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) \cdot 3, s, -s \cdot \left(3 \cdot \mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(u, \mathsf{fma}\left(u, -1.7777777777777777, 0.8888888888888888\right), -0.1111111111111111\right)}\right)\right)\right) \]

12. Final simplification 98.3%

    \[\leadsto \mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) \cdot 3, s, s \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \mathsf{fma}\left(u, -1.7777777777777777, 0.8888888888888888\right), -0.1111111111111111\right)\right) \cdot \left(-3\right)\right)\right) \]
13. Add Preprocessing

Alternative 3: 98.3% accurate, 0.6× speedup

Math

\[\begin{array}{l} \\ s \cdot \mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right) \cdot \left(0.25 - u\right)\right), -3, \mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) \cdot 3\right) \end{array} \]

FPCore

(FPCore (s u)
 :precision binary32
 (*
  s
  (fma
   (log1p (* (fma u 1.7777777777777777 -0.4444444444444444) (- 0.25 u)))
   -3.0
   (* (log1p (fma u 1.3333333333333333 -0.3333333333333333)) 3.0))))

C

float code(float s, float u) {
	return s * fmaf(log1pf((fmaf(u, 1.7777777777777777f, -0.4444444444444444f) * (0.25f - u))), -3.0f, (log1pf(fmaf(u, 1.3333333333333333f, -0.3333333333333333f)) * 3.0f));
}

Julia

function code(s, u)
	return Float32(s * fma(log1p(Float32(fma(u, Float32(1.7777777777777777), Float32(-0.4444444444444444)) * Float32(Float32(0.25) - u))), Float32(-3.0), Float32(log1p(fma(u, Float32(1.3333333333333333), Float32(-0.3333333333333333))) * Float32(3.0))))
end

Derivation

1. Initial program 95.9%

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

   1. lift-log.f32 N/A

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

   2. lift-/.f32 N/A

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

   3. lift--.f32 N/A

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

   4. flip-- N/A

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

   5. clear-num N/A

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

   6. log-div N/A

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

   7. lower--.f32 N/A

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

   8. lower-log1p.f32 N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\color{blue}{\mathsf{log1p}\left(\frac{u - \frac{1}{4}}{\frac{3}{4}}\right)} - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   9. lift-/.f32 N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u - \frac{1}{4}}{\frac{3}{4}}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   10. lift--.f32 N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\frac{\color{blue}{u - \frac{1}{4}}}{\frac{3}{4}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   11. div-sub N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u}{\frac{3}{4}} - \frac{\frac{1}{4}}{\frac{3}{4}}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   12. sub-neg N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u}{\frac{3}{4}} + \left(\mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   13. div-inv N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{u \cdot \frac{1}{\frac{3}{4}}} + \left(\mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   14. lower-fma.f32 N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(u, \frac{1}{\frac{3}{4}}, \mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   15. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \color{blue}{\frac{4}{3}}, \mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   16. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \mathsf{neg}\left(\color{blue}{\frac{1}{3}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   17. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \color{blue}{\frac{-1}{3}}\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

4. Applied rewrites 98.2%

   \[\leadsto \left(3 \cdot s\right) \cdot \color{blue}{\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) - \mathsf{log1p}\left(\left(0.25 - u\right) \cdot \left(1.7777777777777777 \cdot \left(u + -0.25\right)\right)\right)\right)} \]

6. Applied rewrites 98.3%

   \[\leadsto \color{blue}{\mathsf{fma}\left(3 \cdot s, \mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right), \left(3 \cdot s\right) \cdot \left(-\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right) \cdot \left(0.25 - u\right)\right)\right)\right)} \]

7. Taylor expanded in s around 0

   \[\leadsto \color{blue}{s \cdot \left(-3 \cdot \log \left(1 + \left(\frac{1}{4} - u\right) \cdot \left(\frac{16}{9} \cdot u - \frac{4}{9}\right)\right) + 3 \cdot \log \left(\frac{2}{3} + \frac{4}{3} \cdot u\right)\right)} \]
8. Step-by-step derivation

   1. lower-*.f32 N/A

      \[\leadsto \color{blue}{s \cdot \left(-3 \cdot \log \left(1 + \left(\frac{1}{4} - u\right) \cdot \left(\frac{16}{9} \cdot u - \frac{4}{9}\right)\right) + 3 \cdot \log \left(\frac{2}{3} + \frac{4}{3} \cdot u\right)\right)} \]

   2. lower-fma.f32 N/A

      \[\leadsto s \cdot \color{blue}{\mathsf{fma}\left(-3, \log \left(1 + \left(\frac{1}{4} - u\right) \cdot \left(\frac{16}{9} \cdot u - \frac{4}{9}\right)\right), 3 \cdot \log \left(\frac{2}{3} + \frac{4}{3} \cdot u\right)\right)} \]

   3. lower-log1p.f32 N/A

      \[\leadsto s \cdot \mathsf{fma}\left(-3, \color{blue}{\mathsf{log1p}\left(\left(\frac{1}{4} - u\right) \cdot \left(\frac{16}{9} \cdot u - \frac{4}{9}\right)\right)}, 3 \cdot \log \left(\frac{2}{3} + \frac{4}{3} \cdot u\right)\right) \]

   4. lower-*.f32 N/A

      \[\leadsto s \cdot \mathsf{fma}\left(-3, \mathsf{log1p}\left(\color{blue}{\left(\frac{1}{4} - u\right) \cdot \left(\frac{16}{9} \cdot u - \frac{4}{9}\right)}\right), 3 \cdot \log \left(\frac{2}{3} + \frac{4}{3} \cdot u\right)\right) \]

   5. lower--.f32 N/A

      \[\leadsto s \cdot \mathsf{fma}\left(-3, \mathsf{log1p}\left(\color{blue}{\left(\frac{1}{4} - u\right)} \cdot \left(\frac{16}{9} \cdot u - \frac{4}{9}\right)\right), 3 \cdot \log \left(\frac{2}{3} + \frac{4}{3} \cdot u\right)\right) \]

   6. sub-neg N/A

      \[\leadsto s \cdot \mathsf{fma}\left(-3, \mathsf{log1p}\left(\left(\frac{1}{4} - u\right) \cdot \color{blue}{\left(\frac{16}{9} \cdot u + \left(\mathsf{neg}\left(\frac{4}{9}\right)\right)\right)}\right), 3 \cdot \log \left(\frac{2}{3} + \frac{4}{3} \cdot u\right)\right) \]

   7. *-commutative N/A

      \[\leadsto s \cdot \mathsf{fma}\left(-3, \mathsf{log1p}\left(\left(\frac{1}{4} - u\right) \cdot \left(\color{blue}{u \cdot \frac{16}{9}} + \left(\mathsf{neg}\left(\frac{4}{9}\right)\right)\right)\right), 3 \cdot \log \left(\frac{2}{3} + \frac{4}{3} \cdot u\right)\right) \]

   8. metadata-eval N/A

      \[\leadsto s \cdot \mathsf{fma}\left(-3, \mathsf{log1p}\left(\left(\frac{1}{4} - u\right) \cdot \left(u \cdot \frac{16}{9} + \color{blue}{\frac{-4}{9}}\right)\right), 3 \cdot \log \left(\frac{2}{3} + \frac{4}{3} \cdot u\right)\right) \]

   9. lower-fma.f32 N/A

      \[\leadsto s \cdot \mathsf{fma}\left(-3, \mathsf{log1p}\left(\left(\frac{1}{4} - u\right) \cdot \color{blue}{\mathsf{fma}\left(u, \frac{16}{9}, \frac{-4}{9}\right)}\right), 3 \cdot \log \left(\frac{2}{3} + \frac{4}{3} \cdot u\right)\right) \]

   10. lower-*.f32 N/A

       \[\leadsto s \cdot \mathsf{fma}\left(-3, \mathsf{log1p}\left(\left(\frac{1}{4} - u\right) \cdot \mathsf{fma}\left(u, \frac{16}{9}, \frac{-4}{9}\right)\right), \color{blue}{3 \cdot \log \left(\frac{2}{3} + \frac{4}{3} \cdot u\right)}\right) \]

   11. lower-log.f32 N/A

       \[\leadsto s \cdot \mathsf{fma}\left(-3, \mathsf{log1p}\left(\left(\frac{1}{4} - u\right) \cdot \mathsf{fma}\left(u, \frac{16}{9}, \frac{-4}{9}\right)\right), 3 \cdot \color{blue}{\log \left(\frac{2}{3} + \frac{4}{3} \cdot u\right)}\right) \]

   12. +-commutative N/A

       \[\leadsto s \cdot \mathsf{fma}\left(-3, \mathsf{log1p}\left(\left(\frac{1}{4} - u\right) \cdot \mathsf{fma}\left(u, \frac{16}{9}, \frac{-4}{9}\right)\right), 3 \cdot \log \color{blue}{\left(\frac{4}{3} \cdot u + \frac{2}{3}\right)}\right) \]

   13. *-commutative N/A

       \[\leadsto s \cdot \mathsf{fma}\left(-3, \mathsf{log1p}\left(\left(\frac{1}{4} - u\right) \cdot \mathsf{fma}\left(u, \frac{16}{9}, \frac{-4}{9}\right)\right), 3 \cdot \log \left(\color{blue}{u \cdot \frac{4}{3}} + \frac{2}{3}\right)\right) \]

   14. lower-fma.f32 96.2

       \[\leadsto s \cdot \mathsf{fma}\left(-3, \mathsf{log1p}\left(\left(0.25 - u\right) \cdot \mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right)\right), 3 \cdot \log \color{blue}{\left(\mathsf{fma}\left(u, 1.3333333333333333, 0.6666666666666666\right)\right)}\right) \]

9. Applied rewrites 96.2%

   \[\leadsto \color{blue}{s \cdot \mathsf{fma}\left(-3, \mathsf{log1p}\left(\left(0.25 - u\right) \cdot \mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right)\right), 3 \cdot \log \left(\mathsf{fma}\left(u, 1.3333333333333333, 0.6666666666666666\right)\right)\right)} \]
10. Step-by-step derivation

11. Applied rewrites 98.3%

    \[\leadsto s \cdot \mathsf{fma}\left(\mathsf{log1p}\left(\left(0.25 - u\right) \cdot \mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right)\right), \color{blue}{-3}, \mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) \cdot 3\right) \]

12. Final simplification 98.3%

    \[\leadsto s \cdot \mathsf{fma}\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right) \cdot \left(0.25 - u\right)\right), -3, \mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) \cdot 3\right) \]
13. Add Preprocessing

Alternative 4: 98.2% accurate, 0.6× speedup

Math

\[\begin{array}{l} \\ \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right) \cdot \left(0.25 - u\right)\right)\right) \end{array} \]

FPCore

(FPCore (s u)
 :precision binary32
 (*
  (* 3.0 s)
  (-
   (log1p (fma u 1.3333333333333333 -0.3333333333333333))
   (log1p (* (fma u 1.7777777777777777 -0.4444444444444444) (- 0.25 u))))))

C

float code(float s, float u) {
	return (3.0f * s) * (log1pf(fmaf(u, 1.3333333333333333f, -0.3333333333333333f)) - log1pf((fmaf(u, 1.7777777777777777f, -0.4444444444444444f) * (0.25f - u))));
}

Julia

function code(s, u)
	return Float32(Float32(Float32(3.0) * s) * Float32(log1p(fma(u, Float32(1.3333333333333333), Float32(-0.3333333333333333))) - log1p(Float32(fma(u, Float32(1.7777777777777777), Float32(-0.4444444444444444)) * Float32(Float32(0.25) - u)))))
end

Derivation

1. Initial program 95.9%

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

   1. lift-log.f32 N/A

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

   2. lift-/.f32 N/A

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

   3. lift--.f32 N/A

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

   4. flip-- N/A

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

   5. clear-num N/A

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

   6. log-div N/A

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

   7. lower--.f32 N/A

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

   8. lower-log1p.f32 N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\color{blue}{\mathsf{log1p}\left(\frac{u - \frac{1}{4}}{\frac{3}{4}}\right)} - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   9. lift-/.f32 N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u - \frac{1}{4}}{\frac{3}{4}}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   10. lift--.f32 N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\frac{\color{blue}{u - \frac{1}{4}}}{\frac{3}{4}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   11. div-sub N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u}{\frac{3}{4}} - \frac{\frac{1}{4}}{\frac{3}{4}}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   12. sub-neg N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u}{\frac{3}{4}} + \left(\mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   13. div-inv N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{u \cdot \frac{1}{\frac{3}{4}}} + \left(\mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   14. lower-fma.f32 N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(u, \frac{1}{\frac{3}{4}}, \mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   15. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \color{blue}{\frac{4}{3}}, \mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   16. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \mathsf{neg}\left(\color{blue}{\frac{1}{3}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   17. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \color{blue}{\frac{-1}{3}}\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

4. Applied rewrites 98.2%

   \[\leadsto \left(3 \cdot s\right) \cdot \color{blue}{\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) - \mathsf{log1p}\left(\left(0.25 - u\right) \cdot \left(1.7777777777777777 \cdot \left(u + -0.25\right)\right)\right)\right)} \]
5. Step-by-step derivation

   1. lift-*.f32 N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\color{blue}{\left(\frac{1}{4} - u\right) \cdot \left(\frac{16}{9} \cdot \left(u + \frac{-1}{4}\right)\right)}\right)\right) \]

   2. *-commutative N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\color{blue}{\left(\frac{16}{9} \cdot \left(u + \frac{-1}{4}\right)\right) \cdot \left(\frac{1}{4} - u\right)}\right)\right) \]

   3. lift--.f32 N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\left(\frac{16}{9} \cdot \left(u + \frac{-1}{4}\right)\right) \cdot \color{blue}{\left(\frac{1}{4} - u\right)}\right)\right) \]

   4. sub-neg N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\left(\frac{16}{9} \cdot \left(u + \frac{-1}{4}\right)\right) \cdot \color{blue}{\left(\frac{1}{4} + \left(\mathsf{neg}\left(u\right)\right)\right)}\right)\right) \]

   5. metadata-eval N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\left(\frac{16}{9} \cdot \left(u + \frac{-1}{4}\right)\right) \cdot \left(\color{blue}{\left(\mathsf{neg}\left(\frac{-1}{4}\right)\right)} + \left(\mathsf{neg}\left(u\right)\right)\right)\right)\right) \]

   6. distribute-neg-in N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\left(\frac{16}{9} \cdot \left(u + \frac{-1}{4}\right)\right) \cdot \color{blue}{\left(\mathsf{neg}\left(\left(\frac{-1}{4} + u\right)\right)\right)}\right)\right) \]

   7. +-commutative N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\left(\frac{16}{9} \cdot \left(u + \frac{-1}{4}\right)\right) \cdot \left(\mathsf{neg}\left(\color{blue}{\left(u + \frac{-1}{4}\right)}\right)\right)\right)\right) \]

   8. metadata-eval N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\left(\frac{16}{9} \cdot \left(u + \frac{-1}{4}\right)\right) \cdot \left(\mathsf{neg}\left(\left(u + \color{blue}{\left(\mathsf{neg}\left(\frac{1}{4}\right)\right)}\right)\right)\right)\right)\right) \]

   9. sub-neg N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\left(\frac{16}{9} \cdot \left(u + \frac{-1}{4}\right)\right) \cdot \left(\mathsf{neg}\left(\color{blue}{\left(u - \frac{1}{4}\right)}\right)\right)\right)\right) \]

   10. lower-*.f32 N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\color{blue}{\left(\frac{16}{9} \cdot \left(u + \frac{-1}{4}\right)\right) \cdot \left(\mathsf{neg}\left(\left(u - \frac{1}{4}\right)\right)\right)}\right)\right) \]

   11. lift-*.f32 N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\color{blue}{\left(\frac{16}{9} \cdot \left(u + \frac{-1}{4}\right)\right)} \cdot \left(\mathsf{neg}\left(\left(u - \frac{1}{4}\right)\right)\right)\right)\right) \]

   12. lift-+.f32 N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\left(\frac{16}{9} \cdot \color{blue}{\left(u + \frac{-1}{4}\right)}\right) \cdot \left(\mathsf{neg}\left(\left(u - \frac{1}{4}\right)\right)\right)\right)\right) \]

   13. distribute-lft-in N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\color{blue}{\left(\frac{16}{9} \cdot u + \frac{16}{9} \cdot \frac{-1}{4}\right)} \cdot \left(\mathsf{neg}\left(\left(u - \frac{1}{4}\right)\right)\right)\right)\right) \]

   14. *-commutative N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\left(\color{blue}{u \cdot \frac{16}{9}} + \frac{16}{9} \cdot \frac{-1}{4}\right) \cdot \left(\mathsf{neg}\left(\left(u - \frac{1}{4}\right)\right)\right)\right)\right) \]

   15. lower-fma.f32 N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(u, \frac{16}{9}, \frac{16}{9} \cdot \frac{-1}{4}\right)} \cdot \left(\mathsf{neg}\left(\left(u - \frac{1}{4}\right)\right)\right)\right)\right) \]

   16. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{16}{9}, \color{blue}{\frac{-4}{9}}\right) \cdot \left(\mathsf{neg}\left(\left(u - \frac{1}{4}\right)\right)\right)\right)\right) \]

   17. sub-neg N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{16}{9}, \frac{-4}{9}\right) \cdot \left(\mathsf{neg}\left(\color{blue}{\left(u + \left(\mathsf{neg}\left(\frac{1}{4}\right)\right)\right)}\right)\right)\right)\right) \]

   18. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{16}{9}, \frac{-4}{9}\right) \cdot \left(\mathsf{neg}\left(\left(u + \color{blue}{\frac{-1}{4}}\right)\right)\right)\right)\right) \]

   19. +-commutative N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{16}{9}, \frac{-4}{9}\right) \cdot \left(\mathsf{neg}\left(\color{blue}{\left(\frac{-1}{4} + u\right)}\right)\right)\right)\right) \]

   20. distribute-neg-in N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{16}{9}, \frac{-4}{9}\right) \cdot \color{blue}{\left(\left(\mathsf{neg}\left(\frac{-1}{4}\right)\right) + \left(\mathsf{neg}\left(u\right)\right)\right)}\right)\right) \]

   21. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{16}{9}, \frac{-4}{9}\right) \cdot \left(\color{blue}{\frac{1}{4}} + \left(\mathsf{neg}\left(u\right)\right)\right)\right)\right) \]

   22. sub-neg N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{16}{9}, \frac{-4}{9}\right) \cdot \color{blue}{\left(\frac{1}{4} - u\right)}\right)\right) \]

   23. lift--.f32 98.2

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right) \cdot \color{blue}{\left(0.25 - u\right)}\right)\right) \]

6. Applied rewrites 98.2%

   \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) - \mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(u, 1.7777777777777777, -0.4444444444444444\right) \cdot \left(0.25 - u\right)}\right)\right) \]
7. Add Preprocessing

Alternative 5: 98.1% accurate, 0.6× speedup

Math

\[\begin{array}{l} \\ \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, \mathsf{fma}\left(u, -1.7777777777777777, 0.8888888888888888\right), -0.1111111111111111\right)\right)\right) \end{array} \]

FPCore

(FPCore (s u)
 :precision binary32
 (*
  (* 3.0 s)
  (-
   (log1p (fma u 1.3333333333333333 -0.3333333333333333))
   (log1p
    (fma
     u
     (fma u -1.7777777777777777 0.8888888888888888)
     -0.1111111111111111)))))

C

float code(float s, float u) {
	return (3.0f * s) * (log1pf(fmaf(u, 1.3333333333333333f, -0.3333333333333333f)) - log1pf(fmaf(u, fmaf(u, -1.7777777777777777f, 0.8888888888888888f), -0.1111111111111111f)));
}

Julia

function code(s, u)
	return Float32(Float32(Float32(3.0) * s) * Float32(log1p(fma(u, Float32(1.3333333333333333), Float32(-0.3333333333333333))) - log1p(fma(u, fma(u, Float32(-1.7777777777777777), Float32(0.8888888888888888)), Float32(-0.1111111111111111)))))
end

Derivation

1. Initial program 95.9%

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

   1. lift-log.f32 N/A

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

   2. lift-/.f32 N/A

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

   3. lift--.f32 N/A

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

   4. flip-- N/A

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

   5. clear-num N/A

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

   6. log-div N/A

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

   7. lower--.f32 N/A

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

   8. lower-log1p.f32 N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\color{blue}{\mathsf{log1p}\left(\frac{u - \frac{1}{4}}{\frac{3}{4}}\right)} - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   9. lift-/.f32 N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u - \frac{1}{4}}{\frac{3}{4}}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   10. lift--.f32 N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\frac{\color{blue}{u - \frac{1}{4}}}{\frac{3}{4}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   11. div-sub N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u}{\frac{3}{4}} - \frac{\frac{1}{4}}{\frac{3}{4}}}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   12. sub-neg N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\frac{u}{\frac{3}{4}} + \left(\mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   13. div-inv N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{u \cdot \frac{1}{\frac{3}{4}}} + \left(\mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   14. lower-fma.f32 N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(u, \frac{1}{\frac{3}{4}}, \mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)}\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   15. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \color{blue}{\frac{4}{3}}, \mathsf{neg}\left(\frac{\frac{1}{4}}{\frac{3}{4}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   16. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \mathsf{neg}\left(\color{blue}{\frac{1}{3}}\right)\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

   17. metadata-eval N/A

       \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \color{blue}{\frac{-1}{3}}\right)\right) - \log \left(1 \cdot 1 - \frac{u - \frac{1}{4}}{\frac{3}{4}} \cdot \frac{u - \frac{1}{4}}{\frac{3}{4}}\right)\right) \]

4. Applied rewrites 98.2%

   \[\leadsto \left(3 \cdot s\right) \cdot \color{blue}{\left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) - \mathsf{log1p}\left(\left(0.25 - u\right) \cdot \left(1.7777777777777777 \cdot \left(u + -0.25\right)\right)\right)\right)} \]

5. Taylor expanded in u around 0

   \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\color{blue}{u \cdot \left(\frac{8}{9} + \frac{-16}{9} \cdot u\right) - \frac{1}{9}}\right)\right) \]
6. Step-by-step derivation

   1. sub-neg N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\color{blue}{u \cdot \left(\frac{8}{9} + \frac{-16}{9} \cdot u\right) + \left(\mathsf{neg}\left(\frac{1}{9}\right)\right)}\right)\right) \]

   2. lower-fma.f32 N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(u, \frac{8}{9} + \frac{-16}{9} \cdot u, \mathsf{neg}\left(\frac{1}{9}\right)\right)}\right)\right) \]

   3. +-commutative N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, \color{blue}{\frac{-16}{9} \cdot u + \frac{8}{9}}, \mathsf{neg}\left(\frac{1}{9}\right)\right)\right)\right) \]

   4. *-commutative N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, \color{blue}{u \cdot \frac{-16}{9}} + \frac{8}{9}, \mathsf{neg}\left(\frac{1}{9}\right)\right)\right)\right) \]

   5. lower-fma.f32 N/A

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, \frac{4}{3}, \frac{-1}{3}\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, \color{blue}{\mathsf{fma}\left(u, \frac{-16}{9}, \frac{8}{9}\right)}, \mathsf{neg}\left(\frac{1}{9}\right)\right)\right)\right) \]

   6. metadata-eval 98.1

      \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) - \mathsf{log1p}\left(\mathsf{fma}\left(u, \mathsf{fma}\left(u, -1.7777777777777777, 0.8888888888888888\right), \color{blue}{-0.1111111111111111}\right)\right)\right) \]

7. Applied rewrites 98.1%

   \[\leadsto \left(3 \cdot s\right) \cdot \left(\mathsf{log1p}\left(\mathsf{fma}\left(u, 1.3333333333333333, -0.3333333333333333\right)\right) - \mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(u, \mathsf{fma}\left(u, -1.7777777777777777, 0.8888888888888888\right), -0.1111111111111111\right)}\right)\right) \]
8. Add Preprocessing

Alternative 6: 97.9% accurate, 1.2× speedup

Math

\[\begin{array}{l} \\ \left(s \cdot -3\right) \cdot \mathsf{log1p}\left(\mathsf{fma}\left(-1.3333333333333333, u, 0.3333333333333333\right)\right) \end{array} \]

FPCore

(FPCore (s u)
 :precision binary32
 (* (* s -3.0) (log1p (fma -1.3333333333333333 u 0.3333333333333333))))

C

float code(float s, float u) {
	return (s * -3.0f) * log1pf(fmaf(-1.3333333333333333f, u, 0.3333333333333333f));
}

Julia

function code(s, u)
	return Float32(Float32(s * Float32(-3.0)) * log1p(fma(Float32(-1.3333333333333333), u, Float32(0.3333333333333333))))
end

Derivation

1. Initial program 95.9%

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

3. Taylor expanded in s around 0

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

   1. associate-*r* N/A

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

   2. log-rec N/A

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

   3. distribute-rgt-neg-out N/A

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

   4. distribute-lft-neg-in N/A

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

   5. distribute-lft-neg-in N/A

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

   6. metadata-eval N/A

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

   7. lower-*.f32 N/A

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

   8. *-commutative N/A

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

   9. lower-*.f32 N/A

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

   10. sub-neg N/A

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

   11. lower-log1p.f32 N/A

       \[\leadsto \left(s \cdot -3\right) \cdot \color{blue}{\mathsf{log1p}\left(\mathsf{neg}\left(\frac{4}{3} \cdot \left(u - \frac{1}{4}\right)\right)\right)} \]

   12. distribute-lft-neg-in N/A

       \[\leadsto \left(s \cdot -3\right) \cdot \mathsf{log1p}\left(\color{blue}{\left(\mathsf{neg}\left(\frac{4}{3}\right)\right) \cdot \left(u - \frac{1}{4}\right)}\right) \]

   13. metadata-eval N/A

       \[\leadsto \left(s \cdot -3\right) \cdot \mathsf{log1p}\left(\color{blue}{\frac{-4}{3}} \cdot \left(u - \frac{1}{4}\right)\right) \]

   14. sub-neg N/A

       \[\leadsto \left(s \cdot -3\right) \cdot \mathsf{log1p}\left(\frac{-4}{3} \cdot \color{blue}{\left(u + \left(\mathsf{neg}\left(\frac{1}{4}\right)\right)\right)}\right) \]

   15. distribute-lft-in N/A

       \[\leadsto \left(s \cdot -3\right) \cdot \mathsf{log1p}\left(\color{blue}{\frac{-4}{3} \cdot u + \frac{-4}{3} \cdot \left(\mathsf{neg}\left(\frac{1}{4}\right)\right)}\right) \]

   16. metadata-eval N/A

       \[\leadsto \left(s \cdot -3\right) \cdot \mathsf{log1p}\left(\frac{-4}{3} \cdot u + \frac{-4}{3} \cdot \color{blue}{\frac{-1}{4}}\right) \]

   17. metadata-eval N/A

       \[\leadsto \left(s \cdot -3\right) \cdot \mathsf{log1p}\left(\frac{-4}{3} \cdot u + \color{blue}{\frac{1}{3}}\right) \]

   18. lower-fma.f32 97.8

       \[\leadsto \left(s \cdot -3\right) \cdot \mathsf{log1p}\left(\color{blue}{\mathsf{fma}\left(-1.3333333333333333, u, 0.3333333333333333\right)}\right) \]

5. Applied rewrites 97.8%

   \[\leadsto \color{blue}{\left(s \cdot -3\right) \cdot \mathsf{log1p}\left(\mathsf{fma}\left(-1.3333333333333333, u, 0.3333333333333333\right)\right)} \]
6. Add Preprocessing

Alternative 7: 29.9% accurate, 12.6× speedup

Math

\[\begin{array}{l} \\ s \cdot \left(u \cdot 3\right) \end{array} \]

FPCore

(FPCore (s u) :precision binary32 (* s (* u 3.0)))

C

float code(float s, float u) {
	return s * (u * 3.0f);
}

Fortran

real(4) function code(s, u)
    real(4), intent (in) :: s
    real(4), intent (in) :: u
    code = s * (u * 3.0e0)
end function

Julia

function code(s, u)
	return Float32(s * Float32(u * Float32(3.0)))
end

MATLAB

function tmp = code(s, u)
	tmp = s * (u * single(3.0));
end

Derivation

1. Initial program 95.9%

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

5. Applied rewrites 7.1%

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

6. Taylor expanded in u around 0

   \[\leadsto \color{blue}{3 \cdot \left(s \cdot u\right) + 3 \cdot \left(s \cdot \log \frac{3}{4}\right)} \]
7. Step-by-step derivation

   1. associate-*r* N/A

      \[\leadsto \color{blue}{\left(3 \cdot s\right) \cdot u} + 3 \cdot \left(s \cdot \log \frac{3}{4}\right) \]

   2. associate-*r* N/A

      \[\leadsto \left(3 \cdot s\right) \cdot u + \color{blue}{\left(3 \cdot s\right) \cdot \log \frac{3}{4}} \]

   3. distribute-lft-out N/A

      \[\leadsto \color{blue}{\left(3 \cdot s\right) \cdot \left(u + \log \frac{3}{4}\right)} \]

   4. *-commutative N/A

      \[\leadsto \color{blue}{\left(s \cdot 3\right)} \cdot \left(u + \log \frac{3}{4}\right) \]

   5. associate-*l* N/A

      \[\leadsto \color{blue}{s \cdot \left(3 \cdot \left(u + \log \frac{3}{4}\right)\right)} \]

   6. lower-*.f32 N/A

      \[\leadsto \color{blue}{s \cdot \left(3 \cdot \left(u + \log \frac{3}{4}\right)\right)} \]

   7. lower-*.f32 N/A

      \[\leadsto s \cdot \color{blue}{\left(3 \cdot \left(u + \log \frac{3}{4}\right)\right)} \]

   8. lower-+.f32 N/A

      \[\leadsto s \cdot \left(3 \cdot \color{blue}{\left(u + \log \frac{3}{4}\right)}\right) \]

   9. lower-log.f32 25.4

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

8. Applied rewrites 25.4%

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

9. Taylor expanded in u around inf

   \[\leadsto s \cdot \left(3 \cdot \color{blue}{u}\right) \]
10. Step-by-step derivation

11. Applied rewrites 29.6%

    \[\leadsto s \cdot \left(3 \cdot \color{blue}{u}\right) \]

12. Final simplification 29.6%

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

Alternative 8: 29.9% accurate, 12.6× speedup

Math

\[\begin{array}{l} \\ 3 \cdot \left(u \cdot s\right) \end{array} \]

FPCore

(FPCore (s u) :precision binary32 (* 3.0 (* u s)))

C

float code(float s, float u) {
	return 3.0f * (u * s);
}

Fortran

real(4) function code(s, u)
    real(4), intent (in) :: s
    real(4), intent (in) :: u
    code = 3.0e0 * (u * s)
end function

Julia

function code(s, u)
	return Float32(Float32(3.0) * Float32(u * s))
end

MATLAB

function tmp = code(s, u)
	tmp = single(3.0) * (u * s);
end

Derivation

1. Initial program 95.9%

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

5. Applied rewrites 7.1%

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

6. Taylor expanded in u around 0

   \[\leadsto \color{blue}{3 \cdot \left(s \cdot u\right) + 3 \cdot \left(s \cdot \log \frac{3}{4}\right)} \]
7. Step-by-step derivation

   1. associate-*r* N/A

      \[\leadsto \color{blue}{\left(3 \cdot s\right) \cdot u} + 3 \cdot \left(s \cdot \log \frac{3}{4}\right) \]

   2. associate-*r* N/A

      \[\leadsto \left(3 \cdot s\right) \cdot u + \color{blue}{\left(3 \cdot s\right) \cdot \log \frac{3}{4}} \]

   3. distribute-lft-out N/A

      \[\leadsto \color{blue}{\left(3 \cdot s\right) \cdot \left(u + \log \frac{3}{4}\right)} \]

   4. *-commutative N/A

      \[\leadsto \color{blue}{\left(s \cdot 3\right)} \cdot \left(u + \log \frac{3}{4}\right) \]

   5. associate-*l* N/A

      \[\leadsto \color{blue}{s \cdot \left(3 \cdot \left(u + \log \frac{3}{4}\right)\right)} \]

   6. lower-*.f32 N/A

      \[\leadsto \color{blue}{s \cdot \left(3 \cdot \left(u + \log \frac{3}{4}\right)\right)} \]

   7. lower-*.f32 N/A

      \[\leadsto s \cdot \color{blue}{\left(3 \cdot \left(u + \log \frac{3}{4}\right)\right)} \]

   8. lower-+.f32 N/A

      \[\leadsto s \cdot \left(3 \cdot \color{blue}{\left(u + \log \frac{3}{4}\right)}\right) \]

   9. lower-log.f32 25.4

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

8. Applied rewrites 25.4%

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

9. Taylor expanded in u around inf

   \[\leadsto 3 \cdot \color{blue}{\left(s \cdot u\right)} \]
10. Step-by-step derivation

11. Applied rewrites 29.6%

    \[\leadsto 3 \cdot \color{blue}{\left(s \cdot u\right)} \]

12. Final simplification 29.6%

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

Reproduce

herbie shell --seed 2024234 
(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))))))