Sample trimmed logistic on [-pi, pi]

Percentage Accurate: 98.9% → 98.9%
Time: 15.3s
Alternatives: 10
Speedup: 1.3×

Specification

?
\[\left(2.328306437 \cdot 10^{-10} \leq u \land u \leq 1\right) \land \left(0 \leq s \land s \leq 1.0651631\right)\]
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{1 + e^{\frac{\pi}{s}}}\\ \left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - t\_0\right) + t\_0} - 1\right) \end{array} \end{array} \]
(FPCore (u s)
 :precision binary32
 (let* ((t_0 (/ 1.0 (+ 1.0 (exp (/ PI s))))))
   (*
    (- s)
    (log
     (-
      (/ 1.0 (+ (* u (- (/ 1.0 (+ 1.0 (exp (/ (- PI) s)))) t_0)) t_0))
      1.0)))))
float code(float u, float s) {
	float t_0 = 1.0f / (1.0f + expf((((float) M_PI) / s)));
	return -s * logf(((1.0f / ((u * ((1.0f / (1.0f + expf((-((float) M_PI) / s)))) - t_0)) + t_0)) - 1.0f));
}
function code(u, s)
	t_0 = Float32(Float32(1.0) / Float32(Float32(1.0) + exp(Float32(Float32(pi) / s))))
	return Float32(Float32(-s) * log(Float32(Float32(Float32(1.0) / Float32(Float32(u * Float32(Float32(Float32(1.0) / Float32(Float32(1.0) + exp(Float32(Float32(-Float32(pi)) / s)))) - t_0)) + t_0)) - Float32(1.0))))
end
function tmp = code(u, s)
	t_0 = single(1.0) / (single(1.0) + exp((single(pi) / s)));
	tmp = -s * log(((single(1.0) / ((u * ((single(1.0) / (single(1.0) + exp((-single(pi) / s)))) - t_0)) + t_0)) - single(1.0)));
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1}{1 + e^{\frac{\pi}{s}}}\\
\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - t\_0\right) + t\_0} - 1\right)
\end{array}
\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 10 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: 98.9% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{1}{1 + e^{\frac{\pi}{s}}}\\ \left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - t\_0\right) + t\_0} - 1\right) \end{array} \end{array} \]
(FPCore (u s)
 :precision binary32
 (let* ((t_0 (/ 1.0 (+ 1.0 (exp (/ PI s))))))
   (*
    (- s)
    (log
     (-
      (/ 1.0 (+ (* u (- (/ 1.0 (+ 1.0 (exp (/ (- PI) s)))) t_0)) t_0))
      1.0)))))
float code(float u, float s) {
	float t_0 = 1.0f / (1.0f + expf((((float) M_PI) / s)));
	return -s * logf(((1.0f / ((u * ((1.0f / (1.0f + expf((-((float) M_PI) / s)))) - t_0)) + t_0)) - 1.0f));
}
function code(u, s)
	t_0 = Float32(Float32(1.0) / Float32(Float32(1.0) + exp(Float32(Float32(pi) / s))))
	return Float32(Float32(-s) * log(Float32(Float32(Float32(1.0) / Float32(Float32(u * Float32(Float32(Float32(1.0) / Float32(Float32(1.0) + exp(Float32(Float32(-Float32(pi)) / s)))) - t_0)) + t_0)) - Float32(1.0))))
end
function tmp = code(u, s)
	t_0 = single(1.0) / (single(1.0) + exp((single(pi) / s)));
	tmp = -s * log(((single(1.0) / ((u * ((single(1.0) / (single(1.0) + exp((-single(pi) / s)))) - t_0)) + t_0)) - single(1.0)));
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{1}{1 + e^{\frac{\pi}{s}}}\\
\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - t\_0\right) + t\_0} - 1\right)
\end{array}
\end{array}

Alternative 1: 98.9% accurate, 1.3× speedup?

\[\begin{array}{l} \\ s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right) \end{array} \]
(FPCore (u s)
 :precision binary32
 (*
  s
  (-
   (log
    (+
     (/
      1.0
      (+
       (/ u (+ 1.0 (exp (/ PI (- s)))))
       (/ (- 1.0 u) (+ 1.0 (exp (/ PI s))))))
     -1.0)))))
float code(float u, float s) {
	return s * -logf(((1.0f / ((u / (1.0f + expf((((float) M_PI) / -s)))) + ((1.0f - u) / (1.0f + expf((((float) M_PI) / s)))))) + -1.0f));
}
function code(u, s)
	return Float32(s * Float32(-log(Float32(Float32(Float32(1.0) / Float32(Float32(u / Float32(Float32(1.0) + exp(Float32(Float32(pi) / Float32(-s))))) + Float32(Float32(Float32(1.0) - u) / Float32(Float32(1.0) + exp(Float32(Float32(pi) / s)))))) + Float32(-1.0)))))
end
function tmp = code(u, s)
	tmp = s * -log(((single(1.0) / ((u / (single(1.0) + exp((single(pi) / -s)))) + ((single(1.0) - u) / (single(1.0) + exp((single(pi) / s)))))) + single(-1.0)));
end
\begin{array}{l}

\\
s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right)
\end{array}
Derivation
  1. Initial program 98.9%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.9%

    \[\leadsto \color{blue}{s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right)} \]
  3. Add Preprocessing
  4. Final simplification98.9%

    \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right) \]
  5. Add Preprocessing

Alternative 2: 37.6% accurate, 2.0× speedup?

\[\begin{array}{l} \\ s \cdot \left(-\log \left(-1 + \frac{1}{\frac{u}{2} + \frac{1 - u}{1 + {e}^{\left(\frac{\pi}{s}\right)}}}\right)\right) \end{array} \]
(FPCore (u s)
 :precision binary32
 (*
  s
  (-
   (log
    (+ -1.0 (/ 1.0 (+ (/ u 2.0) (/ (- 1.0 u) (+ 1.0 (pow E (/ PI s)))))))))))
float code(float u, float s) {
	return s * -logf((-1.0f + (1.0f / ((u / 2.0f) + ((1.0f - u) / (1.0f + powf(((float) M_E), (((float) M_PI) / s))))))));
}
function code(u, s)
	return Float32(s * Float32(-log(Float32(Float32(-1.0) + Float32(Float32(1.0) / Float32(Float32(u / Float32(2.0)) + Float32(Float32(Float32(1.0) - u) / Float32(Float32(1.0) + (Float32(exp(1)) ^ Float32(Float32(pi) / s))))))))))
end
function tmp = code(u, s)
	tmp = s * -log((single(-1.0) + (single(1.0) / ((u / single(2.0)) + ((single(1.0) - u) / (single(1.0) + (single(2.71828182845904523536) ^ (single(pi) / s))))))));
end
\begin{array}{l}

\\
s \cdot \left(-\log \left(-1 + \frac{1}{\frac{u}{2} + \frac{1 - u}{1 + {e}^{\left(\frac{\pi}{s}\right)}}}\right)\right)
\end{array}
Derivation
  1. Initial program 98.9%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.9%

    \[\leadsto \color{blue}{s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around inf 37.8%

    \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + \color{blue}{1}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right) \]
  5. Step-by-step derivation
    1. *-un-lft-identity37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + e^{\color{blue}{1 \cdot \frac{\pi}{s}}}}} + -1\right)\right) \]
    2. exp-prod37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + \color{blue}{{\left(e^{1}\right)}^{\left(\frac{\pi}{s}\right)}}}} + -1\right)\right) \]
  6. Applied egg-rr37.8%

    \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + \color{blue}{{\left(e^{1}\right)}^{\left(\frac{\pi}{s}\right)}}}} + -1\right)\right) \]
  7. Step-by-step derivation
    1. exp-1-e37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + {\color{blue}{e}}^{\left(\frac{\pi}{s}\right)}}} + -1\right)\right) \]
  8. Simplified37.8%

    \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + \color{blue}{{e}^{\left(\frac{\pi}{s}\right)}}}} + -1\right)\right) \]
  9. Final simplification37.8%

    \[\leadsto s \cdot \left(-\log \left(-1 + \frac{1}{\frac{u}{2} + \frac{1 - u}{1 + {e}^{\left(\frac{\pi}{s}\right)}}}\right)\right) \]
  10. Add Preprocessing

Alternative 3: 37.6% accurate, 2.0× speedup?

\[\begin{array}{l} \\ s \cdot \left(-\log \left(-1 + \frac{1}{\frac{1 - u}{1 + e^{\frac{\pi}{s}}} + u \cdot 0.5}\right)\right) \end{array} \]
(FPCore (u s)
 :precision binary32
 (*
  s
  (-
   (log (+ -1.0 (/ 1.0 (+ (/ (- 1.0 u) (+ 1.0 (exp (/ PI s)))) (* u 0.5))))))))
float code(float u, float s) {
	return s * -logf((-1.0f + (1.0f / (((1.0f - u) / (1.0f + expf((((float) M_PI) / s)))) + (u * 0.5f)))));
}
function code(u, s)
	return Float32(s * Float32(-log(Float32(Float32(-1.0) + Float32(Float32(1.0) / Float32(Float32(Float32(Float32(1.0) - u) / Float32(Float32(1.0) + exp(Float32(Float32(pi) / s)))) + Float32(u * Float32(0.5))))))))
end
function tmp = code(u, s)
	tmp = s * -log((single(-1.0) + (single(1.0) / (((single(1.0) - u) / (single(1.0) + exp((single(pi) / s)))) + (u * single(0.5))))));
end
\begin{array}{l}

\\
s \cdot \left(-\log \left(-1 + \frac{1}{\frac{1 - u}{1 + e^{\frac{\pi}{s}}} + u \cdot 0.5}\right)\right)
\end{array}
Derivation
  1. Initial program 98.9%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.9%

    \[\leadsto \color{blue}{s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around inf 37.8%

    \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + \color{blue}{1}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right) \]
  5. Step-by-step derivation
    1. *-un-lft-identity37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + e^{\color{blue}{1 \cdot \frac{\pi}{s}}}}} + -1\right)\right) \]
    2. exp-prod37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + \color{blue}{{\left(e^{1}\right)}^{\left(\frac{\pi}{s}\right)}}}} + -1\right)\right) \]
  6. Applied egg-rr37.8%

    \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + \color{blue}{{\left(e^{1}\right)}^{\left(\frac{\pi}{s}\right)}}}} + -1\right)\right) \]
  7. Step-by-step derivation
    1. exp-1-e37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + {\color{blue}{e}}^{\left(\frac{\pi}{s}\right)}}} + -1\right)\right) \]
  8. Simplified37.8%

    \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + \color{blue}{{e}^{\left(\frac{\pi}{s}\right)}}}} + -1\right)\right) \]
  9. Step-by-step derivation
    1. e-exp-137.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + {\color{blue}{\left(e^{1}\right)}}^{\left(\frac{\pi}{s}\right)}}} + -1\right)\right) \]
    2. add-sqr-sqrt37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + {\left(e^{1}\right)}^{\color{blue}{\left(\sqrt{\frac{\pi}{s}} \cdot \sqrt{\frac{\pi}{s}}\right)}}}} + -1\right)\right) \]
    3. sqrt-unprod37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + {\left(e^{1}\right)}^{\color{blue}{\left(\sqrt{\frac{\pi}{s} \cdot \frac{\pi}{s}}\right)}}}} + -1\right)\right) \]
    4. sqr-neg37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + {\left(e^{1}\right)}^{\left(\sqrt{\color{blue}{\left(-\frac{\pi}{s}\right) \cdot \left(-\frac{\pi}{s}\right)}}\right)}}} + -1\right)\right) \]
    5. sqrt-unprod-0.0%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + {\left(e^{1}\right)}^{\color{blue}{\left(\sqrt{-\frac{\pi}{s}} \cdot \sqrt{-\frac{\pi}{s}}\right)}}}} + -1\right)\right) \]
    6. add-sqr-sqrt6.4%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + {\left(e^{1}\right)}^{\color{blue}{\left(-\frac{\pi}{s}\right)}}}} + -1\right)\right) \]
    7. exp-prod6.4%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + \color{blue}{e^{1 \cdot \left(-\frac{\pi}{s}\right)}}}} + -1\right)\right) \]
    8. *-un-lft-identity6.4%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + e^{\color{blue}{-\frac{\pi}{s}}}}} + -1\right)\right) \]
    9. exp-neg6.4%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + \color{blue}{\frac{1}{e^{\frac{\pi}{s}}}}}} + -1\right)\right) \]
  10. Applied egg-rr6.4%

    \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + \color{blue}{\frac{1}{e^{\frac{\pi}{s}}}}}} + -1\right)\right) \]
  11. Step-by-step derivation
    1. rec-exp6.4%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + \color{blue}{e^{-\frac{\pi}{s}}}}} + -1\right)\right) \]
    2. distribute-neg-frac6.4%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + e^{\color{blue}{\frac{-\pi}{s}}}}} + -1\right)\right) \]
  12. Simplified6.4%

    \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + \color{blue}{e^{\frac{-\pi}{s}}}}} + -1\right)\right) \]
  13. Step-by-step derivation
    1. +-commutative6.4%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\color{blue}{\frac{1 - u}{1 + e^{\frac{-\pi}{s}}} + \frac{u}{1 + 1}}} + -1\right)\right) \]
    2. *-un-lft-identity6.4%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\color{blue}{1 \cdot \frac{1 - u}{1 + e^{\frac{-\pi}{s}}}} + \frac{u}{1 + 1}} + -1\right)\right) \]
    3. fma-def6.4%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\color{blue}{\mathsf{fma}\left(1, \frac{1 - u}{1 + e^{\frac{-\pi}{s}}}, \frac{u}{1 + 1}\right)}} + -1\right)\right) \]
    4. clear-num6.4%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\mathsf{fma}\left(1, \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{\frac{s}{-\pi}}}}}, \frac{u}{1 + 1}\right)} + -1\right)\right) \]
    5. clear-num6.4%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\mathsf{fma}\left(1, \frac{1 - u}{1 + e^{\color{blue}{\frac{-\pi}{s}}}}, \frac{u}{1 + 1}\right)} + -1\right)\right) \]
    6. add-sqr-sqrt-0.0%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\mathsf{fma}\left(1, \frac{1 - u}{1 + e^{\frac{\color{blue}{\sqrt{-\pi} \cdot \sqrt{-\pi}}}{s}}}, \frac{u}{1 + 1}\right)} + -1\right)\right) \]
    7. sqrt-unprod37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\mathsf{fma}\left(1, \frac{1 - u}{1 + e^{\frac{\color{blue}{\sqrt{\left(-\pi\right) \cdot \left(-\pi\right)}}}{s}}}, \frac{u}{1 + 1}\right)} + -1\right)\right) \]
    8. sqr-neg37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\mathsf{fma}\left(1, \frac{1 - u}{1 + e^{\frac{\sqrt{\color{blue}{\pi \cdot \pi}}}{s}}}, \frac{u}{1 + 1}\right)} + -1\right)\right) \]
    9. sqrt-unprod37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\mathsf{fma}\left(1, \frac{1 - u}{1 + e^{\frac{\color{blue}{\sqrt{\pi} \cdot \sqrt{\pi}}}{s}}}, \frac{u}{1 + 1}\right)} + -1\right)\right) \]
    10. add-sqr-sqrt37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\mathsf{fma}\left(1, \frac{1 - u}{1 + e^{\frac{\color{blue}{\pi}}{s}}}, \frac{u}{1 + 1}\right)} + -1\right)\right) \]
    11. div-inv37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\mathsf{fma}\left(1, \frac{1 - u}{1 + e^{\frac{\pi}{s}}}, \color{blue}{u \cdot \frac{1}{1 + 1}}\right)} + -1\right)\right) \]
    12. metadata-eval37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\mathsf{fma}\left(1, \frac{1 - u}{1 + e^{\frac{\pi}{s}}}, u \cdot \frac{1}{\color{blue}{2}}\right)} + -1\right)\right) \]
    13. metadata-eval37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\mathsf{fma}\left(1, \frac{1 - u}{1 + e^{\frac{\pi}{s}}}, u \cdot \color{blue}{0.5}\right)} + -1\right)\right) \]
  14. Applied egg-rr37.8%

    \[\leadsto s \cdot \left(-\log \left(\frac{1}{\color{blue}{\mathsf{fma}\left(1, \frac{1 - u}{1 + e^{\frac{\pi}{s}}}, u \cdot 0.5\right)}} + -1\right)\right) \]
  15. Step-by-step derivation
    1. fma-udef37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\color{blue}{1 \cdot \frac{1 - u}{1 + e^{\frac{\pi}{s}}} + u \cdot 0.5}} + -1\right)\right) \]
    2. *-lft-identity37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\color{blue}{\frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + u \cdot 0.5} + -1\right)\right) \]
    3. *-commutative37.8%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{1 - u}{1 + e^{\frac{\pi}{s}}} + \color{blue}{0.5 \cdot u}} + -1\right)\right) \]
  16. Simplified37.8%

    \[\leadsto s \cdot \left(-\log \left(\frac{1}{\color{blue}{\frac{1 - u}{1 + e^{\frac{\pi}{s}}} + 0.5 \cdot u}} + -1\right)\right) \]
  17. Final simplification37.8%

    \[\leadsto s \cdot \left(-\log \left(-1 + \frac{1}{\frac{1 - u}{1 + e^{\frac{\pi}{s}}} + u \cdot 0.5}\right)\right) \]
  18. Add Preprocessing

Alternative 4: 36.2% accurate, 3.5× speedup?

\[\begin{array}{l} \\ s \cdot \left(-\log \left(-1 + \frac{1}{\frac{u}{2} + \frac{1 - u}{1 + \left(1 + \frac{\pi}{s}\right)}}\right)\right) \end{array} \]
(FPCore (u s)
 :precision binary32
 (*
  s
  (-
   (log
    (+ -1.0 (/ 1.0 (+ (/ u 2.0) (/ (- 1.0 u) (+ 1.0 (+ 1.0 (/ PI s)))))))))))
float code(float u, float s) {
	return s * -logf((-1.0f + (1.0f / ((u / 2.0f) + ((1.0f - u) / (1.0f + (1.0f + (((float) M_PI) / s))))))));
}
function code(u, s)
	return Float32(s * Float32(-log(Float32(Float32(-1.0) + Float32(Float32(1.0) / Float32(Float32(u / Float32(2.0)) + Float32(Float32(Float32(1.0) - u) / Float32(Float32(1.0) + Float32(Float32(1.0) + Float32(Float32(pi) / s))))))))))
end
function tmp = code(u, s)
	tmp = s * -log((single(-1.0) + (single(1.0) / ((u / single(2.0)) + ((single(1.0) - u) / (single(1.0) + (single(1.0) + (single(pi) / s))))))));
end
\begin{array}{l}

\\
s \cdot \left(-\log \left(-1 + \frac{1}{\frac{u}{2} + \frac{1 - u}{1 + \left(1 + \frac{\pi}{s}\right)}}\right)\right)
\end{array}
Derivation
  1. Initial program 98.9%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.9%

    \[\leadsto \color{blue}{s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around inf 37.8%

    \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + \color{blue}{1}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right) \]
  5. Taylor expanded in s around inf 35.9%

    \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + 1} + \frac{1 - u}{1 + \color{blue}{\left(1 + \frac{\pi}{s}\right)}}} + -1\right)\right) \]
  6. Final simplification35.9%

    \[\leadsto s \cdot \left(-\log \left(-1 + \frac{1}{\frac{u}{2} + \frac{1 - u}{1 + \left(1 + \frac{\pi}{s}\right)}}\right)\right) \]
  7. Add Preprocessing

Alternative 5: 11.7% accurate, 3.9× speedup?

\[\begin{array}{l} \\ 4 \cdot \left(\pi \cdot \left(u \cdot 0.25 - \mathsf{fma}\left(u, -0.25, 0.25\right)\right)\right) \end{array} \]
(FPCore (u s)
 :precision binary32
 (* 4.0 (* PI (- (* u 0.25) (fma u -0.25 0.25)))))
float code(float u, float s) {
	return 4.0f * (((float) M_PI) * ((u * 0.25f) - fmaf(u, -0.25f, 0.25f)));
}
function code(u, s)
	return Float32(Float32(4.0) * Float32(Float32(pi) * Float32(Float32(u * Float32(0.25)) - fma(u, Float32(-0.25), Float32(0.25)))))
end
\begin{array}{l}

\\
4 \cdot \left(\pi \cdot \left(u \cdot 0.25 - \mathsf{fma}\left(u, -0.25, 0.25\right)\right)\right)
\end{array}
Derivation
  1. Initial program 98.9%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.9%

    \[\leadsto \color{blue}{s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around inf 12.0%

    \[\leadsto \color{blue}{4 \cdot \left(0.25 \cdot \left(u \cdot \pi\right) - \left(-0.25 \cdot \left(u \cdot \pi\right) + 0.25 \cdot \pi\right)\right)} \]
  5. Step-by-step derivation
    1. sub-neg12.0%

      \[\leadsto 4 \cdot \color{blue}{\left(0.25 \cdot \left(u \cdot \pi\right) + \left(-\left(-0.25 \cdot \left(u \cdot \pi\right) + 0.25 \cdot \pi\right)\right)\right)} \]
    2. associate-*r*12.0%

      \[\leadsto 4 \cdot \left(0.25 \cdot \left(u \cdot \pi\right) + \left(-\left(\color{blue}{\left(-0.25 \cdot u\right) \cdot \pi} + 0.25 \cdot \pi\right)\right)\right) \]
    3. *-commutative12.0%

      \[\leadsto 4 \cdot \left(0.25 \cdot \left(u \cdot \pi\right) + \left(-\left(\color{blue}{\left(u \cdot -0.25\right)} \cdot \pi + 0.25 \cdot \pi\right)\right)\right) \]
    4. distribute-rgt-in12.0%

      \[\leadsto 4 \cdot \left(0.25 \cdot \left(u \cdot \pi\right) + \left(-\color{blue}{\pi \cdot \left(u \cdot -0.25 + 0.25\right)}\right)\right) \]
    5. fma-def12.0%

      \[\leadsto 4 \cdot \left(0.25 \cdot \left(u \cdot \pi\right) + \left(-\pi \cdot \color{blue}{\mathsf{fma}\left(u, -0.25, 0.25\right)}\right)\right) \]
  6. Applied egg-rr12.0%

    \[\leadsto 4 \cdot \color{blue}{\left(0.25 \cdot \left(u \cdot \pi\right) + \left(-\pi \cdot \mathsf{fma}\left(u, -0.25, 0.25\right)\right)\right)} \]
  7. Step-by-step derivation
    1. sub-neg12.0%

      \[\leadsto 4 \cdot \color{blue}{\left(0.25 \cdot \left(u \cdot \pi\right) - \pi \cdot \mathsf{fma}\left(u, -0.25, 0.25\right)\right)} \]
    2. *-commutative12.0%

      \[\leadsto 4 \cdot \left(0.25 \cdot \left(u \cdot \pi\right) - \color{blue}{\mathsf{fma}\left(u, -0.25, 0.25\right) \cdot \pi}\right) \]
    3. associate-*r*12.0%

      \[\leadsto 4 \cdot \left(\color{blue}{\left(0.25 \cdot u\right) \cdot \pi} - \mathsf{fma}\left(u, -0.25, 0.25\right) \cdot \pi\right) \]
    4. distribute-rgt-out--12.0%

      \[\leadsto 4 \cdot \color{blue}{\left(\pi \cdot \left(0.25 \cdot u - \mathsf{fma}\left(u, -0.25, 0.25\right)\right)\right)} \]
    5. *-commutative12.0%

      \[\leadsto 4 \cdot \left(\pi \cdot \left(\color{blue}{u \cdot 0.25} - \mathsf{fma}\left(u, -0.25, 0.25\right)\right)\right) \]
  8. Simplified12.0%

    \[\leadsto 4 \cdot \color{blue}{\left(\pi \cdot \left(u \cdot 0.25 - \mathsf{fma}\left(u, -0.25, 0.25\right)\right)\right)} \]
  9. Final simplification12.0%

    \[\leadsto 4 \cdot \left(\pi \cdot \left(u \cdot 0.25 - \mathsf{fma}\left(u, -0.25, 0.25\right)\right)\right) \]
  10. Add Preprocessing

Alternative 6: 11.7% accurate, 28.9× speedup?

\[\begin{array}{l} \\ -4 \cdot \left(\pi \cdot \left(0.25 + u \cdot -0.25\right) + u \cdot \left(\pi \cdot -0.25\right)\right) \end{array} \]
(FPCore (u s)
 :precision binary32
 (* -4.0 (+ (* PI (+ 0.25 (* u -0.25))) (* u (* PI -0.25)))))
float code(float u, float s) {
	return -4.0f * ((((float) M_PI) * (0.25f + (u * -0.25f))) + (u * (((float) M_PI) * -0.25f)));
}
function code(u, s)
	return Float32(Float32(-4.0) * Float32(Float32(Float32(pi) * Float32(Float32(0.25) + Float32(u * Float32(-0.25)))) + Float32(u * Float32(Float32(pi) * Float32(-0.25)))))
end
function tmp = code(u, s)
	tmp = single(-4.0) * ((single(pi) * (single(0.25) + (u * single(-0.25)))) + (u * (single(pi) * single(-0.25))));
end
\begin{array}{l}

\\
-4 \cdot \left(\pi \cdot \left(0.25 + u \cdot -0.25\right) + u \cdot \left(\pi \cdot -0.25\right)\right)
\end{array}
Derivation
  1. Initial program 98.9%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.9%

    \[\leadsto \color{blue}{s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around -inf 12.0%

    \[\leadsto \color{blue}{-4 \cdot \left(-0.25 \cdot \left(u \cdot \pi\right) - \left(-0.25 \cdot \pi + 0.25 \cdot \left(u \cdot \pi\right)\right)\right)} \]
  5. Step-by-step derivation
    1. associate--r+12.0%

      \[\leadsto -4 \cdot \color{blue}{\left(\left(-0.25 \cdot \left(u \cdot \pi\right) - -0.25 \cdot \pi\right) - 0.25 \cdot \left(u \cdot \pi\right)\right)} \]
    2. cancel-sign-sub-inv12.0%

      \[\leadsto -4 \cdot \left(\color{blue}{\left(-0.25 \cdot \left(u \cdot \pi\right) + \left(--0.25\right) \cdot \pi\right)} - 0.25 \cdot \left(u \cdot \pi\right)\right) \]
    3. metadata-eval12.0%

      \[\leadsto -4 \cdot \left(\left(-0.25 \cdot \left(u \cdot \pi\right) + \color{blue}{0.25} \cdot \pi\right) - 0.25 \cdot \left(u \cdot \pi\right)\right) \]
    4. cancel-sign-sub-inv12.0%

      \[\leadsto -4 \cdot \color{blue}{\left(\left(-0.25 \cdot \left(u \cdot \pi\right) + 0.25 \cdot \pi\right) + \left(-0.25\right) \cdot \left(u \cdot \pi\right)\right)} \]
    5. associate-*r*12.0%

      \[\leadsto -4 \cdot \left(\left(\color{blue}{\left(-0.25 \cdot u\right) \cdot \pi} + 0.25 \cdot \pi\right) + \left(-0.25\right) \cdot \left(u \cdot \pi\right)\right) \]
    6. distribute-rgt-out12.0%

      \[\leadsto -4 \cdot \left(\color{blue}{\pi \cdot \left(-0.25 \cdot u + 0.25\right)} + \left(-0.25\right) \cdot \left(u \cdot \pi\right)\right) \]
    7. *-commutative12.0%

      \[\leadsto -4 \cdot \left(\pi \cdot \left(\color{blue}{u \cdot -0.25} + 0.25\right) + \left(-0.25\right) \cdot \left(u \cdot \pi\right)\right) \]
    8. metadata-eval12.0%

      \[\leadsto -4 \cdot \left(\pi \cdot \left(u \cdot -0.25 + 0.25\right) + \color{blue}{-0.25} \cdot \left(u \cdot \pi\right)\right) \]
    9. *-commutative12.0%

      \[\leadsto -4 \cdot \left(\pi \cdot \left(u \cdot -0.25 + 0.25\right) + \color{blue}{\left(u \cdot \pi\right) \cdot -0.25}\right) \]
    10. associate-*l*12.0%

      \[\leadsto -4 \cdot \left(\pi \cdot \left(u \cdot -0.25 + 0.25\right) + \color{blue}{u \cdot \left(\pi \cdot -0.25\right)}\right) \]
  6. Simplified12.0%

    \[\leadsto \color{blue}{-4 \cdot \left(\pi \cdot \left(u \cdot -0.25 + 0.25\right) + u \cdot \left(\pi \cdot -0.25\right)\right)} \]
  7. Final simplification12.0%

    \[\leadsto -4 \cdot \left(\pi \cdot \left(0.25 + u \cdot -0.25\right) + u \cdot \left(\pi \cdot -0.25\right)\right) \]
  8. Add Preprocessing

Alternative 7: 11.7% accurate, 39.4× speedup?

\[\begin{array}{l} \\ 4 \cdot \left(\pi \cdot -0.25 + 0.5 \cdot \left(u \cdot \pi\right)\right) \end{array} \]
(FPCore (u s) :precision binary32 (* 4.0 (+ (* PI -0.25) (* 0.5 (* u PI)))))
float code(float u, float s) {
	return 4.0f * ((((float) M_PI) * -0.25f) + (0.5f * (u * ((float) M_PI))));
}
function code(u, s)
	return Float32(Float32(4.0) * Float32(Float32(Float32(pi) * Float32(-0.25)) + Float32(Float32(0.5) * Float32(u * Float32(pi)))))
end
function tmp = code(u, s)
	tmp = single(4.0) * ((single(pi) * single(-0.25)) + (single(0.5) * (u * single(pi))));
end
\begin{array}{l}

\\
4 \cdot \left(\pi \cdot -0.25 + 0.5 \cdot \left(u \cdot \pi\right)\right)
\end{array}
Derivation
  1. Initial program 98.9%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.9%

    \[\leadsto \color{blue}{s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around inf 12.0%

    \[\leadsto \color{blue}{4 \cdot \left(0.25 \cdot \left(u \cdot \pi\right) - \left(-0.25 \cdot \left(u \cdot \pi\right) + 0.25 \cdot \pi\right)\right)} \]
  5. Step-by-step derivation
    1. associate--r+12.0%

      \[\leadsto 4 \cdot \color{blue}{\left(\left(0.25 \cdot \left(u \cdot \pi\right) - -0.25 \cdot \left(u \cdot \pi\right)\right) - 0.25 \cdot \pi\right)} \]
    2. cancel-sign-sub-inv12.0%

      \[\leadsto 4 \cdot \color{blue}{\left(\left(0.25 \cdot \left(u \cdot \pi\right) - -0.25 \cdot \left(u \cdot \pi\right)\right) + \left(-0.25\right) \cdot \pi\right)} \]
    3. distribute-rgt-out--12.0%

      \[\leadsto 4 \cdot \left(\color{blue}{\left(u \cdot \pi\right) \cdot \left(0.25 - -0.25\right)} + \left(-0.25\right) \cdot \pi\right) \]
    4. *-commutative12.0%

      \[\leadsto 4 \cdot \left(\color{blue}{\left(\pi \cdot u\right)} \cdot \left(0.25 - -0.25\right) + \left(-0.25\right) \cdot \pi\right) \]
    5. metadata-eval12.0%

      \[\leadsto 4 \cdot \left(\left(\pi \cdot u\right) \cdot \color{blue}{0.5} + \left(-0.25\right) \cdot \pi\right) \]
    6. metadata-eval12.0%

      \[\leadsto 4 \cdot \left(\left(\pi \cdot u\right) \cdot 0.5 + \color{blue}{-0.25} \cdot \pi\right) \]
    7. *-commutative12.0%

      \[\leadsto 4 \cdot \left(\left(\pi \cdot u\right) \cdot 0.5 + \color{blue}{\pi \cdot -0.25}\right) \]
  6. Simplified12.0%

    \[\leadsto \color{blue}{4 \cdot \left(\left(\pi \cdot u\right) \cdot 0.5 + \pi \cdot -0.25\right)} \]
  7. Final simplification12.0%

    \[\leadsto 4 \cdot \left(\pi \cdot -0.25 + 0.5 \cdot \left(u \cdot \pi\right)\right) \]
  8. Add Preprocessing

Alternative 8: 11.7% accurate, 48.1× speedup?

\[\begin{array}{l} \\ 4 \cdot \left(\pi \cdot \left(u \cdot 0.5 + -0.25\right)\right) \end{array} \]
(FPCore (u s) :precision binary32 (* 4.0 (* PI (+ (* u 0.5) -0.25))))
float code(float u, float s) {
	return 4.0f * (((float) M_PI) * ((u * 0.5f) + -0.25f));
}
function code(u, s)
	return Float32(Float32(4.0) * Float32(Float32(pi) * Float32(Float32(u * Float32(0.5)) + Float32(-0.25))))
end
function tmp = code(u, s)
	tmp = single(4.0) * (single(pi) * ((u * single(0.5)) + single(-0.25)));
end
\begin{array}{l}

\\
4 \cdot \left(\pi \cdot \left(u \cdot 0.5 + -0.25\right)\right)
\end{array}
Derivation
  1. Initial program 98.9%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.9%

    \[\leadsto \color{blue}{s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around inf 12.0%

    \[\leadsto \color{blue}{4 \cdot \left(0.25 \cdot \left(u \cdot \pi\right) - \left(-0.25 \cdot \left(u \cdot \pi\right) + 0.25 \cdot \pi\right)\right)} \]
  5. Step-by-step derivation
    1. associate--r+12.0%

      \[\leadsto 4 \cdot \color{blue}{\left(\left(0.25 \cdot \left(u \cdot \pi\right) - -0.25 \cdot \left(u \cdot \pi\right)\right) - 0.25 \cdot \pi\right)} \]
    2. cancel-sign-sub-inv12.0%

      \[\leadsto 4 \cdot \color{blue}{\left(\left(0.25 \cdot \left(u \cdot \pi\right) - -0.25 \cdot \left(u \cdot \pi\right)\right) + \left(-0.25\right) \cdot \pi\right)} \]
    3. distribute-rgt-out--12.0%

      \[\leadsto 4 \cdot \left(\color{blue}{\left(u \cdot \pi\right) \cdot \left(0.25 - -0.25\right)} + \left(-0.25\right) \cdot \pi\right) \]
    4. *-commutative12.0%

      \[\leadsto 4 \cdot \left(\color{blue}{\left(\pi \cdot u\right)} \cdot \left(0.25 - -0.25\right) + \left(-0.25\right) \cdot \pi\right) \]
    5. metadata-eval12.0%

      \[\leadsto 4 \cdot \left(\left(\pi \cdot u\right) \cdot \color{blue}{0.5} + \left(-0.25\right) \cdot \pi\right) \]
    6. metadata-eval12.0%

      \[\leadsto 4 \cdot \left(\left(\pi \cdot u\right) \cdot 0.5 + \color{blue}{-0.25} \cdot \pi\right) \]
    7. *-commutative12.0%

      \[\leadsto 4 \cdot \left(\left(\pi \cdot u\right) \cdot 0.5 + \color{blue}{\pi \cdot -0.25}\right) \]
  6. Simplified12.0%

    \[\leadsto \color{blue}{4 \cdot \left(\left(\pi \cdot u\right) \cdot 0.5 + \pi \cdot -0.25\right)} \]
  7. Taylor expanded in u around 0 12.0%

    \[\leadsto 4 \cdot \color{blue}{\left(-0.25 \cdot \pi + 0.5 \cdot \left(u \cdot \pi\right)\right)} \]
  8. Step-by-step derivation
    1. +-commutative12.0%

      \[\leadsto 4 \cdot \color{blue}{\left(0.5 \cdot \left(u \cdot \pi\right) + -0.25 \cdot \pi\right)} \]
    2. associate-*r*12.0%

      \[\leadsto 4 \cdot \left(\color{blue}{\left(0.5 \cdot u\right) \cdot \pi} + -0.25 \cdot \pi\right) \]
    3. distribute-rgt-out12.0%

      \[\leadsto 4 \cdot \color{blue}{\left(\pi \cdot \left(0.5 \cdot u + -0.25\right)\right)} \]
  9. Simplified12.0%

    \[\leadsto 4 \cdot \color{blue}{\left(\pi \cdot \left(0.5 \cdot u + -0.25\right)\right)} \]
  10. Final simplification12.0%

    \[\leadsto 4 \cdot \left(\pi \cdot \left(u \cdot 0.5 + -0.25\right)\right) \]
  11. Add Preprocessing

Alternative 9: 11.4% accurate, 216.5× speedup?

\[\begin{array}{l} \\ -\pi \end{array} \]
(FPCore (u s) :precision binary32 (- PI))
float code(float u, float s) {
	return -((float) M_PI);
}
function code(u, s)
	return Float32(-Float32(pi))
end
function tmp = code(u, s)
	tmp = -single(pi);
end
\begin{array}{l}

\\
-\pi
\end{array}
Derivation
  1. Initial program 98.9%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.9%

    \[\leadsto \color{blue}{s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in u around 0 11.8%

    \[\leadsto \color{blue}{-1 \cdot \pi} \]
  5. Step-by-step derivation
    1. neg-mul-111.8%

      \[\leadsto \color{blue}{-\pi} \]
  6. Simplified11.8%

    \[\leadsto \color{blue}{-\pi} \]
  7. Final simplification11.8%

    \[\leadsto -\pi \]
  8. Add Preprocessing

Alternative 10: 4.6% accurate, 433.0× speedup?

\[\begin{array}{l} \\ \pi \end{array} \]
(FPCore (u s) :precision binary32 PI)
float code(float u, float s) {
	return (float) M_PI;
}
function code(u, s)
	return Float32(pi)
end
function tmp = code(u, s)
	tmp = single(pi);
end
\begin{array}{l}

\\
\pi
\end{array}
Derivation
  1. Initial program 98.9%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.9%

    \[\leadsto \color{blue}{s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around inf 37.8%

    \[\leadsto s \cdot \left(-\log \left(\frac{1}{\frac{u}{1 + \color{blue}{1}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)\right) \]
  5. Taylor expanded in u around 0 11.8%

    \[\leadsto s \cdot \left(-\color{blue}{\frac{\pi}{s}}\right) \]
  6. Step-by-step derivation
    1. expm1-log1p-u-0.0%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(s \cdot \left(-\frac{\pi}{s}\right)\right)\right)} \]
    2. expm1-udef-0.0%

      \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(s \cdot \left(-\frac{\pi}{s}\right)\right)} - 1} \]
    3. add-sqr-sqrt-0.0%

      \[\leadsto e^{\mathsf{log1p}\left(s \cdot \color{blue}{\left(\sqrt{-\frac{\pi}{s}} \cdot \sqrt{-\frac{\pi}{s}}\right)}\right)} - 1 \]
    4. sqrt-unprod3.2%

      \[\leadsto e^{\mathsf{log1p}\left(s \cdot \color{blue}{\sqrt{\left(-\frac{\pi}{s}\right) \cdot \left(-\frac{\pi}{s}\right)}}\right)} - 1 \]
    5. sqr-neg3.2%

      \[\leadsto e^{\mathsf{log1p}\left(s \cdot \sqrt{\color{blue}{\frac{\pi}{s} \cdot \frac{\pi}{s}}}\right)} - 1 \]
    6. sqrt-unprod4.5%

      \[\leadsto e^{\mathsf{log1p}\left(s \cdot \color{blue}{\left(\sqrt{\frac{\pi}{s}} \cdot \sqrt{\frac{\pi}{s}}\right)}\right)} - 1 \]
    7. add-sqr-sqrt4.5%

      \[\leadsto e^{\mathsf{log1p}\left(s \cdot \color{blue}{\frac{\pi}{s}}\right)} - 1 \]
  7. Applied egg-rr4.5%

    \[\leadsto \color{blue}{e^{\mathsf{log1p}\left(s \cdot \frac{\pi}{s}\right)} - 1} \]
  8. Step-by-step derivation
    1. expm1-def4.5%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(s \cdot \frac{\pi}{s}\right)\right)} \]
    2. expm1-log1p4.5%

      \[\leadsto \color{blue}{s \cdot \frac{\pi}{s}} \]
  9. Simplified4.5%

    \[\leadsto \color{blue}{s \cdot \frac{\pi}{s}} \]
  10. Taylor expanded in s around 0 4.5%

    \[\leadsto \color{blue}{\pi} \]
  11. Final simplification4.5%

    \[\leadsto \pi \]
  12. Add Preprocessing

Reproduce

?
herbie shell --seed 2024029 
(FPCore (u s)
  :name "Sample trimmed logistic on [-pi, pi]"
  :precision binary32
  :pre (and (and (<= 2.328306437e-10 u) (<= u 1.0)) (and (<= 0.0 s) (<= s 1.0651631)))
  (* (- s) (log (- (/ 1.0 (+ (* u (- (/ 1.0 (+ 1.0 (exp (/ (- PI) s)))) (/ 1.0 (+ 1.0 (exp (/ PI s)))))) (/ 1.0 (+ 1.0 (exp (/ PI s)))))) 1.0))))