Sample trimmed logistic on [-pi, pi]

Percentage Accurate: 98.9% → 98.9%
Time: 46.7s
Alternatives: 9
Speedup: 0.7×

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 9 alternatives:

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

Initial Program: 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, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{u}{1 + e^{\frac{-\pi}{s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}\\ \left(-s\right) \cdot \mathsf{log1p}\left(\frac{{t\_0}^{-2} - 4}{\frac{1}{t\_0} - -2}\right) \end{array} \end{array} \]
(FPCore (u s)
 :precision binary32
 (let* ((t_0
         (+
          (/ u (+ 1.0 (exp (/ (- PI) s))))
          (/ (- 1.0 u) (+ 1.0 (pow (exp (/ 1.0 s)) PI))))))
   (* (- s) (log1p (/ (- (pow t_0 -2.0) 4.0) (- (/ 1.0 t_0) -2.0))))))
float code(float u, float s) {
	float t_0 = (u / (1.0f + expf((-((float) M_PI) / s)))) + ((1.0f - u) / (1.0f + powf(expf((1.0f / s)), ((float) M_PI))));
	return -s * log1pf(((powf(t_0, -2.0f) - 4.0f) / ((1.0f / t_0) - -2.0f)));
}
function code(u, s)
	t_0 = Float32(Float32(u / Float32(Float32(1.0) + exp(Float32(Float32(-Float32(pi)) / s)))) + Float32(Float32(Float32(1.0) - u) / Float32(Float32(1.0) + (exp(Float32(Float32(1.0) / s)) ^ Float32(pi)))))
	return Float32(Float32(-s) * log1p(Float32(Float32((t_0 ^ Float32(-2.0)) - Float32(4.0)) / Float32(Float32(Float32(1.0) / t_0) - Float32(-2.0)))))
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{u}{1 + e^{\frac{-\pi}{s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}\\
\left(-s\right) \cdot \mathsf{log1p}\left(\frac{{t\_0}^{-2} - 4}{\frac{1}{t\_0} - -2}\right)
\end{array}
\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%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Step-by-step derivation
    1. clear-num98.9%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{\frac{s}{\pi}}}}}} + -1\right) \]
    2. inv-pow98.9%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{{\left(\frac{s}{\pi}\right)}^{-1}}}}} + -1\right) \]
  5. Applied egg-rr98.9%

    \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{{\left(\frac{s}{\pi}\right)}^{-1}}}}} + -1\right) \]
  6. Step-by-step derivation
    1. unpow-198.9%

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

    \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{\frac{s}{\pi}}}}}} + -1\right) \]
  8. Step-by-step derivation
    1. log1p-expm1-u98.9%

      \[\leadsto \left(-s\right) \cdot \color{blue}{\mathsf{log1p}\left(\mathsf{expm1}\left(\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{1}{\frac{s}{\pi}}}}} + -1\right)\right)\right)} \]
    2. expm1-undefine98.9%

      \[\leadsto \left(-s\right) \cdot \mathsf{log1p}\left(\color{blue}{e^{\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{1}{\frac{s}{\pi}}}}} + -1\right)} - 1}\right) \]
  9. Applied egg-rr98.9%

    \[\leadsto \left(-s\right) \cdot \color{blue}{\mathsf{log1p}\left(\left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} + -1\right) - 1\right)} \]
  10. Step-by-step derivation
    1. associate--l+98.9%

      \[\leadsto \left(-s\right) \cdot \mathsf{log1p}\left(\color{blue}{\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} + \left(-1 - 1\right)}\right) \]
    2. metadata-eval98.9%

      \[\leadsto \left(-s\right) \cdot \mathsf{log1p}\left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} + \color{blue}{-2}\right) \]
  11. Simplified98.9%

    \[\leadsto \left(-s\right) \cdot \color{blue}{\mathsf{log1p}\left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} + -2\right)} \]
  12. Step-by-step derivation
    1. flip-+98.9%

      \[\leadsto \left(-s\right) \cdot \mathsf{log1p}\left(\color{blue}{\frac{\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} \cdot \frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} - -2 \cdot -2}{\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} - -2}}\right) \]
  13. Applied egg-rr99.0%

    \[\leadsto \left(-s\right) \cdot \mathsf{log1p}\left(\color{blue}{\frac{{\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}\right)}^{-2} - 4}{\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} - -2}}\right) \]
  14. Final simplification99.0%

    \[\leadsto \left(-s\right) \cdot \mathsf{log1p}\left(\frac{{\left(\frac{u}{1 + e^{\frac{-\pi}{s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}\right)}^{-2} - 4}{\frac{1}{\frac{u}{1 + e^{\frac{-\pi}{s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} - -2}\right) \]
  15. Add Preprocessing

Alternative 2: 98.9% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{u}{1 + e^{\frac{-\pi}{s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\\ \left(-s\right) \cdot \mathsf{log1p}\left(\frac{-4 + {t\_0}^{-2}}{2 + \frac{1}{t\_0}}\right) \end{array} \end{array} \]
(FPCore (u s)
 :precision binary32
 (let* ((t_0
         (+
          (/ u (+ 1.0 (exp (/ (- PI) s))))
          (/ (- 1.0 u) (+ 1.0 (exp (/ PI s)))))))
   (* (- s) (log1p (/ (+ -4.0 (pow t_0 -2.0)) (+ 2.0 (/ 1.0 t_0)))))))
float code(float u, float s) {
	float t_0 = (u / (1.0f + expf((-((float) M_PI) / s)))) + ((1.0f - u) / (1.0f + expf((((float) M_PI) / s))));
	return -s * log1pf(((-4.0f + powf(t_0, -2.0f)) / (2.0f + (1.0f / t_0))));
}
function code(u, s)
	t_0 = Float32(Float32(u / Float32(Float32(1.0) + exp(Float32(Float32(-Float32(pi)) / s)))) + Float32(Float32(Float32(1.0) - u) / Float32(Float32(1.0) + exp(Float32(Float32(pi) / s)))))
	return Float32(Float32(-s) * log1p(Float32(Float32(Float32(-4.0) + (t_0 ^ Float32(-2.0))) / Float32(Float32(2.0) + Float32(Float32(1.0) / t_0)))))
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{u}{1 + e^{\frac{-\pi}{s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\\
\left(-s\right) \cdot \mathsf{log1p}\left(\frac{-4 + {t\_0}^{-2}}{2 + \frac{1}{t\_0}}\right)
\end{array}
\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%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Step-by-step derivation
    1. clear-num98.9%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{\frac{s}{\pi}}}}}} + -1\right) \]
    2. inv-pow98.9%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{{\left(\frac{s}{\pi}\right)}^{-1}}}}} + -1\right) \]
  5. Applied egg-rr98.9%

    \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{{\left(\frac{s}{\pi}\right)}^{-1}}}}} + -1\right) \]
  6. Step-by-step derivation
    1. unpow-198.9%

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

    \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{\frac{s}{\pi}}}}}} + -1\right) \]
  8. Step-by-step derivation
    1. log1p-expm1-u98.9%

      \[\leadsto \left(-s\right) \cdot \color{blue}{\mathsf{log1p}\left(\mathsf{expm1}\left(\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{1}{\frac{s}{\pi}}}}} + -1\right)\right)\right)} \]
    2. expm1-undefine98.9%

      \[\leadsto \left(-s\right) \cdot \mathsf{log1p}\left(\color{blue}{e^{\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{1}{\frac{s}{\pi}}}}} + -1\right)} - 1}\right) \]
  9. Applied egg-rr98.9%

    \[\leadsto \left(-s\right) \cdot \color{blue}{\mathsf{log1p}\left(\left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} + -1\right) - 1\right)} \]
  10. Step-by-step derivation
    1. associate--l+98.9%

      \[\leadsto \left(-s\right) \cdot \mathsf{log1p}\left(\color{blue}{\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} + \left(-1 - 1\right)}\right) \]
    2. metadata-eval98.9%

      \[\leadsto \left(-s\right) \cdot \mathsf{log1p}\left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} + \color{blue}{-2}\right) \]
  11. Simplified98.9%

    \[\leadsto \left(-s\right) \cdot \color{blue}{\mathsf{log1p}\left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} + -2\right)} \]
  12. Step-by-step derivation
    1. flip-+98.9%

      \[\leadsto \left(-s\right) \cdot \mathsf{log1p}\left(\color{blue}{\frac{\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} \cdot \frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} - -2 \cdot -2}{\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} - -2}}\right) \]
  13. Applied egg-rr99.0%

    \[\leadsto \left(-s\right) \cdot \mathsf{log1p}\left(\color{blue}{\frac{{\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}\right)}^{-2} - 4}{\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} - -2}}\right) \]
  14. Step-by-step derivation
    1. *-un-lft-identity99.0%

      \[\leadsto \left(-s\right) \cdot \color{blue}{\left(1 \cdot \mathsf{log1p}\left(\frac{{\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}\right)}^{-2} - 4}{\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}} - -2}\right)\right)} \]
  15. Applied egg-rr99.0%

    \[\leadsto \left(-s\right) \cdot \color{blue}{\left(1 \cdot \mathsf{log1p}\left(\frac{{\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-2} + -4}{\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + 2}\right)\right)} \]
  16. Step-by-step derivation
    1. *-lft-identity99.0%

      \[\leadsto \left(-s\right) \cdot \color{blue}{\mathsf{log1p}\left(\frac{{\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-2} + -4}{\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + 2}\right)} \]
    2. +-commutative99.0%

      \[\leadsto \left(-s\right) \cdot \mathsf{log1p}\left(\frac{\color{blue}{-4 + {\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-2}}}{\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + 2}\right) \]
    3. +-commutative99.0%

      \[\leadsto \left(-s\right) \cdot \mathsf{log1p}\left(\frac{-4 + {\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-2}}{\color{blue}{2 + \frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}}}}\right) \]
  17. Simplified99.0%

    \[\leadsto \left(-s\right) \cdot \color{blue}{\mathsf{log1p}\left(\frac{-4 + {\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-2}}{2 + \frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}}}\right)} \]
  18. Final simplification99.0%

    \[\leadsto \left(-s\right) \cdot \mathsf{log1p}\left(\frac{-4 + {\left(\frac{u}{1 + e^{\frac{-\pi}{s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-2}}{2 + \frac{1}{\frac{u}{1 + e^{\frac{-\pi}{s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}}}\right) \]
  19. Add Preprocessing

Alternative 3: 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(-Float32(pi)) / 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%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  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 4: 25.1% accurate, 3.7× speedup?

\[\begin{array}{l} \\ s \cdot \left(-\log \left(1 + 4 \cdot \frac{-0.25 \cdot \left(u \cdot \pi\right) - \pi \cdot -0.25}{s}\right)\right) \end{array} \]
(FPCore (u s)
 :precision binary32
 (* s (- (log (+ 1.0 (* 4.0 (/ (- (* -0.25 (* u PI)) (* PI -0.25)) s)))))))
float code(float u, float s) {
	return s * -logf((1.0f + (4.0f * (((-0.25f * (u * ((float) M_PI))) - (((float) M_PI) * -0.25f)) / s))));
}
function code(u, s)
	return Float32(s * Float32(-log(Float32(Float32(1.0) + Float32(Float32(4.0) * Float32(Float32(Float32(Float32(-0.25) * Float32(u * Float32(pi))) - Float32(Float32(pi) * Float32(-0.25))) / s))))))
end
function tmp = code(u, s)
	tmp = s * -log((single(1.0) + (single(4.0) * (((single(-0.25) * (u * single(pi))) - (single(pi) * single(-0.25))) / s))));
end
\begin{array}{l}

\\
s \cdot \left(-\log \left(1 + 4 \cdot \frac{-0.25 \cdot \left(u \cdot \pi\right) - \pi \cdot -0.25}{s}\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%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around -inf 25.9%

    \[\leadsto \left(-s\right) \cdot \log \color{blue}{\left(1 + 4 \cdot \frac{-0.25 \cdot \left(u \cdot \pi\right) - \left(-0.25 \cdot \pi + 0.25 \cdot \left(u \cdot \pi\right)\right)}{s}\right)} \]
  5. Taylor expanded in u around 0 26.0%

    \[\leadsto \left(-s\right) \cdot \log \left(1 + 4 \cdot \frac{-0.25 \cdot \left(u \cdot \pi\right) - \color{blue}{-0.25 \cdot \pi}}{s}\right) \]
  6. Step-by-step derivation
    1. *-commutative26.0%

      \[\leadsto \left(-s\right) \cdot \log \left(1 + 4 \cdot \frac{-0.25 \cdot \left(u \cdot \pi\right) - \color{blue}{\pi \cdot -0.25}}{s}\right) \]
  7. Simplified26.0%

    \[\leadsto \left(-s\right) \cdot \log \left(1 + 4 \cdot \frac{-0.25 \cdot \left(u \cdot \pi\right) - \color{blue}{\pi \cdot -0.25}}{s}\right) \]
  8. Final simplification26.0%

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

Alternative 5: 25.1% accurate, 3.9× speedup?

\[\begin{array}{l} \\ \left(-s\right) \cdot \log \left(1 + 4 \cdot \left(\frac{\pi}{s} \cdot 0.25\right)\right) \end{array} \]
(FPCore (u s)
 :precision binary32
 (* (- s) (log (+ 1.0 (* 4.0 (* (/ PI s) 0.25))))))
float code(float u, float s) {
	return -s * logf((1.0f + (4.0f * ((((float) M_PI) / s) * 0.25f))));
}
function code(u, s)
	return Float32(Float32(-s) * log(Float32(Float32(1.0) + Float32(Float32(4.0) * Float32(Float32(Float32(pi) / s) * Float32(0.25))))))
end
function tmp = code(u, s)
	tmp = -s * log((single(1.0) + (single(4.0) * ((single(pi) / s) * single(0.25)))));
end
\begin{array}{l}

\\
\left(-s\right) \cdot \log \left(1 + 4 \cdot \left(\frac{\pi}{s} \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%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around -inf 25.9%

    \[\leadsto \left(-s\right) \cdot \log \color{blue}{\left(1 + 4 \cdot \frac{-0.25 \cdot \left(u \cdot \pi\right) - \left(-0.25 \cdot \pi + 0.25 \cdot \left(u \cdot \pi\right)\right)}{s}\right)} \]
  5. Taylor expanded in u around 0 26.0%

    \[\leadsto \left(-s\right) \cdot \log \left(1 + 4 \cdot \color{blue}{\left(0.25 \cdot \frac{\pi}{s}\right)}\right) \]
  6. Step-by-step derivation
    1. *-commutative26.0%

      \[\leadsto \left(-s\right) \cdot \log \left(1 + 4 \cdot \color{blue}{\left(\frac{\pi}{s} \cdot 0.25\right)}\right) \]
  7. Simplified26.0%

    \[\leadsto \left(-s\right) \cdot \log \left(1 + 4 \cdot \color{blue}{\left(\frac{\pi}{s} \cdot 0.25\right)}\right) \]
  8. Add Preprocessing

Alternative 6: 11.5% accurate, 3.9× speedup?

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

\\
-4 \cdot \left(\pi \cdot \left(\mathsf{fma}\left(u, -0.25, 0.25\right) + u \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%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around -inf 11.7%

    \[\leadsto \color{blue}{-4 \cdot \left(-0.25 \cdot \left(u \cdot \pi\right) - \left(-0.25 \cdot \pi + 0.25 \cdot \left(u \cdot \pi\right)\right)\right)} \]
  5. Step-by-step derivation
    1. associate--r+11.7%

      \[\leadsto -4 \cdot \color{blue}{\left(\left(-0.25 \cdot \left(u \cdot \pi\right) - -0.25 \cdot \pi\right) - 0.25 \cdot \left(u \cdot \pi\right)\right)} \]
    2. cancel-sign-sub-inv11.7%

      \[\leadsto -4 \cdot \color{blue}{\left(\left(-0.25 \cdot \left(u \cdot \pi\right) - -0.25 \cdot \pi\right) + \left(-0.25\right) \cdot \left(u \cdot \pi\right)\right)} \]
    3. cancel-sign-sub-inv11.7%

      \[\leadsto -4 \cdot \left(\color{blue}{\left(-0.25 \cdot \left(u \cdot \pi\right) + \left(--0.25\right) \cdot \pi\right)} + \left(-0.25\right) \cdot \left(u \cdot \pi\right)\right) \]
    4. metadata-eval11.7%

      \[\leadsto -4 \cdot \left(\left(-0.25 \cdot \left(u \cdot \pi\right) + \color{blue}{0.25} \cdot \pi\right) + \left(-0.25\right) \cdot \left(u \cdot \pi\right)\right) \]
    5. associate-*r*11.7%

      \[\leadsto -4 \cdot \left(\left(\color{blue}{\left(-0.25 \cdot u\right) \cdot \pi} + 0.25 \cdot \pi\right) + \left(-0.25\right) \cdot \left(u \cdot \pi\right)\right) \]
    6. distribute-rgt-out11.7%

      \[\leadsto -4 \cdot \left(\color{blue}{\pi \cdot \left(-0.25 \cdot u + 0.25\right)} + \left(-0.25\right) \cdot \left(u \cdot \pi\right)\right) \]
    7. metadata-eval11.7%

      \[\leadsto -4 \cdot \left(\pi \cdot \left(-0.25 \cdot u + 0.25\right) + \color{blue}{-0.25} \cdot \left(u \cdot \pi\right)\right) \]
    8. *-commutative11.7%

      \[\leadsto -4 \cdot \left(\pi \cdot \left(-0.25 \cdot u + 0.25\right) + \color{blue}{\left(u \cdot \pi\right) \cdot -0.25}\right) \]
    9. *-commutative11.7%

      \[\leadsto -4 \cdot \left(\pi \cdot \left(-0.25 \cdot u + 0.25\right) + \color{blue}{\left(\pi \cdot u\right)} \cdot -0.25\right) \]
    10. associate-*l*11.7%

      \[\leadsto -4 \cdot \left(\pi \cdot \left(-0.25 \cdot u + 0.25\right) + \color{blue}{\pi \cdot \left(u \cdot -0.25\right)}\right) \]
  6. Simplified11.7%

    \[\leadsto \color{blue}{-4 \cdot \left(\pi \cdot \left(-0.25 \cdot u + 0.25\right) + \pi \cdot \left(u \cdot -0.25\right)\right)} \]
  7. Step-by-step derivation
    1. *-un-lft-identity11.7%

      \[\leadsto -4 \cdot \color{blue}{\left(1 \cdot \left(\pi \cdot \left(-0.25 \cdot u + 0.25\right) + \pi \cdot \left(u \cdot -0.25\right)\right)\right)} \]
    2. distribute-lft-out11.7%

      \[\leadsto -4 \cdot \left(1 \cdot \color{blue}{\left(\pi \cdot \left(\left(-0.25 \cdot u + 0.25\right) + u \cdot -0.25\right)\right)}\right) \]
    3. *-commutative11.7%

      \[\leadsto -4 \cdot \left(1 \cdot \left(\pi \cdot \left(\left(\color{blue}{u \cdot -0.25} + 0.25\right) + u \cdot -0.25\right)\right)\right) \]
    4. fma-define11.7%

      \[\leadsto -4 \cdot \left(1 \cdot \left(\pi \cdot \left(\color{blue}{\mathsf{fma}\left(u, -0.25, 0.25\right)} + u \cdot -0.25\right)\right)\right) \]
  8. Applied egg-rr11.7%

    \[\leadsto -4 \cdot \color{blue}{\left(1 \cdot \left(\pi \cdot \left(\mathsf{fma}\left(u, -0.25, 0.25\right) + u \cdot -0.25\right)\right)\right)} \]
  9. Step-by-step derivation
    1. *-lft-identity11.7%

      \[\leadsto -4 \cdot \color{blue}{\left(\pi \cdot \left(\mathsf{fma}\left(u, -0.25, 0.25\right) + u \cdot -0.25\right)\right)} \]
  10. Simplified11.7%

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

Alternative 7: 11.5% accurate, 61.9× speedup?

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

\\
\pi \cdot \left(-1 + u \cdot 2\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%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around -inf 11.7%

    \[\leadsto \color{blue}{-4 \cdot \left(-0.25 \cdot \left(u \cdot \pi\right) - \left(-0.25 \cdot \pi + 0.25 \cdot \left(u \cdot \pi\right)\right)\right)} \]
  5. Step-by-step derivation
    1. associate--r+11.7%

      \[\leadsto -4 \cdot \color{blue}{\left(\left(-0.25 \cdot \left(u \cdot \pi\right) - -0.25 \cdot \pi\right) - 0.25 \cdot \left(u \cdot \pi\right)\right)} \]
    2. cancel-sign-sub-inv11.7%

      \[\leadsto -4 \cdot \color{blue}{\left(\left(-0.25 \cdot \left(u \cdot \pi\right) - -0.25 \cdot \pi\right) + \left(-0.25\right) \cdot \left(u \cdot \pi\right)\right)} \]
    3. cancel-sign-sub-inv11.7%

      \[\leadsto -4 \cdot \left(\color{blue}{\left(-0.25 \cdot \left(u \cdot \pi\right) + \left(--0.25\right) \cdot \pi\right)} + \left(-0.25\right) \cdot \left(u \cdot \pi\right)\right) \]
    4. metadata-eval11.7%

      \[\leadsto -4 \cdot \left(\left(-0.25 \cdot \left(u \cdot \pi\right) + \color{blue}{0.25} \cdot \pi\right) + \left(-0.25\right) \cdot \left(u \cdot \pi\right)\right) \]
    5. associate-*r*11.7%

      \[\leadsto -4 \cdot \left(\left(\color{blue}{\left(-0.25 \cdot u\right) \cdot \pi} + 0.25 \cdot \pi\right) + \left(-0.25\right) \cdot \left(u \cdot \pi\right)\right) \]
    6. distribute-rgt-out11.7%

      \[\leadsto -4 \cdot \left(\color{blue}{\pi \cdot \left(-0.25 \cdot u + 0.25\right)} + \left(-0.25\right) \cdot \left(u \cdot \pi\right)\right) \]
    7. metadata-eval11.7%

      \[\leadsto -4 \cdot \left(\pi \cdot \left(-0.25 \cdot u + 0.25\right) + \color{blue}{-0.25} \cdot \left(u \cdot \pi\right)\right) \]
    8. *-commutative11.7%

      \[\leadsto -4 \cdot \left(\pi \cdot \left(-0.25 \cdot u + 0.25\right) + \color{blue}{\left(u \cdot \pi\right) \cdot -0.25}\right) \]
    9. *-commutative11.7%

      \[\leadsto -4 \cdot \left(\pi \cdot \left(-0.25 \cdot u + 0.25\right) + \color{blue}{\left(\pi \cdot u\right)} \cdot -0.25\right) \]
    10. associate-*l*11.7%

      \[\leadsto -4 \cdot \left(\pi \cdot \left(-0.25 \cdot u + 0.25\right) + \color{blue}{\pi \cdot \left(u \cdot -0.25\right)}\right) \]
  6. Simplified11.7%

    \[\leadsto \color{blue}{-4 \cdot \left(\pi \cdot \left(-0.25 \cdot u + 0.25\right) + \pi \cdot \left(u \cdot -0.25\right)\right)} \]
  7. Taylor expanded in u around 0 11.7%

    \[\leadsto \color{blue}{-1 \cdot \pi + 2 \cdot \left(u \cdot \pi\right)} \]
  8. Step-by-step derivation
    1. neg-mul-111.7%

      \[\leadsto \color{blue}{\left(-\pi\right)} + 2 \cdot \left(u \cdot \pi\right) \]
    2. +-commutative11.7%

      \[\leadsto \color{blue}{2 \cdot \left(u \cdot \pi\right) + \left(-\pi\right)} \]
    3. associate-*r*11.7%

      \[\leadsto \color{blue}{\left(2 \cdot u\right) \cdot \pi} + \left(-\pi\right) \]
    4. neg-mul-111.7%

      \[\leadsto \left(2 \cdot u\right) \cdot \pi + \color{blue}{-1 \cdot \pi} \]
    5. distribute-rgt-out11.7%

      \[\leadsto \color{blue}{\pi \cdot \left(2 \cdot u + -1\right)} \]
  9. Simplified11.7%

    \[\leadsto \color{blue}{\pi \cdot \left(2 \cdot u + -1\right)} \]
  10. Final simplification11.7%

    \[\leadsto \pi \cdot \left(-1 + u \cdot 2\right) \]
  11. Add Preprocessing

Alternative 8: 11.3% 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%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in u around 0 11.5%

    \[\leadsto \color{blue}{-1 \cdot \pi} \]
  5. Step-by-step derivation
    1. neg-mul-111.5%

      \[\leadsto \color{blue}{-\pi} \]
  6. Simplified11.5%

    \[\leadsto \color{blue}{-\pi} \]
  7. Add Preprocessing

Alternative 9: 10.3% accurate, 433.0× speedup?

\[\begin{array}{l} \\ 0 \end{array} \]
(FPCore (u s) :precision binary32 0.0)
float code(float u, float s) {
	return 0.0f;
}
real(4) function code(u, s)
    real(4), intent (in) :: u
    real(4), intent (in) :: s
    code = 0.0e0
end function
function code(u, s)
	return Float32(0.0)
end
function tmp = code(u, s)
	tmp = single(0.0);
end
\begin{array}{l}

\\
0
\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%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Step-by-step derivation
    1. clear-num98.9%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{\frac{s}{\pi}}}}}} + -1\right) \]
    2. inv-pow98.9%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{{\left(\frac{s}{\pi}\right)}^{-1}}}}} + -1\right) \]
  5. Applied egg-rr98.9%

    \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{{\left(\frac{s}{\pi}\right)}^{-1}}}}} + -1\right) \]
  6. Step-by-step derivation
    1. unpow-198.9%

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

    \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{\frac{s}{\pi}}}}}} + -1\right) \]
  8. Step-by-step derivation
    1. add-exp-log98.8%

      \[\leadsto \left(-s\right) \cdot \log \left(\color{blue}{e^{\log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{1}{\frac{s}{\pi}}}}}\right)}} + -1\right) \]
    2. log-rec98.7%

      \[\leadsto \left(-s\right) \cdot \log \left(e^{\color{blue}{-\log \left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{1}{\frac{s}{\pi}}}}\right)}} + -1\right) \]
    3. associate-/r/98.7%

      \[\leadsto \left(-s\right) \cdot \log \left(e^{-\log \left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{s} \cdot \pi}}}\right)} + -1\right) \]
    4. exp-prod98.7%

      \[\leadsto \left(-s\right) \cdot \log \left(e^{-\log \left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + \color{blue}{{\left(e^{\frac{1}{s}}\right)}^{\pi}}}\right)} + -1\right) \]
  9. Applied egg-rr98.7%

    \[\leadsto \left(-s\right) \cdot \log \left(\color{blue}{e^{-\log \left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + {\left(e^{\frac{1}{s}}\right)}^{\pi}}\right)}} + -1\right) \]
  10. Taylor expanded in s around inf 10.0%

    \[\leadsto \color{blue}{-1 \cdot \left(s \cdot \log \left(e^{-\log 0.5} - 1\right)\right)} \]
  11. Step-by-step derivation
    1. mul-1-neg10.0%

      \[\leadsto \color{blue}{-s \cdot \log \left(e^{-\log 0.5} - 1\right)} \]
    2. distribute-rgt-neg-in10.0%

      \[\leadsto \color{blue}{s \cdot \left(-\log \left(e^{-\log 0.5} - 1\right)\right)} \]
    3. exp-neg10.0%

      \[\leadsto s \cdot \left(-\log \left(\color{blue}{\frac{1}{e^{\log 0.5}}} - 1\right)\right) \]
    4. rem-exp-log10.0%

      \[\leadsto s \cdot \left(-\log \left(\frac{1}{\color{blue}{0.5}} - 1\right)\right) \]
    5. metadata-eval10.0%

      \[\leadsto s \cdot \left(-\log \left(\color{blue}{2} - 1\right)\right) \]
    6. metadata-eval10.0%

      \[\leadsto s \cdot \left(-\log \color{blue}{1}\right) \]
    7. metadata-eval10.0%

      \[\leadsto s \cdot \left(-\color{blue}{0}\right) \]
    8. metadata-eval10.0%

      \[\leadsto s \cdot \color{blue}{0} \]
  12. Simplified10.0%

    \[\leadsto \color{blue}{s \cdot 0} \]
  13. Taylor expanded in s around 0 10.0%

    \[\leadsto \color{blue}{0} \]
  14. Add Preprocessing

Reproduce

?
herbie shell --seed 2024143 
(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))))