Sample trimmed logistic on [-pi, pi]

Percentage Accurate: 99.0% → 99.0%
Time: 21.0s
Alternatives: 11
Speedup: N/A×

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 11 alternatives:

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

Initial Program: 99.0% 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: 99.0% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{\frac{\pi}{s}}\\ t_1 := \frac{u}{1 + e^{\frac{\pi}{-s}}}\\ t_2 := t\_1 + \frac{1 - u}{1 + t\_0}\\ \left(-s\right) \cdot \log \left(\frac{-1 + {t\_2}^{-3}}{{t\_2}^{-2} + \left(1 + \frac{-1}{\frac{1 - u}{-1 - t\_0} - t\_1}\right)}\right) \end{array} \end{array} \]
(FPCore (u s)
 :precision binary32
 (let* ((t_0 (exp (/ PI s)))
        (t_1 (/ u (+ 1.0 (exp (/ PI (- s))))))
        (t_2 (+ t_1 (/ (- 1.0 u) (+ 1.0 t_0)))))
   (*
    (- s)
    (log
     (/
      (+ -1.0 (pow t_2 -3.0))
      (+
       (pow t_2 -2.0)
       (+ 1.0 (/ -1.0 (- (/ (- 1.0 u) (- -1.0 t_0)) t_1)))))))))
float code(float u, float s) {
	float t_0 = expf((((float) M_PI) / s));
	float t_1 = u / (1.0f + expf((((float) M_PI) / -s)));
	float t_2 = t_1 + ((1.0f - u) / (1.0f + t_0));
	return -s * logf(((-1.0f + powf(t_2, -3.0f)) / (powf(t_2, -2.0f) + (1.0f + (-1.0f / (((1.0f - u) / (-1.0f - t_0)) - t_1))))));
}
function code(u, s)
	t_0 = exp(Float32(Float32(pi) / s))
	t_1 = Float32(u / Float32(Float32(1.0) + exp(Float32(Float32(pi) / Float32(-s)))))
	t_2 = Float32(t_1 + Float32(Float32(Float32(1.0) - u) / Float32(Float32(1.0) + t_0)))
	return Float32(Float32(-s) * log(Float32(Float32(Float32(-1.0) + (t_2 ^ Float32(-3.0))) / Float32((t_2 ^ Float32(-2.0)) + Float32(Float32(1.0) + Float32(Float32(-1.0) / Float32(Float32(Float32(Float32(1.0) - u) / Float32(Float32(-1.0) - t_0)) - t_1)))))))
end
function tmp = code(u, s)
	t_0 = exp((single(pi) / s));
	t_1 = u / (single(1.0) + exp((single(pi) / -s)));
	t_2 = t_1 + ((single(1.0) - u) / (single(1.0) + t_0));
	tmp = -s * log(((single(-1.0) + (t_2 ^ single(-3.0))) / ((t_2 ^ single(-2.0)) + (single(1.0) + (single(-1.0) / (((single(1.0) - u) / (single(-1.0) - t_0)) - t_1))))));
end
\begin{array}{l}

\\
\begin{array}{l}
t_0 := e^{\frac{\pi}{s}}\\
t_1 := \frac{u}{1 + e^{\frac{\pi}{-s}}}\\
t_2 := t\_1 + \frac{1 - u}{1 + t\_0}\\
\left(-s\right) \cdot \log \left(\frac{-1 + {t\_2}^{-3}}{{t\_2}^{-2} + \left(1 + \frac{-1}{\frac{1 - u}{-1 - t\_0} - t\_1}\right)}\right)
\end{array}
\end{array}
Derivation
  1. Initial program 98.6%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.6%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Step-by-step derivation
    1. clear-num98.6%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{\frac{s}{\pi}}}}}} + -1\right) \]
    2. associate-/r/98.6%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{s} \cdot \pi}}}} + -1\right) \]
  5. Applied egg-rr98.6%

    \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{s} \cdot \pi}}}} + -1\right) \]
  6. Applied egg-rr98.8%

    \[\leadsto \left(-s\right) \cdot \log \color{blue}{\left(\frac{{\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-3} + -1}{{\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-2} + \left(1 - \frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} \cdot -1\right)}\right)} \]
  7. Step-by-step derivation
    1. +-commutative98.8%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{\color{blue}{-1 + {\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-3}}}{{\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-2} + \left(1 - \frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} \cdot -1\right)}\right) \]
    2. associate-*l/98.8%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{-1 + {\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-3}}{{\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-2} + \left(1 - \color{blue}{\frac{1 \cdot -1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}}}\right)}\right) \]
    3. metadata-eval98.8%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{-1 + {\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-3}}{{\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-2} + \left(1 - \frac{\color{blue}{-1}}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}}\right)}\right) \]
  8. Simplified98.8%

    \[\leadsto \left(-s\right) \cdot \log \color{blue}{\left(\frac{-1 + {\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-3}}{{\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-2} + \left(1 - \frac{-1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}}\right)}\right)} \]
  9. Final simplification98.8%

    \[\leadsto \left(-s\right) \cdot \log \left(\frac{-1 + {\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-3}}{{\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}\right)}^{-2} + \left(1 + \frac{-1}{\frac{1 - u}{-1 - e^{\frac{\pi}{s}}} - \frac{u}{1 + e^{\frac{\pi}{-s}}}}\right)}\right) \]
  10. Add Preprocessing

Alternative 2: 98.8% accurate, 0.8× speedup?

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

\\
\left(-s\right) \cdot \log \left(-1 + {\left(\sqrt{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}}\right)}^{-2}\right)
\end{array}
Derivation
  1. Initial program 98.6%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.6%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Step-by-step derivation
    1. clear-num98.6%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{\frac{s}{\pi}}}}}} + -1\right) \]
    2. associate-/r/98.6%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{s} \cdot \pi}}}} + -1\right) \]
  5. Applied egg-rr98.6%

    \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{s} \cdot \pi}}}} + -1\right) \]
  6. Step-by-step derivation
    1. inv-pow98.6%

      \[\leadsto \left(-s\right) \cdot \log \left(\color{blue}{{\left(\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{1}{s} \cdot \pi}}\right)}^{-1}} + -1\right) \]
    2. add-sqr-sqrt98.6%

      \[\leadsto \left(-s\right) \cdot \log \left({\color{blue}{\left(\sqrt{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{1}{s} \cdot \pi}}} \cdot \sqrt{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{1}{s} \cdot \pi}}}\right)}}^{-1} + -1\right) \]
    3. unpow-prod-down98.6%

      \[\leadsto \left(-s\right) \cdot \log \left(\color{blue}{{\left(\sqrt{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{1}{s} \cdot \pi}}}\right)}^{-1} \cdot {\left(\sqrt{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{1}{s} \cdot \pi}}}\right)}^{-1}} + -1\right) \]
  7. Applied egg-rr98.6%

    \[\leadsto \left(-s\right) \cdot \log \left(\color{blue}{{\left(\sqrt{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}}\right)}^{-1} \cdot {\left(\sqrt{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}}\right)}^{-1}} + -1\right) \]
  8. Step-by-step derivation
    1. pow-sqr98.7%

      \[\leadsto \left(-s\right) \cdot \log \left(\color{blue}{{\left(\sqrt{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}}\right)}^{\left(2 \cdot -1\right)}} + -1\right) \]
    2. metadata-eval98.7%

      \[\leadsto \left(-s\right) \cdot \log \left({\left(\sqrt{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}}\right)}^{\color{blue}{-2}} + -1\right) \]
  9. Simplified98.7%

    \[\leadsto \left(-s\right) \cdot \log \left(\color{blue}{{\left(\sqrt{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}}\right)}^{-2}} + -1\right) \]
  10. Final simplification98.7%

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

Alternative 3: 99.0% accurate, 1.3× speedup?

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

\\
\left(-s\right) \cdot \log \left(-1 + \frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\pi \cdot \frac{1}{s}}}}\right)
\end{array}
Derivation
  1. Initial program 98.6%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.6%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Step-by-step derivation
    1. clear-num98.6%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{\frac{s}{\pi}}}}}} + -1\right) \]
    2. associate-/r/98.6%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{s} \cdot \pi}}}} + -1\right) \]
  5. Applied egg-rr98.6%

    \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\color{blue}{\frac{1}{s} \cdot \pi}}}} + -1\right) \]
  6. Final simplification98.6%

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

Alternative 4: 99.0% accurate, 1.3× speedup?

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

\\
\left(-s\right) \cdot \log \left(-1 + \frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}}\right)
\end{array}
Derivation
  1. Initial program 98.6%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.6%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Final simplification98.6%

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

Alternative 5: 97.4% accurate, 2.0× speedup?

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

\\
s \cdot \left(-\log \left(-1 + \frac{1 + e^{\frac{\pi}{-s}}}{u}\right)\right)
\end{array}
Derivation
  1. Initial program 98.6%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.6%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around inf 86.0%

    \[\leadsto \left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + \color{blue}{\left(1 + \frac{\pi}{s}\right)}}} + -1\right) \]
  5. Taylor expanded in s around 0 97.1%

    \[\leadsto \left(-s\right) \cdot \log \left(\color{blue}{\frac{1 + e^{-1 \cdot \frac{\pi}{s}}}{u}} + -1\right) \]
  6. Step-by-step derivation
    1. mul-1-neg97.1%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{1 + e^{\color{blue}{-\frac{\pi}{s}}}}{u} + -1\right) \]
    2. distribute-frac-neg297.1%

      \[\leadsto \left(-s\right) \cdot \log \left(\frac{1 + e^{\color{blue}{\frac{\pi}{-s}}}}{u} + -1\right) \]
  7. Simplified97.1%

    \[\leadsto \left(-s\right) \cdot \log \left(\color{blue}{\frac{1 + e^{\frac{\pi}{-s}}}{u}} + -1\right) \]
  8. Final simplification97.1%

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

Alternative 6: 25.0% accurate, 3.3× speedup?

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

\\
-4 \cdot \frac{s \cdot \left(u \cdot \left(\frac{\pi}{s} \cdot 0.25 - \frac{\pi}{s} \cdot -0.25\right)\right)}{-1 + \frac{\pi}{s}} - s \cdot \log \left(1 + \frac{\pi}{s}\right)
\end{array}
Derivation
  1. Initial program 98.6%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.6%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around -inf 25.4%

    \[\leadsto \left(-s\right) \cdot \log \color{blue}{\left(1 + 4 \cdot \frac{-0.25 \cdot \left(u \cdot \pi\right) - \left(-0.25 \cdot \pi + 0.25 \cdot \left(u \cdot \pi\right)\right)}{s}\right)} \]
  5. Taylor expanded in u around 0 25.5%

    \[\leadsto \color{blue}{-4 \cdot \frac{s \cdot \left(u \cdot \left(-0.25 \cdot \frac{\pi}{s} - 0.25 \cdot \frac{\pi}{s}\right)\right)}{1 + \frac{\pi}{s}} + -1 \cdot \left(s \cdot \log \left(1 + \frac{\pi}{s}\right)\right)} \]
  6. Step-by-step derivation
    1. add-sqr-sqrt25.5%

      \[\leadsto -4 \cdot \frac{s \cdot \left(u \cdot \left(-0.25 \cdot \frac{\pi}{s} - 0.25 \cdot \frac{\pi}{s}\right)\right)}{1 + \frac{\pi}{\color{blue}{\sqrt{s} \cdot \sqrt{s}}}} + -1 \cdot \left(s \cdot \log \left(1 + \frac{\pi}{s}\right)\right) \]
    2. sqrt-unprod25.5%

      \[\leadsto -4 \cdot \frac{s \cdot \left(u \cdot \left(-0.25 \cdot \frac{\pi}{s} - 0.25 \cdot \frac{\pi}{s}\right)\right)}{1 + \frac{\pi}{\color{blue}{\sqrt{s \cdot s}}}} + -1 \cdot \left(s \cdot \log \left(1 + \frac{\pi}{s}\right)\right) \]
    3. sqr-neg25.5%

      \[\leadsto -4 \cdot \frac{s \cdot \left(u \cdot \left(-0.25 \cdot \frac{\pi}{s} - 0.25 \cdot \frac{\pi}{s}\right)\right)}{1 + \frac{\pi}{\sqrt{\color{blue}{\left(-s\right) \cdot \left(-s\right)}}}} + -1 \cdot \left(s \cdot \log \left(1 + \frac{\pi}{s}\right)\right) \]
    4. sqrt-unprod-0.0%

      \[\leadsto -4 \cdot \frac{s \cdot \left(u \cdot \left(-0.25 \cdot \frac{\pi}{s} - 0.25 \cdot \frac{\pi}{s}\right)\right)}{1 + \frac{\pi}{\color{blue}{\sqrt{-s} \cdot \sqrt{-s}}}} + -1 \cdot \left(s \cdot \log \left(1 + \frac{\pi}{s}\right)\right) \]
    5. add-sqr-sqrt25.5%

      \[\leadsto -4 \cdot \frac{s \cdot \left(u \cdot \left(-0.25 \cdot \frac{\pi}{s} - 0.25 \cdot \frac{\pi}{s}\right)\right)}{1 + \frac{\pi}{\color{blue}{-s}}} + -1 \cdot \left(s \cdot \log \left(1 + \frac{\pi}{s}\right)\right) \]
    6. distribute-frac-neg225.5%

      \[\leadsto -4 \cdot \frac{s \cdot \left(u \cdot \left(-0.25 \cdot \frac{\pi}{s} - 0.25 \cdot \frac{\pi}{s}\right)\right)}{1 + \color{blue}{\left(-\frac{\pi}{s}\right)}} + -1 \cdot \left(s \cdot \log \left(1 + \frac{\pi}{s}\right)\right) \]
  7. Applied egg-rr25.5%

    \[\leadsto -4 \cdot \frac{s \cdot \left(u \cdot \left(-0.25 \cdot \frac{\pi}{s} - 0.25 \cdot \frac{\pi}{s}\right)\right)}{1 + \color{blue}{\left(-\frac{\pi}{s}\right)}} + -1 \cdot \left(s \cdot \log \left(1 + \frac{\pi}{s}\right)\right) \]
  8. Final simplification25.5%

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

Alternative 7: 25.0% accurate, 4.1× speedup?

\[\begin{array}{l} \\ s \cdot \left(-\mathsf{log1p}\left(\frac{\pi}{s}\right)\right) \end{array} \]
(FPCore (u s) :precision binary32 (* s (- (log1p (/ PI s)))))
float code(float u, float s) {
	return s * -log1pf((((float) M_PI) / s));
}
function code(u, s)
	return Float32(s * Float32(-log1p(Float32(Float32(pi) / s))))
end
\begin{array}{l}

\\
s \cdot \left(-\mathsf{log1p}\left(\frac{\pi}{s}\right)\right)
\end{array}
Derivation
  1. Initial program 98.6%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.6%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in s around -inf 25.4%

    \[\leadsto \left(-s\right) \cdot \log \color{blue}{\left(1 + 4 \cdot \frac{-0.25 \cdot \left(u \cdot \pi\right) - \left(-0.25 \cdot \pi + 0.25 \cdot \left(u \cdot \pi\right)\right)}{s}\right)} \]
  5. Taylor expanded in u around 0 25.5%

    \[\leadsto \color{blue}{-1 \cdot \left(s \cdot \log \left(1 + \frac{\pi}{s}\right)\right)} \]
  6. Step-by-step derivation
    1. log1p-define25.5%

      \[\leadsto -1 \cdot \left(s \cdot \color{blue}{\mathsf{log1p}\left(\frac{\pi}{s}\right)}\right) \]
    2. associate-*r*25.5%

      \[\leadsto \color{blue}{\left(-1 \cdot s\right) \cdot \mathsf{log1p}\left(\frac{\pi}{s}\right)} \]
    3. neg-mul-125.5%

      \[\leadsto \color{blue}{\left(-s\right)} \cdot \mathsf{log1p}\left(\frac{\pi}{s}\right) \]
  7. Simplified25.5%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \mathsf{log1p}\left(\frac{\pi}{s}\right)} \]
  8. Final simplification25.5%

    \[\leadsto s \cdot \left(-\mathsf{log1p}\left(\frac{\pi}{s}\right)\right) \]
  9. Add Preprocessing

Alternative 8: 11.7% accurate, 48.1× speedup?

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

\\
u \cdot \left(\pi \cdot 2 - \frac{\pi}{u}\right)
\end{array}
Derivation
  1. Initial program 98.6%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.6%

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

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

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

      \[\leadsto \left(-s\right) \cdot \left(-4 \cdot \frac{\color{blue}{\left(0.25 \cdot \left(u \cdot \pi\right) - -0.25 \cdot \left(u \cdot \pi\right)\right) + \left(-0.25\right) \cdot \pi}}{s}\right) \]
    3. distribute-rgt-out--11.7%

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

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

      \[\leadsto \left(-s\right) \cdot \left(-4 \cdot \frac{\left(\pi \cdot u\right) \cdot \color{blue}{0.5} + \left(-0.25\right) \cdot \pi}{s}\right) \]
    6. metadata-eval11.7%

      \[\leadsto \left(-s\right) \cdot \left(-4 \cdot \frac{\left(\pi \cdot u\right) \cdot 0.5 + \color{blue}{-0.25} \cdot \pi}{s}\right) \]
    7. *-commutative11.7%

      \[\leadsto \left(-s\right) \cdot \left(-4 \cdot \frac{\left(\pi \cdot u\right) \cdot 0.5 + \color{blue}{\pi \cdot -0.25}}{s}\right) \]
  6. Simplified11.7%

    \[\leadsto \left(-s\right) \cdot \color{blue}{\left(-4 \cdot \frac{\left(\pi \cdot u\right) \cdot 0.5 + \pi \cdot -0.25}{s}\right)} \]
  7. Taylor expanded in u around inf 11.7%

    \[\leadsto \color{blue}{u \cdot \left(-1 \cdot \frac{\pi}{u} + 2 \cdot \pi\right)} \]
  8. Step-by-step derivation
    1. +-commutative11.7%

      \[\leadsto u \cdot \color{blue}{\left(2 \cdot \pi + -1 \cdot \frac{\pi}{u}\right)} \]
    2. mul-1-neg11.7%

      \[\leadsto u \cdot \left(2 \cdot \pi + \color{blue}{\left(-\frac{\pi}{u}\right)}\right) \]
    3. unsub-neg11.7%

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

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

    \[\leadsto \color{blue}{u \cdot \left(\pi \cdot 2 - \frac{\pi}{u}\right)} \]
  10. Add Preprocessing

Alternative 9: 11.7% accurate, 61.9× speedup?

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

\\
2 \cdot \left(u \cdot \pi\right) - \pi
\end{array}
Derivation
  1. Initial program 98.6%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.6%

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

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

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

      \[\leadsto \left(-s\right) \cdot \left(-4 \cdot \frac{\color{blue}{\left(0.25 \cdot \left(u \cdot \pi\right) - -0.25 \cdot \left(u \cdot \pi\right)\right) + \left(-0.25\right) \cdot \pi}}{s}\right) \]
    3. distribute-rgt-out--11.7%

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

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

      \[\leadsto \left(-s\right) \cdot \left(-4 \cdot \frac{\left(\pi \cdot u\right) \cdot \color{blue}{0.5} + \left(-0.25\right) \cdot \pi}{s}\right) \]
    6. metadata-eval11.7%

      \[\leadsto \left(-s\right) \cdot \left(-4 \cdot \frac{\left(\pi \cdot u\right) \cdot 0.5 + \color{blue}{-0.25} \cdot \pi}{s}\right) \]
    7. *-commutative11.7%

      \[\leadsto \left(-s\right) \cdot \left(-4 \cdot \frac{\left(\pi \cdot u\right) \cdot 0.5 + \color{blue}{\pi \cdot -0.25}}{s}\right) \]
  6. Simplified11.7%

    \[\leadsto \left(-s\right) \cdot \color{blue}{\left(-4 \cdot \frac{\left(\pi \cdot u\right) \cdot 0.5 + \pi \cdot -0.25}{s}\right)} \]
  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. unsub-neg11.7%

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

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

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

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

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

Alternative 10: 11.5% accurate, 72.2× speedup?

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

\\
\frac{s \cdot \left(-\pi\right)}{s}
\end{array}
Derivation
  1. Initial program 98.6%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.6%

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

    \[\leadsto \left(-s\right) \cdot \color{blue}{\frac{\pi}{s}} \]
  5. Step-by-step derivation
    1. associate-*r/11.6%

      \[\leadsto \color{blue}{\frac{\left(-s\right) \cdot \pi}{s}} \]
  6. Applied egg-rr11.6%

    \[\leadsto \color{blue}{\frac{\left(-s\right) \cdot \pi}{s}} \]
  7. Final simplification11.6%

    \[\leadsto \frac{s \cdot \left(-\pi\right)}{s} \]
  8. Add Preprocessing

Alternative 11: 11.5% 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 98.6%

    \[\left(-s\right) \cdot \log \left(\frac{1}{u \cdot \left(\frac{1}{1 + e^{\frac{-\pi}{s}}} - \frac{1}{1 + e^{\frac{\pi}{s}}}\right) + \frac{1}{1 + e^{\frac{\pi}{s}}}} - 1\right) \]
  2. Simplified98.6%

    \[\leadsto \color{blue}{\left(-s\right) \cdot \log \left(\frac{1}{\frac{u}{1 + e^{\frac{\pi}{-s}}} + \frac{1 - u}{1 + e^{\frac{\pi}{s}}}} + -1\right)} \]
  3. Add Preprocessing
  4. Taylor expanded in u around 0 11.6%

    \[\leadsto \color{blue}{-1 \cdot \pi} \]
  5. Step-by-step derivation
    1. neg-mul-111.6%

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

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

Reproduce

?
herbie shell --seed 2024132 
(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))))