Harley's example

Percentage Accurate: 90.5% → 99.5%
Time: 53.2s
Alternatives: 9
Speedup: 896.0×

Specification

?
\[0 < c\_p \land 0 < c\_n\]
\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{1}{1 + e^{-t}}\\ t_2 := \frac{1}{1 + e^{-s}}\\ \frac{{t\_2}^{c\_p} \cdot {\left(1 - t\_2\right)}^{c\_n}}{{t\_1}^{c\_p} \cdot {\left(1 - t\_1\right)}^{c\_n}} \end{array} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (let* ((t_1 (/ 1.0 (+ 1.0 (exp (- t))))) (t_2 (/ 1.0 (+ 1.0 (exp (- s))))))
   (/
    (* (pow t_2 c_p) (pow (- 1.0 t_2) c_n))
    (* (pow t_1 c_p) (pow (- 1.0 t_1) c_n)))))
double code(double c_p, double c_n, double t, double s) {
	double t_1 = 1.0 / (1.0 + exp(-t));
	double t_2 = 1.0 / (1.0 + exp(-s));
	return (pow(t_2, c_p) * pow((1.0 - t_2), c_n)) / (pow(t_1, c_p) * pow((1.0 - t_1), c_n));
}
real(8) function code(c_p, c_n, t, s)
    real(8), intent (in) :: c_p
    real(8), intent (in) :: c_n
    real(8), intent (in) :: t
    real(8), intent (in) :: s
    real(8) :: t_1
    real(8) :: t_2
    t_1 = 1.0d0 / (1.0d0 + exp(-t))
    t_2 = 1.0d0 / (1.0d0 + exp(-s))
    code = ((t_2 ** c_p) * ((1.0d0 - t_2) ** c_n)) / ((t_1 ** c_p) * ((1.0d0 - t_1) ** c_n))
end function
public static double code(double c_p, double c_n, double t, double s) {
	double t_1 = 1.0 / (1.0 + Math.exp(-t));
	double t_2 = 1.0 / (1.0 + Math.exp(-s));
	return (Math.pow(t_2, c_p) * Math.pow((1.0 - t_2), c_n)) / (Math.pow(t_1, c_p) * Math.pow((1.0 - t_1), c_n));
}
def code(c_p, c_n, t, s):
	t_1 = 1.0 / (1.0 + math.exp(-t))
	t_2 = 1.0 / (1.0 + math.exp(-s))
	return (math.pow(t_2, c_p) * math.pow((1.0 - t_2), c_n)) / (math.pow(t_1, c_p) * math.pow((1.0 - t_1), c_n))
function code(c_p, c_n, t, s)
	t_1 = Float64(1.0 / Float64(1.0 + exp(Float64(-t))))
	t_2 = Float64(1.0 / Float64(1.0 + exp(Float64(-s))))
	return Float64(Float64((t_2 ^ c_p) * (Float64(1.0 - t_2) ^ c_n)) / Float64((t_1 ^ c_p) * (Float64(1.0 - t_1) ^ c_n)))
end
function tmp = code(c_p, c_n, t, s)
	t_1 = 1.0 / (1.0 + exp(-t));
	t_2 = 1.0 / (1.0 + exp(-s));
	tmp = ((t_2 ^ c_p) * ((1.0 - t_2) ^ c_n)) / ((t_1 ^ c_p) * ((1.0 - t_1) ^ c_n));
end
code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[(1.0 / N[(1.0 + N[Exp[(-t)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(1.0 / N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[Power[t$95$2, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$2), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision] / N[(N[Power[t$95$1, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$1), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{1}{1 + e^{-t}}\\
t_2 := \frac{1}{1 + e^{-s}}\\
\frac{{t\_2}^{c\_p} \cdot {\left(1 - t\_2\right)}^{c\_n}}{{t\_1}^{c\_p} \cdot {\left(1 - t\_1\right)}^{c\_n}}
\end{array}
\end{array}

Sampling outcomes in binary64 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: 90.5% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := \frac{1}{1 + e^{-t}}\\ t_2 := \frac{1}{1 + e^{-s}}\\ \frac{{t\_2}^{c\_p} \cdot {\left(1 - t\_2\right)}^{c\_n}}{{t\_1}^{c\_p} \cdot {\left(1 - t\_1\right)}^{c\_n}} \end{array} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (let* ((t_1 (/ 1.0 (+ 1.0 (exp (- t))))) (t_2 (/ 1.0 (+ 1.0 (exp (- s))))))
   (/
    (* (pow t_2 c_p) (pow (- 1.0 t_2) c_n))
    (* (pow t_1 c_p) (pow (- 1.0 t_1) c_n)))))
double code(double c_p, double c_n, double t, double s) {
	double t_1 = 1.0 / (1.0 + exp(-t));
	double t_2 = 1.0 / (1.0 + exp(-s));
	return (pow(t_2, c_p) * pow((1.0 - t_2), c_n)) / (pow(t_1, c_p) * pow((1.0 - t_1), c_n));
}
real(8) function code(c_p, c_n, t, s)
    real(8), intent (in) :: c_p
    real(8), intent (in) :: c_n
    real(8), intent (in) :: t
    real(8), intent (in) :: s
    real(8) :: t_1
    real(8) :: t_2
    t_1 = 1.0d0 / (1.0d0 + exp(-t))
    t_2 = 1.0d0 / (1.0d0 + exp(-s))
    code = ((t_2 ** c_p) * ((1.0d0 - t_2) ** c_n)) / ((t_1 ** c_p) * ((1.0d0 - t_1) ** c_n))
end function
public static double code(double c_p, double c_n, double t, double s) {
	double t_1 = 1.0 / (1.0 + Math.exp(-t));
	double t_2 = 1.0 / (1.0 + Math.exp(-s));
	return (Math.pow(t_2, c_p) * Math.pow((1.0 - t_2), c_n)) / (Math.pow(t_1, c_p) * Math.pow((1.0 - t_1), c_n));
}
def code(c_p, c_n, t, s):
	t_1 = 1.0 / (1.0 + math.exp(-t))
	t_2 = 1.0 / (1.0 + math.exp(-s))
	return (math.pow(t_2, c_p) * math.pow((1.0 - t_2), c_n)) / (math.pow(t_1, c_p) * math.pow((1.0 - t_1), c_n))
function code(c_p, c_n, t, s)
	t_1 = Float64(1.0 / Float64(1.0 + exp(Float64(-t))))
	t_2 = Float64(1.0 / Float64(1.0 + exp(Float64(-s))))
	return Float64(Float64((t_2 ^ c_p) * (Float64(1.0 - t_2) ^ c_n)) / Float64((t_1 ^ c_p) * (Float64(1.0 - t_1) ^ c_n)))
end
function tmp = code(c_p, c_n, t, s)
	t_1 = 1.0 / (1.0 + exp(-t));
	t_2 = 1.0 / (1.0 + exp(-s));
	tmp = ((t_2 ^ c_p) * ((1.0 - t_2) ^ c_n)) / ((t_1 ^ c_p) * ((1.0 - t_1) ^ c_n));
end
code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[(1.0 / N[(1.0 + N[Exp[(-t)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(1.0 / N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, N[(N[(N[Power[t$95$2, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$2), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision] / N[(N[Power[t$95$1, c$95$p], $MachinePrecision] * N[Power[N[(1.0 - t$95$1), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := \frac{1}{1 + e^{-t}}\\
t_2 := \frac{1}{1 + e^{-s}}\\
\frac{{t\_2}^{c\_p} \cdot {\left(1 - t\_2\right)}^{c\_n}}{{t\_1}^{c\_p} \cdot {\left(1 - t\_1\right)}^{c\_n}}
\end{array}
\end{array}

Alternative 1: 99.5% accurate, 6.3× speedup?

\[\begin{array}{l} \\ e^{\mathsf{fma}\left(s, \mathsf{fma}\left(-0.5, c\_n - c\_p, -0.125 \cdot \left(s \cdot \left(c\_n + c\_p\right)\right)\right), -0.5 \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)\right)} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (exp
  (fma
   s
   (fma -0.5 (- c_n c_p) (* -0.125 (* s (+ c_n c_p))))
   (* -0.5 (* (- c_p c_n) t)))))
double code(double c_p, double c_n, double t, double s) {
	return exp(fma(s, fma(-0.5, (c_n - c_p), (-0.125 * (s * (c_n + c_p)))), (-0.5 * ((c_p - c_n) * t))));
}
function code(c_p, c_n, t, s)
	return exp(fma(s, fma(-0.5, Float64(c_n - c_p), Float64(-0.125 * Float64(s * Float64(c_n + c_p)))), Float64(-0.5 * Float64(Float64(c_p - c_n) * t))))
end
code[c$95$p_, c$95$n_, t_, s_] := N[Exp[N[(s * N[(-0.5 * N[(c$95$n - c$95$p), $MachinePrecision] + N[(-0.125 * N[(s * N[(c$95$n + c$95$p), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + N[(-0.5 * N[(N[(c$95$p - c$95$n), $MachinePrecision] * t), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
e^{\mathsf{fma}\left(s, \mathsf{fma}\left(-0.5, c\_n - c\_p, -0.125 \cdot \left(s \cdot \left(c\_n + c\_p\right)\right)\right), -0.5 \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)\right)}
\end{array}
Derivation
  1. Initial program 89.6%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Add Preprocessing
  3. Applied rewrites94.1%

    \[\leadsto \color{blue}{e^{\mathsf{fma}\left(c\_p, \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right), c\_n \cdot \left(\mathsf{log1p}\left(\frac{1}{-1 - e^{-s}}\right) - \mathsf{log1p}\left(\frac{-1}{1 + e^{-t}}\right)\right)\right)}} \]
  4. Taylor expanded in t around 0

    \[\leadsto e^{\color{blue}{c\_n \cdot \left(\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}\right) + \left(c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
  5. Step-by-step derivation
    1. lower-fma.f64N/A

      \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
    2. lower--.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    3. sub-negN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \log \color{blue}{\left(1 + \left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    4. lower-log1p.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\mathsf{log1p}\left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    5. distribute-neg-fracN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{\mathsf{neg}\left(1\right)}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    6. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{\color{blue}{-1}}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    7. lower-/.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    8. lower-+.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{\color{blue}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    9. lower-exp.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    10. lower-neg.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    11. lower-log.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \color{blue}{\log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
  6. Applied rewrites98.1%

    \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{-s}}\right) - \log 0.5, \mathsf{fma}\left(c\_p, \log 2 - \mathsf{log1p}\left(e^{-s}\right), t \cdot \mathsf{fma}\left(c\_n, 0.5, c\_p \cdot -0.5\right)\right)\right)}} \]
  7. Taylor expanded in s around 0

    \[\leadsto e^{\color{blue}{s \cdot \left(\frac{-1}{2} \cdot c\_n + \left(\frac{1}{2} \cdot c\_p + s \cdot \left(\frac{-1}{8} \cdot c\_n + \frac{-1}{8} \cdot c\_p\right)\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)}} \]
  8. Step-by-step derivation
    1. lower-fma.f64N/A

      \[\leadsto e^{\color{blue}{\mathsf{fma}\left(s, \frac{-1}{2} \cdot c\_n + \left(\frac{1}{2} \cdot c\_p + s \cdot \left(\frac{-1}{8} \cdot c\_n + \frac{-1}{8} \cdot c\_p\right)\right), t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
  9. Applied rewrites99.5%

    \[\leadsto e^{\color{blue}{\mathsf{fma}\left(s, \mathsf{fma}\left(-0.5, c\_n - c\_p, -0.125 \cdot \left(\left(c\_p + c\_n\right) \cdot s\right)\right), -0.5 \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)\right)}} \]
  10. Final simplification99.5%

    \[\leadsto e^{\mathsf{fma}\left(s, \mathsf{fma}\left(-0.5, c\_n - c\_p, -0.125 \cdot \left(s \cdot \left(c\_n + c\_p\right)\right)\right), -0.5 \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)\right)} \]
  11. Add Preprocessing

Alternative 2: 99.4% accurate, 7.0× speedup?

\[\begin{array}{l} \\ e^{\mathsf{fma}\left(-0.5, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-0.5 \cdot \left(c\_n - c\_p\right)\right)\right)} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (exp (fma -0.5 (* (- c_p c_n) t) (* s (* -0.5 (- c_n c_p))))))
double code(double c_p, double c_n, double t, double s) {
	return exp(fma(-0.5, ((c_p - c_n) * t), (s * (-0.5 * (c_n - c_p)))));
}
function code(c_p, c_n, t, s)
	return exp(fma(-0.5, Float64(Float64(c_p - c_n) * t), Float64(s * Float64(-0.5 * Float64(c_n - c_p)))))
end
code[c$95$p_, c$95$n_, t_, s_] := N[Exp[N[(-0.5 * N[(N[(c$95$p - c$95$n), $MachinePrecision] * t), $MachinePrecision] + N[(s * N[(-0.5 * N[(c$95$n - c$95$p), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
e^{\mathsf{fma}\left(-0.5, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-0.5 \cdot \left(c\_n - c\_p\right)\right)\right)}
\end{array}
Derivation
  1. Initial program 89.6%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Add Preprocessing
  3. Applied rewrites94.1%

    \[\leadsto \color{blue}{e^{\mathsf{fma}\left(c\_p, \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right), c\_n \cdot \left(\mathsf{log1p}\left(\frac{1}{-1 - e^{-s}}\right) - \mathsf{log1p}\left(\frac{-1}{1 + e^{-t}}\right)\right)\right)}} \]
  4. Taylor expanded in t around 0

    \[\leadsto e^{\color{blue}{c\_n \cdot \left(\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}\right) + \left(c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
  5. Step-by-step derivation
    1. lower-fma.f64N/A

      \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
    2. lower--.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    3. sub-negN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \log \color{blue}{\left(1 + \left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    4. lower-log1p.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\mathsf{log1p}\left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    5. distribute-neg-fracN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{\mathsf{neg}\left(1\right)}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    6. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{\color{blue}{-1}}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    7. lower-/.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    8. lower-+.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{\color{blue}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    9. lower-exp.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    10. lower-neg.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    11. lower-log.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \color{blue}{\log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
  6. Applied rewrites98.1%

    \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{-s}}\right) - \log 0.5, \mathsf{fma}\left(c\_p, \log 2 - \mathsf{log1p}\left(e^{-s}\right), t \cdot \mathsf{fma}\left(c\_n, 0.5, c\_p \cdot -0.5\right)\right)\right)}} \]
  7. Taylor expanded in s around 0

    \[\leadsto e^{\color{blue}{s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)}} \]
  8. Step-by-step derivation
    1. +-commutativeN/A

      \[\leadsto e^{\color{blue}{t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right) + s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)}} \]
    2. *-commutativeN/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right) \cdot t} + s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)} \]
    3. metadata-evalN/A

      \[\leadsto e^{\left(\frac{-1}{2} \cdot c\_p + \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{2}\right)\right)} \cdot c\_n\right) \cdot t + s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)} \]
    4. cancel-sign-sub-invN/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot c\_p - \frac{-1}{2} \cdot c\_n\right)} \cdot t + s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)} \]
    5. distribute-lft-out--N/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot \left(c\_p - c\_n\right)\right)} \cdot t + s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)} \]
    6. associate-*l*N/A

      \[\leadsto e^{\color{blue}{\frac{-1}{2} \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)} + s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)} \]
    7. lower-fma.f64N/A

      \[\leadsto e^{\color{blue}{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)\right)}} \]
    8. lower-*.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \color{blue}{\left(c\_p - c\_n\right) \cdot t}, s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)\right)} \]
    9. lower--.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \color{blue}{\left(c\_p - c\_n\right)} \cdot t, s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)\right)} \]
    10. lower-*.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, \color{blue}{s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)}\right)} \]
    11. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(\color{blue}{\left(-1 \cdot \frac{1}{2}\right)} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)\right)} \]
    12. associate-*r*N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(\color{blue}{-1 \cdot \left(\frac{1}{2} \cdot c\_n\right)} + \frac{1}{2} \cdot c\_p\right)\right)} \]
    13. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-1 \cdot \left(\frac{1}{2} \cdot c\_n\right) + \color{blue}{\left(-1 \cdot \frac{-1}{2}\right)} \cdot c\_p\right)\right)} \]
    14. associate-*r*N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-1 \cdot \left(\frac{1}{2} \cdot c\_n\right) + \color{blue}{-1 \cdot \left(\frac{-1}{2} \cdot c\_p\right)}\right)\right)} \]
    15. distribute-lft-inN/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \color{blue}{\left(-1 \cdot \left(\frac{1}{2} \cdot c\_n + \frac{-1}{2} \cdot c\_p\right)\right)}\right)} \]
    16. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-1 \cdot \left(\frac{1}{2} \cdot c\_n + \color{blue}{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)} \cdot c\_p\right)\right)\right)} \]
    17. cancel-sign-sub-invN/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-1 \cdot \color{blue}{\left(\frac{1}{2} \cdot c\_n - \frac{1}{2} \cdot c\_p\right)}\right)\right)} \]
    18. distribute-lft-out--N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-1 \cdot \color{blue}{\left(\frac{1}{2} \cdot \left(c\_n - c\_p\right)\right)}\right)\right)} \]
    19. associate-*r*N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \color{blue}{\left(\left(-1 \cdot \frac{1}{2}\right) \cdot \left(c\_n - c\_p\right)\right)}\right)} \]
    20. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(\color{blue}{\frac{-1}{2}} \cdot \left(c\_n - c\_p\right)\right)\right)} \]
    21. lower-*.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \color{blue}{\left(\frac{-1}{2} \cdot \left(c\_n - c\_p\right)\right)}\right)} \]
    22. lower--.f6499.4

      \[\leadsto e^{\mathsf{fma}\left(-0.5, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-0.5 \cdot \color{blue}{\left(c\_n - c\_p\right)}\right)\right)} \]
  9. Applied rewrites99.4%

    \[\leadsto e^{\color{blue}{\mathsf{fma}\left(-0.5, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-0.5 \cdot \left(c\_n - c\_p\right)\right)\right)}} \]
  10. Add Preprocessing

Alternative 3: 98.7% accurate, 7.3× speedup?

\[\begin{array}{l} \\ e^{c\_n \cdot \mathsf{fma}\left(t, 0.5, s \cdot \mathsf{fma}\left(s, -0.125, -0.5\right)\right)} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (exp (* c_n (fma t 0.5 (* s (fma s -0.125 -0.5))))))
double code(double c_p, double c_n, double t, double s) {
	return exp((c_n * fma(t, 0.5, (s * fma(s, -0.125, -0.5)))));
}
function code(c_p, c_n, t, s)
	return exp(Float64(c_n * fma(t, 0.5, Float64(s * fma(s, -0.125, -0.5)))))
end
code[c$95$p_, c$95$n_, t_, s_] := N[Exp[N[(c$95$n * N[(t * 0.5 + N[(s * N[(s * -0.125 + -0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
e^{c\_n \cdot \mathsf{fma}\left(t, 0.5, s \cdot \mathsf{fma}\left(s, -0.125, -0.5\right)\right)}
\end{array}
Derivation
  1. Initial program 89.6%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Add Preprocessing
  3. Applied rewrites94.1%

    \[\leadsto \color{blue}{e^{\mathsf{fma}\left(c\_p, \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right), c\_n \cdot \left(\mathsf{log1p}\left(\frac{1}{-1 - e^{-s}}\right) - \mathsf{log1p}\left(\frac{-1}{1 + e^{-t}}\right)\right)\right)}} \]
  4. Taylor expanded in t around 0

    \[\leadsto e^{\color{blue}{c\_n \cdot \left(\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}\right) + \left(c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
  5. Step-by-step derivation
    1. lower-fma.f64N/A

      \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
    2. lower--.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    3. sub-negN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \log \color{blue}{\left(1 + \left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    4. lower-log1p.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\mathsf{log1p}\left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    5. distribute-neg-fracN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{\mathsf{neg}\left(1\right)}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    6. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{\color{blue}{-1}}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    7. lower-/.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    8. lower-+.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{\color{blue}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    9. lower-exp.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    10. lower-neg.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    11. lower-log.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \color{blue}{\log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
  6. Applied rewrites98.1%

    \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{-s}}\right) - \log 0.5, \mathsf{fma}\left(c\_p, \log 2 - \mathsf{log1p}\left(e^{-s}\right), t \cdot \mathsf{fma}\left(c\_n, 0.5, c\_p \cdot -0.5\right)\right)\right)}} \]
  7. Taylor expanded in s around 0

    \[\leadsto e^{\color{blue}{s \cdot \left(\frac{-1}{2} \cdot c\_n + \left(\frac{1}{2} \cdot c\_p + s \cdot \left(\frac{-1}{8} \cdot c\_n + \frac{-1}{8} \cdot c\_p\right)\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)}} \]
  8. Step-by-step derivation
    1. lower-fma.f64N/A

      \[\leadsto e^{\color{blue}{\mathsf{fma}\left(s, \frac{-1}{2} \cdot c\_n + \left(\frac{1}{2} \cdot c\_p + s \cdot \left(\frac{-1}{8} \cdot c\_n + \frac{-1}{8} \cdot c\_p\right)\right), t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
  9. Applied rewrites99.5%

    \[\leadsto e^{\color{blue}{\mathsf{fma}\left(s, \mathsf{fma}\left(-0.5, c\_n - c\_p, -0.125 \cdot \left(\left(c\_p + c\_n\right) \cdot s\right)\right), -0.5 \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)\right)}} \]
  10. Taylor expanded in c_n around inf

    \[\leadsto e^{\color{blue}{c\_n \cdot \left(\frac{1}{2} \cdot t + s \cdot \left(\frac{-1}{8} \cdot s - \frac{1}{2}\right)\right)}} \]
  11. Step-by-step derivation
    1. lower-*.f64N/A

      \[\leadsto e^{\color{blue}{c\_n \cdot \left(\frac{1}{2} \cdot t + s \cdot \left(\frac{-1}{8} \cdot s - \frac{1}{2}\right)\right)}} \]
    2. *-commutativeN/A

      \[\leadsto e^{c\_n \cdot \left(\color{blue}{t \cdot \frac{1}{2}} + s \cdot \left(\frac{-1}{8} \cdot s - \frac{1}{2}\right)\right)} \]
    3. lower-fma.f64N/A

      \[\leadsto e^{c\_n \cdot \color{blue}{\mathsf{fma}\left(t, \frac{1}{2}, s \cdot \left(\frac{-1}{8} \cdot s - \frac{1}{2}\right)\right)}} \]
    4. lower-*.f64N/A

      \[\leadsto e^{c\_n \cdot \mathsf{fma}\left(t, \frac{1}{2}, \color{blue}{s \cdot \left(\frac{-1}{8} \cdot s - \frac{1}{2}\right)}\right)} \]
    5. sub-negN/A

      \[\leadsto e^{c\_n \cdot \mathsf{fma}\left(t, \frac{1}{2}, s \cdot \color{blue}{\left(\frac{-1}{8} \cdot s + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right)}\right)} \]
    6. *-commutativeN/A

      \[\leadsto e^{c\_n \cdot \mathsf{fma}\left(t, \frac{1}{2}, s \cdot \left(\color{blue}{s \cdot \frac{-1}{8}} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)\right)\right)} \]
    7. metadata-evalN/A

      \[\leadsto e^{c\_n \cdot \mathsf{fma}\left(t, \frac{1}{2}, s \cdot \left(s \cdot \frac{-1}{8} + \color{blue}{\frac{-1}{2}}\right)\right)} \]
    8. lower-fma.f6498.6

      \[\leadsto e^{c\_n \cdot \mathsf{fma}\left(t, 0.5, s \cdot \color{blue}{\mathsf{fma}\left(s, -0.125, -0.5\right)}\right)} \]
  12. Applied rewrites98.6%

    \[\leadsto e^{\color{blue}{c\_n \cdot \mathsf{fma}\left(t, 0.5, s \cdot \mathsf{fma}\left(s, -0.125, -0.5\right)\right)}} \]
  13. Add Preprocessing

Alternative 4: 98.4% accurate, 7.9× speedup?

\[\begin{array}{l} \\ e^{-0.5 \cdot \left(s \cdot \left(c\_n - c\_p\right)\right)} \end{array} \]
(FPCore (c_p c_n t s) :precision binary64 (exp (* -0.5 (* s (- c_n c_p)))))
double code(double c_p, double c_n, double t, double s) {
	return exp((-0.5 * (s * (c_n - c_p))));
}
real(8) function code(c_p, c_n, t, s)
    real(8), intent (in) :: c_p
    real(8), intent (in) :: c_n
    real(8), intent (in) :: t
    real(8), intent (in) :: s
    code = exp(((-0.5d0) * (s * (c_n - c_p))))
end function
public static double code(double c_p, double c_n, double t, double s) {
	return Math.exp((-0.5 * (s * (c_n - c_p))));
}
def code(c_p, c_n, t, s):
	return math.exp((-0.5 * (s * (c_n - c_p))))
function code(c_p, c_n, t, s)
	return exp(Float64(-0.5 * Float64(s * Float64(c_n - c_p))))
end
function tmp = code(c_p, c_n, t, s)
	tmp = exp((-0.5 * (s * (c_n - c_p))));
end
code[c$95$p_, c$95$n_, t_, s_] := N[Exp[N[(-0.5 * N[(s * N[(c$95$n - c$95$p), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
e^{-0.5 \cdot \left(s \cdot \left(c\_n - c\_p\right)\right)}
\end{array}
Derivation
  1. Initial program 89.6%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Add Preprocessing
  3. Applied rewrites94.1%

    \[\leadsto \color{blue}{e^{\mathsf{fma}\left(c\_p, \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right), c\_n \cdot \left(\mathsf{log1p}\left(\frac{1}{-1 - e^{-s}}\right) - \mathsf{log1p}\left(\frac{-1}{1 + e^{-t}}\right)\right)\right)}} \]
  4. Taylor expanded in t around 0

    \[\leadsto e^{\color{blue}{c\_n \cdot \left(\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}\right) + \left(c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
  5. Step-by-step derivation
    1. lower-fma.f64N/A

      \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
    2. lower--.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    3. sub-negN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \log \color{blue}{\left(1 + \left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    4. lower-log1p.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\mathsf{log1p}\left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    5. distribute-neg-fracN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{\mathsf{neg}\left(1\right)}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    6. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{\color{blue}{-1}}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    7. lower-/.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    8. lower-+.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{\color{blue}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    9. lower-exp.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    10. lower-neg.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    11. lower-log.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \color{blue}{\log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
  6. Applied rewrites98.1%

    \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{-s}}\right) - \log 0.5, \mathsf{fma}\left(c\_p, \log 2 - \mathsf{log1p}\left(e^{-s}\right), t \cdot \mathsf{fma}\left(c\_n, 0.5, c\_p \cdot -0.5\right)\right)\right)}} \]
  7. Taylor expanded in s around 0

    \[\leadsto e^{\color{blue}{s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)}} \]
  8. Step-by-step derivation
    1. +-commutativeN/A

      \[\leadsto e^{\color{blue}{t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right) + s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)}} \]
    2. *-commutativeN/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right) \cdot t} + s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)} \]
    3. metadata-evalN/A

      \[\leadsto e^{\left(\frac{-1}{2} \cdot c\_p + \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{2}\right)\right)} \cdot c\_n\right) \cdot t + s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)} \]
    4. cancel-sign-sub-invN/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot c\_p - \frac{-1}{2} \cdot c\_n\right)} \cdot t + s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)} \]
    5. distribute-lft-out--N/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot \left(c\_p - c\_n\right)\right)} \cdot t + s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)} \]
    6. associate-*l*N/A

      \[\leadsto e^{\color{blue}{\frac{-1}{2} \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)} + s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)} \]
    7. lower-fma.f64N/A

      \[\leadsto e^{\color{blue}{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)\right)}} \]
    8. lower-*.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \color{blue}{\left(c\_p - c\_n\right) \cdot t}, s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)\right)} \]
    9. lower--.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \color{blue}{\left(c\_p - c\_n\right)} \cdot t, s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)\right)} \]
    10. lower-*.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, \color{blue}{s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)}\right)} \]
    11. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(\color{blue}{\left(-1 \cdot \frac{1}{2}\right)} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)\right)} \]
    12. associate-*r*N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(\color{blue}{-1 \cdot \left(\frac{1}{2} \cdot c\_n\right)} + \frac{1}{2} \cdot c\_p\right)\right)} \]
    13. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-1 \cdot \left(\frac{1}{2} \cdot c\_n\right) + \color{blue}{\left(-1 \cdot \frac{-1}{2}\right)} \cdot c\_p\right)\right)} \]
    14. associate-*r*N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-1 \cdot \left(\frac{1}{2} \cdot c\_n\right) + \color{blue}{-1 \cdot \left(\frac{-1}{2} \cdot c\_p\right)}\right)\right)} \]
    15. distribute-lft-inN/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \color{blue}{\left(-1 \cdot \left(\frac{1}{2} \cdot c\_n + \frac{-1}{2} \cdot c\_p\right)\right)}\right)} \]
    16. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-1 \cdot \left(\frac{1}{2} \cdot c\_n + \color{blue}{\left(\mathsf{neg}\left(\frac{1}{2}\right)\right)} \cdot c\_p\right)\right)\right)} \]
    17. cancel-sign-sub-invN/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-1 \cdot \color{blue}{\left(\frac{1}{2} \cdot c\_n - \frac{1}{2} \cdot c\_p\right)}\right)\right)} \]
    18. distribute-lft-out--N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-1 \cdot \color{blue}{\left(\frac{1}{2} \cdot \left(c\_n - c\_p\right)\right)}\right)\right)} \]
    19. associate-*r*N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \color{blue}{\left(\left(-1 \cdot \frac{1}{2}\right) \cdot \left(c\_n - c\_p\right)\right)}\right)} \]
    20. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(\color{blue}{\frac{-1}{2}} \cdot \left(c\_n - c\_p\right)\right)\right)} \]
    21. lower-*.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(\frac{-1}{2}, \left(c\_p - c\_n\right) \cdot t, s \cdot \color{blue}{\left(\frac{-1}{2} \cdot \left(c\_n - c\_p\right)\right)}\right)} \]
    22. lower--.f6499.4

      \[\leadsto e^{\mathsf{fma}\left(-0.5, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-0.5 \cdot \color{blue}{\left(c\_n - c\_p\right)}\right)\right)} \]
  9. Applied rewrites99.4%

    \[\leadsto e^{\color{blue}{\mathsf{fma}\left(-0.5, \left(c\_p - c\_n\right) \cdot t, s \cdot \left(-0.5 \cdot \left(c\_n - c\_p\right)\right)\right)}} \]
  10. Taylor expanded in t around 0

    \[\leadsto e^{\color{blue}{\frac{-1}{2} \cdot \left(s \cdot \left(c\_n - c\_p\right)\right)}} \]
  11. Step-by-step derivation
    1. lower-*.f64N/A

      \[\leadsto e^{\color{blue}{\frac{-1}{2} \cdot \left(s \cdot \left(c\_n - c\_p\right)\right)}} \]
    2. lower-*.f64N/A

      \[\leadsto e^{\frac{-1}{2} \cdot \color{blue}{\left(s \cdot \left(c\_n - c\_p\right)\right)}} \]
    3. lower--.f6498.1

      \[\leadsto e^{-0.5 \cdot \left(s \cdot \color{blue}{\left(c\_n - c\_p\right)}\right)} \]
  12. Applied rewrites98.1%

    \[\leadsto e^{\color{blue}{-0.5 \cdot \left(s \cdot \left(c\_n - c\_p\right)\right)}} \]
  13. Add Preprocessing

Alternative 5: 95.5% accurate, 8.1× speedup?

\[\begin{array}{l} \\ e^{0.5 \cdot \left(c\_n \cdot t\right)} \end{array} \]
(FPCore (c_p c_n t s) :precision binary64 (exp (* 0.5 (* c_n t))))
double code(double c_p, double c_n, double t, double s) {
	return exp((0.5 * (c_n * t)));
}
real(8) function code(c_p, c_n, t, s)
    real(8), intent (in) :: c_p
    real(8), intent (in) :: c_n
    real(8), intent (in) :: t
    real(8), intent (in) :: s
    code = exp((0.5d0 * (c_n * t)))
end function
public static double code(double c_p, double c_n, double t, double s) {
	return Math.exp((0.5 * (c_n * t)));
}
def code(c_p, c_n, t, s):
	return math.exp((0.5 * (c_n * t)))
function code(c_p, c_n, t, s)
	return exp(Float64(0.5 * Float64(c_n * t)))
end
function tmp = code(c_p, c_n, t, s)
	tmp = exp((0.5 * (c_n * t)));
end
code[c$95$p_, c$95$n_, t_, s_] := N[Exp[N[(0.5 * N[(c$95$n * t), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
e^{0.5 \cdot \left(c\_n \cdot t\right)}
\end{array}
Derivation
  1. Initial program 89.6%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Add Preprocessing
  3. Applied rewrites94.1%

    \[\leadsto \color{blue}{e^{\mathsf{fma}\left(c\_p, \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right), c\_n \cdot \left(\mathsf{log1p}\left(\frac{1}{-1 - e^{-s}}\right) - \mathsf{log1p}\left(\frac{-1}{1 + e^{-t}}\right)\right)\right)}} \]
  4. Taylor expanded in t around 0

    \[\leadsto e^{\color{blue}{c\_n \cdot \left(\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}\right) + \left(c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
  5. Step-by-step derivation
    1. lower-fma.f64N/A

      \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
    2. lower--.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    3. sub-negN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \log \color{blue}{\left(1 + \left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    4. lower-log1p.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\mathsf{log1p}\left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    5. distribute-neg-fracN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{\mathsf{neg}\left(1\right)}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    6. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{\color{blue}{-1}}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    7. lower-/.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    8. lower-+.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{\color{blue}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    9. lower-exp.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    10. lower-neg.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    11. lower-log.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \color{blue}{\log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
  6. Applied rewrites98.1%

    \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{-s}}\right) - \log 0.5, \mathsf{fma}\left(c\_p, \log 2 - \mathsf{log1p}\left(e^{-s}\right), t \cdot \mathsf{fma}\left(c\_n, 0.5, c\_p \cdot -0.5\right)\right)\right)}} \]
  7. Taylor expanded in s around 0

    \[\leadsto \color{blue}{e^{t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)}} \]
  8. Step-by-step derivation
    1. lower-exp.f64N/A

      \[\leadsto \color{blue}{e^{t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)}} \]
    2. *-commutativeN/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right) \cdot t}} \]
    3. metadata-evalN/A

      \[\leadsto e^{\left(\frac{-1}{2} \cdot c\_p + \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{2}\right)\right)} \cdot c\_n\right) \cdot t} \]
    4. cancel-sign-sub-invN/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot c\_p - \frac{-1}{2} \cdot c\_n\right)} \cdot t} \]
    5. distribute-lft-out--N/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot \left(c\_p - c\_n\right)\right)} \cdot t} \]
    6. associate-*l*N/A

      \[\leadsto e^{\color{blue}{\frac{-1}{2} \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
    7. lower-*.f64N/A

      \[\leadsto e^{\color{blue}{\frac{-1}{2} \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
    8. lower-*.f64N/A

      \[\leadsto e^{\frac{-1}{2} \cdot \color{blue}{\left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
    9. lower--.f6496.8

      \[\leadsto e^{-0.5 \cdot \left(\color{blue}{\left(c\_p - c\_n\right)} \cdot t\right)} \]
  9. Applied rewrites96.8%

    \[\leadsto \color{blue}{e^{-0.5 \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
  10. Taylor expanded in c_p around 0

    \[\leadsto \color{blue}{e^{\frac{1}{2} \cdot \left(c\_n \cdot t\right)}} \]
  11. Step-by-step derivation
    1. lower-exp.f64N/A

      \[\leadsto \color{blue}{e^{\frac{1}{2} \cdot \left(c\_n \cdot t\right)}} \]
    2. lower-*.f64N/A

      \[\leadsto e^{\color{blue}{\frac{1}{2} \cdot \left(c\_n \cdot t\right)}} \]
    3. *-commutativeN/A

      \[\leadsto e^{\frac{1}{2} \cdot \color{blue}{\left(t \cdot c\_n\right)}} \]
    4. lower-*.f6496.3

      \[\leadsto e^{0.5 \cdot \color{blue}{\left(t \cdot c\_n\right)}} \]
  12. Applied rewrites96.3%

    \[\leadsto \color{blue}{e^{0.5 \cdot \left(t \cdot c\_n\right)}} \]
  13. Final simplification96.3%

    \[\leadsto e^{0.5 \cdot \left(c\_n \cdot t\right)} \]
  14. Add Preprocessing

Alternative 6: 94.3% accurate, 8.1× speedup?

\[\begin{array}{l} \\ e^{-0.5 \cdot \left(c\_p \cdot t\right)} \end{array} \]
(FPCore (c_p c_n t s) :precision binary64 (exp (* -0.5 (* c_p t))))
double code(double c_p, double c_n, double t, double s) {
	return exp((-0.5 * (c_p * t)));
}
real(8) function code(c_p, c_n, t, s)
    real(8), intent (in) :: c_p
    real(8), intent (in) :: c_n
    real(8), intent (in) :: t
    real(8), intent (in) :: s
    code = exp(((-0.5d0) * (c_p * t)))
end function
public static double code(double c_p, double c_n, double t, double s) {
	return Math.exp((-0.5 * (c_p * t)));
}
def code(c_p, c_n, t, s):
	return math.exp((-0.5 * (c_p * t)))
function code(c_p, c_n, t, s)
	return exp(Float64(-0.5 * Float64(c_p * t)))
end
function tmp = code(c_p, c_n, t, s)
	tmp = exp((-0.5 * (c_p * t)));
end
code[c$95$p_, c$95$n_, t_, s_] := N[Exp[N[(-0.5 * N[(c$95$p * t), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
e^{-0.5 \cdot \left(c\_p \cdot t\right)}
\end{array}
Derivation
  1. Initial program 89.6%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Add Preprocessing
  3. Applied rewrites94.1%

    \[\leadsto \color{blue}{e^{\mathsf{fma}\left(c\_p, \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right), c\_n \cdot \left(\mathsf{log1p}\left(\frac{1}{-1 - e^{-s}}\right) - \mathsf{log1p}\left(\frac{-1}{1 + e^{-t}}\right)\right)\right)}} \]
  4. Taylor expanded in t around 0

    \[\leadsto e^{\color{blue}{c\_n \cdot \left(\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}\right) + \left(c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
  5. Step-by-step derivation
    1. lower-fma.f64N/A

      \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
    2. lower--.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    3. sub-negN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \log \color{blue}{\left(1 + \left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    4. lower-log1p.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\mathsf{log1p}\left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    5. distribute-neg-fracN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{\mathsf{neg}\left(1\right)}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    6. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{\color{blue}{-1}}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    7. lower-/.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    8. lower-+.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{\color{blue}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    9. lower-exp.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    10. lower-neg.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    11. lower-log.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \color{blue}{\log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
  6. Applied rewrites98.1%

    \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{-s}}\right) - \log 0.5, \mathsf{fma}\left(c\_p, \log 2 - \mathsf{log1p}\left(e^{-s}\right), t \cdot \mathsf{fma}\left(c\_n, 0.5, c\_p \cdot -0.5\right)\right)\right)}} \]
  7. Taylor expanded in s around 0

    \[\leadsto \color{blue}{e^{t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)}} \]
  8. Step-by-step derivation
    1. lower-exp.f64N/A

      \[\leadsto \color{blue}{e^{t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)}} \]
    2. *-commutativeN/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right) \cdot t}} \]
    3. metadata-evalN/A

      \[\leadsto e^{\left(\frac{-1}{2} \cdot c\_p + \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{2}\right)\right)} \cdot c\_n\right) \cdot t} \]
    4. cancel-sign-sub-invN/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot c\_p - \frac{-1}{2} \cdot c\_n\right)} \cdot t} \]
    5. distribute-lft-out--N/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot \left(c\_p - c\_n\right)\right)} \cdot t} \]
    6. associate-*l*N/A

      \[\leadsto e^{\color{blue}{\frac{-1}{2} \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
    7. lower-*.f64N/A

      \[\leadsto e^{\color{blue}{\frac{-1}{2} \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
    8. lower-*.f64N/A

      \[\leadsto e^{\frac{-1}{2} \cdot \color{blue}{\left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
    9. lower--.f6496.8

      \[\leadsto e^{-0.5 \cdot \left(\color{blue}{\left(c\_p - c\_n\right)} \cdot t\right)} \]
  9. Applied rewrites96.8%

    \[\leadsto \color{blue}{e^{-0.5 \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
  10. Taylor expanded in c_n around 0

    \[\leadsto \color{blue}{e^{\frac{-1}{2} \cdot \left(c\_p \cdot t\right)}} \]
  11. Step-by-step derivation
    1. lower-exp.f64N/A

      \[\leadsto \color{blue}{e^{\frac{-1}{2} \cdot \left(c\_p \cdot t\right)}} \]
    2. lower-*.f64N/A

      \[\leadsto e^{\color{blue}{\frac{-1}{2} \cdot \left(c\_p \cdot t\right)}} \]
    3. *-commutativeN/A

      \[\leadsto e^{\frac{-1}{2} \cdot \color{blue}{\left(t \cdot c\_p\right)}} \]
    4. lower-*.f6495.3

      \[\leadsto e^{-0.5 \cdot \color{blue}{\left(t \cdot c\_p\right)}} \]
  12. Applied rewrites95.3%

    \[\leadsto \color{blue}{e^{-0.5 \cdot \left(t \cdot c\_p\right)}} \]
  13. Final simplification95.3%

    \[\leadsto e^{-0.5 \cdot \left(c\_p \cdot t\right)} \]
  14. Add Preprocessing

Alternative 7: 94.0% accurate, 24.2× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(t, \mathsf{fma}\left(t \cdot 0.125, \left(c\_p - c\_n\right) \cdot \left(c\_p - c\_n\right), -0.5 \cdot \left(c\_p - c\_n\right)\right), 1\right) \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (fma
  t
  (fma (* t 0.125) (* (- c_p c_n) (- c_p c_n)) (* -0.5 (- c_p c_n)))
  1.0))
double code(double c_p, double c_n, double t, double s) {
	return fma(t, fma((t * 0.125), ((c_p - c_n) * (c_p - c_n)), (-0.5 * (c_p - c_n))), 1.0);
}
function code(c_p, c_n, t, s)
	return fma(t, fma(Float64(t * 0.125), Float64(Float64(c_p - c_n) * Float64(c_p - c_n)), Float64(-0.5 * Float64(c_p - c_n))), 1.0)
end
code[c$95$p_, c$95$n_, t_, s_] := N[(t * N[(N[(t * 0.125), $MachinePrecision] * N[(N[(c$95$p - c$95$n), $MachinePrecision] * N[(c$95$p - c$95$n), $MachinePrecision]), $MachinePrecision] + N[(-0.5 * N[(c$95$p - c$95$n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(t, \mathsf{fma}\left(t \cdot 0.125, \left(c\_p - c\_n\right) \cdot \left(c\_p - c\_n\right), -0.5 \cdot \left(c\_p - c\_n\right)\right), 1\right)
\end{array}
Derivation
  1. Initial program 89.6%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Add Preprocessing
  3. Applied rewrites94.1%

    \[\leadsto \color{blue}{e^{\mathsf{fma}\left(c\_p, \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right), c\_n \cdot \left(\mathsf{log1p}\left(\frac{1}{-1 - e^{-s}}\right) - \mathsf{log1p}\left(\frac{-1}{1 + e^{-t}}\right)\right)\right)}} \]
  4. Taylor expanded in t around 0

    \[\leadsto e^{\color{blue}{c\_n \cdot \left(\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}\right) + \left(c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
  5. Step-by-step derivation
    1. lower-fma.f64N/A

      \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
    2. lower--.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    3. sub-negN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \log \color{blue}{\left(1 + \left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    4. lower-log1p.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\mathsf{log1p}\left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    5. distribute-neg-fracN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{\mathsf{neg}\left(1\right)}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    6. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{\color{blue}{-1}}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    7. lower-/.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    8. lower-+.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{\color{blue}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    9. lower-exp.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    10. lower-neg.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    11. lower-log.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \color{blue}{\log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
  6. Applied rewrites98.1%

    \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{-s}}\right) - \log 0.5, \mathsf{fma}\left(c\_p, \log 2 - \mathsf{log1p}\left(e^{-s}\right), t \cdot \mathsf{fma}\left(c\_n, 0.5, c\_p \cdot -0.5\right)\right)\right)}} \]
  7. Taylor expanded in s around 0

    \[\leadsto \color{blue}{e^{t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)}} \]
  8. Step-by-step derivation
    1. lower-exp.f64N/A

      \[\leadsto \color{blue}{e^{t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)}} \]
    2. *-commutativeN/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right) \cdot t}} \]
    3. metadata-evalN/A

      \[\leadsto e^{\left(\frac{-1}{2} \cdot c\_p + \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{2}\right)\right)} \cdot c\_n\right) \cdot t} \]
    4. cancel-sign-sub-invN/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot c\_p - \frac{-1}{2} \cdot c\_n\right)} \cdot t} \]
    5. distribute-lft-out--N/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot \left(c\_p - c\_n\right)\right)} \cdot t} \]
    6. associate-*l*N/A

      \[\leadsto e^{\color{blue}{\frac{-1}{2} \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
    7. lower-*.f64N/A

      \[\leadsto e^{\color{blue}{\frac{-1}{2} \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
    8. lower-*.f64N/A

      \[\leadsto e^{\frac{-1}{2} \cdot \color{blue}{\left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
    9. lower--.f6496.8

      \[\leadsto e^{-0.5 \cdot \left(\color{blue}{\left(c\_p - c\_n\right)} \cdot t\right)} \]
  9. Applied rewrites96.8%

    \[\leadsto \color{blue}{e^{-0.5 \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
  10. Taylor expanded in t around 0

    \[\leadsto \color{blue}{1 + t \cdot \left(\frac{-1}{2} \cdot \left(c\_p - c\_n\right) + \frac{1}{8} \cdot \left(t \cdot {\left(c\_p - c\_n\right)}^{2}\right)\right)} \]
  11. Step-by-step derivation
    1. +-commutativeN/A

      \[\leadsto \color{blue}{t \cdot \left(\frac{-1}{2} \cdot \left(c\_p - c\_n\right) + \frac{1}{8} \cdot \left(t \cdot {\left(c\_p - c\_n\right)}^{2}\right)\right) + 1} \]
    2. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(t, \frac{-1}{2} \cdot \left(c\_p - c\_n\right) + \frac{1}{8} \cdot \left(t \cdot {\left(c\_p - c\_n\right)}^{2}\right), 1\right)} \]
    3. +-commutativeN/A

      \[\leadsto \mathsf{fma}\left(t, \color{blue}{\frac{1}{8} \cdot \left(t \cdot {\left(c\_p - c\_n\right)}^{2}\right) + \frac{-1}{2} \cdot \left(c\_p - c\_n\right)}, 1\right) \]
    4. associate-*r*N/A

      \[\leadsto \mathsf{fma}\left(t, \color{blue}{\left(\frac{1}{8} \cdot t\right) \cdot {\left(c\_p - c\_n\right)}^{2}} + \frac{-1}{2} \cdot \left(c\_p - c\_n\right), 1\right) \]
    5. lower-fma.f64N/A

      \[\leadsto \mathsf{fma}\left(t, \color{blue}{\mathsf{fma}\left(\frac{1}{8} \cdot t, {\left(c\_p - c\_n\right)}^{2}, \frac{-1}{2} \cdot \left(c\_p - c\_n\right)\right)}, 1\right) \]
    6. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(t, \mathsf{fma}\left(\color{blue}{\frac{1}{8} \cdot t}, {\left(c\_p - c\_n\right)}^{2}, \frac{-1}{2} \cdot \left(c\_p - c\_n\right)\right), 1\right) \]
    7. unpow2N/A

      \[\leadsto \mathsf{fma}\left(t, \mathsf{fma}\left(\frac{1}{8} \cdot t, \color{blue}{\left(c\_p - c\_n\right) \cdot \left(c\_p - c\_n\right)}, \frac{-1}{2} \cdot \left(c\_p - c\_n\right)\right), 1\right) \]
    8. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(t, \mathsf{fma}\left(\frac{1}{8} \cdot t, \color{blue}{\left(c\_p - c\_n\right) \cdot \left(c\_p - c\_n\right)}, \frac{-1}{2} \cdot \left(c\_p - c\_n\right)\right), 1\right) \]
    9. lower--.f64N/A

      \[\leadsto \mathsf{fma}\left(t, \mathsf{fma}\left(\frac{1}{8} \cdot t, \color{blue}{\left(c\_p - c\_n\right)} \cdot \left(c\_p - c\_n\right), \frac{-1}{2} \cdot \left(c\_p - c\_n\right)\right), 1\right) \]
    10. lower--.f64N/A

      \[\leadsto \mathsf{fma}\left(t, \mathsf{fma}\left(\frac{1}{8} \cdot t, \left(c\_p - c\_n\right) \cdot \color{blue}{\left(c\_p - c\_n\right)}, \frac{-1}{2} \cdot \left(c\_p - c\_n\right)\right), 1\right) \]
    11. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(t, \mathsf{fma}\left(\frac{1}{8} \cdot t, \left(c\_p - c\_n\right) \cdot \left(c\_p - c\_n\right), \color{blue}{\frac{-1}{2} \cdot \left(c\_p - c\_n\right)}\right), 1\right) \]
    12. lower--.f6494.9

      \[\leadsto \mathsf{fma}\left(t, \mathsf{fma}\left(0.125 \cdot t, \left(c\_p - c\_n\right) \cdot \left(c\_p - c\_n\right), -0.5 \cdot \color{blue}{\left(c\_p - c\_n\right)}\right), 1\right) \]
  12. Applied rewrites94.9%

    \[\leadsto \color{blue}{\mathsf{fma}\left(t, \mathsf{fma}\left(0.125 \cdot t, \left(c\_p - c\_n\right) \cdot \left(c\_p - c\_n\right), -0.5 \cdot \left(c\_p - c\_n\right)\right), 1\right)} \]
  13. Final simplification94.9%

    \[\leadsto \mathsf{fma}\left(t, \mathsf{fma}\left(t \cdot 0.125, \left(c\_p - c\_n\right) \cdot \left(c\_p - c\_n\right), -0.5 \cdot \left(c\_p - c\_n\right)\right), 1\right) \]
  14. Add Preprocessing

Alternative 8: 94.0% accurate, 59.7× speedup?

\[\begin{array}{l} \\ \mathsf{fma}\left(-0.5, \left(c\_p - c\_n\right) \cdot t, 1\right) \end{array} \]
(FPCore (c_p c_n t s) :precision binary64 (fma -0.5 (* (- c_p c_n) t) 1.0))
double code(double c_p, double c_n, double t, double s) {
	return fma(-0.5, ((c_p - c_n) * t), 1.0);
}
function code(c_p, c_n, t, s)
	return fma(-0.5, Float64(Float64(c_p - c_n) * t), 1.0)
end
code[c$95$p_, c$95$n_, t_, s_] := N[(-0.5 * N[(N[(c$95$p - c$95$n), $MachinePrecision] * t), $MachinePrecision] + 1.0), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{fma}\left(-0.5, \left(c\_p - c\_n\right) \cdot t, 1\right)
\end{array}
Derivation
  1. Initial program 89.6%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Add Preprocessing
  3. Applied rewrites94.1%

    \[\leadsto \color{blue}{e^{\mathsf{fma}\left(c\_p, \left(-\mathsf{log1p}\left(e^{-s}\right)\right) - \left(-\mathsf{log1p}\left(e^{-t}\right)\right), c\_n \cdot \left(\mathsf{log1p}\left(\frac{1}{-1 - e^{-s}}\right) - \mathsf{log1p}\left(\frac{-1}{1 + e^{-t}}\right)\right)\right)}} \]
  4. Taylor expanded in t around 0

    \[\leadsto e^{\color{blue}{c\_n \cdot \left(\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}\right) + \left(c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
  5. Step-by-step derivation
    1. lower-fma.f64N/A

      \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)}} \]
    2. lower--.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    3. sub-negN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \log \color{blue}{\left(1 + \left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    4. lower-log1p.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \color{blue}{\mathsf{log1p}\left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)} - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    5. distribute-neg-fracN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{\mathsf{neg}\left(1\right)}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    6. metadata-evalN/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{\color{blue}{-1}}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    7. lower-/.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\color{blue}{\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    8. lower-+.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{\color{blue}{1 + e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    9. lower-exp.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    10. lower-neg.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right) - \log \frac{1}{2}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
    11. lower-log.f64N/A

      \[\leadsto e^{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \color{blue}{\log \frac{1}{2}}, c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)\right)} \]
  6. Applied rewrites98.1%

    \[\leadsto e^{\color{blue}{\mathsf{fma}\left(c\_n, \mathsf{log1p}\left(\frac{-1}{1 + e^{-s}}\right) - \log 0.5, \mathsf{fma}\left(c\_p, \log 2 - \mathsf{log1p}\left(e^{-s}\right), t \cdot \mathsf{fma}\left(c\_n, 0.5, c\_p \cdot -0.5\right)\right)\right)}} \]
  7. Taylor expanded in s around 0

    \[\leadsto \color{blue}{e^{t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)}} \]
  8. Step-by-step derivation
    1. lower-exp.f64N/A

      \[\leadsto \color{blue}{e^{t \cdot \left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right)}} \]
    2. *-commutativeN/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot c\_p + \frac{1}{2} \cdot c\_n\right) \cdot t}} \]
    3. metadata-evalN/A

      \[\leadsto e^{\left(\frac{-1}{2} \cdot c\_p + \color{blue}{\left(\mathsf{neg}\left(\frac{-1}{2}\right)\right)} \cdot c\_n\right) \cdot t} \]
    4. cancel-sign-sub-invN/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot c\_p - \frac{-1}{2} \cdot c\_n\right)} \cdot t} \]
    5. distribute-lft-out--N/A

      \[\leadsto e^{\color{blue}{\left(\frac{-1}{2} \cdot \left(c\_p - c\_n\right)\right)} \cdot t} \]
    6. associate-*l*N/A

      \[\leadsto e^{\color{blue}{\frac{-1}{2} \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
    7. lower-*.f64N/A

      \[\leadsto e^{\color{blue}{\frac{-1}{2} \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
    8. lower-*.f64N/A

      \[\leadsto e^{\frac{-1}{2} \cdot \color{blue}{\left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
    9. lower--.f6496.8

      \[\leadsto e^{-0.5 \cdot \left(\color{blue}{\left(c\_p - c\_n\right)} \cdot t\right)} \]
  9. Applied rewrites96.8%

    \[\leadsto \color{blue}{e^{-0.5 \cdot \left(\left(c\_p - c\_n\right) \cdot t\right)}} \]
  10. Taylor expanded in t around 0

    \[\leadsto \color{blue}{1 + \frac{-1}{2} \cdot \left(t \cdot \left(c\_p - c\_n\right)\right)} \]
  11. Step-by-step derivation
    1. +-commutativeN/A

      \[\leadsto \color{blue}{\frac{-1}{2} \cdot \left(t \cdot \left(c\_p - c\_n\right)\right) + 1} \]
    2. lower-fma.f64N/A

      \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{2}, t \cdot \left(c\_p - c\_n\right), 1\right)} \]
    3. lower-*.f64N/A

      \[\leadsto \mathsf{fma}\left(\frac{-1}{2}, \color{blue}{t \cdot \left(c\_p - c\_n\right)}, 1\right) \]
    4. lower--.f6494.9

      \[\leadsto \mathsf{fma}\left(-0.5, t \cdot \color{blue}{\left(c\_p - c\_n\right)}, 1\right) \]
  12. Applied rewrites94.9%

    \[\leadsto \color{blue}{\mathsf{fma}\left(-0.5, t \cdot \left(c\_p - c\_n\right), 1\right)} \]
  13. Final simplification94.9%

    \[\leadsto \mathsf{fma}\left(-0.5, \left(c\_p - c\_n\right) \cdot t, 1\right) \]
  14. Add Preprocessing

Alternative 9: 94.0% accurate, 896.0× speedup?

\[\begin{array}{l} \\ 1 \end{array} \]
(FPCore (c_p c_n t s) :precision binary64 1.0)
double code(double c_p, double c_n, double t, double s) {
	return 1.0;
}
real(8) function code(c_p, c_n, t, s)
    real(8), intent (in) :: c_p
    real(8), intent (in) :: c_n
    real(8), intent (in) :: t
    real(8), intent (in) :: s
    code = 1.0d0
end function
public static double code(double c_p, double c_n, double t, double s) {
	return 1.0;
}
def code(c_p, c_n, t, s):
	return 1.0
function code(c_p, c_n, t, s)
	return 1.0
end
function tmp = code(c_p, c_n, t, s)
	tmp = 1.0;
end
code[c$95$p_, c$95$n_, t_, s_] := 1.0
\begin{array}{l}

\\
1
\end{array}
Derivation
  1. Initial program 89.6%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Add Preprocessing
  3. Taylor expanded in c_p around 0

    \[\leadsto \color{blue}{\frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
  4. Step-by-step derivation
    1. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
    2. lower-pow.f64N/A

      \[\leadsto \frac{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
    3. sub-negN/A

      \[\leadsto \frac{{\color{blue}{\left(1 + \left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)\right)}}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
    4. lower-+.f64N/A

      \[\leadsto \frac{{\color{blue}{\left(1 + \left(\mathsf{neg}\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)\right)\right)}}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
    5. distribute-neg-fracN/A

      \[\leadsto \frac{{\left(1 + \color{blue}{\frac{\mathsf{neg}\left(1\right)}{1 + e^{\mathsf{neg}\left(s\right)}}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
    6. metadata-evalN/A

      \[\leadsto \frac{{\left(1 + \frac{\color{blue}{-1}}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
    7. lower-/.f64N/A

      \[\leadsto \frac{{\left(1 + \color{blue}{\frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
    8. lower-+.f64N/A

      \[\leadsto \frac{{\left(1 + \frac{-1}{\color{blue}{1 + e^{\mathsf{neg}\left(s\right)}}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
    9. lower-exp.f64N/A

      \[\leadsto \frac{{\left(1 + \frac{-1}{1 + \color{blue}{e^{\mathsf{neg}\left(s\right)}}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
    10. lower-neg.f64N/A

      \[\leadsto \frac{{\left(1 + \frac{-1}{1 + e^{\color{blue}{\mathsf{neg}\left(s\right)}}}\right)}^{c\_n}}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}} \]
    11. lower-pow.f64N/A

      \[\leadsto \frac{{\left(1 + \frac{-1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
  5. Applied rewrites95.6%

    \[\leadsto \color{blue}{\frac{{\left(1 + \frac{-1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(1 + \frac{-1}{1 + e^{-t}}\right)}^{c\_n}}} \]
  6. Taylor expanded in c_n around 0

    \[\leadsto \color{blue}{1} \]
  7. Step-by-step derivation
    1. Applied rewrites94.8%

      \[\leadsto \color{blue}{1} \]
    2. Add Preprocessing

    Developer Target 1: 96.0% accurate, 1.4× speedup?

    \[\begin{array}{l} \\ {\left(\frac{1 + e^{-t}}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(\frac{1 + e^{t}}{1 + e^{s}}\right)}^{c\_n} \end{array} \]
    (FPCore (c_p c_n t s)
     :precision binary64
     (*
      (pow (/ (+ 1.0 (exp (- t))) (+ 1.0 (exp (- s)))) c_p)
      (pow (/ (+ 1.0 (exp t)) (+ 1.0 (exp s))) c_n)))
    double code(double c_p, double c_n, double t, double s) {
    	return pow(((1.0 + exp(-t)) / (1.0 + exp(-s))), c_p) * pow(((1.0 + exp(t)) / (1.0 + exp(s))), c_n);
    }
    
    real(8) function code(c_p, c_n, t, s)
        real(8), intent (in) :: c_p
        real(8), intent (in) :: c_n
        real(8), intent (in) :: t
        real(8), intent (in) :: s
        code = (((1.0d0 + exp(-t)) / (1.0d0 + exp(-s))) ** c_p) * (((1.0d0 + exp(t)) / (1.0d0 + exp(s))) ** c_n)
    end function
    
    public static double code(double c_p, double c_n, double t, double s) {
    	return Math.pow(((1.0 + Math.exp(-t)) / (1.0 + Math.exp(-s))), c_p) * Math.pow(((1.0 + Math.exp(t)) / (1.0 + Math.exp(s))), c_n);
    }
    
    def code(c_p, c_n, t, s):
    	return math.pow(((1.0 + math.exp(-t)) / (1.0 + math.exp(-s))), c_p) * math.pow(((1.0 + math.exp(t)) / (1.0 + math.exp(s))), c_n)
    
    function code(c_p, c_n, t, s)
    	return Float64((Float64(Float64(1.0 + exp(Float64(-t))) / Float64(1.0 + exp(Float64(-s)))) ^ c_p) * (Float64(Float64(1.0 + exp(t)) / Float64(1.0 + exp(s))) ^ c_n))
    end
    
    function tmp = code(c_p, c_n, t, s)
    	tmp = (((1.0 + exp(-t)) / (1.0 + exp(-s))) ^ c_p) * (((1.0 + exp(t)) / (1.0 + exp(s))) ^ c_n);
    end
    
    code[c$95$p_, c$95$n_, t_, s_] := N[(N[Power[N[(N[(1.0 + N[Exp[(-t)], $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[Exp[(-s)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], c$95$p], $MachinePrecision] * N[Power[N[(N[(1.0 + N[Exp[t], $MachinePrecision]), $MachinePrecision] / N[(1.0 + N[Exp[s], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], c$95$n], $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    {\left(\frac{1 + e^{-t}}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(\frac{1 + e^{t}}{1 + e^{s}}\right)}^{c\_n}
    \end{array}
    

    Reproduce

    ?
    herbie shell --seed 2024216 
    (FPCore (c_p c_n t s)
      :name "Harley's example"
      :precision binary64
      :pre (and (< 0.0 c_p) (< 0.0 c_n))
    
      :alt
      (! :herbie-platform default (* (pow (/ (+ 1 (exp (- t))) (+ 1 (exp (- s)))) c_p) (pow (/ (+ 1 (exp t)) (+ 1 (exp s))) c_n)))
    
      (/ (* (pow (/ 1.0 (+ 1.0 (exp (- s)))) c_p) (pow (- 1.0 (/ 1.0 (+ 1.0 (exp (- s))))) c_n)) (* (pow (/ 1.0 (+ 1.0 (exp (- t)))) c_p) (pow (- 1.0 (/ 1.0 (+ 1.0 (exp (- t))))) c_n))))