Harley's example

Percentage Accurate: 90.9% → 98.1%
Time: 1.3min
Alternatives: 5
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));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(c_p, c_n, t, s)
use fmin_fmax_functions
    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 5 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: 90.9% 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));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

real(8) function code(c_p, c_n, t, s)
use fmin_fmax_functions
    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: 98.1% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_1 := e^{-s}\\ t_2 := \mathsf{log1p}\left(t\_1\right)\\ t_3 := e^{\mathsf{fma}\left(\log \left(1 - e^{-t\_2}\right), c\_n, \left(-c\_p\right) \cdot t\_2\right) - \mathsf{fma}\left(-c\_p, \log 2, \log 0.5 \cdot c\_n\right)}\\ \mathbf{if}\;t \leq -0.35:\\ \;\;\;\;\frac{{\left(1 - \frac{1}{t\_1 + 1}\right)}^{c\_n}}{\mathsf{fma}\left(\log 0.5, c\_n, 1\right)}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(t\_3 \cdot \left(-0.5 \cdot \left(c\_n - c\_p\right)\right), -t, t\_3\right)\\ \end{array} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (let* ((t_1 (exp (- s)))
        (t_2 (log1p t_1))
        (t_3
         (exp
          (-
           (fma (log (- 1.0 (exp (- t_2)))) c_n (* (- c_p) t_2))
           (fma (- c_p) (log 2.0) (* (log 0.5) c_n))))))
   (if (<= t -0.35)
     (/ (pow (- 1.0 (/ 1.0 (+ t_1 1.0))) c_n) (fma (log 0.5) c_n 1.0))
     (fma (* t_3 (* -0.5 (- c_n c_p))) (- t) t_3))))
double code(double c_p, double c_n, double t, double s) {
	double t_1 = exp(-s);
	double t_2 = log1p(t_1);
	double t_3 = exp((fma(log((1.0 - exp(-t_2))), c_n, (-c_p * t_2)) - fma(-c_p, log(2.0), (log(0.5) * c_n))));
	double tmp;
	if (t <= -0.35) {
		tmp = pow((1.0 - (1.0 / (t_1 + 1.0))), c_n) / fma(log(0.5), c_n, 1.0);
	} else {
		tmp = fma((t_3 * (-0.5 * (c_n - c_p))), -t, t_3);
	}
	return tmp;
}
function code(c_p, c_n, t, s)
	t_1 = exp(Float64(-s))
	t_2 = log1p(t_1)
	t_3 = exp(Float64(fma(log(Float64(1.0 - exp(Float64(-t_2)))), c_n, Float64(Float64(-c_p) * t_2)) - fma(Float64(-c_p), log(2.0), Float64(log(0.5) * c_n))))
	tmp = 0.0
	if (t <= -0.35)
		tmp = Float64((Float64(1.0 - Float64(1.0 / Float64(t_1 + 1.0))) ^ c_n) / fma(log(0.5), c_n, 1.0));
	else
		tmp = fma(Float64(t_3 * Float64(-0.5 * Float64(c_n - c_p))), Float64(-t), t_3);
	end
	return tmp
end
code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[Exp[(-s)], $MachinePrecision]}, Block[{t$95$2 = N[Log[1 + t$95$1], $MachinePrecision]}, Block[{t$95$3 = N[Exp[N[(N[(N[Log[N[(1.0 - N[Exp[(-t$95$2)], $MachinePrecision]), $MachinePrecision]], $MachinePrecision] * c$95$n + N[((-c$95$p) * t$95$2), $MachinePrecision]), $MachinePrecision] - N[((-c$95$p) * N[Log[2.0], $MachinePrecision] + N[(N[Log[0.5], $MachinePrecision] * c$95$n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]}, If[LessEqual[t, -0.35], N[(N[Power[N[(1.0 - N[(1.0 / N[(t$95$1 + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], c$95$n], $MachinePrecision] / N[(N[Log[0.5], $MachinePrecision] * c$95$n + 1.0), $MachinePrecision]), $MachinePrecision], N[(N[(t$95$3 * N[(-0.5 * N[(c$95$n - c$95$p), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * (-t) + t$95$3), $MachinePrecision]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_1 := e^{-s}\\
t_2 := \mathsf{log1p}\left(t\_1\right)\\
t_3 := e^{\mathsf{fma}\left(\log \left(1 - e^{-t\_2}\right), c\_n, \left(-c\_p\right) \cdot t\_2\right) - \mathsf{fma}\left(-c\_p, \log 2, \log 0.5 \cdot c\_n\right)}\\
\mathbf{if}\;t \leq -0.35:\\
\;\;\;\;\frac{{\left(1 - \frac{1}{t\_1 + 1}\right)}^{c\_n}}{\mathsf{fma}\left(\log 0.5, c\_n, 1\right)}\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(t\_3 \cdot \left(-0.5 \cdot \left(c\_n - c\_p\right)\right), -t, t\_3\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if t < -0.34999999999999998

    1. Initial program 16.8%

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

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

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

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

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

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

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

        \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
    5. Applied rewrites92.5%

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

      \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{1 + \color{blue}{c\_n \cdot \log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}} \]
    7. Step-by-step derivation
      1. Applied rewrites92.5%

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

        \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\mathsf{fma}\left(\log \left(1 - e^{\mathsf{neg}\left(\log 2\right)}\right), c\_n, 1\right)} \]
      3. Step-by-step derivation
        1. Applied rewrites92.5%

          \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\mathsf{fma}\left(\log 0.5, c\_n, 1\right)} \]

        if -0.34999999999999998 < t

        1. Initial program 91.0%

          \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
        2. Add Preprocessing
        3. Applied rewrites97.1%

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

          \[\leadsto \color{blue}{e^{\left(-1 \cdot \left(c\_p \cdot \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + c\_n \cdot \log \left(1 - e^{\mathsf{neg}\left(\log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right)}\right)\right) - \left(-1 \cdot \left(c\_p \cdot \log 2\right) + c\_n \cdot \log \left(1 - e^{\mathsf{neg}\left(\log 2\right)}\right)\right)} + -1 \cdot \left(t \cdot \left(e^{\left(-1 \cdot \left(c\_p \cdot \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + c\_n \cdot \log \left(1 - e^{\mathsf{neg}\left(\log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right)}\right)\right) - \left(-1 \cdot \left(c\_p \cdot \log 2\right) + c\_n \cdot \log \left(1 - e^{\mathsf{neg}\left(\log 2\right)}\right)\right)} \cdot \left(\frac{-1}{2} \cdot \frac{c\_n \cdot e^{\mathsf{neg}\left(\log 2\right)}}{1 - e^{\mathsf{neg}\left(\log 2\right)}} + \frac{1}{2} \cdot c\_p\right)\right)\right)} \]
        5. Applied rewrites98.8%

          \[\leadsto \color{blue}{\mathsf{fma}\left(e^{\mathsf{fma}\left(\log \left(1 - e^{-\mathsf{log1p}\left(e^{-s}\right)}\right), c\_n, \left(-c\_p\right) \cdot \mathsf{log1p}\left(e^{-s}\right)\right) - \mathsf{fma}\left(-c\_p, \log 2, \log 0.5 \cdot c\_n\right)} \cdot \left(-0.5 \cdot \left(c\_n \cdot 1 - c\_p\right)\right), -t, e^{\mathsf{fma}\left(\log \left(1 - e^{-\mathsf{log1p}\left(e^{-s}\right)}\right), c\_n, \left(-c\_p\right) \cdot \mathsf{log1p}\left(e^{-s}\right)\right) - \mathsf{fma}\left(-c\_p, \log 2, \log 0.5 \cdot c\_n\right)}\right)} \]
      4. Recombined 2 regimes into one program.
      5. Final simplification98.5%

        \[\leadsto \begin{array}{l} \mathbf{if}\;t \leq -0.35:\\ \;\;\;\;\frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\mathsf{fma}\left(\log 0.5, c\_n, 1\right)}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(e^{\mathsf{fma}\left(\log \left(1 - e^{-\mathsf{log1p}\left(e^{-s}\right)}\right), c\_n, \left(-c\_p\right) \cdot \mathsf{log1p}\left(e^{-s}\right)\right) - \mathsf{fma}\left(-c\_p, \log 2, \log 0.5 \cdot c\_n\right)} \cdot \left(-0.5 \cdot \left(c\_n - c\_p\right)\right), -t, e^{\mathsf{fma}\left(\log \left(1 - e^{-\mathsf{log1p}\left(e^{-s}\right)}\right), c\_n, \left(-c\_p\right) \cdot \mathsf{log1p}\left(e^{-s}\right)\right) - \mathsf{fma}\left(-c\_p, \log 2, \log 0.5 \cdot c\_n\right)}\right)\\ \end{array} \]
      6. Add Preprocessing

      Alternative 2: 96.1% accurate, 1.7× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_1 := e^{-s}\\ \mathbf{if}\;c\_p \leq 1.5 \cdot 10^{-21}:\\ \;\;\;\;\frac{{\left(1 - \frac{1}{t\_1 + 1}\right)}^{c\_n}}{\mathsf{fma}\left(\log 0.5, c\_n, 1\right)}\\ \mathbf{else}:\\ \;\;\;\;e^{\mathsf{log1p}\left(t\_1\right) \cdot \left(-c\_p\right) + \mathsf{log1p}\left(e^{-t}\right) \cdot c\_p}\\ \end{array} \end{array} \]
      (FPCore (c_p c_n t s)
       :precision binary64
       (let* ((t_1 (exp (- s))))
         (if (<= c_p 1.5e-21)
           (/ (pow (- 1.0 (/ 1.0 (+ t_1 1.0))) c_n) (fma (log 0.5) c_n 1.0))
           (exp (+ (* (log1p t_1) (- c_p)) (* (log1p (exp (- t))) c_p))))))
      double code(double c_p, double c_n, double t, double s) {
      	double t_1 = exp(-s);
      	double tmp;
      	if (c_p <= 1.5e-21) {
      		tmp = pow((1.0 - (1.0 / (t_1 + 1.0))), c_n) / fma(log(0.5), c_n, 1.0);
      	} else {
      		tmp = exp(((log1p(t_1) * -c_p) + (log1p(exp(-t)) * c_p)));
      	}
      	return tmp;
      }
      
      function code(c_p, c_n, t, s)
      	t_1 = exp(Float64(-s))
      	tmp = 0.0
      	if (c_p <= 1.5e-21)
      		tmp = Float64((Float64(1.0 - Float64(1.0 / Float64(t_1 + 1.0))) ^ c_n) / fma(log(0.5), c_n, 1.0));
      	else
      		tmp = exp(Float64(Float64(log1p(t_1) * Float64(-c_p)) + Float64(log1p(exp(Float64(-t))) * c_p)));
      	end
      	return tmp
      end
      
      code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[Exp[(-s)], $MachinePrecision]}, If[LessEqual[c$95$p, 1.5e-21], N[(N[Power[N[(1.0 - N[(1.0 / N[(t$95$1 + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], c$95$n], $MachinePrecision] / N[(N[Log[0.5], $MachinePrecision] * c$95$n + 1.0), $MachinePrecision]), $MachinePrecision], N[Exp[N[(N[(N[Log[1 + t$95$1], $MachinePrecision] * (-c$95$p)), $MachinePrecision] + N[(N[Log[1 + N[Exp[(-t)], $MachinePrecision]], $MachinePrecision] * c$95$p), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_1 := e^{-s}\\
      \mathbf{if}\;c\_p \leq 1.5 \cdot 10^{-21}:\\
      \;\;\;\;\frac{{\left(1 - \frac{1}{t\_1 + 1}\right)}^{c\_n}}{\mathsf{fma}\left(\log 0.5, c\_n, 1\right)}\\
      
      \mathbf{else}:\\
      \;\;\;\;e^{\mathsf{log1p}\left(t\_1\right) \cdot \left(-c\_p\right) + \mathsf{log1p}\left(e^{-t}\right) \cdot c\_p}\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if c_p < 1.49999999999999996e-21

        1. Initial program 88.9%

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

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

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

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

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

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

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

            \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
        5. Applied rewrites94.6%

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

          \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{1 + \color{blue}{c\_n \cdot \log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}} \]
        7. Step-by-step derivation
          1. Applied rewrites95.7%

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

            \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\mathsf{fma}\left(\log \left(1 - e^{\mathsf{neg}\left(\log 2\right)}\right), c\_n, 1\right)} \]
          3. Step-by-step derivation
            1. Applied rewrites97.0%

              \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\mathsf{fma}\left(\log 0.5, c\_n, 1\right)} \]

            if 1.49999999999999996e-21 < c_p

            1. Initial program 76.5%

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

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

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

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

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

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

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

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

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

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

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

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

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

                \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
              13. lower-neg.f6479.4

                \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
            5. Applied rewrites79.4%

              \[\leadsto \color{blue}{\frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{-t} + 1}\right)}^{c\_p}}} \]
            6. Step-by-step derivation
              1. Applied rewrites99.2%

                \[\leadsto e^{\mathsf{log1p}\left(e^{-s}\right) \cdot \left(-c\_p\right) - \mathsf{log1p}\left(e^{-t}\right) \cdot \left(-c\_p\right)} \]
            7. Recombined 2 regimes into one program.
            8. Final simplification97.3%

              \[\leadsto \begin{array}{l} \mathbf{if}\;c\_p \leq 1.5 \cdot 10^{-21}:\\ \;\;\;\;\frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\mathsf{fma}\left(\log 0.5, c\_n, 1\right)}\\ \mathbf{else}:\\ \;\;\;\;e^{\mathsf{log1p}\left(e^{-s}\right) \cdot \left(-c\_p\right) + \mathsf{log1p}\left(e^{-t}\right) \cdot c\_p}\\ \end{array} \]
            9. Add Preprocessing

            Alternative 3: 95.2% accurate, 2.6× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} t_1 := e^{-s} + 1\\ \mathbf{if}\;s \leq -3300000:\\ \;\;\;\;\frac{{t\_1}^{\left(-c\_p\right)}}{\mathsf{fma}\left(-c\_p, \log 2, 1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{{\left(1 - \frac{1}{t\_1}\right)}^{c\_n}}{\mathsf{fma}\left(\log 0.5, c\_n, 1\right)}\\ \end{array} \end{array} \]
            (FPCore (c_p c_n t s)
             :precision binary64
             (let* ((t_1 (+ (exp (- s)) 1.0)))
               (if (<= s -3300000.0)
                 (/ (pow t_1 (- c_p)) (fma (- c_p) (log 2.0) 1.0))
                 (/ (pow (- 1.0 (/ 1.0 t_1)) c_n) (fma (log 0.5) c_n 1.0)))))
            double code(double c_p, double c_n, double t, double s) {
            	double t_1 = exp(-s) + 1.0;
            	double tmp;
            	if (s <= -3300000.0) {
            		tmp = pow(t_1, -c_p) / fma(-c_p, log(2.0), 1.0);
            	} else {
            		tmp = pow((1.0 - (1.0 / t_1)), c_n) / fma(log(0.5), c_n, 1.0);
            	}
            	return tmp;
            }
            
            function code(c_p, c_n, t, s)
            	t_1 = Float64(exp(Float64(-s)) + 1.0)
            	tmp = 0.0
            	if (s <= -3300000.0)
            		tmp = Float64((t_1 ^ Float64(-c_p)) / fma(Float64(-c_p), log(2.0), 1.0));
            	else
            		tmp = Float64((Float64(1.0 - Float64(1.0 / t_1)) ^ c_n) / fma(log(0.5), c_n, 1.0));
            	end
            	return tmp
            end
            
            code[c$95$p_, c$95$n_, t_, s_] := Block[{t$95$1 = N[(N[Exp[(-s)], $MachinePrecision] + 1.0), $MachinePrecision]}, If[LessEqual[s, -3300000.0], N[(N[Power[t$95$1, (-c$95$p)], $MachinePrecision] / N[((-c$95$p) * N[Log[2.0], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision], N[(N[Power[N[(1.0 - N[(1.0 / t$95$1), $MachinePrecision]), $MachinePrecision], c$95$n], $MachinePrecision] / N[(N[Log[0.5], $MachinePrecision] * c$95$n + 1.0), $MachinePrecision]), $MachinePrecision]]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            t_1 := e^{-s} + 1\\
            \mathbf{if}\;s \leq -3300000:\\
            \;\;\;\;\frac{{t\_1}^{\left(-c\_p\right)}}{\mathsf{fma}\left(-c\_p, \log 2, 1\right)}\\
            
            \mathbf{else}:\\
            \;\;\;\;\frac{{\left(1 - \frac{1}{t\_1}\right)}^{c\_n}}{\mathsf{fma}\left(\log 0.5, c\_n, 1\right)}\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 2 regimes
            2. if s < -3.3e6

              1. Initial program 44.8%

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

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

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

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

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

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

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

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

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

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

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

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

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

                  \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
                13. lower-neg.f6455.9

                  \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
              5. Applied rewrites55.9%

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

                \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{1 + \color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}} \]
              7. Step-by-step derivation
                1. Applied rewrites89.2%

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

                  \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{\mathsf{fma}\left(-c\_p, \log 2, 1\right)} \]
                3. Step-by-step derivation
                  1. Applied rewrites89.2%

                    \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{\mathsf{fma}\left(-c\_p, \log 2, 1\right)} \]
                  2. Step-by-step derivation
                    1. Applied rewrites89.2%

                      \[\leadsto \frac{{\left(e^{-s} + 1\right)}^{\left(-1 \cdot c\_p\right)}}{\mathsf{fma}\left(\color{blue}{-c\_p}, \log 2, 1\right)} \]

                    if -3.3e6 < s

                    1. Initial program 88.8%

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

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

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

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

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

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

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

                        \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\color{blue}{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}^{c\_n}}} \]
                    5. Applied rewrites94.4%

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

                      \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{1 + \color{blue}{c\_n \cdot \log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}} \]
                    7. Step-by-step derivation
                      1. Applied rewrites95.1%

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

                        \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\mathsf{fma}\left(\log \left(1 - e^{\mathsf{neg}\left(\log 2\right)}\right), c\_n, 1\right)} \]
                      3. Step-by-step derivation
                        1. Applied rewrites96.3%

                          \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\mathsf{fma}\left(\log 0.5, c\_n, 1\right)} \]
                      4. Recombined 2 regimes into one program.
                      5. Final simplification96.0%

                        \[\leadsto \begin{array}{l} \mathbf{if}\;s \leq -3300000:\\ \;\;\;\;\frac{{\left(e^{-s} + 1\right)}^{\left(-c\_p\right)}}{\mathsf{fma}\left(-c\_p, \log 2, 1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\mathsf{fma}\left(\log 0.5, c\_n, 1\right)}\\ \end{array} \]
                      6. Add Preprocessing

                      Alternative 4: 96.1% accurate, 2.7× speedup?

                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;s \leq -750000000:\\ \;\;\;\;\frac{{\left(e^{-s} + 1\right)}^{\left(-c\_p\right)}}{\mathsf{fma}\left(-c\_p, \log 2, 1\right)}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
                      (FPCore (c_p c_n t s)
                       :precision binary64
                       (if (<= s -750000000.0)
                         (/ (pow (+ (exp (- s)) 1.0) (- c_p)) (fma (- c_p) (log 2.0) 1.0))
                         1.0))
                      double code(double c_p, double c_n, double t, double s) {
                      	double tmp;
                      	if (s <= -750000000.0) {
                      		tmp = pow((exp(-s) + 1.0), -c_p) / fma(-c_p, log(2.0), 1.0);
                      	} else {
                      		tmp = 1.0;
                      	}
                      	return tmp;
                      }
                      
                      function code(c_p, c_n, t, s)
                      	tmp = 0.0
                      	if (s <= -750000000.0)
                      		tmp = Float64((Float64(exp(Float64(-s)) + 1.0) ^ Float64(-c_p)) / fma(Float64(-c_p), log(2.0), 1.0));
                      	else
                      		tmp = 1.0;
                      	end
                      	return tmp
                      end
                      
                      code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[s, -750000000.0], N[(N[Power[N[(N[Exp[(-s)], $MachinePrecision] + 1.0), $MachinePrecision], (-c$95$p)], $MachinePrecision] / N[((-c$95$p) * N[Log[2.0], $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision], 1.0]
                      
                      \begin{array}{l}
                      
                      \\
                      \begin{array}{l}
                      \mathbf{if}\;s \leq -750000000:\\
                      \;\;\;\;\frac{{\left(e^{-s} + 1\right)}^{\left(-c\_p\right)}}{\mathsf{fma}\left(-c\_p, \log 2, 1\right)}\\
                      
                      \mathbf{else}:\\
                      \;\;\;\;1\\
                      
                      
                      \end{array}
                      \end{array}
                      
                      Derivation
                      1. Split input into 2 regimes
                      2. if s < -7.5e8

                        1. Initial program 50.0%

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

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

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

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

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

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

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

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

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

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

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

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

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

                            \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
                          13. lower-neg.f6462.5

                            \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
                        5. Applied rewrites62.5%

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

                          \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{1 + \color{blue}{c\_p \cdot \log \left(\frac{1}{1 + e^{\mathsf{neg}\left(t\right)}}\right)}} \]
                        7. Step-by-step derivation
                          1. Applied rewrites100.0%

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

                            \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{\mathsf{fma}\left(-c\_p, \log 2, 1\right)} \]
                          3. Step-by-step derivation
                            1. Applied rewrites100.0%

                              \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{\mathsf{fma}\left(-c\_p, \log 2, 1\right)} \]
                            2. Step-by-step derivation
                              1. Applied rewrites100.0%

                                \[\leadsto \frac{{\left(e^{-s} + 1\right)}^{\left(-1 \cdot c\_p\right)}}{\mathsf{fma}\left(\color{blue}{-c\_p}, \log 2, 1\right)} \]

                              if -7.5e8 < s

                              1. Initial program 88.4%

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

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

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

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

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

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

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

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

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

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

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

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

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

                                  \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
                                13. lower-neg.f6490.8

                                  \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
                              5. Applied rewrites90.8%

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

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

                                  \[\leadsto 1 \]
                              8. Recombined 2 regimes into one program.
                              9. Final simplification95.0%

                                \[\leadsto \begin{array}{l} \mathbf{if}\;s \leq -750000000:\\ \;\;\;\;\frac{{\left(e^{-s} + 1\right)}^{\left(-c\_p\right)}}{\mathsf{fma}\left(-c\_p, \log 2, 1\right)}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]
                              10. Add Preprocessing

                              Alternative 5: 93.8% 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;
                              }
                              
                              module fmin_fmax_functions
                                  implicit none
                                  private
                                  public fmax
                                  public fmin
                              
                                  interface fmax
                                      module procedure fmax88
                                      module procedure fmax44
                                      module procedure fmax84
                                      module procedure fmax48
                                  end interface
                                  interface fmin
                                      module procedure fmin88
                                      module procedure fmin44
                                      module procedure fmin84
                                      module procedure fmin48
                                  end interface
                              contains
                                  real(8) function fmax88(x, y) result (res)
                                      real(8), intent (in) :: x
                                      real(8), intent (in) :: y
                                      res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                  end function
                                  real(4) function fmax44(x, y) result (res)
                                      real(4), intent (in) :: x
                                      real(4), intent (in) :: y
                                      res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                  end function
                                  real(8) function fmax84(x, y) result(res)
                                      real(8), intent (in) :: x
                                      real(4), intent (in) :: y
                                      res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                  end function
                                  real(8) function fmax48(x, y) result(res)
                                      real(4), intent (in) :: x
                                      real(8), intent (in) :: y
                                      res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                  end function
                                  real(8) function fmin88(x, y) result (res)
                                      real(8), intent (in) :: x
                                      real(8), intent (in) :: y
                                      res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                  end function
                                  real(4) function fmin44(x, y) result (res)
                                      real(4), intent (in) :: x
                                      real(4), intent (in) :: y
                                      res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                  end function
                                  real(8) function fmin84(x, y) result(res)
                                      real(8), intent (in) :: x
                                      real(4), intent (in) :: y
                                      res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                  end function
                                  real(8) function fmin48(x, y) result(res)
                                      real(4), intent (in) :: x
                                      real(8), intent (in) :: y
                                      res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                  end function
                              end module
                              
                              real(8) function code(c_p, c_n, t, s)
                              use fmin_fmax_functions
                                  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 87.2%

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

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

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

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

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

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

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

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

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

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

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

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

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

                                  \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
                                13. lower-neg.f6489.9

                                  \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
                              5. Applied rewrites89.9%

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

                                \[\leadsto 1 \]
                              7. Step-by-step derivation
                                1. Applied rewrites92.0%

                                  \[\leadsto 1 \]
                                2. Add Preprocessing

                                Developer Target 1: 96.3% 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);
                                }
                                
                                module fmin_fmax_functions
                                    implicit none
                                    private
                                    public fmax
                                    public fmin
                                
                                    interface fmax
                                        module procedure fmax88
                                        module procedure fmax44
                                        module procedure fmax84
                                        module procedure fmax48
                                    end interface
                                    interface fmin
                                        module procedure fmin88
                                        module procedure fmin44
                                        module procedure fmin84
                                        module procedure fmin48
                                    end interface
                                contains
                                    real(8) function fmax88(x, y) result (res)
                                        real(8), intent (in) :: x
                                        real(8), intent (in) :: y
                                        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                    end function
                                    real(4) function fmax44(x, y) result (res)
                                        real(4), intent (in) :: x
                                        real(4), intent (in) :: y
                                        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                    end function
                                    real(8) function fmax84(x, y) result(res)
                                        real(8), intent (in) :: x
                                        real(4), intent (in) :: y
                                        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                    end function
                                    real(8) function fmax48(x, y) result(res)
                                        real(4), intent (in) :: x
                                        real(8), intent (in) :: y
                                        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                    end function
                                    real(8) function fmin88(x, y) result (res)
                                        real(8), intent (in) :: x
                                        real(8), intent (in) :: y
                                        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                    end function
                                    real(4) function fmin44(x, y) result (res)
                                        real(4), intent (in) :: x
                                        real(4), intent (in) :: y
                                        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                    end function
                                    real(8) function fmin84(x, y) result(res)
                                        real(8), intent (in) :: x
                                        real(4), intent (in) :: y
                                        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                    end function
                                    real(8) function fmin48(x, y) result(res)
                                        real(4), intent (in) :: x
                                        real(8), intent (in) :: y
                                        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                    end function
                                end module
                                
                                real(8) function code(c_p, c_n, t, s)
                                use fmin_fmax_functions
                                    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 2025006 
                                (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))))