Harley's example

Percentage Accurate: 91.1% → 99.5%
Time: 55.5s
Alternatives: 7
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 7 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: 91.1% 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, 5.6× speedup?

\[\begin{array}{l} \\ e^{\mathsf{fma}\left(\mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right), s, \mathsf{fma}\left(-0.5, c\_p, \mathsf{fma}\left(\left(c\_n + c\_p\right) \cdot \mathsf{fma}\left(t \cdot t, -0.005208333333333333, 0.125\right), t, 0.5 \cdot c\_n\right)\right) \cdot t\right)} \end{array} \]
(FPCore (c_p c_n t s)
 :precision binary64
 (exp
  (fma
   (fma -0.5 c_n (* 0.5 c_p))
   s
   (*
    (fma
     -0.5
     c_p
     (fma
      (* (+ c_n c_p) (fma (* t t) -0.005208333333333333 0.125))
      t
      (* 0.5 c_n)))
    t))))
double code(double c_p, double c_n, double t, double s) {
	return exp(fma(fma(-0.5, c_n, (0.5 * c_p)), s, (fma(-0.5, c_p, fma(((c_n + c_p) * fma((t * t), -0.005208333333333333, 0.125)), t, (0.5 * c_n))) * t)));
}
function code(c_p, c_n, t, s)
	return exp(fma(fma(-0.5, c_n, Float64(0.5 * c_p)), s, Float64(fma(-0.5, c_p, fma(Float64(Float64(c_n + c_p) * fma(Float64(t * t), -0.005208333333333333, 0.125)), t, Float64(0.5 * c_n))) * t)))
end
code[c$95$p_, c$95$n_, t_, s_] := N[Exp[N[(N[(-0.5 * c$95$n + N[(0.5 * c$95$p), $MachinePrecision]), $MachinePrecision] * s + N[(N[(-0.5 * c$95$p + N[(N[(N[(c$95$n + c$95$p), $MachinePrecision] * N[(N[(t * t), $MachinePrecision] * -0.005208333333333333 + 0.125), $MachinePrecision]), $MachinePrecision] * t + N[(0.5 * c$95$n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * t), $MachinePrecision]), $MachinePrecision]], $MachinePrecision]
\begin{array}{l}

\\
e^{\mathsf{fma}\left(\mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right), s, \mathsf{fma}\left(-0.5, c\_p, \mathsf{fma}\left(\left(c\_n + c\_p\right) \cdot \mathsf{fma}\left(t \cdot t, -0.005208333333333333, 0.125\right), t, 0.5 \cdot c\_n\right)\right) \cdot t\right)}
\end{array}
Derivation
  1. Initial program 91.4%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Add Preprocessing
  3. Applied rewrites96.2%

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

    \[\leadsto e^{\color{blue}{c\_n \cdot \left(\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}\right) + \left(c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \left(\frac{1}{2} \cdot c\_n + t \cdot \left(\frac{1}{8} \cdot c\_n + \left(\frac{1}{8} \cdot c\_p + {t}^{2} \cdot \left(\frac{-1}{192} \cdot c\_n + \frac{-1}{192} \cdot c\_p\right)\right)\right)\right)\right)\right)}} \]
  5. Applied rewrites98.5%

    \[\leadsto e^{\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.005208333333333333 \cdot \left(c\_p + c\_n\right), t \cdot t, 0.125 \cdot \left(c\_p + c\_n\right)\right), t, \mathsf{fma}\left(-0.5, c\_p, 0.5 \cdot c\_n\right)\right), t, \mathsf{fma}\left(\mathsf{log1p}\left(\frac{-1}{e^{-s} + 1}\right) - \log 0.5, c\_n, \left(\log 2 - \mathsf{log1p}\left(e^{-s}\right)\right) \cdot c\_p\right)\right)}} \]
  6. Taylor expanded in s around 0

    \[\leadsto e^{s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right) + \color{blue}{t \cdot \left(\frac{-1}{2} \cdot c\_p + \left(\frac{1}{2} \cdot c\_n + t \cdot \left(\frac{-1}{192} \cdot \left({t}^{2} \cdot \left(c\_n + c\_p\right)\right) + \frac{1}{8} \cdot \left(c\_n + c\_p\right)\right)\right)\right)}} \]
  7. Applied rewrites99.8%

    \[\leadsto e^{\mathsf{fma}\left(\mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right), \color{blue}{s}, \mathsf{fma}\left(-0.5, c\_p, \mathsf{fma}\left(\left(c\_n + c\_p\right) \cdot \mathsf{fma}\left(t \cdot t, -0.005208333333333333, 0.125\right), t, 0.5 \cdot c\_n\right)\right) \cdot t\right)} \]
  8. Add Preprocessing

Alternative 2: 98.5% accurate, 7.7× speedup?

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

\\
e^{\mathsf{fma}\left(0.5, c\_p, -0.5 \cdot c\_n\right) \cdot s}
\end{array}
Derivation
  1. Initial program 91.4%

    \[\frac{{\left(\frac{1}{1 + e^{-s}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-s}}\right)}^{c\_n}}{{\left(\frac{1}{1 + e^{-t}}\right)}^{c\_p} \cdot {\left(1 - \frac{1}{1 + e^{-t}}\right)}^{c\_n}} \]
  2. Add Preprocessing
  3. Applied rewrites96.2%

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

    \[\leadsto e^{\color{blue}{c\_n \cdot \left(\log \left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right) - \log \frac{1}{2}\right) + \left(c\_p \cdot \left(\log 2 - \log \left(1 + e^{\mathsf{neg}\left(s\right)}\right)\right) + t \cdot \left(\frac{-1}{2} \cdot c\_p + \left(\frac{1}{2} \cdot c\_n + t \cdot \left(\frac{1}{8} \cdot c\_n + \left(\frac{1}{8} \cdot c\_p + {t}^{2} \cdot \left(\frac{-1}{192} \cdot c\_n + \frac{-1}{192} \cdot c\_p\right)\right)\right)\right)\right)\right)}} \]
  5. Applied rewrites98.5%

    \[\leadsto e^{\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.005208333333333333 \cdot \left(c\_p + c\_n\right), t \cdot t, 0.125 \cdot \left(c\_p + c\_n\right)\right), t, \mathsf{fma}\left(-0.5, c\_p, 0.5 \cdot c\_n\right)\right), t, \mathsf{fma}\left(\mathsf{log1p}\left(\frac{-1}{e^{-s} + 1}\right) - \log 0.5, c\_n, \left(\log 2 - \mathsf{log1p}\left(e^{-s}\right)\right) \cdot c\_p\right)\right)}} \]
  6. Taylor expanded in s around 0

    \[\leadsto e^{s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right) + \color{blue}{t \cdot \left(\frac{-1}{2} \cdot c\_p + \left(\frac{1}{2} \cdot c\_n + t \cdot \left(\frac{-1}{192} \cdot \left({t}^{2} \cdot \left(c\_n + c\_p\right)\right) + \frac{1}{8} \cdot \left(c\_n + c\_p\right)\right)\right)\right)}} \]
  7. Applied rewrites99.8%

    \[\leadsto e^{\mathsf{fma}\left(\mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right), \color{blue}{s}, \mathsf{fma}\left(-0.5, c\_p, \mathsf{fma}\left(\left(c\_n + c\_p\right) \cdot \mathsf{fma}\left(t \cdot t, -0.005208333333333333, 0.125\right), t, 0.5 \cdot c\_n\right)\right) \cdot t\right)} \]
  8. Taylor expanded in t around 0

    \[\leadsto e^{s \cdot \left(\frac{-1}{2} \cdot c\_n + \color{blue}{\frac{1}{2} \cdot c\_p}\right)} \]
  9. Step-by-step derivation
    1. Applied rewrites98.8%

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

    Alternative 3: 94.8% accurate, 15.2× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;-s \leq 500000:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.25 \cdot c\_p, c\_n, \mathsf{fma}\left(c\_n \cdot c\_n, 0.125, -0.125 \cdot c\_n\right)\right), s, \mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right)\right), s, 1\right)\\ \mathbf{else}:\\ \;\;\;\;\left(\left(\left(c\_n \cdot c\_n\right) \cdot 0.125\right) \cdot s\right) \cdot s\\ \end{array} \end{array} \]
    (FPCore (c_p c_n t s)
     :precision binary64
     (if (<= (- s) 500000.0)
       (fma
        (fma
         (fma (* -0.25 c_p) c_n (fma (* c_n c_n) 0.125 (* -0.125 c_n)))
         s
         (fma -0.5 c_n (* 0.5 c_p)))
        s
        1.0)
       (* (* (* (* c_n c_n) 0.125) s) s)))
    double code(double c_p, double c_n, double t, double s) {
    	double tmp;
    	if (-s <= 500000.0) {
    		tmp = fma(fma(fma((-0.25 * c_p), c_n, fma((c_n * c_n), 0.125, (-0.125 * c_n))), s, fma(-0.5, c_n, (0.5 * c_p))), s, 1.0);
    	} else {
    		tmp = (((c_n * c_n) * 0.125) * s) * s;
    	}
    	return tmp;
    }
    
    function code(c_p, c_n, t, s)
    	tmp = 0.0
    	if (Float64(-s) <= 500000.0)
    		tmp = fma(fma(fma(Float64(-0.25 * c_p), c_n, fma(Float64(c_n * c_n), 0.125, Float64(-0.125 * c_n))), s, fma(-0.5, c_n, Float64(0.5 * c_p))), s, 1.0);
    	else
    		tmp = Float64(Float64(Float64(Float64(c_n * c_n) * 0.125) * s) * s);
    	end
    	return tmp
    end
    
    code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[(-s), 500000.0], N[(N[(N[(N[(-0.25 * c$95$p), $MachinePrecision] * c$95$n + N[(N[(c$95$n * c$95$n), $MachinePrecision] * 0.125 + N[(-0.125 * c$95$n), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * s + N[(-0.5 * c$95$n + N[(0.5 * c$95$p), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * s + 1.0), $MachinePrecision], N[(N[(N[(N[(c$95$n * c$95$n), $MachinePrecision] * 0.125), $MachinePrecision] * s), $MachinePrecision] * s), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;-s \leq 500000:\\
    \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.25 \cdot c\_p, c\_n, \mathsf{fma}\left(c\_n \cdot c\_n, 0.125, -0.125 \cdot c\_n\right)\right), s, \mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right)\right), s, 1\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\left(\left(\left(c\_n \cdot c\_n\right) \cdot 0.125\right) \cdot s\right) \cdot s\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (neg.f64 s) < 5e5

      1. Initial program 93.1%

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

        \[\leadsto \color{blue}{\frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n} \cdot {\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_n} \cdot {\frac{1}{2}}^{c\_p}}} \]
      4. Step-by-step derivation
        1. associate-/l*N/A

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

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

          \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_n} \cdot {\frac{1}{2}}^{c\_p}} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}} \]
      5. Applied rewrites93.6%

        \[\leadsto \color{blue}{\frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{0.5}^{c\_p} \cdot {0.5}^{c\_n}} \cdot {\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}} \]
      6. Taylor expanded in s around 0

        \[\leadsto 1 + \color{blue}{s \cdot \left(\frac{-1}{2} \cdot c\_n + \left(\frac{1}{2} \cdot c\_p + s \cdot \left(\frac{-1}{4} \cdot \left(c\_n \cdot c\_p\right) + \left(\frac{-1}{8} \cdot c\_n + \left(\frac{-1}{8} \cdot c\_p + \left(\frac{1}{8} \cdot {c\_n}^{2} + \frac{1}{8} \cdot {c\_p}^{2}\right)\right)\right)\right)\right)\right)} \]
      7. Step-by-step derivation
        1. Applied rewrites94.3%

          \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.25 \cdot c\_p, c\_n, \mathsf{fma}\left(0.125, \mathsf{fma}\left(c\_p, c\_p, c\_n \cdot c\_n\right), -0.125 \cdot \left(c\_p + c\_n\right)\right)\right), s, \mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right)\right), \color{blue}{s}, 1\right) \]
        2. Taylor expanded in c_p around 0

          \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{-1}{4} \cdot c\_p, c\_n, \frac{-1}{8} \cdot c\_n + \frac{1}{8} \cdot {c\_n}^{2}\right), s, \mathsf{fma}\left(\frac{-1}{2}, c\_n, \frac{1}{2} \cdot c\_p\right)\right), s, 1\right) \]
        3. Step-by-step derivation
          1. Applied rewrites94.4%

            \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.25 \cdot c\_p, c\_n, \mathsf{fma}\left(c\_n \cdot c\_n, 0.125, -0.125 \cdot c\_n\right)\right), s, \mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right)\right), s, 1\right) \]

          if 5e5 < (neg.f64 s)

          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 t around 0

            \[\leadsto \color{blue}{\frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n} \cdot {\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_n} \cdot {\frac{1}{2}}^{c\_p}}} \]
          4. Step-by-step derivation
            1. associate-/l*N/A

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

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

              \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_n} \cdot {\frac{1}{2}}^{c\_p}} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}} \]
          5. Applied rewrites50.0%

            \[\leadsto \color{blue}{\frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{0.5}^{c\_p} \cdot {0.5}^{c\_n}} \cdot {\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}} \]
          6. Taylor expanded in s around 0

            \[\leadsto 1 + \color{blue}{s \cdot \left(\frac{-1}{2} \cdot c\_n + \left(\frac{1}{2} \cdot c\_p + s \cdot \left(\frac{-1}{4} \cdot \left(c\_n \cdot c\_p\right) + \left(\frac{-1}{8} \cdot c\_n + \left(\frac{-1}{8} \cdot c\_p + \left(\frac{1}{8} \cdot {c\_n}^{2} + \frac{1}{8} \cdot {c\_p}^{2}\right)\right)\right)\right)\right)\right)} \]
          7. Step-by-step derivation
            1. Applied rewrites1.9%

              \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.25 \cdot c\_p, c\_n, \mathsf{fma}\left(0.125, \mathsf{fma}\left(c\_p, c\_p, c\_n \cdot c\_n\right), -0.125 \cdot \left(c\_p + c\_n\right)\right)\right), s, \mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right)\right), \color{blue}{s}, 1\right) \]
            2. Taylor expanded in c_n around inf

              \[\leadsto \frac{1}{8} \cdot \left({c\_n}^{2} \cdot \color{blue}{{s}^{2}}\right) \]
            3. Step-by-step derivation
              1. Applied rewrites20.6%

                \[\leadsto \left(\left(c\_n \cdot c\_n\right) \cdot 0.125\right) \cdot \left(s \cdot \color{blue}{s}\right) \]
              2. Step-by-step derivation
                1. Applied rewrites70.7%

                  \[\leadsto \left(\left(\left(c\_n \cdot c\_n\right) \cdot 0.125\right) \cdot s\right) \cdot s \]
              3. Recombined 2 regimes into one program.
              4. Add Preprocessing

              Alternative 4: 95.1% accurate, 22.4× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;s \leq -750000000:\\ \;\;\;\;\left(\left(\left(c\_n \cdot c\_n\right) \cdot 0.125\right) \cdot s\right) \cdot s\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(-0.5, c\_n, \mathsf{fma}\left(c\_n \cdot c\_n, 0.125, -0.125 \cdot c\_n\right) \cdot s\right), s, 1\right)\\ \end{array} \end{array} \]
              (FPCore (c_p c_n t s)
               :precision binary64
               (if (<= s -750000000.0)
                 (* (* (* (* c_n c_n) 0.125) s) s)
                 (fma (fma -0.5 c_n (* (fma (* c_n c_n) 0.125 (* -0.125 c_n)) s)) s 1.0)))
              double code(double c_p, double c_n, double t, double s) {
              	double tmp;
              	if (s <= -750000000.0) {
              		tmp = (((c_n * c_n) * 0.125) * s) * s;
              	} else {
              		tmp = fma(fma(-0.5, c_n, (fma((c_n * c_n), 0.125, (-0.125 * c_n)) * s)), s, 1.0);
              	}
              	return tmp;
              }
              
              function code(c_p, c_n, t, s)
              	tmp = 0.0
              	if (s <= -750000000.0)
              		tmp = Float64(Float64(Float64(Float64(c_n * c_n) * 0.125) * s) * s);
              	else
              		tmp = fma(fma(-0.5, c_n, Float64(fma(Float64(c_n * c_n), 0.125, Float64(-0.125 * c_n)) * s)), s, 1.0);
              	end
              	return tmp
              end
              
              code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[s, -750000000.0], N[(N[(N[(N[(c$95$n * c$95$n), $MachinePrecision] * 0.125), $MachinePrecision] * s), $MachinePrecision] * s), $MachinePrecision], N[(N[(-0.5 * c$95$n + N[(N[(N[(c$95$n * c$95$n), $MachinePrecision] * 0.125 + N[(-0.125 * c$95$n), $MachinePrecision]), $MachinePrecision] * s), $MachinePrecision]), $MachinePrecision] * s + 1.0), $MachinePrecision]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              \mathbf{if}\;s \leq -750000000:\\
              \;\;\;\;\left(\left(\left(c\_n \cdot c\_n\right) \cdot 0.125\right) \cdot s\right) \cdot s\\
              
              \mathbf{else}:\\
              \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(-0.5, c\_n, \mathsf{fma}\left(c\_n \cdot c\_n, 0.125, -0.125 \cdot c\_n\right) \cdot s\right), s, 1\right)\\
              
              
              \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 t around 0

                  \[\leadsto \color{blue}{\frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n} \cdot {\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_n} \cdot {\frac{1}{2}}^{c\_p}}} \]
                4. Step-by-step derivation
                  1. associate-/l*N/A

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

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

                    \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_n} \cdot {\frac{1}{2}}^{c\_p}} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}} \]
                5. Applied rewrites50.0%

                  \[\leadsto \color{blue}{\frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{0.5}^{c\_p} \cdot {0.5}^{c\_n}} \cdot {\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}} \]
                6. Taylor expanded in s around 0

                  \[\leadsto 1 + \color{blue}{s \cdot \left(\frac{-1}{2} \cdot c\_n + \left(\frac{1}{2} \cdot c\_p + s \cdot \left(\frac{-1}{4} \cdot \left(c\_n \cdot c\_p\right) + \left(\frac{-1}{8} \cdot c\_n + \left(\frac{-1}{8} \cdot c\_p + \left(\frac{1}{8} \cdot {c\_n}^{2} + \frac{1}{8} \cdot {c\_p}^{2}\right)\right)\right)\right)\right)\right)} \]
                7. Step-by-step derivation
                  1. Applied rewrites1.9%

                    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.25 \cdot c\_p, c\_n, \mathsf{fma}\left(0.125, \mathsf{fma}\left(c\_p, c\_p, c\_n \cdot c\_n\right), -0.125 \cdot \left(c\_p + c\_n\right)\right)\right), s, \mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right)\right), \color{blue}{s}, 1\right) \]
                  2. Taylor expanded in c_n around inf

                    \[\leadsto \frac{1}{8} \cdot \left({c\_n}^{2} \cdot \color{blue}{{s}^{2}}\right) \]
                  3. Step-by-step derivation
                    1. Applied rewrites20.6%

                      \[\leadsto \left(\left(c\_n \cdot c\_n\right) \cdot 0.125\right) \cdot \left(s \cdot \color{blue}{s}\right) \]
                    2. Step-by-step derivation
                      1. Applied rewrites70.7%

                        \[\leadsto \left(\left(\left(c\_n \cdot c\_n\right) \cdot 0.125\right) \cdot s\right) \cdot s \]

                      if -7.5e8 < s

                      1. Initial program 93.1%

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

                        \[\leadsto \color{blue}{\frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n} \cdot {\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_n} \cdot {\frac{1}{2}}^{c\_p}}} \]
                      4. Step-by-step derivation
                        1. associate-/l*N/A

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

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

                          \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_n} \cdot {\frac{1}{2}}^{c\_p}} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}} \]
                      5. Applied rewrites93.6%

                        \[\leadsto \color{blue}{\frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{0.5}^{c\_p} \cdot {0.5}^{c\_n}} \cdot {\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}} \]
                      6. Taylor expanded in s around 0

                        \[\leadsto 1 + \color{blue}{s \cdot \left(\frac{-1}{2} \cdot c\_n + \left(\frac{1}{2} \cdot c\_p + s \cdot \left(\frac{-1}{4} \cdot \left(c\_n \cdot c\_p\right) + \left(\frac{-1}{8} \cdot c\_n + \left(\frac{-1}{8} \cdot c\_p + \left(\frac{1}{8} \cdot {c\_n}^{2} + \frac{1}{8} \cdot {c\_p}^{2}\right)\right)\right)\right)\right)\right)} \]
                      7. Step-by-step derivation
                        1. Applied rewrites94.3%

                          \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.25 \cdot c\_p, c\_n, \mathsf{fma}\left(0.125, \mathsf{fma}\left(c\_p, c\_p, c\_n \cdot c\_n\right), -0.125 \cdot \left(c\_p + c\_n\right)\right)\right), s, \mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right)\right), \color{blue}{s}, 1\right) \]
                        2. Taylor expanded in c_p around 0

                          \[\leadsto \mathsf{fma}\left(\frac{-1}{2} \cdot c\_n + s \cdot \left(\frac{-1}{8} \cdot c\_n + \frac{1}{8} \cdot {c\_n}^{2}\right), s, 1\right) \]
                        3. Step-by-step derivation
                          1. Applied rewrites94.4%

                            \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(-0.5, c\_n, \mathsf{fma}\left(c\_n \cdot c\_n, 0.125, -0.125 \cdot c\_n\right) \cdot s\right), s, 1\right) \]
                        4. Recombined 2 regimes into one program.
                        5. Add Preprocessing

                        Alternative 5: 95.1% accurate, 33.2× speedup?

                        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;s \leq -7.3 \cdot 10^{+21}:\\ \;\;\;\;\left(\left(\left(c\_n \cdot c\_n\right) \cdot 0.125\right) \cdot s\right) \cdot s\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right), s, 1\right)\\ \end{array} \end{array} \]
                        (FPCore (c_p c_n t s)
                         :precision binary64
                         (if (<= s -7.3e+21)
                           (* (* (* (* c_n c_n) 0.125) s) s)
                           (fma (fma -0.5 c_n (* 0.5 c_p)) s 1.0)))
                        double code(double c_p, double c_n, double t, double s) {
                        	double tmp;
                        	if (s <= -7.3e+21) {
                        		tmp = (((c_n * c_n) * 0.125) * s) * s;
                        	} else {
                        		tmp = fma(fma(-0.5, c_n, (0.5 * c_p)), s, 1.0);
                        	}
                        	return tmp;
                        }
                        
                        function code(c_p, c_n, t, s)
                        	tmp = 0.0
                        	if (s <= -7.3e+21)
                        		tmp = Float64(Float64(Float64(Float64(c_n * c_n) * 0.125) * s) * s);
                        	else
                        		tmp = fma(fma(-0.5, c_n, Float64(0.5 * c_p)), s, 1.0);
                        	end
                        	return tmp
                        end
                        
                        code[c$95$p_, c$95$n_, t_, s_] := If[LessEqual[s, -7.3e+21], N[(N[(N[(N[(c$95$n * c$95$n), $MachinePrecision] * 0.125), $MachinePrecision] * s), $MachinePrecision] * s), $MachinePrecision], N[(N[(-0.5 * c$95$n + N[(0.5 * c$95$p), $MachinePrecision]), $MachinePrecision] * s + 1.0), $MachinePrecision]]
                        
                        \begin{array}{l}
                        
                        \\
                        \begin{array}{l}
                        \mathbf{if}\;s \leq -7.3 \cdot 10^{+21}:\\
                        \;\;\;\;\left(\left(\left(c\_n \cdot c\_n\right) \cdot 0.125\right) \cdot s\right) \cdot s\\
                        
                        \mathbf{else}:\\
                        \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right), s, 1\right)\\
                        
                        
                        \end{array}
                        \end{array}
                        
                        Derivation
                        1. Split input into 2 regimes
                        2. if s < -7.3e21

                          1. Initial program 44.4%

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

                            \[\leadsto \color{blue}{\frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n} \cdot {\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_n} \cdot {\frac{1}{2}}^{c\_p}}} \]
                          4. Step-by-step derivation
                            1. associate-/l*N/A

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

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

                              \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_n} \cdot {\frac{1}{2}}^{c\_p}} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}} \]
                          5. Applied rewrites44.4%

                            \[\leadsto \color{blue}{\frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{0.5}^{c\_p} \cdot {0.5}^{c\_n}} \cdot {\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}} \]
                          6. Taylor expanded in s around 0

                            \[\leadsto 1 + \color{blue}{s \cdot \left(\frac{-1}{2} \cdot c\_n + \left(\frac{1}{2} \cdot c\_p + s \cdot \left(\frac{-1}{4} \cdot \left(c\_n \cdot c\_p\right) + \left(\frac{-1}{8} \cdot c\_n + \left(\frac{-1}{8} \cdot c\_p + \left(\frac{1}{8} \cdot {c\_n}^{2} + \frac{1}{8} \cdot {c\_p}^{2}\right)\right)\right)\right)\right)\right)} \]
                          7. Step-by-step derivation
                            1. Applied rewrites1.8%

                              \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(-0.25 \cdot c\_p, c\_n, \mathsf{fma}\left(0.125, \mathsf{fma}\left(c\_p, c\_p, c\_n \cdot c\_n\right), -0.125 \cdot \left(c\_p + c\_n\right)\right)\right), s, \mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right)\right), \color{blue}{s}, 1\right) \]
                            2. Taylor expanded in c_n around inf

                              \[\leadsto \frac{1}{8} \cdot \left({c\_n}^{2} \cdot \color{blue}{{s}^{2}}\right) \]
                            3. Step-by-step derivation
                              1. Applied rewrites22.6%

                                \[\leadsto \left(\left(c\_n \cdot c\_n\right) \cdot 0.125\right) \cdot \left(s \cdot \color{blue}{s}\right) \]
                              2. Step-by-step derivation
                                1. Applied rewrites78.3%

                                  \[\leadsto \left(\left(\left(c\_n \cdot c\_n\right) \cdot 0.125\right) \cdot s\right) \cdot s \]

                                if -7.3e21 < s

                                1. Initial program 93.2%

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

                                  \[\leadsto \color{blue}{\frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n} \cdot {\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_n} \cdot {\frac{1}{2}}^{c\_p}}} \]
                                4. Step-by-step derivation
                                  1. associate-/l*N/A

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

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

                                    \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_n} \cdot {\frac{1}{2}}^{c\_p}} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}} \]
                                5. Applied rewrites93.7%

                                  \[\leadsto \color{blue}{\frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{0.5}^{c\_p} \cdot {0.5}^{c\_n}} \cdot {\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}} \]
                                6. Taylor expanded in s around 0

                                  \[\leadsto 1 + \color{blue}{s \cdot \left(\frac{-1}{2} \cdot c\_n + \frac{1}{2} \cdot c\_p\right)} \]
                                7. Step-by-step derivation
                                  1. Applied rewrites94.0%

                                    \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(-0.5, c\_n, 0.5 \cdot c\_p\right), \color{blue}{s}, 1\right) \]
                                8. Recombined 2 regimes into one program.
                                9. Add Preprocessing

                                Alternative 6: 94.1% accurate, 74.7× speedup?

                                \[\begin{array}{l} \\ \mathsf{fma}\left(s \cdot c\_n, -0.5, 1\right) \end{array} \]
                                (FPCore (c_p c_n t s) :precision binary64 (fma (* s c_n) -0.5 1.0))
                                double code(double c_p, double c_n, double t, double s) {
                                	return fma((s * c_n), -0.5, 1.0);
                                }
                                
                                function code(c_p, c_n, t, s)
                                	return fma(Float64(s * c_n), -0.5, 1.0)
                                end
                                
                                code[c$95$p_, c$95$n_, t_, s_] := N[(N[(s * c$95$n), $MachinePrecision] * -0.5 + 1.0), $MachinePrecision]
                                
                                \begin{array}{l}
                                
                                \\
                                \mathsf{fma}\left(s \cdot c\_n, -0.5, 1\right)
                                \end{array}
                                
                                Derivation
                                1. Initial program 91.4%

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

                                  \[\leadsto \color{blue}{\frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n} \cdot {\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_n} \cdot {\frac{1}{2}}^{c\_p}}} \]
                                4. Step-by-step derivation
                                  1. associate-/l*N/A

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

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

                                    \[\leadsto \color{blue}{\frac{{\left(\frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_p}}{{\frac{1}{2}}^{c\_n} \cdot {\frac{1}{2}}^{c\_p}} \cdot {\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}} \]
                                5. Applied rewrites91.9%

                                  \[\leadsto \color{blue}{\frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{0.5}^{c\_p} \cdot {0.5}^{c\_n}} \cdot {\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}} \]
                                6. Taylor expanded in c_p around 0

                                  \[\leadsto \frac{{\left(1 - \frac{1}{1 + e^{\mathsf{neg}\left(s\right)}}\right)}^{c\_n}}{\color{blue}{{\frac{1}{2}}^{c\_n}}} \]
                                7. Step-by-step derivation
                                  1. Applied rewrites91.5%

                                    \[\leadsto \frac{{\left(1 - \frac{1}{e^{-s} + 1}\right)}^{c\_n}}{\color{blue}{{0.5}^{c\_n}}} \]
                                  2. Taylor expanded in s around 0

                                    \[\leadsto 1 + \frac{-1}{2} \cdot \color{blue}{\left(c\_n \cdot s\right)} \]
                                  3. Step-by-step derivation
                                    1. Applied rewrites90.8%

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

                                    Alternative 7: 94.2% 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 91.4%

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

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

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

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

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

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

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

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

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

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

                                        \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{\color{blue}{e^{\mathsf{neg}\left(t\right)}} + 1}\right)}^{c\_p}} \]
                                      15. lower-neg.f6490.7

                                        \[\leadsto \frac{{\left(\frac{1}{e^{-s} + 1}\right)}^{c\_p}}{{\left(\frac{1}{e^{\color{blue}{-t}} + 1}\right)}^{c\_p}} \]
                                    5. Applied rewrites90.7%

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

                                      \[\leadsto 1 \]
                                    7. Step-by-step derivation
                                      1. Applied rewrites90.7%

                                        \[\leadsto 1 \]
                                      2. Add Preprocessing

                                      Developer Target 1: 96.5% 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 2024296 
                                      (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))))