Hyperbolic secant

Percentage Accurate: 100.0% → 100.0%
Time: 8.5s
Alternatives: 11
Speedup: 1.9×

Specification

?
\[\begin{array}{l} \\ \frac{2}{e^{x} + e^{-x}} \end{array} \]
(FPCore (x) :precision binary64 (/ 2.0 (+ (exp x) (exp (- x)))))
double code(double x) {
	return 2.0 / (exp(x) + exp(-x));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 2.0d0 / (exp(x) + exp(-x))
end function
public static double code(double x) {
	return 2.0 / (Math.exp(x) + Math.exp(-x));
}
def code(x):
	return 2.0 / (math.exp(x) + math.exp(-x))
function code(x)
	return Float64(2.0 / Float64(exp(x) + exp(Float64(-x))))
end
function tmp = code(x)
	tmp = 2.0 / (exp(x) + exp(-x));
end
code[x_] := N[(2.0 / N[(N[Exp[x], $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{2}{e^{x} + e^{-x}}
\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 11 alternatives:

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

Initial Program: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{2}{e^{x} + e^{-x}} \end{array} \]
(FPCore (x) :precision binary64 (/ 2.0 (+ (exp x) (exp (- x)))))
double code(double x) {
	return 2.0 / (exp(x) + exp(-x));
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 2.0d0 / (exp(x) + exp(-x))
end function
public static double code(double x) {
	return 2.0 / (Math.exp(x) + Math.exp(-x));
}
def code(x):
	return 2.0 / (math.exp(x) + math.exp(-x))
function code(x)
	return Float64(2.0 / Float64(exp(x) + exp(Float64(-x))))
end
function tmp = code(x)
	tmp = 2.0 / (exp(x) + exp(-x));
end
code[x_] := N[(2.0 / N[(N[Exp[x], $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{2}{e^{x} + e^{-x}}
\end{array}

Alternative 1: 100.0% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \frac{1}{\cosh x} \end{array} \]
(FPCore (x) :precision binary64 (/ 1.0 (cosh x)))
double code(double x) {
	return 1.0 / cosh(x);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 1.0d0 / cosh(x)
end function
public static double code(double x) {
	return 1.0 / Math.cosh(x);
}
def code(x):
	return 1.0 / math.cosh(x)
function code(x)
	return Float64(1.0 / cosh(x))
end
function tmp = code(x)
	tmp = 1.0 / cosh(x);
end
code[x_] := N[(1.0 / N[Cosh[x], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{\cosh x}
\end{array}
Derivation
  1. Initial program 100.0%

    \[\frac{2}{e^{x} + e^{-x}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. cosh-undefN/A

      \[\leadsto \frac{2}{\color{blue}{2 \cdot \cosh x}} \]
    2. associate-/r*N/A

      \[\leadsto \color{blue}{\frac{\frac{2}{2}}{\cosh x}} \]
    3. metadata-evalN/A

      \[\leadsto \frac{\color{blue}{1}}{\cosh x} \]
    4. lower-/.f64N/A

      \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
    5. lower-cosh.f64100.0

      \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
  4. Applied rewrites100.0%

    \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
  5. Add Preprocessing

Alternative 2: 91.9% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{2}{e^{x} + e^{-x}} \leq 0:\\ \;\;\;\;\frac{720}{\left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot -0.08472222222222223, 0.20833333333333334\right), -0.5\right), 1\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= (/ 2.0 (+ (exp x) (exp (- x)))) 0.0)
   (/ 720.0 (* (* x x) (* x (* x (* x x)))))
   (fma
    (* x x)
    (fma (* x x) (fma x (* x -0.08472222222222223) 0.20833333333333334) -0.5)
    1.0)))
double code(double x) {
	double tmp;
	if ((2.0 / (exp(x) + exp(-x))) <= 0.0) {
		tmp = 720.0 / ((x * x) * (x * (x * (x * x))));
	} else {
		tmp = fma((x * x), fma((x * x), fma(x, (x * -0.08472222222222223), 0.20833333333333334), -0.5), 1.0);
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (Float64(2.0 / Float64(exp(x) + exp(Float64(-x)))) <= 0.0)
		tmp = Float64(720.0 / Float64(Float64(x * x) * Float64(x * Float64(x * Float64(x * x)))));
	else
		tmp = fma(Float64(x * x), fma(Float64(x * x), fma(x, Float64(x * -0.08472222222222223), 0.20833333333333334), -0.5), 1.0);
	end
	return tmp
end
code[x_] := If[LessEqual[N[(2.0 / N[(N[Exp[x], $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 0.0], N[(720.0 / N[(N[(x * x), $MachinePrecision] * N[(x * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * N[(x * N[(x * -0.08472222222222223), $MachinePrecision] + 0.20833333333333334), $MachinePrecision] + -0.5), $MachinePrecision] + 1.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{2}{e^{x} + e^{-x}} \leq 0:\\
\;\;\;\;\frac{720}{\left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)}\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot -0.08472222222222223, 0.20833333333333334\right), -0.5\right), 1\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 #s(literal 2 binary64) (+.f64 (exp.f64 x) (exp.f64 (neg.f64 x)))) < 0.0

    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \frac{2}{\color{blue}{2 + {x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)}} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \frac{2}{\color{blue}{{x}^{2} \cdot \left(1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right) + 2}} \]
      2. unpow2N/A

        \[\leadsto \frac{2}{\color{blue}{\left(x \cdot x\right)} \cdot \left(1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right) + 2} \]
      3. associate-*l*N/A

        \[\leadsto \frac{2}{\color{blue}{x \cdot \left(x \cdot \left(1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)\right)} + 2} \]
      4. lower-fma.f64N/A

        \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left(x, x \cdot \left(1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right), 2\right)}} \]
    5. Applied rewrites83.1%

      \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(x \cdot x, x \cdot \mathsf{fma}\left(x, x \cdot 0.002777777777777778, 0.08333333333333333\right), x\right), 2\right)}} \]
    6. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{720}{{x}^{6}}} \]
    7. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{720}{{x}^{6}}} \]
      2. metadata-evalN/A

        \[\leadsto \frac{720}{{x}^{\color{blue}{\left(5 + 1\right)}}} \]
      3. pow-plusN/A

        \[\leadsto \frac{720}{\color{blue}{{x}^{5} \cdot x}} \]
      4. metadata-evalN/A

        \[\leadsto \frac{720}{{x}^{\color{blue}{\left(4 + 1\right)}} \cdot x} \]
      5. pow-plusN/A

        \[\leadsto \frac{720}{\color{blue}{\left({x}^{4} \cdot x\right)} \cdot x} \]
      6. associate-*r*N/A

        \[\leadsto \frac{720}{\color{blue}{{x}^{4} \cdot \left(x \cdot x\right)}} \]
      7. unpow2N/A

        \[\leadsto \frac{720}{{x}^{4} \cdot \color{blue}{{x}^{2}}} \]
      8. *-commutativeN/A

        \[\leadsto \frac{720}{\color{blue}{{x}^{2} \cdot {x}^{4}}} \]
      9. lower-*.f64N/A

        \[\leadsto \frac{720}{\color{blue}{{x}^{2} \cdot {x}^{4}}} \]
      10. unpow2N/A

        \[\leadsto \frac{720}{\color{blue}{\left(x \cdot x\right)} \cdot {x}^{4}} \]
      11. lower-*.f64N/A

        \[\leadsto \frac{720}{\color{blue}{\left(x \cdot x\right)} \cdot {x}^{4}} \]
      12. metadata-evalN/A

        \[\leadsto \frac{720}{\left(x \cdot x\right) \cdot {x}^{\color{blue}{\left(2 \cdot 2\right)}}} \]
      13. pow-sqrN/A

        \[\leadsto \frac{720}{\left(x \cdot x\right) \cdot \color{blue}{\left({x}^{2} \cdot {x}^{2}\right)}} \]
      14. unpow2N/A

        \[\leadsto \frac{720}{\left(x \cdot x\right) \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {x}^{2}\right)} \]
      15. associate-*l*N/A

        \[\leadsto \frac{720}{\left(x \cdot x\right) \cdot \color{blue}{\left(x \cdot \left(x \cdot {x}^{2}\right)\right)}} \]
      16. unpow2N/A

        \[\leadsto \frac{720}{\left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right)\right)} \]
      17. cube-multN/A

        \[\leadsto \frac{720}{\left(x \cdot x\right) \cdot \left(x \cdot \color{blue}{{x}^{3}}\right)} \]
      18. lower-*.f64N/A

        \[\leadsto \frac{720}{\left(x \cdot x\right) \cdot \color{blue}{\left(x \cdot {x}^{3}\right)}} \]
      19. cube-multN/A

        \[\leadsto \frac{720}{\left(x \cdot x\right) \cdot \left(x \cdot \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)}\right)} \]
      20. unpow2N/A

        \[\leadsto \frac{720}{\left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \color{blue}{{x}^{2}}\right)\right)} \]
      21. lower-*.f64N/A

        \[\leadsto \frac{720}{\left(x \cdot x\right) \cdot \left(x \cdot \color{blue}{\left(x \cdot {x}^{2}\right)}\right)} \]
      22. unpow2N/A

        \[\leadsto \frac{720}{\left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right)\right)} \]
      23. lower-*.f6483.8

        \[\leadsto \frac{720}{\left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right)\right)} \]
    8. Applied rewrites83.8%

      \[\leadsto \color{blue}{\frac{720}{\left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)}} \]

    if 0.0 < (/.f64 #s(literal 2 binary64) (+.f64 (exp.f64 x) (exp.f64 (neg.f64 x))))

    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{1 + {x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{5}{24} + \frac{-61}{720} \cdot {x}^{2}\right) - \frac{1}{2}\right)} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \color{blue}{{x}^{2} \cdot \left({x}^{2} \cdot \left(\frac{5}{24} + \frac{-61}{720} \cdot {x}^{2}\right) - \frac{1}{2}\right) + 1} \]
      2. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{2}, {x}^{2} \cdot \left(\frac{5}{24} + \frac{-61}{720} \cdot {x}^{2}\right) - \frac{1}{2}, 1\right)} \]
      3. unpow2N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{x \cdot x}, {x}^{2} \cdot \left(\frac{5}{24} + \frac{-61}{720} \cdot {x}^{2}\right) - \frac{1}{2}, 1\right) \]
      4. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{x \cdot x}, {x}^{2} \cdot \left(\frac{5}{24} + \frac{-61}{720} \cdot {x}^{2}\right) - \frac{1}{2}, 1\right) \]
      5. sub-negN/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{{x}^{2} \cdot \left(\frac{5}{24} + \frac{-61}{720} \cdot {x}^{2}\right) + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}, 1\right) \]
      6. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, {x}^{2} \cdot \left(\frac{5}{24} + \frac{-61}{720} \cdot {x}^{2}\right) + \color{blue}{\frac{-1}{2}}, 1\right) \]
      7. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{5}{24} + \frac{-61}{720} \cdot {x}^{2}, \frac{-1}{2}\right)}, 1\right) \]
      8. unpow2N/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{5}{24} + \frac{-61}{720} \cdot {x}^{2}, \frac{-1}{2}\right), 1\right) \]
      9. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{5}{24} + \frac{-61}{720} \cdot {x}^{2}, \frac{-1}{2}\right), 1\right) \]
      10. +-commutativeN/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{-61}{720} \cdot {x}^{2} + \frac{5}{24}}, \frac{-1}{2}\right), 1\right) \]
      11. *-commutativeN/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{{x}^{2} \cdot \frac{-61}{720}} + \frac{5}{24}, \frac{-1}{2}\right), 1\right) \]
      12. unpow2N/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\left(x \cdot x\right)} \cdot \frac{-61}{720} + \frac{5}{24}, \frac{-1}{2}\right), 1\right) \]
      13. associate-*l*N/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{x \cdot \left(x \cdot \frac{-61}{720}\right)} + \frac{5}{24}, \frac{-1}{2}\right), 1\right) \]
      14. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left(x, x \cdot \frac{-61}{720}, \frac{5}{24}\right)}, \frac{-1}{2}\right), 1\right) \]
      15. lower-*.f6499.7

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot -0.08472222222222223}, 0.20833333333333334\right), -0.5\right), 1\right) \]
    5. Applied rewrites99.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot -0.08472222222222223, 0.20833333333333334\right), -0.5\right), 1\right)} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 87.6% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{x} + e^{-x} \leq 4:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.20833333333333334, -0.5\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\left(x \cdot x\right) \cdot \mathsf{fma}\left(0.041666666666666664, x \cdot x, 0.5\right)}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= (+ (exp x) (exp (- x))) 4.0)
   (fma (* x x) (fma x (* x 0.20833333333333334) -0.5) 1.0)
   (/ 1.0 (* (* x x) (fma 0.041666666666666664 (* x x) 0.5)))))
double code(double x) {
	double tmp;
	if ((exp(x) + exp(-x)) <= 4.0) {
		tmp = fma((x * x), fma(x, (x * 0.20833333333333334), -0.5), 1.0);
	} else {
		tmp = 1.0 / ((x * x) * fma(0.041666666666666664, (x * x), 0.5));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (Float64(exp(x) + exp(Float64(-x))) <= 4.0)
		tmp = fma(Float64(x * x), fma(x, Float64(x * 0.20833333333333334), -0.5), 1.0);
	else
		tmp = Float64(1.0 / Float64(Float64(x * x) * fma(0.041666666666666664, Float64(x * x), 0.5)));
	end
	return tmp
end
code[x_] := If[LessEqual[N[(N[Exp[x], $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision], 4.0], N[(N[(x * x), $MachinePrecision] * N[(x * N[(x * 0.20833333333333334), $MachinePrecision] + -0.5), $MachinePrecision] + 1.0), $MachinePrecision], N[(1.0 / N[(N[(x * x), $MachinePrecision] * N[(0.041666666666666664 * N[(x * x), $MachinePrecision] + 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;e^{x} + e^{-x} \leq 4:\\
\;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.20833333333333334, -0.5\right), 1\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{\left(x \cdot x\right) \cdot \mathsf{fma}\left(0.041666666666666664, x \cdot x, 0.5\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (exp.f64 x) (exp.f64 (neg.f64 x))) < 4

    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cosh-undefN/A

        \[\leadsto \frac{2}{\color{blue}{2 \cdot \cosh x}} \]
      2. associate-/r*N/A

        \[\leadsto \color{blue}{\frac{\frac{2}{2}}{\cosh x}} \]
      3. metadata-evalN/A

        \[\leadsto \frac{\color{blue}{1}}{\cosh x} \]
      4. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
      5. lower-cosh.f64100.0

        \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
    4. Applied rewrites100.0%

      \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
    5. Taylor expanded in x around 0

      \[\leadsto \color{blue}{1 + {x}^{2} \cdot \left(\frac{5}{24} \cdot {x}^{2} - \frac{1}{2}\right)} \]
    6. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \color{blue}{{x}^{2} \cdot \left(\frac{5}{24} \cdot {x}^{2} - \frac{1}{2}\right) + 1} \]
      2. lower-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{5}{24} \cdot {x}^{2} - \frac{1}{2}, 1\right)} \]
      3. unpow2N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{5}{24} \cdot {x}^{2} - \frac{1}{2}, 1\right) \]
      4. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{5}{24} \cdot {x}^{2} - \frac{1}{2}, 1\right) \]
      5. sub-negN/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{5}{24} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}, 1\right) \]
      6. *-commutativeN/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{{x}^{2} \cdot \frac{5}{24}} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right), 1\right) \]
      7. unpow2N/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{\left(x \cdot x\right)} \cdot \frac{5}{24} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right), 1\right) \]
      8. associate-*l*N/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{x \cdot \left(x \cdot \frac{5}{24}\right)} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right), 1\right) \]
      9. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, x \cdot \left(x \cdot \frac{5}{24}\right) + \color{blue}{\frac{-1}{2}}, 1\right) \]
      10. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left(x, x \cdot \frac{5}{24}, \frac{-1}{2}\right)}, 1\right) \]
      11. lower-*.f6499.6

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot 0.20833333333333334}, -0.5\right), 1\right) \]
    7. Applied rewrites99.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.20833333333333334, -0.5\right), 1\right)} \]

    if 4 < (+.f64 (exp.f64 x) (exp.f64 (neg.f64 x)))

    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cosh-undefN/A

        \[\leadsto \frac{2}{\color{blue}{2 \cdot \cosh x}} \]
      2. associate-/r*N/A

        \[\leadsto \color{blue}{\frac{\frac{2}{2}}{\cosh x}} \]
      3. metadata-evalN/A

        \[\leadsto \frac{\color{blue}{1}}{\cosh x} \]
      4. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
      5. lower-cosh.f64100.0

        \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
    4. Applied rewrites100.0%

      \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
    5. Taylor expanded in x around 0

      \[\leadsto \frac{1}{\color{blue}{1 + {x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)}} \]
    6. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \frac{1}{\color{blue}{{x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right) + 1}} \]
      2. lower-fma.f64N/A

        \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)}} \]
      3. unpow2N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)} \]
      5. +-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{{x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right) + \frac{1}{2}}, 1\right)} \]
      6. lower-fma.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right)}, 1\right)} \]
      7. unpow2N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right), 1\right)} \]
      8. lower-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right), 1\right)} \]
      9. +-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{1}{720} \cdot {x}^{2} + \frac{1}{24}}, \frac{1}{2}\right), 1\right)} \]
      10. *-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{{x}^{2} \cdot \frac{1}{720}} + \frac{1}{24}, \frac{1}{2}\right), 1\right)} \]
      11. lower-fma.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{720}, \frac{1}{24}\right)}, \frac{1}{2}\right), 1\right)} \]
      12. unpow2N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{720}, \frac{1}{24}\right), \frac{1}{2}\right), 1\right)} \]
      13. lower-*.f6483.1

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, 0.001388888888888889, 0.041666666666666664\right), 0.5\right), 1\right)} \]
    7. Applied rewrites83.1%

      \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, 0.041666666666666664\right), 0.5\right), 1\right)}} \]
    8. Taylor expanded in x around 0

      \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{1}{24}}, \frac{1}{2}\right), 1\right)} \]
    9. Step-by-step derivation
      1. Applied rewrites77.0%

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{0.041666666666666664}, 0.5\right), 1\right)} \]
      2. Taylor expanded in x around inf

        \[\leadsto \frac{1}{\color{blue}{{x}^{4} \cdot \left(\frac{1}{24} + \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)}} \]
      3. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \frac{1}{{x}^{4} \cdot \color{blue}{\left(\frac{1}{2} \cdot \frac{1}{{x}^{2}} + \frac{1}{24}\right)}} \]
        2. distribute-lft-inN/A

          \[\leadsto \frac{1}{\color{blue}{{x}^{4} \cdot \left(\frac{1}{2} \cdot \frac{1}{{x}^{2}}\right) + {x}^{4} \cdot \frac{1}{24}}} \]
        3. associate-*r/N/A

          \[\leadsto \frac{1}{{x}^{4} \cdot \color{blue}{\frac{\frac{1}{2} \cdot 1}{{x}^{2}}} + {x}^{4} \cdot \frac{1}{24}} \]
        4. metadata-evalN/A

          \[\leadsto \frac{1}{{x}^{4} \cdot \frac{\color{blue}{\frac{1}{2}}}{{x}^{2}} + {x}^{4} \cdot \frac{1}{24}} \]
        5. associate-*r/N/A

          \[\leadsto \frac{1}{\color{blue}{\frac{{x}^{4} \cdot \frac{1}{2}}{{x}^{2}}} + {x}^{4} \cdot \frac{1}{24}} \]
        6. *-commutativeN/A

          \[\leadsto \frac{1}{\frac{\color{blue}{\frac{1}{2} \cdot {x}^{4}}}{{x}^{2}} + {x}^{4} \cdot \frac{1}{24}} \]
        7. associate-/l*N/A

          \[\leadsto \frac{1}{\color{blue}{\frac{1}{2} \cdot \frac{{x}^{4}}{{x}^{2}}} + {x}^{4} \cdot \frac{1}{24}} \]
        8. metadata-evalN/A

          \[\leadsto \frac{1}{\frac{1}{2} \cdot \frac{{x}^{\color{blue}{\left(2 \cdot 2\right)}}}{{x}^{2}} + {x}^{4} \cdot \frac{1}{24}} \]
        9. pow-sqrN/A

          \[\leadsto \frac{1}{\frac{1}{2} \cdot \frac{\color{blue}{{x}^{2} \cdot {x}^{2}}}{{x}^{2}} + {x}^{4} \cdot \frac{1}{24}} \]
        10. associate-/l*N/A

          \[\leadsto \frac{1}{\frac{1}{2} \cdot \color{blue}{\left({x}^{2} \cdot \frac{{x}^{2}}{{x}^{2}}\right)} + {x}^{4} \cdot \frac{1}{24}} \]
        11. *-rgt-identityN/A

          \[\leadsto \frac{1}{\frac{1}{2} \cdot \left({x}^{2} \cdot \frac{\color{blue}{{x}^{2} \cdot 1}}{{x}^{2}}\right) + {x}^{4} \cdot \frac{1}{24}} \]
        12. associate-*r/N/A

          \[\leadsto \frac{1}{\frac{1}{2} \cdot \left({x}^{2} \cdot \color{blue}{\left({x}^{2} \cdot \frac{1}{{x}^{2}}\right)}\right) + {x}^{4} \cdot \frac{1}{24}} \]
        13. rgt-mult-inverseN/A

          \[\leadsto \frac{1}{\frac{1}{2} \cdot \left({x}^{2} \cdot \color{blue}{1}\right) + {x}^{4} \cdot \frac{1}{24}} \]
        14. *-commutativeN/A

          \[\leadsto \frac{1}{\frac{1}{2} \cdot \color{blue}{\left(1 \cdot {x}^{2}\right)} + {x}^{4} \cdot \frac{1}{24}} \]
        15. *-lft-identityN/A

          \[\leadsto \frac{1}{\frac{1}{2} \cdot \color{blue}{{x}^{2}} + {x}^{4} \cdot \frac{1}{24}} \]
        16. *-commutativeN/A

          \[\leadsto \frac{1}{\frac{1}{2} \cdot {x}^{2} + \color{blue}{\frac{1}{24} \cdot {x}^{4}}} \]
        17. metadata-evalN/A

          \[\leadsto \frac{1}{\frac{1}{2} \cdot {x}^{2} + \frac{1}{24} \cdot {x}^{\color{blue}{\left(2 \cdot 2\right)}}} \]
        18. pow-sqrN/A

          \[\leadsto \frac{1}{\frac{1}{2} \cdot {x}^{2} + \frac{1}{24} \cdot \color{blue}{\left({x}^{2} \cdot {x}^{2}\right)}} \]
        19. associate-*l*N/A

          \[\leadsto \frac{1}{\frac{1}{2} \cdot {x}^{2} + \color{blue}{\left(\frac{1}{24} \cdot {x}^{2}\right) \cdot {x}^{2}}} \]
      4. Applied rewrites77.0%

        \[\leadsto \frac{1}{\color{blue}{\left(x \cdot x\right) \cdot \mathsf{fma}\left(0.041666666666666664, x \cdot x, 0.5\right)}} \]
    10. Recombined 2 regimes into one program.
    11. Add Preprocessing

    Alternative 4: 87.7% accurate, 0.9× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{x} + e^{-x} \leq 4:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.20833333333333334, -0.5\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{24}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= (+ (exp x) (exp (- x))) 4.0)
       (fma (* x x) (fma x (* x 0.20833333333333334) -0.5) 1.0)
       (/ 24.0 (* x (* x (* x x))))))
    double code(double x) {
    	double tmp;
    	if ((exp(x) + exp(-x)) <= 4.0) {
    		tmp = fma((x * x), fma(x, (x * 0.20833333333333334), -0.5), 1.0);
    	} else {
    		tmp = 24.0 / (x * (x * (x * x)));
    	}
    	return tmp;
    }
    
    function code(x)
    	tmp = 0.0
    	if (Float64(exp(x) + exp(Float64(-x))) <= 4.0)
    		tmp = fma(Float64(x * x), fma(x, Float64(x * 0.20833333333333334), -0.5), 1.0);
    	else
    		tmp = Float64(24.0 / Float64(x * Float64(x * Float64(x * x))));
    	end
    	return tmp
    end
    
    code[x_] := If[LessEqual[N[(N[Exp[x], $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision], 4.0], N[(N[(x * x), $MachinePrecision] * N[(x * N[(x * 0.20833333333333334), $MachinePrecision] + -0.5), $MachinePrecision] + 1.0), $MachinePrecision], N[(24.0 / N[(x * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;e^{x} + e^{-x} \leq 4:\\
    \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.20833333333333334, -0.5\right), 1\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\frac{24}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (+.f64 (exp.f64 x) (exp.f64 (neg.f64 x))) < 4

      1. Initial program 100.0%

        \[\frac{2}{e^{x} + e^{-x}} \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. cosh-undefN/A

          \[\leadsto \frac{2}{\color{blue}{2 \cdot \cosh x}} \]
        2. associate-/r*N/A

          \[\leadsto \color{blue}{\frac{\frac{2}{2}}{\cosh x}} \]
        3. metadata-evalN/A

          \[\leadsto \frac{\color{blue}{1}}{\cosh x} \]
        4. lower-/.f64N/A

          \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
        5. lower-cosh.f64100.0

          \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
      4. Applied rewrites100.0%

        \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
      5. Taylor expanded in x around 0

        \[\leadsto \color{blue}{1 + {x}^{2} \cdot \left(\frac{5}{24} \cdot {x}^{2} - \frac{1}{2}\right)} \]
      6. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \color{blue}{{x}^{2} \cdot \left(\frac{5}{24} \cdot {x}^{2} - \frac{1}{2}\right) + 1} \]
        2. lower-fma.f64N/A

          \[\leadsto \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{5}{24} \cdot {x}^{2} - \frac{1}{2}, 1\right)} \]
        3. unpow2N/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{5}{24} \cdot {x}^{2} - \frac{1}{2}, 1\right) \]
        4. lower-*.f64N/A

          \[\leadsto \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{5}{24} \cdot {x}^{2} - \frac{1}{2}, 1\right) \]
        5. sub-negN/A

          \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{5}{24} \cdot {x}^{2} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right)}, 1\right) \]
        6. *-commutativeN/A

          \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{{x}^{2} \cdot \frac{5}{24}} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right), 1\right) \]
        7. unpow2N/A

          \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{\left(x \cdot x\right)} \cdot \frac{5}{24} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right), 1\right) \]
        8. associate-*l*N/A

          \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{x \cdot \left(x \cdot \frac{5}{24}\right)} + \left(\mathsf{neg}\left(\frac{1}{2}\right)\right), 1\right) \]
        9. metadata-evalN/A

          \[\leadsto \mathsf{fma}\left(x \cdot x, x \cdot \left(x \cdot \frac{5}{24}\right) + \color{blue}{\frac{-1}{2}}, 1\right) \]
        10. lower-fma.f64N/A

          \[\leadsto \mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left(x, x \cdot \frac{5}{24}, \frac{-1}{2}\right)}, 1\right) \]
        11. lower-*.f6499.6

          \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot 0.20833333333333334}, -0.5\right), 1\right) \]
      7. Applied rewrites99.6%

        \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.20833333333333334, -0.5\right), 1\right)} \]

      if 4 < (+.f64 (exp.f64 x) (exp.f64 (neg.f64 x)))

      1. Initial program 100.0%

        \[\frac{2}{e^{x} + e^{-x}} \]
      2. Add Preprocessing
      3. Taylor expanded in x around 0

        \[\leadsto \frac{2}{\color{blue}{2 + {x}^{2} \cdot \left(1 + \frac{1}{12} \cdot {x}^{2}\right)}} \]
      4. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \frac{2}{\color{blue}{{x}^{2} \cdot \left(1 + \frac{1}{12} \cdot {x}^{2}\right) + 2}} \]
        2. unpow2N/A

          \[\leadsto \frac{2}{\color{blue}{\left(x \cdot x\right)} \cdot \left(1 + \frac{1}{12} \cdot {x}^{2}\right) + 2} \]
        3. associate-*l*N/A

          \[\leadsto \frac{2}{\color{blue}{x \cdot \left(x \cdot \left(1 + \frac{1}{12} \cdot {x}^{2}\right)\right)} + 2} \]
        4. lower-fma.f64N/A

          \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left(x, x \cdot \left(1 + \frac{1}{12} \cdot {x}^{2}\right), 2\right)}} \]
        5. +-commutativeN/A

          \[\leadsto \frac{2}{\mathsf{fma}\left(x, x \cdot \color{blue}{\left(\frac{1}{12} \cdot {x}^{2} + 1\right)}, 2\right)} \]
        6. distribute-lft-inN/A

          \[\leadsto \frac{2}{\mathsf{fma}\left(x, \color{blue}{x \cdot \left(\frac{1}{12} \cdot {x}^{2}\right) + x \cdot 1}, 2\right)} \]
        7. *-rgt-identityN/A

          \[\leadsto \frac{2}{\mathsf{fma}\left(x, x \cdot \left(\frac{1}{12} \cdot {x}^{2}\right) + \color{blue}{x}, 2\right)} \]
        8. lower-fma.f64N/A

          \[\leadsto \frac{2}{\mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, \frac{1}{12} \cdot {x}^{2}, x\right)}, 2\right)} \]
        9. *-commutativeN/A

          \[\leadsto \frac{2}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{{x}^{2} \cdot \frac{1}{12}}, x\right), 2\right)} \]
        10. lower-*.f64N/A

          \[\leadsto \frac{2}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{{x}^{2} \cdot \frac{1}{12}}, x\right), 2\right)} \]
        11. unpow2N/A

          \[\leadsto \frac{2}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\left(x \cdot x\right)} \cdot \frac{1}{12}, x\right), 2\right)} \]
        12. lower-*.f6477.0

          \[\leadsto \frac{2}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\left(x \cdot x\right)} \cdot 0.08333333333333333, x\right), 2\right)} \]
      5. Applied rewrites77.0%

        \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \left(x \cdot x\right) \cdot 0.08333333333333333, x\right), 2\right)}} \]
      6. Taylor expanded in x around inf

        \[\leadsto \color{blue}{\frac{24}{{x}^{4}}} \]
      7. Step-by-step derivation
        1. lower-/.f64N/A

          \[\leadsto \color{blue}{\frac{24}{{x}^{4}}} \]
        2. metadata-evalN/A

          \[\leadsto \frac{24}{{x}^{\color{blue}{\left(2 \cdot 2\right)}}} \]
        3. pow-sqrN/A

          \[\leadsto \frac{24}{\color{blue}{{x}^{2} \cdot {x}^{2}}} \]
        4. unpow2N/A

          \[\leadsto \frac{24}{\color{blue}{\left(x \cdot x\right)} \cdot {x}^{2}} \]
        5. associate-*l*N/A

          \[\leadsto \frac{24}{\color{blue}{x \cdot \left(x \cdot {x}^{2}\right)}} \]
        6. unpow2N/A

          \[\leadsto \frac{24}{x \cdot \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right)} \]
        7. cube-multN/A

          \[\leadsto \frac{24}{x \cdot \color{blue}{{x}^{3}}} \]
        8. lower-*.f64N/A

          \[\leadsto \frac{24}{\color{blue}{x \cdot {x}^{3}}} \]
        9. cube-multN/A

          \[\leadsto \frac{24}{x \cdot \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)}} \]
        10. unpow2N/A

          \[\leadsto \frac{24}{x \cdot \left(x \cdot \color{blue}{{x}^{2}}\right)} \]
        11. lower-*.f64N/A

          \[\leadsto \frac{24}{x \cdot \color{blue}{\left(x \cdot {x}^{2}\right)}} \]
        12. unpow2N/A

          \[\leadsto \frac{24}{x \cdot \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right)} \]
        13. lower-*.f6477.0

          \[\leadsto \frac{24}{x \cdot \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right)} \]
      8. Applied rewrites77.0%

        \[\leadsto \color{blue}{\frac{24}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}} \]
    3. Recombined 2 regimes into one program.
    4. Add Preprocessing

    Alternative 5: 76.4% accurate, 1.0× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{x} + e^{-x} \leq 4:\\ \;\;\;\;\mathsf{fma}\left(-0.5, x \cdot x, 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{2}{x \cdot x}\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= (+ (exp x) (exp (- x))) 4.0) (fma -0.5 (* x x) 1.0) (/ 2.0 (* x x))))
    double code(double x) {
    	double tmp;
    	if ((exp(x) + exp(-x)) <= 4.0) {
    		tmp = fma(-0.5, (x * x), 1.0);
    	} else {
    		tmp = 2.0 / (x * x);
    	}
    	return tmp;
    }
    
    function code(x)
    	tmp = 0.0
    	if (Float64(exp(x) + exp(Float64(-x))) <= 4.0)
    		tmp = fma(-0.5, Float64(x * x), 1.0);
    	else
    		tmp = Float64(2.0 / Float64(x * x));
    	end
    	return tmp
    end
    
    code[x_] := If[LessEqual[N[(N[Exp[x], $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision], 4.0], N[(-0.5 * N[(x * x), $MachinePrecision] + 1.0), $MachinePrecision], N[(2.0 / N[(x * x), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;e^{x} + e^{-x} \leq 4:\\
    \;\;\;\;\mathsf{fma}\left(-0.5, x \cdot x, 1\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;\frac{2}{x \cdot x}\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (+.f64 (exp.f64 x) (exp.f64 (neg.f64 x))) < 4

      1. Initial program 100.0%

        \[\frac{2}{e^{x} + e^{-x}} \]
      2. Add Preprocessing
      3. Taylor expanded in x around 0

        \[\leadsto \color{blue}{1 + \frac{-1}{2} \cdot {x}^{2}} \]
      4. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \color{blue}{\frac{-1}{2} \cdot {x}^{2} + 1} \]
        2. lower-fma.f64N/A

          \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-1}{2}, {x}^{2}, 1\right)} \]
        3. unpow2N/A

          \[\leadsto \mathsf{fma}\left(\frac{-1}{2}, \color{blue}{x \cdot x}, 1\right) \]
        4. lower-*.f6499.3

          \[\leadsto \mathsf{fma}\left(-0.5, \color{blue}{x \cdot x}, 1\right) \]
      5. Applied rewrites99.3%

        \[\leadsto \color{blue}{\mathsf{fma}\left(-0.5, x \cdot x, 1\right)} \]

      if 4 < (+.f64 (exp.f64 x) (exp.f64 (neg.f64 x)))

      1. Initial program 100.0%

        \[\frac{2}{e^{x} + e^{-x}} \]
      2. Add Preprocessing
      3. Taylor expanded in x around 0

        \[\leadsto \frac{2}{\color{blue}{2 + {x}^{2}}} \]
      4. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \frac{2}{\color{blue}{{x}^{2} + 2}} \]
        2. unpow2N/A

          \[\leadsto \frac{2}{\color{blue}{x \cdot x} + 2} \]
        3. lower-fma.f6456.8

          \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left(x, x, 2\right)}} \]
      5. Applied rewrites56.8%

        \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left(x, x, 2\right)}} \]
      6. Taylor expanded in x around inf

        \[\leadsto \color{blue}{\frac{2}{{x}^{2}}} \]
      7. Step-by-step derivation
        1. lower-/.f64N/A

          \[\leadsto \color{blue}{\frac{2}{{x}^{2}}} \]
        2. unpow2N/A

          \[\leadsto \frac{2}{\color{blue}{x \cdot x}} \]
        3. lower-*.f6456.8

          \[\leadsto \frac{2}{\color{blue}{x \cdot x}} \]
      8. Applied rewrites56.8%

        \[\leadsto \color{blue}{\frac{2}{x \cdot x}} \]
    3. Recombined 2 regimes into one program.
    4. Add Preprocessing

    Alternative 6: 91.9% accurate, 3.3× speedup?

    \[\begin{array}{l} \\ \frac{1}{\mathsf{fma}\left(x \cdot \left(x \cdot \left(\left(x \cdot \left(x \cdot x\right)\right) \cdot 0.001388888888888889\right)\right), x, \mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, x \cdot 0.041666666666666664, 0.5\right), 1\right)\right)} \end{array} \]
    (FPCore (x)
     :precision binary64
     (/
      1.0
      (fma
       (* x (* x (* (* x (* x x)) 0.001388888888888889)))
       x
       (fma x (* x (fma x (* x 0.041666666666666664) 0.5)) 1.0))))
    double code(double x) {
    	return 1.0 / fma((x * (x * ((x * (x * x)) * 0.001388888888888889))), x, fma(x, (x * fma(x, (x * 0.041666666666666664), 0.5)), 1.0));
    }
    
    function code(x)
    	return Float64(1.0 / fma(Float64(x * Float64(x * Float64(Float64(x * Float64(x * x)) * 0.001388888888888889))), x, fma(x, Float64(x * fma(x, Float64(x * 0.041666666666666664), 0.5)), 1.0)))
    end
    
    code[x_] := N[(1.0 / N[(N[(x * N[(x * N[(N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] * 0.001388888888888889), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] * x + N[(x * N[(x * N[(x * N[(x * 0.041666666666666664), $MachinePrecision] + 0.5), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{1}{\mathsf{fma}\left(x \cdot \left(x \cdot \left(\left(x \cdot \left(x \cdot x\right)\right) \cdot 0.001388888888888889\right)\right), x, \mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, x \cdot 0.041666666666666664, 0.5\right), 1\right)\right)}
    \end{array}
    
    Derivation
    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cosh-undefN/A

        \[\leadsto \frac{2}{\color{blue}{2 \cdot \cosh x}} \]
      2. associate-/r*N/A

        \[\leadsto \color{blue}{\frac{\frac{2}{2}}{\cosh x}} \]
      3. metadata-evalN/A

        \[\leadsto \frac{\color{blue}{1}}{\cosh x} \]
      4. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
      5. lower-cosh.f64100.0

        \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
    4. Applied rewrites100.0%

      \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
    5. Taylor expanded in x around 0

      \[\leadsto \frac{1}{\color{blue}{1 + {x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)}} \]
    6. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \frac{1}{\color{blue}{{x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right) + 1}} \]
      2. lower-fma.f64N/A

        \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)}} \]
      3. unpow2N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)} \]
      5. +-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{{x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right) + \frac{1}{2}}, 1\right)} \]
      6. lower-fma.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right)}, 1\right)} \]
      7. unpow2N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right), 1\right)} \]
      8. lower-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right), 1\right)} \]
      9. +-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{1}{720} \cdot {x}^{2} + \frac{1}{24}}, \frac{1}{2}\right), 1\right)} \]
      10. *-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{{x}^{2} \cdot \frac{1}{720}} + \frac{1}{24}, \frac{1}{2}\right), 1\right)} \]
      11. lower-fma.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{720}, \frac{1}{24}\right)}, \frac{1}{2}\right), 1\right)} \]
      12. unpow2N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{720}, \frac{1}{24}\right), \frac{1}{2}\right), 1\right)} \]
      13. lower-*.f6492.5

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, 0.001388888888888889, 0.041666666666666664\right), 0.5\right), 1\right)} \]
    7. Applied rewrites92.5%

      \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, 0.041666666666666664\right), 0.5\right), 1\right)}} \]
    8. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\left(x \cdot x\right)} \cdot \left(\left(x \cdot x\right) \cdot \frac{1}{720} + \frac{1}{24}\right) + \frac{1}{2}, 1\right)} \]
      2. lift-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \left(x \cdot x\right) \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot \frac{1}{720} + \frac{1}{24}\right) + \frac{1}{2}, 1\right)} \]
      3. lift-fma.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \left(x \cdot x\right) \cdot \color{blue}{\mathsf{fma}\left(x \cdot x, \frac{1}{720}, \frac{1}{24}\right)} + \frac{1}{2}, 1\right)} \]
      4. lift-fma.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \left(x \cdot x\right) \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot \frac{1}{720} + \frac{1}{24}\right)} + \frac{1}{2}, 1\right)} \]
      5. distribute-lft-inN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\left(\left(x \cdot x\right) \cdot \left(\left(x \cdot x\right) \cdot \frac{1}{720}\right) + \left(x \cdot x\right) \cdot \frac{1}{24}\right)} + \frac{1}{2}, 1\right)} \]
      6. associate-+l+N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\left(x \cdot x\right) \cdot \left(\left(x \cdot x\right) \cdot \frac{1}{720}\right) + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right)}, 1\right)} \]
      7. lift-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \left(x \cdot x\right) \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot \frac{1}{720}\right) + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right), 1\right)} \]
      8. associate-*l*N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \left(x \cdot x\right) \cdot \color{blue}{\left(x \cdot \left(x \cdot \frac{1}{720}\right)\right)} + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right), 1\right)} \]
      9. associate-*r*N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\left(\left(x \cdot x\right) \cdot x\right) \cdot \left(x \cdot \frac{1}{720}\right)} + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right), 1\right)} \]
      10. *-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)} \cdot \left(x \cdot \frac{1}{720}\right) + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right), 1\right)} \]
      11. lift-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)} \cdot \left(x \cdot \frac{1}{720}\right) + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right), 1\right)} \]
      12. *-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \left(x \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot \frac{1}{720}\right) + \left(\color{blue}{\frac{1}{24} \cdot \left(x \cdot x\right)} + \frac{1}{2}\right), 1\right)} \]
      13. lower-fma.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left(x \cdot \left(x \cdot x\right), x \cdot \frac{1}{720}, \frac{1}{24} \cdot \left(x \cdot x\right) + \frac{1}{2}\right)}, 1\right)} \]
      14. lower-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot \left(x \cdot x\right), \color{blue}{x \cdot \frac{1}{720}}, \frac{1}{24} \cdot \left(x \cdot x\right) + \frac{1}{2}\right), 1\right)} \]
      15. *-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot \left(x \cdot x\right), x \cdot \frac{1}{720}, \color{blue}{\left(x \cdot x\right) \cdot \frac{1}{24}} + \frac{1}{2}\right), 1\right)} \]
      16. lower-fma.f6492.5

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot \left(x \cdot x\right), x \cdot 0.001388888888888889, \color{blue}{\mathsf{fma}\left(x \cdot x, 0.041666666666666664, 0.5\right)}\right), 1\right)} \]
    9. Applied rewrites92.5%

      \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left(x \cdot \left(x \cdot x\right), x \cdot 0.001388888888888889, \mathsf{fma}\left(x \cdot x, 0.041666666666666664, 0.5\right)\right)}, 1\right)} \]
    10. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{1}{\color{blue}{\left(x \cdot x\right)} \cdot \left(\left(x \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot \frac{1}{720}\right) + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right)\right) + 1} \]
      2. lift-*.f64N/A

        \[\leadsto \frac{1}{\left(x \cdot x\right) \cdot \left(\left(x \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot \left(x \cdot \frac{1}{720}\right) + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right)\right) + 1} \]
      3. lift-*.f64N/A

        \[\leadsto \frac{1}{\left(x \cdot x\right) \cdot \left(\color{blue}{\left(x \cdot \left(x \cdot x\right)\right)} \cdot \left(x \cdot \frac{1}{720}\right) + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right)\right) + 1} \]
      4. lift-*.f64N/A

        \[\leadsto \frac{1}{\left(x \cdot x\right) \cdot \left(\left(x \cdot \left(x \cdot x\right)\right) \cdot \color{blue}{\left(x \cdot \frac{1}{720}\right)} + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right)\right) + 1} \]
      5. lift-*.f64N/A

        \[\leadsto \frac{1}{\left(x \cdot x\right) \cdot \left(\left(x \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot \frac{1}{720}\right) + \left(\color{blue}{\left(x \cdot x\right)} \cdot \frac{1}{24} + \frac{1}{2}\right)\right) + 1} \]
      6. lift-fma.f64N/A

        \[\leadsto \frac{1}{\left(x \cdot x\right) \cdot \left(\left(x \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot \frac{1}{720}\right) + \color{blue}{\mathsf{fma}\left(x \cdot x, \frac{1}{24}, \frac{1}{2}\right)}\right) + 1} \]
      7. lift-fma.f64N/A

        \[\leadsto \frac{1}{\left(x \cdot x\right) \cdot \color{blue}{\mathsf{fma}\left(x \cdot \left(x \cdot x\right), x \cdot \frac{1}{720}, \mathsf{fma}\left(x \cdot x, \frac{1}{24}, \frac{1}{2}\right)\right)} + 1} \]
      8. lift-fma.f64N/A

        \[\leadsto \frac{1}{\left(x \cdot x\right) \cdot \color{blue}{\left(\left(x \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot \frac{1}{720}\right) + \mathsf{fma}\left(x \cdot x, \frac{1}{24}, \frac{1}{2}\right)\right)} + 1} \]
      9. distribute-lft-inN/A

        \[\leadsto \frac{1}{\color{blue}{\left(\left(x \cdot x\right) \cdot \left(\left(x \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot \frac{1}{720}\right)\right) + \left(x \cdot x\right) \cdot \mathsf{fma}\left(x \cdot x, \frac{1}{24}, \frac{1}{2}\right)\right)} + 1} \]
      10. associate-+l+N/A

        \[\leadsto \frac{1}{\color{blue}{\left(x \cdot x\right) \cdot \left(\left(x \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot \frac{1}{720}\right)\right) + \left(\left(x \cdot x\right) \cdot \mathsf{fma}\left(x \cdot x, \frac{1}{24}, \frac{1}{2}\right) + 1\right)}} \]
    11. Applied rewrites92.5%

      \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(\left(x \cdot \left(\left(x \cdot \left(x \cdot x\right)\right) \cdot 0.001388888888888889\right)\right) \cdot x, x, \mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, x \cdot 0.041666666666666664, 0.5\right), 1\right)\right)}} \]
    12. Final simplification92.5%

      \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot \left(x \cdot \left(\left(x \cdot \left(x \cdot x\right)\right) \cdot 0.001388888888888889\right)\right), x, \mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, x \cdot 0.041666666666666664, 0.5\right), 1\right)\right)} \]
    13. Add Preprocessing

    Alternative 7: 91.9% accurate, 4.8× speedup?

    \[\begin{array}{l} \\ \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, 0.041666666666666664\right), 0.5\right), 1\right)} \end{array} \]
    (FPCore (x)
     :precision binary64
     (/
      1.0
      (fma
       (* x x)
       (fma (* x x) (fma (* x x) 0.001388888888888889 0.041666666666666664) 0.5)
       1.0)))
    double code(double x) {
    	return 1.0 / fma((x * x), fma((x * x), fma((x * x), 0.001388888888888889, 0.041666666666666664), 0.5), 1.0);
    }
    
    function code(x)
    	return Float64(1.0 / fma(Float64(x * x), fma(Float64(x * x), fma(Float64(x * x), 0.001388888888888889, 0.041666666666666664), 0.5), 1.0))
    end
    
    code[x_] := N[(1.0 / N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * 0.001388888888888889 + 0.041666666666666664), $MachinePrecision] + 0.5), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, 0.041666666666666664\right), 0.5\right), 1\right)}
    \end{array}
    
    Derivation
    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cosh-undefN/A

        \[\leadsto \frac{2}{\color{blue}{2 \cdot \cosh x}} \]
      2. associate-/r*N/A

        \[\leadsto \color{blue}{\frac{\frac{2}{2}}{\cosh x}} \]
      3. metadata-evalN/A

        \[\leadsto \frac{\color{blue}{1}}{\cosh x} \]
      4. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
      5. lower-cosh.f64100.0

        \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
    4. Applied rewrites100.0%

      \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
    5. Taylor expanded in x around 0

      \[\leadsto \frac{1}{\color{blue}{1 + {x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)}} \]
    6. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \frac{1}{\color{blue}{{x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right) + 1}} \]
      2. lower-fma.f64N/A

        \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)}} \]
      3. unpow2N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)} \]
      5. +-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{{x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right) + \frac{1}{2}}, 1\right)} \]
      6. lower-fma.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right)}, 1\right)} \]
      7. unpow2N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right), 1\right)} \]
      8. lower-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right), 1\right)} \]
      9. +-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{1}{720} \cdot {x}^{2} + \frac{1}{24}}, \frac{1}{2}\right), 1\right)} \]
      10. *-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{{x}^{2} \cdot \frac{1}{720}} + \frac{1}{24}, \frac{1}{2}\right), 1\right)} \]
      11. lower-fma.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{720}, \frac{1}{24}\right)}, \frac{1}{2}\right), 1\right)} \]
      12. unpow2N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{720}, \frac{1}{24}\right), \frac{1}{2}\right), 1\right)} \]
      13. lower-*.f6492.5

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, 0.001388888888888889, 0.041666666666666664\right), 0.5\right), 1\right)} \]
    7. Applied rewrites92.5%

      \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, 0.041666666666666664\right), 0.5\right), 1\right)}} \]
    8. Add Preprocessing

    Alternative 8: 91.7% accurate, 4.9× speedup?

    \[\begin{array}{l} \\ \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot \left(x \cdot x\right), x \cdot 0.001388888888888889, 0.5\right), 1\right)} \end{array} \]
    (FPCore (x)
     :precision binary64
     (/ 1.0 (fma (* x x) (fma (* x (* x x)) (* x 0.001388888888888889) 0.5) 1.0)))
    double code(double x) {
    	return 1.0 / fma((x * x), fma((x * (x * x)), (x * 0.001388888888888889), 0.5), 1.0);
    }
    
    function code(x)
    	return Float64(1.0 / fma(Float64(x * x), fma(Float64(x * Float64(x * x)), Float64(x * 0.001388888888888889), 0.5), 1.0))
    end
    
    code[x_] := N[(1.0 / N[(N[(x * x), $MachinePrecision] * N[(N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision] * N[(x * 0.001388888888888889), $MachinePrecision] + 0.5), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot \left(x \cdot x\right), x \cdot 0.001388888888888889, 0.5\right), 1\right)}
    \end{array}
    
    Derivation
    1. Initial program 100.0%

      \[\frac{2}{e^{x} + e^{-x}} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. cosh-undefN/A

        \[\leadsto \frac{2}{\color{blue}{2 \cdot \cosh x}} \]
      2. associate-/r*N/A

        \[\leadsto \color{blue}{\frac{\frac{2}{2}}{\cosh x}} \]
      3. metadata-evalN/A

        \[\leadsto \frac{\color{blue}{1}}{\cosh x} \]
      4. lower-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
      5. lower-cosh.f64100.0

        \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
    4. Applied rewrites100.0%

      \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
    5. Taylor expanded in x around 0

      \[\leadsto \frac{1}{\color{blue}{1 + {x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)}} \]
    6. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \frac{1}{\color{blue}{{x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right) + 1}} \]
      2. lower-fma.f64N/A

        \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)}} \]
      3. unpow2N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)} \]
      5. +-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{{x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right) + \frac{1}{2}}, 1\right)} \]
      6. lower-fma.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right)}, 1\right)} \]
      7. unpow2N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right), 1\right)} \]
      8. lower-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right), 1\right)} \]
      9. +-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{1}{720} \cdot {x}^{2} + \frac{1}{24}}, \frac{1}{2}\right), 1\right)} \]
      10. *-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{{x}^{2} \cdot \frac{1}{720}} + \frac{1}{24}, \frac{1}{2}\right), 1\right)} \]
      11. lower-fma.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{720}, \frac{1}{24}\right)}, \frac{1}{2}\right), 1\right)} \]
      12. unpow2N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{720}, \frac{1}{24}\right), \frac{1}{2}\right), 1\right)} \]
      13. lower-*.f6492.5

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, 0.001388888888888889, 0.041666666666666664\right), 0.5\right), 1\right)} \]
    7. Applied rewrites92.5%

      \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, 0.041666666666666664\right), 0.5\right), 1\right)}} \]
    8. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\left(x \cdot x\right)} \cdot \left(\left(x \cdot x\right) \cdot \frac{1}{720} + \frac{1}{24}\right) + \frac{1}{2}, 1\right)} \]
      2. lift-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \left(x \cdot x\right) \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot \frac{1}{720} + \frac{1}{24}\right) + \frac{1}{2}, 1\right)} \]
      3. lift-fma.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \left(x \cdot x\right) \cdot \color{blue}{\mathsf{fma}\left(x \cdot x, \frac{1}{720}, \frac{1}{24}\right)} + \frac{1}{2}, 1\right)} \]
      4. lift-fma.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \left(x \cdot x\right) \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot \frac{1}{720} + \frac{1}{24}\right)} + \frac{1}{2}, 1\right)} \]
      5. distribute-lft-inN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\left(\left(x \cdot x\right) \cdot \left(\left(x \cdot x\right) \cdot \frac{1}{720}\right) + \left(x \cdot x\right) \cdot \frac{1}{24}\right)} + \frac{1}{2}, 1\right)} \]
      6. associate-+l+N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\left(x \cdot x\right) \cdot \left(\left(x \cdot x\right) \cdot \frac{1}{720}\right) + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right)}, 1\right)} \]
      7. lift-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \left(x \cdot x\right) \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot \frac{1}{720}\right) + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right), 1\right)} \]
      8. associate-*l*N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \left(x \cdot x\right) \cdot \color{blue}{\left(x \cdot \left(x \cdot \frac{1}{720}\right)\right)} + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right), 1\right)} \]
      9. associate-*r*N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\left(\left(x \cdot x\right) \cdot x\right) \cdot \left(x \cdot \frac{1}{720}\right)} + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right), 1\right)} \]
      10. *-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)} \cdot \left(x \cdot \frac{1}{720}\right) + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right), 1\right)} \]
      11. lift-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\left(x \cdot \left(x \cdot x\right)\right)} \cdot \left(x \cdot \frac{1}{720}\right) + \left(\left(x \cdot x\right) \cdot \frac{1}{24} + \frac{1}{2}\right), 1\right)} \]
      12. *-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \left(x \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot \frac{1}{720}\right) + \left(\color{blue}{\frac{1}{24} \cdot \left(x \cdot x\right)} + \frac{1}{2}\right), 1\right)} \]
      13. lower-fma.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left(x \cdot \left(x \cdot x\right), x \cdot \frac{1}{720}, \frac{1}{24} \cdot \left(x \cdot x\right) + \frac{1}{2}\right)}, 1\right)} \]
      14. lower-*.f64N/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot \left(x \cdot x\right), \color{blue}{x \cdot \frac{1}{720}}, \frac{1}{24} \cdot \left(x \cdot x\right) + \frac{1}{2}\right), 1\right)} \]
      15. *-commutativeN/A

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot \left(x \cdot x\right), x \cdot \frac{1}{720}, \color{blue}{\left(x \cdot x\right) \cdot \frac{1}{24}} + \frac{1}{2}\right), 1\right)} \]
      16. lower-fma.f6492.5

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot \left(x \cdot x\right), x \cdot 0.001388888888888889, \color{blue}{\mathsf{fma}\left(x \cdot x, 0.041666666666666664, 0.5\right)}\right), 1\right)} \]
    9. Applied rewrites92.5%

      \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left(x \cdot \left(x \cdot x\right), x \cdot 0.001388888888888889, \mathsf{fma}\left(x \cdot x, 0.041666666666666664, 0.5\right)\right)}, 1\right)} \]
    10. Taylor expanded in x around 0

      \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot \left(x \cdot x\right), x \cdot \frac{1}{720}, \color{blue}{\frac{1}{2}}\right), 1\right)} \]
    11. Step-by-step derivation
      1. Applied rewrites92.2%

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot \left(x \cdot x\right), x \cdot 0.001388888888888889, \color{blue}{0.5}\right), 1\right)} \]
      2. Add Preprocessing

      Alternative 9: 87.7% accurate, 6.4× speedup?

      \[\begin{array}{l} \\ \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.041666666666666664, 0.5\right), 1\right)} \end{array} \]
      (FPCore (x)
       :precision binary64
       (/ 1.0 (fma (* x x) (fma (* x x) 0.041666666666666664 0.5) 1.0)))
      double code(double x) {
      	return 1.0 / fma((x * x), fma((x * x), 0.041666666666666664, 0.5), 1.0);
      }
      
      function code(x)
      	return Float64(1.0 / fma(Float64(x * x), fma(Float64(x * x), 0.041666666666666664, 0.5), 1.0))
      end
      
      code[x_] := N[(1.0 / N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * 0.041666666666666664 + 0.5), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.041666666666666664, 0.5\right), 1\right)}
      \end{array}
      
      Derivation
      1. Initial program 100.0%

        \[\frac{2}{e^{x} + e^{-x}} \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. cosh-undefN/A

          \[\leadsto \frac{2}{\color{blue}{2 \cdot \cosh x}} \]
        2. associate-/r*N/A

          \[\leadsto \color{blue}{\frac{\frac{2}{2}}{\cosh x}} \]
        3. metadata-evalN/A

          \[\leadsto \frac{\color{blue}{1}}{\cosh x} \]
        4. lower-/.f64N/A

          \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
        5. lower-cosh.f64100.0

          \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
      4. Applied rewrites100.0%

        \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
      5. Taylor expanded in x around 0

        \[\leadsto \frac{1}{\color{blue}{1 + {x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right)}} \]
      6. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \frac{1}{\color{blue}{{x}^{2} \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right) + 1}} \]
        2. lower-fma.f64N/A

          \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)}} \]
        3. unpow2N/A

          \[\leadsto \frac{1}{\mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)} \]
        4. lower-*.f64N/A

          \[\leadsto \frac{1}{\mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right), 1\right)} \]
        5. +-commutativeN/A

          \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{{x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right) + \frac{1}{2}}, 1\right)} \]
        6. lower-fma.f64N/A

          \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right)}, 1\right)} \]
        7. unpow2N/A

          \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right), 1\right)} \]
        8. lower-*.f64N/A

          \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{24} + \frac{1}{720} \cdot {x}^{2}, \frac{1}{2}\right), 1\right)} \]
        9. +-commutativeN/A

          \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{1}{720} \cdot {x}^{2} + \frac{1}{24}}, \frac{1}{2}\right), 1\right)} \]
        10. *-commutativeN/A

          \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{{x}^{2} \cdot \frac{1}{720}} + \frac{1}{24}, \frac{1}{2}\right), 1\right)} \]
        11. lower-fma.f64N/A

          \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{720}, \frac{1}{24}\right)}, \frac{1}{2}\right), 1\right)} \]
        12. unpow2N/A

          \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{720}, \frac{1}{24}\right), \frac{1}{2}\right), 1\right)} \]
        13. lower-*.f6492.5

          \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, 0.001388888888888889, 0.041666666666666664\right), 0.5\right), 1\right)} \]
      7. Applied rewrites92.5%

        \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, 0.001388888888888889, 0.041666666666666664\right), 0.5\right), 1\right)}} \]
      8. Taylor expanded in x around 0

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{\frac{1}{24}}, \frac{1}{2}\right), 1\right)} \]
      9. Step-by-step derivation
        1. Applied rewrites89.8%

          \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \color{blue}{0.041666666666666664}, 0.5\right), 1\right)} \]
        2. Add Preprocessing

        Alternative 10: 76.4% accurate, 12.1× speedup?

        \[\begin{array}{l} \\ \frac{2}{\mathsf{fma}\left(x, x, 2\right)} \end{array} \]
        (FPCore (x) :precision binary64 (/ 2.0 (fma x x 2.0)))
        double code(double x) {
        	return 2.0 / fma(x, x, 2.0);
        }
        
        function code(x)
        	return Float64(2.0 / fma(x, x, 2.0))
        end
        
        code[x_] := N[(2.0 / N[(x * x + 2.0), $MachinePrecision]), $MachinePrecision]
        
        \begin{array}{l}
        
        \\
        \frac{2}{\mathsf{fma}\left(x, x, 2\right)}
        \end{array}
        
        Derivation
        1. Initial program 100.0%

          \[\frac{2}{e^{x} + e^{-x}} \]
        2. Add Preprocessing
        3. Taylor expanded in x around 0

          \[\leadsto \frac{2}{\color{blue}{2 + {x}^{2}}} \]
        4. Step-by-step derivation
          1. +-commutativeN/A

            \[\leadsto \frac{2}{\color{blue}{{x}^{2} + 2}} \]
          2. unpow2N/A

            \[\leadsto \frac{2}{\color{blue}{x \cdot x} + 2} \]
          3. lower-fma.f6480.7

            \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left(x, x, 2\right)}} \]
        5. Applied rewrites80.7%

          \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left(x, x, 2\right)}} \]
        6. Add Preprocessing

        Alternative 11: 50.8% accurate, 217.0× speedup?

        \[\begin{array}{l} \\ 1 \end{array} \]
        (FPCore (x) :precision binary64 1.0)
        double code(double x) {
        	return 1.0;
        }
        
        real(8) function code(x)
            real(8), intent (in) :: x
            code = 1.0d0
        end function
        
        public static double code(double x) {
        	return 1.0;
        }
        
        def code(x):
        	return 1.0
        
        function code(x)
        	return 1.0
        end
        
        function tmp = code(x)
        	tmp = 1.0;
        end
        
        code[x_] := 1.0
        
        \begin{array}{l}
        
        \\
        1
        \end{array}
        
        Derivation
        1. Initial program 100.0%

          \[\frac{2}{e^{x} + e^{-x}} \]
        2. Add Preprocessing
        3. Taylor expanded in x around 0

          \[\leadsto \color{blue}{1} \]
        4. Step-by-step derivation
          1. Applied rewrites56.9%

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

          Reproduce

          ?
          herbie shell --seed 2024219 
          (FPCore (x)
            :name "Hyperbolic secant"
            :precision binary64
            (/ 2.0 (+ (exp x) (exp (- x)))))