Hyperbolic secant

Percentage Accurate: 100.0% → 100.0%
Time: 6.0s
Alternatives: 9
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 9 alternatives:

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

Initial Program: 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, 0.9× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} t_0 := e^{-x\_m}\\ \frac{2}{\frac{1}{t\_0} + t\_0} \end{array} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (let* ((t_0 (exp (- x_m)))) (/ 2.0 (+ (/ 1.0 t_0) t_0))))
x_m = fabs(x);
double code(double x_m) {
	double t_0 = exp(-x_m);
	return 2.0 / ((1.0 / t_0) + t_0);
}
x_m = abs(x)
real(8) function code(x_m)
    real(8), intent (in) :: x_m
    real(8) :: t_0
    t_0 = exp(-x_m)
    code = 2.0d0 / ((1.0d0 / t_0) + t_0)
end function
x_m = Math.abs(x);
public static double code(double x_m) {
	double t_0 = Math.exp(-x_m);
	return 2.0 / ((1.0 / t_0) + t_0);
}
x_m = math.fabs(x)
def code(x_m):
	t_0 = math.exp(-x_m)
	return 2.0 / ((1.0 / t_0) + t_0)
x_m = abs(x)
function code(x_m)
	t_0 = exp(Float64(-x_m))
	return Float64(2.0 / Float64(Float64(1.0 / t_0) + t_0))
end
x_m = abs(x);
function tmp = code(x_m)
	t_0 = exp(-x_m);
	tmp = 2.0 / ((1.0 / t_0) + t_0);
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := Block[{t$95$0 = N[Exp[(-x$95$m)], $MachinePrecision]}, N[(2.0 / N[(N[(1.0 / t$95$0), $MachinePrecision] + t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}
x_m = \left|x\right|

\\
\begin{array}{l}
t_0 := e^{-x\_m}\\
\frac{2}{\frac{1}{t\_0} + t\_0}
\end{array}
\end{array}
Derivation
  1. Initial program 100.0%

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

      \[\leadsto \frac{2}{\color{blue}{\frac{e^{x}}{1}} + e^{-x}} \]
    2. clear-numN/A

      \[\leadsto \frac{2}{\color{blue}{\frac{1}{\frac{1}{e^{x}}}} + e^{-x}} \]
    3. lift-exp.f64N/A

      \[\leadsto \frac{2}{\frac{1}{\frac{1}{\color{blue}{e^{x}}}} + e^{-x}} \]
    4. exp-negN/A

      \[\leadsto \frac{2}{\frac{1}{\color{blue}{e^{\mathsf{neg}\left(x\right)}}} + e^{-x}} \]
    5. lift-neg.f64N/A

      \[\leadsto \frac{2}{\frac{1}{e^{\color{blue}{-x}}} + e^{-x}} \]
    6. lift-exp.f64N/A

      \[\leadsto \frac{2}{\frac{1}{\color{blue}{e^{-x}}} + e^{-x}} \]
    7. lower-/.f64100.0

      \[\leadsto \frac{2}{\color{blue}{\frac{1}{e^{-x}}} + e^{-x}} \]
  4. Applied rewrites100.0%

    \[\leadsto \frac{2}{\color{blue}{\frac{1}{e^{-x}}} + e^{-x}} \]
  5. Add Preprocessing

Alternative 2: 100.0% accurate, 1.9× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \frac{1}{\cosh x\_m} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m) :precision binary64 (/ 1.0 (cosh x_m)))
x_m = fabs(x);
double code(double x_m) {
	return 1.0 / cosh(x_m);
}
x_m = abs(x)
real(8) function code(x_m)
    real(8), intent (in) :: x_m
    code = 1.0d0 / cosh(x_m)
end function
x_m = Math.abs(x);
public static double code(double x_m) {
	return 1.0 / Math.cosh(x_m);
}
x_m = math.fabs(x)
def code(x_m):
	return 1.0 / math.cosh(x_m)
x_m = abs(x)
function code(x_m)
	return Float64(1.0 / cosh(x_m))
end
x_m = abs(x);
function tmp = code(x_m)
	tmp = 1.0 / cosh(x_m);
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := N[(1.0 / N[Cosh[x$95$m], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|

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

    \[\frac{2}{e^{x} + e^{-x}} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{2}{e^{x} + e^{-x}}} \]
    2. clear-numN/A

      \[\leadsto \color{blue}{\frac{1}{\frac{e^{x} + e^{-x}}{2}}} \]
    3. lift-+.f64N/A

      \[\leadsto \frac{1}{\frac{\color{blue}{e^{x} + e^{-x}}}{2}} \]
    4. lift-exp.f64N/A

      \[\leadsto \frac{1}{\frac{\color{blue}{e^{x}} + e^{-x}}{2}} \]
    5. lift-exp.f64N/A

      \[\leadsto \frac{1}{\frac{e^{x} + \color{blue}{e^{-x}}}{2}} \]
    6. lift-neg.f64N/A

      \[\leadsto \frac{1}{\frac{e^{x} + e^{\color{blue}{\mathsf{neg}\left(x\right)}}}{2}} \]
    7. cosh-defN/A

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

      \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
    9. 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 3: 92.5% accurate, 4.8× speedup?

\[\begin{array}{l} x_m = \left|x\right| \\ \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(x\_m \cdot x\_m, 0.001388888888888889, 0.041666666666666664\right), x\_m \cdot x\_m, 0.5\right) \cdot x\_m, x\_m, 1\right)} \end{array} \]
x_m = (fabs.f64 x)
(FPCore (x_m)
 :precision binary64
 (/
  1.0
  (fma
   (*
    (fma
     (fma (* x_m x_m) 0.001388888888888889 0.041666666666666664)
     (* x_m x_m)
     0.5)
    x_m)
   x_m
   1.0)))
x_m = fabs(x);
double code(double x_m) {
	return 1.0 / fma((fma(fma((x_m * x_m), 0.001388888888888889, 0.041666666666666664), (x_m * x_m), 0.5) * x_m), x_m, 1.0);
}
x_m = abs(x)
function code(x_m)
	return Float64(1.0 / fma(Float64(fma(fma(Float64(x_m * x_m), 0.001388888888888889, 0.041666666666666664), Float64(x_m * x_m), 0.5) * x_m), x_m, 1.0))
end
x_m = N[Abs[x], $MachinePrecision]
code[x$95$m_] := N[(1.0 / N[(N[(N[(N[(N[(x$95$m * x$95$m), $MachinePrecision] * 0.001388888888888889 + 0.041666666666666664), $MachinePrecision] * N[(x$95$m * x$95$m), $MachinePrecision] + 0.5), $MachinePrecision] * x$95$m), $MachinePrecision] * x$95$m + 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}
x_m = \left|x\right|

\\
\frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(x\_m \cdot x\_m, 0.001388888888888889, 0.041666666666666664\right), x\_m \cdot x\_m, 0.5\right) \cdot x\_m, x\_m, 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. lift-/.f64N/A

      \[\leadsto \color{blue}{\frac{2}{e^{x} + e^{-x}}} \]
    2. clear-numN/A

      \[\leadsto \color{blue}{\frac{1}{\frac{e^{x} + e^{-x}}{2}}} \]
    3. lift-+.f64N/A

      \[\leadsto \frac{1}{\frac{\color{blue}{e^{x} + e^{-x}}}{2}} \]
    4. lift-exp.f64N/A

      \[\leadsto \frac{1}{\frac{\color{blue}{e^{x}} + e^{-x}}{2}} \]
    5. lift-exp.f64N/A

      \[\leadsto \frac{1}{\frac{e^{x} + \color{blue}{e^{-x}}}{2}} \]
    6. lift-neg.f64N/A

      \[\leadsto \frac{1}{\frac{e^{x} + e^{\color{blue}{\mathsf{neg}\left(x\right)}}}{2}} \]
    7. cosh-defN/A

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

      \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
    9. 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. *-commutativeN/A

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

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

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

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

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

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

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

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

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

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

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

      \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{720}, x \cdot x, \frac{1}{24}\right), x \cdot x, \frac{1}{2}\right), \color{blue}{x \cdot x}, 1\right)} \]
    14. lower-*.f6491.9

      \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.001388888888888889, x \cdot x, 0.041666666666666664\right), x \cdot x, 0.5\right), \color{blue}{x \cdot x}, 1\right)} \]
  7. Applied rewrites91.9%

    \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.001388888888888889, x \cdot x, 0.041666666666666664\right), x \cdot x, 0.5\right), x \cdot x, 1\right)}} \]
  8. Step-by-step derivation
    1. Applied rewrites91.9%

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

    Alternative 4: 92.0% accurate, 4.9× speedup?

    \[\begin{array}{l} x_m = \left|x\right| \\ \frac{1}{\mathsf{fma}\left(\left(\mathsf{fma}\left(0.001388888888888889, x\_m \cdot x\_m, 0.041666666666666664\right) \cdot x\_m\right) \cdot x\_m, x\_m \cdot x\_m, 1\right)} \end{array} \]
    x_m = (fabs.f64 x)
    (FPCore (x_m)
     :precision binary64
     (/
      1.0
      (fma
       (* (* (fma 0.001388888888888889 (* x_m x_m) 0.041666666666666664) x_m) x_m)
       (* x_m x_m)
       1.0)))
    x_m = fabs(x);
    double code(double x_m) {
    	return 1.0 / fma(((fma(0.001388888888888889, (x_m * x_m), 0.041666666666666664) * x_m) * x_m), (x_m * x_m), 1.0);
    }
    
    x_m = abs(x)
    function code(x_m)
    	return Float64(1.0 / fma(Float64(Float64(fma(0.001388888888888889, Float64(x_m * x_m), 0.041666666666666664) * x_m) * x_m), Float64(x_m * x_m), 1.0))
    end
    
    x_m = N[Abs[x], $MachinePrecision]
    code[x$95$m_] := N[(1.0 / N[(N[(N[(N[(0.001388888888888889 * N[(x$95$m * x$95$m), $MachinePrecision] + 0.041666666666666664), $MachinePrecision] * x$95$m), $MachinePrecision] * x$95$m), $MachinePrecision] * N[(x$95$m * x$95$m), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]
    
    \begin{array}{l}
    x_m = \left|x\right|
    
    \\
    \frac{1}{\mathsf{fma}\left(\left(\mathsf{fma}\left(0.001388888888888889, x\_m \cdot x\_m, 0.041666666666666664\right) \cdot x\_m\right) \cdot x\_m, x\_m \cdot x\_m, 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. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{2}{e^{x} + e^{-x}}} \]
      2. clear-numN/A

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{x} + e^{-x}}{2}}} \]
      3. lift-+.f64N/A

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{x} + e^{-x}}}{2}} \]
      4. lift-exp.f64N/A

        \[\leadsto \frac{1}{\frac{\color{blue}{e^{x}} + e^{-x}}{2}} \]
      5. lift-exp.f64N/A

        \[\leadsto \frac{1}{\frac{e^{x} + \color{blue}{e^{-x}}}{2}} \]
      6. lift-neg.f64N/A

        \[\leadsto \frac{1}{\frac{e^{x} + e^{\color{blue}{\mathsf{neg}\left(x\right)}}}{2}} \]
      7. cosh-defN/A

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

        \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
      9. 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. *-commutativeN/A

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{720}, x \cdot x, \frac{1}{24}\right), x \cdot x, \frac{1}{2}\right), \color{blue}{x \cdot x}, 1\right)} \]
      14. lower-*.f6491.9

        \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.001388888888888889, x \cdot x, 0.041666666666666664\right), x \cdot x, 0.5\right), \color{blue}{x \cdot x}, 1\right)} \]
    7. Applied rewrites91.9%

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

      \[\leadsto \frac{1}{\mathsf{fma}\left({x}^{4} \cdot \left(\frac{1}{720} + \frac{1}{24} \cdot \frac{1}{{x}^{2}}\right), \color{blue}{x} \cdot x, 1\right)} \]
    9. Step-by-step derivation
      1. Applied rewrites91.1%

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

      Alternative 5: 88.4% accurate, 5.6× speedup?

      \[\begin{array}{l} x_m = \left|x\right| \\ \begin{array}{l} \mathbf{if}\;x\_m \leq 1.4:\\ \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(0.20833333333333334, x\_m \cdot x\_m, -0.5\right), x\_m \cdot x\_m, 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\left(\mathsf{fma}\left(0.041666666666666664, x\_m \cdot x\_m, 0.5\right) \cdot x\_m\right) \cdot x\_m}\\ \end{array} \end{array} \]
      x_m = (fabs.f64 x)
      (FPCore (x_m)
       :precision binary64
       (if (<= x_m 1.4)
         (fma (fma 0.20833333333333334 (* x_m x_m) -0.5) (* x_m x_m) 1.0)
         (/ 1.0 (* (* (fma 0.041666666666666664 (* x_m x_m) 0.5) x_m) x_m))))
      x_m = fabs(x);
      double code(double x_m) {
      	double tmp;
      	if (x_m <= 1.4) {
      		tmp = fma(fma(0.20833333333333334, (x_m * x_m), -0.5), (x_m * x_m), 1.0);
      	} else {
      		tmp = 1.0 / ((fma(0.041666666666666664, (x_m * x_m), 0.5) * x_m) * x_m);
      	}
      	return tmp;
      }
      
      x_m = abs(x)
      function code(x_m)
      	tmp = 0.0
      	if (x_m <= 1.4)
      		tmp = fma(fma(0.20833333333333334, Float64(x_m * x_m), -0.5), Float64(x_m * x_m), 1.0);
      	else
      		tmp = Float64(1.0 / Float64(Float64(fma(0.041666666666666664, Float64(x_m * x_m), 0.5) * x_m) * x_m));
      	end
      	return tmp
      end
      
      x_m = N[Abs[x], $MachinePrecision]
      code[x$95$m_] := If[LessEqual[x$95$m, 1.4], N[(N[(0.20833333333333334 * N[(x$95$m * x$95$m), $MachinePrecision] + -0.5), $MachinePrecision] * N[(x$95$m * x$95$m), $MachinePrecision] + 1.0), $MachinePrecision], N[(1.0 / N[(N[(N[(0.041666666666666664 * N[(x$95$m * x$95$m), $MachinePrecision] + 0.5), $MachinePrecision] * x$95$m), $MachinePrecision] * x$95$m), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      x_m = \left|x\right|
      
      \\
      \begin{array}{l}
      \mathbf{if}\;x\_m \leq 1.4:\\
      \;\;\;\;\mathsf{fma}\left(\mathsf{fma}\left(0.20833333333333334, x\_m \cdot x\_m, -0.5\right), x\_m \cdot x\_m, 1\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\frac{1}{\left(\mathsf{fma}\left(0.041666666666666664, x\_m \cdot x\_m, 0.5\right) \cdot x\_m\right) \cdot x\_m}\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if x < 1.3999999999999999

        1. Initial program 100.0%

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

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

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

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

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

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

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

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

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

            \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(\frac{5}{24}, x \cdot x, \frac{-1}{2}\right), \color{blue}{x \cdot x}, 1\right) \]
          10. lower-*.f6465.3

            \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(0.20833333333333334, x \cdot x, -0.5\right), \color{blue}{x \cdot x}, 1\right) \]
        5. Applied rewrites65.3%

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

        if 1.3999999999999999 < x

        1. Initial program 100.0%

          \[\frac{2}{e^{x} + e^{-x}} \]
        2. Add Preprocessing
        3. Step-by-step derivation
          1. lift-/.f64N/A

            \[\leadsto \color{blue}{\frac{2}{e^{x} + e^{-x}}} \]
          2. clear-numN/A

            \[\leadsto \color{blue}{\frac{1}{\frac{e^{x} + e^{-x}}{2}}} \]
          3. lift-+.f64N/A

            \[\leadsto \frac{1}{\frac{\color{blue}{e^{x} + e^{-x}}}{2}} \]
          4. lift-exp.f64N/A

            \[\leadsto \frac{1}{\frac{\color{blue}{e^{x}} + e^{-x}}{2}} \]
          5. lift-exp.f64N/A

            \[\leadsto \frac{1}{\frac{e^{x} + \color{blue}{e^{-x}}}{2}} \]
          6. lift-neg.f64N/A

            \[\leadsto \frac{1}{\frac{e^{x} + e^{\color{blue}{\mathsf{neg}\left(x\right)}}}{2}} \]
          7. cosh-defN/A

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

            \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
          9. 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

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

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

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

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

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

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

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

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

            \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{24}, x \cdot x, \frac{1}{2}\right), \color{blue}{x \cdot x}, 1\right)} \]
          9. lower-*.f6478.7

            \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x \cdot x, 0.5\right), \color{blue}{x \cdot x}, 1\right)} \]
        7. Applied rewrites78.7%

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

          \[\leadsto \frac{1}{{x}^{4} \cdot \color{blue}{\left(\frac{1}{24} + \frac{1}{2} \cdot \frac{1}{{x}^{2}}\right)}} \]
        9. Step-by-step derivation
          1. Applied rewrites78.7%

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

        Alternative 6: 88.4% accurate, 6.4× speedup?

        \[\begin{array}{l} x_m = \left|x\right| \\ \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x\_m \cdot x\_m, 0.5\right), x\_m \cdot x\_m, 1\right)} \end{array} \]
        x_m = (fabs.f64 x)
        (FPCore (x_m)
         :precision binary64
         (/ 1.0 (fma (fma 0.041666666666666664 (* x_m x_m) 0.5) (* x_m x_m) 1.0)))
        x_m = fabs(x);
        double code(double x_m) {
        	return 1.0 / fma(fma(0.041666666666666664, (x_m * x_m), 0.5), (x_m * x_m), 1.0);
        }
        
        x_m = abs(x)
        function code(x_m)
        	return Float64(1.0 / fma(fma(0.041666666666666664, Float64(x_m * x_m), 0.5), Float64(x_m * x_m), 1.0))
        end
        
        x_m = N[Abs[x], $MachinePrecision]
        code[x$95$m_] := N[(1.0 / N[(N[(0.041666666666666664 * N[(x$95$m * x$95$m), $MachinePrecision] + 0.5), $MachinePrecision] * N[(x$95$m * x$95$m), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]
        
        \begin{array}{l}
        x_m = \left|x\right|
        
        \\
        \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x\_m \cdot x\_m, 0.5\right), x\_m \cdot x\_m, 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. lift-/.f64N/A

            \[\leadsto \color{blue}{\frac{2}{e^{x} + e^{-x}}} \]
          2. clear-numN/A

            \[\leadsto \color{blue}{\frac{1}{\frac{e^{x} + e^{-x}}{2}}} \]
          3. lift-+.f64N/A

            \[\leadsto \frac{1}{\frac{\color{blue}{e^{x} + e^{-x}}}{2}} \]
          4. lift-exp.f64N/A

            \[\leadsto \frac{1}{\frac{\color{blue}{e^{x}} + e^{-x}}{2}} \]
          5. lift-exp.f64N/A

            \[\leadsto \frac{1}{\frac{e^{x} + \color{blue}{e^{-x}}}{2}} \]
          6. lift-neg.f64N/A

            \[\leadsto \frac{1}{\frac{e^{x} + e^{\color{blue}{\mathsf{neg}\left(x\right)}}}{2}} \]
          7. cosh-defN/A

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

            \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
          9. 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

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

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

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

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

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

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

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

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

            \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{24}, x \cdot x, \frac{1}{2}\right), \color{blue}{x \cdot x}, 1\right)} \]
          9. lower-*.f6487.7

            \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x \cdot x, 0.5\right), \color{blue}{x \cdot x}, 1\right)} \]
        7. Applied rewrites87.7%

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

        Alternative 7: 88.0% accurate, 6.6× speedup?

        \[\begin{array}{l} x_m = \left|x\right| \\ \frac{1}{\mathsf{fma}\left(0.041666666666666664 \cdot \left(x\_m \cdot x\_m\right), x\_m \cdot x\_m, 1\right)} \end{array} \]
        x_m = (fabs.f64 x)
        (FPCore (x_m)
         :precision binary64
         (/ 1.0 (fma (* 0.041666666666666664 (* x_m x_m)) (* x_m x_m) 1.0)))
        x_m = fabs(x);
        double code(double x_m) {
        	return 1.0 / fma((0.041666666666666664 * (x_m * x_m)), (x_m * x_m), 1.0);
        }
        
        x_m = abs(x)
        function code(x_m)
        	return Float64(1.0 / fma(Float64(0.041666666666666664 * Float64(x_m * x_m)), Float64(x_m * x_m), 1.0))
        end
        
        x_m = N[Abs[x], $MachinePrecision]
        code[x$95$m_] := N[(1.0 / N[(N[(0.041666666666666664 * N[(x$95$m * x$95$m), $MachinePrecision]), $MachinePrecision] * N[(x$95$m * x$95$m), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]
        
        \begin{array}{l}
        x_m = \left|x\right|
        
        \\
        \frac{1}{\mathsf{fma}\left(0.041666666666666664 \cdot \left(x\_m \cdot x\_m\right), x\_m \cdot x\_m, 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. lift-/.f64N/A

            \[\leadsto \color{blue}{\frac{2}{e^{x} + e^{-x}}} \]
          2. clear-numN/A

            \[\leadsto \color{blue}{\frac{1}{\frac{e^{x} + e^{-x}}{2}}} \]
          3. lift-+.f64N/A

            \[\leadsto \frac{1}{\frac{\color{blue}{e^{x} + e^{-x}}}{2}} \]
          4. lift-exp.f64N/A

            \[\leadsto \frac{1}{\frac{\color{blue}{e^{x}} + e^{-x}}{2}} \]
          5. lift-exp.f64N/A

            \[\leadsto \frac{1}{\frac{e^{x} + \color{blue}{e^{-x}}}{2}} \]
          6. lift-neg.f64N/A

            \[\leadsto \frac{1}{\frac{e^{x} + e^{\color{blue}{\mathsf{neg}\left(x\right)}}}{2}} \]
          7. cosh-defN/A

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

            \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
          9. 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

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

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

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

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

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

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

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

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

            \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{24}, x \cdot x, \frac{1}{2}\right), \color{blue}{x \cdot x}, 1\right)} \]
          9. lower-*.f6487.7

            \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x \cdot x, 0.5\right), \color{blue}{x \cdot x}, 1\right)} \]
        7. Applied rewrites87.7%

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

          \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{1}{24} \cdot {x}^{2}, \color{blue}{x} \cdot x, 1\right)} \]
        9. Step-by-step derivation
          1. Applied rewrites87.1%

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

          Alternative 8: 76.4% accurate, 12.1× speedup?

          \[\begin{array}{l} x_m = \left|x\right| \\ \frac{2}{\mathsf{fma}\left(x\_m, x\_m, 2\right)} \end{array} \]
          x_m = (fabs.f64 x)
          (FPCore (x_m) :precision binary64 (/ 2.0 (fma x_m x_m 2.0)))
          x_m = fabs(x);
          double code(double x_m) {
          	return 2.0 / fma(x_m, x_m, 2.0);
          }
          
          x_m = abs(x)
          function code(x_m)
          	return Float64(2.0 / fma(x_m, x_m, 2.0))
          end
          
          x_m = N[Abs[x], $MachinePrecision]
          code[x$95$m_] := N[(2.0 / N[(x$95$m * x$95$m + 2.0), $MachinePrecision]), $MachinePrecision]
          
          \begin{array}{l}
          x_m = \left|x\right|
          
          \\
          \frac{2}{\mathsf{fma}\left(x\_m, x\_m, 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.f6474.6

              \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left(x, x, 2\right)}} \]
          5. Applied rewrites74.6%

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

          Alternative 9: 50.7% accurate, 217.0× speedup?

          \[\begin{array}{l} x_m = \left|x\right| \\ 1 \end{array} \]
          x_m = (fabs.f64 x)
          (FPCore (x_m) :precision binary64 1.0)
          x_m = fabs(x);
          double code(double x_m) {
          	return 1.0;
          }
          
          x_m = abs(x)
          real(8) function code(x_m)
              real(8), intent (in) :: x_m
              code = 1.0d0
          end function
          
          x_m = Math.abs(x);
          public static double code(double x_m) {
          	return 1.0;
          }
          
          x_m = math.fabs(x)
          def code(x_m):
          	return 1.0
          
          x_m = abs(x)
          function code(x_m)
          	return 1.0
          end
          
          x_m = abs(x);
          function tmp = code(x_m)
          	tmp = 1.0;
          end
          
          x_m = N[Abs[x], $MachinePrecision]
          code[x$95$m_] := 1.0
          
          \begin{array}{l}
          x_m = \left|x\right|
          
          \\
          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 rewrites46.6%

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

            Reproduce

            ?
            herbie shell --seed 2024294 
            (FPCore (x)
              :name "Hyperbolic secant"
              :precision binary64
              (/ 2.0 (+ (exp x) (exp (- x)))))