Hyperbolic secant

Percentage Accurate: 100.0% → 100.0%
Time: 11.1s
Alternatives: 10
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 10 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. clear-numN/A

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

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

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

      \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
  4. Applied egg-rr100.0%

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

Alternative 2: 70.9% accurate, 4.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.45:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, -0.08472222222222223, 0.20833333333333334\right), -0.5\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{2}{\left(x \cdot x\right) \cdot \left(\left(x \cdot x\right) \cdot \mathsf{fma}\left(x \cdot x, 0.002777777777777778, 0.08333333333333333\right)\right)}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.45)
   (fma
    (* x x)
    (fma (* x x) (fma (* x x) -0.08472222222222223 0.20833333333333334) -0.5)
    1.0)
   (/
    2.0
    (*
     (* x x)
     (* (* x x) (fma (* x x) 0.002777777777777778 0.08333333333333333))))))
double code(double x) {
	double tmp;
	if (x <= 1.45) {
		tmp = fma((x * x), fma((x * x), fma((x * x), -0.08472222222222223, 0.20833333333333334), -0.5), 1.0);
	} else {
		tmp = 2.0 / ((x * x) * ((x * x) * fma((x * x), 0.002777777777777778, 0.08333333333333333)));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 1.45)
		tmp = fma(Float64(x * x), fma(Float64(x * x), fma(Float64(x * x), -0.08472222222222223, 0.20833333333333334), -0.5), 1.0);
	else
		tmp = Float64(2.0 / Float64(Float64(x * x) * Float64(Float64(x * x) * fma(Float64(x * x), 0.002777777777777778, 0.08333333333333333))));
	end
	return tmp
end
code[x_] := If[LessEqual[x, 1.45], N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * -0.08472222222222223 + 0.20833333333333334), $MachinePrecision] + -0.5), $MachinePrecision] + 1.0), $MachinePrecision], N[(2.0 / N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * 0.002777777777777778 + 0.08333333333333333), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.45:\\
\;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, -0.08472222222222223, 0.20833333333333334\right), -0.5\right), 1\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{2}{\left(x \cdot x\right) \cdot \left(\left(x \cdot x\right) \cdot \mathsf{fma}\left(x \cdot x, 0.002777777777777778, 0.08333333333333333\right)\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.44999999999999996

    1. Initial program 100.0%

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

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

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

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

        \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
    4. Applied egg-rr100.0%

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

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

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

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{-61}{720}, \frac{5}{24}\right), \frac{-1}{2}\right), 1\right) \]
      14. *-lowering-*.f6466.8

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, -0.08472222222222223, 0.20833333333333334\right), -0.5\right), 1\right) \]
    7. Simplified66.8%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, -0.08472222222222223, 0.20833333333333334\right), -0.5\right), 1\right)} \]

    if 1.44999999999999996 < x

    1. Initial program 100.0%

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

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

        \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left({x}^{2}, 1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right), 2\right)}} \]
      3. +-rgt-identityN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\color{blue}{{x}^{2} + 0}, 1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right), 2\right)} \]
      4. unpow2N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\color{blue}{x \cdot x} + 0, 1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right), 2\right)} \]
      5. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(x, x, 0\right)}, 1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right), 2\right)} \]
      6. +-commutativeN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \color{blue}{{x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right) + 1}, 2\right)} \]
      7. unpow2N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \color{blue}{\left(x \cdot x\right)} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right) + 1, 2\right)} \]
      8. associate-*l*N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \color{blue}{x \cdot \left(x \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)} + 1, 2\right)} \]
      9. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \color{blue}{\mathsf{fma}\left(x, x \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right), 1\right)}, 2\right)} \]
      10. +-rgt-identityN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \color{blue}{x \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right) + 0}, 1\right), 2\right)} \]
      11. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, \frac{1}{12} + \frac{1}{360} \cdot {x}^{2}, 0\right)}, 1\right), 2\right)} \]
      12. +-commutativeN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\frac{1}{360} \cdot {x}^{2} + \frac{1}{12}}, 0\right), 1\right), 2\right)} \]
      13. *-commutativeN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{{x}^{2} \cdot \frac{1}{360}} + \frac{1}{12}, 0\right), 1\right), 2\right)} \]
      14. unpow2N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\left(x \cdot x\right)} \cdot \frac{1}{360} + \frac{1}{12}, 0\right), 1\right), 2\right)} \]
      15. associate-*l*N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{x \cdot \left(x \cdot \frac{1}{360}\right)} + \frac{1}{12}, 0\right), 1\right), 2\right)} \]
      16. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, x \cdot \frac{1}{360}, \frac{1}{12}\right)}, 0\right), 1\right), 2\right)} \]
      17. +-rgt-identityN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{360} + 0}, \frac{1}{12}\right), 0\right), 1\right), 2\right)} \]
      18. accelerator-lowering-fma.f6486.3

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.002777777777777778, 0\right)}, 0.08333333333333333\right), 0\right), 1\right), 2\right)} \]
    5. Simplified86.3%

      \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.002777777777777778, 0\right), 0.08333333333333333\right), 0\right), 1\right), 2\right)}} \]
    6. Taylor expanded in x around inf

      \[\leadsto \frac{2}{\color{blue}{{x}^{6} \cdot \left(\frac{1}{360} + \frac{1}{12} \cdot \frac{1}{{x}^{2}}\right)}} \]
    7. Step-by-step derivation
      1. metadata-evalN/A

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

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

        \[\leadsto \frac{2}{\color{blue}{{\left(x \cdot x\right)}^{3}} \cdot \left(\frac{1}{360} + \frac{1}{12} \cdot \frac{1}{{x}^{2}}\right)} \]
      4. unpow2N/A

        \[\leadsto \frac{2}{{\color{blue}{\left({x}^{2}\right)}}^{3} \cdot \left(\frac{1}{360} + \frac{1}{12} \cdot \frac{1}{{x}^{2}}\right)} \]
      5. unpow3N/A

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

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

        \[\leadsto \frac{2}{\left({x}^{\color{blue}{4}} \cdot {x}^{2}\right) \cdot \left(\frac{1}{360} + \frac{1}{12} \cdot \frac{1}{{x}^{2}}\right)} \]
      8. associate-*r*N/A

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

        \[\leadsto \frac{2}{{x}^{4} \cdot \left({x}^{2} \cdot \color{blue}{\left(\frac{1}{12} \cdot \frac{1}{{x}^{2}} + \frac{1}{360}\right)}\right)} \]
      10. distribute-rgt-inN/A

        \[\leadsto \frac{2}{{x}^{4} \cdot \color{blue}{\left(\left(\frac{1}{12} \cdot \frac{1}{{x}^{2}}\right) \cdot {x}^{2} + \frac{1}{360} \cdot {x}^{2}\right)}} \]
      11. associate-*l*N/A

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

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

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

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

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

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

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

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

        \[\leadsto \frac{2}{\color{blue}{\left(x \cdot x\right)} \cdot \left({x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)} \]
    8. Simplified86.3%

      \[\leadsto \frac{2}{\color{blue}{\left(x \cdot x\right) \cdot \left(\left(x \cdot x\right) \cdot \mathsf{fma}\left(x \cdot x, 0.002777777777777778, 0.08333333333333333\right)\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 3: 91.9% accurate, 4.8× speedup?

\[\begin{array}{l} \\ \frac{1}{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, x \cdot 0.001388888888888889, 0.041666666666666664\right), 0.5\right), 1\right)} \end{array} \]
(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(x, Float64(x * fma(x, Float64(x * fma(x, Float64(x * 0.001388888888888889), 0.041666666666666664)), 0.5)), 1.0))
end
code[x_] := N[(1.0 / N[(x * N[(x * N[(x * N[(x * N[(x * N[(x * 0.001388888888888889), $MachinePrecision] + 0.041666666666666664), $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{1}{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, x \cdot 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. clear-numN/A

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

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

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

      \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
  4. Applied egg-rr100.0%

    \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
  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. unpow2N/A

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

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

      \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(x, x \cdot \left(\frac{1}{2} + {x}^{2} \cdot \left(\frac{1}{24} + \frac{1}{720} \cdot {x}^{2}\right)\right), 1\right)}} \]
  7. Simplified94.2%

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

Alternative 4: 70.9% accurate, 5.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.5:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, -0.08472222222222223, 0.20833333333333334\right), -0.5\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{720}{\left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.5)
   (fma
    (* x x)
    (fma (* x x) (fma (* x x) -0.08472222222222223 0.20833333333333334) -0.5)
    1.0)
   (/ 720.0 (* (* x x) (* x (* x (* x x)))))))
double code(double x) {
	double tmp;
	if (x <= 1.5) {
		tmp = fma((x * x), fma((x * x), fma((x * x), -0.08472222222222223, 0.20833333333333334), -0.5), 1.0);
	} else {
		tmp = 720.0 / ((x * x) * (x * (x * (x * x))));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 1.5)
		tmp = fma(Float64(x * x), fma(Float64(x * x), fma(Float64(x * x), -0.08472222222222223, 0.20833333333333334), -0.5), 1.0);
	else
		tmp = Float64(720.0 / Float64(Float64(x * x) * Float64(x * Float64(x * Float64(x * x)))));
	end
	return tmp
end
code[x_] := If[LessEqual[x, 1.5], N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * -0.08472222222222223 + 0.20833333333333334), $MachinePrecision] + -0.5), $MachinePrecision] + 1.0), $MachinePrecision], N[(720.0 / N[(N[(x * x), $MachinePrecision] * N[(x * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.5:\\
\;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, -0.08472222222222223, 0.20833333333333334\right), -0.5\right), 1\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{720}{\left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 1.5

    1. Initial program 100.0%

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

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

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

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

        \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
    4. Applied egg-rr100.0%

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

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

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

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{-61}{720}, \frac{5}{24}\right), \frac{-1}{2}\right), 1\right) \]
      14. *-lowering-*.f6466.8

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(\color{blue}{x \cdot x}, -0.08472222222222223, 0.20833333333333334\right), -0.5\right), 1\right) \]
    7. Simplified66.8%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x \cdot x, -0.08472222222222223, 0.20833333333333334\right), -0.5\right), 1\right)} \]

    if 1.5 < x

    1. Initial program 100.0%

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

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

        \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left({x}^{2}, 1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right), 2\right)}} \]
      3. +-rgt-identityN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\color{blue}{{x}^{2} + 0}, 1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right), 2\right)} \]
      4. unpow2N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\color{blue}{x \cdot x} + 0, 1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right), 2\right)} \]
      5. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(x, x, 0\right)}, 1 + {x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right), 2\right)} \]
      6. +-commutativeN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \color{blue}{{x}^{2} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right) + 1}, 2\right)} \]
      7. unpow2N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \color{blue}{\left(x \cdot x\right)} \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right) + 1, 2\right)} \]
      8. associate-*l*N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \color{blue}{x \cdot \left(x \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right)\right)} + 1, 2\right)} \]
      9. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \color{blue}{\mathsf{fma}\left(x, x \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right), 1\right)}, 2\right)} \]
      10. +-rgt-identityN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \color{blue}{x \cdot \left(\frac{1}{12} + \frac{1}{360} \cdot {x}^{2}\right) + 0}, 1\right), 2\right)} \]
      11. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, \frac{1}{12} + \frac{1}{360} \cdot {x}^{2}, 0\right)}, 1\right), 2\right)} \]
      12. +-commutativeN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\frac{1}{360} \cdot {x}^{2} + \frac{1}{12}}, 0\right), 1\right), 2\right)} \]
      13. *-commutativeN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{{x}^{2} \cdot \frac{1}{360}} + \frac{1}{12}, 0\right), 1\right), 2\right)} \]
      14. unpow2N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\left(x \cdot x\right)} \cdot \frac{1}{360} + \frac{1}{12}, 0\right), 1\right), 2\right)} \]
      15. associate-*l*N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{x \cdot \left(x \cdot \frac{1}{360}\right)} + \frac{1}{12}, 0\right), 1\right), 2\right)} \]
      16. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, x \cdot \frac{1}{360}, \frac{1}{12}\right)}, 0\right), 1\right), 2\right)} \]
      17. +-rgt-identityN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{360} + 0}, \frac{1}{12}\right), 0\right), 1\right), 2\right)} \]
      18. accelerator-lowering-fma.f6486.3

        \[\leadsto \frac{2}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.002777777777777778, 0\right)}, 0.08333333333333333\right), 0\right), 1\right), 2\right)} \]
    5. Simplified86.3%

      \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.002777777777777778, 0\right), 0.08333333333333333\right), 0\right), 1\right), 2\right)}} \]
    6. Taylor expanded in x around inf

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

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

        \[\leadsto \frac{720}{{x}^{\color{blue}{\left(2 \cdot 3\right)}}} \]
      3. pow-sqrN/A

        \[\leadsto \frac{720}{\color{blue}{{x}^{3} \cdot {x}^{3}}} \]
      4. cube-prodN/A

        \[\leadsto \frac{720}{\color{blue}{{\left(x \cdot x\right)}^{3}}} \]
      5. unpow2N/A

        \[\leadsto \frac{720}{{\color{blue}{\left({x}^{2}\right)}}^{3}} \]
      6. cube-unmultN/A

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

        \[\leadsto \frac{720}{{x}^{2} \cdot \color{blue}{{x}^{\left(2 \cdot 2\right)}}} \]
      8. metadata-evalN/A

        \[\leadsto \frac{720}{{x}^{2} \cdot {x}^{\color{blue}{4}}} \]
      9. *-lowering-*.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. *-lowering-*.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. *-lowering-*.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. *-lowering-*.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. *-lowering-*.f6486.3

        \[\leadsto \frac{720}{\left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right)\right)} \]
    8. Simplified86.3%

      \[\leadsto \color{blue}{\frac{720}{\left(x \cdot x\right) \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)}} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 5: 69.1% accurate, 5.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.4:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.20833333333333334, -0.5\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\left(x \cdot x\right) \cdot \mathsf{fma}\left(x, x \cdot 0.041666666666666664, 0.5\right)}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.4)
   (fma (* x x) (fma x (* x 0.20833333333333334) -0.5) 1.0)
   (/ 1.0 (* (* x x) (fma x (* x 0.041666666666666664) 0.5)))))
double code(double x) {
	double tmp;
	if (x <= 1.4) {
		tmp = fma((x * x), fma(x, (x * 0.20833333333333334), -0.5), 1.0);
	} else {
		tmp = 1.0 / ((x * x) * fma(x, (x * 0.041666666666666664), 0.5));
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 1.4)
		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(x, Float64(x * 0.041666666666666664), 0.5)));
	end
	return tmp
end
code[x_] := If[LessEqual[x, 1.4], 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[(x * N[(x * 0.041666666666666664), $MachinePrecision] + 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 1.4:\\
\;\;\;\;\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(x, x \cdot 0.041666666666666664, 0.5\right)}\\


\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. Step-by-step derivation
      1. clear-numN/A

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

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

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

        \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
    4. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
    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. accelerator-lowering-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. *-lowering-*.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. unpow2N/A

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{5}{24}}, \frac{-1}{2}\right), 1\right) \]
      12. *-lowering-*.f6466.7

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot 0.20833333333333334}, -0.5\right), 1\right) \]
    7. Simplified66.7%

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

    if 1.3999999999999999 < x

    1. Initial program 100.0%

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

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

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

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

        \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
    4. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
    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. accelerator-lowering-fma.f64N/A

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left(x, x \cdot \frac{1}{24}, \frac{1}{2}\right)}, 1\right)} \]
      10. *-lowering-*.f6477.7

        \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot 0.041666666666666664}, 0.5\right), 1\right)} \]
    7. Simplified77.7%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{\color{blue}{{x}^{2} \cdot \left(\frac{1}{2} + \frac{1}{24} \cdot {x}^{2}\right)}} \]
    10. Simplified77.7%

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

Alternative 6: 88.1% accurate, 6.4× speedup?

\[\begin{array}{l} \\ \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.041666666666666664, 0.5\right), 1\right)} \end{array} \]
(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(x, Float64(x * 0.041666666666666664), 0.5), 1.0))
end
code[x_] := N[(1.0 / N[(N[(x * x), $MachinePrecision] * N[(x * N[(x * 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, x \cdot 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. clear-numN/A

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

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

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

      \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
  4. Applied egg-rr100.0%

    \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
  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. accelerator-lowering-fma.f64N/A

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

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

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

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

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

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

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

      \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \color{blue}{\mathsf{fma}\left(x, x \cdot \frac{1}{24}, \frac{1}{2}\right)}, 1\right)} \]
    10. *-lowering-*.f6489.0

      \[\leadsto \frac{1}{\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot 0.041666666666666664}, 0.5\right), 1\right)} \]
  7. Simplified89.0%

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

Alternative 7: 69.1% accurate, 6.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.86:\\ \;\;\;\;\mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, x \cdot 0.20833333333333334, -0.5\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{24}{x \cdot \left(x \cdot \left(x \cdot x\right)\right)}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.86)
   (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 (x <= 1.86) {
		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 (x <= 1.86)
		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[x, 1.86], 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}\;x \leq 1.86:\\
\;\;\;\;\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 x < 1.8600000000000001

    1. Initial program 100.0%

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

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

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

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

        \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
    4. Applied egg-rr100.0%

      \[\leadsto \color{blue}{\frac{1}{\cosh x}} \]
    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. accelerator-lowering-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. *-lowering-*.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. unpow2N/A

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{5}{24}}, \frac{-1}{2}\right), 1\right) \]
      12. *-lowering-*.f6466.7

        \[\leadsto \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \color{blue}{x \cdot 0.20833333333333334}, -0.5\right), 1\right) \]
    7. Simplified66.7%

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

    if 1.8600000000000001 < 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. accelerator-lowering-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. +-rgt-identityN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(x, \color{blue}{x \cdot \left(1 + \frac{1}{12} \cdot {x}^{2}\right) + 0}, 2\right)} \]
      6. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 1 + \frac{1}{12} \cdot {x}^{2}, 0\right)}, 2\right)} \]
      7. +-commutativeN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\frac{1}{12} \cdot {x}^{2} + 1}, 0\right), 2\right)} \]
      8. *-commutativeN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{{x}^{2} \cdot \frac{1}{12}} + 1, 0\right), 2\right)} \]
      9. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left({x}^{2}, \frac{1}{12}, 1\right)}, 0\right), 2\right)} \]
      10. +-rgt-identityN/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(\color{blue}{{x}^{2} + 0}, \frac{1}{12}, 1\right), 0\right), 2\right)} \]
      11. unpow2N/A

        \[\leadsto \frac{2}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(\color{blue}{x \cdot x} + 0, \frac{1}{12}, 1\right), 0\right), 2\right)} \]
      12. accelerator-lowering-fma.f6477.7

        \[\leadsto \frac{2}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(\color{blue}{\mathsf{fma}\left(x, x, 0\right)}, 0.08333333333333333, 1\right), 0\right), 2\right)} \]
    5. Simplified77.7%

      \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(\mathsf{fma}\left(x, x, 0\right), 0.08333333333333333, 1\right), 0\right), 2\right)}} \]
    6. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{24}{{x}^{4}}} \]
    7. Step-by-step derivation
      1. /-lowering-/.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. *-lowering-*.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. *-lowering-*.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. *-lowering-*.f6477.7

        \[\leadsto \frac{24}{x \cdot \left(x \cdot \color{blue}{\left(x \cdot x\right)}\right)} \]
    8. Simplified77.7%

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

Alternative 8: 63.3% accurate, 9.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.25:\\ \;\;\;\;\mathsf{fma}\left(-0.5, x \cdot x, 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{2}{x \cdot x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 1.25) (fma -0.5 (* x x) 1.0) (/ 2.0 (* x x))))
double code(double x) {
	double tmp;
	if (x <= 1.25) {
		tmp = fma(-0.5, (x * x), 1.0);
	} else {
		tmp = 2.0 / (x * x);
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (x <= 1.25)
		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[x, 1.25], 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}\;x \leq 1.25:\\
\;\;\;\;\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 x < 1.25

    1. Initial program 100.0%

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

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

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

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

        \[\leadsto \frac{1}{\color{blue}{\cosh x}} \]
    4. Applied egg-rr100.0%

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

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

        \[\leadsto \color{blue}{\frac{-1}{2} \cdot {x}^{2} + 1} \]
      2. accelerator-lowering-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. *-lowering-*.f6466.6

        \[\leadsto \mathsf{fma}\left(-0.5, \color{blue}{x \cdot x}, 1\right) \]
    7. Simplified66.6%

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

    if 1.25 < 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. accelerator-lowering-fma.f6465.5

        \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left(x, x, 2\right)}} \]
    5. Simplified65.5%

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

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

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

        \[\leadsto \frac{2}{\color{blue}{x \cdot x}} \]
      3. *-lowering-*.f6465.5

        \[\leadsto \frac{2}{\color{blue}{x \cdot x}} \]
    8. Simplified65.5%

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

Alternative 9: 76.3% 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. accelerator-lowering-fma.f6479.9

      \[\leadsto \frac{2}{\color{blue}{\mathsf{fma}\left(x, x, 2\right)}} \]
  5. Simplified79.9%

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

Alternative 10: 51.1% 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. Simplified53.0%

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

    Reproduce

    ?
    herbie shell --seed 2024197 
    (FPCore (x)
      :name "Hyperbolic secant"
      :precision binary64
      (/ 2.0 (+ (exp x) (exp (- x)))))