exp2 (problem 3.3.7)

Percentage Accurate: 77.1% → 99.9%
Time: 8.6s
Alternatives: 7
Speedup: 18.7×

Specification

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

\\
\left(e^{x} - 2\right) + 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 7 alternatives:

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

Initial Program: 77.1% accurate, 1.0× speedup?

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

\\
\left(e^{x} - 2\right) + e^{-x}
\end{array}

Alternative 1: 99.9% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\left(e^{x} - 2\right) + e^{-x} \leq 4 \cdot 10^{-7}:\\ \;\;\;\;0.002777777777777778 \cdot {x}^{6} + \left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right) + 1\right)\\ \mathbf{else}:\\ \;\;\;\;2 \cdot \cosh x - 2\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= (+ (- (exp x) 2.0) (exp (- x))) 4e-7)
   (+
    (* 0.002777777777777778 (pow x 6.0))
    (* (* x x) (+ (* 0.08333333333333333 (* x x)) 1.0)))
   (- (* 2.0 (cosh x)) 2.0)))
double code(double x) {
	double tmp;
	if (((exp(x) - 2.0) + exp(-x)) <= 4e-7) {
		tmp = (0.002777777777777778 * pow(x, 6.0)) + ((x * x) * ((0.08333333333333333 * (x * x)) + 1.0));
	} else {
		tmp = (2.0 * cosh(x)) - 2.0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (((exp(x) - 2.0d0) + exp(-x)) <= 4d-7) then
        tmp = (0.002777777777777778d0 * (x ** 6.0d0)) + ((x * x) * ((0.08333333333333333d0 * (x * x)) + 1.0d0))
    else
        tmp = (2.0d0 * cosh(x)) - 2.0d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (((Math.exp(x) - 2.0) + Math.exp(-x)) <= 4e-7) {
		tmp = (0.002777777777777778 * Math.pow(x, 6.0)) + ((x * x) * ((0.08333333333333333 * (x * x)) + 1.0));
	} else {
		tmp = (2.0 * Math.cosh(x)) - 2.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if ((math.exp(x) - 2.0) + math.exp(-x)) <= 4e-7:
		tmp = (0.002777777777777778 * math.pow(x, 6.0)) + ((x * x) * ((0.08333333333333333 * (x * x)) + 1.0))
	else:
		tmp = (2.0 * math.cosh(x)) - 2.0
	return tmp
function code(x)
	tmp = 0.0
	if (Float64(Float64(exp(x) - 2.0) + exp(Float64(-x))) <= 4e-7)
		tmp = Float64(Float64(0.002777777777777778 * (x ^ 6.0)) + Float64(Float64(x * x) * Float64(Float64(0.08333333333333333 * Float64(x * x)) + 1.0)));
	else
		tmp = Float64(Float64(2.0 * cosh(x)) - 2.0);
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (((exp(x) - 2.0) + exp(-x)) <= 4e-7)
		tmp = (0.002777777777777778 * (x ^ 6.0)) + ((x * x) * ((0.08333333333333333 * (x * x)) + 1.0));
	else
		tmp = (2.0 * cosh(x)) - 2.0;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[N[(N[(N[Exp[x], $MachinePrecision] - 2.0), $MachinePrecision] + N[Exp[(-x)], $MachinePrecision]), $MachinePrecision], 4e-7], N[(N[(0.002777777777777778 * N[Power[x, 6.0], $MachinePrecision]), $MachinePrecision] + N[(N[(x * x), $MachinePrecision] * N[(N[(0.08333333333333333 * N[(x * x), $MachinePrecision]), $MachinePrecision] + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(2.0 * N[Cosh[x], $MachinePrecision]), $MachinePrecision] - 2.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\left(e^{x} - 2\right) + e^{-x} \leq 4 \cdot 10^{-7}:\\
\;\;\;\;0.002777777777777778 \cdot {x}^{6} + \left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right) + 1\right)\\

\mathbf{else}:\\
\;\;\;\;2 \cdot \cosh x - 2\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (-.f64 (exp.f64 x) 2) (exp.f64 (neg.f64 x))) < 3.9999999999999998e-7

    1. Initial program 64.0%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. +-commutative64.0%

        \[\leadsto \color{blue}{e^{-x} + \left(e^{x} - 2\right)} \]
      2. sub-neg64.0%

        \[\leadsto e^{-x} + \color{blue}{\left(e^{x} + \left(-2\right)\right)} \]
      3. +-commutative64.0%

        \[\leadsto e^{-x} + \color{blue}{\left(\left(-2\right) + e^{x}\right)} \]
      4. associate-+l+64.0%

        \[\leadsto \color{blue}{\left(e^{-x} + \left(-2\right)\right) + e^{x}} \]
      5. sub-neg64.0%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right)} + e^{x} \]
      6. remove-double-neg64.0%

        \[\leadsto \left(e^{-x} - 2\right) + \color{blue}{\left(-\left(-e^{x}\right)\right)} \]
      7. sub-neg64.0%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right) - \left(-e^{x}\right)} \]
      8. neg-sub064.0%

        \[\leadsto \left(e^{-x} - 2\right) - \color{blue}{\left(0 - e^{x}\right)} \]
      9. associate--r-64.0%

        \[\leadsto \color{blue}{\left(\left(e^{-x} - 2\right) - 0\right) + e^{x}} \]
      10. +-commutative64.0%

        \[\leadsto \color{blue}{e^{x} + \left(\left(e^{-x} - 2\right) - 0\right)} \]
      11. --rgt-identity64.0%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} - 2\right)} \]
      12. sub-neg64.0%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      13. metadata-eval64.0%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified64.0%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Taylor expanded in x around 0 100.0%

      \[\leadsto \color{blue}{0.002777777777777778 \cdot {x}^{6} + \left(0.08333333333333333 \cdot {x}^{4} + {x}^{2}\right)} \]
    5. Step-by-step derivation
      1. metadata-eval100.0%

        \[\leadsto 0.002777777777777778 \cdot {x}^{6} + \left(0.08333333333333333 \cdot {x}^{\color{blue}{\left(2 + 2\right)}} + {x}^{2}\right) \]
      2. pow-prod-up100.0%

        \[\leadsto 0.002777777777777778 \cdot {x}^{6} + \left(0.08333333333333333 \cdot \color{blue}{\left({x}^{2} \cdot {x}^{2}\right)} + {x}^{2}\right) \]
      3. associate-*r*100.0%

        \[\leadsto 0.002777777777777778 \cdot {x}^{6} + \left(\color{blue}{\left(0.08333333333333333 \cdot {x}^{2}\right) \cdot {x}^{2}} + {x}^{2}\right) \]
      4. distribute-lft1-in100.0%

        \[\leadsto 0.002777777777777778 \cdot {x}^{6} + \color{blue}{\left(0.08333333333333333 \cdot {x}^{2} + 1\right) \cdot {x}^{2}} \]
      5. unpow2100.0%

        \[\leadsto 0.002777777777777778 \cdot {x}^{6} + \left(0.08333333333333333 \cdot \color{blue}{\left(x \cdot x\right)} + 1\right) \cdot {x}^{2} \]
      6. unpow2100.0%

        \[\leadsto 0.002777777777777778 \cdot {x}^{6} + \left(0.08333333333333333 \cdot \left(x \cdot x\right) + 1\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
    6. Applied egg-rr100.0%

      \[\leadsto 0.002777777777777778 \cdot {x}^{6} + \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right) + 1\right) \cdot \left(x \cdot x\right)} \]

    if 3.9999999999999998e-7 < (+.f64 (-.f64 (exp.f64 x) 2) (exp.f64 (neg.f64 x)))

    1. Initial program 100.0%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \color{blue}{e^{-x} + \left(e^{x} - 2\right)} \]
      2. sub-neg100.0%

        \[\leadsto e^{-x} + \color{blue}{\left(e^{x} + \left(-2\right)\right)} \]
      3. +-commutative100.0%

        \[\leadsto e^{-x} + \color{blue}{\left(\left(-2\right) + e^{x}\right)} \]
      4. associate-+l+100.0%

        \[\leadsto \color{blue}{\left(e^{-x} + \left(-2\right)\right) + e^{x}} \]
      5. sub-neg100.0%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right)} + e^{x} \]
      6. remove-double-neg100.0%

        \[\leadsto \left(e^{-x} - 2\right) + \color{blue}{\left(-\left(-e^{x}\right)\right)} \]
      7. sub-neg100.0%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right) - \left(-e^{x}\right)} \]
      8. neg-sub0100.0%

        \[\leadsto \left(e^{-x} - 2\right) - \color{blue}{\left(0 - e^{x}\right)} \]
      9. associate--r-100.0%

        \[\leadsto \color{blue}{\left(\left(e^{-x} - 2\right) - 0\right) + e^{x}} \]
      10. +-commutative100.0%

        \[\leadsto \color{blue}{e^{x} + \left(\left(e^{-x} - 2\right) - 0\right)} \]
      11. --rgt-identity100.0%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} - 2\right)} \]
      12. sub-neg100.0%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      13. metadata-eval100.0%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Step-by-step derivation
      1. associate-+r+100.0%

        \[\leadsto \color{blue}{\left(e^{x} + e^{-x}\right) + -2} \]
      2. metadata-eval100.0%

        \[\leadsto \left(e^{x} + e^{-x}\right) + \color{blue}{\left(-2\right)} \]
      3. sub-neg100.0%

        \[\leadsto \color{blue}{\left(e^{x} + e^{-x}\right) - 2} \]
      4. cosh-undef100.0%

        \[\leadsto \color{blue}{2 \cdot \cosh x} - 2 \]
    5. Applied egg-rr100.0%

      \[\leadsto \color{blue}{2 \cdot \cosh x - 2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification100.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\left(e^{x} - 2\right) + e^{-x} \leq 4 \cdot 10^{-7}:\\ \;\;\;\;0.002777777777777778 \cdot {x}^{6} + \left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right) + 1\right)\\ \mathbf{else}:\\ \;\;\;\;2 \cdot \cosh x - 2\\ \end{array} \]

Alternative 2: 94.0% accurate, 1.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 0.006:\\ \;\;\;\;\left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right) - -1\right)\\ \mathbf{else}:\\ \;\;\;\;2 \cdot \cosh x - 2\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 0.006)
   (* (* x x) (- (* 0.08333333333333333 (* x x)) -1.0))
   (- (* 2.0 (cosh x)) 2.0)))
double code(double x) {
	double tmp;
	if (x <= 0.006) {
		tmp = (x * x) * ((0.08333333333333333 * (x * x)) - -1.0);
	} else {
		tmp = (2.0 * cosh(x)) - 2.0;
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 0.006d0) then
        tmp = (x * x) * ((0.08333333333333333d0 * (x * x)) - (-1.0d0))
    else
        tmp = (2.0d0 * cosh(x)) - 2.0d0
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 0.006) {
		tmp = (x * x) * ((0.08333333333333333 * (x * x)) - -1.0);
	} else {
		tmp = (2.0 * Math.cosh(x)) - 2.0;
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 0.006:
		tmp = (x * x) * ((0.08333333333333333 * (x * x)) - -1.0)
	else:
		tmp = (2.0 * math.cosh(x)) - 2.0
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 0.006)
		tmp = Float64(Float64(x * x) * Float64(Float64(0.08333333333333333 * Float64(x * x)) - -1.0));
	else
		tmp = Float64(Float64(2.0 * cosh(x)) - 2.0);
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 0.006)
		tmp = (x * x) * ((0.08333333333333333 * (x * x)) - -1.0);
	else
		tmp = (2.0 * cosh(x)) - 2.0;
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 0.006], N[(N[(x * x), $MachinePrecision] * N[(N[(0.08333333333333333 * N[(x * x), $MachinePrecision]), $MachinePrecision] - -1.0), $MachinePrecision]), $MachinePrecision], N[(N[(2.0 * N[Cosh[x], $MachinePrecision]), $MachinePrecision] - 2.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 0.006:\\
\;\;\;\;\left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right) - -1\right)\\

\mathbf{else}:\\
\;\;\;\;2 \cdot \cosh x - 2\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 0.0060000000000000001

    1. Initial program 76.8%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. +-commutative76.8%

        \[\leadsto \color{blue}{e^{-x} + \left(e^{x} - 2\right)} \]
      2. sub-neg76.8%

        \[\leadsto e^{-x} + \color{blue}{\left(e^{x} + \left(-2\right)\right)} \]
      3. +-commutative76.8%

        \[\leadsto e^{-x} + \color{blue}{\left(\left(-2\right) + e^{x}\right)} \]
      4. associate-+l+76.8%

        \[\leadsto \color{blue}{\left(e^{-x} + \left(-2\right)\right) + e^{x}} \]
      5. sub-neg76.8%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right)} + e^{x} \]
      6. remove-double-neg76.8%

        \[\leadsto \left(e^{-x} - 2\right) + \color{blue}{\left(-\left(-e^{x}\right)\right)} \]
      7. sub-neg76.8%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right) - \left(-e^{x}\right)} \]
      8. neg-sub076.8%

        \[\leadsto \left(e^{-x} - 2\right) - \color{blue}{\left(0 - e^{x}\right)} \]
      9. associate--r-76.8%

        \[\leadsto \color{blue}{\left(\left(e^{-x} - 2\right) - 0\right) + e^{x}} \]
      10. +-commutative76.8%

        \[\leadsto \color{blue}{e^{x} + \left(\left(e^{-x} - 2\right) - 0\right)} \]
      11. --rgt-identity76.8%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} - 2\right)} \]
      12. sub-neg76.8%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      13. metadata-eval76.8%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified76.8%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Taylor expanded in x around 0 92.2%

      \[\leadsto \color{blue}{0.08333333333333333 \cdot {x}^{4} + {x}^{2}} \]
    5. Step-by-step derivation
      1. fma-def92.2%

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, {x}^{4}, {x}^{2}\right)} \]
      2. unpow292.2%

        \[\leadsto \mathsf{fma}\left(0.08333333333333333, {x}^{4}, \color{blue}{x \cdot x}\right) \]
    6. Simplified92.2%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, {x}^{4}, x \cdot x\right)} \]
    7. Step-by-step derivation
      1. fma-udef92.2%

        \[\leadsto \color{blue}{0.08333333333333333 \cdot {x}^{4} + x \cdot x} \]
      2. unpow292.2%

        \[\leadsto 0.08333333333333333 \cdot {x}^{4} + \color{blue}{{x}^{2}} \]
      3. +-commutative92.2%

        \[\leadsto \color{blue}{{x}^{2} + 0.08333333333333333 \cdot {x}^{4}} \]
      4. unpow292.2%

        \[\leadsto \color{blue}{x \cdot x} + 0.08333333333333333 \cdot {x}^{4} \]
    8. Applied egg-rr92.2%

      \[\leadsto \color{blue}{x \cdot x + 0.08333333333333333 \cdot {x}^{4}} \]
    9. Step-by-step derivation
      1. metadata-eval92.2%

        \[\leadsto x \cdot x + 0.08333333333333333 \cdot {x}^{\color{blue}{\left(2 \cdot 2\right)}} \]
      2. pow-sqr92.2%

        \[\leadsto x \cdot x + 0.08333333333333333 \cdot \color{blue}{\left({x}^{2} \cdot {x}^{2}\right)} \]
      3. pow292.2%

        \[\leadsto x \cdot x + 0.08333333333333333 \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {x}^{2}\right) \]
      4. pow292.2%

        \[\leadsto x \cdot x + 0.08333333333333333 \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{\left(x \cdot x\right)}\right) \]
      5. associate-*r*92.2%

        \[\leadsto x \cdot x + \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)} \]
      6. distribute-rgt1-in92.2%

        \[\leadsto \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right) + 1\right) \cdot \left(x \cdot x\right)} \]
      7. fma-def92.2%

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, x \cdot x, 1\right)} \cdot \left(x \cdot x\right) \]
    10. Applied egg-rr92.2%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, x \cdot x, 1\right) \cdot \left(x \cdot x\right)} \]
    11. Step-by-step derivation
      1. metadata-eval92.2%

        \[\leadsto \mathsf{fma}\left(0.08333333333333333, x \cdot x, \color{blue}{--1}\right) \cdot \left(x \cdot x\right) \]
      2. metadata-eval92.2%

        \[\leadsto \mathsf{fma}\left(0.08333333333333333, x \cdot x, -\color{blue}{\left(-1\right)}\right) \cdot \left(x \cdot x\right) \]
      3. fma-neg92.2%

        \[\leadsto \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right) - \left(-1\right)\right)} \cdot \left(x \cdot x\right) \]
      4. metadata-eval92.2%

        \[\leadsto \left(0.08333333333333333 \cdot \left(x \cdot x\right) - \color{blue}{-1}\right) \cdot \left(x \cdot x\right) \]
    12. Applied egg-rr92.2%

      \[\leadsto \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right) - -1\right)} \cdot \left(x \cdot x\right) \]

    if 0.0060000000000000001 < x

    1. Initial program 100.0%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \color{blue}{e^{-x} + \left(e^{x} - 2\right)} \]
      2. sub-neg100.0%

        \[\leadsto e^{-x} + \color{blue}{\left(e^{x} + \left(-2\right)\right)} \]
      3. +-commutative100.0%

        \[\leadsto e^{-x} + \color{blue}{\left(\left(-2\right) + e^{x}\right)} \]
      4. associate-+l+100.0%

        \[\leadsto \color{blue}{\left(e^{-x} + \left(-2\right)\right) + e^{x}} \]
      5. sub-neg100.0%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right)} + e^{x} \]
      6. remove-double-neg100.0%

        \[\leadsto \left(e^{-x} - 2\right) + \color{blue}{\left(-\left(-e^{x}\right)\right)} \]
      7. sub-neg100.0%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right) - \left(-e^{x}\right)} \]
      8. neg-sub0100.0%

        \[\leadsto \left(e^{-x} - 2\right) - \color{blue}{\left(0 - e^{x}\right)} \]
      9. associate--r-100.0%

        \[\leadsto \color{blue}{\left(\left(e^{-x} - 2\right) - 0\right) + e^{x}} \]
      10. +-commutative100.0%

        \[\leadsto \color{blue}{e^{x} + \left(\left(e^{-x} - 2\right) - 0\right)} \]
      11. --rgt-identity100.0%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} - 2\right)} \]
      12. sub-neg100.0%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      13. metadata-eval100.0%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Step-by-step derivation
      1. associate-+r+100.0%

        \[\leadsto \color{blue}{\left(e^{x} + e^{-x}\right) + -2} \]
      2. metadata-eval100.0%

        \[\leadsto \left(e^{x} + e^{-x}\right) + \color{blue}{\left(-2\right)} \]
      3. sub-neg100.0%

        \[\leadsto \color{blue}{\left(e^{x} + e^{-x}\right) - 2} \]
      4. cosh-undef100.0%

        \[\leadsto \color{blue}{2 \cdot \cosh x} - 2 \]
    5. Applied egg-rr100.0%

      \[\leadsto \color{blue}{2 \cdot \cosh x - 2} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification94.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 0.006:\\ \;\;\;\;\left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right) - -1\right)\\ \mathbf{else}:\\ \;\;\;\;2 \cdot \cosh x - 2\\ \end{array} \]

Alternative 3: 93.9% accurate, 2.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 2.6:\\ \;\;\;\;\left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right) - -1\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{expm1}\left(x\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 2.6)
   (* (* x x) (- (* 0.08333333333333333 (* x x)) -1.0))
   (expm1 x)))
double code(double x) {
	double tmp;
	if (x <= 2.6) {
		tmp = (x * x) * ((0.08333333333333333 * (x * x)) - -1.0);
	} else {
		tmp = expm1(x);
	}
	return tmp;
}
public static double code(double x) {
	double tmp;
	if (x <= 2.6) {
		tmp = (x * x) * ((0.08333333333333333 * (x * x)) - -1.0);
	} else {
		tmp = Math.expm1(x);
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 2.6:
		tmp = (x * x) * ((0.08333333333333333 * (x * x)) - -1.0)
	else:
		tmp = math.expm1(x)
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 2.6)
		tmp = Float64(Float64(x * x) * Float64(Float64(0.08333333333333333 * Float64(x * x)) - -1.0));
	else
		tmp = expm1(x);
	end
	return tmp
end
code[x_] := If[LessEqual[x, 2.6], N[(N[(x * x), $MachinePrecision] * N[(N[(0.08333333333333333 * N[(x * x), $MachinePrecision]), $MachinePrecision] - -1.0), $MachinePrecision]), $MachinePrecision], N[(Exp[x] - 1), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 2.6:\\
\;\;\;\;\left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right) - -1\right)\\

\mathbf{else}:\\
\;\;\;\;\mathsf{expm1}\left(x\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 2.60000000000000009

    1. Initial program 76.8%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. +-commutative76.8%

        \[\leadsto \color{blue}{e^{-x} + \left(e^{x} - 2\right)} \]
      2. sub-neg76.8%

        \[\leadsto e^{-x} + \color{blue}{\left(e^{x} + \left(-2\right)\right)} \]
      3. +-commutative76.8%

        \[\leadsto e^{-x} + \color{blue}{\left(\left(-2\right) + e^{x}\right)} \]
      4. associate-+l+76.8%

        \[\leadsto \color{blue}{\left(e^{-x} + \left(-2\right)\right) + e^{x}} \]
      5. sub-neg76.8%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right)} + e^{x} \]
      6. remove-double-neg76.8%

        \[\leadsto \left(e^{-x} - 2\right) + \color{blue}{\left(-\left(-e^{x}\right)\right)} \]
      7. sub-neg76.8%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right) - \left(-e^{x}\right)} \]
      8. neg-sub076.8%

        \[\leadsto \left(e^{-x} - 2\right) - \color{blue}{\left(0 - e^{x}\right)} \]
      9. associate--r-76.8%

        \[\leadsto \color{blue}{\left(\left(e^{-x} - 2\right) - 0\right) + e^{x}} \]
      10. +-commutative76.8%

        \[\leadsto \color{blue}{e^{x} + \left(\left(e^{-x} - 2\right) - 0\right)} \]
      11. --rgt-identity76.8%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} - 2\right)} \]
      12. sub-neg76.8%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      13. metadata-eval76.8%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified76.8%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Taylor expanded in x around 0 92.2%

      \[\leadsto \color{blue}{0.08333333333333333 \cdot {x}^{4} + {x}^{2}} \]
    5. Step-by-step derivation
      1. fma-def92.2%

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, {x}^{4}, {x}^{2}\right)} \]
      2. unpow292.2%

        \[\leadsto \mathsf{fma}\left(0.08333333333333333, {x}^{4}, \color{blue}{x \cdot x}\right) \]
    6. Simplified92.2%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, {x}^{4}, x \cdot x\right)} \]
    7. Step-by-step derivation
      1. fma-udef92.2%

        \[\leadsto \color{blue}{0.08333333333333333 \cdot {x}^{4} + x \cdot x} \]
      2. unpow292.2%

        \[\leadsto 0.08333333333333333 \cdot {x}^{4} + \color{blue}{{x}^{2}} \]
      3. +-commutative92.2%

        \[\leadsto \color{blue}{{x}^{2} + 0.08333333333333333 \cdot {x}^{4}} \]
      4. unpow292.2%

        \[\leadsto \color{blue}{x \cdot x} + 0.08333333333333333 \cdot {x}^{4} \]
    8. Applied egg-rr92.2%

      \[\leadsto \color{blue}{x \cdot x + 0.08333333333333333 \cdot {x}^{4}} \]
    9. Step-by-step derivation
      1. metadata-eval92.2%

        \[\leadsto x \cdot x + 0.08333333333333333 \cdot {x}^{\color{blue}{\left(2 \cdot 2\right)}} \]
      2. pow-sqr92.2%

        \[\leadsto x \cdot x + 0.08333333333333333 \cdot \color{blue}{\left({x}^{2} \cdot {x}^{2}\right)} \]
      3. pow292.2%

        \[\leadsto x \cdot x + 0.08333333333333333 \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {x}^{2}\right) \]
      4. pow292.2%

        \[\leadsto x \cdot x + 0.08333333333333333 \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{\left(x \cdot x\right)}\right) \]
      5. associate-*r*92.2%

        \[\leadsto x \cdot x + \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)} \]
      6. distribute-rgt1-in92.2%

        \[\leadsto \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right) + 1\right) \cdot \left(x \cdot x\right)} \]
      7. fma-def92.2%

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, x \cdot x, 1\right)} \cdot \left(x \cdot x\right) \]
    10. Applied egg-rr92.2%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, x \cdot x, 1\right) \cdot \left(x \cdot x\right)} \]
    11. Step-by-step derivation
      1. metadata-eval92.2%

        \[\leadsto \mathsf{fma}\left(0.08333333333333333, x \cdot x, \color{blue}{--1}\right) \cdot \left(x \cdot x\right) \]
      2. metadata-eval92.2%

        \[\leadsto \mathsf{fma}\left(0.08333333333333333, x \cdot x, -\color{blue}{\left(-1\right)}\right) \cdot \left(x \cdot x\right) \]
      3. fma-neg92.2%

        \[\leadsto \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right) - \left(-1\right)\right)} \cdot \left(x \cdot x\right) \]
      4. metadata-eval92.2%

        \[\leadsto \left(0.08333333333333333 \cdot \left(x \cdot x\right) - \color{blue}{-1}\right) \cdot \left(x \cdot x\right) \]
    12. Applied egg-rr92.2%

      \[\leadsto \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right) - -1\right)} \cdot \left(x \cdot x\right) \]

    if 2.60000000000000009 < x

    1. Initial program 100.0%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \color{blue}{e^{-x} + \left(e^{x} - 2\right)} \]
      2. sub-neg100.0%

        \[\leadsto e^{-x} + \color{blue}{\left(e^{x} + \left(-2\right)\right)} \]
      3. +-commutative100.0%

        \[\leadsto e^{-x} + \color{blue}{\left(\left(-2\right) + e^{x}\right)} \]
      4. associate-+l+100.0%

        \[\leadsto \color{blue}{\left(e^{-x} + \left(-2\right)\right) + e^{x}} \]
      5. sub-neg100.0%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right)} + e^{x} \]
      6. remove-double-neg100.0%

        \[\leadsto \left(e^{-x} - 2\right) + \color{blue}{\left(-\left(-e^{x}\right)\right)} \]
      7. sub-neg100.0%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right) - \left(-e^{x}\right)} \]
      8. neg-sub0100.0%

        \[\leadsto \left(e^{-x} - 2\right) - \color{blue}{\left(0 - e^{x}\right)} \]
      9. associate--r-100.0%

        \[\leadsto \color{blue}{\left(\left(e^{-x} - 2\right) - 0\right) + e^{x}} \]
      10. +-commutative100.0%

        \[\leadsto \color{blue}{e^{x} + \left(\left(e^{-x} - 2\right) - 0\right)} \]
      11. --rgt-identity100.0%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} - 2\right)} \]
      12. sub-neg100.0%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      13. metadata-eval100.0%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Taylor expanded in x around 0 99.1%

      \[\leadsto e^{x} + \color{blue}{-1} \]
    5. Taylor expanded in x around inf 99.1%

      \[\leadsto \color{blue}{e^{x} - 1} \]
    6. Step-by-step derivation
      1. expm1-def99.1%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(x\right)} \]
    7. Simplified99.1%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(x\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification94.2%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 2.6:\\ \;\;\;\;\left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right) - -1\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{expm1}\left(x\right)\\ \end{array} \]

Alternative 4: 81.3% accurate, 18.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 3.5:\\ \;\;\;\;x \cdot x\\ \mathbf{else}:\\ \;\;\;\;\left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right)\right)\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= x 3.5) (* x x) (* (* x x) (* 0.08333333333333333 (* x x)))))
double code(double x) {
	double tmp;
	if (x <= 3.5) {
		tmp = x * x;
	} else {
		tmp = (x * x) * (0.08333333333333333 * (x * x));
	}
	return tmp;
}
real(8) function code(x)
    real(8), intent (in) :: x
    real(8) :: tmp
    if (x <= 3.5d0) then
        tmp = x * x
    else
        tmp = (x * x) * (0.08333333333333333d0 * (x * x))
    end if
    code = tmp
end function
public static double code(double x) {
	double tmp;
	if (x <= 3.5) {
		tmp = x * x;
	} else {
		tmp = (x * x) * (0.08333333333333333 * (x * x));
	}
	return tmp;
}
def code(x):
	tmp = 0
	if x <= 3.5:
		tmp = x * x
	else:
		tmp = (x * x) * (0.08333333333333333 * (x * x))
	return tmp
function code(x)
	tmp = 0.0
	if (x <= 3.5)
		tmp = Float64(x * x);
	else
		tmp = Float64(Float64(x * x) * Float64(0.08333333333333333 * Float64(x * x)));
	end
	return tmp
end
function tmp_2 = code(x)
	tmp = 0.0;
	if (x <= 3.5)
		tmp = x * x;
	else
		tmp = (x * x) * (0.08333333333333333 * (x * x));
	end
	tmp_2 = tmp;
end
code[x_] := If[LessEqual[x, 3.5], N[(x * x), $MachinePrecision], N[(N[(x * x), $MachinePrecision] * N[(0.08333333333333333 * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \leq 3.5:\\
\;\;\;\;x \cdot x\\

\mathbf{else}:\\
\;\;\;\;\left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if x < 3.5

    1. Initial program 76.8%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. +-commutative76.8%

        \[\leadsto \color{blue}{e^{-x} + \left(e^{x} - 2\right)} \]
      2. sub-neg76.8%

        \[\leadsto e^{-x} + \color{blue}{\left(e^{x} + \left(-2\right)\right)} \]
      3. +-commutative76.8%

        \[\leadsto e^{-x} + \color{blue}{\left(\left(-2\right) + e^{x}\right)} \]
      4. associate-+l+76.8%

        \[\leadsto \color{blue}{\left(e^{-x} + \left(-2\right)\right) + e^{x}} \]
      5. sub-neg76.8%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right)} + e^{x} \]
      6. remove-double-neg76.8%

        \[\leadsto \left(e^{-x} - 2\right) + \color{blue}{\left(-\left(-e^{x}\right)\right)} \]
      7. sub-neg76.8%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right) - \left(-e^{x}\right)} \]
      8. neg-sub076.8%

        \[\leadsto \left(e^{-x} - 2\right) - \color{blue}{\left(0 - e^{x}\right)} \]
      9. associate--r-76.8%

        \[\leadsto \color{blue}{\left(\left(e^{-x} - 2\right) - 0\right) + e^{x}} \]
      10. +-commutative76.8%

        \[\leadsto \color{blue}{e^{x} + \left(\left(e^{-x} - 2\right) - 0\right)} \]
      11. --rgt-identity76.8%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} - 2\right)} \]
      12. sub-neg76.8%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      13. metadata-eval76.8%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified76.8%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Taylor expanded in x around 0 81.8%

      \[\leadsto \color{blue}{{x}^{2}} \]
    5. Step-by-step derivation
      1. unpow281.8%

        \[\leadsto \color{blue}{x \cdot x} \]
    6. Simplified81.8%

      \[\leadsto \color{blue}{x \cdot x} \]

    if 3.5 < x

    1. Initial program 100.0%

      \[\left(e^{x} - 2\right) + e^{-x} \]
    2. Step-by-step derivation
      1. +-commutative100.0%

        \[\leadsto \color{blue}{e^{-x} + \left(e^{x} - 2\right)} \]
      2. sub-neg100.0%

        \[\leadsto e^{-x} + \color{blue}{\left(e^{x} + \left(-2\right)\right)} \]
      3. +-commutative100.0%

        \[\leadsto e^{-x} + \color{blue}{\left(\left(-2\right) + e^{x}\right)} \]
      4. associate-+l+100.0%

        \[\leadsto \color{blue}{\left(e^{-x} + \left(-2\right)\right) + e^{x}} \]
      5. sub-neg100.0%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right)} + e^{x} \]
      6. remove-double-neg100.0%

        \[\leadsto \left(e^{-x} - 2\right) + \color{blue}{\left(-\left(-e^{x}\right)\right)} \]
      7. sub-neg100.0%

        \[\leadsto \color{blue}{\left(e^{-x} - 2\right) - \left(-e^{x}\right)} \]
      8. neg-sub0100.0%

        \[\leadsto \left(e^{-x} - 2\right) - \color{blue}{\left(0 - e^{x}\right)} \]
      9. associate--r-100.0%

        \[\leadsto \color{blue}{\left(\left(e^{-x} - 2\right) - 0\right) + e^{x}} \]
      10. +-commutative100.0%

        \[\leadsto \color{blue}{e^{x} + \left(\left(e^{-x} - 2\right) - 0\right)} \]
      11. --rgt-identity100.0%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} - 2\right)} \]
      12. sub-neg100.0%

        \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
      13. metadata-eval100.0%

        \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
    4. Taylor expanded in x around 0 67.6%

      \[\leadsto \color{blue}{0.08333333333333333 \cdot {x}^{4} + {x}^{2}} \]
    5. Step-by-step derivation
      1. fma-def67.6%

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, {x}^{4}, {x}^{2}\right)} \]
      2. unpow267.6%

        \[\leadsto \mathsf{fma}\left(0.08333333333333333, {x}^{4}, \color{blue}{x \cdot x}\right) \]
    6. Simplified67.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, {x}^{4}, x \cdot x\right)} \]
    7. Step-by-step derivation
      1. fma-udef67.6%

        \[\leadsto \color{blue}{0.08333333333333333 \cdot {x}^{4} + x \cdot x} \]
      2. unpow267.6%

        \[\leadsto 0.08333333333333333 \cdot {x}^{4} + \color{blue}{{x}^{2}} \]
      3. +-commutative67.6%

        \[\leadsto \color{blue}{{x}^{2} + 0.08333333333333333 \cdot {x}^{4}} \]
      4. unpow267.6%

        \[\leadsto \color{blue}{x \cdot x} + 0.08333333333333333 \cdot {x}^{4} \]
    8. Applied egg-rr67.6%

      \[\leadsto \color{blue}{x \cdot x + 0.08333333333333333 \cdot {x}^{4}} \]
    9. Step-by-step derivation
      1. metadata-eval67.6%

        \[\leadsto x \cdot x + 0.08333333333333333 \cdot {x}^{\color{blue}{\left(2 \cdot 2\right)}} \]
      2. pow-sqr67.6%

        \[\leadsto x \cdot x + 0.08333333333333333 \cdot \color{blue}{\left({x}^{2} \cdot {x}^{2}\right)} \]
      3. pow267.6%

        \[\leadsto x \cdot x + 0.08333333333333333 \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {x}^{2}\right) \]
      4. pow267.6%

        \[\leadsto x \cdot x + 0.08333333333333333 \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{\left(x \cdot x\right)}\right) \]
      5. associate-*r*67.6%

        \[\leadsto x \cdot x + \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)} \]
      6. distribute-rgt1-in67.6%

        \[\leadsto \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right) + 1\right) \cdot \left(x \cdot x\right)} \]
      7. fma-def67.6%

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, x \cdot x, 1\right)} \cdot \left(x \cdot x\right) \]
    10. Applied egg-rr67.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, x \cdot x, 1\right) \cdot \left(x \cdot x\right)} \]
    11. Taylor expanded in x around inf 67.6%

      \[\leadsto \color{blue}{\left(0.08333333333333333 \cdot {x}^{2}\right)} \cdot \left(x \cdot x\right) \]
    12. Step-by-step derivation
      1. unpow267.6%

        \[\leadsto \left(0.08333333333333333 \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot \left(x \cdot x\right) \]
    13. Simplified67.6%

      \[\leadsto \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right)\right)} \cdot \left(x \cdot x\right) \]
  3. Recombined 2 regimes into one program.
  4. Final simplification77.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;x \leq 3.5:\\ \;\;\;\;x \cdot x\\ \mathbf{else}:\\ \;\;\;\;\left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right)\right)\\ \end{array} \]

Alternative 5: 87.8% accurate, 18.7× speedup?

\[\begin{array}{l} \\ \left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right) - -1\right) \end{array} \]
(FPCore (x)
 :precision binary64
 (* (* x x) (- (* 0.08333333333333333 (* x x)) -1.0)))
double code(double x) {
	return (x * x) * ((0.08333333333333333 * (x * x)) - -1.0);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = (x * x) * ((0.08333333333333333d0 * (x * x)) - (-1.0d0))
end function
public static double code(double x) {
	return (x * x) * ((0.08333333333333333 * (x * x)) - -1.0);
}
def code(x):
	return (x * x) * ((0.08333333333333333 * (x * x)) - -1.0)
function code(x)
	return Float64(Float64(x * x) * Float64(Float64(0.08333333333333333 * Float64(x * x)) - -1.0))
end
function tmp = code(x)
	tmp = (x * x) * ((0.08333333333333333 * (x * x)) - -1.0);
end
code[x_] := N[(N[(x * x), $MachinePrecision] * N[(N[(0.08333333333333333 * N[(x * x), $MachinePrecision]), $MachinePrecision] - -1.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right) - -1\right)
\end{array}
Derivation
  1. Initial program 83.4%

    \[\left(e^{x} - 2\right) + e^{-x} \]
  2. Step-by-step derivation
    1. +-commutative83.4%

      \[\leadsto \color{blue}{e^{-x} + \left(e^{x} - 2\right)} \]
    2. sub-neg83.4%

      \[\leadsto e^{-x} + \color{blue}{\left(e^{x} + \left(-2\right)\right)} \]
    3. +-commutative83.4%

      \[\leadsto e^{-x} + \color{blue}{\left(\left(-2\right) + e^{x}\right)} \]
    4. associate-+l+83.4%

      \[\leadsto \color{blue}{\left(e^{-x} + \left(-2\right)\right) + e^{x}} \]
    5. sub-neg83.4%

      \[\leadsto \color{blue}{\left(e^{-x} - 2\right)} + e^{x} \]
    6. remove-double-neg83.4%

      \[\leadsto \left(e^{-x} - 2\right) + \color{blue}{\left(-\left(-e^{x}\right)\right)} \]
    7. sub-neg83.4%

      \[\leadsto \color{blue}{\left(e^{-x} - 2\right) - \left(-e^{x}\right)} \]
    8. neg-sub083.4%

      \[\leadsto \left(e^{-x} - 2\right) - \color{blue}{\left(0 - e^{x}\right)} \]
    9. associate--r-83.4%

      \[\leadsto \color{blue}{\left(\left(e^{-x} - 2\right) - 0\right) + e^{x}} \]
    10. +-commutative83.4%

      \[\leadsto \color{blue}{e^{x} + \left(\left(e^{-x} - 2\right) - 0\right)} \]
    11. --rgt-identity83.4%

      \[\leadsto e^{x} + \color{blue}{\left(e^{-x} - 2\right)} \]
    12. sub-neg83.4%

      \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
    13. metadata-eval83.4%

      \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
  3. Simplified83.4%

    \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
  4. Taylor expanded in x around 0 85.2%

    \[\leadsto \color{blue}{0.08333333333333333 \cdot {x}^{4} + {x}^{2}} \]
  5. Step-by-step derivation
    1. fma-def85.2%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, {x}^{4}, {x}^{2}\right)} \]
    2. unpow285.2%

      \[\leadsto \mathsf{fma}\left(0.08333333333333333, {x}^{4}, \color{blue}{x \cdot x}\right) \]
  6. Simplified85.2%

    \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, {x}^{4}, x \cdot x\right)} \]
  7. Step-by-step derivation
    1. fma-udef85.2%

      \[\leadsto \color{blue}{0.08333333333333333 \cdot {x}^{4} + x \cdot x} \]
    2. unpow285.2%

      \[\leadsto 0.08333333333333333 \cdot {x}^{4} + \color{blue}{{x}^{2}} \]
    3. +-commutative85.2%

      \[\leadsto \color{blue}{{x}^{2} + 0.08333333333333333 \cdot {x}^{4}} \]
    4. unpow285.2%

      \[\leadsto \color{blue}{x \cdot x} + 0.08333333333333333 \cdot {x}^{4} \]
  8. Applied egg-rr85.2%

    \[\leadsto \color{blue}{x \cdot x + 0.08333333333333333 \cdot {x}^{4}} \]
  9. Step-by-step derivation
    1. metadata-eval85.2%

      \[\leadsto x \cdot x + 0.08333333333333333 \cdot {x}^{\color{blue}{\left(2 \cdot 2\right)}} \]
    2. pow-sqr85.2%

      \[\leadsto x \cdot x + 0.08333333333333333 \cdot \color{blue}{\left({x}^{2} \cdot {x}^{2}\right)} \]
    3. pow285.2%

      \[\leadsto x \cdot x + 0.08333333333333333 \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot {x}^{2}\right) \]
    4. pow285.2%

      \[\leadsto x \cdot x + 0.08333333333333333 \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{\left(x \cdot x\right)}\right) \]
    5. associate-*r*85.2%

      \[\leadsto x \cdot x + \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right)\right) \cdot \left(x \cdot x\right)} \]
    6. distribute-rgt1-in85.2%

      \[\leadsto \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right) + 1\right) \cdot \left(x \cdot x\right)} \]
    7. fma-def85.2%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, x \cdot x, 1\right)} \cdot \left(x \cdot x\right) \]
  10. Applied egg-rr85.2%

    \[\leadsto \color{blue}{\mathsf{fma}\left(0.08333333333333333, x \cdot x, 1\right) \cdot \left(x \cdot x\right)} \]
  11. Step-by-step derivation
    1. metadata-eval85.2%

      \[\leadsto \mathsf{fma}\left(0.08333333333333333, x \cdot x, \color{blue}{--1}\right) \cdot \left(x \cdot x\right) \]
    2. metadata-eval85.2%

      \[\leadsto \mathsf{fma}\left(0.08333333333333333, x \cdot x, -\color{blue}{\left(-1\right)}\right) \cdot \left(x \cdot x\right) \]
    3. fma-neg85.2%

      \[\leadsto \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right) - \left(-1\right)\right)} \cdot \left(x \cdot x\right) \]
    4. metadata-eval85.2%

      \[\leadsto \left(0.08333333333333333 \cdot \left(x \cdot x\right) - \color{blue}{-1}\right) \cdot \left(x \cdot x\right) \]
  12. Applied egg-rr85.2%

    \[\leadsto \color{blue}{\left(0.08333333333333333 \cdot \left(x \cdot x\right) - -1\right)} \cdot \left(x \cdot x\right) \]
  13. Final simplification85.2%

    \[\leadsto \left(x \cdot x\right) \cdot \left(0.08333333333333333 \cdot \left(x \cdot x\right) - -1\right) \]

Alternative 6: 75.4% accurate, 68.7× speedup?

\[\begin{array}{l} \\ x \cdot x \end{array} \]
(FPCore (x) :precision binary64 (* x x))
double code(double x) {
	return x * x;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = x * x
end function
public static double code(double x) {
	return x * x;
}
def code(x):
	return x * x
function code(x)
	return Float64(x * x)
end
function tmp = code(x)
	tmp = x * x;
end
code[x_] := N[(x * x), $MachinePrecision]
\begin{array}{l}

\\
x \cdot x
\end{array}
Derivation
  1. Initial program 83.4%

    \[\left(e^{x} - 2\right) + e^{-x} \]
  2. Step-by-step derivation
    1. +-commutative83.4%

      \[\leadsto \color{blue}{e^{-x} + \left(e^{x} - 2\right)} \]
    2. sub-neg83.4%

      \[\leadsto e^{-x} + \color{blue}{\left(e^{x} + \left(-2\right)\right)} \]
    3. +-commutative83.4%

      \[\leadsto e^{-x} + \color{blue}{\left(\left(-2\right) + e^{x}\right)} \]
    4. associate-+l+83.4%

      \[\leadsto \color{blue}{\left(e^{-x} + \left(-2\right)\right) + e^{x}} \]
    5. sub-neg83.4%

      \[\leadsto \color{blue}{\left(e^{-x} - 2\right)} + e^{x} \]
    6. remove-double-neg83.4%

      \[\leadsto \left(e^{-x} - 2\right) + \color{blue}{\left(-\left(-e^{x}\right)\right)} \]
    7. sub-neg83.4%

      \[\leadsto \color{blue}{\left(e^{-x} - 2\right) - \left(-e^{x}\right)} \]
    8. neg-sub083.4%

      \[\leadsto \left(e^{-x} - 2\right) - \color{blue}{\left(0 - e^{x}\right)} \]
    9. associate--r-83.4%

      \[\leadsto \color{blue}{\left(\left(e^{-x} - 2\right) - 0\right) + e^{x}} \]
    10. +-commutative83.4%

      \[\leadsto \color{blue}{e^{x} + \left(\left(e^{-x} - 2\right) - 0\right)} \]
    11. --rgt-identity83.4%

      \[\leadsto e^{x} + \color{blue}{\left(e^{-x} - 2\right)} \]
    12. sub-neg83.4%

      \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
    13. metadata-eval83.4%

      \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
  3. Simplified83.4%

    \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
  4. Taylor expanded in x around 0 73.3%

    \[\leadsto \color{blue}{{x}^{2}} \]
  5. Step-by-step derivation
    1. unpow273.3%

      \[\leadsto \color{blue}{x \cdot x} \]
  6. Simplified73.3%

    \[\leadsto \color{blue}{x \cdot x} \]
  7. Final simplification73.3%

    \[\leadsto x \cdot x \]

Alternative 7: 4.3% accurate, 206.0× speedup?

\[\begin{array}{l} \\ x \end{array} \]
(FPCore (x) :precision binary64 x)
double code(double x) {
	return x;
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = x
end function
public static double code(double x) {
	return x;
}
def code(x):
	return x
function code(x)
	return x
end
function tmp = code(x)
	tmp = x;
end
code[x_] := x
\begin{array}{l}

\\
x
\end{array}
Derivation
  1. Initial program 83.4%

    \[\left(e^{x} - 2\right) + e^{-x} \]
  2. Step-by-step derivation
    1. +-commutative83.4%

      \[\leadsto \color{blue}{e^{-x} + \left(e^{x} - 2\right)} \]
    2. sub-neg83.4%

      \[\leadsto e^{-x} + \color{blue}{\left(e^{x} + \left(-2\right)\right)} \]
    3. +-commutative83.4%

      \[\leadsto e^{-x} + \color{blue}{\left(\left(-2\right) + e^{x}\right)} \]
    4. associate-+l+83.4%

      \[\leadsto \color{blue}{\left(e^{-x} + \left(-2\right)\right) + e^{x}} \]
    5. sub-neg83.4%

      \[\leadsto \color{blue}{\left(e^{-x} - 2\right)} + e^{x} \]
    6. remove-double-neg83.4%

      \[\leadsto \left(e^{-x} - 2\right) + \color{blue}{\left(-\left(-e^{x}\right)\right)} \]
    7. sub-neg83.4%

      \[\leadsto \color{blue}{\left(e^{-x} - 2\right) - \left(-e^{x}\right)} \]
    8. neg-sub083.4%

      \[\leadsto \left(e^{-x} - 2\right) - \color{blue}{\left(0 - e^{x}\right)} \]
    9. associate--r-83.4%

      \[\leadsto \color{blue}{\left(\left(e^{-x} - 2\right) - 0\right) + e^{x}} \]
    10. +-commutative83.4%

      \[\leadsto \color{blue}{e^{x} + \left(\left(e^{-x} - 2\right) - 0\right)} \]
    11. --rgt-identity83.4%

      \[\leadsto e^{x} + \color{blue}{\left(e^{-x} - 2\right)} \]
    12. sub-neg83.4%

      \[\leadsto e^{x} + \color{blue}{\left(e^{-x} + \left(-2\right)\right)} \]
    13. metadata-eval83.4%

      \[\leadsto e^{x} + \left(e^{-x} + \color{blue}{-2}\right) \]
  3. Simplified83.4%

    \[\leadsto \color{blue}{e^{x} + \left(e^{-x} + -2\right)} \]
  4. Taylor expanded in x around 0 57.7%

    \[\leadsto e^{x} + \color{blue}{-1} \]
  5. Taylor expanded in x around 0 4.5%

    \[\leadsto \color{blue}{x} \]
  6. Final simplification4.5%

    \[\leadsto x \]

Developer target: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ 4 \cdot {\sinh \left(\frac{x}{2}\right)}^{2} \end{array} \]
(FPCore (x) :precision binary64 (* 4.0 (pow (sinh (/ x 2.0)) 2.0)))
double code(double x) {
	return 4.0 * pow(sinh((x / 2.0)), 2.0);
}
real(8) function code(x)
    real(8), intent (in) :: x
    code = 4.0d0 * (sinh((x / 2.0d0)) ** 2.0d0)
end function
public static double code(double x) {
	return 4.0 * Math.pow(Math.sinh((x / 2.0)), 2.0);
}
def code(x):
	return 4.0 * math.pow(math.sinh((x / 2.0)), 2.0)
function code(x)
	return Float64(4.0 * (sinh(Float64(x / 2.0)) ^ 2.0))
end
function tmp = code(x)
	tmp = 4.0 * (sinh((x / 2.0)) ^ 2.0);
end
code[x_] := N[(4.0 * N[Power[N[Sinh[N[(x / 2.0), $MachinePrecision]], $MachinePrecision], 2.0], $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
4 \cdot {\sinh \left(\frac{x}{2}\right)}^{2}
\end{array}

Reproduce

?
herbie shell --seed 2023297 
(FPCore (x)
  :name "exp2 (problem 3.3.7)"
  :precision binary64

  :herbie-target
  (* 4.0 (pow (sinh (/ x 2.0)) 2.0))

  (+ (- (exp x) 2.0) (exp (- x))))