expax (section 3.5)

Percentage Accurate: 65.7% → 100.0%
Time: 6.0s
Alternatives: 8
Speedup: 7.0×

Specification

?
\[\begin{array}{l} \\ e^{a \cdot x} - 1 \end{array} \]
(FPCore (a x) :precision binary64 (- (exp (* a x)) 1.0))
double code(double a, double x) {
	return exp((a * x)) - 1.0;
}
real(8) function code(a, x)
    real(8), intent (in) :: a
    real(8), intent (in) :: x
    code = exp((a * x)) - 1.0d0
end function
public static double code(double a, double x) {
	return Math.exp((a * x)) - 1.0;
}
def code(a, x):
	return math.exp((a * x)) - 1.0
function code(a, x)
	return Float64(exp(Float64(a * x)) - 1.0)
end
function tmp = code(a, x)
	tmp = exp((a * x)) - 1.0;
end
code[a_, x_] := N[(N[Exp[N[(a * x), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision]
\begin{array}{l}

\\
e^{a \cdot x} - 1
\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 8 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: 65.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ e^{a \cdot x} - 1 \end{array} \]
(FPCore (a x) :precision binary64 (- (exp (* a x)) 1.0))
double code(double a, double x) {
	return exp((a * x)) - 1.0;
}
real(8) function code(a, x)
    real(8), intent (in) :: a
    real(8), intent (in) :: x
    code = exp((a * x)) - 1.0d0
end function
public static double code(double a, double x) {
	return Math.exp((a * x)) - 1.0;
}
def code(a, x):
	return math.exp((a * x)) - 1.0
function code(a, x)
	return Float64(exp(Float64(a * x)) - 1.0)
end
function tmp = code(a, x)
	tmp = exp((a * x)) - 1.0;
end
code[a_, x_] := N[(N[Exp[N[(a * x), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision]
\begin{array}{l}

\\
e^{a \cdot x} - 1
\end{array}

Alternative 1: 100.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \mathsf{expm1}\left(a \cdot x\right) \end{array} \]
(FPCore (a x) :precision binary64 (expm1 (* a x)))
double code(double a, double x) {
	return expm1((a * x));
}
public static double code(double a, double x) {
	return Math.expm1((a * x));
}
def code(a, x):
	return math.expm1((a * x))
function code(a, x)
	return expm1(Float64(a * x))
end
code[a_, x_] := N[(Exp[N[(a * x), $MachinePrecision]] - 1), $MachinePrecision]
\begin{array}{l}

\\
\mathsf{expm1}\left(a \cdot x\right)
\end{array}
Derivation
  1. Initial program 64.0%

    \[e^{a \cdot x} - 1 \]
  2. Step-by-step derivation
    1. expm1-def99.9%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
  3. Simplified99.9%

    \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
  4. Final simplification99.9%

    \[\leadsto \mathsf{expm1}\left(a \cdot x\right) \]

Alternative 2: 70.3% accurate, 6.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot x \leq -4000000000000:\\ \;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\ \mathbf{elif}\;a \cdot x \leq 10^{+91}:\\ \;\;\;\;a \cdot x\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \left(\left(a \cdot a\right) \cdot \left(x \cdot x\right)\right)\\ \end{array} \end{array} \]
(FPCore (a x)
 :precision binary64
 (if (<= (* a x) -4000000000000.0)
   (- -2.0 (/ (/ 4.0 a) x))
   (if (<= (* a x) 1e+91) (* a x) (* 0.5 (* (* a a) (* x x))))))
double code(double a, double x) {
	double tmp;
	if ((a * x) <= -4000000000000.0) {
		tmp = -2.0 - ((4.0 / a) / x);
	} else if ((a * x) <= 1e+91) {
		tmp = a * x;
	} else {
		tmp = 0.5 * ((a * a) * (x * x));
	}
	return tmp;
}
real(8) function code(a, x)
    real(8), intent (in) :: a
    real(8), intent (in) :: x
    real(8) :: tmp
    if ((a * x) <= (-4000000000000.0d0)) then
        tmp = (-2.0d0) - ((4.0d0 / a) / x)
    else if ((a * x) <= 1d+91) then
        tmp = a * x
    else
        tmp = 0.5d0 * ((a * a) * (x * x))
    end if
    code = tmp
end function
public static double code(double a, double x) {
	double tmp;
	if ((a * x) <= -4000000000000.0) {
		tmp = -2.0 - ((4.0 / a) / x);
	} else if ((a * x) <= 1e+91) {
		tmp = a * x;
	} else {
		tmp = 0.5 * ((a * a) * (x * x));
	}
	return tmp;
}
def code(a, x):
	tmp = 0
	if (a * x) <= -4000000000000.0:
		tmp = -2.0 - ((4.0 / a) / x)
	elif (a * x) <= 1e+91:
		tmp = a * x
	else:
		tmp = 0.5 * ((a * a) * (x * x))
	return tmp
function code(a, x)
	tmp = 0.0
	if (Float64(a * x) <= -4000000000000.0)
		tmp = Float64(-2.0 - Float64(Float64(4.0 / a) / x));
	elseif (Float64(a * x) <= 1e+91)
		tmp = Float64(a * x);
	else
		tmp = Float64(0.5 * Float64(Float64(a * a) * Float64(x * x)));
	end
	return tmp
end
function tmp_2 = code(a, x)
	tmp = 0.0;
	if ((a * x) <= -4000000000000.0)
		tmp = -2.0 - ((4.0 / a) / x);
	elseif ((a * x) <= 1e+91)
		tmp = a * x;
	else
		tmp = 0.5 * ((a * a) * (x * x));
	end
	tmp_2 = tmp;
end
code[a_, x_] := If[LessEqual[N[(a * x), $MachinePrecision], -4000000000000.0], N[(-2.0 - N[(N[(4.0 / a), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision], If[LessEqual[N[(a * x), $MachinePrecision], 1e+91], N[(a * x), $MachinePrecision], N[(0.5 * N[(N[(a * a), $MachinePrecision] * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \cdot x \leq -4000000000000:\\
\;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\

\mathbf{elif}\;a \cdot x \leq 10^{+91}:\\
\;\;\;\;a \cdot x\\

\mathbf{else}:\\
\;\;\;\;0.5 \cdot \left(\left(a \cdot a\right) \cdot \left(x \cdot x\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 a x) < -4e12

    1. Initial program 100.0%

      \[e^{a \cdot x} - 1 \]
    2. Step-by-step derivation
      1. expm1-def100.0%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    4. Taylor expanded in a around 0 0.5%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative0.5%

        \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
      2. associate-*r*0.5%

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow20.5%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*0.9%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out1.1%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative1.1%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative1.1%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow21.1%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*1.1%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified1.1%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. distribute-lft-in0.9%

        \[\leadsto \color{blue}{x \cdot a + x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      2. flip-+0.6%

        \[\leadsto \color{blue}{\frac{\left(x \cdot a\right) \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)}} \]
      3. *-commutative0.6%

        \[\leadsto \frac{\color{blue}{\left(a \cdot x\right)} \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      4. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \color{blue}{\left(a \cdot x\right)} - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      5. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      6. associate-*l*0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      7. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      8. associate-*l*0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      9. *-commutative0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{a \cdot x} - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      10. *-commutative0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}} \]
      11. associate-*l*0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
    8. Applied egg-rr0.4%

      \[\leadsto \color{blue}{\frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
    9. Taylor expanded in a around 0 5.0%

      \[\leadsto \frac{\color{blue}{{a}^{2} \cdot {x}^{2}}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    10. Step-by-step derivation
      1. unpow25.0%

        \[\leadsto \frac{\color{blue}{\left(a \cdot a\right)} \cdot {x}^{2}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
      2. unpow25.0%

        \[\leadsto \frac{\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    11. Simplified5.0%

      \[\leadsto \frac{\color{blue}{\left(a \cdot a\right) \cdot \left(x \cdot x\right)}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    12. Taylor expanded in a around inf 18.8%

      \[\leadsto \color{blue}{-\left(2 + 4 \cdot \frac{1}{a \cdot x}\right)} \]
    13. Step-by-step derivation
      1. distribute-neg-in18.8%

        \[\leadsto \color{blue}{\left(-2\right) + \left(-4 \cdot \frac{1}{a \cdot x}\right)} \]
      2. unsub-neg18.8%

        \[\leadsto \color{blue}{\left(-2\right) - 4 \cdot \frac{1}{a \cdot x}} \]
      3. metadata-eval18.8%

        \[\leadsto \color{blue}{-2} - 4 \cdot \frac{1}{a \cdot x} \]
      4. associate-*r/18.8%

        \[\leadsto -2 - \color{blue}{\frac{4 \cdot 1}{a \cdot x}} \]
      5. metadata-eval18.8%

        \[\leadsto -2 - \frac{\color{blue}{4}}{a \cdot x} \]
      6. associate-/r*18.8%

        \[\leadsto -2 - \color{blue}{\frac{\frac{4}{a}}{x}} \]
    14. Simplified18.8%

      \[\leadsto \color{blue}{-2 - \frac{\frac{4}{a}}{x}} \]

    if -4e12 < (*.f64 a x) < 1.00000000000000008e91

    1. Initial program 38.1%

      \[e^{a \cdot x} - 1 \]
    2. Step-by-step derivation
      1. expm1-def99.9%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    4. Taylor expanded in a around 0 84.6%

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

    if 1.00000000000000008e91 < (*.f64 a x)

    1. Initial program 100.0%

      \[e^{a \cdot x} - 1 \]
    2. Step-by-step derivation
      1. expm1-def100.0%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    4. Taylor expanded in a around 0 96.3%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. *-commutative96.3%

        \[\leadsto \color{blue}{\left({a}^{2} \cdot {x}^{2}\right) \cdot 0.5} + a \cdot x \]
      2. associate-*l*96.3%

        \[\leadsto \color{blue}{{a}^{2} \cdot \left({x}^{2} \cdot 0.5\right)} + a \cdot x \]
      3. unpow296.3%

        \[\leadsto \color{blue}{\left(a \cdot a\right)} \cdot \left({x}^{2} \cdot 0.5\right) + a \cdot x \]
      4. associate-*l*86.6%

        \[\leadsto \color{blue}{a \cdot \left(a \cdot \left({x}^{2} \cdot 0.5\right)\right)} + a \cdot x \]
      5. distribute-lft-out86.6%

        \[\leadsto \color{blue}{a \cdot \left(a \cdot \left({x}^{2} \cdot 0.5\right) + x\right)} \]
      6. unpow286.6%

        \[\leadsto a \cdot \left(a \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot 0.5\right) + x\right) \]
      7. associate-*l*86.6%

        \[\leadsto a \cdot \left(a \cdot \color{blue}{\left(x \cdot \left(x \cdot 0.5\right)\right)} + x\right) \]
    6. Simplified86.6%

      \[\leadsto \color{blue}{a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right) + x\right)} \]
    7. Taylor expanded in a around inf 96.3%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
    8. Step-by-step derivation
      1. *-commutative96.3%

        \[\leadsto \color{blue}{\left({a}^{2} \cdot {x}^{2}\right) \cdot 0.5} \]
      2. unpow296.3%

        \[\leadsto \left(\color{blue}{\left(a \cdot a\right)} \cdot {x}^{2}\right) \cdot 0.5 \]
      3. unpow296.3%

        \[\leadsto \left(\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot 0.5 \]
      4. associate-*r*96.3%

        \[\leadsto \color{blue}{\left(a \cdot a\right) \cdot \left(\left(x \cdot x\right) \cdot 0.5\right)} \]
      5. rem-square-sqrt96.3%

        \[\leadsto \left(a \cdot a\right) \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{\left(\sqrt{0.5} \cdot \sqrt{0.5}\right)}\right) \]
      6. swap-sqr96.3%

        \[\leadsto \left(a \cdot a\right) \cdot \color{blue}{\left(\left(x \cdot \sqrt{0.5}\right) \cdot \left(x \cdot \sqrt{0.5}\right)\right)} \]
      7. swap-sqr78.9%

        \[\leadsto \color{blue}{\left(a \cdot \left(x \cdot \sqrt{0.5}\right)\right) \cdot \left(a \cdot \left(x \cdot \sqrt{0.5}\right)\right)} \]
      8. rem-square-sqrt36.4%

        \[\leadsto \left(a \cdot \left(x \cdot \sqrt{0.5}\right)\right) \cdot \left(\color{blue}{\left(\sqrt{a} \cdot \sqrt{a}\right)} \cdot \left(x \cdot \sqrt{0.5}\right)\right) \]
      9. associate-*r*36.4%

        \[\leadsto \left(a \cdot \left(x \cdot \sqrt{0.5}\right)\right) \cdot \color{blue}{\left(\sqrt{a} \cdot \left(\sqrt{a} \cdot \left(x \cdot \sqrt{0.5}\right)\right)\right)} \]
      10. *-commutative36.4%

        \[\leadsto \left(a \cdot \left(x \cdot \sqrt{0.5}\right)\right) \cdot \color{blue}{\left(\left(\sqrt{a} \cdot \left(x \cdot \sqrt{0.5}\right)\right) \cdot \sqrt{a}\right)} \]
      11. associate-*l*40.2%

        \[\leadsto \color{blue}{a \cdot \left(\left(x \cdot \sqrt{0.5}\right) \cdot \left(\left(\sqrt{a} \cdot \left(x \cdot \sqrt{0.5}\right)\right) \cdot \sqrt{a}\right)\right)} \]
      12. *-commutative40.2%

        \[\leadsto a \cdot \left(\left(x \cdot \sqrt{0.5}\right) \cdot \color{blue}{\left(\sqrt{a} \cdot \left(\sqrt{a} \cdot \left(x \cdot \sqrt{0.5}\right)\right)\right)}\right) \]
      13. associate-*l*40.2%

        \[\leadsto a \cdot \color{blue}{\left(\left(\left(x \cdot \sqrt{0.5}\right) \cdot \sqrt{a}\right) \cdot \left(\sqrt{a} \cdot \left(x \cdot \sqrt{0.5}\right)\right)\right)} \]
      14. *-commutative40.2%

        \[\leadsto a \cdot \left(\color{blue}{\left(\sqrt{a} \cdot \left(x \cdot \sqrt{0.5}\right)\right)} \cdot \left(\sqrt{a} \cdot \left(x \cdot \sqrt{0.5}\right)\right)\right) \]
      15. swap-sqr40.2%

        \[\leadsto a \cdot \color{blue}{\left(\left(\sqrt{a} \cdot \sqrt{a}\right) \cdot \left(\left(x \cdot \sqrt{0.5}\right) \cdot \left(x \cdot \sqrt{0.5}\right)\right)\right)} \]
      16. rem-square-sqrt86.6%

        \[\leadsto a \cdot \left(\color{blue}{a} \cdot \left(\left(x \cdot \sqrt{0.5}\right) \cdot \left(x \cdot \sqrt{0.5}\right)\right)\right) \]
      17. swap-sqr86.6%

        \[\leadsto a \cdot \left(a \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot \left(\sqrt{0.5} \cdot \sqrt{0.5}\right)\right)}\right) \]
    9. Simplified86.6%

      \[\leadsto \color{blue}{a \cdot \left(a \cdot \left(x \cdot \left(0.5 \cdot x\right)\right)\right)} \]
    10. Taylor expanded in a around 0 96.3%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
    11. Step-by-step derivation
      1. unpow296.3%

        \[\leadsto 0.5 \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot {x}^{2}\right) \]
      2. unpow296.3%

        \[\leadsto 0.5 \cdot \left(\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}\right) \]
    12. Simplified96.3%

      \[\leadsto \color{blue}{0.5 \cdot \left(\left(a \cdot a\right) \cdot \left(x \cdot x\right)\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification71.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \cdot x \leq -4000000000000:\\ \;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\ \mathbf{elif}\;a \cdot x \leq 10^{+91}:\\ \;\;\;\;a \cdot x\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \left(\left(a \cdot a\right) \cdot \left(x \cdot x\right)\right)\\ \end{array} \]

Alternative 3: 70.7% accurate, 6.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot x \leq -4000000000000:\\ \;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\ \mathbf{elif}\;a \cdot x \leq 500000:\\ \;\;\;\;a \cdot x\\ \mathbf{else}:\\ \;\;\;\;a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right)\right)\\ \end{array} \end{array} \]
(FPCore (a x)
 :precision binary64
 (if (<= (* a x) -4000000000000.0)
   (- -2.0 (/ (/ 4.0 a) x))
   (if (<= (* a x) 500000.0) (* a x) (* a (* a (* x (* x 0.5)))))))
double code(double a, double x) {
	double tmp;
	if ((a * x) <= -4000000000000.0) {
		tmp = -2.0 - ((4.0 / a) / x);
	} else if ((a * x) <= 500000.0) {
		tmp = a * x;
	} else {
		tmp = a * (a * (x * (x * 0.5)));
	}
	return tmp;
}
real(8) function code(a, x)
    real(8), intent (in) :: a
    real(8), intent (in) :: x
    real(8) :: tmp
    if ((a * x) <= (-4000000000000.0d0)) then
        tmp = (-2.0d0) - ((4.0d0 / a) / x)
    else if ((a * x) <= 500000.0d0) then
        tmp = a * x
    else
        tmp = a * (a * (x * (x * 0.5d0)))
    end if
    code = tmp
end function
public static double code(double a, double x) {
	double tmp;
	if ((a * x) <= -4000000000000.0) {
		tmp = -2.0 - ((4.0 / a) / x);
	} else if ((a * x) <= 500000.0) {
		tmp = a * x;
	} else {
		tmp = a * (a * (x * (x * 0.5)));
	}
	return tmp;
}
def code(a, x):
	tmp = 0
	if (a * x) <= -4000000000000.0:
		tmp = -2.0 - ((4.0 / a) / x)
	elif (a * x) <= 500000.0:
		tmp = a * x
	else:
		tmp = a * (a * (x * (x * 0.5)))
	return tmp
function code(a, x)
	tmp = 0.0
	if (Float64(a * x) <= -4000000000000.0)
		tmp = Float64(-2.0 - Float64(Float64(4.0 / a) / x));
	elseif (Float64(a * x) <= 500000.0)
		tmp = Float64(a * x);
	else
		tmp = Float64(a * Float64(a * Float64(x * Float64(x * 0.5))));
	end
	return tmp
end
function tmp_2 = code(a, x)
	tmp = 0.0;
	if ((a * x) <= -4000000000000.0)
		tmp = -2.0 - ((4.0 / a) / x);
	elseif ((a * x) <= 500000.0)
		tmp = a * x;
	else
		tmp = a * (a * (x * (x * 0.5)));
	end
	tmp_2 = tmp;
end
code[a_, x_] := If[LessEqual[N[(a * x), $MachinePrecision], -4000000000000.0], N[(-2.0 - N[(N[(4.0 / a), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision], If[LessEqual[N[(a * x), $MachinePrecision], 500000.0], N[(a * x), $MachinePrecision], N[(a * N[(a * N[(x * N[(x * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \cdot x \leq -4000000000000:\\
\;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\

\mathbf{elif}\;a \cdot x \leq 500000:\\
\;\;\;\;a \cdot x\\

\mathbf{else}:\\
\;\;\;\;a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 a x) < -4e12

    1. Initial program 100.0%

      \[e^{a \cdot x} - 1 \]
    2. Step-by-step derivation
      1. expm1-def100.0%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    4. Taylor expanded in a around 0 0.5%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative0.5%

        \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
      2. associate-*r*0.5%

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow20.5%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*0.9%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out1.1%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative1.1%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative1.1%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow21.1%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*1.1%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified1.1%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. distribute-lft-in0.9%

        \[\leadsto \color{blue}{x \cdot a + x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      2. flip-+0.6%

        \[\leadsto \color{blue}{\frac{\left(x \cdot a\right) \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)}} \]
      3. *-commutative0.6%

        \[\leadsto \frac{\color{blue}{\left(a \cdot x\right)} \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      4. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \color{blue}{\left(a \cdot x\right)} - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      5. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      6. associate-*l*0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      7. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      8. associate-*l*0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      9. *-commutative0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{a \cdot x} - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      10. *-commutative0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}} \]
      11. associate-*l*0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
    8. Applied egg-rr0.4%

      \[\leadsto \color{blue}{\frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
    9. Taylor expanded in a around 0 5.0%

      \[\leadsto \frac{\color{blue}{{a}^{2} \cdot {x}^{2}}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    10. Step-by-step derivation
      1. unpow25.0%

        \[\leadsto \frac{\color{blue}{\left(a \cdot a\right)} \cdot {x}^{2}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
      2. unpow25.0%

        \[\leadsto \frac{\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    11. Simplified5.0%

      \[\leadsto \frac{\color{blue}{\left(a \cdot a\right) \cdot \left(x \cdot x\right)}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    12. Taylor expanded in a around inf 18.8%

      \[\leadsto \color{blue}{-\left(2 + 4 \cdot \frac{1}{a \cdot x}\right)} \]
    13. Step-by-step derivation
      1. distribute-neg-in18.8%

        \[\leadsto \color{blue}{\left(-2\right) + \left(-4 \cdot \frac{1}{a \cdot x}\right)} \]
      2. unsub-neg18.8%

        \[\leadsto \color{blue}{\left(-2\right) - 4 \cdot \frac{1}{a \cdot x}} \]
      3. metadata-eval18.8%

        \[\leadsto \color{blue}{-2} - 4 \cdot \frac{1}{a \cdot x} \]
      4. associate-*r/18.8%

        \[\leadsto -2 - \color{blue}{\frac{4 \cdot 1}{a \cdot x}} \]
      5. metadata-eval18.8%

        \[\leadsto -2 - \frac{\color{blue}{4}}{a \cdot x} \]
      6. associate-/r*18.8%

        \[\leadsto -2 - \color{blue}{\frac{\frac{4}{a}}{x}} \]
    14. Simplified18.8%

      \[\leadsto \color{blue}{-2 - \frac{\frac{4}{a}}{x}} \]

    if -4e12 < (*.f64 a x) < 5e5

    1. Initial program 30.2%

      \[e^{a \cdot x} - 1 \]
    2. Step-by-step derivation
      1. expm1-def99.9%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    4. Taylor expanded in a around 0 95.0%

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

    if 5e5 < (*.f64 a x)

    1. Initial program 100.0%

      \[e^{a \cdot x} - 1 \]
    2. Step-by-step derivation
      1. expm1-def100.0%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    4. Taylor expanded in a around 0 71.6%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. *-commutative71.6%

        \[\leadsto \color{blue}{\left({a}^{2} \cdot {x}^{2}\right) \cdot 0.5} + a \cdot x \]
      2. associate-*l*71.6%

        \[\leadsto \color{blue}{{a}^{2} \cdot \left({x}^{2} \cdot 0.5\right)} + a \cdot x \]
      3. unpow271.6%

        \[\leadsto \color{blue}{\left(a \cdot a\right)} \cdot \left({x}^{2} \cdot 0.5\right) + a \cdot x \]
      4. associate-*l*70.9%

        \[\leadsto \color{blue}{a \cdot \left(a \cdot \left({x}^{2} \cdot 0.5\right)\right)} + a \cdot x \]
      5. distribute-lft-out70.9%

        \[\leadsto \color{blue}{a \cdot \left(a \cdot \left({x}^{2} \cdot 0.5\right) + x\right)} \]
      6. unpow270.9%

        \[\leadsto a \cdot \left(a \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot 0.5\right) + x\right) \]
      7. associate-*l*70.9%

        \[\leadsto a \cdot \left(a \cdot \color{blue}{\left(x \cdot \left(x \cdot 0.5\right)\right)} + x\right) \]
    6. Simplified70.9%

      \[\leadsto \color{blue}{a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right) + x\right)} \]
    7. Taylor expanded in a around inf 71.6%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
    8. Step-by-step derivation
      1. *-commutative71.6%

        \[\leadsto \color{blue}{\left({a}^{2} \cdot {x}^{2}\right) \cdot 0.5} \]
      2. unpow271.6%

        \[\leadsto \left(\color{blue}{\left(a \cdot a\right)} \cdot {x}^{2}\right) \cdot 0.5 \]
      3. unpow271.6%

        \[\leadsto \left(\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot 0.5 \]
      4. associate-*r*71.6%

        \[\leadsto \color{blue}{\left(a \cdot a\right) \cdot \left(\left(x \cdot x\right) \cdot 0.5\right)} \]
      5. rem-square-sqrt71.6%

        \[\leadsto \left(a \cdot a\right) \cdot \left(\left(x \cdot x\right) \cdot \color{blue}{\left(\sqrt{0.5} \cdot \sqrt{0.5}\right)}\right) \]
      6. swap-sqr71.6%

        \[\leadsto \left(a \cdot a\right) \cdot \color{blue}{\left(\left(x \cdot \sqrt{0.5}\right) \cdot \left(x \cdot \sqrt{0.5}\right)\right)} \]
      7. swap-sqr59.3%

        \[\leadsto \color{blue}{\left(a \cdot \left(x \cdot \sqrt{0.5}\right)\right) \cdot \left(a \cdot \left(x \cdot \sqrt{0.5}\right)\right)} \]
      8. rem-square-sqrt27.5%

        \[\leadsto \left(a \cdot \left(x \cdot \sqrt{0.5}\right)\right) \cdot \left(\color{blue}{\left(\sqrt{a} \cdot \sqrt{a}\right)} \cdot \left(x \cdot \sqrt{0.5}\right)\right) \]
      9. associate-*r*27.5%

        \[\leadsto \left(a \cdot \left(x \cdot \sqrt{0.5}\right)\right) \cdot \color{blue}{\left(\sqrt{a} \cdot \left(\sqrt{a} \cdot \left(x \cdot \sqrt{0.5}\right)\right)\right)} \]
      10. *-commutative27.5%

        \[\leadsto \left(a \cdot \left(x \cdot \sqrt{0.5}\right)\right) \cdot \color{blue}{\left(\left(\sqrt{a} \cdot \left(x \cdot \sqrt{0.5}\right)\right) \cdot \sqrt{a}\right)} \]
      11. associate-*l*31.8%

        \[\leadsto \color{blue}{a \cdot \left(\left(x \cdot \sqrt{0.5}\right) \cdot \left(\left(\sqrt{a} \cdot \left(x \cdot \sqrt{0.5}\right)\right) \cdot \sqrt{a}\right)\right)} \]
      12. *-commutative31.8%

        \[\leadsto a \cdot \left(\left(x \cdot \sqrt{0.5}\right) \cdot \color{blue}{\left(\sqrt{a} \cdot \left(\sqrt{a} \cdot \left(x \cdot \sqrt{0.5}\right)\right)\right)}\right) \]
      13. associate-*l*31.8%

        \[\leadsto a \cdot \color{blue}{\left(\left(\left(x \cdot \sqrt{0.5}\right) \cdot \sqrt{a}\right) \cdot \left(\sqrt{a} \cdot \left(x \cdot \sqrt{0.5}\right)\right)\right)} \]
      14. *-commutative31.8%

        \[\leadsto a \cdot \left(\color{blue}{\left(\sqrt{a} \cdot \left(x \cdot \sqrt{0.5}\right)\right)} \cdot \left(\sqrt{a} \cdot \left(x \cdot \sqrt{0.5}\right)\right)\right) \]
      15. swap-sqr36.1%

        \[\leadsto a \cdot \color{blue}{\left(\left(\sqrt{a} \cdot \sqrt{a}\right) \cdot \left(\left(x \cdot \sqrt{0.5}\right) \cdot \left(x \cdot \sqrt{0.5}\right)\right)\right)} \]
      16. rem-square-sqrt70.8%

        \[\leadsto a \cdot \left(\color{blue}{a} \cdot \left(\left(x \cdot \sqrt{0.5}\right) \cdot \left(x \cdot \sqrt{0.5}\right)\right)\right) \]
      17. swap-sqr70.8%

        \[\leadsto a \cdot \left(a \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot \left(\sqrt{0.5} \cdot \sqrt{0.5}\right)\right)}\right) \]
    9. Simplified70.8%

      \[\leadsto \color{blue}{a \cdot \left(a \cdot \left(x \cdot \left(0.5 \cdot x\right)\right)\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification71.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \cdot x \leq -4000000000000:\\ \;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\ \mathbf{elif}\;a \cdot x \leq 500000:\\ \;\;\;\;a \cdot x\\ \mathbf{else}:\\ \;\;\;\;a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right)\right)\\ \end{array} \]

Alternative 4: 70.0% accurate, 6.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot x \leq -4000000000000:\\ \;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\ \mathbf{else}:\\ \;\;\;\;a \cdot x + a \cdot \left(x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)\\ \end{array} \end{array} \]
(FPCore (a x)
 :precision binary64
 (if (<= (* a x) -4000000000000.0)
   (- -2.0 (/ (/ 4.0 a) x))
   (+ (* a x) (* a (* x (* a (* x 0.5)))))))
double code(double a, double x) {
	double tmp;
	if ((a * x) <= -4000000000000.0) {
		tmp = -2.0 - ((4.0 / a) / x);
	} else {
		tmp = (a * x) + (a * (x * (a * (x * 0.5))));
	}
	return tmp;
}
real(8) function code(a, x)
    real(8), intent (in) :: a
    real(8), intent (in) :: x
    real(8) :: tmp
    if ((a * x) <= (-4000000000000.0d0)) then
        tmp = (-2.0d0) - ((4.0d0 / a) / x)
    else
        tmp = (a * x) + (a * (x * (a * (x * 0.5d0))))
    end if
    code = tmp
end function
public static double code(double a, double x) {
	double tmp;
	if ((a * x) <= -4000000000000.0) {
		tmp = -2.0 - ((4.0 / a) / x);
	} else {
		tmp = (a * x) + (a * (x * (a * (x * 0.5))));
	}
	return tmp;
}
def code(a, x):
	tmp = 0
	if (a * x) <= -4000000000000.0:
		tmp = -2.0 - ((4.0 / a) / x)
	else:
		tmp = (a * x) + (a * (x * (a * (x * 0.5))))
	return tmp
function code(a, x)
	tmp = 0.0
	if (Float64(a * x) <= -4000000000000.0)
		tmp = Float64(-2.0 - Float64(Float64(4.0 / a) / x));
	else
		tmp = Float64(Float64(a * x) + Float64(a * Float64(x * Float64(a * Float64(x * 0.5)))));
	end
	return tmp
end
function tmp_2 = code(a, x)
	tmp = 0.0;
	if ((a * x) <= -4000000000000.0)
		tmp = -2.0 - ((4.0 / a) / x);
	else
		tmp = (a * x) + (a * (x * (a * (x * 0.5))));
	end
	tmp_2 = tmp;
end
code[a_, x_] := If[LessEqual[N[(a * x), $MachinePrecision], -4000000000000.0], N[(-2.0 - N[(N[(4.0 / a), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision], N[(N[(a * x), $MachinePrecision] + N[(a * N[(x * N[(a * N[(x * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \cdot x \leq -4000000000000:\\
\;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\

\mathbf{else}:\\
\;\;\;\;a \cdot x + a \cdot \left(x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 a x) < -4e12

    1. Initial program 100.0%

      \[e^{a \cdot x} - 1 \]
    2. Step-by-step derivation
      1. expm1-def100.0%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    4. Taylor expanded in a around 0 0.5%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative0.5%

        \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
      2. associate-*r*0.5%

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow20.5%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*0.9%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out1.1%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative1.1%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative1.1%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow21.1%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*1.1%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified1.1%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. distribute-lft-in0.9%

        \[\leadsto \color{blue}{x \cdot a + x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      2. flip-+0.6%

        \[\leadsto \color{blue}{\frac{\left(x \cdot a\right) \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)}} \]
      3. *-commutative0.6%

        \[\leadsto \frac{\color{blue}{\left(a \cdot x\right)} \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      4. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \color{blue}{\left(a \cdot x\right)} - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      5. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      6. associate-*l*0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      7. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      8. associate-*l*0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      9. *-commutative0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{a \cdot x} - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      10. *-commutative0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}} \]
      11. associate-*l*0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
    8. Applied egg-rr0.4%

      \[\leadsto \color{blue}{\frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
    9. Taylor expanded in a around 0 5.0%

      \[\leadsto \frac{\color{blue}{{a}^{2} \cdot {x}^{2}}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    10. Step-by-step derivation
      1. unpow25.0%

        \[\leadsto \frac{\color{blue}{\left(a \cdot a\right)} \cdot {x}^{2}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
      2. unpow25.0%

        \[\leadsto \frac{\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    11. Simplified5.0%

      \[\leadsto \frac{\color{blue}{\left(a \cdot a\right) \cdot \left(x \cdot x\right)}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    12. Taylor expanded in a around inf 18.8%

      \[\leadsto \color{blue}{-\left(2 + 4 \cdot \frac{1}{a \cdot x}\right)} \]
    13. Step-by-step derivation
      1. distribute-neg-in18.8%

        \[\leadsto \color{blue}{\left(-2\right) + \left(-4 \cdot \frac{1}{a \cdot x}\right)} \]
      2. unsub-neg18.8%

        \[\leadsto \color{blue}{\left(-2\right) - 4 \cdot \frac{1}{a \cdot x}} \]
      3. metadata-eval18.8%

        \[\leadsto \color{blue}{-2} - 4 \cdot \frac{1}{a \cdot x} \]
      4. associate-*r/18.8%

        \[\leadsto -2 - \color{blue}{\frac{4 \cdot 1}{a \cdot x}} \]
      5. metadata-eval18.8%

        \[\leadsto -2 - \frac{\color{blue}{4}}{a \cdot x} \]
      6. associate-/r*18.8%

        \[\leadsto -2 - \color{blue}{\frac{\frac{4}{a}}{x}} \]
    14. Simplified18.8%

      \[\leadsto \color{blue}{-2 - \frac{\frac{4}{a}}{x}} \]

    if -4e12 < (*.f64 a x)

    1. Initial program 53.2%

      \[e^{a \cdot x} - 1 \]
    2. Step-by-step derivation
      1. expm1-def99.9%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    4. Taylor expanded in a around 0 80.1%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. *-commutative80.1%

        \[\leadsto \color{blue}{\left({a}^{2} \cdot {x}^{2}\right) \cdot 0.5} + a \cdot x \]
      2. associate-*l*80.1%

        \[\leadsto \color{blue}{{a}^{2} \cdot \left({x}^{2} \cdot 0.5\right)} + a \cdot x \]
      3. unpow280.1%

        \[\leadsto \color{blue}{\left(a \cdot a\right)} \cdot \left({x}^{2} \cdot 0.5\right) + a \cdot x \]
      4. associate-*l*86.3%

        \[\leadsto \color{blue}{a \cdot \left(a \cdot \left({x}^{2} \cdot 0.5\right)\right)} + a \cdot x \]
      5. distribute-lft-out86.3%

        \[\leadsto \color{blue}{a \cdot \left(a \cdot \left({x}^{2} \cdot 0.5\right) + x\right)} \]
      6. unpow286.3%

        \[\leadsto a \cdot \left(a \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot 0.5\right) + x\right) \]
      7. associate-*l*86.3%

        \[\leadsto a \cdot \left(a \cdot \color{blue}{\left(x \cdot \left(x \cdot 0.5\right)\right)} + x\right) \]
    6. Simplified86.3%

      \[\leadsto \color{blue}{a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right) + x\right)} \]
    7. Step-by-step derivation
      1. distribute-lft-in86.3%

        \[\leadsto \color{blue}{a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right)\right) + a \cdot x} \]
      2. *-commutative86.3%

        \[\leadsto a \cdot \color{blue}{\left(\left(x \cdot \left(x \cdot 0.5\right)\right) \cdot a\right)} + a \cdot x \]
      3. associate-*l*86.1%

        \[\leadsto a \cdot \color{blue}{\left(x \cdot \left(\left(x \cdot 0.5\right) \cdot a\right)\right)} + a \cdot x \]
    8. Applied egg-rr86.1%

      \[\leadsto \color{blue}{a \cdot \left(x \cdot \left(\left(x \cdot 0.5\right) \cdot a\right)\right) + a \cdot x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification70.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \cdot x \leq -4000000000000:\\ \;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\ \mathbf{else}:\\ \;\;\;\;a \cdot x + a \cdot \left(x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)\\ \end{array} \]

Alternative 5: 70.0% accurate, 7.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot x \leq -4000000000000:\\ \;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\ \mathbf{else}:\\ \;\;\;\;a \cdot \left(x + x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)\\ \end{array} \end{array} \]
(FPCore (a x)
 :precision binary64
 (if (<= (* a x) -4000000000000.0)
   (- -2.0 (/ (/ 4.0 a) x))
   (* a (+ x (* x (* a (* x 0.5)))))))
double code(double a, double x) {
	double tmp;
	if ((a * x) <= -4000000000000.0) {
		tmp = -2.0 - ((4.0 / a) / x);
	} else {
		tmp = a * (x + (x * (a * (x * 0.5))));
	}
	return tmp;
}
real(8) function code(a, x)
    real(8), intent (in) :: a
    real(8), intent (in) :: x
    real(8) :: tmp
    if ((a * x) <= (-4000000000000.0d0)) then
        tmp = (-2.0d0) - ((4.0d0 / a) / x)
    else
        tmp = a * (x + (x * (a * (x * 0.5d0))))
    end if
    code = tmp
end function
public static double code(double a, double x) {
	double tmp;
	if ((a * x) <= -4000000000000.0) {
		tmp = -2.0 - ((4.0 / a) / x);
	} else {
		tmp = a * (x + (x * (a * (x * 0.5))));
	}
	return tmp;
}
def code(a, x):
	tmp = 0
	if (a * x) <= -4000000000000.0:
		tmp = -2.0 - ((4.0 / a) / x)
	else:
		tmp = a * (x + (x * (a * (x * 0.5))))
	return tmp
function code(a, x)
	tmp = 0.0
	if (Float64(a * x) <= -4000000000000.0)
		tmp = Float64(-2.0 - Float64(Float64(4.0 / a) / x));
	else
		tmp = Float64(a * Float64(x + Float64(x * Float64(a * Float64(x * 0.5)))));
	end
	return tmp
end
function tmp_2 = code(a, x)
	tmp = 0.0;
	if ((a * x) <= -4000000000000.0)
		tmp = -2.0 - ((4.0 / a) / x);
	else
		tmp = a * (x + (x * (a * (x * 0.5))));
	end
	tmp_2 = tmp;
end
code[a_, x_] := If[LessEqual[N[(a * x), $MachinePrecision], -4000000000000.0], N[(-2.0 - N[(N[(4.0 / a), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision], N[(a * N[(x + N[(x * N[(a * N[(x * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \cdot x \leq -4000000000000:\\
\;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\

\mathbf{else}:\\
\;\;\;\;a \cdot \left(x + x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 a x) < -4e12

    1. Initial program 100.0%

      \[e^{a \cdot x} - 1 \]
    2. Step-by-step derivation
      1. expm1-def100.0%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    4. Taylor expanded in a around 0 0.5%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative0.5%

        \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
      2. associate-*r*0.5%

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow20.5%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*0.9%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out1.1%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative1.1%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative1.1%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow21.1%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*1.1%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified1.1%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. distribute-lft-in0.9%

        \[\leadsto \color{blue}{x \cdot a + x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      2. flip-+0.6%

        \[\leadsto \color{blue}{\frac{\left(x \cdot a\right) \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)}} \]
      3. *-commutative0.6%

        \[\leadsto \frac{\color{blue}{\left(a \cdot x\right)} \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      4. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \color{blue}{\left(a \cdot x\right)} - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      5. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      6. associate-*l*0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      7. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      8. associate-*l*0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      9. *-commutative0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{a \cdot x} - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      10. *-commutative0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}} \]
      11. associate-*l*0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
    8. Applied egg-rr0.4%

      \[\leadsto \color{blue}{\frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
    9. Taylor expanded in a around 0 5.0%

      \[\leadsto \frac{\color{blue}{{a}^{2} \cdot {x}^{2}}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    10. Step-by-step derivation
      1. unpow25.0%

        \[\leadsto \frac{\color{blue}{\left(a \cdot a\right)} \cdot {x}^{2}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
      2. unpow25.0%

        \[\leadsto \frac{\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    11. Simplified5.0%

      \[\leadsto \frac{\color{blue}{\left(a \cdot a\right) \cdot \left(x \cdot x\right)}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    12. Taylor expanded in a around inf 18.8%

      \[\leadsto \color{blue}{-\left(2 + 4 \cdot \frac{1}{a \cdot x}\right)} \]
    13. Step-by-step derivation
      1. distribute-neg-in18.8%

        \[\leadsto \color{blue}{\left(-2\right) + \left(-4 \cdot \frac{1}{a \cdot x}\right)} \]
      2. unsub-neg18.8%

        \[\leadsto \color{blue}{\left(-2\right) - 4 \cdot \frac{1}{a \cdot x}} \]
      3. metadata-eval18.8%

        \[\leadsto \color{blue}{-2} - 4 \cdot \frac{1}{a \cdot x} \]
      4. associate-*r/18.8%

        \[\leadsto -2 - \color{blue}{\frac{4 \cdot 1}{a \cdot x}} \]
      5. metadata-eval18.8%

        \[\leadsto -2 - \frac{\color{blue}{4}}{a \cdot x} \]
      6. associate-/r*18.8%

        \[\leadsto -2 - \color{blue}{\frac{\frac{4}{a}}{x}} \]
    14. Simplified18.8%

      \[\leadsto \color{blue}{-2 - \frac{\frac{4}{a}}{x}} \]

    if -4e12 < (*.f64 a x)

    1. Initial program 53.2%

      \[e^{a \cdot x} - 1 \]
    2. Step-by-step derivation
      1. expm1-def99.9%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    4. Taylor expanded in a around 0 80.1%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. *-commutative80.1%

        \[\leadsto \color{blue}{\left({a}^{2} \cdot {x}^{2}\right) \cdot 0.5} + a \cdot x \]
      2. associate-*l*80.1%

        \[\leadsto \color{blue}{{a}^{2} \cdot \left({x}^{2} \cdot 0.5\right)} + a \cdot x \]
      3. unpow280.1%

        \[\leadsto \color{blue}{\left(a \cdot a\right)} \cdot \left({x}^{2} \cdot 0.5\right) + a \cdot x \]
      4. associate-*l*86.3%

        \[\leadsto \color{blue}{a \cdot \left(a \cdot \left({x}^{2} \cdot 0.5\right)\right)} + a \cdot x \]
      5. distribute-lft-out86.3%

        \[\leadsto \color{blue}{a \cdot \left(a \cdot \left({x}^{2} \cdot 0.5\right) + x\right)} \]
      6. unpow286.3%

        \[\leadsto a \cdot \left(a \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot 0.5\right) + x\right) \]
      7. associate-*l*86.3%

        \[\leadsto a \cdot \left(a \cdot \color{blue}{\left(x \cdot \left(x \cdot 0.5\right)\right)} + x\right) \]
    6. Simplified86.3%

      \[\leadsto \color{blue}{a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right) + x\right)} \]
    7. Step-by-step derivation
      1. distribute-lft-in86.3%

        \[\leadsto \color{blue}{a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right)\right) + a \cdot x} \]
      2. *-commutative86.3%

        \[\leadsto a \cdot \color{blue}{\left(\left(x \cdot \left(x \cdot 0.5\right)\right) \cdot a\right)} + a \cdot x \]
      3. associate-*l*86.1%

        \[\leadsto a \cdot \color{blue}{\left(x \cdot \left(\left(x \cdot 0.5\right) \cdot a\right)\right)} + a \cdot x \]
    8. Applied egg-rr86.1%

      \[\leadsto \color{blue}{a \cdot \left(x \cdot \left(\left(x \cdot 0.5\right) \cdot a\right)\right) + a \cdot x} \]
    9. Step-by-step derivation
      1. +-commutative86.1%

        \[\leadsto \color{blue}{a \cdot x + a \cdot \left(x \cdot \left(\left(x \cdot 0.5\right) \cdot a\right)\right)} \]
      2. distribute-lft-out86.1%

        \[\leadsto \color{blue}{a \cdot \left(x + x \cdot \left(\left(x \cdot 0.5\right) \cdot a\right)\right)} \]
      3. *-commutative86.1%

        \[\leadsto a \cdot \left(x + x \cdot \color{blue}{\left(a \cdot \left(x \cdot 0.5\right)\right)}\right) \]
    10. Applied egg-rr86.1%

      \[\leadsto \color{blue}{a \cdot \left(x + x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification70.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \cdot x \leq -4000000000000:\\ \;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\ \mathbf{else}:\\ \;\;\;\;a \cdot \left(x + x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)\\ \end{array} \]

Alternative 6: 60.1% accurate, 9.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot x \leq -4000000000000:\\ \;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\ \mathbf{else}:\\ \;\;\;\;a \cdot x\\ \end{array} \end{array} \]
(FPCore (a x)
 :precision binary64
 (if (<= (* a x) -4000000000000.0) (- -2.0 (/ (/ 4.0 a) x)) (* a x)))
double code(double a, double x) {
	double tmp;
	if ((a * x) <= -4000000000000.0) {
		tmp = -2.0 - ((4.0 / a) / x);
	} else {
		tmp = a * x;
	}
	return tmp;
}
real(8) function code(a, x)
    real(8), intent (in) :: a
    real(8), intent (in) :: x
    real(8) :: tmp
    if ((a * x) <= (-4000000000000.0d0)) then
        tmp = (-2.0d0) - ((4.0d0 / a) / x)
    else
        tmp = a * x
    end if
    code = tmp
end function
public static double code(double a, double x) {
	double tmp;
	if ((a * x) <= -4000000000000.0) {
		tmp = -2.0 - ((4.0 / a) / x);
	} else {
		tmp = a * x;
	}
	return tmp;
}
def code(a, x):
	tmp = 0
	if (a * x) <= -4000000000000.0:
		tmp = -2.0 - ((4.0 / a) / x)
	else:
		tmp = a * x
	return tmp
function code(a, x)
	tmp = 0.0
	if (Float64(a * x) <= -4000000000000.0)
		tmp = Float64(-2.0 - Float64(Float64(4.0 / a) / x));
	else
		tmp = Float64(a * x);
	end
	return tmp
end
function tmp_2 = code(a, x)
	tmp = 0.0;
	if ((a * x) <= -4000000000000.0)
		tmp = -2.0 - ((4.0 / a) / x);
	else
		tmp = a * x;
	end
	tmp_2 = tmp;
end
code[a_, x_] := If[LessEqual[N[(a * x), $MachinePrecision], -4000000000000.0], N[(-2.0 - N[(N[(4.0 / a), $MachinePrecision] / x), $MachinePrecision]), $MachinePrecision], N[(a * x), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \cdot x \leq -4000000000000:\\
\;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\

\mathbf{else}:\\
\;\;\;\;a \cdot x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 a x) < -4e12

    1. Initial program 100.0%

      \[e^{a \cdot x} - 1 \]
    2. Step-by-step derivation
      1. expm1-def100.0%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    4. Taylor expanded in a around 0 0.5%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative0.5%

        \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
      2. associate-*r*0.5%

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow20.5%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*0.9%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out1.1%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative1.1%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative1.1%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow21.1%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*1.1%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified1.1%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. distribute-lft-in0.9%

        \[\leadsto \color{blue}{x \cdot a + x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      2. flip-+0.6%

        \[\leadsto \color{blue}{\frac{\left(x \cdot a\right) \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)}} \]
      3. *-commutative0.6%

        \[\leadsto \frac{\color{blue}{\left(a \cdot x\right)} \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      4. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \color{blue}{\left(a \cdot x\right)} - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      5. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      6. associate-*l*0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      7. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      8. associate-*l*0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      9. *-commutative0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{a \cdot x} - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      10. *-commutative0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}} \]
      11. associate-*l*0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
    8. Applied egg-rr0.4%

      \[\leadsto \color{blue}{\frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
    9. Taylor expanded in a around 0 5.0%

      \[\leadsto \frac{\color{blue}{{a}^{2} \cdot {x}^{2}}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    10. Step-by-step derivation
      1. unpow25.0%

        \[\leadsto \frac{\color{blue}{\left(a \cdot a\right)} \cdot {x}^{2}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
      2. unpow25.0%

        \[\leadsto \frac{\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    11. Simplified5.0%

      \[\leadsto \frac{\color{blue}{\left(a \cdot a\right) \cdot \left(x \cdot x\right)}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    12. Taylor expanded in a around inf 18.8%

      \[\leadsto \color{blue}{-\left(2 + 4 \cdot \frac{1}{a \cdot x}\right)} \]
    13. Step-by-step derivation
      1. distribute-neg-in18.8%

        \[\leadsto \color{blue}{\left(-2\right) + \left(-4 \cdot \frac{1}{a \cdot x}\right)} \]
      2. unsub-neg18.8%

        \[\leadsto \color{blue}{\left(-2\right) - 4 \cdot \frac{1}{a \cdot x}} \]
      3. metadata-eval18.8%

        \[\leadsto \color{blue}{-2} - 4 \cdot \frac{1}{a \cdot x} \]
      4. associate-*r/18.8%

        \[\leadsto -2 - \color{blue}{\frac{4 \cdot 1}{a \cdot x}} \]
      5. metadata-eval18.8%

        \[\leadsto -2 - \frac{\color{blue}{4}}{a \cdot x} \]
      6. associate-/r*18.8%

        \[\leadsto -2 - \color{blue}{\frac{\frac{4}{a}}{x}} \]
    14. Simplified18.8%

      \[\leadsto \color{blue}{-2 - \frac{\frac{4}{a}}{x}} \]

    if -4e12 < (*.f64 a x)

    1. Initial program 53.2%

      \[e^{a \cdot x} - 1 \]
    2. Step-by-step derivation
      1. expm1-def99.9%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    4. Taylor expanded in a around 0 70.3%

      \[\leadsto \color{blue}{a \cdot x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification58.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \cdot x \leq -4000000000000:\\ \;\;\;\;-2 - \frac{\frac{4}{a}}{x}\\ \mathbf{else}:\\ \;\;\;\;a \cdot x\\ \end{array} \]

Alternative 7: 60.2% accurate, 14.9× speedup?

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

\\
\begin{array}{l}
\mathbf{if}\;a \cdot x \leq -2:\\
\;\;\;\;-2\\

\mathbf{else}:\\
\;\;\;\;a \cdot x\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (*.f64 a x) < -2

    1. Initial program 100.0%

      \[e^{a \cdot x} - 1 \]
    2. Step-by-step derivation
      1. expm1-def100.0%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    3. Simplified100.0%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    4. Taylor expanded in a around 0 0.5%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative0.5%

        \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
      2. associate-*r*0.5%

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow20.5%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*0.9%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out1.1%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative1.1%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative1.1%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow21.1%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*1.1%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified1.1%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. distribute-lft-in0.9%

        \[\leadsto \color{blue}{x \cdot a + x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      2. flip-+0.6%

        \[\leadsto \color{blue}{\frac{\left(x \cdot a\right) \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)}} \]
      3. *-commutative0.6%

        \[\leadsto \frac{\color{blue}{\left(a \cdot x\right)} \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      4. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \color{blue}{\left(a \cdot x\right)} - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      5. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      6. associate-*l*0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      7. *-commutative0.6%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      8. associate-*l*0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      9. *-commutative0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{a \cdot x} - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
      10. *-commutative0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}} \]
      11. associate-*l*0.4%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
    8. Applied egg-rr0.4%

      \[\leadsto \color{blue}{\frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
    9. Taylor expanded in a around 0 5.0%

      \[\leadsto \frac{\color{blue}{{a}^{2} \cdot {x}^{2}}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    10. Step-by-step derivation
      1. unpow25.0%

        \[\leadsto \frac{\color{blue}{\left(a \cdot a\right)} \cdot {x}^{2}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
      2. unpow25.0%

        \[\leadsto \frac{\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    11. Simplified5.0%

      \[\leadsto \frac{\color{blue}{\left(a \cdot a\right) \cdot \left(x \cdot x\right)}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    12. Taylor expanded in a around inf 18.8%

      \[\leadsto \color{blue}{-2} \]

    if -2 < (*.f64 a x)

    1. Initial program 53.2%

      \[e^{a \cdot x} - 1 \]
    2. Step-by-step derivation
      1. expm1-def99.9%

        \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    3. Simplified99.9%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
    4. Taylor expanded in a around 0 70.3%

      \[\leadsto \color{blue}{a \cdot x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification58.4%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \cdot x \leq -2:\\ \;\;\;\;-2\\ \mathbf{else}:\\ \;\;\;\;a \cdot x\\ \end{array} \]

Alternative 8: 6.6% accurate, 105.0× speedup?

\[\begin{array}{l} \\ -2 \end{array} \]
(FPCore (a x) :precision binary64 -2.0)
double code(double a, double x) {
	return -2.0;
}
real(8) function code(a, x)
    real(8), intent (in) :: a
    real(8), intent (in) :: x
    code = -2.0d0
end function
public static double code(double a, double x) {
	return -2.0;
}
def code(a, x):
	return -2.0
function code(a, x)
	return -2.0
end
function tmp = code(a, x)
	tmp = -2.0;
end
code[a_, x_] := -2.0
\begin{array}{l}

\\
-2
\end{array}
Derivation
  1. Initial program 64.0%

    \[e^{a \cdot x} - 1 \]
  2. Step-by-step derivation
    1. expm1-def99.9%

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
  3. Simplified99.9%

    \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
  4. Taylor expanded in a around 0 61.8%

    \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
  5. Step-by-step derivation
    1. +-commutative61.8%

      \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
    2. associate-*r*61.8%

      \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
    3. unpow261.8%

      \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
    4. associate-*r*63.7%

      \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
    5. distribute-rgt-out63.7%

      \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
    6. *-commutative63.7%

      \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
    7. *-commutative63.7%

      \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
    8. unpow263.7%

      \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
    9. associate-*l*63.7%

      \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
  6. Simplified63.7%

    \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
  7. Step-by-step derivation
    1. distribute-lft-in63.7%

      \[\leadsto \color{blue}{x \cdot a + x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    2. flip-+23.5%

      \[\leadsto \color{blue}{\frac{\left(x \cdot a\right) \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)}} \]
    3. *-commutative23.5%

      \[\leadsto \frac{\color{blue}{\left(a \cdot x\right)} \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    4. *-commutative23.5%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \color{blue}{\left(a \cdot x\right)} - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    5. *-commutative23.5%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    6. associate-*l*23.5%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. *-commutative23.5%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    8. associate-*l*23.5%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    9. *-commutative23.5%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{a \cdot x} - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    10. *-commutative23.5%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}} \]
    11. associate-*l*28.5%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
  8. Applied egg-rr28.5%

    \[\leadsto \color{blue}{\frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
  9. Taylor expanded in a around 0 13.2%

    \[\leadsto \frac{\color{blue}{{a}^{2} \cdot {x}^{2}}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
  10. Step-by-step derivation
    1. unpow213.2%

      \[\leadsto \frac{\color{blue}{\left(a \cdot a\right)} \cdot {x}^{2}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
    2. unpow213.2%

      \[\leadsto \frac{\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
  11. Simplified13.2%

    \[\leadsto \frac{\color{blue}{\left(a \cdot a\right) \cdot \left(x \cdot x\right)}}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
  12. Taylor expanded in a around inf 6.5%

    \[\leadsto \color{blue}{-2} \]
  13. Final simplification6.5%

    \[\leadsto -2 \]

Developer target: 99.8% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\left|a \cdot x\right| < 0.1:\\ \;\;\;\;\left(a \cdot x\right) \cdot \left(1 + \left(\frac{a \cdot x}{2} + \frac{{\left(a \cdot x\right)}^{2}}{6}\right)\right)\\ \mathbf{else}:\\ \;\;\;\;e^{a \cdot x} - 1\\ \end{array} \end{array} \]
(FPCore (a x)
 :precision binary64
 (if (< (fabs (* a x)) 0.1)
   (* (* a x) (+ 1.0 (+ (/ (* a x) 2.0) (/ (pow (* a x) 2.0) 6.0))))
   (- (exp (* a x)) 1.0)))
double code(double a, double x) {
	double tmp;
	if (fabs((a * x)) < 0.1) {
		tmp = (a * x) * (1.0 + (((a * x) / 2.0) + (pow((a * x), 2.0) / 6.0)));
	} else {
		tmp = exp((a * x)) - 1.0;
	}
	return tmp;
}
real(8) function code(a, x)
    real(8), intent (in) :: a
    real(8), intent (in) :: x
    real(8) :: tmp
    if (abs((a * x)) < 0.1d0) then
        tmp = (a * x) * (1.0d0 + (((a * x) / 2.0d0) + (((a * x) ** 2.0d0) / 6.0d0)))
    else
        tmp = exp((a * x)) - 1.0d0
    end if
    code = tmp
end function
public static double code(double a, double x) {
	double tmp;
	if (Math.abs((a * x)) < 0.1) {
		tmp = (a * x) * (1.0 + (((a * x) / 2.0) + (Math.pow((a * x), 2.0) / 6.0)));
	} else {
		tmp = Math.exp((a * x)) - 1.0;
	}
	return tmp;
}
def code(a, x):
	tmp = 0
	if math.fabs((a * x)) < 0.1:
		tmp = (a * x) * (1.0 + (((a * x) / 2.0) + (math.pow((a * x), 2.0) / 6.0)))
	else:
		tmp = math.exp((a * x)) - 1.0
	return tmp
function code(a, x)
	tmp = 0.0
	if (abs(Float64(a * x)) < 0.1)
		tmp = Float64(Float64(a * x) * Float64(1.0 + Float64(Float64(Float64(a * x) / 2.0) + Float64((Float64(a * x) ^ 2.0) / 6.0))));
	else
		tmp = Float64(exp(Float64(a * x)) - 1.0);
	end
	return tmp
end
function tmp_2 = code(a, x)
	tmp = 0.0;
	if (abs((a * x)) < 0.1)
		tmp = (a * x) * (1.0 + (((a * x) / 2.0) + (((a * x) ^ 2.0) / 6.0)));
	else
		tmp = exp((a * x)) - 1.0;
	end
	tmp_2 = tmp;
end
code[a_, x_] := If[Less[N[Abs[N[(a * x), $MachinePrecision]], $MachinePrecision], 0.1], N[(N[(a * x), $MachinePrecision] * N[(1.0 + N[(N[(N[(a * x), $MachinePrecision] / 2.0), $MachinePrecision] + N[(N[Power[N[(a * x), $MachinePrecision], 2.0], $MachinePrecision] / 6.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[Exp[N[(a * x), $MachinePrecision]], $MachinePrecision] - 1.0), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\left|a \cdot x\right| < 0.1:\\
\;\;\;\;\left(a \cdot x\right) \cdot \left(1 + \left(\frac{a \cdot x}{2} + \frac{{\left(a \cdot x\right)}^{2}}{6}\right)\right)\\

\mathbf{else}:\\
\;\;\;\;e^{a \cdot x} - 1\\


\end{array}
\end{array}

Reproduce

?
herbie shell --seed 2023201 
(FPCore (a x)
  :name "expax (section 3.5)"
  :precision binary64

  :herbie-target
  (if (< (fabs (* a x)) 0.1) (* (* a x) (+ 1.0 (+ (/ (* a x) 2.0) (/ (pow (* a x) 2.0) 6.0)))) (- (exp (* a x)) 1.0))

  (- (exp (* a x)) 1.0))