expax (section 3.5)

Percentage Accurate: 65.7% → 100.0%
Time: 6.1s
Alternatives: 8
Speedup: 6.1×

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 69.1%

    \[e^{a \cdot x} - 1 \]
  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. Final simplification100.0%

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

Alternative 2: 71.9% accurate, 5.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot x \leq -50:\\ \;\;\;\;-2\\ \mathbf{elif}\;a \cdot x \leq 4 \cdot 10^{-5}:\\ \;\;\;\;a \cdot x + x \cdot \left(a \cdot \left(x \cdot \left(a \cdot 0.5\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\\ \end{array} \end{array} \]
(FPCore (a x)
 :precision binary64
 (if (<= (* a x) -50.0)
   -2.0
   (if (<= (* a x) 4e-5)
     (+ (* a x) (* x (* a (* x (* a 0.5)))))
     (* x (+ a (* x (* a (* a 0.5))))))))
double code(double a, double x) {
	double tmp;
	if ((a * x) <= -50.0) {
		tmp = -2.0;
	} else if ((a * x) <= 4e-5) {
		tmp = (a * x) + (x * (a * (x * (a * 0.5))));
	} else {
		tmp = x * (a + (x * (a * (a * 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) <= (-50.0d0)) then
        tmp = -2.0d0
    else if ((a * x) <= 4d-5) then
        tmp = (a * x) + (x * (a * (x * (a * 0.5d0))))
    else
        tmp = x * (a + (x * (a * (a * 0.5d0))))
    end if
    code = tmp
end function
public static double code(double a, double x) {
	double tmp;
	if ((a * x) <= -50.0) {
		tmp = -2.0;
	} else if ((a * x) <= 4e-5) {
		tmp = (a * x) + (x * (a * (x * (a * 0.5))));
	} else {
		tmp = x * (a + (x * (a * (a * 0.5))));
	}
	return tmp;
}
def code(a, x):
	tmp = 0
	if (a * x) <= -50.0:
		tmp = -2.0
	elif (a * x) <= 4e-5:
		tmp = (a * x) + (x * (a * (x * (a * 0.5))))
	else:
		tmp = x * (a + (x * (a * (a * 0.5))))
	return tmp
function code(a, x)
	tmp = 0.0
	if (Float64(a * x) <= -50.0)
		tmp = -2.0;
	elseif (Float64(a * x) <= 4e-5)
		tmp = Float64(Float64(a * x) + Float64(x * Float64(a * Float64(x * Float64(a * 0.5)))));
	else
		tmp = Float64(x * Float64(a + Float64(x * Float64(a * Float64(a * 0.5)))));
	end
	return tmp
end
function tmp_2 = code(a, x)
	tmp = 0.0;
	if ((a * x) <= -50.0)
		tmp = -2.0;
	elseif ((a * x) <= 4e-5)
		tmp = (a * x) + (x * (a * (x * (a * 0.5))));
	else
		tmp = x * (a + (x * (a * (a * 0.5))));
	end
	tmp_2 = tmp;
end
code[a_, x_] := If[LessEqual[N[(a * x), $MachinePrecision], -50.0], -2.0, If[LessEqual[N[(a * x), $MachinePrecision], 4e-5], N[(N[(a * x), $MachinePrecision] + N[(x * N[(a * N[(x * N[(a * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x * N[(a + N[(x * N[(a * N[(a * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \cdot x \leq -50:\\
\;\;\;\;-2\\

\mathbf{elif}\;a \cdot x \leq 4 \cdot 10^{-5}:\\
\;\;\;\;a \cdot x + x \cdot \left(a \cdot \left(x \cdot \left(a \cdot 0.5\right)\right)\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 a x) < -50

    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 0.6%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative0.6%

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

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow20.6%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*0.8%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out1.0%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative1.0%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative1.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow21.0%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*1.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified1.0%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. distribute-lft-in0.8%

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}} \]
      11. associate-*l*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 inf 0.3%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{-0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)}} \]
    10. Step-by-step derivation
      1. unpow20.3%

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

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{-0.5 \cdot \left(\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}\right)} \]
      3. associate-*r*0.3%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{\left(-0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)}} \]
    11. Simplified0.3%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{\left(-0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)}} \]
    12. Taylor expanded in a around 0 18.8%

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

    if -50 < (*.f64 a x) < 4.00000000000000033e-5

    1. Initial program 33.5%

      \[e^{a \cdot x} - 1 \]
    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 84.0%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative84.0%

        \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
      2. associate-*r*84.0%

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow284.0%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*88.2%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out88.2%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative88.2%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative88.2%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow288.2%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*88.2%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified88.2%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. +-commutative88.2%

        \[\leadsto x \cdot \color{blue}{\left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right) + a\right)} \]
      2. distribute-lft-in88.2%

        \[\leadsto \color{blue}{x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right) + x \cdot a} \]
      3. *-commutative88.2%

        \[\leadsto x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)} + x \cdot a \]
      4. associate-*l*98.7%

        \[\leadsto x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} + x \cdot a \]
      5. *-commutative98.7%

        \[\leadsto x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right) + \color{blue}{a \cdot x} \]
    8. Applied egg-rr98.7%

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

    if 4.00000000000000033e-5 < (*.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 76.9%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative76.9%

        \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
      2. associate-*r*76.9%

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow276.9%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*79.0%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out79.0%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative79.0%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative79.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow279.0%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*79.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified79.0%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification70.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \cdot x \leq -50:\\ \;\;\;\;-2\\ \mathbf{elif}\;a \cdot x \leq 4 \cdot 10^{-5}:\\ \;\;\;\;a \cdot x + x \cdot \left(a \cdot \left(x \cdot \left(a \cdot 0.5\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\\ \end{array} \]

Alternative 3: 72.0% accurate, 5.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot x \leq -50:\\ \;\;\;\;-2\\ \mathbf{elif}\;a \cdot x \leq 100000:\\ \;\;\;\;a \cdot \left(x + x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)\\ \end{array} \end{array} \]
(FPCore (a x)
 :precision binary64
 (if (<= (* a x) -50.0)
   -2.0
   (if (<= (* a x) 100000.0)
     (* a (+ x (* x (* a (* x 0.5)))))
     (* (* 0.5 (* a a)) (* x x)))))
double code(double a, double x) {
	double tmp;
	if ((a * x) <= -50.0) {
		tmp = -2.0;
	} else if ((a * x) <= 100000.0) {
		tmp = a * (x + (x * (a * (x * 0.5))));
	} 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) <= (-50.0d0)) then
        tmp = -2.0d0
    else if ((a * x) <= 100000.0d0) then
        tmp = a * (x + (x * (a * (x * 0.5d0))))
    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) <= -50.0) {
		tmp = -2.0;
	} else if ((a * x) <= 100000.0) {
		tmp = a * (x + (x * (a * (x * 0.5))));
	} else {
		tmp = (0.5 * (a * a)) * (x * x);
	}
	return tmp;
}
def code(a, x):
	tmp = 0
	if (a * x) <= -50.0:
		tmp = -2.0
	elif (a * x) <= 100000.0:
		tmp = a * (x + (x * (a * (x * 0.5))))
	else:
		tmp = (0.5 * (a * a)) * (x * x)
	return tmp
function code(a, x)
	tmp = 0.0
	if (Float64(a * x) <= -50.0)
		tmp = -2.0;
	elseif (Float64(a * x) <= 100000.0)
		tmp = Float64(a * Float64(x + Float64(x * Float64(a * Float64(x * 0.5)))));
	else
		tmp = Float64(Float64(0.5 * Float64(a * a)) * Float64(x * x));
	end
	return tmp
end
function tmp_2 = code(a, x)
	tmp = 0.0;
	if ((a * x) <= -50.0)
		tmp = -2.0;
	elseif ((a * x) <= 100000.0)
		tmp = a * (x + (x * (a * (x * 0.5))));
	else
		tmp = (0.5 * (a * a)) * (x * x);
	end
	tmp_2 = tmp;
end
code[a_, x_] := If[LessEqual[N[(a * x), $MachinePrecision], -50.0], -2.0, If[LessEqual[N[(a * x), $MachinePrecision], 100000.0], N[(a * N[(x + N[(x * N[(a * N[(x * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 * N[(a * a), $MachinePrecision]), $MachinePrecision] * N[(x * x), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \cdot x \leq -50:\\
\;\;\;\;-2\\

\mathbf{elif}\;a \cdot x \leq 100000:\\
\;\;\;\;a \cdot \left(x + x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 a x) < -50

    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 0.6%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative0.6%

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

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow20.6%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*0.8%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out1.0%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative1.0%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative1.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow21.0%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*1.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified1.0%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. distribute-lft-in0.8%

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}} \]
      11. associate-*l*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 inf 0.3%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{-0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)}} \]
    10. Step-by-step derivation
      1. unpow20.3%

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

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{-0.5 \cdot \left(\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}\right)} \]
      3. associate-*r*0.3%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{\left(-0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)}} \]
    11. Simplified0.3%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{\left(-0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)}} \]
    12. Taylor expanded in a around 0 18.8%

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

    if -50 < (*.f64 a x) < 1e5

    1. Initial program 34.1%

      \[e^{a \cdot x} - 1 \]
    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 83.3%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative83.3%

        \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
      2. associate-*r*83.3%

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow283.3%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*88.3%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out88.3%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative88.3%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative88.3%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow288.3%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*88.3%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified88.3%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. +-commutative88.3%

        \[\leadsto x \cdot \color{blue}{\left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right) + a\right)} \]
      2. distribute-lft-in88.3%

        \[\leadsto \color{blue}{x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right) + x \cdot a} \]
      3. *-commutative88.3%

        \[\leadsto x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)} + x \cdot a \]
      4. associate-*l*97.9%

        \[\leadsto x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} + x \cdot a \]
      5. *-commutative97.9%

        \[\leadsto x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right) + \color{blue}{a \cdot x} \]
    8. Applied egg-rr97.9%

      \[\leadsto \color{blue}{x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right) + a \cdot x} \]
    9. Step-by-step derivation
      1. +-commutative97.9%

        \[\leadsto \color{blue}{a \cdot x + x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
      2. fma-def97.9%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a, x, x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)} \]
      3. associate-*r*97.9%

        \[\leadsto \mathsf{fma}\left(a, x, \color{blue}{\left(x \cdot a\right) \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)}\right) \]
      4. *-commutative97.9%

        \[\leadsto \mathsf{fma}\left(a, x, \color{blue}{\left(a \cdot x\right)} \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right) \]
      5. associate-*l*97.9%

        \[\leadsto \mathsf{fma}\left(a, x, \color{blue}{a \cdot \left(x \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right) \]
      6. associate-*l*97.9%

        \[\leadsto \mathsf{fma}\left(a, x, a \cdot \left(x \cdot \color{blue}{\left(a \cdot \left(0.5 \cdot x\right)\right)}\right)\right) \]
      7. *-commutative97.9%

        \[\leadsto \mathsf{fma}\left(a, x, a \cdot \left(x \cdot \left(a \cdot \color{blue}{\left(x \cdot 0.5\right)}\right)\right)\right) \]
    10. Applied egg-rr97.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a, x, a \cdot \left(x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)\right)} \]
    11. Step-by-step derivation
      1. fma-def97.9%

        \[\leadsto \color{blue}{a \cdot x + a \cdot \left(x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)} \]
      2. +-commutative97.9%

        \[\leadsto \color{blue}{a \cdot \left(x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right) + a \cdot x} \]
      3. distribute-lft-out97.9%

        \[\leadsto \color{blue}{a \cdot \left(x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right) + x\right)} \]
    12. Simplified97.9%

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

    if 1e5 < (*.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 78.2%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative78.2%

        \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
      2. associate-*r*78.2%

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow278.2%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*78.6%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out78.6%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative78.6%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative78.6%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow278.6%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*78.6%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified78.6%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. +-commutative78.6%

        \[\leadsto x \cdot \color{blue}{\left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right) + a\right)} \]
      2. distribute-lft-in78.6%

        \[\leadsto \color{blue}{x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right) + x \cdot a} \]
      3. *-commutative78.6%

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

        \[\leadsto x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} + x \cdot a \]
      5. *-commutative70.9%

        \[\leadsto x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right) + \color{blue}{a \cdot x} \]
    8. Applied egg-rr70.9%

      \[\leadsto \color{blue}{x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right) + a \cdot x} \]
    9. Taylor expanded in x around inf 78.2%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
    10. Step-by-step derivation
      1. unpow278.2%

        \[\leadsto 0.5 \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot {x}^{2}\right) \]
      2. unpow278.2%

        \[\leadsto 0.5 \cdot \left(\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}\right) \]
      3. associate-*r*78.2%

        \[\leadsto \color{blue}{\left(0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)} \]
    11. Simplified78.2%

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

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \cdot x \leq -50:\\ \;\;\;\;-2\\ \mathbf{elif}\;a \cdot x \leq 100000:\\ \;\;\;\;a \cdot \left(x + x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;\left(0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)\\ \end{array} \]

Alternative 4: 71.9% accurate, 5.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot x \leq -50:\\ \;\;\;\;-2\\ \mathbf{elif}\;a \cdot x \leq 4 \cdot 10^{-5}:\\ \;\;\;\;a \cdot \left(x + x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\\ \end{array} \end{array} \]
(FPCore (a x)
 :precision binary64
 (if (<= (* a x) -50.0)
   -2.0
   (if (<= (* a x) 4e-5)
     (* a (+ x (* x (* a (* x 0.5)))))
     (* x (+ a (* x (* a (* a 0.5))))))))
double code(double a, double x) {
	double tmp;
	if ((a * x) <= -50.0) {
		tmp = -2.0;
	} else if ((a * x) <= 4e-5) {
		tmp = a * (x + (x * (a * (x * 0.5))));
	} else {
		tmp = x * (a + (x * (a * (a * 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) <= (-50.0d0)) then
        tmp = -2.0d0
    else if ((a * x) <= 4d-5) then
        tmp = a * (x + (x * (a * (x * 0.5d0))))
    else
        tmp = x * (a + (x * (a * (a * 0.5d0))))
    end if
    code = tmp
end function
public static double code(double a, double x) {
	double tmp;
	if ((a * x) <= -50.0) {
		tmp = -2.0;
	} else if ((a * x) <= 4e-5) {
		tmp = a * (x + (x * (a * (x * 0.5))));
	} else {
		tmp = x * (a + (x * (a * (a * 0.5))));
	}
	return tmp;
}
def code(a, x):
	tmp = 0
	if (a * x) <= -50.0:
		tmp = -2.0
	elif (a * x) <= 4e-5:
		tmp = a * (x + (x * (a * (x * 0.5))))
	else:
		tmp = x * (a + (x * (a * (a * 0.5))))
	return tmp
function code(a, x)
	tmp = 0.0
	if (Float64(a * x) <= -50.0)
		tmp = -2.0;
	elseif (Float64(a * x) <= 4e-5)
		tmp = Float64(a * Float64(x + Float64(x * Float64(a * Float64(x * 0.5)))));
	else
		tmp = Float64(x * Float64(a + Float64(x * Float64(a * Float64(a * 0.5)))));
	end
	return tmp
end
function tmp_2 = code(a, x)
	tmp = 0.0;
	if ((a * x) <= -50.0)
		tmp = -2.0;
	elseif ((a * x) <= 4e-5)
		tmp = a * (x + (x * (a * (x * 0.5))));
	else
		tmp = x * (a + (x * (a * (a * 0.5))));
	end
	tmp_2 = tmp;
end
code[a_, x_] := If[LessEqual[N[(a * x), $MachinePrecision], -50.0], -2.0, If[LessEqual[N[(a * x), $MachinePrecision], 4e-5], N[(a * N[(x + N[(x * N[(a * N[(x * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(x * N[(a + N[(x * N[(a * N[(a * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \cdot x \leq -50:\\
\;\;\;\;-2\\

\mathbf{elif}\;a \cdot x \leq 4 \cdot 10^{-5}:\\
\;\;\;\;a \cdot \left(x + x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 a x) < -50

    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 0.6%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative0.6%

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

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow20.6%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*0.8%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out1.0%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative1.0%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative1.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow21.0%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*1.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified1.0%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. distribute-lft-in0.8%

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}} \]
      11. associate-*l*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 inf 0.3%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{-0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)}} \]
    10. Step-by-step derivation
      1. unpow20.3%

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

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{-0.5 \cdot \left(\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}\right)} \]
      3. associate-*r*0.3%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{\left(-0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)}} \]
    11. Simplified0.3%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{\left(-0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)}} \]
    12. Taylor expanded in a around 0 18.8%

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

    if -50 < (*.f64 a x) < 4.00000000000000033e-5

    1. Initial program 33.5%

      \[e^{a \cdot x} - 1 \]
    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 84.0%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative84.0%

        \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
      2. associate-*r*84.0%

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow284.0%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*88.2%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out88.2%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative88.2%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative88.2%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow288.2%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*88.2%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified88.2%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. +-commutative88.2%

        \[\leadsto x \cdot \color{blue}{\left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right) + a\right)} \]
      2. distribute-lft-in88.2%

        \[\leadsto \color{blue}{x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right) + x \cdot a} \]
      3. *-commutative88.2%

        \[\leadsto x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)} + x \cdot a \]
      4. associate-*l*98.7%

        \[\leadsto x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} + x \cdot a \]
      5. *-commutative98.7%

        \[\leadsto x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right) + \color{blue}{a \cdot x} \]
    8. Applied egg-rr98.7%

      \[\leadsto \color{blue}{x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right) + a \cdot x} \]
    9. Step-by-step derivation
      1. +-commutative98.7%

        \[\leadsto \color{blue}{a \cdot x + x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} \]
      2. fma-def98.7%

        \[\leadsto \color{blue}{\mathsf{fma}\left(a, x, x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)} \]
      3. associate-*r*98.7%

        \[\leadsto \mathsf{fma}\left(a, x, \color{blue}{\left(x \cdot a\right) \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)}\right) \]
      4. *-commutative98.7%

        \[\leadsto \mathsf{fma}\left(a, x, \color{blue}{\left(a \cdot x\right)} \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right) \]
      5. associate-*l*98.7%

        \[\leadsto \mathsf{fma}\left(a, x, \color{blue}{a \cdot \left(x \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right) \]
      6. associate-*l*98.7%

        \[\leadsto \mathsf{fma}\left(a, x, a \cdot \left(x \cdot \color{blue}{\left(a \cdot \left(0.5 \cdot x\right)\right)}\right)\right) \]
      7. *-commutative98.7%

        \[\leadsto \mathsf{fma}\left(a, x, a \cdot \left(x \cdot \left(a \cdot \color{blue}{\left(x \cdot 0.5\right)}\right)\right)\right) \]
    10. Applied egg-rr98.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(a, x, a \cdot \left(x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)\right)} \]
    11. Step-by-step derivation
      1. fma-def98.7%

        \[\leadsto \color{blue}{a \cdot x + a \cdot \left(x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)} \]
      2. +-commutative98.7%

        \[\leadsto \color{blue}{a \cdot \left(x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right) + a \cdot x} \]
      3. distribute-lft-out98.7%

        \[\leadsto \color{blue}{a \cdot \left(x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right) + x\right)} \]
    12. Simplified98.7%

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

    if 4.00000000000000033e-5 < (*.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 76.9%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative76.9%

        \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
      2. associate-*r*76.9%

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow276.9%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*79.0%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out79.0%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative79.0%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative79.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow279.0%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*79.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified79.0%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification70.7%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \cdot x \leq -50:\\ \;\;\;\;-2\\ \mathbf{elif}\;a \cdot x \leq 4 \cdot 10^{-5}:\\ \;\;\;\;a \cdot \left(x + x \cdot \left(a \cdot \left(x \cdot 0.5\right)\right)\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\\ \end{array} \]

Alternative 5: 71.6% accurate, 6.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot x \leq -50:\\ \;\;\;\;-2\\ \mathbf{elif}\;a \cdot x \leq 100000:\\ \;\;\;\;a \cdot x\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \left(a \cdot \left(a \cdot \left(x \cdot x\right)\right)\right)\\ \end{array} \end{array} \]
(FPCore (a x)
 :precision binary64
 (if (<= (* a x) -50.0)
   -2.0
   (if (<= (* a x) 100000.0) (* a x) (* 0.5 (* a (* a (* x x)))))))
double code(double a, double x) {
	double tmp;
	if ((a * x) <= -50.0) {
		tmp = -2.0;
	} else if ((a * x) <= 100000.0) {
		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) <= (-50.0d0)) then
        tmp = -2.0d0
    else if ((a * x) <= 100000.0d0) 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) <= -50.0) {
		tmp = -2.0;
	} else if ((a * x) <= 100000.0) {
		tmp = a * x;
	} else {
		tmp = 0.5 * (a * (a * (x * x)));
	}
	return tmp;
}
def code(a, x):
	tmp = 0
	if (a * x) <= -50.0:
		tmp = -2.0
	elif (a * x) <= 100000.0:
		tmp = a * x
	else:
		tmp = 0.5 * (a * (a * (x * x)))
	return tmp
function code(a, x)
	tmp = 0.0
	if (Float64(a * x) <= -50.0)
		tmp = -2.0;
	elseif (Float64(a * x) <= 100000.0)
		tmp = Float64(a * x);
	else
		tmp = Float64(0.5 * Float64(a * Float64(a * Float64(x * x))));
	end
	return tmp
end
function tmp_2 = code(a, x)
	tmp = 0.0;
	if ((a * x) <= -50.0)
		tmp = -2.0;
	elseif ((a * x) <= 100000.0)
		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], -50.0], -2.0, If[LessEqual[N[(a * x), $MachinePrecision], 100000.0], N[(a * x), $MachinePrecision], N[(0.5 * N[(a * N[(a * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \cdot x \leq -50:\\
\;\;\;\;-2\\

\mathbf{elif}\;a \cdot x \leq 100000:\\
\;\;\;\;a \cdot x\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 a x) < -50

    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 0.6%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative0.6%

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

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow20.6%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*0.8%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out1.0%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative1.0%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative1.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow21.0%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*1.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified1.0%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. distribute-lft-in0.8%

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}} \]
      11. associate-*l*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 inf 0.3%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{-0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)}} \]
    10. Step-by-step derivation
      1. unpow20.3%

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

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{-0.5 \cdot \left(\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}\right)} \]
      3. associate-*r*0.3%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{\left(-0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)}} \]
    11. Simplified0.3%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{\left(-0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)}} \]
    12. Taylor expanded in a around 0 18.8%

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

    if -50 < (*.f64 a x) < 1e5

    1. Initial program 34.1%

      \[e^{a \cdot x} - 1 \]
    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 96.5%

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

    if 1e5 < (*.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 78.2%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. *-commutative78.2%

        \[\leadsto \color{blue}{\left({a}^{2} \cdot {x}^{2}\right) \cdot 0.5} + a \cdot x \]
      2. associate-*l*78.2%

        \[\leadsto \color{blue}{{a}^{2} \cdot \left({x}^{2} \cdot 0.5\right)} + a \cdot x \]
      3. unpow278.2%

        \[\leadsto \color{blue}{\left(a \cdot a\right)} \cdot \left({x}^{2} \cdot 0.5\right) + a \cdot x \]
      4. associate-*l*77.0%

        \[\leadsto \color{blue}{a \cdot \left(a \cdot \left({x}^{2} \cdot 0.5\right)\right)} + a \cdot x \]
      5. distribute-lft-out77.0%

        \[\leadsto \color{blue}{a \cdot \left(a \cdot \left({x}^{2} \cdot 0.5\right) + x\right)} \]
      6. unpow277.0%

        \[\leadsto a \cdot \left(a \cdot \left(\color{blue}{\left(x \cdot x\right)} \cdot 0.5\right) + x\right) \]
      7. associate-*l*77.0%

        \[\leadsto a \cdot \left(a \cdot \color{blue}{\left(x \cdot \left(x \cdot 0.5\right)\right)} + x\right) \]
    6. Simplified77.0%

      \[\leadsto \color{blue}{a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right) + x\right)} \]
    7. Taylor expanded in a around inf 78.2%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
    8. Step-by-step derivation
      1. unpow278.2%

        \[\leadsto 0.5 \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot {x}^{2}\right) \]
      2. unpow278.2%

        \[\leadsto 0.5 \cdot \left(\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}\right) \]
      3. associate-*r*76.9%

        \[\leadsto 0.5 \cdot \color{blue}{\left(a \cdot \left(a \cdot \left(x \cdot x\right)\right)\right)} \]
    9. Simplified76.9%

      \[\leadsto \color{blue}{0.5 \cdot \left(a \cdot \left(a \cdot \left(x \cdot x\right)\right)\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification69.3%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \cdot x \leq -50:\\ \;\;\;\;-2\\ \mathbf{elif}\;a \cdot x \leq 100000:\\ \;\;\;\;a \cdot x\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \left(a \cdot \left(a \cdot \left(x \cdot x\right)\right)\right)\\ \end{array} \]

Alternative 6: 71.5% accurate, 6.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot x \leq -50:\\ \;\;\;\;-2\\ \mathbf{elif}\;a \cdot x \leq 100000:\\ \;\;\;\;a \cdot x\\ \mathbf{else}:\\ \;\;\;\;\left(0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)\\ \end{array} \end{array} \]
(FPCore (a x)
 :precision binary64
 (if (<= (* a x) -50.0)
   -2.0
   (if (<= (* a x) 100000.0) (* a x) (* (* 0.5 (* a a)) (* x x)))))
double code(double a, double x) {
	double tmp;
	if ((a * x) <= -50.0) {
		tmp = -2.0;
	} else if ((a * x) <= 100000.0) {
		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) <= (-50.0d0)) then
        tmp = -2.0d0
    else if ((a * x) <= 100000.0d0) 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) <= -50.0) {
		tmp = -2.0;
	} else if ((a * x) <= 100000.0) {
		tmp = a * x;
	} else {
		tmp = (0.5 * (a * a)) * (x * x);
	}
	return tmp;
}
def code(a, x):
	tmp = 0
	if (a * x) <= -50.0:
		tmp = -2.0
	elif (a * x) <= 100000.0:
		tmp = a * x
	else:
		tmp = (0.5 * (a * a)) * (x * x)
	return tmp
function code(a, x)
	tmp = 0.0
	if (Float64(a * x) <= -50.0)
		tmp = -2.0;
	elseif (Float64(a * x) <= 100000.0)
		tmp = Float64(a * x);
	else
		tmp = Float64(Float64(0.5 * Float64(a * a)) * Float64(x * x));
	end
	return tmp
end
function tmp_2 = code(a, x)
	tmp = 0.0;
	if ((a * x) <= -50.0)
		tmp = -2.0;
	elseif ((a * x) <= 100000.0)
		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], -50.0], -2.0, If[LessEqual[N[(a * x), $MachinePrecision], 100000.0], N[(a * x), $MachinePrecision], N[(N[(0.5 * N[(a * a), $MachinePrecision]), $MachinePrecision] * N[(x * x), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \cdot x \leq -50:\\
\;\;\;\;-2\\

\mathbf{elif}\;a \cdot x \leq 100000:\\
\;\;\;\;a \cdot x\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 a x) < -50

    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 0.6%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative0.6%

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

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow20.6%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*0.8%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out1.0%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative1.0%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative1.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow21.0%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*1.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified1.0%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. distribute-lft-in0.8%

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}} \]
      11. associate-*l*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 inf 0.3%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{-0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)}} \]
    10. Step-by-step derivation
      1. unpow20.3%

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

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{-0.5 \cdot \left(\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}\right)} \]
      3. associate-*r*0.3%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{\left(-0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)}} \]
    11. Simplified0.3%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{\left(-0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)}} \]
    12. Taylor expanded in a around 0 18.8%

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

    if -50 < (*.f64 a x) < 1e5

    1. Initial program 34.1%

      \[e^{a \cdot x} - 1 \]
    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 96.5%

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

    if 1e5 < (*.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 78.2%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative78.2%

        \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
      2. associate-*r*78.2%

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow278.2%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*78.6%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out78.6%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative78.6%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative78.6%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow278.6%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*78.6%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified78.6%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. +-commutative78.6%

        \[\leadsto x \cdot \color{blue}{\left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right) + a\right)} \]
      2. distribute-lft-in78.6%

        \[\leadsto \color{blue}{x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right) + x \cdot a} \]
      3. *-commutative78.6%

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

        \[\leadsto x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)} + x \cdot a \]
      5. *-commutative70.9%

        \[\leadsto x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right) + \color{blue}{a \cdot x} \]
    8. Applied egg-rr70.9%

      \[\leadsto \color{blue}{x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right) + a \cdot x} \]
    9. Taylor expanded in x around inf 78.2%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
    10. Step-by-step derivation
      1. unpow278.2%

        \[\leadsto 0.5 \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot {x}^{2}\right) \]
      2. unpow278.2%

        \[\leadsto 0.5 \cdot \left(\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}\right) \]
      3. associate-*r*78.2%

        \[\leadsto \color{blue}{\left(0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)} \]
    11. Simplified78.2%

      \[\leadsto \color{blue}{\left(0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification69.6%

    \[\leadsto \begin{array}{l} \mathbf{if}\;a \cdot x \leq -50:\\ \;\;\;\;-2\\ \mathbf{elif}\;a \cdot x \leq 100000:\\ \;\;\;\;a \cdot x\\ \mathbf{else}:\\ \;\;\;\;\left(0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)\\ \end{array} \]

Alternative 7: 60.9% 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 0.6%

      \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
    5. Step-by-step derivation
      1. +-commutative0.6%

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

        \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
      3. unpow20.6%

        \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
      4. associate-*r*0.8%

        \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
      5. distribute-rgt-out1.0%

        \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
      6. *-commutative1.0%

        \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
      7. *-commutative1.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
      8. unpow21.0%

        \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
      9. associate-*l*1.0%

        \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
    6. Simplified1.0%

      \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. Step-by-step derivation
      1. distribute-lft-in0.8%

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

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

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

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

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

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

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

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

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

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}} \]
      11. associate-*l*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 inf 0.3%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{-0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)}} \]
    10. Step-by-step derivation
      1. unpow20.3%

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

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{-0.5 \cdot \left(\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}\right)} \]
      3. associate-*r*0.3%

        \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{\left(-0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)}} \]
    11. Simplified0.3%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{\left(-0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)}} \]
    12. Taylor expanded in a around 0 18.8%

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

    if -2 < (*.f64 a x)

    1. Initial program 56.5%

      \[e^{a \cdot x} - 1 \]
    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 72.2%

      \[\leadsto \color{blue}{a \cdot x} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification56.7%

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

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 69.1%

    \[e^{a \cdot x} - 1 \]
  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 58.2%

    \[\leadsto \color{blue}{0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right) + a \cdot x} \]
  5. Step-by-step derivation
    1. +-commutative58.2%

      \[\leadsto \color{blue}{a \cdot x + 0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)} \]
    2. associate-*r*58.2%

      \[\leadsto a \cdot x + \color{blue}{\left(0.5 \cdot {a}^{2}\right) \cdot {x}^{2}} \]
    3. unpow258.2%

      \[\leadsto a \cdot x + \left(0.5 \cdot {a}^{2}\right) \cdot \color{blue}{\left(x \cdot x\right)} \]
    4. associate-*r*60.7%

      \[\leadsto a \cdot x + \color{blue}{\left(\left(0.5 \cdot {a}^{2}\right) \cdot x\right) \cdot x} \]
    5. distribute-rgt-out60.7%

      \[\leadsto \color{blue}{x \cdot \left(a + \left(0.5 \cdot {a}^{2}\right) \cdot x\right)} \]
    6. *-commutative60.7%

      \[\leadsto x \cdot \left(a + \color{blue}{x \cdot \left(0.5 \cdot {a}^{2}\right)}\right) \]
    7. *-commutative60.7%

      \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left({a}^{2} \cdot 0.5\right)}\right) \]
    8. unpow260.7%

      \[\leadsto x \cdot \left(a + x \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot 0.5\right)\right) \]
    9. associate-*l*60.7%

      \[\leadsto x \cdot \left(a + x \cdot \color{blue}{\left(a \cdot \left(a \cdot 0.5\right)\right)}\right) \]
  6. Simplified60.7%

    \[\leadsto \color{blue}{x \cdot \left(a + x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
  7. Step-by-step derivation
    1. distribute-lft-in60.7%

      \[\leadsto \color{blue}{x \cdot a + x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    2. flip-+20.6%

      \[\leadsto \color{blue}{\frac{\left(x \cdot a\right) \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)}} \]
    3. *-commutative20.6%

      \[\leadsto \frac{\color{blue}{\left(a \cdot x\right)} \cdot \left(x \cdot a\right) - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    4. *-commutative20.6%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \color{blue}{\left(a \cdot x\right)} - \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    5. *-commutative20.6%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    6. associate-*l*20.6%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right) \cdot \left(x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    7. *-commutative20.6%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    8. associate-*l*20.8%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}\right)}{x \cdot a - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    9. *-commutative20.8%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{a \cdot x} - x \cdot \left(x \cdot \left(a \cdot \left(a \cdot 0.5\right)\right)\right)} \]
    10. *-commutative20.8%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(\left(a \cdot \left(a \cdot 0.5\right)\right) \cdot x\right)}} \]
    11. associate-*l*26.4%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \color{blue}{\left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
  8. Applied egg-rr26.4%

    \[\leadsto \color{blue}{\frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{a \cdot x - x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)}} \]
  9. Taylor expanded in a around inf 2.1%

    \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{-0.5 \cdot \left({a}^{2} \cdot {x}^{2}\right)}} \]
  10. Step-by-step derivation
    1. unpow22.1%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{-0.5 \cdot \left(\color{blue}{\left(a \cdot a\right)} \cdot {x}^{2}\right)} \]
    2. unpow22.1%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{-0.5 \cdot \left(\left(a \cdot a\right) \cdot \color{blue}{\left(x \cdot x\right)}\right)} \]
    3. associate-*r*2.1%

      \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{\left(-0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)}} \]
  11. Simplified2.1%

    \[\leadsto \frac{\left(a \cdot x\right) \cdot \left(a \cdot x\right) - \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right) \cdot \left(x \cdot \left(a \cdot \left(\left(a \cdot 0.5\right) \cdot x\right)\right)\right)}{\color{blue}{\left(-0.5 \cdot \left(a \cdot a\right)\right) \cdot \left(x \cdot x\right)}} \]
  12. Taylor expanded in a around 0 7.3%

    \[\leadsto \color{blue}{-2} \]
  13. Final simplification7.3%

    \[\leadsto -2 \]

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 2023173 
(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))