expax (section 3.5)

Percentage Accurate: 55.2% → 100.0%
Time: 9.4s
Alternatives: 7
Speedup: 18.2×

Specification

?
\[710 > a \cdot x\]
\[\begin{array}{l} \\ e^{a \cdot x} - 1 \end{array} \]
(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 7 alternatives:

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

Initial Program: 55.2% 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 48.9%

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

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

      \[\leadsto \color{blue}{e^{a \cdot x}} - 1 \]
    3. lower-expm1.f64100.0

      \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
  4. Applied rewrites100.0%

    \[\leadsto \color{blue}{\mathsf{expm1}\left(a \cdot x\right)} \]
  5. Add Preprocessing

Alternative 2: 70.6% accurate, 2.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot x \leq -2 \cdot 10^{+101}:\\ \;\;\;\;\frac{1}{-0.5}\\ \mathbf{elif}\;a \cdot x \leq -4 \cdot 10^{+18}:\\ \;\;\;\;a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right)\right) + -1\\ \mathbf{else}:\\ \;\;\;\;a \cdot \mathsf{fma}\left(x \cdot \left(a \cdot 0.5\right), x, x\right)\\ \end{array} \end{array} \]
(FPCore (a x)
 :precision binary64
 (if (<= (* a x) -2e+101)
   (/ 1.0 -0.5)
   (if (<= (* a x) -4e+18)
     (+ (* a (* a (* x (* x 0.5)))) -1.0)
     (* a (fma (* x (* a 0.5)) x x)))))
double code(double a, double x) {
	double tmp;
	if ((a * x) <= -2e+101) {
		tmp = 1.0 / -0.5;
	} else if ((a * x) <= -4e+18) {
		tmp = (a * (a * (x * (x * 0.5)))) + -1.0;
	} else {
		tmp = a * fma((x * (a * 0.5)), x, x);
	}
	return tmp;
}
function code(a, x)
	tmp = 0.0
	if (Float64(a * x) <= -2e+101)
		tmp = Float64(1.0 / -0.5);
	elseif (Float64(a * x) <= -4e+18)
		tmp = Float64(Float64(a * Float64(a * Float64(x * Float64(x * 0.5)))) + -1.0);
	else
		tmp = Float64(a * fma(Float64(x * Float64(a * 0.5)), x, x));
	end
	return tmp
end
code[a_, x_] := If[LessEqual[N[(a * x), $MachinePrecision], -2e+101], N[(1.0 / -0.5), $MachinePrecision], If[LessEqual[N[(a * x), $MachinePrecision], -4e+18], N[(N[(a * N[(a * N[(x * N[(x * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision], N[(a * N[(N[(x * N[(a * 0.5), $MachinePrecision]), $MachinePrecision] * x + x), $MachinePrecision]), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;a \cdot x \leq -2 \cdot 10^{+101}:\\
\;\;\;\;\frac{1}{-0.5}\\

\mathbf{elif}\;a \cdot x \leq -4 \cdot 10^{+18}:\\
\;\;\;\;a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right)\right) + -1\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 a x) < -2e101

    1. Initial program 100.0%

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

        \[\leadsto \color{blue}{e^{a \cdot x} - 1} \]
      2. flip3--N/A

        \[\leadsto \color{blue}{\frac{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}} \]
      3. clear-numN/A

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

        \[\leadsto \color{blue}{\frac{1}{\frac{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}}} \]
      5. clear-numN/A

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}}}} \]
      6. flip3--N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
      7. lift--.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
      8. lower-/.f64100.0

        \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a \cdot x} - 1}}} \]
      9. lift--.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
      10. lift-exp.f64N/A

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x}} - 1}} \]
      11. lower-expm1.f64100.0

        \[\leadsto \frac{1}{\frac{1}{\color{blue}{\mathsf{expm1}\left(a \cdot x\right)}}} \]
    4. Applied rewrites100.0%

      \[\leadsto \color{blue}{\frac{1}{\frac{1}{\mathsf{expm1}\left(a \cdot x\right)}}} \]
    5. Taylor expanded in x around 0

      \[\leadsto \frac{1}{\color{blue}{\frac{\frac{-1}{2} \cdot x + \frac{1}{a}}{x}}} \]
    6. Step-by-step derivation
      1. lower-/.f64N/A

        \[\leadsto \frac{1}{\color{blue}{\frac{\frac{-1}{2} \cdot x + \frac{1}{a}}{x}}} \]
      2. *-commutativeN/A

        \[\leadsto \frac{1}{\frac{\color{blue}{x \cdot \frac{-1}{2}} + \frac{1}{a}}{x}} \]
      3. lower-fma.f64N/A

        \[\leadsto \frac{1}{\frac{\color{blue}{\mathsf{fma}\left(x, \frac{-1}{2}, \frac{1}{a}\right)}}{x}} \]
      4. lower-/.f6418.8

        \[\leadsto \frac{1}{\frac{\mathsf{fma}\left(x, -0.5, \color{blue}{\frac{1}{a}}\right)}{x}} \]
    7. Applied rewrites18.8%

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

      \[\leadsto \frac{1}{\frac{-1}{2}} \]
    9. Step-by-step derivation
      1. Applied rewrites18.8%

        \[\leadsto \frac{1}{-0.5} \]

      if -2e101 < (*.f64 a x) < -4e18

      1. Initial program 100.0%

        \[e^{a \cdot x} - 1 \]
      2. Add Preprocessing
      3. Taylor expanded in a around 0

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

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(a, \mathsf{fma}\left(a, \frac{1}{2} \cdot \color{blue}{\left(x \cdot x\right)}, x\right), 1\right) - 1 \]
        10. lower-*.f642.0

          \[\leadsto \mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5 \cdot \color{blue}{\left(x \cdot x\right)}, x\right), 1\right) - 1 \]
      5. Applied rewrites2.0%

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

        \[\leadsto \frac{1}{2} \cdot \color{blue}{\left({a}^{2} \cdot {x}^{2}\right)} - 1 \]
      7. Step-by-step derivation
        1. Applied rewrites19.7%

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

        if -4e18 < (*.f64 a x)

        1. Initial program 29.4%

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

            \[\leadsto \color{blue}{e^{a \cdot x} - 1} \]
          2. flip3--N/A

            \[\leadsto \color{blue}{\frac{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}} \]
          3. clear-numN/A

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

            \[\leadsto \color{blue}{\frac{1}{\frac{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}}} \]
          5. clear-numN/A

            \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}}}} \]
          6. flip3--N/A

            \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
          7. lift--.f64N/A

            \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
          8. lower-/.f6429.4

            \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a \cdot x} - 1}}} \]
          9. lift--.f64N/A

            \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
          10. lift-exp.f64N/A

            \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x}} - 1}} \]
          11. lower-expm1.f6499.1

            \[\leadsto \frac{1}{\frac{1}{\color{blue}{\mathsf{expm1}\left(a \cdot x\right)}}} \]
        4. Applied rewrites99.1%

          \[\leadsto \color{blue}{\frac{1}{\frac{1}{\mathsf{expm1}\left(a \cdot x\right)}}} \]
        5. Taylor expanded in a around 0

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

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

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

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

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

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

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

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

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

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

            \[\leadsto a \cdot \mathsf{fma}\left(a, \frac{1}{2} \cdot \color{blue}{\left(x \cdot x\right)}, x\right) \]
          11. lower-*.f6492.9

            \[\leadsto a \cdot \mathsf{fma}\left(a, 0.5 \cdot \color{blue}{\left(x \cdot x\right)}, x\right) \]
        7. Applied rewrites92.9%

          \[\leadsto \color{blue}{a \cdot \mathsf{fma}\left(a, 0.5 \cdot \left(x \cdot x\right), x\right)} \]
        8. Step-by-step derivation
          1. Applied rewrites98.4%

            \[\leadsto a \cdot \mathsf{fma}\left(\left(a \cdot 0.5\right) \cdot x, \color{blue}{x}, x\right) \]
        9. Recombined 3 regimes into one program.
        10. Final simplification76.4%

          \[\leadsto \begin{array}{l} \mathbf{if}\;a \cdot x \leq -2 \cdot 10^{+101}:\\ \;\;\;\;\frac{1}{-0.5}\\ \mathbf{elif}\;a \cdot x \leq -4 \cdot 10^{+18}:\\ \;\;\;\;a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right)\right) + -1\\ \mathbf{else}:\\ \;\;\;\;a \cdot \mathsf{fma}\left(x \cdot \left(a \cdot 0.5\right), x, x\right)\\ \end{array} \]
        11. Add Preprocessing

        Alternative 3: 70.0% accurate, 2.9× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \leq -2.5 \cdot 10^{+237}:\\ \;\;\;\;a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right)\right) + -1\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{-0.5 + \frac{1}{a \cdot x}}\\ \end{array} \end{array} \]
        (FPCore (a x)
         :precision binary64
         (if (<= a -2.5e+237)
           (+ (* a (* a (* x (* x 0.5)))) -1.0)
           (/ 1.0 (+ -0.5 (/ 1.0 (* a x))))))
        double code(double a, double x) {
        	double tmp;
        	if (a <= -2.5e+237) {
        		tmp = (a * (a * (x * (x * 0.5)))) + -1.0;
        	} else {
        		tmp = 1.0 / (-0.5 + (1.0 / (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 <= (-2.5d+237)) then
                tmp = (a * (a * (x * (x * 0.5d0)))) + (-1.0d0)
            else
                tmp = 1.0d0 / ((-0.5d0) + (1.0d0 / (a * x)))
            end if
            code = tmp
        end function
        
        public static double code(double a, double x) {
        	double tmp;
        	if (a <= -2.5e+237) {
        		tmp = (a * (a * (x * (x * 0.5)))) + -1.0;
        	} else {
        		tmp = 1.0 / (-0.5 + (1.0 / (a * x)));
        	}
        	return tmp;
        }
        
        def code(a, x):
        	tmp = 0
        	if a <= -2.5e+237:
        		tmp = (a * (a * (x * (x * 0.5)))) + -1.0
        	else:
        		tmp = 1.0 / (-0.5 + (1.0 / (a * x)))
        	return tmp
        
        function code(a, x)
        	tmp = 0.0
        	if (a <= -2.5e+237)
        		tmp = Float64(Float64(a * Float64(a * Float64(x * Float64(x * 0.5)))) + -1.0);
        	else
        		tmp = Float64(1.0 / Float64(-0.5 + Float64(1.0 / Float64(a * x))));
        	end
        	return tmp
        end
        
        function tmp_2 = code(a, x)
        	tmp = 0.0;
        	if (a <= -2.5e+237)
        		tmp = (a * (a * (x * (x * 0.5)))) + -1.0;
        	else
        		tmp = 1.0 / (-0.5 + (1.0 / (a * x)));
        	end
        	tmp_2 = tmp;
        end
        
        code[a_, x_] := If[LessEqual[a, -2.5e+237], N[(N[(a * N[(a * N[(x * N[(x * 0.5), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision], N[(1.0 / N[(-0.5 + N[(1.0 / N[(a * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;a \leq -2.5 \cdot 10^{+237}:\\
        \;\;\;\;a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right)\right) + -1\\
        
        \mathbf{else}:\\
        \;\;\;\;\frac{1}{-0.5 + \frac{1}{a \cdot x}}\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if a < -2.5000000000000001e237

          1. Initial program 90.3%

            \[e^{a \cdot x} - 1 \]
          2. Add Preprocessing
          3. Taylor expanded in a around 0

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

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

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

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

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

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

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

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

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

              \[\leadsto \mathsf{fma}\left(a, \mathsf{fma}\left(a, \frac{1}{2} \cdot \color{blue}{\left(x \cdot x\right)}, x\right), 1\right) - 1 \]
            10. lower-*.f645.8

              \[\leadsto \mathsf{fma}\left(a, \mathsf{fma}\left(a, 0.5 \cdot \color{blue}{\left(x \cdot x\right)}, x\right), 1\right) - 1 \]
          5. Applied rewrites5.8%

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

            \[\leadsto \frac{1}{2} \cdot \color{blue}{\left({a}^{2} \cdot {x}^{2}\right)} - 1 \]
          7. Step-by-step derivation
            1. Applied rewrites42.8%

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

            if -2.5000000000000001e237 < a

            1. Initial program 47.3%

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

                \[\leadsto \color{blue}{e^{a \cdot x} - 1} \]
              2. flip3--N/A

                \[\leadsto \color{blue}{\frac{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}} \]
              3. clear-numN/A

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

                \[\leadsto \color{blue}{\frac{1}{\frac{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}}} \]
              5. clear-numN/A

                \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}}}} \]
              6. flip3--N/A

                \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
              7. lift--.f64N/A

                \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
              8. lower-/.f6447.3

                \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a \cdot x} - 1}}} \]
              9. lift--.f64N/A

                \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
              10. lift-exp.f64N/A

                \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x}} - 1}} \]
              11. lower-expm1.f6499.3

                \[\leadsto \frac{1}{\frac{1}{\color{blue}{\mathsf{expm1}\left(a \cdot x\right)}}} \]
            4. Applied rewrites99.3%

              \[\leadsto \color{blue}{\frac{1}{\frac{1}{\mathsf{expm1}\left(a \cdot x\right)}}} \]
            5. Taylor expanded in x around 0

              \[\leadsto \frac{1}{\color{blue}{\frac{\frac{-1}{2} \cdot x + \frac{1}{a}}{x}}} \]
            6. Step-by-step derivation
              1. lower-/.f64N/A

                \[\leadsto \frac{1}{\color{blue}{\frac{\frac{-1}{2} \cdot x + \frac{1}{a}}{x}}} \]
              2. *-commutativeN/A

                \[\leadsto \frac{1}{\frac{\color{blue}{x \cdot \frac{-1}{2}} + \frac{1}{a}}{x}} \]
              3. lower-fma.f64N/A

                \[\leadsto \frac{1}{\frac{\color{blue}{\mathsf{fma}\left(x, \frac{-1}{2}, \frac{1}{a}\right)}}{x}} \]
              4. lower-/.f6477.4

                \[\leadsto \frac{1}{\frac{\mathsf{fma}\left(x, -0.5, \color{blue}{\frac{1}{a}}\right)}{x}} \]
            7. Applied rewrites77.4%

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

              \[\leadsto \frac{1}{\frac{1}{a \cdot x} - \color{blue}{\frac{1}{2}}} \]
            9. Step-by-step derivation
              1. Applied rewrites77.6%

                \[\leadsto \frac{1}{\frac{1}{a \cdot x} + \color{blue}{-0.5}} \]
            10. Recombined 2 regimes into one program.
            11. Final simplification76.3%

              \[\leadsto \begin{array}{l} \mathbf{if}\;a \leq -2.5 \cdot 10^{+237}:\\ \;\;\;\;a \cdot \left(a \cdot \left(x \cdot \left(x \cdot 0.5\right)\right)\right) + -1\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{-0.5 + \frac{1}{a \cdot x}}\\ \end{array} \]
            12. Add Preprocessing

            Alternative 4: 70.7% accurate, 3.3× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot x \leq -4 \cdot 10^{+18}:\\ \;\;\;\;\frac{1}{-0.5}\\ \mathbf{else}:\\ \;\;\;\;a \cdot \mathsf{fma}\left(x \cdot \left(a \cdot 0.5\right), x, x\right)\\ \end{array} \end{array} \]
            (FPCore (a x)
             :precision binary64
             (if (<= (* a x) -4e+18) (/ 1.0 -0.5) (* a (fma (* x (* a 0.5)) x x))))
            double code(double a, double x) {
            	double tmp;
            	if ((a * x) <= -4e+18) {
            		tmp = 1.0 / -0.5;
            	} else {
            		tmp = a * fma((x * (a * 0.5)), x, x);
            	}
            	return tmp;
            }
            
            function code(a, x)
            	tmp = 0.0
            	if (Float64(a * x) <= -4e+18)
            		tmp = Float64(1.0 / -0.5);
            	else
            		tmp = Float64(a * fma(Float64(x * Float64(a * 0.5)), x, x));
            	end
            	return tmp
            end
            
            code[a_, x_] := If[LessEqual[N[(a * x), $MachinePrecision], -4e+18], N[(1.0 / -0.5), $MachinePrecision], N[(a * N[(N[(x * N[(a * 0.5), $MachinePrecision]), $MachinePrecision] * x + x), $MachinePrecision]), $MachinePrecision]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            \mathbf{if}\;a \cdot x \leq -4 \cdot 10^{+18}:\\
            \;\;\;\;\frac{1}{-0.5}\\
            
            \mathbf{else}:\\
            \;\;\;\;a \cdot \mathsf{fma}\left(x \cdot \left(a \cdot 0.5\right), x, x\right)\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 2 regimes
            2. if (*.f64 a x) < -4e18

              1. Initial program 100.0%

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

                  \[\leadsto \color{blue}{e^{a \cdot x} - 1} \]
                2. flip3--N/A

                  \[\leadsto \color{blue}{\frac{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}} \]
                3. clear-numN/A

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

                  \[\leadsto \color{blue}{\frac{1}{\frac{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}}} \]
                5. clear-numN/A

                  \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}}}} \]
                6. flip3--N/A

                  \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
                7. lift--.f64N/A

                  \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
                8. lower-/.f64100.0

                  \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a \cdot x} - 1}}} \]
                9. lift--.f64N/A

                  \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
                10. lift-exp.f64N/A

                  \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x}} - 1}} \]
                11. lower-expm1.f64100.0

                  \[\leadsto \frac{1}{\frac{1}{\color{blue}{\mathsf{expm1}\left(a \cdot x\right)}}} \]
              4. Applied rewrites100.0%

                \[\leadsto \color{blue}{\frac{1}{\frac{1}{\mathsf{expm1}\left(a \cdot x\right)}}} \]
              5. Taylor expanded in x around 0

                \[\leadsto \frac{1}{\color{blue}{\frac{\frac{-1}{2} \cdot x + \frac{1}{a}}{x}}} \]
              6. Step-by-step derivation
                1. lower-/.f64N/A

                  \[\leadsto \frac{1}{\color{blue}{\frac{\frac{-1}{2} \cdot x + \frac{1}{a}}{x}}} \]
                2. *-commutativeN/A

                  \[\leadsto \frac{1}{\frac{\color{blue}{x \cdot \frac{-1}{2}} + \frac{1}{a}}{x}} \]
                3. lower-fma.f64N/A

                  \[\leadsto \frac{1}{\frac{\color{blue}{\mathsf{fma}\left(x, \frac{-1}{2}, \frac{1}{a}\right)}}{x}} \]
                4. lower-/.f6418.8

                  \[\leadsto \frac{1}{\frac{\mathsf{fma}\left(x, -0.5, \color{blue}{\frac{1}{a}}\right)}{x}} \]
              7. Applied rewrites18.8%

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

                \[\leadsto \frac{1}{\frac{-1}{2}} \]
              9. Step-by-step derivation
                1. Applied rewrites18.8%

                  \[\leadsto \frac{1}{-0.5} \]

                if -4e18 < (*.f64 a x)

                1. Initial program 29.4%

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

                    \[\leadsto \color{blue}{e^{a \cdot x} - 1} \]
                  2. flip3--N/A

                    \[\leadsto \color{blue}{\frac{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}} \]
                  3. clear-numN/A

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

                    \[\leadsto \color{blue}{\frac{1}{\frac{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}}} \]
                  5. clear-numN/A

                    \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}}}} \]
                  6. flip3--N/A

                    \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
                  7. lift--.f64N/A

                    \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
                  8. lower-/.f6429.4

                    \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a \cdot x} - 1}}} \]
                  9. lift--.f64N/A

                    \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
                  10. lift-exp.f64N/A

                    \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x}} - 1}} \]
                  11. lower-expm1.f6499.1

                    \[\leadsto \frac{1}{\frac{1}{\color{blue}{\mathsf{expm1}\left(a \cdot x\right)}}} \]
                4. Applied rewrites99.1%

                  \[\leadsto \color{blue}{\frac{1}{\frac{1}{\mathsf{expm1}\left(a \cdot x\right)}}} \]
                5. Taylor expanded in a around 0

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

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

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

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

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

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

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

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

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

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

                    \[\leadsto a \cdot \mathsf{fma}\left(a, \frac{1}{2} \cdot \color{blue}{\left(x \cdot x\right)}, x\right) \]
                  11. lower-*.f6492.9

                    \[\leadsto a \cdot \mathsf{fma}\left(a, 0.5 \cdot \color{blue}{\left(x \cdot x\right)}, x\right) \]
                7. Applied rewrites92.9%

                  \[\leadsto \color{blue}{a \cdot \mathsf{fma}\left(a, 0.5 \cdot \left(x \cdot x\right), x\right)} \]
                8. Step-by-step derivation
                  1. Applied rewrites98.4%

                    \[\leadsto a \cdot \mathsf{fma}\left(\left(a \cdot 0.5\right) \cdot x, \color{blue}{x}, x\right) \]
                9. Recombined 2 regimes into one program.
                10. Final simplification76.3%

                  \[\leadsto \begin{array}{l} \mathbf{if}\;a \cdot x \leq -4 \cdot 10^{+18}:\\ \;\;\;\;\frac{1}{-0.5}\\ \mathbf{else}:\\ \;\;\;\;a \cdot \mathsf{fma}\left(x \cdot \left(a \cdot 0.5\right), x, x\right)\\ \end{array} \]
                11. Add Preprocessing

                Alternative 5: 70.2% accurate, 4.7× speedup?

                \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;a \cdot x \leq -4 \cdot 10^{+18}:\\ \;\;\;\;\frac{1}{-0.5}\\ \mathbf{else}:\\ \;\;\;\;a \cdot x\\ \end{array} \end{array} \]
                (FPCore (a x)
                 :precision binary64
                 (if (<= (* a x) -4e+18) (/ 1.0 -0.5) (* a x)))
                double code(double a, double x) {
                	double tmp;
                	if ((a * x) <= -4e+18) {
                		tmp = 1.0 / -0.5;
                	} 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) <= (-4d+18)) then
                        tmp = 1.0d0 / (-0.5d0)
                    else
                        tmp = a * x
                    end if
                    code = tmp
                end function
                
                public static double code(double a, double x) {
                	double tmp;
                	if ((a * x) <= -4e+18) {
                		tmp = 1.0 / -0.5;
                	} else {
                		tmp = a * x;
                	}
                	return tmp;
                }
                
                def code(a, x):
                	tmp = 0
                	if (a * x) <= -4e+18:
                		tmp = 1.0 / -0.5
                	else:
                		tmp = a * x
                	return tmp
                
                function code(a, x)
                	tmp = 0.0
                	if (Float64(a * x) <= -4e+18)
                		tmp = Float64(1.0 / -0.5);
                	else
                		tmp = Float64(a * x);
                	end
                	return tmp
                end
                
                function tmp_2 = code(a, x)
                	tmp = 0.0;
                	if ((a * x) <= -4e+18)
                		tmp = 1.0 / -0.5;
                	else
                		tmp = a * x;
                	end
                	tmp_2 = tmp;
                end
                
                code[a_, x_] := If[LessEqual[N[(a * x), $MachinePrecision], -4e+18], N[(1.0 / -0.5), $MachinePrecision], N[(a * x), $MachinePrecision]]
                
                \begin{array}{l}
                
                \\
                \begin{array}{l}
                \mathbf{if}\;a \cdot x \leq -4 \cdot 10^{+18}:\\
                \;\;\;\;\frac{1}{-0.5}\\
                
                \mathbf{else}:\\
                \;\;\;\;a \cdot x\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if (*.f64 a x) < -4e18

                  1. Initial program 100.0%

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

                      \[\leadsto \color{blue}{e^{a \cdot x} - 1} \]
                    2. flip3--N/A

                      \[\leadsto \color{blue}{\frac{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}} \]
                    3. clear-numN/A

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

                      \[\leadsto \color{blue}{\frac{1}{\frac{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}}} \]
                    5. clear-numN/A

                      \[\leadsto \frac{1}{\color{blue}{\frac{1}{\frac{{\left(e^{a \cdot x}\right)}^{3} - {1}^{3}}{e^{a \cdot x} \cdot e^{a \cdot x} + \left(1 \cdot 1 + e^{a \cdot x} \cdot 1\right)}}}} \]
                    6. flip3--N/A

                      \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
                    7. lift--.f64N/A

                      \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
                    8. lower-/.f64100.0

                      \[\leadsto \frac{1}{\color{blue}{\frac{1}{e^{a \cdot x} - 1}}} \]
                    9. lift--.f64N/A

                      \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x} - 1}}} \]
                    10. lift-exp.f64N/A

                      \[\leadsto \frac{1}{\frac{1}{\color{blue}{e^{a \cdot x}} - 1}} \]
                    11. lower-expm1.f64100.0

                      \[\leadsto \frac{1}{\frac{1}{\color{blue}{\mathsf{expm1}\left(a \cdot x\right)}}} \]
                  4. Applied rewrites100.0%

                    \[\leadsto \color{blue}{\frac{1}{\frac{1}{\mathsf{expm1}\left(a \cdot x\right)}}} \]
                  5. Taylor expanded in x around 0

                    \[\leadsto \frac{1}{\color{blue}{\frac{\frac{-1}{2} \cdot x + \frac{1}{a}}{x}}} \]
                  6. Step-by-step derivation
                    1. lower-/.f64N/A

                      \[\leadsto \frac{1}{\color{blue}{\frac{\frac{-1}{2} \cdot x + \frac{1}{a}}{x}}} \]
                    2. *-commutativeN/A

                      \[\leadsto \frac{1}{\frac{\color{blue}{x \cdot \frac{-1}{2}} + \frac{1}{a}}{x}} \]
                    3. lower-fma.f64N/A

                      \[\leadsto \frac{1}{\frac{\color{blue}{\mathsf{fma}\left(x, \frac{-1}{2}, \frac{1}{a}\right)}}{x}} \]
                    4. lower-/.f6418.8

                      \[\leadsto \frac{1}{\frac{\mathsf{fma}\left(x, -0.5, \color{blue}{\frac{1}{a}}\right)}{x}} \]
                  7. Applied rewrites18.8%

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

                    \[\leadsto \frac{1}{\frac{-1}{2}} \]
                  9. Step-by-step derivation
                    1. Applied rewrites18.8%

                      \[\leadsto \frac{1}{-0.5} \]

                    if -4e18 < (*.f64 a x)

                    1. Initial program 29.4%

                      \[e^{a \cdot x} - 1 \]
                    2. Add Preprocessing
                    3. Taylor expanded in a around 0

                      \[\leadsto \color{blue}{a \cdot x} \]
                    4. Step-by-step derivation
                      1. lower-*.f6497.7

                        \[\leadsto \color{blue}{a \cdot x} \]
                    5. Applied rewrites97.7%

                      \[\leadsto \color{blue}{a \cdot x} \]
                  10. Recombined 2 regimes into one program.
                  11. Add Preprocessing

                  Alternative 6: 65.7% accurate, 18.2× speedup?

                  \[\begin{array}{l} \\ a \cdot x \end{array} \]
                  (FPCore (a x) :precision binary64 (* a x))
                  double code(double a, double x) {
                  	return a * x;
                  }
                  
                  real(8) function code(a, x)
                      real(8), intent (in) :: a
                      real(8), intent (in) :: x
                      code = a * x
                  end function
                  
                  public static double code(double a, double x) {
                  	return a * x;
                  }
                  
                  def code(a, x):
                  	return a * x
                  
                  function code(a, x)
                  	return Float64(a * x)
                  end
                  
                  function tmp = code(a, x)
                  	tmp = a * x;
                  end
                  
                  code[a_, x_] := N[(a * x), $MachinePrecision]
                  
                  \begin{array}{l}
                  
                  \\
                  a \cdot x
                  \end{array}
                  
                  Derivation
                  1. Initial program 48.9%

                    \[e^{a \cdot x} - 1 \]
                  2. Add Preprocessing
                  3. Taylor expanded in a around 0

                    \[\leadsto \color{blue}{a \cdot x} \]
                  4. Step-by-step derivation
                    1. lower-*.f6471.9

                      \[\leadsto \color{blue}{a \cdot x} \]
                  5. Applied rewrites71.9%

                    \[\leadsto \color{blue}{a \cdot x} \]
                  6. Add Preprocessing

                  Alternative 7: 19.5% accurate, 27.3× speedup?

                  \[\begin{array}{l} \\ 1 + -1 \end{array} \]
                  (FPCore (a x) :precision binary64 (+ 1.0 -1.0))
                  double code(double a, double x) {
                  	return 1.0 + -1.0;
                  }
                  
                  real(8) function code(a, x)
                      real(8), intent (in) :: a
                      real(8), intent (in) :: x
                      code = 1.0d0 + (-1.0d0)
                  end function
                  
                  public static double code(double a, double x) {
                  	return 1.0 + -1.0;
                  }
                  
                  def code(a, x):
                  	return 1.0 + -1.0
                  
                  function code(a, x)
                  	return Float64(1.0 + -1.0)
                  end
                  
                  function tmp = code(a, x)
                  	tmp = 1.0 + -1.0;
                  end
                  
                  code[a_, x_] := N[(1.0 + -1.0), $MachinePrecision]
                  
                  \begin{array}{l}
                  
                  \\
                  1 + -1
                  \end{array}
                  
                  Derivation
                  1. Initial program 48.9%

                    \[e^{a \cdot x} - 1 \]
                  2. Add Preprocessing
                  3. Taylor expanded in a around 0

                    \[\leadsto \color{blue}{1} - 1 \]
                  4. Step-by-step derivation
                    1. Applied rewrites19.9%

                      \[\leadsto \color{blue}{1} - 1 \]
                    2. Final simplification19.9%

                      \[\leadsto 1 + -1 \]
                    3. Add Preprocessing

                    Developer Target 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}
                    

                    Reproduce

                    ?
                    herbie shell --seed 2024238 
                    (FPCore (a x)
                      :name "expax (section 3.5)"
                      :precision binary64
                      :pre (> 710.0 (* a x))
                    
                      :alt
                      (! :herbie-platform default (expm1 (* a x)))
                    
                      (- (exp (* a x)) 1.0))