Kahan's exp quotient

Percentage Accurate: 53.1% → 100.0%
Time: 10.2s
Alternatives: 13
Speedup: 8.8×

Specification

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

\\
\frac{e^{x} - 1}{x}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

The average percentage accuracy by input value. Horizontal axis shows value of an input variable; the variable is choosen in the title. Vertical axis is accuracy; higher is better. Red represent the original program, while blue represents Herbie's suggestion. These can be toggled with buttons below the plot. The line is an average while dots represent individual samples.

Accuracy vs Speed?

Herbie found 13 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: 53.1% accurate, 1.0× speedup?

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

\\
\frac{e^{x} - 1}{x}
\end{array}

Alternative 1: 100.0% accurate, 1.0× speedup?

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

\\
\frac{\mathsf{expm1}\left(x\right)}{x}
\end{array}
Derivation
  1. Initial program 45.1%

    \[\frac{e^{x} - 1}{x} \]
  2. Add Preprocessing
  3. Step-by-step derivation
    1. lower-expm1.f64100.0

      \[\leadsto \frac{\color{blue}{\mathsf{expm1}\left(x\right)}}{x} \]
  4. Applied egg-rr100.0%

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

Alternative 2: 70.1% accurate, 0.8× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{e^{x} + -1}{x} \leq 2:\\ \;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{-0.027777777777777776}{\mathsf{fma}\left(x, 0.041666666666666664, -0.16666666666666666\right)}, 0.5\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.041666666666666664 \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)}{x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= (/ (+ (exp x) -1.0) x) 2.0)
   (fma
    x
    (fma
     x
     (/
      -0.027777777777777776
      (fma x 0.041666666666666664 -0.16666666666666666))
     0.5)
    1.0)
   (/ (* 0.041666666666666664 (* x (* x (* x x)))) x)))
double code(double x) {
	double tmp;
	if (((exp(x) + -1.0) / x) <= 2.0) {
		tmp = fma(x, fma(x, (-0.027777777777777776 / fma(x, 0.041666666666666664, -0.16666666666666666)), 0.5), 1.0);
	} else {
		tmp = (0.041666666666666664 * (x * (x * (x * x)))) / x;
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (Float64(Float64(exp(x) + -1.0) / x) <= 2.0)
		tmp = fma(x, fma(x, Float64(-0.027777777777777776 / fma(x, 0.041666666666666664, -0.16666666666666666)), 0.5), 1.0);
	else
		tmp = Float64(Float64(0.041666666666666664 * Float64(x * Float64(x * Float64(x * x)))) / x);
	end
	return tmp
end
code[x_] := If[LessEqual[N[(N[(N[Exp[x], $MachinePrecision] + -1.0), $MachinePrecision] / x), $MachinePrecision], 2.0], N[(x * N[(x * N[(-0.027777777777777776 / N[(x * 0.041666666666666664 + -0.16666666666666666), $MachinePrecision]), $MachinePrecision] + 0.5), $MachinePrecision] + 1.0), $MachinePrecision], N[(N[(0.041666666666666664 * N[(x * N[(x * N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{e^{x} + -1}{x} \leq 2:\\
\;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{-0.027777777777777776}{\mathsf{fma}\left(x, 0.041666666666666664, -0.16666666666666666\right)}, 0.5\right), 1\right)\\

\mathbf{else}:\\
\;\;\;\;\frac{0.041666666666666664 \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)}{x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 (exp.f64 x) #s(literal 1 binary64)) x) < 2

    1. Initial program 29.3%

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

      \[\leadsto \color{blue}{1 + x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \color{blue}{x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right) + 1} \]
      2. lower-fma.f64N/A

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

        \[\leadsto \mathsf{fma}\left(x, \color{blue}{x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right) + \frac{1}{2}}, 1\right) \]
      4. lower-fma.f64N/A

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

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

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{24}} + \frac{1}{6}, \frac{1}{2}\right), 1\right) \]
      7. lower-fma.f6474.6

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right)}, 0.5\right), 1\right) \]
    5. Simplified74.6%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), 1\right)} \]
    6. Step-by-step derivation
      1. flip-+N/A

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\frac{\left(x \cdot \frac{1}{24}\right) \cdot \left(x \cdot \frac{1}{24}\right) - \frac{1}{6} \cdot \frac{1}{6}}{x \cdot \frac{1}{24} - \frac{1}{6}}}, \frac{1}{2}\right), 1\right) \]
      2. lower-/.f64N/A

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\frac{\left(x \cdot \frac{1}{24}\right) \cdot \left(x \cdot \frac{1}{24}\right) - \frac{1}{6} \cdot \frac{1}{6}}{x \cdot \frac{1}{24} - \frac{1}{6}}}, \frac{1}{2}\right), 1\right) \]
      3. sub-negN/A

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{\color{blue}{\left(x \cdot \frac{1}{24}\right) \cdot \left(x \cdot \frac{1}{24}\right) + \left(\mathsf{neg}\left(\frac{1}{6} \cdot \frac{1}{6}\right)\right)}}{x \cdot \frac{1}{24} - \frac{1}{6}}, \frac{1}{2}\right), 1\right) \]
      4. swap-sqrN/A

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{\color{blue}{\left(x \cdot x\right) \cdot \left(\frac{1}{24} \cdot \frac{1}{24}\right)} + \left(\mathsf{neg}\left(\frac{1}{6} \cdot \frac{1}{6}\right)\right)}{x \cdot \frac{1}{24} - \frac{1}{6}}, \frac{1}{2}\right), 1\right) \]
      5. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{\color{blue}{\mathsf{fma}\left(x \cdot x, \frac{1}{24} \cdot \frac{1}{24}, \mathsf{neg}\left(\frac{1}{6} \cdot \frac{1}{6}\right)\right)}}{x \cdot \frac{1}{24} - \frac{1}{6}}, \frac{1}{2}\right), 1\right) \]
      6. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{\mathsf{fma}\left(\color{blue}{x \cdot x}, \frac{1}{24} \cdot \frac{1}{24}, \mathsf{neg}\left(\frac{1}{6} \cdot \frac{1}{6}\right)\right)}{x \cdot \frac{1}{24} - \frac{1}{6}}, \frac{1}{2}\right), 1\right) \]
      7. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{\mathsf{fma}\left(x \cdot x, \color{blue}{\frac{1}{576}}, \mathsf{neg}\left(\frac{1}{6} \cdot \frac{1}{6}\right)\right)}{x \cdot \frac{1}{24} - \frac{1}{6}}, \frac{1}{2}\right), 1\right) \]
      8. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{\mathsf{fma}\left(x \cdot x, \frac{1}{576}, \mathsf{neg}\left(\color{blue}{\frac{1}{36}}\right)\right)}{x \cdot \frac{1}{24} - \frac{1}{6}}, \frac{1}{2}\right), 1\right) \]
      9. metadata-evalN/A

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{\mathsf{fma}\left(x \cdot x, \frac{1}{576}, \color{blue}{\frac{-1}{36}}\right)}{x \cdot \frac{1}{24} - \frac{1}{6}}, \frac{1}{2}\right), 1\right) \]
      10. sub-negN/A

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{\mathsf{fma}\left(x \cdot x, \frac{1}{576}, \frac{-1}{36}\right)}{\color{blue}{x \cdot \frac{1}{24} + \left(\mathsf{neg}\left(\frac{1}{6}\right)\right)}}, \frac{1}{2}\right), 1\right) \]
      11. lower-fma.f64N/A

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{\mathsf{fma}\left(x \cdot x, \frac{1}{576}, \frac{-1}{36}\right)}{\color{blue}{\mathsf{fma}\left(x, \frac{1}{24}, \mathsf{neg}\left(\frac{1}{6}\right)\right)}}, \frac{1}{2}\right), 1\right) \]
      12. metadata-eval74.6

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{\mathsf{fma}\left(x \cdot x, 0.001736111111111111, -0.027777777777777776\right)}{\mathsf{fma}\left(x, 0.041666666666666664, \color{blue}{-0.16666666666666666}\right)}, 0.5\right), 1\right) \]
    7. Applied egg-rr74.6%

      \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\frac{\mathsf{fma}\left(x \cdot x, 0.001736111111111111, -0.027777777777777776\right)}{\mathsf{fma}\left(x, 0.041666666666666664, -0.16666666666666666\right)}}, 0.5\right), 1\right) \]
    8. Taylor expanded in x around 0

      \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{\color{blue}{\frac{-1}{36}}}{\mathsf{fma}\left(x, \frac{1}{24}, \frac{-1}{6}\right)}, \frac{1}{2}\right), 1\right) \]
    9. Step-by-step derivation
      1. Simplified75.2%

        \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{\color{blue}{-0.027777777777777776}}{\mathsf{fma}\left(x, 0.041666666666666664, -0.16666666666666666\right)}, 0.5\right), 1\right) \]

      if 2 < (/.f64 (-.f64 (exp.f64 x) #s(literal 1 binary64)) x)

      1. Initial program 100.0%

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

        \[\leadsto \frac{\color{blue}{x \cdot \left(1 + x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right)}}{x} \]
      4. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \frac{x \cdot \color{blue}{\left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right) + 1\right)}}{x} \]
        2. distribute-lft-inN/A

          \[\leadsto \frac{\color{blue}{x \cdot \left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right) + x \cdot 1}}{x} \]
        3. *-rgt-identityN/A

          \[\leadsto \frac{x \cdot \left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right) + \color{blue}{x}}{x} \]
        4. lower-fma.f64N/A

          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right), x\right)}}{x} \]
        5. lower-*.f64N/A

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

          \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \color{blue}{\left(x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right) + \frac{1}{2}\right)}, x\right)}{x} \]
        7. lower-fma.f64N/A

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

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

          \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{24}} + \frac{1}{6}, \frac{1}{2}\right), x\right)}{x} \]
        10. lower-fma.f6479.8

          \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right)}, 0.5\right), x\right)}{x} \]
      5. Simplified79.8%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), x\right)}}{x} \]
      6. Taylor expanded in x around inf

        \[\leadsto \frac{\color{blue}{\frac{1}{24} \cdot {x}^{4}}}{x} \]
      7. Step-by-step derivation
        1. lower-*.f64N/A

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

          \[\leadsto \frac{\frac{1}{24} \cdot {x}^{\color{blue}{\left(3 + 1\right)}}}{x} \]
        3. pow-plusN/A

          \[\leadsto \frac{\frac{1}{24} \cdot \color{blue}{\left({x}^{3} \cdot x\right)}}{x} \]
        4. lower-*.f64N/A

          \[\leadsto \frac{\frac{1}{24} \cdot \color{blue}{\left({x}^{3} \cdot x\right)}}{x} \]
        5. cube-multN/A

          \[\leadsto \frac{\frac{1}{24} \cdot \left(\color{blue}{\left(x \cdot \left(x \cdot x\right)\right)} \cdot x\right)}{x} \]
        6. unpow2N/A

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

          \[\leadsto \frac{\frac{1}{24} \cdot \left(\color{blue}{\left(x \cdot {x}^{2}\right)} \cdot x\right)}{x} \]
        8. unpow2N/A

          \[\leadsto \frac{\frac{1}{24} \cdot \left(\left(x \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot x\right)}{x} \]
        9. lower-*.f6479.8

          \[\leadsto \frac{0.041666666666666664 \cdot \left(\left(x \cdot \color{blue}{\left(x \cdot x\right)}\right) \cdot x\right)}{x} \]
      8. Simplified79.8%

        \[\leadsto \frac{\color{blue}{0.041666666666666664 \cdot \left(\left(x \cdot \left(x \cdot x\right)\right) \cdot x\right)}}{x} \]
    10. Recombined 2 regimes into one program.
    11. Final simplification76.3%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{e^{x} + -1}{x} \leq 2:\\ \;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{-0.027777777777777776}{\mathsf{fma}\left(x, 0.041666666666666664, -0.16666666666666666\right)}, 0.5\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;\frac{0.041666666666666664 \cdot \left(x \cdot \left(x \cdot \left(x \cdot x\right)\right)\right)}{x}\\ \end{array} \]
    12. Add Preprocessing

    Alternative 3: 68.2% accurate, 0.8× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{e^{x} + -1}{x} \leq 2:\\ \;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.16666666666666666, 0.5\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\left(x \cdot x\right) \cdot 0.041666666666666664\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= (/ (+ (exp x) -1.0) x) 2.0)
       (fma x (fma x 0.16666666666666666 0.5) 1.0)
       (* x (* (* x x) 0.041666666666666664))))
    double code(double x) {
    	double tmp;
    	if (((exp(x) + -1.0) / x) <= 2.0) {
    		tmp = fma(x, fma(x, 0.16666666666666666, 0.5), 1.0);
    	} else {
    		tmp = x * ((x * x) * 0.041666666666666664);
    	}
    	return tmp;
    }
    
    function code(x)
    	tmp = 0.0
    	if (Float64(Float64(exp(x) + -1.0) / x) <= 2.0)
    		tmp = fma(x, fma(x, 0.16666666666666666, 0.5), 1.0);
    	else
    		tmp = Float64(x * Float64(Float64(x * x) * 0.041666666666666664));
    	end
    	return tmp
    end
    
    code[x_] := If[LessEqual[N[(N[(N[Exp[x], $MachinePrecision] + -1.0), $MachinePrecision] / x), $MachinePrecision], 2.0], N[(x * N[(x * 0.16666666666666666 + 0.5), $MachinePrecision] + 1.0), $MachinePrecision], N[(x * N[(N[(x * x), $MachinePrecision] * 0.041666666666666664), $MachinePrecision]), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;\frac{e^{x} + -1}{x} \leq 2:\\
    \;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.16666666666666666, 0.5\right), 1\right)\\
    
    \mathbf{else}:\\
    \;\;\;\;x \cdot \left(\left(x \cdot x\right) \cdot 0.041666666666666664\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (/.f64 (-.f64 (exp.f64 x) #s(literal 1 binary64)) x) < 2

      1. Initial program 29.3%

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{6}} + \frac{1}{2}, 1\right) \]
        5. lower-fma.f6475.0

          \[\leadsto \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.16666666666666666, 0.5\right)}, 1\right) \]
      5. Simplified75.0%

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.16666666666666666, 0.5\right), 1\right)} \]

      if 2 < (/.f64 (-.f64 (exp.f64 x) #s(literal 1 binary64)) x)

      1. Initial program 100.0%

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

        \[\leadsto \frac{\color{blue}{x \cdot \left(1 + x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right)}}{x} \]
      4. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \frac{x \cdot \color{blue}{\left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right) + 1\right)}}{x} \]
        2. distribute-lft-inN/A

          \[\leadsto \frac{\color{blue}{x \cdot \left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right) + x \cdot 1}}{x} \]
        3. *-rgt-identityN/A

          \[\leadsto \frac{x \cdot \left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right) + \color{blue}{x}}{x} \]
        4. lower-fma.f64N/A

          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right), x\right)}}{x} \]
        5. lower-*.f64N/A

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

          \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \color{blue}{\left(x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right) + \frac{1}{2}\right)}, x\right)}{x} \]
        7. lower-fma.f64N/A

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

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

          \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{24}} + \frac{1}{6}, \frac{1}{2}\right), x\right)}{x} \]
        10. lower-fma.f6479.8

          \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right)}, 0.5\right), x\right)}{x} \]
      5. Simplified79.8%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), x\right)}}{x} \]
      6. Step-by-step derivation
        1. lift-fma.f64N/A

          \[\leadsto \frac{x \cdot \left(x \cdot \left(x \cdot \color{blue}{\mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right)} + \frac{1}{2}\right)\right) + x}{x} \]
        2. lift-fma.f64N/A

          \[\leadsto \frac{x \cdot \left(x \cdot \color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right), \frac{1}{2}\right)}\right) + x}{x} \]
        3. lift-*.f64N/A

          \[\leadsto \frac{x \cdot \color{blue}{\left(x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right), \frac{1}{2}\right)\right)} + x}{x} \]
        4. lift-fma.f64N/A

          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right), \frac{1}{2}\right), x\right)}}{x} \]
        5. lift-/.f6479.8

          \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), x\right)}{x}} \]
        6. lift-fma.f64N/A

          \[\leadsto \frac{\color{blue}{x \cdot \left(x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right), \frac{1}{2}\right)\right) + x}}{x} \]
        7. lift-*.f64N/A

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

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

          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right), \frac{1}{2}\right) \cdot \left(x \cdot x\right)} + x}{x} \]
        10. lower-fma.f64N/A

          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right), \frac{1}{2}\right), x \cdot x, x\right)}}{x} \]
        11. lower-*.f6479.8

          \[\leadsto \frac{\mathsf{fma}\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), \color{blue}{x \cdot x}, x\right)}{x} \]
      7. Applied egg-rr79.8%

        \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), x \cdot x, x\right)}{x}} \]
      8. Taylor expanded in x around inf

        \[\leadsto \color{blue}{\frac{1}{24} \cdot {x}^{3}} \]
      9. Step-by-step derivation
        1. unpow3N/A

          \[\leadsto \frac{1}{24} \cdot \color{blue}{\left(\left(x \cdot x\right) \cdot x\right)} \]
        2. unpow2N/A

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

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

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

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

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

          \[\leadsto x \cdot \left(\frac{1}{24} \cdot \color{blue}{\left(x \cdot x\right)}\right) \]
        8. lower-*.f6473.4

          \[\leadsto x \cdot \left(0.041666666666666664 \cdot \color{blue}{\left(x \cdot x\right)}\right) \]
      10. Simplified73.4%

        \[\leadsto \color{blue}{x \cdot \left(0.041666666666666664 \cdot \left(x \cdot x\right)\right)} \]
    3. Recombined 2 regimes into one program.
    4. Final simplification74.6%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{e^{x} + -1}{x} \leq 2:\\ \;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.16666666666666666, 0.5\right), 1\right)\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(\left(x \cdot x\right) \cdot 0.041666666666666664\right)\\ \end{array} \]
    5. Add Preprocessing

    Alternative 4: 71.6% accurate, 1.6× speedup?

    \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(\left(x \cdot x\right) \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right) \cdot \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), -0.25\right), \frac{1}{\mathsf{fma}\left(x, 0.16666666666666666, -0.5\right)}, x\right)}{x} \end{array} \]
    (FPCore (x)
     :precision binary64
     (/
      (fma
       (*
        (* x x)
        (fma
         (* x x)
         (*
          (fma x 0.041666666666666664 0.16666666666666666)
          (fma x 0.041666666666666664 0.16666666666666666))
         -0.25))
       (/ 1.0 (fma x 0.16666666666666666 -0.5))
       x)
      x))
    double code(double x) {
    	return fma(((x * x) * fma((x * x), (fma(x, 0.041666666666666664, 0.16666666666666666) * fma(x, 0.041666666666666664, 0.16666666666666666)), -0.25)), (1.0 / fma(x, 0.16666666666666666, -0.5)), x) / x;
    }
    
    function code(x)
    	return Float64(fma(Float64(Float64(x * x) * fma(Float64(x * x), Float64(fma(x, 0.041666666666666664, 0.16666666666666666) * fma(x, 0.041666666666666664, 0.16666666666666666)), -0.25)), Float64(1.0 / fma(x, 0.16666666666666666, -0.5)), x) / x)
    end
    
    code[x_] := N[(N[(N[(N[(x * x), $MachinePrecision] * N[(N[(x * x), $MachinePrecision] * N[(N[(x * 0.041666666666666664 + 0.16666666666666666), $MachinePrecision] * N[(x * 0.041666666666666664 + 0.16666666666666666), $MachinePrecision]), $MachinePrecision] + -0.25), $MachinePrecision]), $MachinePrecision] * N[(1.0 / N[(x * 0.16666666666666666 + -0.5), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision] / x), $MachinePrecision]
    
    \begin{array}{l}
    
    \\
    \frac{\mathsf{fma}\left(\left(x \cdot x\right) \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right) \cdot \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), -0.25\right), \frac{1}{\mathsf{fma}\left(x, 0.16666666666666666, -0.5\right)}, x\right)}{x}
    \end{array}
    
    Derivation
    1. Initial program 45.1%

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

      \[\leadsto \frac{\color{blue}{x \cdot \left(1 + x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right)}}{x} \]
    4. Step-by-step derivation
      1. +-commutativeN/A

        \[\leadsto \frac{x \cdot \color{blue}{\left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right) + 1\right)}}{x} \]
      2. distribute-lft-inN/A

        \[\leadsto \frac{\color{blue}{x \cdot \left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right) + x \cdot 1}}{x} \]
      3. *-rgt-identityN/A

        \[\leadsto \frac{x \cdot \left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right) + \color{blue}{x}}{x} \]
      4. lower-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right), x\right)}}{x} \]
      5. lower-*.f64N/A

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

        \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \color{blue}{\left(x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right) + \frac{1}{2}\right)}, x\right)}{x} \]
      7. lower-fma.f64N/A

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

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

        \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{24}} + \frac{1}{6}, \frac{1}{2}\right), x\right)}{x} \]
      10. lower-fma.f6475.8

        \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right)}, 0.5\right), x\right)}{x} \]
    5. Simplified75.8%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), x\right)}}{x} \]
    6. Applied egg-rr66.6%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\left(x \cdot x\right) \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right) \cdot \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), -0.25\right), \frac{1}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), -0.5\right)}, x\right)}}{x} \]
    7. Taylor expanded in x around 0

      \[\leadsto \frac{\mathsf{fma}\left(\left(x \cdot x\right) \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right) \cdot \mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right), \frac{-1}{4}\right), \frac{1}{\mathsf{fma}\left(x, \color{blue}{\frac{1}{6}}, \frac{-1}{2}\right)}, x\right)}{x} \]
    8. Step-by-step derivation
      1. Simplified77.5%

        \[\leadsto \frac{\mathsf{fma}\left(\left(x \cdot x\right) \cdot \mathsf{fma}\left(x \cdot x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right) \cdot \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), -0.25\right), \frac{1}{\mathsf{fma}\left(x, \color{blue}{0.16666666666666666}, -0.5\right)}, x\right)}{x} \]
      2. Add Preprocessing

      Alternative 5: 69.4% accurate, 3.3× speedup?

      \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), x\right)}{x} \end{array} \]
      (FPCore (x)
       :precision binary64
       (/
        (fma x (* x (fma x (fma x 0.041666666666666664 0.16666666666666666) 0.5)) x)
        x))
      double code(double x) {
      	return fma(x, (x * fma(x, fma(x, 0.041666666666666664, 0.16666666666666666), 0.5)), x) / x;
      }
      
      function code(x)
      	return Float64(fma(x, Float64(x * fma(x, fma(x, 0.041666666666666664, 0.16666666666666666), 0.5)), x) / x)
      end
      
      code[x_] := N[(N[(x * N[(x * N[(x * N[(x * 0.041666666666666664 + 0.16666666666666666), $MachinePrecision] + 0.5), $MachinePrecision]), $MachinePrecision] + x), $MachinePrecision] / x), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \frac{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), x\right)}{x}
      \end{array}
      
      Derivation
      1. Initial program 45.1%

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

        \[\leadsto \frac{\color{blue}{x \cdot \left(1 + x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right)}}{x} \]
      4. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \frac{x \cdot \color{blue}{\left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right) + 1\right)}}{x} \]
        2. distribute-lft-inN/A

          \[\leadsto \frac{\color{blue}{x \cdot \left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right) + x \cdot 1}}{x} \]
        3. *-rgt-identityN/A

          \[\leadsto \frac{x \cdot \left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right) + \color{blue}{x}}{x} \]
        4. lower-fma.f64N/A

          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right), x\right)}}{x} \]
        5. lower-*.f64N/A

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

          \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \color{blue}{\left(x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right) + \frac{1}{2}\right)}, x\right)}{x} \]
        7. lower-fma.f64N/A

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

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

          \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{24}} + \frac{1}{6}, \frac{1}{2}\right), x\right)}{x} \]
        10. lower-fma.f6475.8

          \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right)}, 0.5\right), x\right)}{x} \]
      5. Simplified75.8%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), x\right)}}{x} \]
      6. Add Preprocessing

      Alternative 6: 68.6% accurate, 3.5× speedup?

      \[\begin{array}{l} \\ \frac{\mathsf{fma}\left(\left(x \cdot x\right) \cdot 0.041666666666666664, x \cdot x, x\right)}{x} \end{array} \]
      (FPCore (x)
       :precision binary64
       (/ (fma (* (* x x) 0.041666666666666664) (* x x) x) x))
      double code(double x) {
      	return fma(((x * x) * 0.041666666666666664), (x * x), x) / x;
      }
      
      function code(x)
      	return Float64(fma(Float64(Float64(x * x) * 0.041666666666666664), Float64(x * x), x) / x)
      end
      
      code[x_] := N[(N[(N[(N[(x * x), $MachinePrecision] * 0.041666666666666664), $MachinePrecision] * N[(x * x), $MachinePrecision] + x), $MachinePrecision] / x), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \frac{\mathsf{fma}\left(\left(x \cdot x\right) \cdot 0.041666666666666664, x \cdot x, x\right)}{x}
      \end{array}
      
      Derivation
      1. Initial program 45.1%

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

        \[\leadsto \frac{\color{blue}{x \cdot \left(1 + x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right)}}{x} \]
      4. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \frac{x \cdot \color{blue}{\left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right) + 1\right)}}{x} \]
        2. distribute-lft-inN/A

          \[\leadsto \frac{\color{blue}{x \cdot \left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right) + x \cdot 1}}{x} \]
        3. *-rgt-identityN/A

          \[\leadsto \frac{x \cdot \left(x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)\right) + \color{blue}{x}}{x} \]
        4. lower-fma.f64N/A

          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right), x\right)}}{x} \]
        5. lower-*.f64N/A

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

          \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \color{blue}{\left(x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right) + \frac{1}{2}\right)}, x\right)}{x} \]
        7. lower-fma.f64N/A

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

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

          \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{24}} + \frac{1}{6}, \frac{1}{2}\right), x\right)}{x} \]
        10. lower-fma.f6475.8

          \[\leadsto \frac{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right)}, 0.5\right), x\right)}{x} \]
      5. Simplified75.8%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), x\right)}}{x} \]
      6. Step-by-step derivation
        1. lift-fma.f64N/A

          \[\leadsto \frac{x \cdot \left(x \cdot \left(x \cdot \color{blue}{\mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right)} + \frac{1}{2}\right)\right) + x}{x} \]
        2. lift-fma.f64N/A

          \[\leadsto \frac{x \cdot \left(x \cdot \color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right), \frac{1}{2}\right)}\right) + x}{x} \]
        3. lift-*.f64N/A

          \[\leadsto \frac{x \cdot \color{blue}{\left(x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right), \frac{1}{2}\right)\right)} + x}{x} \]
        4. lift-fma.f64N/A

          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right), \frac{1}{2}\right), x\right)}}{x} \]
        5. lift-/.f6475.8

          \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x, x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), x\right)}{x}} \]
        6. lift-fma.f64N/A

          \[\leadsto \frac{\color{blue}{x \cdot \left(x \cdot \mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right), \frac{1}{2}\right)\right) + x}}{x} \]
        7. lift-*.f64N/A

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

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

          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right), \frac{1}{2}\right) \cdot \left(x \cdot x\right)} + x}{x} \]
        10. lower-fma.f64N/A

          \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, \frac{1}{24}, \frac{1}{6}\right), \frac{1}{2}\right), x \cdot x, x\right)}}{x} \]
        11. lower-*.f6475.8

          \[\leadsto \frac{\mathsf{fma}\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), \color{blue}{x \cdot x}, x\right)}{x} \]
      7. Applied egg-rr75.8%

        \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), x \cdot x, x\right)}{x}} \]
      8. Taylor expanded in x around inf

        \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{\frac{1}{24} \cdot {x}^{2}}, x \cdot x, x\right)}{x} \]
      9. Step-by-step derivation
        1. lower-*.f64N/A

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

          \[\leadsto \frac{\mathsf{fma}\left(\frac{1}{24} \cdot \color{blue}{\left(x \cdot x\right)}, x \cdot x, x\right)}{x} \]
        3. lower-*.f6475.2

          \[\leadsto \frac{\mathsf{fma}\left(0.041666666666666664 \cdot \color{blue}{\left(x \cdot x\right)}, x \cdot x, x\right)}{x} \]
      10. Simplified75.2%

        \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{0.041666666666666664 \cdot \left(x \cdot x\right)}, x \cdot x, x\right)}{x} \]
      11. Final simplification75.2%

        \[\leadsto \frac{\mathsf{fma}\left(\left(x \cdot x\right) \cdot 0.041666666666666664, x \cdot x, x\right)}{x} \]
      12. Add Preprocessing

      Alternative 7: 67.8% accurate, 6.1× speedup?

      \[\begin{array}{l} \\ \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), 1\right) \end{array} \]
      (FPCore (x)
       :precision binary64
       (fma x (fma x (fma x 0.041666666666666664 0.16666666666666666) 0.5) 1.0))
      double code(double x) {
      	return fma(x, fma(x, fma(x, 0.041666666666666664, 0.16666666666666666), 0.5), 1.0);
      }
      
      function code(x)
      	return fma(x, fma(x, fma(x, 0.041666666666666664, 0.16666666666666666), 0.5), 1.0)
      end
      
      code[x_] := N[(x * N[(x * N[(x * 0.041666666666666664 + 0.16666666666666666), $MachinePrecision] + 0.5), $MachinePrecision] + 1.0), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), 1\right)
      \end{array}
      
      Derivation
      1. Initial program 45.1%

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

        \[\leadsto \color{blue}{1 + x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right)} \]
      4. Step-by-step derivation
        1. +-commutativeN/A

          \[\leadsto \color{blue}{x \cdot \left(\frac{1}{2} + x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right)\right) + 1} \]
        2. lower-fma.f64N/A

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

          \[\leadsto \mathsf{fma}\left(x, \color{blue}{x \cdot \left(\frac{1}{6} + \frac{1}{24} \cdot x\right) + \frac{1}{2}}, 1\right) \]
        4. lower-fma.f64N/A

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

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

          \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{24}} + \frac{1}{6}, \frac{1}{2}\right), 1\right) \]
        7. lower-fma.f6474.4

          \[\leadsto \mathsf{fma}\left(x, \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right)}, 0.5\right), 1\right) \]
      5. Simplified74.4%

        \[\leadsto \color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.041666666666666664, 0.16666666666666666\right), 0.5\right), 1\right)} \]
      6. Add Preprocessing

      Alternative 8: 64.0% accurate, 6.4× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 1.4:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;x \cdot \mathsf{fma}\left(x, 0.16666666666666666, 0.5\right)\\ \end{array} \end{array} \]
      (FPCore (x)
       :precision binary64
       (if (<= x 1.4) 1.0 (* x (fma x 0.16666666666666666 0.5))))
      double code(double x) {
      	double tmp;
      	if (x <= 1.4) {
      		tmp = 1.0;
      	} else {
      		tmp = x * fma(x, 0.16666666666666666, 0.5);
      	}
      	return tmp;
      }
      
      function code(x)
      	tmp = 0.0
      	if (x <= 1.4)
      		tmp = 1.0;
      	else
      		tmp = Float64(x * fma(x, 0.16666666666666666, 0.5));
      	end
      	return tmp
      end
      
      code[x_] := If[LessEqual[x, 1.4], 1.0, N[(x * N[(x * 0.16666666666666666 + 0.5), $MachinePrecision]), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;x \leq 1.4:\\
      \;\;\;\;1\\
      
      \mathbf{else}:\\
      \;\;\;\;x \cdot \mathsf{fma}\left(x, 0.16666666666666666, 0.5\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if x < 1.3999999999999999

        1. Initial program 29.3%

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

          \[\leadsto \color{blue}{1} \]
        4. Step-by-step derivation
          1. Simplified74.9%

            \[\leadsto \color{blue}{1} \]

          if 1.3999999999999999 < x

          1. Initial program 100.0%

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

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

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

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

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

              \[\leadsto \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{6}} + \frac{1}{2}, 1\right) \]
            5. lower-fma.f6450.3

              \[\leadsto \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.16666666666666666, 0.5\right)}, 1\right) \]
          5. Simplified50.3%

            \[\leadsto \color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.16666666666666666, 0.5\right), 1\right)} \]
          6. Taylor expanded in x around inf

            \[\leadsto \color{blue}{{x}^{2} \cdot \left(\frac{1}{6} + \frac{1}{2} \cdot \frac{1}{x}\right)} \]
          7. Step-by-step derivation
            1. unpow2N/A

              \[\leadsto \color{blue}{\left(x \cdot x\right)} \cdot \left(\frac{1}{6} + \frac{1}{2} \cdot \frac{1}{x}\right) \]
            2. associate-*l*N/A

              \[\leadsto \color{blue}{x \cdot \left(x \cdot \left(\frac{1}{6} + \frac{1}{2} \cdot \frac{1}{x}\right)\right)} \]
            3. +-commutativeN/A

              \[\leadsto x \cdot \left(x \cdot \color{blue}{\left(\frac{1}{2} \cdot \frac{1}{x} + \frac{1}{6}\right)}\right) \]
            4. distribute-rgt-inN/A

              \[\leadsto x \cdot \color{blue}{\left(\left(\frac{1}{2} \cdot \frac{1}{x}\right) \cdot x + \frac{1}{6} \cdot x\right)} \]
            5. associate-*l*N/A

              \[\leadsto x \cdot \left(\color{blue}{\frac{1}{2} \cdot \left(\frac{1}{x} \cdot x\right)} + \frac{1}{6} \cdot x\right) \]
            6. lft-mult-inverseN/A

              \[\leadsto x \cdot \left(\frac{1}{2} \cdot \color{blue}{1} + \frac{1}{6} \cdot x\right) \]
            7. metadata-evalN/A

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

              \[\leadsto \color{blue}{x \cdot \left(\frac{1}{2} + \frac{1}{6} \cdot x\right)} \]
            9. +-commutativeN/A

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

              \[\leadsto x \cdot \left(\color{blue}{x \cdot \frac{1}{6}} + \frac{1}{2}\right) \]
            11. lower-fma.f6450.3

              \[\leadsto x \cdot \color{blue}{\mathsf{fma}\left(x, 0.16666666666666666, 0.5\right)} \]
          8. Simplified50.3%

            \[\leadsto \color{blue}{x \cdot \mathsf{fma}\left(x, 0.16666666666666666, 0.5\right)} \]
        5. Recombined 2 regimes into one program.
        6. Add Preprocessing

        Alternative 9: 64.0% accurate, 6.8× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq 2.5:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;x \cdot \left(x \cdot 0.16666666666666666\right)\\ \end{array} \end{array} \]
        (FPCore (x)
         :precision binary64
         (if (<= x 2.5) 1.0 (* x (* x 0.16666666666666666))))
        double code(double x) {
        	double tmp;
        	if (x <= 2.5) {
        		tmp = 1.0;
        	} else {
        		tmp = x * (x * 0.16666666666666666);
        	}
        	return tmp;
        }
        
        real(8) function code(x)
            real(8), intent (in) :: x
            real(8) :: tmp
            if (x <= 2.5d0) then
                tmp = 1.0d0
            else
                tmp = x * (x * 0.16666666666666666d0)
            end if
            code = tmp
        end function
        
        public static double code(double x) {
        	double tmp;
        	if (x <= 2.5) {
        		tmp = 1.0;
        	} else {
        		tmp = x * (x * 0.16666666666666666);
        	}
        	return tmp;
        }
        
        def code(x):
        	tmp = 0
        	if x <= 2.5:
        		tmp = 1.0
        	else:
        		tmp = x * (x * 0.16666666666666666)
        	return tmp
        
        function code(x)
        	tmp = 0.0
        	if (x <= 2.5)
        		tmp = 1.0;
        	else
        		tmp = Float64(x * Float64(x * 0.16666666666666666));
        	end
        	return tmp
        end
        
        function tmp_2 = code(x)
        	tmp = 0.0;
        	if (x <= 2.5)
        		tmp = 1.0;
        	else
        		tmp = x * (x * 0.16666666666666666);
        	end
        	tmp_2 = tmp;
        end
        
        code[x_] := If[LessEqual[x, 2.5], 1.0, N[(x * N[(x * 0.16666666666666666), $MachinePrecision]), $MachinePrecision]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;x \leq 2.5:\\
        \;\;\;\;1\\
        
        \mathbf{else}:\\
        \;\;\;\;x \cdot \left(x \cdot 0.16666666666666666\right)\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if x < 2.5

          1. Initial program 29.3%

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

            \[\leadsto \color{blue}{1} \]
          4. Step-by-step derivation
            1. Simplified74.9%

              \[\leadsto \color{blue}{1} \]

            if 2.5 < x

            1. Initial program 100.0%

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

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

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

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

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

                \[\leadsto \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{6}} + \frac{1}{2}, 1\right) \]
              5. lower-fma.f6450.3

                \[\leadsto \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.16666666666666666, 0.5\right)}, 1\right) \]
            5. Simplified50.3%

              \[\leadsto \color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.16666666666666666, 0.5\right), 1\right)} \]
            6. Taylor expanded in x around inf

              \[\leadsto \color{blue}{\frac{1}{6} \cdot {x}^{2}} \]
            7. Step-by-step derivation
              1. unpow2N/A

                \[\leadsto \frac{1}{6} \cdot \color{blue}{\left(x \cdot x\right)} \]
              2. associate-*r*N/A

                \[\leadsto \color{blue}{\left(\frac{1}{6} \cdot x\right) \cdot x} \]
              3. *-commutativeN/A

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

                \[\leadsto \color{blue}{x \cdot \left(\frac{1}{6} \cdot x\right)} \]
              5. *-commutativeN/A

                \[\leadsto x \cdot \color{blue}{\left(x \cdot \frac{1}{6}\right)} \]
              6. lower-*.f6450.3

                \[\leadsto x \cdot \color{blue}{\left(x \cdot 0.16666666666666666\right)} \]
            8. Simplified50.3%

              \[\leadsto \color{blue}{x \cdot \left(x \cdot 0.16666666666666666\right)} \]
          5. Recombined 2 regimes into one program.
          6. Add Preprocessing

          Alternative 10: 64.2% accurate, 8.8× speedup?

          \[\begin{array}{l} \\ \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.16666666666666666, 0.5\right), 1\right) \end{array} \]
          (FPCore (x) :precision binary64 (fma x (fma x 0.16666666666666666 0.5) 1.0))
          double code(double x) {
          	return fma(x, fma(x, 0.16666666666666666, 0.5), 1.0);
          }
          
          function code(x)
          	return fma(x, fma(x, 0.16666666666666666, 0.5), 1.0)
          end
          
          code[x_] := N[(x * N[(x * 0.16666666666666666 + 0.5), $MachinePrecision] + 1.0), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.16666666666666666, 0.5\right), 1\right)
          \end{array}
          
          Derivation
          1. Initial program 45.1%

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

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

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

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

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

              \[\leadsto \mathsf{fma}\left(x, \color{blue}{x \cdot \frac{1}{6}} + \frac{1}{2}, 1\right) \]
            5. lower-fma.f6469.5

              \[\leadsto \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(x, 0.16666666666666666, 0.5\right)}, 1\right) \]
          5. Simplified69.5%

            \[\leadsto \color{blue}{\mathsf{fma}\left(x, \mathsf{fma}\left(x, 0.16666666666666666, 0.5\right), 1\right)} \]
          6. Add Preprocessing

          Alternative 11: 51.4% accurate, 16.4× speedup?

          \[\begin{array}{l} \\ \mathsf{fma}\left(x, 0.5, 1\right) \end{array} \]
          (FPCore (x) :precision binary64 (fma x 0.5 1.0))
          double code(double x) {
          	return fma(x, 0.5, 1.0);
          }
          
          function code(x)
          	return fma(x, 0.5, 1.0)
          end
          
          code[x_] := N[(x * 0.5 + 1.0), $MachinePrecision]
          
          \begin{array}{l}
          
          \\
          \mathsf{fma}\left(x, 0.5, 1\right)
          \end{array}
          
          Derivation
          1. Initial program 45.1%

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

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

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

              \[\leadsto \color{blue}{x \cdot \frac{1}{2}} + 1 \]
            3. lower-fma.f6459.2

              \[\leadsto \color{blue}{\mathsf{fma}\left(x, 0.5, 1\right)} \]
          5. Simplified59.2%

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

          Alternative 12: 51.1% accurate, 115.0× speedup?

          \[\begin{array}{l} \\ 1 \end{array} \]
          (FPCore (x) :precision binary64 1.0)
          double code(double x) {
          	return 1.0;
          }
          
          real(8) function code(x)
              real(8), intent (in) :: x
              code = 1.0d0
          end function
          
          public static double code(double x) {
          	return 1.0;
          }
          
          def code(x):
          	return 1.0
          
          function code(x)
          	return 1.0
          end
          
          function tmp = code(x)
          	tmp = 1.0;
          end
          
          code[x_] := 1.0
          
          \begin{array}{l}
          
          \\
          1
          \end{array}
          
          Derivation
          1. Initial program 45.1%

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

            \[\leadsto \color{blue}{1} \]
          4. Step-by-step derivation
            1. Simplified58.9%

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

            Alternative 13: 3.3% accurate, 115.0× speedup?

            \[\begin{array}{l} \\ 0 \end{array} \]
            (FPCore (x) :precision binary64 0.0)
            double code(double x) {
            	return 0.0;
            }
            
            real(8) function code(x)
                real(8), intent (in) :: x
                code = 0.0d0
            end function
            
            public static double code(double x) {
            	return 0.0;
            }
            
            def code(x):
            	return 0.0
            
            function code(x)
            	return 0.0
            end
            
            function tmp = code(x)
            	tmp = 0.0;
            end
            
            code[x_] := 0.0
            
            \begin{array}{l}
            
            \\
            0
            \end{array}
            
            Derivation
            1. Initial program 45.1%

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

              \[\leadsto \frac{\color{blue}{1} - 1}{x} \]
            4. Step-by-step derivation
              1. Simplified3.3%

                \[\leadsto \frac{\color{blue}{1} - 1}{x} \]
              2. Step-by-step derivation
                1. metadata-evalN/A

                  \[\leadsto \frac{\color{blue}{0}}{x} \]
                2. div03.3

                  \[\leadsto \color{blue}{0} \]
              3. Applied egg-rr3.3%

                \[\leadsto \color{blue}{0} \]
              4. Add Preprocessing

              Developer Target 1: 52.7% accurate, 0.4× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} t_0 := e^{x} - 1\\ \mathbf{if}\;x < 1 \land x > -1:\\ \;\;\;\;\frac{t\_0}{\log \left(e^{x}\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{t\_0}{x}\\ \end{array} \end{array} \]
              (FPCore (x)
               :precision binary64
               (let* ((t_0 (- (exp x) 1.0)))
                 (if (and (< x 1.0) (> x -1.0)) (/ t_0 (log (exp x))) (/ t_0 x))))
              double code(double x) {
              	double t_0 = exp(x) - 1.0;
              	double tmp;
              	if ((x < 1.0) && (x > -1.0)) {
              		tmp = t_0 / log(exp(x));
              	} else {
              		tmp = t_0 / x;
              	}
              	return tmp;
              }
              
              real(8) function code(x)
                  real(8), intent (in) :: x
                  real(8) :: t_0
                  real(8) :: tmp
                  t_0 = exp(x) - 1.0d0
                  if ((x < 1.0d0) .and. (x > (-1.0d0))) then
                      tmp = t_0 / log(exp(x))
                  else
                      tmp = t_0 / x
                  end if
                  code = tmp
              end function
              
              public static double code(double x) {
              	double t_0 = Math.exp(x) - 1.0;
              	double tmp;
              	if ((x < 1.0) && (x > -1.0)) {
              		tmp = t_0 / Math.log(Math.exp(x));
              	} else {
              		tmp = t_0 / x;
              	}
              	return tmp;
              }
              
              def code(x):
              	t_0 = math.exp(x) - 1.0
              	tmp = 0
              	if (x < 1.0) and (x > -1.0):
              		tmp = t_0 / math.log(math.exp(x))
              	else:
              		tmp = t_0 / x
              	return tmp
              
              function code(x)
              	t_0 = Float64(exp(x) - 1.0)
              	tmp = 0.0
              	if ((x < 1.0) && (x > -1.0))
              		tmp = Float64(t_0 / log(exp(x)));
              	else
              		tmp = Float64(t_0 / x);
              	end
              	return tmp
              end
              
              function tmp_2 = code(x)
              	t_0 = exp(x) - 1.0;
              	tmp = 0.0;
              	if ((x < 1.0) && (x > -1.0))
              		tmp = t_0 / log(exp(x));
              	else
              		tmp = t_0 / x;
              	end
              	tmp_2 = tmp;
              end
              
              code[x_] := Block[{t$95$0 = N[(N[Exp[x], $MachinePrecision] - 1.0), $MachinePrecision]}, If[And[Less[x, 1.0], Greater[x, -1.0]], N[(t$95$0 / N[Log[N[Exp[x], $MachinePrecision]], $MachinePrecision]), $MachinePrecision], N[(t$95$0 / x), $MachinePrecision]]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              t_0 := e^{x} - 1\\
              \mathbf{if}\;x < 1 \land x > -1:\\
              \;\;\;\;\frac{t\_0}{\log \left(e^{x}\right)}\\
              
              \mathbf{else}:\\
              \;\;\;\;\frac{t\_0}{x}\\
              
              
              \end{array}
              \end{array}
              

              Reproduce

              ?
              herbie shell --seed 2024208 
              (FPCore (x)
                :name "Kahan's exp quotient"
                :precision binary64
              
                :alt
                (! :herbie-platform default (if (and (< x 1) (> x -1)) (/ (- (exp x) 1) (log (exp x))) (/ (- (exp x) 1) x)))
              
                (/ (- (exp x) 1.0) x))