expq2 (section 3.11)

Percentage Accurate: 37.6% → 100.0%
Time: 6.3s
Alternatives: 12
Speedup: 17.9×

Specification

?
\[710 > x\]
\[\begin{array}{l} \\ \frac{e^{x}}{e^{x} - 1} \end{array} \]
(FPCore (x) :precision binary64 (/ (exp x) (- (exp x) 1.0)))
double code(double x) {
	return exp(x) / (exp(x) - 1.0);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

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

\\
\frac{e^{x}}{e^{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 12 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: 37.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{e^{x}}{e^{x} - 1} \end{array} \]
(FPCore (x) :precision binary64 (/ (exp x) (- (exp x) 1.0)))
double code(double x) {
	return exp(x) / (exp(x) - 1.0);
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

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

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

Alternative 1: 100.0% accurate, 1.0× speedup?

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

\\
\frac{e^{x}}{\mathsf{expm1}\left(x\right)}
\end{array}
Derivation
  1. Initial program 35.5%

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

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

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

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

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

Alternative 2: 83.0% accurate, 1.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;e^{x} \leq 2 \cdot 10^{-6}:\\ \;\;\;\;\frac{1}{\left(0.5 \cdot x\right) \cdot x}\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(0.5, x, 1\right)}{x}\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (if (<= (exp x) 2e-6) (/ 1.0 (* (* 0.5 x) x)) (/ (fma 0.5 x 1.0) x)))
double code(double x) {
	double tmp;
	if (exp(x) <= 2e-6) {
		tmp = 1.0 / ((0.5 * x) * x);
	} else {
		tmp = fma(0.5, x, 1.0) / x;
	}
	return tmp;
}
function code(x)
	tmp = 0.0
	if (exp(x) <= 2e-6)
		tmp = Float64(1.0 / Float64(Float64(0.5 * x) * x));
	else
		tmp = Float64(fma(0.5, x, 1.0) / x);
	end
	return tmp
end
code[x_] := If[LessEqual[N[Exp[x], $MachinePrecision], 2e-6], N[(1.0 / N[(N[(0.5 * x), $MachinePrecision] * x), $MachinePrecision]), $MachinePrecision], N[(N[(0.5 * x + 1.0), $MachinePrecision] / x), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;e^{x} \leq 2 \cdot 10^{-6}:\\
\;\;\;\;\frac{1}{\left(0.5 \cdot x\right) \cdot x}\\

\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{fma}\left(0.5, x, 1\right)}{x}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (exp.f64 x) < 1.99999999999999991e-6

    1. Initial program 100.0%

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

      \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
    4. Step-by-step derivation
      1. Applied rewrites99.0%

        \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
      2. Taylor expanded in x around 0

        \[\leadsto \frac{\color{blue}{1}}{x} \]
      3. Step-by-step derivation
        1. Applied rewrites5.5%

          \[\leadsto \frac{\color{blue}{1}}{x} \]
        2. Taylor expanded in x around 0

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

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

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

            \[\leadsto \frac{1}{\left(\frac{1}{2} \cdot x + 1\right) \cdot x} \]
          4. lower-fma.f6447.3

            \[\leadsto \frac{1}{\mathsf{fma}\left(0.5, x, 1\right) \cdot x} \]
        4. Applied rewrites47.3%

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

          \[\leadsto \frac{1}{\left(\frac{1}{2} \cdot x\right) \cdot x} \]
        6. Step-by-step derivation
          1. lower-*.f6447.3

            \[\leadsto \frac{1}{\left(0.5 \cdot x\right) \cdot x} \]
        7. Applied rewrites47.3%

          \[\leadsto \frac{1}{\left(0.5 \cdot x\right) \cdot x} \]

        if 1.99999999999999991e-6 < (exp.f64 x)

        1. Initial program 5.6%

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

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

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

            \[\leadsto \frac{\frac{1}{2} \cdot x + 1}{x} \]
          3. lower-fma.f6498.9

            \[\leadsto \frac{\mathsf{fma}\left(0.5, x, 1\right)}{x} \]
        5. Applied rewrites98.9%

          \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(0.5, x, 1\right)}{x}} \]
      4. Recombined 2 regimes into one program.
      5. Add Preprocessing

      Alternative 3: 98.7% accurate, 1.7× speedup?

      \[\begin{array}{l} \\ \frac{e^{x}}{\mathsf{fma}\left(0.5, x, 1\right) \cdot x} \end{array} \]
      (FPCore (x) :precision binary64 (/ (exp x) (* (fma 0.5 x 1.0) x)))
      double code(double x) {
      	return exp(x) / (fma(0.5, x, 1.0) * x);
      }
      
      function code(x)
      	return Float64(exp(x) / Float64(fma(0.5, x, 1.0) * x))
      end
      
      code[x_] := N[(N[Exp[x], $MachinePrecision] / N[(N[(0.5 * x + 1.0), $MachinePrecision] * x), $MachinePrecision]), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \frac{e^{x}}{\mathsf{fma}\left(0.5, x, 1\right) \cdot x}
      \end{array}
      
      Derivation
      1. Initial program 35.5%

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

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

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

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

          \[\leadsto \frac{e^{x}}{\left(\frac{1}{2} \cdot x + 1\right) \cdot x} \]
        4. lower-fma.f6498.7

          \[\leadsto \frac{e^{x}}{\mathsf{fma}\left(0.5, x, 1\right) \cdot x} \]
      5. Applied rewrites98.7%

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

      Alternative 4: 98.1% accurate, 1.9× speedup?

      \[\begin{array}{l} \\ \frac{e^{x}}{x} \end{array} \]
      (FPCore (x) :precision binary64 (/ (exp x) x))
      double code(double x) {
      	return exp(x) / x;
      }
      
      module fmin_fmax_functions
          implicit none
          private
          public fmax
          public fmin
      
          interface fmax
              module procedure fmax88
              module procedure fmax44
              module procedure fmax84
              module procedure fmax48
          end interface
          interface fmin
              module procedure fmin88
              module procedure fmin44
              module procedure fmin84
              module procedure fmin48
          end interface
      contains
          real(8) function fmax88(x, y) result (res)
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              res = merge(y, merge(x, max(x, y), y /= y), x /= x)
          end function
          real(4) function fmax44(x, y) result (res)
              real(4), intent (in) :: x
              real(4), intent (in) :: y
              res = merge(y, merge(x, max(x, y), y /= y), x /= x)
          end function
          real(8) function fmax84(x, y) result(res)
              real(8), intent (in) :: x
              real(4), intent (in) :: y
              res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
          end function
          real(8) function fmax48(x, y) result(res)
              real(4), intent (in) :: x
              real(8), intent (in) :: y
              res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
          end function
          real(8) function fmin88(x, y) result (res)
              real(8), intent (in) :: x
              real(8), intent (in) :: y
              res = merge(y, merge(x, min(x, y), y /= y), x /= x)
          end function
          real(4) function fmin44(x, y) result (res)
              real(4), intent (in) :: x
              real(4), intent (in) :: y
              res = merge(y, merge(x, min(x, y), y /= y), x /= x)
          end function
          real(8) function fmin84(x, y) result(res)
              real(8), intent (in) :: x
              real(4), intent (in) :: y
              res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
          end function
          real(8) function fmin48(x, y) result(res)
              real(4), intent (in) :: x
              real(8), intent (in) :: y
              res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
          end function
      end module
      
      real(8) function code(x)
      use fmin_fmax_functions
          real(8), intent (in) :: x
          code = exp(x) / x
      end function
      
      public static double code(double x) {
      	return Math.exp(x) / x;
      }
      
      def code(x):
      	return math.exp(x) / x
      
      function code(x)
      	return Float64(exp(x) / x)
      end
      
      function tmp = code(x)
      	tmp = exp(x) / x;
      end
      
      code[x_] := N[(N[Exp[x], $MachinePrecision] / x), $MachinePrecision]
      
      \begin{array}{l}
      
      \\
      \frac{e^{x}}{x}
      \end{array}
      
      Derivation
      1. Initial program 35.5%

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

        \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
      4. Step-by-step derivation
        1. Applied rewrites98.3%

          \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
        2. Add Preprocessing

        Alternative 5: 93.8% accurate, 2.9× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \leq -2 \cdot 10^{+103}:\\ \;\;\;\;\frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, x, 0.5\right), x, 1\right) \cdot x}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{\frac{\left(\mathsf{vcubic}\left(0.041666666666666664, 0.16666666666666666, 0.5, -1, x\right) \cdot \mathsf{vcubic}\left(0.041666666666666664, 0.16666666666666666, 0.5, 1, x\right)\right) \cdot x}{\mathsf{vcubic}\left(0.041666666666666664, 0.16666666666666666, 0.5, -1, x\right)}}\\ \end{array} \end{array} \]
        (FPCore (x)
         :precision binary64
         (if (<= x -2e+103)
           (/ 1.0 (* (fma (fma 0.16666666666666666 x 0.5) x 1.0) x))
           (/
            1.0
            (/
             (*
              (*
               (vcubic 0.041666666666666664 0.16666666666666666 0.5 -1.0 x)
               (vcubic 0.041666666666666664 0.16666666666666666 0.5 1.0 x))
              x)
             (vcubic 0.041666666666666664 0.16666666666666666 0.5 -1.0 x)))))
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        \mathbf{if}\;x \leq -2 \cdot 10^{+103}:\\
        \;\;\;\;\frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, x, 0.5\right), x, 1\right) \cdot x}\\
        
        \mathbf{else}:\\
        \;\;\;\;\frac{1}{\frac{\left(\mathsf{vcubic}\left(0.041666666666666664, 0.16666666666666666, 0.5, -1, x\right) \cdot \mathsf{vcubic}\left(0.041666666666666664, 0.16666666666666666, 0.5, 1, x\right)\right) \cdot x}{\mathsf{vcubic}\left(0.041666666666666664, 0.16666666666666666, 0.5, -1, x\right)}}\\
        
        
        \end{array}
        \end{array}
        
        Derivation
        1. Split input into 2 regimes
        2. if x < -2e103

          1. Initial program 100.0%

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

            \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
          4. Step-by-step derivation
            1. Applied rewrites100.0%

              \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
            2. Taylor expanded in x around 0

              \[\leadsto \frac{\color{blue}{1}}{x} \]
            3. Step-by-step derivation
              1. Applied rewrites6.5%

                \[\leadsto \frac{\color{blue}{1}}{x} \]
              2. Taylor expanded in x around 0

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

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

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

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

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

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

                  \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{1}{6} \cdot x + \frac{1}{2}, x, 1\right) \cdot x} \]
                7. lower-fma.f64100.0

                  \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, x, 0.5\right), x, 1\right) \cdot x} \]
              4. Applied rewrites100.0%

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

              if -2e103 < x

              1. Initial program 20.2%

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

                \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
              4. Step-by-step derivation
                1. Applied rewrites97.9%

                  \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
                2. Taylor expanded in x around 0

                  \[\leadsto \frac{\color{blue}{1}}{x} \]
                3. Step-by-step derivation
                  1. Applied rewrites83.6%

                    \[\leadsto \frac{\color{blue}{1}}{x} \]
                  2. Taylor expanded in x around 0

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

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

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

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

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

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

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

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

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

                      \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{24} \cdot x + \frac{1}{6}, x, \frac{1}{2}\right), x, 1\right) \cdot x} \]
                    10. lower-fma.f6485.6

                      \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x, 0.16666666666666666\right), x, 0.5\right), x, 1\right) \cdot x} \]
                  4. Applied rewrites85.6%

                    \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x, 0.16666666666666666\right), x, 0.5\right), x, 1\right) \cdot x}} \]
                  5. Applied rewrites92.8%

                    \[\leadsto \frac{1}{\frac{\left(\mathsf{vcubic}\left(0.041666666666666664, 0.16666666666666666, 0.5, -1, x\right) \cdot \mathsf{vcubic}\left(0.041666666666666664, 0.16666666666666666, 0.5, 1, x\right)\right) \cdot x}{\color{blue}{\mathsf{vcubic}\left(0.041666666666666664, 0.16666666666666666, 0.5, -1, x\right)}}} \]
                4. Recombined 2 regimes into one program.
                5. Add Preprocessing

                Alternative 6: 90.6% accurate, 6.5× speedup?

                \[\begin{array}{l} \\ \frac{1}{\mathsf{fma}\left(\left(0.041666666666666664 \cdot x\right) \cdot x, x, 1\right) \cdot x} \end{array} \]
                (FPCore (x)
                 :precision binary64
                 (/ 1.0 (* (fma (* (* 0.041666666666666664 x) x) x 1.0) x)))
                double code(double x) {
                	return 1.0 / (fma(((0.041666666666666664 * x) * x), x, 1.0) * x);
                }
                
                function code(x)
                	return Float64(1.0 / Float64(fma(Float64(Float64(0.041666666666666664 * x) * x), x, 1.0) * x))
                end
                
                code[x_] := N[(1.0 / N[(N[(N[(N[(0.041666666666666664 * x), $MachinePrecision] * x), $MachinePrecision] * x + 1.0), $MachinePrecision] * x), $MachinePrecision]), $MachinePrecision]
                
                \begin{array}{l}
                
                \\
                \frac{1}{\mathsf{fma}\left(\left(0.041666666666666664 \cdot x\right) \cdot x, x, 1\right) \cdot x}
                \end{array}
                
                Derivation
                1. Initial program 35.5%

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

                  \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
                4. Step-by-step derivation
                  1. Applied rewrites98.3%

                    \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
                  2. Taylor expanded in x around 0

                    \[\leadsto \frac{\color{blue}{1}}{x} \]
                  3. Step-by-step derivation
                    1. Applied rewrites68.8%

                      \[\leadsto \frac{\color{blue}{1}}{x} \]
                    2. Taylor expanded in x around 0

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

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

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

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

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

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

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

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

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

                        \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{24} \cdot x + \frac{1}{6}, x, \frac{1}{2}\right), x, 1\right) \cdot x} \]
                      10. lower-fma.f6488.3

                        \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x, 0.16666666666666666\right), x, 0.5\right), x, 1\right) \cdot x} \]
                    4. Applied rewrites88.3%

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

                      \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{1}{24} \cdot {x}^{2}, x, 1\right) \cdot x} \]
                    6. Step-by-step derivation
                      1. unpow2N/A

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

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

                        \[\leadsto \frac{1}{\mathsf{fma}\left(\left(\frac{1}{24} \cdot x\right) \cdot x, x, 1\right) \cdot x} \]
                      4. lower-*.f6488.4

                        \[\leadsto \frac{1}{\mathsf{fma}\left(\left(0.041666666666666664 \cdot x\right) \cdot x, x, 1\right) \cdot x} \]
                    7. Applied rewrites88.4%

                      \[\leadsto \frac{1}{\mathsf{fma}\left(\left(0.041666666666666664 \cdot x\right) \cdot x, x, 1\right) \cdot x} \]
                    8. Add Preprocessing

                    Alternative 7: 90.5% accurate, 7.4× speedup?

                    \[\begin{array}{l} \\ \frac{1}{\mathsf{vcubic}\left(0.041666666666666664, 0.16666666666666666, 0.5, 1, x\right) \cdot x} \end{array} \]
                    (FPCore (x)
                     :precision binary64
                     (/ 1.0 (* (vcubic 0.041666666666666664 0.16666666666666666 0.5 1.0 x) x)))
                    \begin{array}{l}
                    
                    \\
                    \frac{1}{\mathsf{vcubic}\left(0.041666666666666664, 0.16666666666666666, 0.5, 1, x\right) \cdot x}
                    \end{array}
                    
                    Derivation
                    1. Initial program 35.5%

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

                      \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
                    4. Step-by-step derivation
                      1. Applied rewrites98.3%

                        \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
                      2. Taylor expanded in x around 0

                        \[\leadsto \frac{\color{blue}{1}}{x} \]
                      3. Step-by-step derivation
                        1. Applied rewrites68.8%

                          \[\leadsto \frac{\color{blue}{1}}{x} \]
                        2. Taylor expanded in x around 0

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

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

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

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

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

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

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

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

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

                            \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\frac{1}{24} \cdot x + \frac{1}{6}, x, \frac{1}{2}\right), x, 1\right) \cdot x} \]
                          10. lower-fma.f6488.3

                            \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x, 0.16666666666666666\right), x, 0.5\right), x, 1\right) \cdot x} \]
                        4. Applied rewrites88.3%

                          \[\leadsto \frac{1}{\color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(\mathsf{fma}\left(0.041666666666666664, x, 0.16666666666666666\right), x, 0.5\right), x, 1\right) \cdot x}} \]
                        5. Step-by-step derivation
                          1. Applied rewrites88.3%

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

                          Alternative 8: 87.8% accurate, 7.4× speedup?

                          \[\begin{array}{l} \\ \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, x, 0.5\right), x, 1\right) \cdot x} \end{array} \]
                          (FPCore (x)
                           :precision binary64
                           (/ 1.0 (* (fma (fma 0.16666666666666666 x 0.5) x 1.0) x)))
                          double code(double x) {
                          	return 1.0 / (fma(fma(0.16666666666666666, x, 0.5), x, 1.0) * x);
                          }
                          
                          function code(x)
                          	return Float64(1.0 / Float64(fma(fma(0.16666666666666666, x, 0.5), x, 1.0) * x))
                          end
                          
                          code[x_] := N[(1.0 / N[(N[(N[(0.16666666666666666 * x + 0.5), $MachinePrecision] * x + 1.0), $MachinePrecision] * x), $MachinePrecision]), $MachinePrecision]
                          
                          \begin{array}{l}
                          
                          \\
                          \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, x, 0.5\right), x, 1\right) \cdot x}
                          \end{array}
                          
                          Derivation
                          1. Initial program 35.5%

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

                            \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
                          4. Step-by-step derivation
                            1. Applied rewrites98.3%

                              \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
                            2. Taylor expanded in x around 0

                              \[\leadsto \frac{\color{blue}{1}}{x} \]
                            3. Step-by-step derivation
                              1. Applied rewrites68.8%

                                \[\leadsto \frac{\color{blue}{1}}{x} \]
                              2. Taylor expanded in x around 0

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

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

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

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

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

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

                                  \[\leadsto \frac{1}{\mathsf{fma}\left(\frac{1}{6} \cdot x + \frac{1}{2}, x, 1\right) \cdot x} \]
                                7. lower-fma.f6486.9

                                  \[\leadsto \frac{1}{\mathsf{fma}\left(\mathsf{fma}\left(0.16666666666666666, x, 0.5\right), x, 1\right) \cdot x} \]
                              4. Applied rewrites86.9%

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

                              Alternative 9: 82.7% accurate, 8.3× speedup?

                              \[\begin{array}{l} \\ \frac{x - -1}{\mathsf{fma}\left(0.5, x, 1\right) \cdot x} \end{array} \]
                              (FPCore (x) :precision binary64 (/ (- x -1.0) (* (fma 0.5 x 1.0) x)))
                              double code(double x) {
                              	return (x - -1.0) / (fma(0.5, x, 1.0) * x);
                              }
                              
                              function code(x)
                              	return Float64(Float64(x - -1.0) / Float64(fma(0.5, x, 1.0) * x))
                              end
                              
                              code[x_] := N[(N[(x - -1.0), $MachinePrecision] / N[(N[(0.5 * x + 1.0), $MachinePrecision] * x), $MachinePrecision]), $MachinePrecision]
                              
                              \begin{array}{l}
                              
                              \\
                              \frac{x - -1}{\mathsf{fma}\left(0.5, x, 1\right) \cdot x}
                              \end{array}
                              
                              Derivation
                              1. Initial program 35.5%

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

                                \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
                              4. Step-by-step derivation
                                1. Applied rewrites98.3%

                                  \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
                                2. Taylor expanded in x around 0

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

                                    \[\leadsto \frac{x + \color{blue}{1}}{x} \]
                                  2. metadata-evalN/A

                                    \[\leadsto \frac{x + 1 \cdot \color{blue}{1}}{x} \]
                                  3. fp-cancel-sign-sub-invN/A

                                    \[\leadsto \frac{x - \color{blue}{\left(\mathsf{neg}\left(1\right)\right) \cdot 1}}{x} \]
                                  4. metadata-evalN/A

                                    \[\leadsto \frac{x - -1 \cdot 1}{x} \]
                                  5. metadata-evalN/A

                                    \[\leadsto \frac{x - -1}{x} \]
                                  6. lower--.f6468.2

                                    \[\leadsto \frac{x - \color{blue}{-1}}{x} \]
                                4. Applied rewrites68.2%

                                  \[\leadsto \frac{\color{blue}{x - -1}}{x} \]
                                5. Taylor expanded in x around 0

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

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

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

                                    \[\leadsto \frac{x - -1}{\left(\frac{1}{2} \cdot x + 1\right) \cdot x} \]
                                  4. lower-fma.f6482.3

                                    \[\leadsto \frac{x - -1}{\mathsf{fma}\left(0.5, x, 1\right) \cdot x} \]
                                7. Applied rewrites82.3%

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

                                Alternative 10: 82.2% accurate, 9.3× speedup?

                                \[\begin{array}{l} \\ \frac{1}{\mathsf{fma}\left(0.5, x, 1\right) \cdot x} \end{array} \]
                                (FPCore (x) :precision binary64 (/ 1.0 (* (fma 0.5 x 1.0) x)))
                                double code(double x) {
                                	return 1.0 / (fma(0.5, x, 1.0) * x);
                                }
                                
                                function code(x)
                                	return Float64(1.0 / Float64(fma(0.5, x, 1.0) * x))
                                end
                                
                                code[x_] := N[(1.0 / N[(N[(0.5 * x + 1.0), $MachinePrecision] * x), $MachinePrecision]), $MachinePrecision]
                                
                                \begin{array}{l}
                                
                                \\
                                \frac{1}{\mathsf{fma}\left(0.5, x, 1\right) \cdot x}
                                \end{array}
                                
                                Derivation
                                1. Initial program 35.5%

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

                                  \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
                                4. Step-by-step derivation
                                  1. Applied rewrites98.3%

                                    \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
                                  2. Taylor expanded in x around 0

                                    \[\leadsto \frac{\color{blue}{1}}{x} \]
                                  3. Step-by-step derivation
                                    1. Applied rewrites68.8%

                                      \[\leadsto \frac{\color{blue}{1}}{x} \]
                                    2. Taylor expanded in x around 0

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

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

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

                                        \[\leadsto \frac{1}{\left(\frac{1}{2} \cdot x + 1\right) \cdot x} \]
                                      4. lower-fma.f6482.0

                                        \[\leadsto \frac{1}{\mathsf{fma}\left(0.5, x, 1\right) \cdot x} \]
                                    4. Applied rewrites82.0%

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

                                    Alternative 11: 66.9% accurate, 17.9× speedup?

                                    \[\begin{array}{l} \\ \frac{1}{x} \end{array} \]
                                    (FPCore (x) :precision binary64 (/ 1.0 x))
                                    double code(double x) {
                                    	return 1.0 / x;
                                    }
                                    
                                    module fmin_fmax_functions
                                        implicit none
                                        private
                                        public fmax
                                        public fmin
                                    
                                        interface fmax
                                            module procedure fmax88
                                            module procedure fmax44
                                            module procedure fmax84
                                            module procedure fmax48
                                        end interface
                                        interface fmin
                                            module procedure fmin88
                                            module procedure fmin44
                                            module procedure fmin84
                                            module procedure fmin48
                                        end interface
                                    contains
                                        real(8) function fmax88(x, y) result (res)
                                            real(8), intent (in) :: x
                                            real(8), intent (in) :: y
                                            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                        end function
                                        real(4) function fmax44(x, y) result (res)
                                            real(4), intent (in) :: x
                                            real(4), intent (in) :: y
                                            res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                        end function
                                        real(8) function fmax84(x, y) result(res)
                                            real(8), intent (in) :: x
                                            real(4), intent (in) :: y
                                            res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                        end function
                                        real(8) function fmax48(x, y) result(res)
                                            real(4), intent (in) :: x
                                            real(8), intent (in) :: y
                                            res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                        end function
                                        real(8) function fmin88(x, y) result (res)
                                            real(8), intent (in) :: x
                                            real(8), intent (in) :: y
                                            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                        end function
                                        real(4) function fmin44(x, y) result (res)
                                            real(4), intent (in) :: x
                                            real(4), intent (in) :: y
                                            res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                        end function
                                        real(8) function fmin84(x, y) result(res)
                                            real(8), intent (in) :: x
                                            real(4), intent (in) :: y
                                            res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                        end function
                                        real(8) function fmin48(x, y) result(res)
                                            real(4), intent (in) :: x
                                            real(8), intent (in) :: y
                                            res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                        end function
                                    end module
                                    
                                    real(8) function code(x)
                                    use fmin_fmax_functions
                                        real(8), intent (in) :: x
                                        code = 1.0d0 / x
                                    end function
                                    
                                    public static double code(double x) {
                                    	return 1.0 / x;
                                    }
                                    
                                    def code(x):
                                    	return 1.0 / x
                                    
                                    function code(x)
                                    	return Float64(1.0 / x)
                                    end
                                    
                                    function tmp = code(x)
                                    	tmp = 1.0 / x;
                                    end
                                    
                                    code[x_] := N[(1.0 / x), $MachinePrecision]
                                    
                                    \begin{array}{l}
                                    
                                    \\
                                    \frac{1}{x}
                                    \end{array}
                                    
                                    Derivation
                                    1. Initial program 35.5%

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

                                      \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
                                    4. Step-by-step derivation
                                      1. Applied rewrites98.3%

                                        \[\leadsto \frac{e^{x}}{\color{blue}{x}} \]
                                      2. Taylor expanded in x around 0

                                        \[\leadsto \frac{\color{blue}{1}}{x} \]
                                      3. Step-by-step derivation
                                        1. Applied rewrites68.8%

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

                                        Alternative 12: 3.2% accurate, 215.0× speedup?

                                        \[\begin{array}{l} \\ 0.5 \end{array} \]
                                        (FPCore (x) :precision binary64 0.5)
                                        double code(double x) {
                                        	return 0.5;
                                        }
                                        
                                        module fmin_fmax_functions
                                            implicit none
                                            private
                                            public fmax
                                            public fmin
                                        
                                            interface fmax
                                                module procedure fmax88
                                                module procedure fmax44
                                                module procedure fmax84
                                                module procedure fmax48
                                            end interface
                                            interface fmin
                                                module procedure fmin88
                                                module procedure fmin44
                                                module procedure fmin84
                                                module procedure fmin48
                                            end interface
                                        contains
                                            real(8) function fmax88(x, y) result (res)
                                                real(8), intent (in) :: x
                                                real(8), intent (in) :: y
                                                res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                            end function
                                            real(4) function fmax44(x, y) result (res)
                                                real(4), intent (in) :: x
                                                real(4), intent (in) :: y
                                                res = merge(y, merge(x, max(x, y), y /= y), x /= x)
                                            end function
                                            real(8) function fmax84(x, y) result(res)
                                                real(8), intent (in) :: x
                                                real(4), intent (in) :: y
                                                res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
                                            end function
                                            real(8) function fmax48(x, y) result(res)
                                                real(4), intent (in) :: x
                                                real(8), intent (in) :: y
                                                res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
                                            end function
                                            real(8) function fmin88(x, y) result (res)
                                                real(8), intent (in) :: x
                                                real(8), intent (in) :: y
                                                res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                            end function
                                            real(4) function fmin44(x, y) result (res)
                                                real(4), intent (in) :: x
                                                real(4), intent (in) :: y
                                                res = merge(y, merge(x, min(x, y), y /= y), x /= x)
                                            end function
                                            real(8) function fmin84(x, y) result(res)
                                                real(8), intent (in) :: x
                                                real(4), intent (in) :: y
                                                res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
                                            end function
                                            real(8) function fmin48(x, y) result(res)
                                                real(4), intent (in) :: x
                                                real(8), intent (in) :: y
                                                res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
                                            end function
                                        end module
                                        
                                        real(8) function code(x)
                                        use fmin_fmax_functions
                                            real(8), intent (in) :: x
                                            code = 0.5d0
                                        end function
                                        
                                        public static double code(double x) {
                                        	return 0.5;
                                        }
                                        
                                        def code(x):
                                        	return 0.5
                                        
                                        function code(x)
                                        	return 0.5
                                        end
                                        
                                        function tmp = code(x)
                                        	tmp = 0.5;
                                        end
                                        
                                        code[x_] := 0.5
                                        
                                        \begin{array}{l}
                                        
                                        \\
                                        0.5
                                        \end{array}
                                        
                                        Derivation
                                        1. Initial program 35.5%

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

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

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

                                            \[\leadsto \frac{\frac{1}{2} \cdot x + 1}{x} \]
                                          3. lower-fma.f6468.6

                                            \[\leadsto \frac{\mathsf{fma}\left(0.5, x, 1\right)}{x} \]
                                        5. Applied rewrites68.6%

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

                                          \[\leadsto \frac{1}{2} \]
                                        7. Step-by-step derivation
                                          1. Applied rewrites3.4%

                                            \[\leadsto 0.5 \]
                                          2. Add Preprocessing

                                          Reproduce

                                          ?
                                          herbie shell --seed 2025085 
                                          (FPCore (x)
                                            :name "expq2 (section 3.11)"
                                            :precision binary64
                                            :pre (> 710.0 x)
                                          
                                            :alt
                                            (! :herbie-platform default (/ (- 1) (expm1 (- x))))
                                          
                                            (/ (exp x) (- (exp x) 1.0)))