Asymptote C

Percentage Accurate: 55.2% → 99.7%
Time: 4.6s
Alternatives: 8
Speedup: 0.7×

Specification

?
\[\begin{array}{l} \\ \frac{x}{x + 1} - \frac{x + 1}{x - 1} \end{array} \]
(FPCore (x) :precision binary64 (- (/ x (+ x 1.0)) (/ (+ x 1.0) (- x 1.0))))
double code(double x) {
	return (x / (x + 1.0)) - ((x + 1.0) / (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 = (x / (x + 1.0d0)) - ((x + 1.0d0) / (x - 1.0d0))
end function
public static double code(double x) {
	return (x / (x + 1.0)) - ((x + 1.0) / (x - 1.0));
}
def code(x):
	return (x / (x + 1.0)) - ((x + 1.0) / (x - 1.0))
function code(x)
	return Float64(Float64(x / Float64(x + 1.0)) - Float64(Float64(x + 1.0) / Float64(x - 1.0)))
end
function tmp = code(x)
	tmp = (x / (x + 1.0)) - ((x + 1.0) / (x - 1.0));
end
code[x_] := N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(N[(x + 1.0), $MachinePrecision] / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{x}{x + 1} - \frac{x + 1}{x - 1}
\end{array}

Sampling outcomes in binary64 precision:

Local Percentage Accuracy vs ?

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

Accuracy vs Speed?

Herbie found 8 alternatives:

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

Initial Program: 55.2% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{x}{x + 1} - \frac{x + 1}{x - 1} \end{array} \]
(FPCore (x) :precision binary64 (- (/ x (+ x 1.0)) (/ (+ x 1.0) (- x 1.0))))
double code(double x) {
	return (x / (x + 1.0)) - ((x + 1.0) / (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 = (x / (x + 1.0d0)) - ((x + 1.0d0) / (x - 1.0d0))
end function
public static double code(double x) {
	return (x / (x + 1.0)) - ((x + 1.0) / (x - 1.0));
}
def code(x):
	return (x / (x + 1.0)) - ((x + 1.0) / (x - 1.0))
function code(x)
	return Float64(Float64(x / Float64(x + 1.0)) - Float64(Float64(x + 1.0) / Float64(x - 1.0)))
end
function tmp = code(x)
	tmp = (x / (x + 1.0)) - ((x + 1.0) / (x - 1.0));
end
code[x_] := N[(N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision] - N[(N[(x + 1.0), $MachinePrecision] / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{x}{x + 1} - \frac{x + 1}{x - 1}
\end{array}

Alternative 1: 99.7% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x - -1} - \frac{x - -1}{x - 1}\\ \mathbf{if}\;t\_0 \leq 10^{-7}:\\ \;\;\;\;\frac{-3 - \frac{x - -3}{x \cdot x}}{x}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (- (/ x (- x -1.0)) (/ (- x -1.0) (- x 1.0)))))
   (if (<= t_0 1e-7) (/ (- -3.0 (/ (- x -3.0) (* x x))) x) t_0)))
double code(double x) {
	double t_0 = (x / (x - -1.0)) - ((x - -1.0) / (x - 1.0));
	double tmp;
	if (t_0 <= 1e-7) {
		tmp = (-3.0 - ((x - -3.0) / (x * x))) / x;
	} else {
		tmp = t_0;
	}
	return tmp;
}
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
    real(8) :: t_0
    real(8) :: tmp
    t_0 = (x / (x - (-1.0d0))) - ((x - (-1.0d0)) / (x - 1.0d0))
    if (t_0 <= 1d-7) then
        tmp = ((-3.0d0) - ((x - (-3.0d0)) / (x * x))) / x
    else
        tmp = t_0
    end if
    code = tmp
end function
public static double code(double x) {
	double t_0 = (x / (x - -1.0)) - ((x - -1.0) / (x - 1.0));
	double tmp;
	if (t_0 <= 1e-7) {
		tmp = (-3.0 - ((x - -3.0) / (x * x))) / x;
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x):
	t_0 = (x / (x - -1.0)) - ((x - -1.0) / (x - 1.0))
	tmp = 0
	if t_0 <= 1e-7:
		tmp = (-3.0 - ((x - -3.0) / (x * x))) / x
	else:
		tmp = t_0
	return tmp
function code(x)
	t_0 = Float64(Float64(x / Float64(x - -1.0)) - Float64(Float64(x - -1.0) / Float64(x - 1.0)))
	tmp = 0.0
	if (t_0 <= 1e-7)
		tmp = Float64(Float64(-3.0 - Float64(Float64(x - -3.0) / Float64(x * x))) / x);
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x)
	t_0 = (x / (x - -1.0)) - ((x - -1.0) / (x - 1.0));
	tmp = 0.0;
	if (t_0 <= 1e-7)
		tmp = (-3.0 - ((x - -3.0) / (x * x))) / x;
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_] := Block[{t$95$0 = N[(N[(x / N[(x - -1.0), $MachinePrecision]), $MachinePrecision] - N[(N[(x - -1.0), $MachinePrecision] / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 1e-7], N[(N[(-3.0 - N[(N[(x - -3.0), $MachinePrecision] / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], t$95$0]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x - -1} - \frac{x - -1}{x - 1}\\
\mathbf{if}\;t\_0 \leq 10^{-7}:\\
\;\;\;\;\frac{-3 - \frac{x - -3}{x \cdot x}}{x}\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64)))) < 9.9999999999999995e-8

    1. Initial program 9.4%

      \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
    2. Add Preprocessing
    3. Taylor expanded in x around inf

      \[\leadsto \color{blue}{\frac{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} - 3}{x}} \]
    4. Applied rewrites99.2%

      \[\leadsto \color{blue}{\frac{-3 - \frac{\frac{x - -3}{x}}{x}}{x}} \]
    5. Step-by-step derivation
      1. Applied rewrites99.2%

        \[\leadsto \frac{-3 - \frac{x - -3}{x \cdot x}}{x} \]

      if 9.9999999999999995e-8 < (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64))))

      1. Initial program 100.0%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Add Preprocessing
    6. Recombined 2 regimes into one program.
    7. Final simplification99.5%

      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\ \;\;\;\;\frac{-3 - \frac{x - -3}{x \cdot x}}{x}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{x - -1} - \frac{x - -1}{x - 1}\\ \end{array} \]
    8. Add Preprocessing

    Alternative 2: 99.0% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\ \;\;\;\;\frac{-3 - \frac{x - -3}{x \cdot x}}{x}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), 3, x\right), 1\right)\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (if (<= (- (/ x (- x -1.0)) (/ (- x -1.0) (- x 1.0))) 1e-7)
       (/ (- -3.0 (/ (- x -3.0) (* x x))) x)
       (fma x (fma (fma x x 1.0) 3.0 x) 1.0)))
    double code(double x) {
    	double tmp;
    	if (((x / (x - -1.0)) - ((x - -1.0) / (x - 1.0))) <= 1e-7) {
    		tmp = (-3.0 - ((x - -3.0) / (x * x))) / x;
    	} else {
    		tmp = fma(x, fma(fma(x, x, 1.0), 3.0, x), 1.0);
    	}
    	return tmp;
    }
    
    function code(x)
    	tmp = 0.0
    	if (Float64(Float64(x / Float64(x - -1.0)) - Float64(Float64(x - -1.0) / Float64(x - 1.0))) <= 1e-7)
    		tmp = Float64(Float64(-3.0 - Float64(Float64(x - -3.0) / Float64(x * x))) / x);
    	else
    		tmp = fma(x, fma(fma(x, x, 1.0), 3.0, x), 1.0);
    	end
    	return tmp
    end
    
    code[x_] := If[LessEqual[N[(N[(x / N[(x - -1.0), $MachinePrecision]), $MachinePrecision] - N[(N[(x - -1.0), $MachinePrecision] / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1e-7], N[(N[(-3.0 - N[(N[(x - -3.0), $MachinePrecision] / N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], N[(x * N[(N[(x * x + 1.0), $MachinePrecision] * 3.0 + x), $MachinePrecision] + 1.0), $MachinePrecision]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\
    \;\;\;\;\frac{-3 - \frac{x - -3}{x \cdot x}}{x}\\
    
    \mathbf{else}:\\
    \;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), 3, x\right), 1\right)\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64)))) < 9.9999999999999995e-8

      1. Initial program 9.4%

        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
      2. Add Preprocessing
      3. Taylor expanded in x around inf

        \[\leadsto \color{blue}{\frac{-1 \cdot \frac{1 + 3 \cdot \frac{1}{x}}{x} - 3}{x}} \]
      4. Applied rewrites99.2%

        \[\leadsto \color{blue}{\frac{-3 - \frac{\frac{x - -3}{x}}{x}}{x}} \]
      5. Step-by-step derivation
        1. Applied rewrites99.2%

          \[\leadsto \frac{-3 - \frac{x - -3}{x \cdot x}}{x} \]

        if 9.9999999999999995e-8 < (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64))))

        1. Initial program 100.0%

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

          \[\leadsto \color{blue}{1 + x \cdot \left(3 + x \cdot \left(1 + 3 \cdot x\right)\right)} \]
        4. Step-by-step derivation
          1. Applied rewrites98.8%

            \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, 1\right) \cdot \mathsf{fma}\left(3, x, 1\right)} \]
          2. Step-by-step derivation
            1. Applied rewrites98.8%

              \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), \color{blue}{3 \cdot x}, \mathsf{fma}\left(x, x, 1\right)\right) \]
            2. Step-by-step derivation
              1. Applied rewrites98.8%

                \[\leadsto \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), 3, x\right)}, 1\right) \]
            3. Recombined 2 regimes into one program.
            4. Final simplification99.0%

              \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\ \;\;\;\;\frac{-3 - \frac{x - -3}{x \cdot x}}{x}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), 3, x\right), 1\right)\\ \end{array} \]
            5. Add Preprocessing

            Alternative 3: 98.9% accurate, 0.5× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\ \;\;\;\;\frac{-3 - \frac{1}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), 3, x\right), 1\right)\\ \end{array} \end{array} \]
            (FPCore (x)
             :precision binary64
             (if (<= (- (/ x (- x -1.0)) (/ (- x -1.0) (- x 1.0))) 1e-7)
               (/ (- -3.0 (/ 1.0 x)) x)
               (fma x (fma (fma x x 1.0) 3.0 x) 1.0)))
            double code(double x) {
            	double tmp;
            	if (((x / (x - -1.0)) - ((x - -1.0) / (x - 1.0))) <= 1e-7) {
            		tmp = (-3.0 - (1.0 / x)) / x;
            	} else {
            		tmp = fma(x, fma(fma(x, x, 1.0), 3.0, x), 1.0);
            	}
            	return tmp;
            }
            
            function code(x)
            	tmp = 0.0
            	if (Float64(Float64(x / Float64(x - -1.0)) - Float64(Float64(x - -1.0) / Float64(x - 1.0))) <= 1e-7)
            		tmp = Float64(Float64(-3.0 - Float64(1.0 / x)) / x);
            	else
            		tmp = fma(x, fma(fma(x, x, 1.0), 3.0, x), 1.0);
            	end
            	return tmp
            end
            
            code[x_] := If[LessEqual[N[(N[(x / N[(x - -1.0), $MachinePrecision]), $MachinePrecision] - N[(N[(x - -1.0), $MachinePrecision] / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1e-7], N[(N[(-3.0 - N[(1.0 / x), $MachinePrecision]), $MachinePrecision] / x), $MachinePrecision], N[(x * N[(N[(x * x + 1.0), $MachinePrecision] * 3.0 + x), $MachinePrecision] + 1.0), $MachinePrecision]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\
            \;\;\;\;\frac{-3 - \frac{1}{x}}{x}\\
            
            \mathbf{else}:\\
            \;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), 3, x\right), 1\right)\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 2 regimes
            2. if (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64)))) < 9.9999999999999995e-8

              1. Initial program 9.4%

                \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
              2. Add Preprocessing
              3. Taylor expanded in x around inf

                \[\leadsto \color{blue}{-1 \cdot \frac{3 + \frac{1}{x}}{x}} \]
              4. Step-by-step derivation
                1. Applied rewrites98.8%

                  \[\leadsto \color{blue}{\frac{-3 - \frac{1}{x}}{x}} \]

                if 9.9999999999999995e-8 < (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64))))

                1. Initial program 100.0%

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

                  \[\leadsto \color{blue}{1 + x \cdot \left(3 + x \cdot \left(1 + 3 \cdot x\right)\right)} \]
                4. Step-by-step derivation
                  1. Applied rewrites98.8%

                    \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, 1\right) \cdot \mathsf{fma}\left(3, x, 1\right)} \]
                  2. Step-by-step derivation
                    1. Applied rewrites98.8%

                      \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), \color{blue}{3 \cdot x}, \mathsf{fma}\left(x, x, 1\right)\right) \]
                    2. Step-by-step derivation
                      1. Applied rewrites98.8%

                        \[\leadsto \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), 3, x\right)}, 1\right) \]
                    3. Recombined 2 regimes into one program.
                    4. Final simplification98.8%

                      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\ \;\;\;\;\frac{-3 - \frac{1}{x}}{x}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), 3, x\right), 1\right)\\ \end{array} \]
                    5. Add Preprocessing

                    Alternative 4: 98.5% accurate, 0.6× speedup?

                    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), 3, x\right), 1\right)\\ \end{array} \end{array} \]
                    (FPCore (x)
                     :precision binary64
                     (if (<= (- (/ x (- x -1.0)) (/ (- x -1.0) (- x 1.0))) 1e-7)
                       (/ -3.0 x)
                       (fma x (fma (fma x x 1.0) 3.0 x) 1.0)))
                    double code(double x) {
                    	double tmp;
                    	if (((x / (x - -1.0)) - ((x - -1.0) / (x - 1.0))) <= 1e-7) {
                    		tmp = -3.0 / x;
                    	} else {
                    		tmp = fma(x, fma(fma(x, x, 1.0), 3.0, x), 1.0);
                    	}
                    	return tmp;
                    }
                    
                    function code(x)
                    	tmp = 0.0
                    	if (Float64(Float64(x / Float64(x - -1.0)) - Float64(Float64(x - -1.0) / Float64(x - 1.0))) <= 1e-7)
                    		tmp = Float64(-3.0 / x);
                    	else
                    		tmp = fma(x, fma(fma(x, x, 1.0), 3.0, x), 1.0);
                    	end
                    	return tmp
                    end
                    
                    code[x_] := If[LessEqual[N[(N[(x / N[(x - -1.0), $MachinePrecision]), $MachinePrecision] - N[(N[(x - -1.0), $MachinePrecision] / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1e-7], N[(-3.0 / x), $MachinePrecision], N[(x * N[(N[(x * x + 1.0), $MachinePrecision] * 3.0 + x), $MachinePrecision] + 1.0), $MachinePrecision]]
                    
                    \begin{array}{l}
                    
                    \\
                    \begin{array}{l}
                    \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\
                    \;\;\;\;\frac{-3}{x}\\
                    
                    \mathbf{else}:\\
                    \;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), 3, x\right), 1\right)\\
                    
                    
                    \end{array}
                    \end{array}
                    
                    Derivation
                    1. Split input into 2 regimes
                    2. if (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64)))) < 9.9999999999999995e-8

                      1. Initial program 9.4%

                        \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
                      2. Add Preprocessing
                      3. Taylor expanded in x around inf

                        \[\leadsto \color{blue}{\frac{-3}{x}} \]
                      4. Step-by-step derivation
                        1. Applied rewrites97.5%

                          \[\leadsto \color{blue}{\frac{-3}{x}} \]

                        if 9.9999999999999995e-8 < (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64))))

                        1. Initial program 100.0%

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

                          \[\leadsto \color{blue}{1 + x \cdot \left(3 + x \cdot \left(1 + 3 \cdot x\right)\right)} \]
                        4. Step-by-step derivation
                          1. Applied rewrites98.8%

                            \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, 1\right) \cdot \mathsf{fma}\left(3, x, 1\right)} \]
                          2. Step-by-step derivation
                            1. Applied rewrites98.8%

                              \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), \color{blue}{3 \cdot x}, \mathsf{fma}\left(x, x, 1\right)\right) \]
                            2. Step-by-step derivation
                              1. Applied rewrites98.8%

                                \[\leadsto \mathsf{fma}\left(x, \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), 3, x\right)}, 1\right) \]
                            3. Recombined 2 regimes into one program.
                            4. Final simplification98.1%

                              \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(x, \mathsf{fma}\left(\mathsf{fma}\left(x, x, 1\right), 3, x\right), 1\right)\\ \end{array} \]
                            5. Add Preprocessing

                            Alternative 5: 98.5% accurate, 0.6× speedup?

                            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(x, x, 1\right) \cdot \mathsf{fma}\left(3, x, 1\right)\\ \end{array} \end{array} \]
                            (FPCore (x)
                             :precision binary64
                             (if (<= (- (/ x (- x -1.0)) (/ (- x -1.0) (- x 1.0))) 1e-7)
                               (/ -3.0 x)
                               (* (fma x x 1.0) (fma 3.0 x 1.0))))
                            double code(double x) {
                            	double tmp;
                            	if (((x / (x - -1.0)) - ((x - -1.0) / (x - 1.0))) <= 1e-7) {
                            		tmp = -3.0 / x;
                            	} else {
                            		tmp = fma(x, x, 1.0) * fma(3.0, x, 1.0);
                            	}
                            	return tmp;
                            }
                            
                            function code(x)
                            	tmp = 0.0
                            	if (Float64(Float64(x / Float64(x - -1.0)) - Float64(Float64(x - -1.0) / Float64(x - 1.0))) <= 1e-7)
                            		tmp = Float64(-3.0 / x);
                            	else
                            		tmp = Float64(fma(x, x, 1.0) * fma(3.0, x, 1.0));
                            	end
                            	return tmp
                            end
                            
                            code[x_] := If[LessEqual[N[(N[(x / N[(x - -1.0), $MachinePrecision]), $MachinePrecision] - N[(N[(x - -1.0), $MachinePrecision] / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1e-7], N[(-3.0 / x), $MachinePrecision], N[(N[(x * x + 1.0), $MachinePrecision] * N[(3.0 * x + 1.0), $MachinePrecision]), $MachinePrecision]]
                            
                            \begin{array}{l}
                            
                            \\
                            \begin{array}{l}
                            \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\
                            \;\;\;\;\frac{-3}{x}\\
                            
                            \mathbf{else}:\\
                            \;\;\;\;\mathsf{fma}\left(x, x, 1\right) \cdot \mathsf{fma}\left(3, x, 1\right)\\
                            
                            
                            \end{array}
                            \end{array}
                            
                            Derivation
                            1. Split input into 2 regimes
                            2. if (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64)))) < 9.9999999999999995e-8

                              1. Initial program 9.4%

                                \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
                              2. Add Preprocessing
                              3. Taylor expanded in x around inf

                                \[\leadsto \color{blue}{\frac{-3}{x}} \]
                              4. Step-by-step derivation
                                1. Applied rewrites97.5%

                                  \[\leadsto \color{blue}{\frac{-3}{x}} \]

                                if 9.9999999999999995e-8 < (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64))))

                                1. Initial program 100.0%

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

                                  \[\leadsto \color{blue}{1 + x \cdot \left(3 + x \cdot \left(1 + 3 \cdot x\right)\right)} \]
                                4. Step-by-step derivation
                                  1. Applied rewrites98.8%

                                    \[\leadsto \color{blue}{\mathsf{fma}\left(x, x, 1\right) \cdot \mathsf{fma}\left(3, x, 1\right)} \]
                                5. Recombined 2 regimes into one program.
                                6. Final simplification98.1%

                                  \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(x, x, 1\right) \cdot \mathsf{fma}\left(3, x, 1\right)\\ \end{array} \]
                                7. Add Preprocessing

                                Alternative 6: 98.5% accurate, 0.7× speedup?

                                \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(x - -3, x, 1\right)\\ \end{array} \end{array} \]
                                (FPCore (x)
                                 :precision binary64
                                 (if (<= (- (/ x (- x -1.0)) (/ (- x -1.0) (- x 1.0))) 1e-7)
                                   (/ -3.0 x)
                                   (fma (- x -3.0) x 1.0)))
                                double code(double x) {
                                	double tmp;
                                	if (((x / (x - -1.0)) - ((x - -1.0) / (x - 1.0))) <= 1e-7) {
                                		tmp = -3.0 / x;
                                	} else {
                                		tmp = fma((x - -3.0), x, 1.0);
                                	}
                                	return tmp;
                                }
                                
                                function code(x)
                                	tmp = 0.0
                                	if (Float64(Float64(x / Float64(x - -1.0)) - Float64(Float64(x - -1.0) / Float64(x - 1.0))) <= 1e-7)
                                		tmp = Float64(-3.0 / x);
                                	else
                                		tmp = fma(Float64(x - -3.0), x, 1.0);
                                	end
                                	return tmp
                                end
                                
                                code[x_] := If[LessEqual[N[(N[(x / N[(x - -1.0), $MachinePrecision]), $MachinePrecision] - N[(N[(x - -1.0), $MachinePrecision] / N[(x - 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], 1e-7], N[(-3.0 / x), $MachinePrecision], N[(N[(x - -3.0), $MachinePrecision] * x + 1.0), $MachinePrecision]]
                                
                                \begin{array}{l}
                                
                                \\
                                \begin{array}{l}
                                \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\
                                \;\;\;\;\frac{-3}{x}\\
                                
                                \mathbf{else}:\\
                                \;\;\;\;\mathsf{fma}\left(x - -3, x, 1\right)\\
                                
                                
                                \end{array}
                                \end{array}
                                
                                Derivation
                                1. Split input into 2 regimes
                                2. if (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64)))) < 9.9999999999999995e-8

                                  1. Initial program 9.4%

                                    \[\frac{x}{x + 1} - \frac{x + 1}{x - 1} \]
                                  2. Add Preprocessing
                                  3. Taylor expanded in x around inf

                                    \[\leadsto \color{blue}{\frac{-3}{x}} \]
                                  4. Step-by-step derivation
                                    1. Applied rewrites97.5%

                                      \[\leadsto \color{blue}{\frac{-3}{x}} \]

                                    if 9.9999999999999995e-8 < (-.f64 (/.f64 x (+.f64 x #s(literal 1 binary64))) (/.f64 (+.f64 x #s(literal 1 binary64)) (-.f64 x #s(literal 1 binary64))))

                                    1. Initial program 100.0%

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

                                      \[\leadsto \color{blue}{1 + x \cdot \left(3 + x\right)} \]
                                    4. Step-by-step derivation
                                      1. Applied rewrites98.3%

                                        \[\leadsto \color{blue}{\mathsf{fma}\left(x - -3, x, 1\right)} \]
                                    5. Recombined 2 regimes into one program.
                                    6. Final simplification97.9%

                                      \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x}{x - -1} - \frac{x - -1}{x - 1} \leq 10^{-7}:\\ \;\;\;\;\frac{-3}{x}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(x - -3, x, 1\right)\\ \end{array} \]
                                    7. Add Preprocessing

                                    Alternative 7: 51.7% accurate, 3.5× speedup?

                                    \[\begin{array}{l} \\ \mathsf{fma}\left(x - -3, x, 1\right) \end{array} \]
                                    (FPCore (x) :precision binary64 (fma (- x -3.0) x 1.0))
                                    double code(double x) {
                                    	return fma((x - -3.0), x, 1.0);
                                    }
                                    
                                    function code(x)
                                    	return fma(Float64(x - -3.0), x, 1.0)
                                    end
                                    
                                    code[x_] := N[(N[(x - -3.0), $MachinePrecision] * x + 1.0), $MachinePrecision]
                                    
                                    \begin{array}{l}
                                    
                                    \\
                                    \mathsf{fma}\left(x - -3, x, 1\right)
                                    \end{array}
                                    
                                    Derivation
                                    1. Initial program 53.6%

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

                                      \[\leadsto \color{blue}{1 + x \cdot \left(3 + x\right)} \]
                                    4. Step-by-step derivation
                                      1. Applied rewrites49.2%

                                        \[\leadsto \color{blue}{\mathsf{fma}\left(x - -3, x, 1\right)} \]
                                      2. Add Preprocessing

                                      Alternative 8: 51.7% accurate, 35.0× speedup?

                                      \[\begin{array}{l} \\ 1 \end{array} \]
                                      (FPCore (x) :precision binary64 1.0)
                                      double code(double x) {
                                      	return 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 = 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 53.6%

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

                                        \[\leadsto \color{blue}{1} \]
                                      4. Step-by-step derivation
                                        1. Applied rewrites48.8%

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

                                        Reproduce

                                        ?
                                        herbie shell --seed 2025019 
                                        (FPCore (x)
                                          :name "Asymptote C"
                                          :precision binary64
                                          (- (/ x (+ x 1.0)) (/ (+ x 1.0) (- x 1.0))))