Asymptote B

Percentage Accurate: 100.0% → 100.0%
Time: 2.2s
Alternatives: 8
Speedup: 1.0×

Specification

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

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

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: 100.0% accurate, 1.0× speedup?

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

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

Alternative 1: 100.0% accurate, 1.0× speedup?

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

\\
\frac{1}{x - 1} + \frac{x}{x + 1}
\end{array}
Derivation
  1. Initial program 100.0%

    \[\frac{1}{x - 1} + \frac{x}{x + 1} \]
  2. Add Preprocessing
  3. Add Preprocessing

Alternative 2: 99.5% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1}\\ \mathbf{if}\;\frac{1}{x - 1} + t\_0 \leq 0.9999999999999999:\\ \;\;\;\;\frac{\mathsf{fma}\left(x - 1, x, x - -1\right)}{\mathsf{fma}\left(x, x, -1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{x} + t\_0\\ \end{array} \end{array} \]
(FPCore (x)
 :precision binary64
 (let* ((t_0 (/ x (+ x 1.0))))
   (if (<= (+ (/ 1.0 (- x 1.0)) t_0) 0.9999999999999999)
     (/ (fma (- x 1.0) x (- x -1.0)) (fma x x -1.0))
     (+ (/ 1.0 x) t_0))))
double code(double x) {
	double t_0 = x / (x + 1.0);
	double tmp;
	if (((1.0 / (x - 1.0)) + t_0) <= 0.9999999999999999) {
		tmp = fma((x - 1.0), x, (x - -1.0)) / fma(x, x, -1.0);
	} else {
		tmp = (1.0 / x) + t_0;
	}
	return tmp;
}
function code(x)
	t_0 = Float64(x / Float64(x + 1.0))
	tmp = 0.0
	if (Float64(Float64(1.0 / Float64(x - 1.0)) + t_0) <= 0.9999999999999999)
		tmp = Float64(fma(Float64(x - 1.0), x, Float64(x - -1.0)) / fma(x, x, -1.0));
	else
		tmp = Float64(Float64(1.0 / x) + t_0);
	end
	return tmp
end
code[x_] := Block[{t$95$0 = N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision] + t$95$0), $MachinePrecision], 0.9999999999999999], N[(N[(N[(x - 1.0), $MachinePrecision] * x + N[(x - -1.0), $MachinePrecision]), $MachinePrecision] / N[(x * x + -1.0), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / x), $MachinePrecision] + t$95$0), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x}{x + 1}\\
\mathbf{if}\;\frac{1}{x - 1} + t\_0 \leq 0.9999999999999999:\\
\;\;\;\;\frac{\mathsf{fma}\left(x - 1, x, x - -1\right)}{\mathsf{fma}\left(x, x, -1\right)}\\

\mathbf{else}:\\
\;\;\;\;\frac{1}{x} + t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (+.f64 (/.f64 #s(literal 1 binary64) (-.f64 x #s(literal 1 binary64))) (/.f64 x (+.f64 x #s(literal 1 binary64)))) < 0.999999999999999889

    1. Initial program 100.0%

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

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

        \[\leadsto \frac{1}{\color{blue}{x - 1}} + \frac{x}{x + 1} \]
      3. lift-/.f64N/A

        \[\leadsto \color{blue}{\frac{1}{x - 1}} + \frac{x}{x + 1} \]
      4. lift-+.f64N/A

        \[\leadsto \frac{1}{x - 1} + \frac{x}{\color{blue}{x + 1}} \]
      5. lift-/.f64N/A

        \[\leadsto \frac{1}{x - 1} + \color{blue}{\frac{x}{x + 1}} \]
      6. frac-addN/A

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

        \[\leadsto \frac{1 \cdot \left(x + 1\right) + \left(x - 1\right) \cdot x}{\color{blue}{\left(x + 1\right) \cdot \left(x - 1\right)}} \]
      8. difference-of-squaresN/A

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

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

        \[\leadsto \frac{1 \cdot \left(x + 1\right) + \color{blue}{x \cdot \left(x - 1\right)}}{x \cdot x - 1 \cdot 1} \]
      11. *-lft-identityN/A

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

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

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

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

        \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{x - 1}, x, x + 1\right)}{x \cdot x - 1 \cdot 1} \]
      16. metadata-evalN/A

        \[\leadsto \frac{\mathsf{fma}\left(x - 1, x, x + \color{blue}{1 \cdot 1}\right)}{x \cdot x - 1 \cdot 1} \]
      17. fp-cancel-sign-sub-invN/A

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

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

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

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

        \[\leadsto \frac{\mathsf{fma}\left(x - 1, x, x - -1\right)}{\color{blue}{{x}^{2}} - 1 \cdot 1} \]
      22. fp-cancel-sub-sign-invN/A

        \[\leadsto \frac{\mathsf{fma}\left(x - 1, x, x - -1\right)}{\color{blue}{{x}^{2} + \left(\mathsf{neg}\left(1\right)\right) \cdot 1}} \]
    4. Applied rewrites100.0%

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

    if 0.999999999999999889 < (+.f64 (/.f64 #s(literal 1 binary64) (-.f64 x #s(literal 1 binary64))) (/.f64 x (+.f64 x #s(literal 1 binary64))))

    1. Initial program 100.0%

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

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

        \[\leadsto \frac{1}{\color{blue}{x}} + \frac{x}{x + 1} \]
    5. Recombined 2 regimes into one program.
    6. Add Preprocessing

    Alternative 3: 99.5% accurate, 0.5× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x}{x + 1}\\ \mathbf{if}\;\frac{1}{x - 1} + t\_0 \leq 0.9999999999999999:\\ \;\;\;\;\frac{\mathsf{fma}\left(x, x, 1\right)}{\mathsf{fma}\left(x, x, -1\right)}\\ \mathbf{else}:\\ \;\;\;\;\frac{1}{x} + t\_0\\ \end{array} \end{array} \]
    (FPCore (x)
     :precision binary64
     (let* ((t_0 (/ x (+ x 1.0))))
       (if (<= (+ (/ 1.0 (- x 1.0)) t_0) 0.9999999999999999)
         (/ (fma x x 1.0) (fma x x -1.0))
         (+ (/ 1.0 x) t_0))))
    double code(double x) {
    	double t_0 = x / (x + 1.0);
    	double tmp;
    	if (((1.0 / (x - 1.0)) + t_0) <= 0.9999999999999999) {
    		tmp = fma(x, x, 1.0) / fma(x, x, -1.0);
    	} else {
    		tmp = (1.0 / x) + t_0;
    	}
    	return tmp;
    }
    
    function code(x)
    	t_0 = Float64(x / Float64(x + 1.0))
    	tmp = 0.0
    	if (Float64(Float64(1.0 / Float64(x - 1.0)) + t_0) <= 0.9999999999999999)
    		tmp = Float64(fma(x, x, 1.0) / fma(x, x, -1.0));
    	else
    		tmp = Float64(Float64(1.0 / x) + t_0);
    	end
    	return tmp
    end
    
    code[x_] := Block[{t$95$0 = N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision] + t$95$0), $MachinePrecision], 0.9999999999999999], N[(N[(x * x + 1.0), $MachinePrecision] / N[(x * x + -1.0), $MachinePrecision]), $MachinePrecision], N[(N[(1.0 / x), $MachinePrecision] + t$95$0), $MachinePrecision]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := \frac{x}{x + 1}\\
    \mathbf{if}\;\frac{1}{x - 1} + t\_0 \leq 0.9999999999999999:\\
    \;\;\;\;\frac{\mathsf{fma}\left(x, x, 1\right)}{\mathsf{fma}\left(x, x, -1\right)}\\
    
    \mathbf{else}:\\
    \;\;\;\;\frac{1}{x} + t\_0\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (+.f64 (/.f64 #s(literal 1 binary64) (-.f64 x #s(literal 1 binary64))) (/.f64 x (+.f64 x #s(literal 1 binary64)))) < 0.999999999999999889

      1. Initial program 100.0%

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

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

          \[\leadsto \frac{1}{\color{blue}{x - 1}} + \frac{x}{x + 1} \]
        3. lift-/.f64N/A

          \[\leadsto \color{blue}{\frac{1}{x - 1}} + \frac{x}{x + 1} \]
        4. lift-+.f64N/A

          \[\leadsto \frac{1}{x - 1} + \frac{x}{\color{blue}{x + 1}} \]
        5. lift-/.f64N/A

          \[\leadsto \frac{1}{x - 1} + \color{blue}{\frac{x}{x + 1}} \]
        6. frac-addN/A

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

          \[\leadsto \frac{1 \cdot \left(x + 1\right) + \left(x - 1\right) \cdot x}{\color{blue}{\left(x + 1\right) \cdot \left(x - 1\right)}} \]
        8. difference-of-squaresN/A

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

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

          \[\leadsto \frac{1 \cdot \left(x + 1\right) + \color{blue}{x \cdot \left(x - 1\right)}}{x \cdot x - 1 \cdot 1} \]
        11. *-lft-identityN/A

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

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

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

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

          \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{x - 1}, x, x + 1\right)}{x \cdot x - 1 \cdot 1} \]
        16. metadata-evalN/A

          \[\leadsto \frac{\mathsf{fma}\left(x - 1, x, x + \color{blue}{1 \cdot 1}\right)}{x \cdot x - 1 \cdot 1} \]
        17. fp-cancel-sign-sub-invN/A

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

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

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

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

          \[\leadsto \frac{\mathsf{fma}\left(x - 1, x, x - -1\right)}{\color{blue}{{x}^{2}} - 1 \cdot 1} \]
        22. fp-cancel-sub-sign-invN/A

          \[\leadsto \frac{\mathsf{fma}\left(x - 1, x, x - -1\right)}{\color{blue}{{x}^{2} + \left(\mathsf{neg}\left(1\right)\right) \cdot 1}} \]
      4. Applied rewrites100.0%

        \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x - 1, x, x - -1\right)}{\mathsf{fma}\left(x, x, -1\right)}} \]
      5. Taylor expanded in x around 0

        \[\leadsto \frac{\color{blue}{1 + {x}^{2}}}{\mathsf{fma}\left(x, x, -1\right)} \]
      6. Step-by-step derivation
        1. *-rgt-identityN/A

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

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

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

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

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

          \[\leadsto \frac{{x}^{2} + \color{blue}{{x}^{2}} \cdot \frac{1}{{x}^{2}}}{\mathsf{fma}\left(x, x, -1\right)} \]
        7. pow2N/A

          \[\leadsto \frac{x \cdot x + \color{blue}{{x}^{2}} \cdot \frac{1}{{x}^{2}}}{\mathsf{fma}\left(x, x, -1\right)} \]
        8. rgt-mult-inverseN/A

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

          \[\leadsto \frac{\mathsf{fma}\left(x, \color{blue}{x}, 1\right)}{\mathsf{fma}\left(x, x, -1\right)} \]
      7. Applied rewrites100.0%

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}{\mathsf{fma}\left(x, x, -1\right)} \]
      8. Step-by-step derivation
        1. Applied rewrites100.0%

          \[\leadsto \frac{\mathsf{fma}\left(x, x, 1\right)}{\mathsf{fma}\left(x, x, \color{blue}{-1}\right)} \]
        2. Step-by-step derivation
          1. Applied rewrites100.0%

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

          if 0.999999999999999889 < (+.f64 (/.f64 #s(literal 1 binary64) (-.f64 x #s(literal 1 binary64))) (/.f64 x (+.f64 x #s(literal 1 binary64))))

          1. Initial program 100.0%

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

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

              \[\leadsto \frac{1}{\color{blue}{x}} + \frac{x}{x + 1} \]
          5. Recombined 2 regimes into one program.
          6. Add Preprocessing

          Alternative 4: 99.3% accurate, 0.5× speedup?

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

            1. Initial program 100.0%

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

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

                \[\leadsto \frac{1}{\color{blue}{x - 1}} + \frac{x}{x + 1} \]
              3. lift-/.f64N/A

                \[\leadsto \color{blue}{\frac{1}{x - 1}} + \frac{x}{x + 1} \]
              4. lift-+.f64N/A

                \[\leadsto \frac{1}{x - 1} + \frac{x}{\color{blue}{x + 1}} \]
              5. lift-/.f64N/A

                \[\leadsto \frac{1}{x - 1} + \color{blue}{\frac{x}{x + 1}} \]
              6. frac-addN/A

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

                \[\leadsto \frac{1 \cdot \left(x + 1\right) + \left(x - 1\right) \cdot x}{\color{blue}{\left(x + 1\right) \cdot \left(x - 1\right)}} \]
              8. difference-of-squaresN/A

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

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

                \[\leadsto \frac{1 \cdot \left(x + 1\right) + \color{blue}{x \cdot \left(x - 1\right)}}{x \cdot x - 1 \cdot 1} \]
              11. *-lft-identityN/A

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

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

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

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

                \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{x - 1}, x, x + 1\right)}{x \cdot x - 1 \cdot 1} \]
              16. metadata-evalN/A

                \[\leadsto \frac{\mathsf{fma}\left(x - 1, x, x + \color{blue}{1 \cdot 1}\right)}{x \cdot x - 1 \cdot 1} \]
              17. fp-cancel-sign-sub-invN/A

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

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

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

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

                \[\leadsto \frac{\mathsf{fma}\left(x - 1, x, x - -1\right)}{\color{blue}{{x}^{2}} - 1 \cdot 1} \]
              22. fp-cancel-sub-sign-invN/A

                \[\leadsto \frac{\mathsf{fma}\left(x - 1, x, x - -1\right)}{\color{blue}{{x}^{2} + \left(\mathsf{neg}\left(1\right)\right) \cdot 1}} \]
            4. Applied rewrites100.0%

              \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x - 1, x, x - -1\right)}{\mathsf{fma}\left(x, x, -1\right)}} \]
            5. Taylor expanded in x around 0

              \[\leadsto \frac{\color{blue}{1 + {x}^{2}}}{\mathsf{fma}\left(x, x, -1\right)} \]
            6. Step-by-step derivation
              1. *-rgt-identityN/A

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

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

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

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

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

                \[\leadsto \frac{{x}^{2} + \color{blue}{{x}^{2}} \cdot \frac{1}{{x}^{2}}}{\mathsf{fma}\left(x, x, -1\right)} \]
              7. pow2N/A

                \[\leadsto \frac{x \cdot x + \color{blue}{{x}^{2}} \cdot \frac{1}{{x}^{2}}}{\mathsf{fma}\left(x, x, -1\right)} \]
              8. rgt-mult-inverseN/A

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

                \[\leadsto \frac{\mathsf{fma}\left(x, \color{blue}{x}, 1\right)}{\mathsf{fma}\left(x, x, -1\right)} \]
            7. Applied rewrites100.0%

              \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x, x, 1\right)}}{\mathsf{fma}\left(x, x, -1\right)} \]
            8. Step-by-step derivation
              1. Applied rewrites100.0%

                \[\leadsto \frac{\mathsf{fma}\left(x, x, 1\right)}{\mathsf{fma}\left(x, x, \color{blue}{-1}\right)} \]
              2. Step-by-step derivation
                1. Applied rewrites100.0%

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

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

                1. Initial program 100.0%

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

                  \[\leadsto \color{blue}{1} \]
                4. Step-by-step derivation
                  1. Applied rewrites98.5%

                    \[\leadsto \color{blue}{1} \]
                  2. Step-by-step derivation
                    1. Applied rewrites98.5%

                      \[\leadsto \color{blue}{1} \]
                    2. Step-by-step derivation
                      1. Applied rewrites98.5%

                        \[\leadsto \color{blue}{1} \]
                      2. Step-by-step derivation
                        1. Applied rewrites98.5%

                          \[\leadsto \color{blue}{1} \]
                      3. Recombined 2 regimes into one program.
                      4. Add Preprocessing

                      Alternative 5: 99.1% accurate, 0.5× speedup?

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

                        1. Initial program 100.0%

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

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

                            \[\leadsto {x}^{2} \cdot \left(-2 \cdot {x}^{2} - 2\right) - 1 \cdot \color{blue}{1} \]
                          2. fp-cancel-sub-sign-invN/A

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

                            \[\leadsto \left(-2 \cdot {x}^{2} - 2\right) \cdot {x}^{2} + \color{blue}{\left(\mathsf{neg}\left(1\right)\right)} \cdot 1 \]
                          4. metadata-evalN/A

                            \[\leadsto \left(-2 \cdot {x}^{2} - 2\right) \cdot {x}^{2} + -1 \cdot 1 \]
                          5. metadata-evalN/A

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

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

                            \[\leadsto \mathsf{fma}\left(-2 \cdot {x}^{2} - 2 \cdot 1, {x}^{2}, -1\right) \]
                          8. fp-cancel-sub-sign-invN/A

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

                            \[\leadsto \mathsf{fma}\left({x}^{2} \cdot -2 + \left(\mathsf{neg}\left(2\right)\right) \cdot 1, {x}^{2}, -1\right) \]
                          10. metadata-evalN/A

                            \[\leadsto \mathsf{fma}\left({x}^{2} \cdot -2 + -2 \cdot 1, {x}^{2}, -1\right) \]
                          11. metadata-evalN/A

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

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

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

                            \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, -2, -2\right), {x}^{2}, -1\right) \]
                          15. unpow2N/A

                            \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, -2, -2\right), x \cdot \color{blue}{x}, -1\right) \]
                          16. lower-*.f6499.7

                            \[\leadsto \mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, -2, -2\right), x \cdot \color{blue}{x}, -1\right) \]
                        5. Applied rewrites99.7%

                          \[\leadsto \color{blue}{\mathsf{fma}\left(\mathsf{fma}\left(x \cdot x, -2, -2\right), x \cdot x, -1\right)} \]

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

                        1. Initial program 100.0%

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

                          \[\leadsto \color{blue}{1} \]
                        4. Step-by-step derivation
                          1. Applied rewrites98.5%

                            \[\leadsto \color{blue}{1} \]
                          2. Step-by-step derivation
                            1. Applied rewrites98.5%

                              \[\leadsto \color{blue}{1} \]
                            2. Step-by-step derivation
                              1. Applied rewrites98.5%

                                \[\leadsto \color{blue}{1} \]
                              2. Step-by-step derivation
                                1. Applied rewrites98.5%

                                  \[\leadsto \color{blue}{1} \]
                              3. Recombined 2 regimes into one program.
                              4. Add Preprocessing

                              Alternative 6: 99.0% accurate, 0.7× speedup?

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

                                1. Initial program 100.0%

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

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

                                    \[\leadsto -2 \cdot {x}^{2} - 1 \cdot \color{blue}{1} \]
                                  2. fp-cancel-sub-sign-invN/A

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

                                    \[\leadsto {x}^{2} \cdot -2 + \color{blue}{\left(\mathsf{neg}\left(1\right)\right)} \cdot 1 \]
                                  4. metadata-evalN/A

                                    \[\leadsto {x}^{2} \cdot -2 + -1 \cdot 1 \]
                                  5. metadata-evalN/A

                                    \[\leadsto {x}^{2} \cdot -2 + -1 \]
                                  6. lower-fma.f64N/A

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

                                    \[\leadsto \mathsf{fma}\left(x \cdot x, -2, -1\right) \]
                                  8. lower-*.f6499.5

                                    \[\leadsto \mathsf{fma}\left(x \cdot x, -2, -1\right) \]
                                5. Applied rewrites99.5%

                                  \[\leadsto \color{blue}{\mathsf{fma}\left(x \cdot x, -2, -1\right)} \]

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

                                1. Initial program 100.0%

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

                                  \[\leadsto \color{blue}{1} \]
                                4. Step-by-step derivation
                                  1. Applied rewrites98.5%

                                    \[\leadsto \color{blue}{1} \]
                                  2. Step-by-step derivation
                                    1. Applied rewrites98.5%

                                      \[\leadsto \color{blue}{1} \]
                                    2. Step-by-step derivation
                                      1. Applied rewrites98.5%

                                        \[\leadsto \color{blue}{1} \]
                                      2. Step-by-step derivation
                                        1. Applied rewrites98.5%

                                          \[\leadsto \color{blue}{1} \]
                                      3. Recombined 2 regimes into one program.
                                      4. Add Preprocessing

                                      Alternative 7: 98.7% accurate, 0.8× speedup?

                                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{1}{x - 1} + \frac{x}{x + 1} \leq -1:\\ \;\;\;\;-1\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
                                      (FPCore (x)
                                       :precision binary64
                                       (if (<= (+ (/ 1.0 (- x 1.0)) (/ x (+ x 1.0))) -1.0) -1.0 1.0))
                                      double code(double x) {
                                      	double tmp;
                                      	if (((1.0 / (x - 1.0)) + (x / (x + 1.0))) <= -1.0) {
                                      		tmp = -1.0;
                                      	} else {
                                      		tmp = 1.0;
                                      	}
                                      	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) :: tmp
                                          if (((1.0d0 / (x - 1.0d0)) + (x / (x + 1.0d0))) <= (-1.0d0)) then
                                              tmp = -1.0d0
                                          else
                                              tmp = 1.0d0
                                          end if
                                          code = tmp
                                      end function
                                      
                                      public static double code(double x) {
                                      	double tmp;
                                      	if (((1.0 / (x - 1.0)) + (x / (x + 1.0))) <= -1.0) {
                                      		tmp = -1.0;
                                      	} else {
                                      		tmp = 1.0;
                                      	}
                                      	return tmp;
                                      }
                                      
                                      def code(x):
                                      	tmp = 0
                                      	if ((1.0 / (x - 1.0)) + (x / (x + 1.0))) <= -1.0:
                                      		tmp = -1.0
                                      	else:
                                      		tmp = 1.0
                                      	return tmp
                                      
                                      function code(x)
                                      	tmp = 0.0
                                      	if (Float64(Float64(1.0 / Float64(x - 1.0)) + Float64(x / Float64(x + 1.0))) <= -1.0)
                                      		tmp = -1.0;
                                      	else
                                      		tmp = 1.0;
                                      	end
                                      	return tmp
                                      end
                                      
                                      function tmp_2 = code(x)
                                      	tmp = 0.0;
                                      	if (((1.0 / (x - 1.0)) + (x / (x + 1.0))) <= -1.0)
                                      		tmp = -1.0;
                                      	else
                                      		tmp = 1.0;
                                      	end
                                      	tmp_2 = tmp;
                                      end
                                      
                                      code[x_] := If[LessEqual[N[(N[(1.0 / N[(x - 1.0), $MachinePrecision]), $MachinePrecision] + N[(x / N[(x + 1.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -1.0], -1.0, 1.0]
                                      
                                      \begin{array}{l}
                                      
                                      \\
                                      \begin{array}{l}
                                      \mathbf{if}\;\frac{1}{x - 1} + \frac{x}{x + 1} \leq -1:\\
                                      \;\;\;\;-1\\
                                      
                                      \mathbf{else}:\\
                                      \;\;\;\;1\\
                                      
                                      
                                      \end{array}
                                      \end{array}
                                      
                                      Derivation
                                      1. Split input into 2 regimes
                                      2. if (+.f64 (/.f64 #s(literal 1 binary64) (-.f64 x #s(literal 1 binary64))) (/.f64 x (+.f64 x #s(literal 1 binary64)))) < -1

                                        1. Initial program 100.0%

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

                                          \[\leadsto \color{blue}{-1} \]
                                        4. Step-by-step derivation
                                          1. Applied rewrites98.9%

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

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

                                          1. Initial program 100.0%

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

                                            \[\leadsto \color{blue}{1} \]
                                          4. Step-by-step derivation
                                            1. Applied rewrites98.5%

                                              \[\leadsto \color{blue}{1} \]
                                            2. Step-by-step derivation
                                              1. Applied rewrites98.5%

                                                \[\leadsto \color{blue}{1} \]
                                              2. Step-by-step derivation
                                                1. Applied rewrites98.5%

                                                  \[\leadsto \color{blue}{1} \]
                                                2. Step-by-step derivation
                                                  1. Applied rewrites98.5%

                                                    \[\leadsto \color{blue}{1} \]
                                                3. Recombined 2 regimes into one program.
                                                4. Add Preprocessing

                                                Alternative 8: 49.9% accurate, 32.0× 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 100.0%

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

                                                  \[\leadsto \color{blue}{-1} \]
                                                4. Step-by-step derivation
                                                  1. Applied rewrites49.9%

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

                                                  Reproduce

                                                  ?
                                                  herbie shell --seed 2025091 
                                                  (FPCore (x)
                                                    :name "Asymptote B"
                                                    :precision binary64
                                                    (+ (/ 1.0 (- x 1.0)) (/ x (+ x 1.0))))