Diagrams.Trail:splitAtParam from diagrams-lib-1.3.0.3, C

Percentage Accurate: 100.0% → 100.0%
Time: 8.1s
Alternatives: 10
Speedup: 1.0×

Specification

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

\\
\frac{x - y}{1 - y}
\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 10 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?

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

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

Alternative 1: 100.0% accurate, 1.0× speedup?

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

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

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

Alternative 2: 98.3% accurate, 0.2× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x - y}{1 - y}\\ t_1 := \frac{x}{1 - y}\\ \mathbf{if}\;t\_0 \leq -200000:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t\_0 \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(y, -1, x\right)\\ \mathbf{elif}\;t\_0 \leq 2:\\ \;\;\;\;\frac{y}{y + -1}\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (/ (- x y) (- 1.0 y))) (t_1 (/ x (- 1.0 y))))
   (if (<= t_0 -200000.0)
     t_1
     (if (<= t_0 0.01)
       (fma y -1.0 x)
       (if (<= t_0 2.0) (/ y (+ y -1.0)) t_1)))))
double code(double x, double y) {
	double t_0 = (x - y) / (1.0 - y);
	double t_1 = x / (1.0 - y);
	double tmp;
	if (t_0 <= -200000.0) {
		tmp = t_1;
	} else if (t_0 <= 0.01) {
		tmp = fma(y, -1.0, x);
	} else if (t_0 <= 2.0) {
		tmp = y / (y + -1.0);
	} else {
		tmp = t_1;
	}
	return tmp;
}
function code(x, y)
	t_0 = Float64(Float64(x - y) / Float64(1.0 - y))
	t_1 = Float64(x / Float64(1.0 - y))
	tmp = 0.0
	if (t_0 <= -200000.0)
		tmp = t_1;
	elseif (t_0 <= 0.01)
		tmp = fma(y, -1.0, x);
	elseif (t_0 <= 2.0)
		tmp = Float64(y / Float64(y + -1.0));
	else
		tmp = t_1;
	end
	return tmp
end
code[x_, y_] := Block[{t$95$0 = N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(x / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -200000.0], t$95$1, If[LessEqual[t$95$0, 0.01], N[(y * -1.0 + x), $MachinePrecision], If[LessEqual[t$95$0, 2.0], N[(y / N[(y + -1.0), $MachinePrecision]), $MachinePrecision], t$95$1]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{x - y}{1 - y}\\
t_1 := \frac{x}{1 - y}\\
\mathbf{if}\;t\_0 \leq -200000:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;t\_0 \leq 0.01:\\
\;\;\;\;\mathsf{fma}\left(y, -1, x\right)\\

\mathbf{elif}\;t\_0 \leq 2:\\
\;\;\;\;\frac{y}{y + -1}\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)) < -2e5 or 2 < (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y))

    1. Initial program 100.0%

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

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

        \[\leadsto \color{blue}{\frac{x}{1 - y}} \]
      2. lower--.f6498.9

        \[\leadsto \frac{x}{\color{blue}{1 - y}} \]
    5. Applied rewrites98.9%

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

    if -2e5 < (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)) < 0.0100000000000000002

    1. Initial program 99.9%

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

      \[\leadsto \color{blue}{1} \]
    4. Step-by-step derivation
      1. Applied rewrites4.3%

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

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

          \[\leadsto \color{blue}{-1 \cdot \left(y \cdot \left(1 + -1 \cdot x\right)\right) + x} \]
        2. mul-1-negN/A

          \[\leadsto -1 \cdot \left(y \cdot \left(1 + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right) + x \]
        3. sub-negN/A

          \[\leadsto -1 \cdot \left(y \cdot \color{blue}{\left(1 - x\right)}\right) + x \]
        4. mul-1-negN/A

          \[\leadsto \color{blue}{\left(\mathsf{neg}\left(y \cdot \left(1 - x\right)\right)\right)} + x \]
        5. distribute-rgt-neg-inN/A

          \[\leadsto \color{blue}{y \cdot \left(\mathsf{neg}\left(\left(1 - x\right)\right)\right)} + x \]
        6. mul-1-negN/A

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

          \[\leadsto \color{blue}{\mathsf{fma}\left(y, -1 \cdot \left(1 - x\right), x\right)} \]
        8. sub-negN/A

          \[\leadsto \mathsf{fma}\left(y, -1 \cdot \color{blue}{\left(1 + \left(\mathsf{neg}\left(x\right)\right)\right)}, x\right) \]
        9. mul-1-negN/A

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

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

          \[\leadsto \mathsf{fma}\left(y, \color{blue}{-1} + -1 \cdot \left(-1 \cdot x\right), x\right) \]
        12. neg-mul-1N/A

          \[\leadsto \mathsf{fma}\left(y, -1 + \color{blue}{\left(\mathsf{neg}\left(-1 \cdot x\right)\right)}, x\right) \]
        13. mul-1-negN/A

          \[\leadsto \mathsf{fma}\left(y, -1 + \left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right), x\right) \]
        14. remove-double-negN/A

          \[\leadsto \mathsf{fma}\left(y, -1 + \color{blue}{x}, x\right) \]
        15. lower-+.f6497.5

          \[\leadsto \mathsf{fma}\left(y, \color{blue}{-1 + x}, x\right) \]
      4. Applied rewrites97.5%

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

        \[\leadsto \mathsf{fma}\left(y, -1, x\right) \]
      6. Step-by-step derivation
        1. Applied rewrites97.5%

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

        if 0.0100000000000000002 < (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)) < 2

        1. Initial program 100.0%

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

          \[\leadsto \color{blue}{-1 \cdot \frac{y}{1 - y}} \]
        4. Step-by-step derivation
          1. mul-1-negN/A

            \[\leadsto \color{blue}{\mathsf{neg}\left(\frac{y}{1 - y}\right)} \]
          2. distribute-neg-frac2N/A

            \[\leadsto \color{blue}{\frac{y}{\mathsf{neg}\left(\left(1 - y\right)\right)}} \]
          3. lower-/.f64N/A

            \[\leadsto \color{blue}{\frac{y}{\mathsf{neg}\left(\left(1 - y\right)\right)}} \]
          4. neg-sub0N/A

            \[\leadsto \frac{y}{\color{blue}{0 - \left(1 - y\right)}} \]
          5. associate--r-N/A

            \[\leadsto \frac{y}{\color{blue}{\left(0 - 1\right) + y}} \]
          6. metadata-evalN/A

            \[\leadsto \frac{y}{\color{blue}{-1} + y} \]
          7. lower-+.f6494.6

            \[\leadsto \frac{y}{\color{blue}{-1 + y}} \]
        5. Applied rewrites94.6%

          \[\leadsto \color{blue}{\frac{y}{-1 + y}} \]
      7. Recombined 3 regimes into one program.
      8. Final simplification96.8%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x - y}{1 - y} \leq -200000:\\ \;\;\;\;\frac{x}{1 - y}\\ \mathbf{elif}\;\frac{x - y}{1 - y} \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(y, -1, x\right)\\ \mathbf{elif}\;\frac{x - y}{1 - y} \leq 2:\\ \;\;\;\;\frac{y}{y + -1}\\ \mathbf{else}:\\ \;\;\;\;\frac{x}{1 - y}\\ \end{array} \]
      9. Add Preprocessing

      Alternative 3: 97.6% accurate, 0.2× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x - y}{1 - y}\\ t_1 := \frac{x}{1 - y}\\ \mathbf{if}\;t\_0 \leq -200000:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t\_0 \leq 0.01:\\ \;\;\;\;\mathsf{fma}\left(y, -1, x\right)\\ \mathbf{elif}\;t\_0 \leq 2:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
      (FPCore (x y)
       :precision binary64
       (let* ((t_0 (/ (- x y) (- 1.0 y))) (t_1 (/ x (- 1.0 y))))
         (if (<= t_0 -200000.0)
           t_1
           (if (<= t_0 0.01) (fma y -1.0 x) (if (<= t_0 2.0) 1.0 t_1)))))
      double code(double x, double y) {
      	double t_0 = (x - y) / (1.0 - y);
      	double t_1 = x / (1.0 - y);
      	double tmp;
      	if (t_0 <= -200000.0) {
      		tmp = t_1;
      	} else if (t_0 <= 0.01) {
      		tmp = fma(y, -1.0, x);
      	} else if (t_0 <= 2.0) {
      		tmp = 1.0;
      	} else {
      		tmp = t_1;
      	}
      	return tmp;
      }
      
      function code(x, y)
      	t_0 = Float64(Float64(x - y) / Float64(1.0 - y))
      	t_1 = Float64(x / Float64(1.0 - y))
      	tmp = 0.0
      	if (t_0 <= -200000.0)
      		tmp = t_1;
      	elseif (t_0 <= 0.01)
      		tmp = fma(y, -1.0, x);
      	elseif (t_0 <= 2.0)
      		tmp = 1.0;
      	else
      		tmp = t_1;
      	end
      	return tmp
      end
      
      code[x_, y_] := Block[{t$95$0 = N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(x / N[(1.0 - y), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, -200000.0], t$95$1, If[LessEqual[t$95$0, 0.01], N[(y * -1.0 + x), $MachinePrecision], If[LessEqual[t$95$0, 2.0], 1.0, t$95$1]]]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_0 := \frac{x - y}{1 - y}\\
      t_1 := \frac{x}{1 - y}\\
      \mathbf{if}\;t\_0 \leq -200000:\\
      \;\;\;\;t\_1\\
      
      \mathbf{elif}\;t\_0 \leq 0.01:\\
      \;\;\;\;\mathsf{fma}\left(y, -1, x\right)\\
      
      \mathbf{elif}\;t\_0 \leq 2:\\
      \;\;\;\;1\\
      
      \mathbf{else}:\\
      \;\;\;\;t\_1\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 3 regimes
      2. if (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)) < -2e5 or 2 < (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y))

        1. Initial program 100.0%

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

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

            \[\leadsto \color{blue}{\frac{x}{1 - y}} \]
          2. lower--.f6498.9

            \[\leadsto \frac{x}{\color{blue}{1 - y}} \]
        5. Applied rewrites98.9%

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

        if -2e5 < (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)) < 0.0100000000000000002

        1. Initial program 99.9%

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

          \[\leadsto \color{blue}{1} \]
        4. Step-by-step derivation
          1. Applied rewrites4.3%

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

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

              \[\leadsto \color{blue}{-1 \cdot \left(y \cdot \left(1 + -1 \cdot x\right)\right) + x} \]
            2. mul-1-negN/A

              \[\leadsto -1 \cdot \left(y \cdot \left(1 + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right) + x \]
            3. sub-negN/A

              \[\leadsto -1 \cdot \left(y \cdot \color{blue}{\left(1 - x\right)}\right) + x \]
            4. mul-1-negN/A

              \[\leadsto \color{blue}{\left(\mathsf{neg}\left(y \cdot \left(1 - x\right)\right)\right)} + x \]
            5. distribute-rgt-neg-inN/A

              \[\leadsto \color{blue}{y \cdot \left(\mathsf{neg}\left(\left(1 - x\right)\right)\right)} + x \]
            6. mul-1-negN/A

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

              \[\leadsto \color{blue}{\mathsf{fma}\left(y, -1 \cdot \left(1 - x\right), x\right)} \]
            8. sub-negN/A

              \[\leadsto \mathsf{fma}\left(y, -1 \cdot \color{blue}{\left(1 + \left(\mathsf{neg}\left(x\right)\right)\right)}, x\right) \]
            9. mul-1-negN/A

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

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

              \[\leadsto \mathsf{fma}\left(y, \color{blue}{-1} + -1 \cdot \left(-1 \cdot x\right), x\right) \]
            12. neg-mul-1N/A

              \[\leadsto \mathsf{fma}\left(y, -1 + \color{blue}{\left(\mathsf{neg}\left(-1 \cdot x\right)\right)}, x\right) \]
            13. mul-1-negN/A

              \[\leadsto \mathsf{fma}\left(y, -1 + \left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right), x\right) \]
            14. remove-double-negN/A

              \[\leadsto \mathsf{fma}\left(y, -1 + \color{blue}{x}, x\right) \]
            15. lower-+.f6497.5

              \[\leadsto \mathsf{fma}\left(y, \color{blue}{-1 + x}, x\right) \]
          4. Applied rewrites97.5%

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

            \[\leadsto \mathsf{fma}\left(y, -1, x\right) \]
          6. Step-by-step derivation
            1. Applied rewrites97.5%

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

            if 0.0100000000000000002 < (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)) < 2

            1. Initial program 100.0%

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

              \[\leadsto \color{blue}{1} \]
            4. Step-by-step derivation
              1. Applied rewrites93.7%

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

            Alternative 4: 98.2% accurate, 0.6× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 + \frac{1 - x}{y}\\ \mathbf{if}\;y \leq -1.05:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;\mathsf{fma}\left(y, x, x\right) - y\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
            (FPCore (x y)
             :precision binary64
             (let* ((t_0 (+ 1.0 (/ (- 1.0 x) y))))
               (if (<= y -1.05) t_0 (if (<= y 1.0) (- (fma y x x) y) t_0))))
            double code(double x, double y) {
            	double t_0 = 1.0 + ((1.0 - x) / y);
            	double tmp;
            	if (y <= -1.05) {
            		tmp = t_0;
            	} else if (y <= 1.0) {
            		tmp = fma(y, x, x) - y;
            	} else {
            		tmp = t_0;
            	}
            	return tmp;
            }
            
            function code(x, y)
            	t_0 = Float64(1.0 + Float64(Float64(1.0 - x) / y))
            	tmp = 0.0
            	if (y <= -1.05)
            		tmp = t_0;
            	elseif (y <= 1.0)
            		tmp = Float64(fma(y, x, x) - y);
            	else
            		tmp = t_0;
            	end
            	return tmp
            end
            
            code[x_, y_] := Block[{t$95$0 = N[(1.0 + N[(N[(1.0 - x), $MachinePrecision] / y), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y, -1.05], t$95$0, If[LessEqual[y, 1.0], N[(N[(y * x + x), $MachinePrecision] - y), $MachinePrecision], t$95$0]]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            t_0 := 1 + \frac{1 - x}{y}\\
            \mathbf{if}\;y \leq -1.05:\\
            \;\;\;\;t\_0\\
            
            \mathbf{elif}\;y \leq 1:\\
            \;\;\;\;\mathsf{fma}\left(y, x, x\right) - y\\
            
            \mathbf{else}:\\
            \;\;\;\;t\_0\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 2 regimes
            2. if y < -1.05000000000000004 or 1 < y

              1. Initial program 100.0%

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

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

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

                  \[\leadsto 1 + \left(\frac{1}{y} + \color{blue}{\left(\mathsf{neg}\left(\frac{x}{y}\right)\right)}\right) \]
                3. sub-negN/A

                  \[\leadsto 1 + \color{blue}{\left(\frac{1}{y} - \frac{x}{y}\right)} \]
                4. div-subN/A

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

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

                  \[\leadsto 1 + \frac{\color{blue}{1 + \left(\mathsf{neg}\left(x\right)\right)}}{y} \]
                7. mul-1-negN/A

                  \[\leadsto 1 + \frac{1 + \color{blue}{-1 \cdot x}}{y} \]
                8. lower-/.f64N/A

                  \[\leadsto 1 + \color{blue}{\frac{1 + -1 \cdot x}{y}} \]
                9. mul-1-negN/A

                  \[\leadsto 1 + \frac{1 + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}}{y} \]
                10. sub-negN/A

                  \[\leadsto 1 + \frac{\color{blue}{1 - x}}{y} \]
                11. lower--.f6499.4

                  \[\leadsto 1 + \frac{\color{blue}{1 - x}}{y} \]
              5. Applied rewrites99.4%

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

              if -1.05000000000000004 < y < 1

              1. Initial program 100.0%

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

                \[\leadsto \color{blue}{x + -1 \cdot \left(y \cdot \left(1 + -1 \cdot x\right)\right)} \]
              4. Step-by-step derivation
                1. mul-1-negN/A

                  \[\leadsto x + \color{blue}{\left(\mathsf{neg}\left(y \cdot \left(1 + -1 \cdot x\right)\right)\right)} \]
                2. unsub-negN/A

                  \[\leadsto \color{blue}{x - y \cdot \left(1 + -1 \cdot x\right)} \]
                3. mul-1-negN/A

                  \[\leadsto x - y \cdot \left(1 + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right) \]
                4. +-commutativeN/A

                  \[\leadsto x - y \cdot \color{blue}{\left(\left(\mathsf{neg}\left(x\right)\right) + 1\right)} \]
                5. distribute-lft-inN/A

                  \[\leadsto x - \color{blue}{\left(y \cdot \left(\mathsf{neg}\left(x\right)\right) + y \cdot 1\right)} \]
                6. *-rgt-identityN/A

                  \[\leadsto x - \left(y \cdot \left(\mathsf{neg}\left(x\right)\right) + \color{blue}{y}\right) \]
                7. associate--r+N/A

                  \[\leadsto \color{blue}{\left(x - y \cdot \left(\mathsf{neg}\left(x\right)\right)\right) - y} \]
                8. *-commutativeN/A

                  \[\leadsto \left(x - \color{blue}{\left(\mathsf{neg}\left(x\right)\right) \cdot y}\right) - y \]
                9. cancel-sign-subN/A

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

                  \[\leadsto \color{blue}{\left(x \cdot y + x\right)} - y \]
                11. remove-double-negN/A

                  \[\leadsto \left(x \cdot y + \color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right)}\right) - y \]
                12. sub-negN/A

                  \[\leadsto \color{blue}{\left(x \cdot y - \left(\mathsf{neg}\left(x\right)\right)\right)} - y \]
                13. lower--.f64N/A

                  \[\leadsto \color{blue}{\left(x \cdot y - \left(\mathsf{neg}\left(x\right)\right)\right) - y} \]
                14. sub-negN/A

                  \[\leadsto \color{blue}{\left(x \cdot y + \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right)\right)} - y \]
                15. remove-double-negN/A

                  \[\leadsto \left(x \cdot y + \color{blue}{x}\right) - y \]
                16. *-rgt-identityN/A

                  \[\leadsto \left(x \cdot y + \color{blue}{x \cdot 1}\right) - y \]
                17. distribute-lft-outN/A

                  \[\leadsto \color{blue}{x \cdot \left(y + 1\right)} - y \]
                18. distribute-rgt-outN/A

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

                  \[\leadsto \left(y \cdot x + \color{blue}{x}\right) - y \]
                20. lower-fma.f6498.1

                  \[\leadsto \color{blue}{\mathsf{fma}\left(y, x, x\right)} - y \]
              5. Applied rewrites98.1%

                \[\leadsto \color{blue}{\mathsf{fma}\left(y, x, x\right) - y} \]
            3. Recombined 2 regimes into one program.
            4. Add Preprocessing

            Alternative 5: 97.9% accurate, 0.6× speedup?

            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -0.82:\\ \;\;\;\;1 + \frac{-x}{y}\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;\mathsf{fma}\left(y, x, x\right) - y\\ \mathbf{else}:\\ \;\;\;\;\frac{x - y}{-y}\\ \end{array} \end{array} \]
            (FPCore (x y)
             :precision binary64
             (if (<= y -0.82)
               (+ 1.0 (/ (- x) y))
               (if (<= y 1.0) (- (fma y x x) y) (/ (- x y) (- y)))))
            double code(double x, double y) {
            	double tmp;
            	if (y <= -0.82) {
            		tmp = 1.0 + (-x / y);
            	} else if (y <= 1.0) {
            		tmp = fma(y, x, x) - y;
            	} else {
            		tmp = (x - y) / -y;
            	}
            	return tmp;
            }
            
            function code(x, y)
            	tmp = 0.0
            	if (y <= -0.82)
            		tmp = Float64(1.0 + Float64(Float64(-x) / y));
            	elseif (y <= 1.0)
            		tmp = Float64(fma(y, x, x) - y);
            	else
            		tmp = Float64(Float64(x - y) / Float64(-y));
            	end
            	return tmp
            end
            
            code[x_, y_] := If[LessEqual[y, -0.82], N[(1.0 + N[((-x) / y), $MachinePrecision]), $MachinePrecision], If[LessEqual[y, 1.0], N[(N[(y * x + x), $MachinePrecision] - y), $MachinePrecision], N[(N[(x - y), $MachinePrecision] / (-y)), $MachinePrecision]]]
            
            \begin{array}{l}
            
            \\
            \begin{array}{l}
            \mathbf{if}\;y \leq -0.82:\\
            \;\;\;\;1 + \frac{-x}{y}\\
            
            \mathbf{elif}\;y \leq 1:\\
            \;\;\;\;\mathsf{fma}\left(y, x, x\right) - y\\
            
            \mathbf{else}:\\
            \;\;\;\;\frac{x - y}{-y}\\
            
            
            \end{array}
            \end{array}
            
            Derivation
            1. Split input into 3 regimes
            2. if y < -0.819999999999999951

              1. Initial program 99.9%

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

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

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

                  \[\leadsto 1 + \left(\frac{1}{y} + \color{blue}{\left(\mathsf{neg}\left(\frac{x}{y}\right)\right)}\right) \]
                3. sub-negN/A

                  \[\leadsto 1 + \color{blue}{\left(\frac{1}{y} - \frac{x}{y}\right)} \]
                4. div-subN/A

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

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

                  \[\leadsto 1 + \frac{\color{blue}{1 + \left(\mathsf{neg}\left(x\right)\right)}}{y} \]
                7. mul-1-negN/A

                  \[\leadsto 1 + \frac{1 + \color{blue}{-1 \cdot x}}{y} \]
                8. lower-/.f64N/A

                  \[\leadsto 1 + \color{blue}{\frac{1 + -1 \cdot x}{y}} \]
                9. mul-1-negN/A

                  \[\leadsto 1 + \frac{1 + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}}{y} \]
                10. sub-negN/A

                  \[\leadsto 1 + \frac{\color{blue}{1 - x}}{y} \]
                11. lower--.f6497.9

                  \[\leadsto 1 + \frac{\color{blue}{1 - x}}{y} \]
              5. Applied rewrites97.9%

                \[\leadsto \color{blue}{1 + \frac{1 - x}{y}} \]
              6. Taylor expanded in x around inf

                \[\leadsto 1 + \frac{-1 \cdot x}{y} \]
              7. Step-by-step derivation
                1. Applied rewrites97.9%

                  \[\leadsto 1 + \frac{-x}{y} \]

                if -0.819999999999999951 < y < 1

                1. Initial program 100.0%

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

                  \[\leadsto \color{blue}{x + -1 \cdot \left(y \cdot \left(1 + -1 \cdot x\right)\right)} \]
                4. Step-by-step derivation
                  1. mul-1-negN/A

                    \[\leadsto x + \color{blue}{\left(\mathsf{neg}\left(y \cdot \left(1 + -1 \cdot x\right)\right)\right)} \]
                  2. unsub-negN/A

                    \[\leadsto \color{blue}{x - y \cdot \left(1 + -1 \cdot x\right)} \]
                  3. mul-1-negN/A

                    \[\leadsto x - y \cdot \left(1 + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right) \]
                  4. +-commutativeN/A

                    \[\leadsto x - y \cdot \color{blue}{\left(\left(\mathsf{neg}\left(x\right)\right) + 1\right)} \]
                  5. distribute-lft-inN/A

                    \[\leadsto x - \color{blue}{\left(y \cdot \left(\mathsf{neg}\left(x\right)\right) + y \cdot 1\right)} \]
                  6. *-rgt-identityN/A

                    \[\leadsto x - \left(y \cdot \left(\mathsf{neg}\left(x\right)\right) + \color{blue}{y}\right) \]
                  7. associate--r+N/A

                    \[\leadsto \color{blue}{\left(x - y \cdot \left(\mathsf{neg}\left(x\right)\right)\right) - y} \]
                  8. *-commutativeN/A

                    \[\leadsto \left(x - \color{blue}{\left(\mathsf{neg}\left(x\right)\right) \cdot y}\right) - y \]
                  9. cancel-sign-subN/A

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

                    \[\leadsto \color{blue}{\left(x \cdot y + x\right)} - y \]
                  11. remove-double-negN/A

                    \[\leadsto \left(x \cdot y + \color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right)}\right) - y \]
                  12. sub-negN/A

                    \[\leadsto \color{blue}{\left(x \cdot y - \left(\mathsf{neg}\left(x\right)\right)\right)} - y \]
                  13. lower--.f64N/A

                    \[\leadsto \color{blue}{\left(x \cdot y - \left(\mathsf{neg}\left(x\right)\right)\right) - y} \]
                  14. sub-negN/A

                    \[\leadsto \color{blue}{\left(x \cdot y + \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right)\right)} - y \]
                  15. remove-double-negN/A

                    \[\leadsto \left(x \cdot y + \color{blue}{x}\right) - y \]
                  16. *-rgt-identityN/A

                    \[\leadsto \left(x \cdot y + \color{blue}{x \cdot 1}\right) - y \]
                  17. distribute-lft-outN/A

                    \[\leadsto \color{blue}{x \cdot \left(y + 1\right)} - y \]
                  18. distribute-rgt-outN/A

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

                    \[\leadsto \left(y \cdot x + \color{blue}{x}\right) - y \]
                  20. lower-fma.f6498.8

                    \[\leadsto \color{blue}{\mathsf{fma}\left(y, x, x\right)} - y \]
                5. Applied rewrites98.8%

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

                if 1 < y

                1. Initial program 100.0%

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

                  \[\leadsto \frac{x - y}{\color{blue}{-1 \cdot y}} \]
                4. Step-by-step derivation
                  1. mul-1-negN/A

                    \[\leadsto \frac{x - y}{\color{blue}{\mathsf{neg}\left(y\right)}} \]
                  2. lower-neg.f6499.2

                    \[\leadsto \frac{x - y}{\color{blue}{-y}} \]
                5. Applied rewrites99.2%

                  \[\leadsto \frac{x - y}{\color{blue}{-y}} \]
              8. Recombined 3 regimes into one program.
              9. Add Preprocessing

              Alternative 6: 97.9% accurate, 0.6× speedup?

              \[\begin{array}{l} \\ \begin{array}{l} t_0 := 1 + \frac{-x}{y}\\ \mathbf{if}\;y \leq -0.82:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;\mathsf{fma}\left(y, x, x\right) - y\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
              (FPCore (x y)
               :precision binary64
               (let* ((t_0 (+ 1.0 (/ (- x) y))))
                 (if (<= y -0.82) t_0 (if (<= y 1.0) (- (fma y x x) y) t_0))))
              double code(double x, double y) {
              	double t_0 = 1.0 + (-x / y);
              	double tmp;
              	if (y <= -0.82) {
              		tmp = t_0;
              	} else if (y <= 1.0) {
              		tmp = fma(y, x, x) - y;
              	} else {
              		tmp = t_0;
              	}
              	return tmp;
              }
              
              function code(x, y)
              	t_0 = Float64(1.0 + Float64(Float64(-x) / y))
              	tmp = 0.0
              	if (y <= -0.82)
              		tmp = t_0;
              	elseif (y <= 1.0)
              		tmp = Float64(fma(y, x, x) - y);
              	else
              		tmp = t_0;
              	end
              	return tmp
              end
              
              code[x_, y_] := Block[{t$95$0 = N[(1.0 + N[((-x) / y), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y, -0.82], t$95$0, If[LessEqual[y, 1.0], N[(N[(y * x + x), $MachinePrecision] - y), $MachinePrecision], t$95$0]]]
              
              \begin{array}{l}
              
              \\
              \begin{array}{l}
              t_0 := 1 + \frac{-x}{y}\\
              \mathbf{if}\;y \leq -0.82:\\
              \;\;\;\;t\_0\\
              
              \mathbf{elif}\;y \leq 1:\\
              \;\;\;\;\mathsf{fma}\left(y, x, x\right) - y\\
              
              \mathbf{else}:\\
              \;\;\;\;t\_0\\
              
              
              \end{array}
              \end{array}
              
              Derivation
              1. Split input into 2 regimes
              2. if y < -0.819999999999999951 or 1 < y

                1. Initial program 100.0%

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

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

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

                    \[\leadsto 1 + \left(\frac{1}{y} + \color{blue}{\left(\mathsf{neg}\left(\frac{x}{y}\right)\right)}\right) \]
                  3. sub-negN/A

                    \[\leadsto 1 + \color{blue}{\left(\frac{1}{y} - \frac{x}{y}\right)} \]
                  4. div-subN/A

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

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

                    \[\leadsto 1 + \frac{\color{blue}{1 + \left(\mathsf{neg}\left(x\right)\right)}}{y} \]
                  7. mul-1-negN/A

                    \[\leadsto 1 + \frac{1 + \color{blue}{-1 \cdot x}}{y} \]
                  8. lower-/.f64N/A

                    \[\leadsto 1 + \color{blue}{\frac{1 + -1 \cdot x}{y}} \]
                  9. mul-1-negN/A

                    \[\leadsto 1 + \frac{1 + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}}{y} \]
                  10. sub-negN/A

                    \[\leadsto 1 + \frac{\color{blue}{1 - x}}{y} \]
                  11. lower--.f6498.8

                    \[\leadsto 1 + \frac{\color{blue}{1 - x}}{y} \]
                5. Applied rewrites98.8%

                  \[\leadsto \color{blue}{1 + \frac{1 - x}{y}} \]
                6. Taylor expanded in x around inf

                  \[\leadsto 1 + \frac{-1 \cdot x}{y} \]
                7. Step-by-step derivation
                  1. Applied rewrites98.6%

                    \[\leadsto 1 + \frac{-x}{y} \]

                  if -0.819999999999999951 < y < 1

                  1. Initial program 100.0%

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

                    \[\leadsto \color{blue}{x + -1 \cdot \left(y \cdot \left(1 + -1 \cdot x\right)\right)} \]
                  4. Step-by-step derivation
                    1. mul-1-negN/A

                      \[\leadsto x + \color{blue}{\left(\mathsf{neg}\left(y \cdot \left(1 + -1 \cdot x\right)\right)\right)} \]
                    2. unsub-negN/A

                      \[\leadsto \color{blue}{x - y \cdot \left(1 + -1 \cdot x\right)} \]
                    3. mul-1-negN/A

                      \[\leadsto x - y \cdot \left(1 + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right) \]
                    4. +-commutativeN/A

                      \[\leadsto x - y \cdot \color{blue}{\left(\left(\mathsf{neg}\left(x\right)\right) + 1\right)} \]
                    5. distribute-lft-inN/A

                      \[\leadsto x - \color{blue}{\left(y \cdot \left(\mathsf{neg}\left(x\right)\right) + y \cdot 1\right)} \]
                    6. *-rgt-identityN/A

                      \[\leadsto x - \left(y \cdot \left(\mathsf{neg}\left(x\right)\right) + \color{blue}{y}\right) \]
                    7. associate--r+N/A

                      \[\leadsto \color{blue}{\left(x - y \cdot \left(\mathsf{neg}\left(x\right)\right)\right) - y} \]
                    8. *-commutativeN/A

                      \[\leadsto \left(x - \color{blue}{\left(\mathsf{neg}\left(x\right)\right) \cdot y}\right) - y \]
                    9. cancel-sign-subN/A

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

                      \[\leadsto \color{blue}{\left(x \cdot y + x\right)} - y \]
                    11. remove-double-negN/A

                      \[\leadsto \left(x \cdot y + \color{blue}{\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right)}\right) - y \]
                    12. sub-negN/A

                      \[\leadsto \color{blue}{\left(x \cdot y - \left(\mathsf{neg}\left(x\right)\right)\right)} - y \]
                    13. lower--.f64N/A

                      \[\leadsto \color{blue}{\left(x \cdot y - \left(\mathsf{neg}\left(x\right)\right)\right) - y} \]
                    14. sub-negN/A

                      \[\leadsto \color{blue}{\left(x \cdot y + \left(\mathsf{neg}\left(\left(\mathsf{neg}\left(x\right)\right)\right)\right)\right)} - y \]
                    15. remove-double-negN/A

                      \[\leadsto \left(x \cdot y + \color{blue}{x}\right) - y \]
                    16. *-rgt-identityN/A

                      \[\leadsto \left(x \cdot y + \color{blue}{x \cdot 1}\right) - y \]
                    17. distribute-lft-outN/A

                      \[\leadsto \color{blue}{x \cdot \left(y + 1\right)} - y \]
                    18. distribute-rgt-outN/A

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

                      \[\leadsto \left(y \cdot x + \color{blue}{x}\right) - y \]
                    20. lower-fma.f6498.8

                      \[\leadsto \color{blue}{\mathsf{fma}\left(y, x, x\right)} - y \]
                  5. Applied rewrites98.8%

                    \[\leadsto \color{blue}{\mathsf{fma}\left(y, x, x\right) - y} \]
                8. Recombined 2 regimes into one program.
                9. Add Preprocessing

                Alternative 7: 49.1% accurate, 0.7× speedup?

                \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{x - y}{1 - y} \leq 10^{-5}:\\ \;\;\;\;-y\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
                (FPCore (x y)
                 :precision binary64
                 (if (<= (/ (- x y) (- 1.0 y)) 1e-5) (- y) 1.0))
                double code(double x, double y) {
                	double tmp;
                	if (((x - y) / (1.0 - y)) <= 1e-5) {
                		tmp = -y;
                	} else {
                		tmp = 1.0;
                	}
                	return tmp;
                }
                
                real(8) function code(x, y)
                    real(8), intent (in) :: x
                    real(8), intent (in) :: y
                    real(8) :: tmp
                    if (((x - y) / (1.0d0 - y)) <= 1d-5) then
                        tmp = -y
                    else
                        tmp = 1.0d0
                    end if
                    code = tmp
                end function
                
                public static double code(double x, double y) {
                	double tmp;
                	if (((x - y) / (1.0 - y)) <= 1e-5) {
                		tmp = -y;
                	} else {
                		tmp = 1.0;
                	}
                	return tmp;
                }
                
                def code(x, y):
                	tmp = 0
                	if ((x - y) / (1.0 - y)) <= 1e-5:
                		tmp = -y
                	else:
                		tmp = 1.0
                	return tmp
                
                function code(x, y)
                	tmp = 0.0
                	if (Float64(Float64(x - y) / Float64(1.0 - y)) <= 1e-5)
                		tmp = Float64(-y);
                	else
                		tmp = 1.0;
                	end
                	return tmp
                end
                
                function tmp_2 = code(x, y)
                	tmp = 0.0;
                	if (((x - y) / (1.0 - y)) <= 1e-5)
                		tmp = -y;
                	else
                		tmp = 1.0;
                	end
                	tmp_2 = tmp;
                end
                
                code[x_, y_] := If[LessEqual[N[(N[(x - y), $MachinePrecision] / N[(1.0 - y), $MachinePrecision]), $MachinePrecision], 1e-5], (-y), 1.0]
                
                \begin{array}{l}
                
                \\
                \begin{array}{l}
                \mathbf{if}\;\frac{x - y}{1 - y} \leq 10^{-5}:\\
                \;\;\;\;-y\\
                
                \mathbf{else}:\\
                \;\;\;\;1\\
                
                
                \end{array}
                \end{array}
                
                Derivation
                1. Split input into 2 regimes
                2. if (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y)) < 1.00000000000000008e-5

                  1. Initial program 100.0%

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

                    \[\leadsto \color{blue}{1} \]
                  4. Step-by-step derivation
                    1. Applied rewrites2.9%

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

                      \[\leadsto \color{blue}{-1 \cdot \frac{y}{1 - y}} \]
                    3. Step-by-step derivation
                      1. associate-*r/N/A

                        \[\leadsto \color{blue}{\frac{-1 \cdot y}{1 - y}} \]
                      2. sub-negN/A

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

                        \[\leadsto \frac{-1 \cdot y}{\color{blue}{\left(\mathsf{neg}\left(-1\right)\right)} + \left(\mathsf{neg}\left(y\right)\right)} \]
                      4. distribute-neg-inN/A

                        \[\leadsto \frac{-1 \cdot y}{\color{blue}{\mathsf{neg}\left(\left(-1 + y\right)\right)}} \]
                      5. +-commutativeN/A

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

                        \[\leadsto \frac{-1 \cdot y}{\mathsf{neg}\left(\left(y + \color{blue}{\left(\mathsf{neg}\left(1\right)\right)}\right)\right)} \]
                      7. sub-negN/A

                        \[\leadsto \frac{-1 \cdot y}{\mathsf{neg}\left(\color{blue}{\left(y - 1\right)}\right)} \]
                      8. distribute-frac-neg2N/A

                        \[\leadsto \color{blue}{\mathsf{neg}\left(\frac{-1 \cdot y}{y - 1}\right)} \]
                      9. distribute-frac-negN/A

                        \[\leadsto \color{blue}{\frac{\mathsf{neg}\left(-1 \cdot y\right)}{y - 1}} \]
                      10. mul-1-negN/A

                        \[\leadsto \frac{\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(y\right)\right)}\right)}{y - 1} \]
                      11. remove-double-negN/A

                        \[\leadsto \frac{\color{blue}{y}}{y - 1} \]
                      12. lower-/.f64N/A

                        \[\leadsto \color{blue}{\frac{y}{y - 1}} \]
                      13. sub-negN/A

                        \[\leadsto \frac{y}{\color{blue}{y + \left(\mathsf{neg}\left(1\right)\right)}} \]
                      14. metadata-evalN/A

                        \[\leadsto \frac{y}{y + \color{blue}{-1}} \]
                      15. lower-+.f6431.9

                        \[\leadsto \frac{y}{\color{blue}{y + -1}} \]
                    4. Applied rewrites31.9%

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

                      \[\leadsto -1 \cdot \color{blue}{y} \]
                    6. Step-by-step derivation
                      1. Applied rewrites30.7%

                        \[\leadsto -y \]

                      if 1.00000000000000008e-5 < (/.f64 (-.f64 x y) (-.f64 #s(literal 1 binary64) y))

                      1. Initial program 100.0%

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

                        \[\leadsto \color{blue}{1} \]
                      4. Step-by-step derivation
                        1. Applied rewrites67.0%

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

                      Alternative 8: 85.2% accurate, 0.9× speedup?

                      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -2.2 \cdot 10^{+15}:\\ \;\;\;\;1\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;\mathsf{fma}\left(y, -1, x\right)\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
                      (FPCore (x y)
                       :precision binary64
                       (if (<= y -2.2e+15) 1.0 (if (<= y 1.0) (fma y -1.0 x) 1.0)))
                      double code(double x, double y) {
                      	double tmp;
                      	if (y <= -2.2e+15) {
                      		tmp = 1.0;
                      	} else if (y <= 1.0) {
                      		tmp = fma(y, -1.0, x);
                      	} else {
                      		tmp = 1.0;
                      	}
                      	return tmp;
                      }
                      
                      function code(x, y)
                      	tmp = 0.0
                      	if (y <= -2.2e+15)
                      		tmp = 1.0;
                      	elseif (y <= 1.0)
                      		tmp = fma(y, -1.0, x);
                      	else
                      		tmp = 1.0;
                      	end
                      	return tmp
                      end
                      
                      code[x_, y_] := If[LessEqual[y, -2.2e+15], 1.0, If[LessEqual[y, 1.0], N[(y * -1.0 + x), $MachinePrecision], 1.0]]
                      
                      \begin{array}{l}
                      
                      \\
                      \begin{array}{l}
                      \mathbf{if}\;y \leq -2.2 \cdot 10^{+15}:\\
                      \;\;\;\;1\\
                      
                      \mathbf{elif}\;y \leq 1:\\
                      \;\;\;\;\mathsf{fma}\left(y, -1, x\right)\\
                      
                      \mathbf{else}:\\
                      \;\;\;\;1\\
                      
                      
                      \end{array}
                      \end{array}
                      
                      Derivation
                      1. Split input into 2 regimes
                      2. if y < -2.2e15 or 1 < y

                        1. Initial program 100.0%

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

                          \[\leadsto \color{blue}{1} \]
                        4. Step-by-step derivation
                          1. Applied rewrites78.9%

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

                          if -2.2e15 < y < 1

                          1. Initial program 100.0%

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

                            \[\leadsto \color{blue}{1} \]
                          4. Step-by-step derivation
                            1. Applied rewrites3.9%

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

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

                                \[\leadsto \color{blue}{-1 \cdot \left(y \cdot \left(1 + -1 \cdot x\right)\right) + x} \]
                              2. mul-1-negN/A

                                \[\leadsto -1 \cdot \left(y \cdot \left(1 + \color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right) + x \]
                              3. sub-negN/A

                                \[\leadsto -1 \cdot \left(y \cdot \color{blue}{\left(1 - x\right)}\right) + x \]
                              4. mul-1-negN/A

                                \[\leadsto \color{blue}{\left(\mathsf{neg}\left(y \cdot \left(1 - x\right)\right)\right)} + x \]
                              5. distribute-rgt-neg-inN/A

                                \[\leadsto \color{blue}{y \cdot \left(\mathsf{neg}\left(\left(1 - x\right)\right)\right)} + x \]
                              6. mul-1-negN/A

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

                                \[\leadsto \color{blue}{\mathsf{fma}\left(y, -1 \cdot \left(1 - x\right), x\right)} \]
                              8. sub-negN/A

                                \[\leadsto \mathsf{fma}\left(y, -1 \cdot \color{blue}{\left(1 + \left(\mathsf{neg}\left(x\right)\right)\right)}, x\right) \]
                              9. mul-1-negN/A

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

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

                                \[\leadsto \mathsf{fma}\left(y, \color{blue}{-1} + -1 \cdot \left(-1 \cdot x\right), x\right) \]
                              12. neg-mul-1N/A

                                \[\leadsto \mathsf{fma}\left(y, -1 + \color{blue}{\left(\mathsf{neg}\left(-1 \cdot x\right)\right)}, x\right) \]
                              13. mul-1-negN/A

                                \[\leadsto \mathsf{fma}\left(y, -1 + \left(\mathsf{neg}\left(\color{blue}{\left(\mathsf{neg}\left(x\right)\right)}\right)\right), x\right) \]
                              14. remove-double-negN/A

                                \[\leadsto \mathsf{fma}\left(y, -1 + \color{blue}{x}, x\right) \]
                              15. lower-+.f6496.6

                                \[\leadsto \mathsf{fma}\left(y, \color{blue}{-1 + x}, x\right) \]
                            4. Applied rewrites96.6%

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

                              \[\leadsto \mathsf{fma}\left(y, -1, x\right) \]
                            6. Step-by-step derivation
                              1. Applied rewrites96.8%

                                \[\leadsto \mathsf{fma}\left(y, -1, x\right) \]
                            7. Recombined 2 regimes into one program.
                            8. Add Preprocessing

                            Alternative 9: 73.0% accurate, 0.9× speedup?

                            \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y \leq -8.4 \cdot 10^{-25}:\\ \;\;\;\;1\\ \mathbf{elif}\;y \leq 1:\\ \;\;\;\;\mathsf{fma}\left(y, x, x\right)\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
                            (FPCore (x y)
                             :precision binary64
                             (if (<= y -8.4e-25) 1.0 (if (<= y 1.0) (fma y x x) 1.0)))
                            double code(double x, double y) {
                            	double tmp;
                            	if (y <= -8.4e-25) {
                            		tmp = 1.0;
                            	} else if (y <= 1.0) {
                            		tmp = fma(y, x, x);
                            	} else {
                            		tmp = 1.0;
                            	}
                            	return tmp;
                            }
                            
                            function code(x, y)
                            	tmp = 0.0
                            	if (y <= -8.4e-25)
                            		tmp = 1.0;
                            	elseif (y <= 1.0)
                            		tmp = fma(y, x, x);
                            	else
                            		tmp = 1.0;
                            	end
                            	return tmp
                            end
                            
                            code[x_, y_] := If[LessEqual[y, -8.4e-25], 1.0, If[LessEqual[y, 1.0], N[(y * x + x), $MachinePrecision], 1.0]]
                            
                            \begin{array}{l}
                            
                            \\
                            \begin{array}{l}
                            \mathbf{if}\;y \leq -8.4 \cdot 10^{-25}:\\
                            \;\;\;\;1\\
                            
                            \mathbf{elif}\;y \leq 1:\\
                            \;\;\;\;\mathsf{fma}\left(y, x, x\right)\\
                            
                            \mathbf{else}:\\
                            \;\;\;\;1\\
                            
                            
                            \end{array}
                            \end{array}
                            
                            Derivation
                            1. Split input into 2 regimes
                            2. if y < -8.40000000000000009e-25 or 1 < y

                              1. Initial program 100.0%

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

                                \[\leadsto \color{blue}{1} \]
                              4. Step-by-step derivation
                                1. Applied rewrites76.3%

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

                                if -8.40000000000000009e-25 < y < 1

                                1. Initial program 100.0%

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

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

                                    \[\leadsto \color{blue}{\frac{x}{1 - y}} \]
                                  2. lower--.f6476.2

                                    \[\leadsto \frac{x}{\color{blue}{1 - y}} \]
                                5. Applied rewrites76.2%

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

                                  \[\leadsto x + \color{blue}{x \cdot y} \]
                                7. Step-by-step derivation
                                  1. Applied rewrites76.2%

                                    \[\leadsto \mathsf{fma}\left(y, \color{blue}{x}, x\right) \]
                                8. Recombined 2 regimes into one program.
                                9. Add Preprocessing

                                Alternative 10: 37.7% accurate, 18.0× speedup?

                                \[\begin{array}{l} \\ 1 \end{array} \]
                                (FPCore (x y) :precision binary64 1.0)
                                double code(double x, double y) {
                                	return 1.0;
                                }
                                
                                real(8) function code(x, y)
                                    real(8), intent (in) :: x
                                    real(8), intent (in) :: y
                                    code = 1.0d0
                                end function
                                
                                public static double code(double x, double y) {
                                	return 1.0;
                                }
                                
                                def code(x, y):
                                	return 1.0
                                
                                function code(x, y)
                                	return 1.0
                                end
                                
                                function tmp = code(x, y)
                                	tmp = 1.0;
                                end
                                
                                code[x_, y_] := 1.0
                                
                                \begin{array}{l}
                                
                                \\
                                1
                                \end{array}
                                
                                Derivation
                                1. Initial program 100.0%

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

                                  \[\leadsto \color{blue}{1} \]
                                4. Step-by-step derivation
                                  1. Applied rewrites41.7%

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

                                  Reproduce

                                  ?
                                  herbie shell --seed 2024220 
                                  (FPCore (x y)
                                    :name "Diagrams.Trail:splitAtParam  from diagrams-lib-1.3.0.3, C"
                                    :precision binary64
                                    (/ (- x y) (- 1.0 y)))