Diagrams.TwoD.Arc:arcBetween from diagrams-lib-1.3.0.3

Percentage Accurate: 50.0% → 81.6%
Time: 6.8s
Alternatives: 5
Speedup: 0.9×

Specification

?
\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(y \cdot 4\right) \cdot y\\ \frac{x \cdot x - t\_0}{x \cdot x + t\_0} \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (* (* y 4.0) y))) (/ (- (* x x) t_0) (+ (* x x) t_0))))
double code(double x, double y) {
	double t_0 = (y * 4.0) * y;
	return ((x * x) - t_0) / ((x * x) + t_0);
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    t_0 = (y * 4.0d0) * y
    code = ((x * x) - t_0) / ((x * x) + t_0)
end function
public static double code(double x, double y) {
	double t_0 = (y * 4.0) * y;
	return ((x * x) - t_0) / ((x * x) + t_0);
}
def code(x, y):
	t_0 = (y * 4.0) * y
	return ((x * x) - t_0) / ((x * x) + t_0)
function code(x, y)
	t_0 = Float64(Float64(y * 4.0) * y)
	return Float64(Float64(Float64(x * x) - t_0) / Float64(Float64(x * x) + t_0))
end
function tmp = code(x, y)
	t_0 = (y * 4.0) * y;
	tmp = ((x * x) - t_0) / ((x * x) + t_0);
end
code[x_, y_] := Block[{t$95$0 = N[(N[(y * 4.0), $MachinePrecision] * y), $MachinePrecision]}, N[(N[(N[(x * x), $MachinePrecision] - t$95$0), $MachinePrecision] / N[(N[(x * x), $MachinePrecision] + t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(y \cdot 4\right) \cdot y\\
\frac{x \cdot x - t\_0}{x \cdot x + t\_0}
\end{array}
\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 5 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: 50.0% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(y \cdot 4\right) \cdot y\\ \frac{x \cdot x - t\_0}{x \cdot x + t\_0} \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (* (* y 4.0) y))) (/ (- (* x x) t_0) (+ (* x x) t_0))))
double code(double x, double y) {
	double t_0 = (y * 4.0) * y;
	return ((x * x) - t_0) / ((x * x) + t_0);
}
real(8) function code(x, y)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8) :: t_0
    t_0 = (y * 4.0d0) * y
    code = ((x * x) - t_0) / ((x * x) + t_0)
end function
public static double code(double x, double y) {
	double t_0 = (y * 4.0) * y;
	return ((x * x) - t_0) / ((x * x) + t_0);
}
def code(x, y):
	t_0 = (y * 4.0) * y
	return ((x * x) - t_0) / ((x * x) + t_0)
function code(x, y)
	t_0 = Float64(Float64(y * 4.0) * y)
	return Float64(Float64(Float64(x * x) - t_0) / Float64(Float64(x * x) + t_0))
end
function tmp = code(x, y)
	t_0 = (y * 4.0) * y;
	tmp = ((x * x) - t_0) / ((x * x) + t_0);
end
code[x_, y_] := Block[{t$95$0 = N[(N[(y * 4.0), $MachinePrecision] * y), $MachinePrecision]}, N[(N[(N[(x * x), $MachinePrecision] - t$95$0), $MachinePrecision] / N[(N[(x * x), $MachinePrecision] + t$95$0), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(y \cdot 4\right) \cdot y\\
\frac{x \cdot x - t\_0}{x \cdot x + t\_0}
\end{array}
\end{array}

Alternative 1: 81.6% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \cdot x \leq 2 \cdot 10^{-317}:\\ \;\;\;\;\mathsf{fma}\left(\frac{0.5 \cdot x}{y}, \frac{x}{y}, -1\right)\\ \mathbf{elif}\;x \cdot x \leq 2 \cdot 10^{+268}:\\ \;\;\;\;\frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{\mathsf{fma}\left(y \cdot y, 4, x \cdot x\right)}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{\frac{-8}{x} \cdot y}{x}, y, 1\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (if (<= (* x x) 2e-317)
   (fma (/ (* 0.5 x) y) (/ x y) -1.0)
   (if (<= (* x x) 2e+268)
     (/ (fma -4.0 (* y y) (* x x)) (fma (* y y) 4.0 (* x x)))
     (fma (/ (* (/ -8.0 x) y) x) y 1.0))))
double code(double x, double y) {
	double tmp;
	if ((x * x) <= 2e-317) {
		tmp = fma(((0.5 * x) / y), (x / y), -1.0);
	} else if ((x * x) <= 2e+268) {
		tmp = fma(-4.0, (y * y), (x * x)) / fma((y * y), 4.0, (x * x));
	} else {
		tmp = fma((((-8.0 / x) * y) / x), y, 1.0);
	}
	return tmp;
}
function code(x, y)
	tmp = 0.0
	if (Float64(x * x) <= 2e-317)
		tmp = fma(Float64(Float64(0.5 * x) / y), Float64(x / y), -1.0);
	elseif (Float64(x * x) <= 2e+268)
		tmp = Float64(fma(-4.0, Float64(y * y), Float64(x * x)) / fma(Float64(y * y), 4.0, Float64(x * x)));
	else
		tmp = fma(Float64(Float64(Float64(-8.0 / x) * y) / x), y, 1.0);
	end
	return tmp
end
code[x_, y_] := If[LessEqual[N[(x * x), $MachinePrecision], 2e-317], N[(N[(N[(0.5 * x), $MachinePrecision] / y), $MachinePrecision] * N[(x / y), $MachinePrecision] + -1.0), $MachinePrecision], If[LessEqual[N[(x * x), $MachinePrecision], 2e+268], N[(N[(-4.0 * N[(y * y), $MachinePrecision] + N[(x * x), $MachinePrecision]), $MachinePrecision] / N[(N[(y * y), $MachinePrecision] * 4.0 + N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(N[(N[(N[(-8.0 / x), $MachinePrecision] * y), $MachinePrecision] / x), $MachinePrecision] * y + 1.0), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;x \cdot x \leq 2 \cdot 10^{-317}:\\
\;\;\;\;\mathsf{fma}\left(\frac{0.5 \cdot x}{y}, \frac{x}{y}, -1\right)\\

\mathbf{elif}\;x \cdot x \leq 2 \cdot 10^{+268}:\\
\;\;\;\;\frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{\mathsf{fma}\left(y \cdot y, 4, x \cdot x\right)}\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\frac{\frac{-8}{x} \cdot y}{x}, y, 1\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 x x) < 1.99999997e-317

    1. Initial program 48.6%

      \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{x}^{2}}{{y}^{2}} - 1} \]
    4. Step-by-step derivation
      1. sub-negN/A

        \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{x}^{2}}{{y}^{2}} + \left(\mathsf{neg}\left(1\right)\right)} \]
      2. unpow2N/A

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

        \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(x \cdot \frac{x}{{y}^{2}}\right)} + \left(\mathsf{neg}\left(1\right)\right) \]
      4. associate-*r*N/A

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{1}{2} \cdot x, \frac{x}{\color{blue}{y \cdot y}}, \mathsf{neg}\left(1\right)\right) \]
      10. metadata-eval75.7

        \[\leadsto \mathsf{fma}\left(0.5 \cdot x, \frac{x}{y \cdot y}, \color{blue}{-1}\right) \]
    5. Applied rewrites75.7%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.5 \cdot x, \frac{x}{y \cdot y}, -1\right)} \]
    6. Step-by-step derivation
      1. Applied rewrites80.3%

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

      if 1.99999997e-317 < (*.f64 x x) < 1.9999999999999999e268

      1. Initial program 76.8%

        \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
      2. Add Preprocessing
      3. Step-by-step derivation
        1. lift--.f64N/A

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

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

          \[\leadsto \frac{\color{blue}{\left(\mathsf{neg}\left(\left(y \cdot 4\right) \cdot y\right)\right) + x \cdot x}}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
        4. lift-*.f64N/A

          \[\leadsto \frac{\left(\mathsf{neg}\left(\color{blue}{\left(y \cdot 4\right) \cdot y}\right)\right) + x \cdot x}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
        5. lift-*.f64N/A

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

          \[\leadsto \frac{\left(\mathsf{neg}\left(\color{blue}{\left(4 \cdot y\right)} \cdot y\right)\right) + x \cdot x}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
        7. associate-*l*N/A

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

          \[\leadsto \frac{\color{blue}{\left(\mathsf{neg}\left(4\right)\right) \cdot \left(y \cdot y\right)} + x \cdot x}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
        9. lower-fma.f64N/A

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

          \[\leadsto \frac{\mathsf{fma}\left(\color{blue}{-4}, y \cdot y, x \cdot x\right)}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
        11. lower-*.f6476.8

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

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

          \[\leadsto \frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{\color{blue}{\left(y \cdot 4\right) \cdot y + x \cdot x}} \]
        14. lift-*.f64N/A

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

          \[\leadsto \frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{\color{blue}{y \cdot \left(y \cdot 4\right)} + x \cdot x} \]
        16. lift-*.f64N/A

          \[\leadsto \frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{y \cdot \color{blue}{\left(y \cdot 4\right)} + x \cdot x} \]
        17. associate-*r*N/A

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

          \[\leadsto \frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{\color{blue}{\mathsf{fma}\left(y \cdot y, 4, x \cdot x\right)}} \]
        19. lower-*.f6476.8

          \[\leadsto \frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{\mathsf{fma}\left(\color{blue}{y \cdot y}, 4, x \cdot x\right)} \]
      4. Applied rewrites76.8%

        \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{\mathsf{fma}\left(y \cdot y, 4, x \cdot x\right)}} \]

      if 1.9999999999999999e268 < (*.f64 x x)

      1. Initial program 6.6%

        \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
      2. Add Preprocessing
      3. Taylor expanded in x around inf

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

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

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

          \[\leadsto 1 + \frac{{y}^{2}}{{x}^{2}} \cdot \color{blue}{-8} \]
        4. *-commutativeN/A

          \[\leadsto 1 + \color{blue}{-8 \cdot \frac{{y}^{2}}{{x}^{2}}} \]
        5. +-commutativeN/A

          \[\leadsto \color{blue}{-8 \cdot \frac{{y}^{2}}{{x}^{2}} + 1} \]
        6. associate-*r/N/A

          \[\leadsto \color{blue}{\frac{-8 \cdot {y}^{2}}{{x}^{2}}} + 1 \]
        7. associate-*l/N/A

          \[\leadsto \color{blue}{\frac{-8}{{x}^{2}} \cdot {y}^{2}} + 1 \]
        8. metadata-evalN/A

          \[\leadsto \frac{\color{blue}{\mathsf{neg}\left(8\right)}}{{x}^{2}} \cdot {y}^{2} + 1 \]
        9. distribute-neg-fracN/A

          \[\leadsto \color{blue}{\left(\mathsf{neg}\left(\frac{8}{{x}^{2}}\right)\right)} \cdot {y}^{2} + 1 \]
        10. metadata-evalN/A

          \[\leadsto \left(\mathsf{neg}\left(\frac{\color{blue}{8 \cdot 1}}{{x}^{2}}\right)\right) \cdot {y}^{2} + 1 \]
        11. associate-*r/N/A

          \[\leadsto \left(\mathsf{neg}\left(\color{blue}{8 \cdot \frac{1}{{x}^{2}}}\right)\right) \cdot {y}^{2} + 1 \]
        12. unpow2N/A

          \[\leadsto \left(\mathsf{neg}\left(8 \cdot \frac{1}{{x}^{2}}\right)\right) \cdot \color{blue}{\left(y \cdot y\right)} + 1 \]
        13. associate-*r*N/A

          \[\leadsto \color{blue}{\left(\left(\mathsf{neg}\left(8 \cdot \frac{1}{{x}^{2}}\right)\right) \cdot y\right) \cdot y} + 1 \]
        14. lower-fma.f64N/A

          \[\leadsto \color{blue}{\mathsf{fma}\left(\left(\mathsf{neg}\left(8 \cdot \frac{1}{{x}^{2}}\right)\right) \cdot y, y, 1\right)} \]
      5. Applied rewrites89.2%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-8}{x \cdot x} \cdot y, y, 1\right)} \]
      6. Step-by-step derivation
        1. Applied rewrites90.4%

          \[\leadsto \mathsf{fma}\left(\frac{\frac{-8}{x} \cdot y}{x}, y, 1\right) \]
      7. Recombined 3 regimes into one program.
      8. Add Preprocessing

      Alternative 2: 76.0% accurate, 0.6× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(4 \cdot y\right) \cdot y\\ \mathbf{if}\;\frac{x \cdot x - t\_0}{t\_0 + x \cdot x} \leq -0.5:\\ \;\;\;\;\mathsf{fma}\left(0.5 \cdot x, \frac{x}{y \cdot y}, -1\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{\frac{-8}{x} \cdot y}{x}, y, 1\right)\\ \end{array} \end{array} \]
      (FPCore (x y)
       :precision binary64
       (let* ((t_0 (* (* 4.0 y) y)))
         (if (<= (/ (- (* x x) t_0) (+ t_0 (* x x))) -0.5)
           (fma (* 0.5 x) (/ x (* y y)) -1.0)
           (fma (/ (* (/ -8.0 x) y) x) y 1.0))))
      double code(double x, double y) {
      	double t_0 = (4.0 * y) * y;
      	double tmp;
      	if ((((x * x) - t_0) / (t_0 + (x * x))) <= -0.5) {
      		tmp = fma((0.5 * x), (x / (y * y)), -1.0);
      	} else {
      		tmp = fma((((-8.0 / x) * y) / x), y, 1.0);
      	}
      	return tmp;
      }
      
      function code(x, y)
      	t_0 = Float64(Float64(4.0 * y) * y)
      	tmp = 0.0
      	if (Float64(Float64(Float64(x * x) - t_0) / Float64(t_0 + Float64(x * x))) <= -0.5)
      		tmp = fma(Float64(0.5 * x), Float64(x / Float64(y * y)), -1.0);
      	else
      		tmp = fma(Float64(Float64(Float64(-8.0 / x) * y) / x), y, 1.0);
      	end
      	return tmp
      end
      
      code[x_, y_] := Block[{t$95$0 = N[(N[(4.0 * y), $MachinePrecision] * y), $MachinePrecision]}, If[LessEqual[N[(N[(N[(x * x), $MachinePrecision] - t$95$0), $MachinePrecision] / N[(t$95$0 + N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], -0.5], N[(N[(0.5 * x), $MachinePrecision] * N[(x / N[(y * y), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision], N[(N[(N[(N[(-8.0 / x), $MachinePrecision] * y), $MachinePrecision] / x), $MachinePrecision] * y + 1.0), $MachinePrecision]]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      t_0 := \left(4 \cdot y\right) \cdot y\\
      \mathbf{if}\;\frac{x \cdot x - t\_0}{t\_0 + x \cdot x} \leq -0.5:\\
      \;\;\;\;\mathsf{fma}\left(0.5 \cdot x, \frac{x}{y \cdot y}, -1\right)\\
      
      \mathbf{else}:\\
      \;\;\;\;\mathsf{fma}\left(\frac{\frac{-8}{x} \cdot y}{x}, y, 1\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (/.f64 (-.f64 (*.f64 x x) (*.f64 (*.f64 y #s(literal 4 binary64)) y)) (+.f64 (*.f64 x x) (*.f64 (*.f64 y #s(literal 4 binary64)) y))) < -0.5

        1. Initial program 100.0%

          \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
        2. Add Preprocessing
        3. Taylor expanded in x around 0

          \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{x}^{2}}{{y}^{2}} - 1} \]
        4. Step-by-step derivation
          1. sub-negN/A

            \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{x}^{2}}{{y}^{2}} + \left(\mathsf{neg}\left(1\right)\right)} \]
          2. unpow2N/A

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

            \[\leadsto \frac{1}{2} \cdot \color{blue}{\left(x \cdot \frac{x}{{y}^{2}}\right)} + \left(\mathsf{neg}\left(1\right)\right) \]
          4. associate-*r*N/A

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

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

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

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

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

            \[\leadsto \mathsf{fma}\left(\frac{1}{2} \cdot x, \frac{x}{\color{blue}{y \cdot y}}, \mathsf{neg}\left(1\right)\right) \]
          10. metadata-eval99.5

            \[\leadsto \mathsf{fma}\left(0.5 \cdot x, \frac{x}{y \cdot y}, \color{blue}{-1}\right) \]
        5. Applied rewrites99.5%

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

        if -0.5 < (/.f64 (-.f64 (*.f64 x x) (*.f64 (*.f64 y #s(literal 4 binary64)) y)) (+.f64 (*.f64 x x) (*.f64 (*.f64 y #s(literal 4 binary64)) y)))

        1. Initial program 33.8%

          \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
        2. Add Preprocessing
        3. Taylor expanded in x around inf

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

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

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

            \[\leadsto 1 + \frac{{y}^{2}}{{x}^{2}} \cdot \color{blue}{-8} \]
          4. *-commutativeN/A

            \[\leadsto 1 + \color{blue}{-8 \cdot \frac{{y}^{2}}{{x}^{2}}} \]
          5. +-commutativeN/A

            \[\leadsto \color{blue}{-8 \cdot \frac{{y}^{2}}{{x}^{2}} + 1} \]
          6. associate-*r/N/A

            \[\leadsto \color{blue}{\frac{-8 \cdot {y}^{2}}{{x}^{2}}} + 1 \]
          7. associate-*l/N/A

            \[\leadsto \color{blue}{\frac{-8}{{x}^{2}} \cdot {y}^{2}} + 1 \]
          8. metadata-evalN/A

            \[\leadsto \frac{\color{blue}{\mathsf{neg}\left(8\right)}}{{x}^{2}} \cdot {y}^{2} + 1 \]
          9. distribute-neg-fracN/A

            \[\leadsto \color{blue}{\left(\mathsf{neg}\left(\frac{8}{{x}^{2}}\right)\right)} \cdot {y}^{2} + 1 \]
          10. metadata-evalN/A

            \[\leadsto \left(\mathsf{neg}\left(\frac{\color{blue}{8 \cdot 1}}{{x}^{2}}\right)\right) \cdot {y}^{2} + 1 \]
          11. associate-*r/N/A

            \[\leadsto \left(\mathsf{neg}\left(\color{blue}{8 \cdot \frac{1}{{x}^{2}}}\right)\right) \cdot {y}^{2} + 1 \]
          12. unpow2N/A

            \[\leadsto \left(\mathsf{neg}\left(8 \cdot \frac{1}{{x}^{2}}\right)\right) \cdot \color{blue}{\left(y \cdot y\right)} + 1 \]
          13. associate-*r*N/A

            \[\leadsto \color{blue}{\left(\left(\mathsf{neg}\left(8 \cdot \frac{1}{{x}^{2}}\right)\right) \cdot y\right) \cdot y} + 1 \]
          14. lower-fma.f64N/A

            \[\leadsto \color{blue}{\mathsf{fma}\left(\left(\mathsf{neg}\left(8 \cdot \frac{1}{{x}^{2}}\right)\right) \cdot y, y, 1\right)} \]
        5. Applied rewrites64.0%

          \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{-8}{x \cdot x} \cdot y, y, 1\right)} \]
        6. Step-by-step derivation
          1. Applied rewrites68.4%

            \[\leadsto \mathsf{fma}\left(\frac{\frac{-8}{x} \cdot y}{x}, y, 1\right) \]
        7. Recombined 2 regimes into one program.
        8. Final simplification76.0%

          \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{x \cdot x - \left(4 \cdot y\right) \cdot y}{\left(4 \cdot y\right) \cdot y + x \cdot x} \leq -0.5:\\ \;\;\;\;\mathsf{fma}\left(0.5 \cdot x, \frac{x}{y \cdot y}, -1\right)\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{\frac{-8}{x} \cdot y}{x}, y, 1\right)\\ \end{array} \]
        9. Add Preprocessing

        Developer Target 1: 50.5% accurate, 0.2× speedup?

        \[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(y \cdot y\right) \cdot 4\\ t_1 := x \cdot x + t\_0\\ t_2 := \frac{t\_0}{t\_1}\\ t_3 := \left(y \cdot 4\right) \cdot y\\ \mathbf{if}\;\frac{x \cdot x - t\_3}{x \cdot x + t\_3} < 0.9743233849626781:\\ \;\;\;\;\frac{x \cdot x}{t\_1} - t\_2\\ \mathbf{else}:\\ \;\;\;\;{\left(\frac{x}{\sqrt{t\_1}}\right)}^{2} - t\_2\\ \end{array} \end{array} \]
        (FPCore (x y)
         :precision binary64
         (let* ((t_0 (* (* y y) 4.0))
                (t_1 (+ (* x x) t_0))
                (t_2 (/ t_0 t_1))
                (t_3 (* (* y 4.0) y)))
           (if (< (/ (- (* x x) t_3) (+ (* x x) t_3)) 0.9743233849626781)
             (- (/ (* x x) t_1) t_2)
             (- (pow (/ x (sqrt t_1)) 2.0) t_2))))
        double code(double x, double y) {
        	double t_0 = (y * y) * 4.0;
        	double t_1 = (x * x) + t_0;
        	double t_2 = t_0 / t_1;
        	double t_3 = (y * 4.0) * y;
        	double tmp;
        	if ((((x * x) - t_3) / ((x * x) + t_3)) < 0.9743233849626781) {
        		tmp = ((x * x) / t_1) - t_2;
        	} else {
        		tmp = pow((x / sqrt(t_1)), 2.0) - t_2;
        	}
        	return tmp;
        }
        
        real(8) function code(x, y)
            real(8), intent (in) :: x
            real(8), intent (in) :: y
            real(8) :: t_0
            real(8) :: t_1
            real(8) :: t_2
            real(8) :: t_3
            real(8) :: tmp
            t_0 = (y * y) * 4.0d0
            t_1 = (x * x) + t_0
            t_2 = t_0 / t_1
            t_3 = (y * 4.0d0) * y
            if ((((x * x) - t_3) / ((x * x) + t_3)) < 0.9743233849626781d0) then
                tmp = ((x * x) / t_1) - t_2
            else
                tmp = ((x / sqrt(t_1)) ** 2.0d0) - t_2
            end if
            code = tmp
        end function
        
        public static double code(double x, double y) {
        	double t_0 = (y * y) * 4.0;
        	double t_1 = (x * x) + t_0;
        	double t_2 = t_0 / t_1;
        	double t_3 = (y * 4.0) * y;
        	double tmp;
        	if ((((x * x) - t_3) / ((x * x) + t_3)) < 0.9743233849626781) {
        		tmp = ((x * x) / t_1) - t_2;
        	} else {
        		tmp = Math.pow((x / Math.sqrt(t_1)), 2.0) - t_2;
        	}
        	return tmp;
        }
        
        def code(x, y):
        	t_0 = (y * y) * 4.0
        	t_1 = (x * x) + t_0
        	t_2 = t_0 / t_1
        	t_3 = (y * 4.0) * y
        	tmp = 0
        	if (((x * x) - t_3) / ((x * x) + t_3)) < 0.9743233849626781:
        		tmp = ((x * x) / t_1) - t_2
        	else:
        		tmp = math.pow((x / math.sqrt(t_1)), 2.0) - t_2
        	return tmp
        
        function code(x, y)
        	t_0 = Float64(Float64(y * y) * 4.0)
        	t_1 = Float64(Float64(x * x) + t_0)
        	t_2 = Float64(t_0 / t_1)
        	t_3 = Float64(Float64(y * 4.0) * y)
        	tmp = 0.0
        	if (Float64(Float64(Float64(x * x) - t_3) / Float64(Float64(x * x) + t_3)) < 0.9743233849626781)
        		tmp = Float64(Float64(Float64(x * x) / t_1) - t_2);
        	else
        		tmp = Float64((Float64(x / sqrt(t_1)) ^ 2.0) - t_2);
        	end
        	return tmp
        end
        
        function tmp_2 = code(x, y)
        	t_0 = (y * y) * 4.0;
        	t_1 = (x * x) + t_0;
        	t_2 = t_0 / t_1;
        	t_3 = (y * 4.0) * y;
        	tmp = 0.0;
        	if ((((x * x) - t_3) / ((x * x) + t_3)) < 0.9743233849626781)
        		tmp = ((x * x) / t_1) - t_2;
        	else
        		tmp = ((x / sqrt(t_1)) ^ 2.0) - t_2;
        	end
        	tmp_2 = tmp;
        end
        
        code[x_, y_] := Block[{t$95$0 = N[(N[(y * y), $MachinePrecision] * 4.0), $MachinePrecision]}, Block[{t$95$1 = N[(N[(x * x), $MachinePrecision] + t$95$0), $MachinePrecision]}, Block[{t$95$2 = N[(t$95$0 / t$95$1), $MachinePrecision]}, Block[{t$95$3 = N[(N[(y * 4.0), $MachinePrecision] * y), $MachinePrecision]}, If[Less[N[(N[(N[(x * x), $MachinePrecision] - t$95$3), $MachinePrecision] / N[(N[(x * x), $MachinePrecision] + t$95$3), $MachinePrecision]), $MachinePrecision], 0.9743233849626781], N[(N[(N[(x * x), $MachinePrecision] / t$95$1), $MachinePrecision] - t$95$2), $MachinePrecision], N[(N[Power[N[(x / N[Sqrt[t$95$1], $MachinePrecision]), $MachinePrecision], 2.0], $MachinePrecision] - t$95$2), $MachinePrecision]]]]]]
        
        \begin{array}{l}
        
        \\
        \begin{array}{l}
        t_0 := \left(y \cdot y\right) \cdot 4\\
        t_1 := x \cdot x + t\_0\\
        t_2 := \frac{t\_0}{t\_1}\\
        t_3 := \left(y \cdot 4\right) \cdot y\\
        \mathbf{if}\;\frac{x \cdot x - t\_3}{x \cdot x + t\_3} < 0.9743233849626781:\\
        \;\;\;\;\frac{x \cdot x}{t\_1} - t\_2\\
        
        \mathbf{else}:\\
        \;\;\;\;{\left(\frac{x}{\sqrt{t\_1}}\right)}^{2} - t\_2\\
        
        
        \end{array}
        \end{array}
        

        Reproduce

        ?
        herbie shell --seed 2024230 
        (FPCore (x y)
          :name "Diagrams.TwoD.Arc:arcBetween from diagrams-lib-1.3.0.3"
          :precision binary64
        
          :alt
          (! :herbie-platform default (if (< (/ (- (* x x) (* (* y 4) y)) (+ (* x x) (* (* y 4) y))) 9743233849626781/10000000000000000) (- (/ (* x x) (+ (* x x) (* (* y y) 4))) (/ (* (* y y) 4) (+ (* x x) (* (* y y) 4)))) (- (pow (/ x (sqrt (+ (* x x) (* (* y y) 4)))) 2) (/ (* (* y y) 4) (+ (* x x) (* (* y y) 4))))))
        
          (/ (- (* x x) (* (* y 4.0) y)) (+ (* x x) (* (* y 4.0) y))))