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

Percentage Accurate: 50.7% → 78.9%
Time: 25.5s
Alternatives: 5
Speedup: 2.4×

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: 50.7% 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: 78.9% accurate, 0.1× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(\frac{x}{y} \cdot \frac{x}{y}\right) \cdot 0.3333333333333333\\ t_1 := y \cdot \left(y \cdot 4\right)\\ \mathbf{if}\;x \cdot x \leq 10^{-167}:\\ \;\;\;\;\mathsf{fma}\left(0.5, t\_0 + \left(e^{\mathsf{log1p}\left(2 \cdot t\_0\right)} + -1\right), -1\right)\\ \mathbf{elif}\;x \cdot x \leq 10^{+46}:\\ \;\;\;\;\frac{x \cdot x - t\_1}{x \cdot x + t\_1}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (* (* (/ x y) (/ x y)) 0.3333333333333333)) (t_1 (* y (* y 4.0))))
   (if (<= (* x x) 1e-167)
     (fma 0.5 (+ t_0 (+ (exp (log1p (* 2.0 t_0))) -1.0)) -1.0)
     (if (<= (* x x) 1e+46) (/ (- (* x x) t_1) (+ (* x x) t_1)) 1.0))))
double code(double x, double y) {
	double t_0 = ((x / y) * (x / y)) * 0.3333333333333333;
	double t_1 = y * (y * 4.0);
	double tmp;
	if ((x * x) <= 1e-167) {
		tmp = fma(0.5, (t_0 + (exp(log1p((2.0 * t_0))) + -1.0)), -1.0);
	} else if ((x * x) <= 1e+46) {
		tmp = ((x * x) - t_1) / ((x * x) + t_1);
	} else {
		tmp = 1.0;
	}
	return tmp;
}
function code(x, y)
	t_0 = Float64(Float64(Float64(x / y) * Float64(x / y)) * 0.3333333333333333)
	t_1 = Float64(y * Float64(y * 4.0))
	tmp = 0.0
	if (Float64(x * x) <= 1e-167)
		tmp = fma(0.5, Float64(t_0 + Float64(exp(log1p(Float64(2.0 * t_0))) + -1.0)), -1.0);
	elseif (Float64(x * x) <= 1e+46)
		tmp = Float64(Float64(Float64(x * x) - t_1) / Float64(Float64(x * x) + t_1));
	else
		tmp = 1.0;
	end
	return tmp
end
code[x_, y_] := Block[{t$95$0 = N[(N[(N[(x / y), $MachinePrecision] * N[(x / y), $MachinePrecision]), $MachinePrecision] * 0.3333333333333333), $MachinePrecision]}, Block[{t$95$1 = N[(y * N[(y * 4.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(x * x), $MachinePrecision], 1e-167], N[(0.5 * N[(t$95$0 + N[(N[Exp[N[Log[1 + N[(2.0 * t$95$0), $MachinePrecision]], $MachinePrecision]], $MachinePrecision] + -1.0), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision], If[LessEqual[N[(x * x), $MachinePrecision], 1e+46], N[(N[(N[(x * x), $MachinePrecision] - t$95$1), $MachinePrecision] / N[(N[(x * x), $MachinePrecision] + t$95$1), $MachinePrecision]), $MachinePrecision], 1.0]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(\frac{x}{y} \cdot \frac{x}{y}\right) \cdot 0.3333333333333333\\
t_1 := y \cdot \left(y \cdot 4\right)\\
\mathbf{if}\;x \cdot x \leq 10^{-167}:\\
\;\;\;\;\mathsf{fma}\left(0.5, t\_0 + \left(e^{\mathsf{log1p}\left(2 \cdot t\_0\right)} + -1\right), -1\right)\\

\mathbf{elif}\;x \cdot x \leq 10^{+46}:\\
\;\;\;\;\frac{x \cdot x - t\_1}{x \cdot x + t\_1}\\

\mathbf{else}:\\
\;\;\;\;1\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 x x) < 1e-167

    1. Initial program 55.2%

      \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 80.3%

      \[\leadsto \color{blue}{0.5 \cdot \frac{{x}^{2}}{{y}^{2}} - 1} \]
    4. Step-by-step derivation
      1. fma-neg80.3%

        \[\leadsto \color{blue}{\mathsf{fma}\left(0.5, \frac{{x}^{2}}{{y}^{2}}, -1\right)} \]
      2. unpow280.3%

        \[\leadsto \mathsf{fma}\left(0.5, \frac{\color{blue}{x \cdot x}}{{y}^{2}}, -1\right) \]
      3. unpow280.3%

        \[\leadsto \mathsf{fma}\left(0.5, \frac{x \cdot x}{\color{blue}{y \cdot y}}, -1\right) \]
      4. times-frac91.9%

        \[\leadsto \mathsf{fma}\left(0.5, \color{blue}{\frac{x}{y} \cdot \frac{x}{y}}, -1\right) \]
      5. metadata-eval91.9%

        \[\leadsto \mathsf{fma}\left(0.5, \frac{x}{y} \cdot \frac{x}{y}, \color{blue}{-1}\right) \]
    5. Simplified91.9%

      \[\leadsto \color{blue}{\mathsf{fma}\left(0.5, \frac{x}{y} \cdot \frac{x}{y}, -1\right)} \]
    6. Step-by-step derivation
      1. add-log-exp91.7%

        \[\leadsto \mathsf{fma}\left(0.5, \color{blue}{\log \left(e^{\frac{x}{y} \cdot \frac{x}{y}}\right)}, -1\right) \]
      2. add-cube-cbrt91.7%

        \[\leadsto \mathsf{fma}\left(0.5, \log \color{blue}{\left(\left(\sqrt[3]{e^{\frac{x}{y} \cdot \frac{x}{y}}} \cdot \sqrt[3]{e^{\frac{x}{y} \cdot \frac{x}{y}}}\right) \cdot \sqrt[3]{e^{\frac{x}{y} \cdot \frac{x}{y}}}\right)}, -1\right) \]
      3. log-prod91.7%

        \[\leadsto \mathsf{fma}\left(0.5, \color{blue}{\log \left(\sqrt[3]{e^{\frac{x}{y} \cdot \frac{x}{y}}} \cdot \sqrt[3]{e^{\frac{x}{y} \cdot \frac{x}{y}}}\right) + \log \left(\sqrt[3]{e^{\frac{x}{y} \cdot \frac{x}{y}}}\right)}, -1\right) \]
      4. frac-times80.3%

        \[\leadsto \mathsf{fma}\left(0.5, \log \left(\sqrt[3]{e^{\color{blue}{\frac{x \cdot x}{y \cdot y}}}} \cdot \sqrt[3]{e^{\frac{x}{y} \cdot \frac{x}{y}}}\right) + \log \left(\sqrt[3]{e^{\frac{x}{y} \cdot \frac{x}{y}}}\right), -1\right) \]
      5. frac-times80.3%

        \[\leadsto \mathsf{fma}\left(0.5, \log \left(\sqrt[3]{e^{\frac{x \cdot x}{y \cdot y}}} \cdot \sqrt[3]{e^{\color{blue}{\frac{x \cdot x}{y \cdot y}}}}\right) + \log \left(\sqrt[3]{e^{\frac{x}{y} \cdot \frac{x}{y}}}\right), -1\right) \]
      6. frac-times80.3%

        \[\leadsto \mathsf{fma}\left(0.5, \log \left(\sqrt[3]{e^{\frac{x \cdot x}{y \cdot y}}} \cdot \sqrt[3]{e^{\frac{x \cdot x}{y \cdot y}}}\right) + \log \left(\sqrt[3]{e^{\color{blue}{\frac{x \cdot x}{y \cdot y}}}}\right), -1\right) \]
    7. Applied egg-rr80.3%

      \[\leadsto \mathsf{fma}\left(0.5, \color{blue}{\log \left(\sqrt[3]{e^{\frac{x \cdot x}{y \cdot y}}} \cdot \sqrt[3]{e^{\frac{x \cdot x}{y \cdot y}}}\right) + \log \left(\sqrt[3]{e^{\frac{x \cdot x}{y \cdot y}}}\right)}, -1\right) \]
    8. Step-by-step derivation
      1. Simplified91.7%

        \[\leadsto \mathsf{fma}\left(0.5, \color{blue}{\log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}} \cdot \sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right) + \log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right)}, -1\right) \]
      2. Step-by-step derivation
        1. log1p-expm1-u91.7%

          \[\leadsto \mathsf{fma}\left(0.5, \log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}} \cdot \sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right) + \color{blue}{\mathsf{log1p}\left(\mathsf{expm1}\left(\log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right)\right)\right)}, -1\right) \]
        2. expm1-undefine91.7%

          \[\leadsto \mathsf{fma}\left(0.5, \log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}} \cdot \sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right) + \mathsf{log1p}\left(\color{blue}{e^{\log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right)} - 1}\right), -1\right) \]
        3. add-exp-log91.7%

          \[\leadsto \mathsf{fma}\left(0.5, \log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}} \cdot \sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right) + \mathsf{log1p}\left(\color{blue}{\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}} - 1\right), -1\right) \]
        4. pow1/391.7%

          \[\leadsto \mathsf{fma}\left(0.5, \log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}} \cdot \sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right) + \mathsf{log1p}\left(\color{blue}{{\left(e^{{\left(\frac{x}{y}\right)}^{2}}\right)}^{0.3333333333333333}} - 1\right), -1\right) \]
        5. pow-to-exp91.7%

          \[\leadsto \mathsf{fma}\left(0.5, \log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}} \cdot \sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right) + \mathsf{log1p}\left(\color{blue}{e^{\log \left(e^{{\left(\frac{x}{y}\right)}^{2}}\right) \cdot 0.3333333333333333}} - 1\right), -1\right) \]
        6. expm1-define91.7%

          \[\leadsto \mathsf{fma}\left(0.5, \log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}} \cdot \sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right) + \mathsf{log1p}\left(\color{blue}{\mathsf{expm1}\left(\log \left(e^{{\left(\frac{x}{y}\right)}^{2}}\right) \cdot 0.3333333333333333\right)}\right), -1\right) \]
        7. add-log-exp91.7%

          \[\leadsto \mathsf{fma}\left(0.5, \log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}} \cdot \sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right) + \mathsf{log1p}\left(\mathsf{expm1}\left(\color{blue}{{\left(\frac{x}{y}\right)}^{2}} \cdot 0.3333333333333333\right)\right), -1\right) \]
        8. log1p-expm1-u91.7%

          \[\leadsto \mathsf{fma}\left(0.5, \log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}} \cdot \sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right) + \color{blue}{{\left(\frac{x}{y}\right)}^{2} \cdot 0.3333333333333333}, -1\right) \]
        9. unpow291.7%

          \[\leadsto \mathsf{fma}\left(0.5, \log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}} \cdot \sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right) + \color{blue}{\left(\frac{x}{y} \cdot \frac{x}{y}\right)} \cdot 0.3333333333333333, -1\right) \]
      3. Applied egg-rr91.7%

        \[\leadsto \mathsf{fma}\left(0.5, \log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}} \cdot \sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right) + \color{blue}{\left(\frac{x}{y} \cdot \frac{x}{y}\right) \cdot 0.3333333333333333}, -1\right) \]
      4. Step-by-step derivation
        1. expm1-log1p-u91.7%

          \[\leadsto \mathsf{fma}\left(0.5, \color{blue}{\mathsf{expm1}\left(\mathsf{log1p}\left(\log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}} \cdot \sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right)\right)\right)} + \left(\frac{x}{y} \cdot \frac{x}{y}\right) \cdot 0.3333333333333333, -1\right) \]
        2. expm1-undefine91.7%

          \[\leadsto \mathsf{fma}\left(0.5, \color{blue}{\left(e^{\mathsf{log1p}\left(\log \left(\sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}} \cdot \sqrt[3]{e^{{\left(\frac{x}{y}\right)}^{2}}}\right)\right)} - 1\right)} + \left(\frac{x}{y} \cdot \frac{x}{y}\right) \cdot 0.3333333333333333, -1\right) \]
      5. Applied egg-rr91.9%

        \[\leadsto \mathsf{fma}\left(0.5, \color{blue}{\left(e^{\mathsf{log1p}\left(2 \cdot \left(\left(\frac{x}{y} \cdot \frac{x}{y}\right) \cdot 0.3333333333333333\right)\right)} - 1\right)} + \left(\frac{x}{y} \cdot \frac{x}{y}\right) \cdot 0.3333333333333333, -1\right) \]

      if 1e-167 < (*.f64 x x) < 9.9999999999999999e45

      1. Initial program 83.0%

        \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
      2. Add Preprocessing

      if 9.9999999999999999e45 < (*.f64 x x)

      1. Initial program 39.8%

        \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
      2. Add Preprocessing
      3. Taylor expanded in x around inf 82.6%

        \[\leadsto \color{blue}{1} \]
    9. Recombined 3 regimes into one program.
    10. Final simplification86.2%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \cdot x \leq 10^{-167}:\\ \;\;\;\;\mathsf{fma}\left(0.5, \left(\frac{x}{y} \cdot \frac{x}{y}\right) \cdot 0.3333333333333333 + \left(e^{\mathsf{log1p}\left(2 \cdot \left(\left(\frac{x}{y} \cdot \frac{x}{y}\right) \cdot 0.3333333333333333\right)\right)} + -1\right), -1\right)\\ \mathbf{elif}\;x \cdot x \leq 10^{+46}:\\ \;\;\;\;\frac{x \cdot x - y \cdot \left(y \cdot 4\right)}{x \cdot x + y \cdot \left(y \cdot 4\right)}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]
    11. Add Preprocessing

    Alternative 2: 78.9% accurate, 0.2× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := y \cdot \left(y \cdot 4\right)\\ \mathbf{if}\;x \cdot x \leq 10^{-167}:\\ \;\;\;\;\mathsf{fma}\left(0.5, \frac{x}{y} \cdot \frac{x}{y}, -1\right)\\ \mathbf{elif}\;x \cdot x \leq 10^{+46}:\\ \;\;\;\;\frac{x \cdot x - t\_0}{x \cdot x + t\_0}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
    (FPCore (x y)
     :precision binary64
     (let* ((t_0 (* y (* y 4.0))))
       (if (<= (* x x) 1e-167)
         (fma 0.5 (* (/ x y) (/ x y)) -1.0)
         (if (<= (* x x) 1e+46) (/ (- (* x x) t_0) (+ (* x x) t_0)) 1.0))))
    double code(double x, double y) {
    	double t_0 = y * (y * 4.0);
    	double tmp;
    	if ((x * x) <= 1e-167) {
    		tmp = fma(0.5, ((x / y) * (x / y)), -1.0);
    	} else if ((x * x) <= 1e+46) {
    		tmp = ((x * x) - t_0) / ((x * x) + t_0);
    	} else {
    		tmp = 1.0;
    	}
    	return tmp;
    }
    
    function code(x, y)
    	t_0 = Float64(y * Float64(y * 4.0))
    	tmp = 0.0
    	if (Float64(x * x) <= 1e-167)
    		tmp = fma(0.5, Float64(Float64(x / y) * Float64(x / y)), -1.0);
    	elseif (Float64(x * x) <= 1e+46)
    		tmp = Float64(Float64(Float64(x * x) - t_0) / Float64(Float64(x * x) + t_0));
    	else
    		tmp = 1.0;
    	end
    	return tmp
    end
    
    code[x_, y_] := Block[{t$95$0 = N[(y * N[(y * 4.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(x * x), $MachinePrecision], 1e-167], N[(0.5 * N[(N[(x / y), $MachinePrecision] * N[(x / y), $MachinePrecision]), $MachinePrecision] + -1.0), $MachinePrecision], If[LessEqual[N[(x * x), $MachinePrecision], 1e+46], N[(N[(N[(x * x), $MachinePrecision] - t$95$0), $MachinePrecision] / N[(N[(x * x), $MachinePrecision] + t$95$0), $MachinePrecision]), $MachinePrecision], 1.0]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := y \cdot \left(y \cdot 4\right)\\
    \mathbf{if}\;x \cdot x \leq 10^{-167}:\\
    \;\;\;\;\mathsf{fma}\left(0.5, \frac{x}{y} \cdot \frac{x}{y}, -1\right)\\
    
    \mathbf{elif}\;x \cdot x \leq 10^{+46}:\\
    \;\;\;\;\frac{x \cdot x - t\_0}{x \cdot x + t\_0}\\
    
    \mathbf{else}:\\
    \;\;\;\;1\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if (*.f64 x x) < 1e-167

      1. Initial program 55.2%

        \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
      2. Add Preprocessing
      3. Taylor expanded in x around 0 80.3%

        \[\leadsto \color{blue}{0.5 \cdot \frac{{x}^{2}}{{y}^{2}} - 1} \]
      4. Step-by-step derivation
        1. fma-neg80.3%

          \[\leadsto \color{blue}{\mathsf{fma}\left(0.5, \frac{{x}^{2}}{{y}^{2}}, -1\right)} \]
        2. unpow280.3%

          \[\leadsto \mathsf{fma}\left(0.5, \frac{\color{blue}{x \cdot x}}{{y}^{2}}, -1\right) \]
        3. unpow280.3%

          \[\leadsto \mathsf{fma}\left(0.5, \frac{x \cdot x}{\color{blue}{y \cdot y}}, -1\right) \]
        4. times-frac91.9%

          \[\leadsto \mathsf{fma}\left(0.5, \color{blue}{\frac{x}{y} \cdot \frac{x}{y}}, -1\right) \]
        5. metadata-eval91.9%

          \[\leadsto \mathsf{fma}\left(0.5, \frac{x}{y} \cdot \frac{x}{y}, \color{blue}{-1}\right) \]
      5. Simplified91.9%

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

      if 1e-167 < (*.f64 x x) < 9.9999999999999999e45

      1. Initial program 83.0%

        \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
      2. Add Preprocessing

      if 9.9999999999999999e45 < (*.f64 x x)

      1. Initial program 39.8%

        \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
      2. Add Preprocessing
      3. Taylor expanded in x around inf 82.6%

        \[\leadsto \color{blue}{1} \]
    3. Recombined 3 regimes into one program.
    4. Final simplification86.2%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \cdot x \leq 10^{-167}:\\ \;\;\;\;\mathsf{fma}\left(0.5, \frac{x}{y} \cdot \frac{x}{y}, -1\right)\\ \mathbf{elif}\;x \cdot x \leq 10^{+46}:\\ \;\;\;\;\frac{x \cdot x - y \cdot \left(y \cdot 4\right)}{x \cdot x + y \cdot \left(y \cdot 4\right)}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]
    5. Add Preprocessing

    Alternative 3: 78.6% accurate, 0.6× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} t_0 := y \cdot \left(y \cdot 4\right)\\ \mathbf{if}\;x \cdot x \leq 10^{-167}:\\ \;\;\;\;-1\\ \mathbf{elif}\;x \cdot x \leq 3.6 \cdot 10^{+50}:\\ \;\;\;\;\frac{x \cdot x - t\_0}{x \cdot x + t\_0}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
    (FPCore (x y)
     :precision binary64
     (let* ((t_0 (* y (* y 4.0))))
       (if (<= (* x x) 1e-167)
         -1.0
         (if (<= (* x x) 3.6e+50) (/ (- (* x x) t_0) (+ (* x x) t_0)) 1.0))))
    double code(double x, double y) {
    	double t_0 = y * (y * 4.0);
    	double tmp;
    	if ((x * x) <= 1e-167) {
    		tmp = -1.0;
    	} else if ((x * x) <= 3.6e+50) {
    		tmp = ((x * x) - t_0) / ((x * x) + t_0);
    	} else {
    		tmp = 1.0;
    	}
    	return tmp;
    }
    
    real(8) function code(x, y)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        real(8) :: t_0
        real(8) :: tmp
        t_0 = y * (y * 4.0d0)
        if ((x * x) <= 1d-167) then
            tmp = -1.0d0
        else if ((x * x) <= 3.6d+50) then
            tmp = ((x * x) - t_0) / ((x * x) + t_0)
        else
            tmp = 1.0d0
        end if
        code = tmp
    end function
    
    public static double code(double x, double y) {
    	double t_0 = y * (y * 4.0);
    	double tmp;
    	if ((x * x) <= 1e-167) {
    		tmp = -1.0;
    	} else if ((x * x) <= 3.6e+50) {
    		tmp = ((x * x) - t_0) / ((x * x) + t_0);
    	} else {
    		tmp = 1.0;
    	}
    	return tmp;
    }
    
    def code(x, y):
    	t_0 = y * (y * 4.0)
    	tmp = 0
    	if (x * x) <= 1e-167:
    		tmp = -1.0
    	elif (x * x) <= 3.6e+50:
    		tmp = ((x * x) - t_0) / ((x * x) + t_0)
    	else:
    		tmp = 1.0
    	return tmp
    
    function code(x, y)
    	t_0 = Float64(y * Float64(y * 4.0))
    	tmp = 0.0
    	if (Float64(x * x) <= 1e-167)
    		tmp = -1.0;
    	elseif (Float64(x * x) <= 3.6e+50)
    		tmp = Float64(Float64(Float64(x * x) - t_0) / Float64(Float64(x * x) + t_0));
    	else
    		tmp = 1.0;
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y)
    	t_0 = y * (y * 4.0);
    	tmp = 0.0;
    	if ((x * x) <= 1e-167)
    		tmp = -1.0;
    	elseif ((x * x) <= 3.6e+50)
    		tmp = ((x * x) - t_0) / ((x * x) + t_0);
    	else
    		tmp = 1.0;
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_] := Block[{t$95$0 = N[(y * N[(y * 4.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[N[(x * x), $MachinePrecision], 1e-167], -1.0, If[LessEqual[N[(x * x), $MachinePrecision], 3.6e+50], N[(N[(N[(x * x), $MachinePrecision] - t$95$0), $MachinePrecision] / N[(N[(x * x), $MachinePrecision] + t$95$0), $MachinePrecision]), $MachinePrecision], 1.0]]]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    t_0 := y \cdot \left(y \cdot 4\right)\\
    \mathbf{if}\;x \cdot x \leq 10^{-167}:\\
    \;\;\;\;-1\\
    
    \mathbf{elif}\;x \cdot x \leq 3.6 \cdot 10^{+50}:\\
    \;\;\;\;\frac{x \cdot x - t\_0}{x \cdot x + t\_0}\\
    
    \mathbf{else}:\\
    \;\;\;\;1\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 3 regimes
    2. if (*.f64 x x) < 1e-167

      1. Initial program 55.2%

        \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
      2. Add Preprocessing
      3. Taylor expanded in x around 0 91.1%

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

      if 1e-167 < (*.f64 x x) < 3.59999999999999986e50

      1. Initial program 83.0%

        \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
      2. Add Preprocessing

      if 3.59999999999999986e50 < (*.f64 x x)

      1. Initial program 39.8%

        \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
      2. Add Preprocessing
      3. Taylor expanded in x around inf 82.6%

        \[\leadsto \color{blue}{1} \]
    3. Recombined 3 regimes into one program.
    4. Final simplification85.8%

      \[\leadsto \begin{array}{l} \mathbf{if}\;x \cdot x \leq 10^{-167}:\\ \;\;\;\;-1\\ \mathbf{elif}\;x \cdot x \leq 3.6 \cdot 10^{+50}:\\ \;\;\;\;\frac{x \cdot x - y \cdot \left(y \cdot 4\right)}{x \cdot x + y \cdot \left(y \cdot 4\right)}\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \]
    5. Add Preprocessing

    Alternative 4: 74.4% accurate, 2.4× speedup?

    \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;x \cdot x \leq 5 \cdot 10^{-110}:\\ \;\;\;\;-1\\ \mathbf{else}:\\ \;\;\;\;1\\ \end{array} \end{array} \]
    (FPCore (x y) :precision binary64 (if (<= (* x x) 5e-110) -1.0 1.0))
    double code(double x, double y) {
    	double tmp;
    	if ((x * x) <= 5e-110) {
    		tmp = -1.0;
    	} 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 * x) <= 5d-110) then
            tmp = -1.0d0
        else
            tmp = 1.0d0
        end if
        code = tmp
    end function
    
    public static double code(double x, double y) {
    	double tmp;
    	if ((x * x) <= 5e-110) {
    		tmp = -1.0;
    	} else {
    		tmp = 1.0;
    	}
    	return tmp;
    }
    
    def code(x, y):
    	tmp = 0
    	if (x * x) <= 5e-110:
    		tmp = -1.0
    	else:
    		tmp = 1.0
    	return tmp
    
    function code(x, y)
    	tmp = 0.0
    	if (Float64(x * x) <= 5e-110)
    		tmp = -1.0;
    	else
    		tmp = 1.0;
    	end
    	return tmp
    end
    
    function tmp_2 = code(x, y)
    	tmp = 0.0;
    	if ((x * x) <= 5e-110)
    		tmp = -1.0;
    	else
    		tmp = 1.0;
    	end
    	tmp_2 = tmp;
    end
    
    code[x_, y_] := If[LessEqual[N[(x * x), $MachinePrecision], 5e-110], -1.0, 1.0]
    
    \begin{array}{l}
    
    \\
    \begin{array}{l}
    \mathbf{if}\;x \cdot x \leq 5 \cdot 10^{-110}:\\
    \;\;\;\;-1\\
    
    \mathbf{else}:\\
    \;\;\;\;1\\
    
    
    \end{array}
    \end{array}
    
    Derivation
    1. Split input into 2 regimes
    2. if (*.f64 x x) < 5e-110

      1. Initial program 60.4%

        \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
      2. Add Preprocessing
      3. Taylor expanded in x around 0 87.9%

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

      if 5e-110 < (*.f64 x x)

      1. Initial program 48.3%

        \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
      2. Add Preprocessing
      3. Taylor expanded in x around inf 76.9%

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

    Alternative 5: 50.6% accurate, 19.0× 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 53.5%

      \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
    2. Add Preprocessing
    3. Taylor expanded in x around 0 51.8%

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

    Developer target: 51.2% accurate, 0.1× 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 2024097 
    (FPCore (x y)
      :name "Diagrams.TwoD.Arc:arcBetween from diagrams-lib-1.3.0.3"
      :precision binary64
    
      :alt
      (if (< (/ (- (* x x) (* (* y 4.0) y)) (+ (* x x) (* (* y 4.0) y))) 0.9743233849626781) (- (/ (* x x) (+ (* x x) (* (* y y) 4.0))) (/ (* (* y y) 4.0) (+ (* x x) (* (* y y) 4.0)))) (- (pow (/ x (sqrt (+ (* x x) (* (* y y) 4.0)))) 2.0) (/ (* (* y y) 4.0) (+ (* x x) (* (* y y) 4.0)))))
    
      (/ (- (* x x) (* (* y 4.0) y)) (+ (* x x) (* (* y 4.0) y))))