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

Percentage Accurate: 50.6% → 79.0%
Time: 3.7s
Alternatives: 4
Speedup: 2.8×

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 4 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: 50.6% 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: 79.0% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(4 \cdot y\right) \cdot y\\ t_1 := \frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{\mathsf{fma}\left(4 \cdot y, y, x \cdot x\right)}\\ \mathbf{if}\;t\_0 \leq 5 \cdot 10^{-239}:\\ \;\;\;\;1\\ \mathbf{elif}\;t\_0 \leq 2 \cdot 10^{-59}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;t\_0 \leq 400000000:\\ \;\;\;\;1\\ \mathbf{elif}\;t\_0 \leq 2 \cdot 10^{+179}:\\ \;\;\;\;t\_1\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{0.5 \cdot x}{y}, \frac{x}{y}, -1\right)\\ \end{array} \end{array} \]
(FPCore (x y)
 :precision binary64
 (let* ((t_0 (* (* 4.0 y) y))
        (t_1 (/ (fma -4.0 (* y y) (* x x)) (fma (* 4.0 y) y (* x x)))))
   (if (<= t_0 5e-239)
     1.0
     (if (<= t_0 2e-59)
       t_1
       (if (<= t_0 400000000.0)
         1.0
         (if (<= t_0 2e+179) t_1 (fma (/ (* 0.5 x) y) (/ x y) -1.0)))))))
double code(double x, double y) {
	double t_0 = (4.0 * y) * y;
	double t_1 = fma(-4.0, (y * y), (x * x)) / fma((4.0 * y), y, (x * x));
	double tmp;
	if (t_0 <= 5e-239) {
		tmp = 1.0;
	} else if (t_0 <= 2e-59) {
		tmp = t_1;
	} else if (t_0 <= 400000000.0) {
		tmp = 1.0;
	} else if (t_0 <= 2e+179) {
		tmp = t_1;
	} else {
		tmp = fma(((0.5 * x) / y), (x / y), -1.0);
	}
	return tmp;
}
function code(x, y)
	t_0 = Float64(Float64(4.0 * y) * y)
	t_1 = Float64(fma(-4.0, Float64(y * y), Float64(x * x)) / fma(Float64(4.0 * y), y, Float64(x * x)))
	tmp = 0.0
	if (t_0 <= 5e-239)
		tmp = 1.0;
	elseif (t_0 <= 2e-59)
		tmp = t_1;
	elseif (t_0 <= 400000000.0)
		tmp = 1.0;
	elseif (t_0 <= 2e+179)
		tmp = t_1;
	else
		tmp = fma(Float64(Float64(0.5 * x) / y), Float64(x / y), -1.0);
	end
	return tmp
end
code[x_, y_] := Block[{t$95$0 = N[(N[(4.0 * y), $MachinePrecision] * y), $MachinePrecision]}, Block[{t$95$1 = N[(N[(-4.0 * N[(y * y), $MachinePrecision] + N[(x * x), $MachinePrecision]), $MachinePrecision] / N[(N[(4.0 * y), $MachinePrecision] * y + N[(x * x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$0, 5e-239], 1.0, If[LessEqual[t$95$0, 2e-59], t$95$1, If[LessEqual[t$95$0, 400000000.0], 1.0, If[LessEqual[t$95$0, 2e+179], t$95$1, N[(N[(N[(0.5 * x), $MachinePrecision] / y), $MachinePrecision] * N[(x / y), $MachinePrecision] + -1.0), $MachinePrecision]]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(4 \cdot y\right) \cdot y\\
t_1 := \frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{\mathsf{fma}\left(4 \cdot y, y, x \cdot x\right)}\\
\mathbf{if}\;t\_0 \leq 5 \cdot 10^{-239}:\\
\;\;\;\;1\\

\mathbf{elif}\;t\_0 \leq 2 \cdot 10^{-59}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;t\_0 \leq 400000000:\\
\;\;\;\;1\\

\mathbf{elif}\;t\_0 \leq 2 \cdot 10^{+179}:\\
\;\;\;\;t\_1\\

\mathbf{else}:\\
\;\;\;\;\mathsf{fma}\left(\frac{0.5 \cdot x}{y}, \frac{x}{y}, -1\right)\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (*.f64 (*.f64 y #s(literal 4 binary64)) y) < 5e-239 or 2.0000000000000001e-59 < (*.f64 (*.f64 y #s(literal 4 binary64)) y) < 4e8

    1. Initial program 55.5%

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

      \[\leadsto \color{blue}{1} \]
    4. Step-by-step derivation
      1. Applied rewrites89.1%

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

      if 5e-239 < (*.f64 (*.f64 y #s(literal 4 binary64)) y) < 2.0000000000000001e-59 or 4e8 < (*.f64 (*.f64 y #s(literal 4 binary64)) y) < 1.99999999999999996e179

      1. Initial program 74.3%

        \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
      2. Add Preprocessing
      3. 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-*.f6474.3

          \[\leadsto \frac{\mathsf{fma}\left(-4, \color{blue}{y \cdot y}, x \cdot x\right)}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
        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. lower-fma.f6474.3

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

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

          \[\leadsto \frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{\mathsf{fma}\left(\color{blue}{4 \cdot y}, y, x \cdot x\right)} \]
        18. lower-*.f6474.3

          \[\leadsto \frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{\mathsf{fma}\left(\color{blue}{4 \cdot y}, y, x \cdot x\right)} \]
      4. Applied rewrites74.3%

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

      if 1.99999999999999996e179 < (*.f64 (*.f64 y #s(literal 4 binary64)) y)

      1. Initial program 19.5%

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

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

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

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

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

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

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

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

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

          \[\leadsto \mathsf{fma}\left(\frac{\frac{1}{2}}{y}, \frac{\color{blue}{x \cdot x}}{y}, \mathsf{neg}\left(1\right)\right) \]
        10. metadata-eval83.1

          \[\leadsto \mathsf{fma}\left(\frac{0.5}{y}, \frac{x \cdot x}{y}, \color{blue}{-1}\right) \]
      5. Applied rewrites83.1%

        \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{0.5}{y}, \frac{x \cdot x}{y}, -1\right)} \]
      6. Step-by-step derivation
        1. Applied rewrites92.4%

          \[\leadsto \mathsf{fma}\left(\frac{0.5 \cdot x}{y}, \color{blue}{\frac{x}{y}}, -1\right) \]
      7. Recombined 3 regimes into one program.
      8. Final simplification86.2%

        \[\leadsto \begin{array}{l} \mathbf{if}\;\left(4 \cdot y\right) \cdot y \leq 5 \cdot 10^{-239}:\\ \;\;\;\;1\\ \mathbf{elif}\;\left(4 \cdot y\right) \cdot y \leq 2 \cdot 10^{-59}:\\ \;\;\;\;\frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{\mathsf{fma}\left(4 \cdot y, y, x \cdot x\right)}\\ \mathbf{elif}\;\left(4 \cdot y\right) \cdot y \leq 400000000:\\ \;\;\;\;1\\ \mathbf{elif}\;\left(4 \cdot y\right) \cdot y \leq 2 \cdot 10^{+179}:\\ \;\;\;\;\frac{\mathsf{fma}\left(-4, y \cdot y, x \cdot x\right)}{\mathsf{fma}\left(4 \cdot y, y, x \cdot x\right)}\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{0.5 \cdot x}{y}, \frac{x}{y}, -1\right)\\ \end{array} \]
      9. Add Preprocessing

      Alternative 2: 75.1% accurate, 1.0× speedup?

      \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\left(4 \cdot y\right) \cdot y \leq 400000000:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{0.5 \cdot x}{y}, \frac{x}{y}, -1\right)\\ \end{array} \end{array} \]
      (FPCore (x y)
       :precision binary64
       (if (<= (* (* 4.0 y) y) 400000000.0) 1.0 (fma (/ (* 0.5 x) y) (/ x y) -1.0)))
      double code(double x, double y) {
      	double tmp;
      	if (((4.0 * y) * y) <= 400000000.0) {
      		tmp = 1.0;
      	} else {
      		tmp = fma(((0.5 * x) / y), (x / y), -1.0);
      	}
      	return tmp;
      }
      
      function code(x, y)
      	tmp = 0.0
      	if (Float64(Float64(4.0 * y) * y) <= 400000000.0)
      		tmp = 1.0;
      	else
      		tmp = fma(Float64(Float64(0.5 * x) / y), Float64(x / y), -1.0);
      	end
      	return tmp
      end
      
      code[x_, y_] := If[LessEqual[N[(N[(4.0 * y), $MachinePrecision] * y), $MachinePrecision], 400000000.0], 1.0, N[(N[(N[(0.5 * x), $MachinePrecision] / y), $MachinePrecision] * N[(x / y), $MachinePrecision] + -1.0), $MachinePrecision]]
      
      \begin{array}{l}
      
      \\
      \begin{array}{l}
      \mathbf{if}\;\left(4 \cdot y\right) \cdot y \leq 400000000:\\
      \;\;\;\;1\\
      
      \mathbf{else}:\\
      \;\;\;\;\mathsf{fma}\left(\frac{0.5 \cdot x}{y}, \frac{x}{y}, -1\right)\\
      
      
      \end{array}
      \end{array}
      
      Derivation
      1. Split input into 2 regimes
      2. if (*.f64 (*.f64 y #s(literal 4 binary64)) y) < 4e8

        1. Initial program 62.6%

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

          \[\leadsto \color{blue}{1} \]
        4. Step-by-step derivation
          1. Applied rewrites78.8%

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

          if 4e8 < (*.f64 (*.f64 y #s(literal 4 binary64)) y)

          1. Initial program 31.6%

            \[\frac{x \cdot x - \left(y \cdot 4\right) \cdot y}{x \cdot x + \left(y \cdot 4\right) \cdot y} \]
          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. associate-*r/N/A

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

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

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

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

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

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

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

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

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

            \[\leadsto \color{blue}{\mathsf{fma}\left(\frac{0.5}{y}, \frac{x \cdot x}{y}, -1\right)} \]
          6. Step-by-step derivation
            1. Applied rewrites82.0%

              \[\leadsto \mathsf{fma}\left(\frac{0.5 \cdot x}{y}, \color{blue}{\frac{x}{y}}, -1\right) \]
          7. Recombined 2 regimes into one program.
          8. Final simplification80.3%

            \[\leadsto \begin{array}{l} \mathbf{if}\;\left(4 \cdot y\right) \cdot y \leq 400000000:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;\mathsf{fma}\left(\frac{0.5 \cdot x}{y}, \frac{x}{y}, -1\right)\\ \end{array} \]
          9. Add Preprocessing

          Alternative 3: 74.6% accurate, 2.8× speedup?

          \[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\left(4 \cdot y\right) \cdot y \leq 400000000:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;-1\\ \end{array} \end{array} \]
          (FPCore (x y)
           :precision binary64
           (if (<= (* (* 4.0 y) y) 400000000.0) 1.0 -1.0))
          double code(double x, double y) {
          	double tmp;
          	if (((4.0 * y) * y) <= 400000000.0) {
          		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 (((4.0d0 * y) * y) <= 400000000.0d0) 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 (((4.0 * y) * y) <= 400000000.0) {
          		tmp = 1.0;
          	} else {
          		tmp = -1.0;
          	}
          	return tmp;
          }
          
          def code(x, y):
          	tmp = 0
          	if ((4.0 * y) * y) <= 400000000.0:
          		tmp = 1.0
          	else:
          		tmp = -1.0
          	return tmp
          
          function code(x, y)
          	tmp = 0.0
          	if (Float64(Float64(4.0 * y) * y) <= 400000000.0)
          		tmp = 1.0;
          	else
          		tmp = -1.0;
          	end
          	return tmp
          end
          
          function tmp_2 = code(x, y)
          	tmp = 0.0;
          	if (((4.0 * y) * y) <= 400000000.0)
          		tmp = 1.0;
          	else
          		tmp = -1.0;
          	end
          	tmp_2 = tmp;
          end
          
          code[x_, y_] := If[LessEqual[N[(N[(4.0 * y), $MachinePrecision] * y), $MachinePrecision], 400000000.0], 1.0, -1.0]
          
          \begin{array}{l}
          
          \\
          \begin{array}{l}
          \mathbf{if}\;\left(4 \cdot y\right) \cdot y \leq 400000000:\\
          \;\;\;\;1\\
          
          \mathbf{else}:\\
          \;\;\;\;-1\\
          
          
          \end{array}
          \end{array}
          
          Derivation
          1. Split input into 2 regimes
          2. if (*.f64 (*.f64 y #s(literal 4 binary64)) y) < 4e8

            1. Initial program 62.6%

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

              \[\leadsto \color{blue}{1} \]
            4. Step-by-step derivation
              1. Applied rewrites78.8%

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

              if 4e8 < (*.f64 (*.f64 y #s(literal 4 binary64)) y)

              1. Initial program 31.6%

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

                \[\leadsto \color{blue}{-1} \]
              4. Step-by-step derivation
                1. Applied rewrites81.5%

                  \[\leadsto \color{blue}{-1} \]
              5. Recombined 2 regimes into one program.
              6. Final simplification80.0%

                \[\leadsto \begin{array}{l} \mathbf{if}\;\left(4 \cdot y\right) \cdot y \leq 400000000:\\ \;\;\;\;1\\ \mathbf{else}:\\ \;\;\;\;-1\\ \end{array} \]
              7. Add Preprocessing

              Alternative 4: 49.8% accurate, 48.0× 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 48.4%

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

                \[\leadsto \color{blue}{-1} \]
              4. Step-by-step derivation
                1. Applied rewrites49.3%

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

                Developer Target 1: 51.1% 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 2024308 
                (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))))