Diagrams.TwoD.Apollonian:initialConfig from diagrams-contrib-1.3.0.5, A

Percentage Accurate: 68.7% → 99.9%
Time: 9.1s
Alternatives: 6
Speedup: 1.3×

Specification

?
\[\begin{array}{l} \\ \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0)))
double code(double x, double y, double z) {
	return (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = (((x * x) + (y * y)) - (z * z)) / (y * 2.0d0)
end function
public static double code(double x, double y, double z) {
	return (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
}
def code(x, y, z):
	return (((x * x) + (y * y)) - (z * z)) / (y * 2.0)
function code(x, y, z)
	return Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z * z)) / Float64(y * 2.0))
end
function tmp = code(x, y, z)
	tmp = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
end
code[x_, y_, z_] := N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z * z), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}
\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 6 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: 68.7% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0)))
double code(double x, double y, double z) {
	return (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = (((x * x) + (y * y)) - (z * z)) / (y * 2.0d0)
end function
public static double code(double x, double y, double z) {
	return (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
}
def code(x, y, z):
	return (((x * x) + (y * y)) - (z * z)) / (y * 2.0)
function code(x, y, z)
	return Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z * z)) / Float64(y * 2.0))
end
function tmp = code(x, y, z)
	tmp = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
end
code[x_, y_, z_] := N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z * z), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}
\end{array}

Alternative 1: 99.9% accurate, 1.3× speedup?

\[\begin{array}{l} \\ 0.5 \cdot \mathsf{fma}\left(z + x, \frac{x - z}{y}, y\right) \end{array} \]
(FPCore (x y z) :precision binary64 (* 0.5 (fma (+ z x) (/ (- x z) y) y)))
double code(double x, double y, double z) {
	return 0.5 * fma((z + x), ((x - z) / y), y);
}
function code(x, y, z)
	return Float64(0.5 * fma(Float64(z + x), Float64(Float64(x - z) / y), y))
end
code[x_, y_, z_] := N[(0.5 * N[(N[(z + x), $MachinePrecision] * N[(N[(x - z), $MachinePrecision] / y), $MachinePrecision] + y), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
0.5 \cdot \mathsf{fma}\left(z + x, \frac{x - z}{y}, y\right)
\end{array}
Derivation
  1. Initial program 70.7%

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

    \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{y}^{2} - {z}^{2}}{y} + \frac{1}{2} \cdot \frac{{x}^{2}}{y}} \]
  4. Step-by-step derivation
    1. distribute-lft-outN/A

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

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

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

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

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

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

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

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

      \[\leadsto \frac{1}{2} \cdot \left(\frac{{x}^{2}}{y} + \left(\left(\mathsf{neg}\left(\frac{{z}^{2}}{y}\right)\right) + y \cdot \color{blue}{1}\right)\right) \]
    10. *-rgt-identityN/A

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

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

      \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{\left(\frac{{x}^{2}}{y} - \frac{{z}^{2}}{y}\right)} + y\right) \]
    13. div-subN/A

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

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

      \[\leadsto \frac{1}{2} \cdot \left(\frac{x \cdot x - \color{blue}{z \cdot z}}{y} + y\right) \]
    16. difference-of-squaresN/A

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

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

      \[\leadsto \frac{1}{2} \cdot \color{blue}{\mathsf{fma}\left(x + z, \frac{x - z}{y}, y\right)} \]
  5. Applied rewrites99.9%

    \[\leadsto \color{blue}{0.5 \cdot \mathsf{fma}\left(z + x, \frac{x - z}{y}, y\right)} \]
  6. Add Preprocessing

Alternative 2: 38.3% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := z \cdot \left(z \cdot \frac{-0.5}{y}\right)\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq 0:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq 2 \cdot 10^{+153}:\\ \;\;\;\;0.5 \cdot y\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;x \cdot \left(x \cdot \frac{0.5}{y}\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (* z (* z (/ -0.5 y))))
        (t_1 (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0))))
   (if (<= t_1 0.0)
     t_0
     (if (<= t_1 2e+153)
       (* 0.5 y)
       (if (<= t_1 INFINITY) (* x (* x (/ 0.5 y))) t_0)))))
double code(double x, double y, double z) {
	double t_0 = z * (z * (-0.5 / y));
	double t_1 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
	double tmp;
	if (t_1 <= 0.0) {
		tmp = t_0;
	} else if (t_1 <= 2e+153) {
		tmp = 0.5 * y;
	} else if (t_1 <= ((double) INFINITY)) {
		tmp = x * (x * (0.5 / y));
	} else {
		tmp = t_0;
	}
	return tmp;
}
public static double code(double x, double y, double z) {
	double t_0 = z * (z * (-0.5 / y));
	double t_1 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
	double tmp;
	if (t_1 <= 0.0) {
		tmp = t_0;
	} else if (t_1 <= 2e+153) {
		tmp = 0.5 * y;
	} else if (t_1 <= Double.POSITIVE_INFINITY) {
		tmp = x * (x * (0.5 / y));
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x, y, z):
	t_0 = z * (z * (-0.5 / y))
	t_1 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0)
	tmp = 0
	if t_1 <= 0.0:
		tmp = t_0
	elif t_1 <= 2e+153:
		tmp = 0.5 * y
	elif t_1 <= math.inf:
		tmp = x * (x * (0.5 / y))
	else:
		tmp = t_0
	return tmp
function code(x, y, z)
	t_0 = Float64(z * Float64(z * Float64(-0.5 / y)))
	t_1 = Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z * z)) / Float64(y * 2.0))
	tmp = 0.0
	if (t_1 <= 0.0)
		tmp = t_0;
	elseif (t_1 <= 2e+153)
		tmp = Float64(0.5 * y);
	elseif (t_1 <= Inf)
		tmp = Float64(x * Float64(x * Float64(0.5 / y)));
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	t_0 = z * (z * (-0.5 / y));
	t_1 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
	tmp = 0.0;
	if (t_1 <= 0.0)
		tmp = t_0;
	elseif (t_1 <= 2e+153)
		tmp = 0.5 * y;
	elseif (t_1 <= Inf)
		tmp = x * (x * (0.5 / y));
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := Block[{t$95$0 = N[(z * N[(z * N[(-0.5 / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z * z), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, 0.0], t$95$0, If[LessEqual[t$95$1, 2e+153], N[(0.5 * y), $MachinePrecision], If[LessEqual[t$95$1, Infinity], N[(x * N[(x * N[(0.5 / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$0]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := z \cdot \left(z \cdot \frac{-0.5}{y}\right)\\
t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\
\mathbf{if}\;t\_1 \leq 0:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;t\_1 \leq 2 \cdot 10^{+153}:\\
\;\;\;\;0.5 \cdot y\\

\mathbf{elif}\;t\_1 \leq \infty:\\
\;\;\;\;x \cdot \left(x \cdot \frac{0.5}{y}\right)\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < 0.0 or +inf.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

    1. Initial program 66.9%

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

      \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
    4. Step-by-step derivation
      1. associate-*r/N/A

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

        \[\leadsto \frac{\color{blue}{\left(\frac{1}{2} \cdot -1\right)} \cdot {z}^{2}}{y} \]
      3. associate-*r*N/A

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

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

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(\mathsf{neg}\left({z}^{2}\right)\right)}{y}} \]
      6. mul-1-negN/A

        \[\leadsto \frac{\frac{1}{2} \cdot \color{blue}{\left(-1 \cdot {z}^{2}\right)}}{y} \]
      7. associate-*r*N/A

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

        \[\leadsto \frac{\color{blue}{\frac{-1}{2}} \cdot {z}^{2}}{y} \]
      9. *-commutativeN/A

        \[\leadsto \frac{\color{blue}{{z}^{2} \cdot \frac{-1}{2}}}{y} \]
      10. lower-*.f64N/A

        \[\leadsto \frac{\color{blue}{{z}^{2} \cdot \frac{-1}{2}}}{y} \]
      11. unpow2N/A

        \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot \frac{-1}{2}}{y} \]
      12. lower-*.f6434.8

        \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot -0.5}{y} \]
    5. Applied rewrites34.8%

      \[\leadsto \color{blue}{\frac{\left(z \cdot z\right) \cdot -0.5}{y}} \]
    6. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot \frac{-1}{2}}{y} \]
      2. associate-/l*N/A

        \[\leadsto \color{blue}{\left(z \cdot z\right) \cdot \frac{\frac{-1}{2}}{y}} \]
      3. *-commutativeN/A

        \[\leadsto \color{blue}{\frac{\frac{-1}{2}}{y} \cdot \left(z \cdot z\right)} \]
      4. clear-numN/A

        \[\leadsto \color{blue}{\frac{1}{\frac{y}{\frac{-1}{2}}}} \cdot \left(z \cdot z\right) \]
      5. div-invN/A

        \[\leadsto \frac{1}{\color{blue}{y \cdot \frac{1}{\frac{-1}{2}}}} \cdot \left(z \cdot z\right) \]
      6. metadata-evalN/A

        \[\leadsto \frac{1}{y \cdot \color{blue}{-2}} \cdot \left(z \cdot z\right) \]
      7. metadata-evalN/A

        \[\leadsto \frac{1}{y \cdot \color{blue}{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \left(z \cdot z\right) \]
      8. distribute-rgt-neg-inN/A

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

        \[\leadsto \frac{1}{\mathsf{neg}\left(\color{blue}{y \cdot 2}\right)} \cdot \left(z \cdot z\right) \]
      10. lift-*.f64N/A

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

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

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

        \[\leadsto \color{blue}{\left(\frac{1}{\mathsf{neg}\left(y \cdot 2\right)} \cdot z\right)} \cdot z \]
      14. lift-*.f64N/A

        \[\leadsto \left(\frac{1}{\mathsf{neg}\left(\color{blue}{y \cdot 2}\right)} \cdot z\right) \cdot z \]
      15. distribute-rgt-neg-inN/A

        \[\leadsto \left(\frac{1}{\color{blue}{y \cdot \left(\mathsf{neg}\left(2\right)\right)}} \cdot z\right) \cdot z \]
      16. metadata-evalN/A

        \[\leadsto \left(\frac{1}{y \cdot \color{blue}{-2}} \cdot z\right) \cdot z \]
      17. metadata-evalN/A

        \[\leadsto \left(\frac{1}{y \cdot \color{blue}{\frac{1}{\frac{-1}{2}}}} \cdot z\right) \cdot z \]
      18. div-invN/A

        \[\leadsto \left(\frac{1}{\color{blue}{\frac{y}{\frac{-1}{2}}}} \cdot z\right) \cdot z \]
      19. clear-numN/A

        \[\leadsto \left(\color{blue}{\frac{\frac{-1}{2}}{y}} \cdot z\right) \cdot z \]
      20. lower-/.f6438.0

        \[\leadsto \left(\color{blue}{\frac{-0.5}{y}} \cdot z\right) \cdot z \]
    7. Applied rewrites38.0%

      \[\leadsto \color{blue}{\left(\frac{-0.5}{y} \cdot z\right) \cdot z} \]

    if 0.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < 2e153

    1. Initial program 97.2%

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

      \[\leadsto \color{blue}{\frac{1}{2} \cdot y} \]
    4. Step-by-step derivation
      1. lower-*.f6471.9

        \[\leadsto \color{blue}{0.5 \cdot y} \]
    5. Applied rewrites71.9%

      \[\leadsto \color{blue}{0.5 \cdot y} \]

    if 2e153 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < +inf.0

    1. Initial program 68.5%

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

      \[\leadsto \frac{\color{blue}{{x}^{2}}}{y \cdot 2} \]
    4. Step-by-step derivation
      1. unpow2N/A

        \[\leadsto \frac{\color{blue}{x \cdot x}}{y \cdot 2} \]
      2. lower-*.f6433.4

        \[\leadsto \frac{\color{blue}{x \cdot x}}{y \cdot 2} \]
    5. Applied rewrites33.4%

      \[\leadsto \frac{\color{blue}{x \cdot x}}{y \cdot 2} \]
    6. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\color{blue}{x \cdot x}}{y \cdot 2} \]
      2. lift-*.f64N/A

        \[\leadsto \frac{x \cdot x}{\color{blue}{y \cdot 2}} \]
      3. clear-numN/A

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

        \[\leadsto \color{blue}{\frac{1}{y \cdot 2} \cdot \left(x \cdot x\right)} \]
      5. lift-*.f64N/A

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

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

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

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

        \[\leadsto \left(\frac{1}{\color{blue}{y \cdot 2}} \cdot x\right) \cdot x \]
      10. *-commutativeN/A

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

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

        \[\leadsto \left(\frac{\color{blue}{\frac{1}{2}}}{y} \cdot x\right) \cdot x \]
      13. lower-/.f6435.4

        \[\leadsto \left(\color{blue}{\frac{0.5}{y}} \cdot x\right) \cdot x \]
    7. Applied rewrites35.4%

      \[\leadsto \color{blue}{\left(\frac{0.5}{y} \cdot x\right) \cdot x} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification40.8%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 0:\\ \;\;\;\;z \cdot \left(z \cdot \frac{-0.5}{y}\right)\\ \mathbf{elif}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 2 \cdot 10^{+153}:\\ \;\;\;\;0.5 \cdot y\\ \mathbf{elif}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq \infty:\\ \;\;\;\;x \cdot \left(x \cdot \frac{0.5}{y}\right)\\ \mathbf{else}:\\ \;\;\;\;z \cdot \left(z \cdot \frac{-0.5}{y}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 67.5% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \left(z - x\right) \cdot \left(\left(z + x\right) \cdot \frac{-0.5}{y}\right)\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq 0:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (* (- z x) (* (+ z x) (/ -0.5 y))))
        (t_1 (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0))))
   (if (<= t_1 0.0) t_0 (if (<= t_1 INFINITY) (* 0.5 (fma x (/ x y) y)) t_0))))
double code(double x, double y, double z) {
	double t_0 = (z - x) * ((z + x) * (-0.5 / y));
	double t_1 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
	double tmp;
	if (t_1 <= 0.0) {
		tmp = t_0;
	} else if (t_1 <= ((double) INFINITY)) {
		tmp = 0.5 * fma(x, (x / y), y);
	} else {
		tmp = t_0;
	}
	return tmp;
}
function code(x, y, z)
	t_0 = Float64(Float64(z - x) * Float64(Float64(z + x) * Float64(-0.5 / y)))
	t_1 = Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z * z)) / Float64(y * 2.0))
	tmp = 0.0
	if (t_1 <= 0.0)
		tmp = t_0;
	elseif (t_1 <= Inf)
		tmp = Float64(0.5 * fma(x, Float64(x / y), y));
	else
		tmp = t_0;
	end
	return tmp
end
code[x_, y_, z_] := Block[{t$95$0 = N[(N[(z - x), $MachinePrecision] * N[(N[(z + x), $MachinePrecision] * N[(-0.5 / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z * z), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, 0.0], t$95$0, If[LessEqual[t$95$1, Infinity], N[(0.5 * N[(x * N[(x / y), $MachinePrecision] + y), $MachinePrecision]), $MachinePrecision], t$95$0]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \left(z - x\right) \cdot \left(\left(z + x\right) \cdot \frac{-0.5}{y}\right)\\
t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\
\mathbf{if}\;t\_1 \leq 0:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;t\_1 \leq \infty:\\
\;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < 0.0 or +inf.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

    1. Initial program 66.9%

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

      \[\leadsto \frac{\color{blue}{{x}^{2} - {z}^{2}}}{y \cdot 2} \]
    4. Step-by-step derivation
      1. unpow2N/A

        \[\leadsto \frac{\color{blue}{x \cdot x} - {z}^{2}}{y \cdot 2} \]
      2. unpow2N/A

        \[\leadsto \frac{x \cdot x - \color{blue}{z \cdot z}}{y \cdot 2} \]
      3. difference-of-squaresN/A

        \[\leadsto \frac{\color{blue}{\left(x + z\right) \cdot \left(x - z\right)}}{y \cdot 2} \]
      4. lower-*.f64N/A

        \[\leadsto \frac{\color{blue}{\left(x + z\right) \cdot \left(x - z\right)}}{y \cdot 2} \]
      5. +-commutativeN/A

        \[\leadsto \frac{\color{blue}{\left(z + x\right)} \cdot \left(x - z\right)}{y \cdot 2} \]
      6. lower-+.f64N/A

        \[\leadsto \frac{\color{blue}{\left(z + x\right)} \cdot \left(x - z\right)}{y \cdot 2} \]
      7. lower--.f6464.6

        \[\leadsto \frac{\left(z + x\right) \cdot \color{blue}{\left(x - z\right)}}{y \cdot 2} \]
    5. Applied rewrites64.6%

      \[\leadsto \frac{\color{blue}{\left(z + x\right) \cdot \left(x - z\right)}}{y \cdot 2} \]
    6. Step-by-step derivation
      1. lift-+.f64N/A

        \[\leadsto \frac{\color{blue}{\left(z + x\right)} \cdot \left(x - z\right)}{y \cdot 2} \]
      2. lift--.f64N/A

        \[\leadsto \frac{\left(z + x\right) \cdot \color{blue}{\left(x - z\right)}}{y \cdot 2} \]
      3. lift-*.f64N/A

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

        \[\leadsto \frac{\color{blue}{\mathsf{neg}\left(\left(\mathsf{neg}\left(\left(z + x\right) \cdot \left(x - z\right)\right)\right)\right)}}{y \cdot 2} \]
      5. lift-*.f64N/A

        \[\leadsto \frac{\mathsf{neg}\left(\left(\mathsf{neg}\left(\left(z + x\right) \cdot \left(x - z\right)\right)\right)\right)}{\color{blue}{y \cdot 2}} \]
      6. remove-double-negN/A

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

        \[\leadsto \color{blue}{\frac{\mathsf{neg}\left(\left(z + x\right) \cdot \left(x - z\right)\right)}{\mathsf{neg}\left(y \cdot 2\right)}} \]
      8. div-invN/A

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

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

        \[\leadsto \left(\mathsf{neg}\left(\color{blue}{\left(x - z\right) \cdot \left(z + x\right)}\right)\right) \cdot \frac{1}{\mathsf{neg}\left(y \cdot 2\right)} \]
      11. distribute-lft-neg-inN/A

        \[\leadsto \color{blue}{\left(\left(\mathsf{neg}\left(\left(x - z\right)\right)\right) \cdot \left(z + x\right)\right)} \cdot \frac{1}{\mathsf{neg}\left(y \cdot 2\right)} \]
      12. lift--.f64N/A

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

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

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

        \[\leadsto \left(\left(\mathsf{neg}\left(\color{blue}{\left(\left(\mathsf{neg}\left(z\right)\right) + x\right)}\right)\right) \cdot \left(z + x\right)\right) \cdot \frac{1}{\mathsf{neg}\left(y \cdot 2\right)} \]
      16. distribute-neg-inN/A

        \[\leadsto \left(\color{blue}{\left(\left(\mathsf{neg}\left(\left(\mathsf{neg}\left(z\right)\right)\right)\right) + \left(\mathsf{neg}\left(x\right)\right)\right)} \cdot \left(z + x\right)\right) \cdot \frac{1}{\mathsf{neg}\left(y \cdot 2\right)} \]
      17. lift-neg.f64N/A

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

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

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

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

        \[\leadsto \color{blue}{\left(z - x\right) \cdot \left(\left(z + x\right) \cdot \frac{1}{\mathsf{neg}\left(y \cdot 2\right)}\right)} \]
    7. Applied rewrites69.2%

      \[\leadsto \color{blue}{\left(z - x\right) \cdot \left(\left(z + x\right) \cdot \frac{-0.5}{y}\right)} \]

    if 0.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < +inf.0

    1. Initial program 75.4%

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

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

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

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

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

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

        \[\leadsto \frac{1}{2} \cdot \frac{{y}^{2} \cdot \frac{{x}^{2}}{{y}^{2}} + \color{blue}{{y}^{2} \cdot 1}}{y} \]
      6. distribute-lft-inN/A

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

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

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

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

        \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{\left(y \cdot \frac{y}{y}\right)} \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)\right) \]
      11. *-inversesN/A

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{2} \cdot \left(y + \frac{{x}^{2}}{\color{blue}{y \cdot \frac{y}{y}}}\right) \]
      19. *-inversesN/A

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

        \[\leadsto \frac{1}{2} \cdot \left(y + \frac{{x}^{2}}{\color{blue}{y}}\right) \]
    5. Applied rewrites66.4%

      \[\leadsto \color{blue}{0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 4: 34.7% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := z \cdot \left(z \cdot \frac{-0.5}{y}\right)\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq 0:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;0.5 \cdot y\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (* z (* z (/ -0.5 y))))
        (t_1 (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0))))
   (if (<= t_1 0.0) t_0 (if (<= t_1 INFINITY) (* 0.5 y) t_0))))
double code(double x, double y, double z) {
	double t_0 = z * (z * (-0.5 / y));
	double t_1 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
	double tmp;
	if (t_1 <= 0.0) {
		tmp = t_0;
	} else if (t_1 <= ((double) INFINITY)) {
		tmp = 0.5 * y;
	} else {
		tmp = t_0;
	}
	return tmp;
}
public static double code(double x, double y, double z) {
	double t_0 = z * (z * (-0.5 / y));
	double t_1 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
	double tmp;
	if (t_1 <= 0.0) {
		tmp = t_0;
	} else if (t_1 <= Double.POSITIVE_INFINITY) {
		tmp = 0.5 * y;
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x, y, z):
	t_0 = z * (z * (-0.5 / y))
	t_1 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0)
	tmp = 0
	if t_1 <= 0.0:
		tmp = t_0
	elif t_1 <= math.inf:
		tmp = 0.5 * y
	else:
		tmp = t_0
	return tmp
function code(x, y, z)
	t_0 = Float64(z * Float64(z * Float64(-0.5 / y)))
	t_1 = Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z * z)) / Float64(y * 2.0))
	tmp = 0.0
	if (t_1 <= 0.0)
		tmp = t_0;
	elseif (t_1 <= Inf)
		tmp = Float64(0.5 * y);
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x, y, z)
	t_0 = z * (z * (-0.5 / y));
	t_1 = (((x * x) + (y * y)) - (z * z)) / (y * 2.0);
	tmp = 0.0;
	if (t_1 <= 0.0)
		tmp = t_0;
	elseif (t_1 <= Inf)
		tmp = 0.5 * y;
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := Block[{t$95$0 = N[(z * N[(z * N[(-0.5 / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z * z), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[t$95$1, 0.0], t$95$0, If[LessEqual[t$95$1, Infinity], N[(0.5 * y), $MachinePrecision], t$95$0]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := z \cdot \left(z \cdot \frac{-0.5}{y}\right)\\
t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\
\mathbf{if}\;t\_1 \leq 0:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;t\_1 \leq \infty:\\
\;\;\;\;0.5 \cdot y\\

\mathbf{else}:\\
\;\;\;\;t\_0\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < 0.0 or +inf.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

    1. Initial program 66.9%

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

      \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
    4. Step-by-step derivation
      1. associate-*r/N/A

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

        \[\leadsto \frac{\color{blue}{\left(\frac{1}{2} \cdot -1\right)} \cdot {z}^{2}}{y} \]
      3. associate-*r*N/A

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

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

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(\mathsf{neg}\left({z}^{2}\right)\right)}{y}} \]
      6. mul-1-negN/A

        \[\leadsto \frac{\frac{1}{2} \cdot \color{blue}{\left(-1 \cdot {z}^{2}\right)}}{y} \]
      7. associate-*r*N/A

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

        \[\leadsto \frac{\color{blue}{\frac{-1}{2}} \cdot {z}^{2}}{y} \]
      9. *-commutativeN/A

        \[\leadsto \frac{\color{blue}{{z}^{2} \cdot \frac{-1}{2}}}{y} \]
      10. lower-*.f64N/A

        \[\leadsto \frac{\color{blue}{{z}^{2} \cdot \frac{-1}{2}}}{y} \]
      11. unpow2N/A

        \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot \frac{-1}{2}}{y} \]
      12. lower-*.f6434.8

        \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot -0.5}{y} \]
    5. Applied rewrites34.8%

      \[\leadsto \color{blue}{\frac{\left(z \cdot z\right) \cdot -0.5}{y}} \]
    6. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot \frac{-1}{2}}{y} \]
      2. associate-/l*N/A

        \[\leadsto \color{blue}{\left(z \cdot z\right) \cdot \frac{\frac{-1}{2}}{y}} \]
      3. *-commutativeN/A

        \[\leadsto \color{blue}{\frac{\frac{-1}{2}}{y} \cdot \left(z \cdot z\right)} \]
      4. clear-numN/A

        \[\leadsto \color{blue}{\frac{1}{\frac{y}{\frac{-1}{2}}}} \cdot \left(z \cdot z\right) \]
      5. div-invN/A

        \[\leadsto \frac{1}{\color{blue}{y \cdot \frac{1}{\frac{-1}{2}}}} \cdot \left(z \cdot z\right) \]
      6. metadata-evalN/A

        \[\leadsto \frac{1}{y \cdot \color{blue}{-2}} \cdot \left(z \cdot z\right) \]
      7. metadata-evalN/A

        \[\leadsto \frac{1}{y \cdot \color{blue}{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \left(z \cdot z\right) \]
      8. distribute-rgt-neg-inN/A

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

        \[\leadsto \frac{1}{\mathsf{neg}\left(\color{blue}{y \cdot 2}\right)} \cdot \left(z \cdot z\right) \]
      10. lift-*.f64N/A

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

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

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

        \[\leadsto \color{blue}{\left(\frac{1}{\mathsf{neg}\left(y \cdot 2\right)} \cdot z\right)} \cdot z \]
      14. lift-*.f64N/A

        \[\leadsto \left(\frac{1}{\mathsf{neg}\left(\color{blue}{y \cdot 2}\right)} \cdot z\right) \cdot z \]
      15. distribute-rgt-neg-inN/A

        \[\leadsto \left(\frac{1}{\color{blue}{y \cdot \left(\mathsf{neg}\left(2\right)\right)}} \cdot z\right) \cdot z \]
      16. metadata-evalN/A

        \[\leadsto \left(\frac{1}{y \cdot \color{blue}{-2}} \cdot z\right) \cdot z \]
      17. metadata-evalN/A

        \[\leadsto \left(\frac{1}{y \cdot \color{blue}{\frac{1}{\frac{-1}{2}}}} \cdot z\right) \cdot z \]
      18. div-invN/A

        \[\leadsto \left(\frac{1}{\color{blue}{\frac{y}{\frac{-1}{2}}}} \cdot z\right) \cdot z \]
      19. clear-numN/A

        \[\leadsto \left(\color{blue}{\frac{\frac{-1}{2}}{y}} \cdot z\right) \cdot z \]
      20. lower-/.f6438.0

        \[\leadsto \left(\color{blue}{\frac{-0.5}{y}} \cdot z\right) \cdot z \]
    7. Applied rewrites38.0%

      \[\leadsto \color{blue}{\left(\frac{-0.5}{y} \cdot z\right) \cdot z} \]

    if 0.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < +inf.0

    1. Initial program 75.4%

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

      \[\leadsto \color{blue}{\frac{1}{2} \cdot y} \]
    4. Step-by-step derivation
      1. lower-*.f6439.9

        \[\leadsto \color{blue}{0.5 \cdot y} \]
    5. Applied rewrites39.9%

      \[\leadsto \color{blue}{0.5 \cdot y} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification38.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 0:\\ \;\;\;\;z \cdot \left(z \cdot \frac{-0.5}{y}\right)\\ \mathbf{elif}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq \infty:\\ \;\;\;\;0.5 \cdot y\\ \mathbf{else}:\\ \;\;\;\;z \cdot \left(z \cdot \frac{-0.5}{y}\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 5: 49.6% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 0:\\ \;\;\;\;z \cdot \left(z \cdot \frac{-0.5}{y}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (<= (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0)) 0.0)
   (* z (* z (/ -0.5 y)))
   (* 0.5 (fma x (/ x y) y))))
double code(double x, double y, double z) {
	double tmp;
	if (((((x * x) + (y * y)) - (z * z)) / (y * 2.0)) <= 0.0) {
		tmp = z * (z * (-0.5 / y));
	} else {
		tmp = 0.5 * fma(x, (x / y), y);
	}
	return tmp;
}
function code(x, y, z)
	tmp = 0.0
	if (Float64(Float64(Float64(Float64(x * x) + Float64(y * y)) - Float64(z * z)) / Float64(y * 2.0)) <= 0.0)
		tmp = Float64(z * Float64(z * Float64(-0.5 / y)));
	else
		tmp = Float64(0.5 * fma(x, Float64(x / y), y));
	end
	return tmp
end
code[x_, y_, z_] := If[LessEqual[N[(N[(N[(N[(x * x), $MachinePrecision] + N[(y * y), $MachinePrecision]), $MachinePrecision] - N[(z * z), $MachinePrecision]), $MachinePrecision] / N[(y * 2.0), $MachinePrecision]), $MachinePrecision], 0.0], N[(z * N[(z * N[(-0.5 / y), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], N[(0.5 * N[(x * N[(x / y), $MachinePrecision] + y), $MachinePrecision]), $MachinePrecision]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 0:\\
\;\;\;\;z \cdot \left(z \cdot \frac{-0.5}{y}\right)\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < 0.0

    1. Initial program 80.7%

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

      \[\leadsto \color{blue}{\frac{-1}{2} \cdot \frac{{z}^{2}}{y}} \]
    4. Step-by-step derivation
      1. associate-*r/N/A

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

        \[\leadsto \frac{\color{blue}{\left(\frac{1}{2} \cdot -1\right)} \cdot {z}^{2}}{y} \]
      3. associate-*r*N/A

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

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

        \[\leadsto \color{blue}{\frac{\frac{1}{2} \cdot \left(\mathsf{neg}\left({z}^{2}\right)\right)}{y}} \]
      6. mul-1-negN/A

        \[\leadsto \frac{\frac{1}{2} \cdot \color{blue}{\left(-1 \cdot {z}^{2}\right)}}{y} \]
      7. associate-*r*N/A

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

        \[\leadsto \frac{\color{blue}{\frac{-1}{2}} \cdot {z}^{2}}{y} \]
      9. *-commutativeN/A

        \[\leadsto \frac{\color{blue}{{z}^{2} \cdot \frac{-1}{2}}}{y} \]
      10. lower-*.f64N/A

        \[\leadsto \frac{\color{blue}{{z}^{2} \cdot \frac{-1}{2}}}{y} \]
      11. unpow2N/A

        \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot \frac{-1}{2}}{y} \]
      12. lower-*.f6432.2

        \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot -0.5}{y} \]
    5. Applied rewrites32.2%

      \[\leadsto \color{blue}{\frac{\left(z \cdot z\right) \cdot -0.5}{y}} \]
    6. Step-by-step derivation
      1. lift-*.f64N/A

        \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot \frac{-1}{2}}{y} \]
      2. associate-/l*N/A

        \[\leadsto \color{blue}{\left(z \cdot z\right) \cdot \frac{\frac{-1}{2}}{y}} \]
      3. *-commutativeN/A

        \[\leadsto \color{blue}{\frac{\frac{-1}{2}}{y} \cdot \left(z \cdot z\right)} \]
      4. clear-numN/A

        \[\leadsto \color{blue}{\frac{1}{\frac{y}{\frac{-1}{2}}}} \cdot \left(z \cdot z\right) \]
      5. div-invN/A

        \[\leadsto \frac{1}{\color{blue}{y \cdot \frac{1}{\frac{-1}{2}}}} \cdot \left(z \cdot z\right) \]
      6. metadata-evalN/A

        \[\leadsto \frac{1}{y \cdot \color{blue}{-2}} \cdot \left(z \cdot z\right) \]
      7. metadata-evalN/A

        \[\leadsto \frac{1}{y \cdot \color{blue}{\left(\mathsf{neg}\left(2\right)\right)}} \cdot \left(z \cdot z\right) \]
      8. distribute-rgt-neg-inN/A

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

        \[\leadsto \frac{1}{\mathsf{neg}\left(\color{blue}{y \cdot 2}\right)} \cdot \left(z \cdot z\right) \]
      10. lift-*.f64N/A

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

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

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

        \[\leadsto \color{blue}{\left(\frac{1}{\mathsf{neg}\left(y \cdot 2\right)} \cdot z\right)} \cdot z \]
      14. lift-*.f64N/A

        \[\leadsto \left(\frac{1}{\mathsf{neg}\left(\color{blue}{y \cdot 2}\right)} \cdot z\right) \cdot z \]
      15. distribute-rgt-neg-inN/A

        \[\leadsto \left(\frac{1}{\color{blue}{y \cdot \left(\mathsf{neg}\left(2\right)\right)}} \cdot z\right) \cdot z \]
      16. metadata-evalN/A

        \[\leadsto \left(\frac{1}{y \cdot \color{blue}{-2}} \cdot z\right) \cdot z \]
      17. metadata-evalN/A

        \[\leadsto \left(\frac{1}{y \cdot \color{blue}{\frac{1}{\frac{-1}{2}}}} \cdot z\right) \cdot z \]
      18. div-invN/A

        \[\leadsto \left(\frac{1}{\color{blue}{\frac{y}{\frac{-1}{2}}}} \cdot z\right) \cdot z \]
      19. clear-numN/A

        \[\leadsto \left(\color{blue}{\frac{\frac{-1}{2}}{y}} \cdot z\right) \cdot z \]
      20. lower-/.f6434.7

        \[\leadsto \left(\color{blue}{\frac{-0.5}{y}} \cdot z\right) \cdot z \]
    7. Applied rewrites34.7%

      \[\leadsto \color{blue}{\left(\frac{-0.5}{y} \cdot z\right) \cdot z} \]

    if 0.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

    1. Initial program 62.5%

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

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

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

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

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

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

        \[\leadsto \frac{1}{2} \cdot \frac{{y}^{2} \cdot \frac{{x}^{2}}{{y}^{2}} + \color{blue}{{y}^{2} \cdot 1}}{y} \]
      6. distribute-lft-inN/A

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

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

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

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

        \[\leadsto \frac{1}{2} \cdot \left(\color{blue}{\left(y \cdot \frac{y}{y}\right)} \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)\right) \]
      11. *-inversesN/A

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{2} \cdot \left(y + \frac{{x}^{2}}{\color{blue}{y \cdot \frac{y}{y}}}\right) \]
      19. *-inversesN/A

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

        \[\leadsto \frac{1}{2} \cdot \left(y + \frac{{x}^{2}}{\color{blue}{y}}\right) \]
    5. Applied rewrites62.9%

      \[\leadsto \color{blue}{0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification50.1%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 0:\\ \;\;\;\;z \cdot \left(z \cdot \frac{-0.5}{y}\right)\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\ \end{array} \]
  5. Add Preprocessing

Alternative 6: 34.5% accurate, 6.3× speedup?

\[\begin{array}{l} \\ 0.5 \cdot y \end{array} \]
(FPCore (x y z) :precision binary64 (* 0.5 y))
double code(double x, double y, double z) {
	return 0.5 * y;
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = 0.5d0 * y
end function
public static double code(double x, double y, double z) {
	return 0.5 * y;
}
def code(x, y, z):
	return 0.5 * y
function code(x, y, z)
	return Float64(0.5 * y)
end
function tmp = code(x, y, z)
	tmp = 0.5 * y;
end
code[x_, y_, z_] := N[(0.5 * y), $MachinePrecision]
\begin{array}{l}

\\
0.5 \cdot y
\end{array}
Derivation
  1. Initial program 70.7%

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

    \[\leadsto \color{blue}{\frac{1}{2} \cdot y} \]
  4. Step-by-step derivation
    1. lower-*.f6436.0

      \[\leadsto \color{blue}{0.5 \cdot y} \]
  5. Applied rewrites36.0%

    \[\leadsto \color{blue}{0.5 \cdot y} \]
  6. Add Preprocessing

Developer Target 1: 99.9% accurate, 1.1× speedup?

\[\begin{array}{l} \\ y \cdot 0.5 - \left(\frac{0.5}{y} \cdot \left(z + x\right)\right) \cdot \left(z - x\right) \end{array} \]
(FPCore (x y z)
 :precision binary64
 (- (* y 0.5) (* (* (/ 0.5 y) (+ z x)) (- z x))))
double code(double x, double y, double z) {
	return (y * 0.5) - (((0.5 / y) * (z + x)) * (z - x));
}
real(8) function code(x, y, z)
    real(8), intent (in) :: x
    real(8), intent (in) :: y
    real(8), intent (in) :: z
    code = (y * 0.5d0) - (((0.5d0 / y) * (z + x)) * (z - x))
end function
public static double code(double x, double y, double z) {
	return (y * 0.5) - (((0.5 / y) * (z + x)) * (z - x));
}
def code(x, y, z):
	return (y * 0.5) - (((0.5 / y) * (z + x)) * (z - x))
function code(x, y, z)
	return Float64(Float64(y * 0.5) - Float64(Float64(Float64(0.5 / y) * Float64(z + x)) * Float64(z - x)))
end
function tmp = code(x, y, z)
	tmp = (y * 0.5) - (((0.5 / y) * (z + x)) * (z - x));
end
code[x_, y_, z_] := N[(N[(y * 0.5), $MachinePrecision] - N[(N[(N[(0.5 / y), $MachinePrecision] * N[(z + x), $MachinePrecision]), $MachinePrecision] * N[(z - x), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
y \cdot 0.5 - \left(\frac{0.5}{y} \cdot \left(z + x\right)\right) \cdot \left(z - x\right)
\end{array}

Reproduce

?
herbie shell --seed 2024219 
(FPCore (x y z)
  :name "Diagrams.TwoD.Apollonian:initialConfig from diagrams-contrib-1.3.0.5, A"
  :precision binary64

  :alt
  (! :herbie-platform default (- (* y 1/2) (* (* (/ 1/2 y) (+ z x)) (- z x))))

  (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0)))