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

Percentage Accurate: 68.6% → 99.9%
Time: 10.1s
Alternatives: 7
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 7 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: 68.6% 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 66.8%

    \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
  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. Applied rewrites99.9%

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

Alternative 2: 40.1% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := z \cdot \frac{z \cdot -0.5}{y}\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq -5 \cdot 10^{-66}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq 4 \cdot 10^{+151}:\\ \;\;\;\;0.5 \cdot y\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;x \cdot \frac{x}{y \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(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 -5e-66)
     t_0
     (if (<= t_1 4e+151)
       (* 0.5 y)
       (if (<= t_1 INFINITY) (* x (/ x (* y 2.0))) 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 <= -5e-66) {
		tmp = t_0;
	} else if (t_1 <= 4e+151) {
		tmp = 0.5 * y;
	} else if (t_1 <= ((double) INFINITY)) {
		tmp = x * (x / (y * 2.0));
	} 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 <= -5e-66) {
		tmp = t_0;
	} else if (t_1 <= 4e+151) {
		tmp = 0.5 * y;
	} else if (t_1 <= Double.POSITIVE_INFINITY) {
		tmp = x * (x / (y * 2.0));
	} 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 <= -5e-66:
		tmp = t_0
	elif t_1 <= 4e+151:
		tmp = 0.5 * y
	elif t_1 <= math.inf:
		tmp = x * (x / (y * 2.0))
	else:
		tmp = t_0
	return tmp
function code(x, y, z)
	t_0 = Float64(z * Float64(Float64(z * -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 <= -5e-66)
		tmp = t_0;
	elseif (t_1 <= 4e+151)
		tmp = Float64(0.5 * y);
	elseif (t_1 <= Inf)
		tmp = Float64(x * Float64(x / Float64(y * 2.0)));
	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 <= -5e-66)
		tmp = t_0;
	elseif (t_1 <= 4e+151)
		tmp = 0.5 * y;
	elseif (t_1 <= Inf)
		tmp = x * (x / (y * 2.0));
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x_, y_, z_] := Block[{t$95$0 = N[(z * N[(N[(z * -0.5), $MachinePrecision] / y), $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, -5e-66], t$95$0, If[LessEqual[t$95$1, 4e+151], N[(0.5 * y), $MachinePrecision], If[LessEqual[t$95$1, Infinity], N[(x * N[(x / N[(y * 2.0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$0]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := z \cdot \frac{z \cdot -0.5}{y}\\
t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\
\mathbf{if}\;t\_1 \leq -5 \cdot 10^{-66}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;t\_1 \leq 4 \cdot 10^{+151}:\\
\;\;\;\;0.5 \cdot y\\

\mathbf{elif}\;t\_1 \leq \infty:\\
\;\;\;\;x \cdot \frac{x}{y \cdot 2}\\

\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))) < -4.99999999999999962e-66 or +inf.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

    1. Initial program 63.1%

      \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
    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-*.f6430.1

        \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot -0.5}{y} \]
    5. Applied rewrites30.1%

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

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

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

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

        \[\leadsto z \cdot \color{blue}{\frac{z \cdot \frac{-1}{2}}{y}} \]
      5. lower-*.f6433.7

        \[\leadsto z \cdot \frac{\color{blue}{z \cdot -0.5}}{y} \]
    7. Applied rewrites33.7%

      \[\leadsto \color{blue}{z \cdot \frac{z \cdot -0.5}{y}} \]

    if -4.99999999999999962e-66 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < 4.00000000000000007e151

    1. Initial program 84.5%

      \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
    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-*.f6461.5

        \[\leadsto \color{blue}{0.5 \cdot y} \]
    5. Applied rewrites61.5%

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

    if 4.00000000000000007e151 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < +inf.0

    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 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-*.f6432.9

        \[\leadsto \frac{\color{blue}{x \cdot x}}{y \cdot 2} \]
    5. Applied rewrites32.9%

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

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

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

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

        \[\leadsto \color{blue}{\frac{x}{y \cdot 2} \cdot x} \]
      5. lower-/.f6436.6

        \[\leadsto \color{blue}{\frac{x}{y \cdot 2}} \cdot x \]
    7. Applied rewrites36.6%

      \[\leadsto \color{blue}{\frac{x}{y \cdot 2} \cdot x} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification37.9%

    \[\leadsto \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq -5 \cdot 10^{-66}:\\ \;\;\;\;z \cdot \frac{z \cdot -0.5}{y}\\ \mathbf{elif}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq 4 \cdot 10^{+151}:\\ \;\;\;\;0.5 \cdot y\\ \mathbf{elif}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq \infty:\\ \;\;\;\;x \cdot \frac{x}{y \cdot 2}\\ \mathbf{else}:\\ \;\;\;\;z \cdot \frac{z \cdot -0.5}{y}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 39.3% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := z \cdot \frac{z \cdot -0.5}{y}\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq -5 \cdot 10^{-66}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq 4 \cdot 10^{+151}:\\ \;\;\;\;0.5 \cdot y\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;\left(x \cdot x\right) \cdot \frac{0.5}{y}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(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 -5e-66)
     t_0
     (if (<= t_1 4e+151)
       (* 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 <= -5e-66) {
		tmp = t_0;
	} else if (t_1 <= 4e+151) {
		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 <= -5e-66) {
		tmp = t_0;
	} else if (t_1 <= 4e+151) {
		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 <= -5e-66:
		tmp = t_0
	elif t_1 <= 4e+151:
		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(Float64(z * -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 <= -5e-66)
		tmp = t_0;
	elseif (t_1 <= 4e+151)
		tmp = Float64(0.5 * y);
	elseif (t_1 <= Inf)
		tmp = Float64(Float64(x * 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 <= -5e-66)
		tmp = t_0;
	elseif (t_1 <= 4e+151)
		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[(N[(z * -0.5), $MachinePrecision] / y), $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, -5e-66], t$95$0, If[LessEqual[t$95$1, 4e+151], N[(0.5 * y), $MachinePrecision], If[LessEqual[t$95$1, Infinity], N[(N[(x * x), $MachinePrecision] * N[(0.5 / y), $MachinePrecision]), $MachinePrecision], t$95$0]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := z \cdot \frac{z \cdot -0.5}{y}\\
t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\
\mathbf{if}\;t\_1 \leq -5 \cdot 10^{-66}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;t\_1 \leq 4 \cdot 10^{+151}:\\
\;\;\;\;0.5 \cdot y\\

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

\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))) < -4.99999999999999962e-66 or +inf.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

    1. Initial program 63.1%

      \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
    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-*.f6430.1

        \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot -0.5}{y} \]
    5. Applied rewrites30.1%

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

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

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

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

        \[\leadsto z \cdot \color{blue}{\frac{z \cdot \frac{-1}{2}}{y}} \]
      5. lower-*.f6433.7

        \[\leadsto z \cdot \frac{\color{blue}{z \cdot -0.5}}{y} \]
    7. Applied rewrites33.7%

      \[\leadsto \color{blue}{z \cdot \frac{z \cdot -0.5}{y}} \]

    if -4.99999999999999962e-66 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < 4.00000000000000007e151

    1. Initial program 84.5%

      \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
    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-*.f6461.5

        \[\leadsto \color{blue}{0.5 \cdot y} \]
    5. Applied rewrites61.5%

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

    if 4.00000000000000007e151 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < +inf.0

    1. Initial program 66.9%

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(y + z, y - z, x \cdot x\right) \cdot \color{blue}{\frac{\frac{1}{2}}{y}} \]
    4. Applied rewrites66.8%

      \[\leadsto \color{blue}{\mathsf{fma}\left(y + z, y - z, x \cdot x\right) \cdot \frac{0.5}{y}} \]
    5. Taylor expanded in x around inf

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

        \[\leadsto \color{blue}{\left(x \cdot x\right)} \cdot \frac{\frac{1}{2}}{y} \]
      2. lower-*.f6432.9

        \[\leadsto \color{blue}{\left(x \cdot x\right)} \cdot \frac{0.5}{y} \]
    7. Applied rewrites32.9%

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

Alternative 4: 68.5% accurate, 0.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{x - z}{y} \cdot \left(0.5 \cdot \left(z + x\right)\right)\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq 0:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (let* ((t_0 (* (/ (- x z) y) (* 0.5 (+ z x))))
        (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 = ((x - z) / y) * (0.5 * (z + x));
	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(Float64(x - z) / y) * Float64(0.5 * Float64(z + x)))
	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[(N[(x - z), $MachinePrecision] / y), $MachinePrecision] * N[(0.5 * N[(z + x), $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 := \frac{x - z}{y} \cdot \left(0.5 \cdot \left(z + x\right)\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 61.5%

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

      \[\leadsto \color{blue}{\frac{1}{2} \cdot \frac{{y}^{2} - {z}^{2}}{y} + \frac{1}{2} \cdot \frac{{x}^{2}}{y}} \]
    4. Applied rewrites99.9%

      \[\leadsto \color{blue}{0.5 \cdot \mathsf{fma}\left(z + x, \frac{x - z}{y}, y\right)} \]
    5. Taylor expanded in y around 0

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

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

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(\frac{1}{2} \cdot \left(x + z\right)\right) \cdot \color{blue}{\frac{x - z}{y}} \]
      15. lower--.f6466.7

        \[\leadsto \left(0.5 \cdot \left(x + z\right)\right) \cdot \frac{\color{blue}{x - z}}{y} \]
    7. Applied rewrites66.7%

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

    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 75.3%

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{{y}^{2} \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)}}{y} \]
      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 rewrites68.9%

      \[\leadsto \color{blue}{0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)} \]
  3. Recombined 2 regimes into one program.
  4. Final simplification67.6%

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

Alternative 5: 36.8% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := z \cdot \frac{z \cdot -0.5}{y}\\ t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\ \mathbf{if}\;t\_1 \leq -5 \cdot 10^{-66}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;t\_1 \leq \infty:\\ \;\;\;\;0.5 \cdot y\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(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 -5e-66) 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 <= -5e-66) {
		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 <= -5e-66) {
		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 <= -5e-66:
		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(Float64(z * -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 <= -5e-66)
		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 <= -5e-66)
		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[(N[(z * -0.5), $MachinePrecision] / y), $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, -5e-66], 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 \frac{z \cdot -0.5}{y}\\
t_1 := \frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2}\\
\mathbf{if}\;t\_1 \leq -5 \cdot 10^{-66}:\\
\;\;\;\;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))) < -4.99999999999999962e-66 or +inf.0 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

    1. Initial program 63.1%

      \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
    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-*.f6430.1

        \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot -0.5}{y} \]
    5. Applied rewrites30.1%

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

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

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

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

        \[\leadsto z \cdot \color{blue}{\frac{z \cdot \frac{-1}{2}}{y}} \]
      5. lower-*.f6433.7

        \[\leadsto z \cdot \frac{\color{blue}{z \cdot -0.5}}{y} \]
    7. Applied rewrites33.7%

      \[\leadsto \color{blue}{z \cdot \frac{z \cdot -0.5}{y}} \]

    if -4.99999999999999962e-66 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64))) < +inf.0

    1. Initial program 72.1%

      \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
    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-*.f6439.6

        \[\leadsto \color{blue}{0.5 \cdot y} \]
    5. Applied rewrites39.6%

      \[\leadsto \color{blue}{0.5 \cdot y} \]
  3. Recombined 2 regimes into one program.
  4. Add Preprocessing

Alternative 6: 51.3% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \leq -5 \cdot 10^{-66}:\\ \;\;\;\;z \cdot \frac{z \cdot -0.5}{y}\\ \mathbf{else}:\\ \;\;\;\;0.5 \cdot \mathsf{fma}\left(x, \frac{x}{y}, y\right)\\ \end{array} \end{array} \]
(FPCore (x y z)
 :precision binary64
 (if (<= (/ (- (+ (* x x) (* y y)) (* z z)) (* y 2.0)) -5e-66)
   (* 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)) <= -5e-66) {
		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)) <= -5e-66)
		tmp = Float64(z * Float64(Float64(z * -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], -5e-66], N[(z * N[(N[(z * -0.5), $MachinePrecision] / y), $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 -5 \cdot 10^{-66}:\\
\;\;\;\;z \cdot \frac{z \cdot -0.5}{y}\\

\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))) < -4.99999999999999962e-66

    1. Initial program 78.6%

      \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
    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-*.f6427.5

        \[\leadsto \frac{\color{blue}{\left(z \cdot z\right)} \cdot -0.5}{y} \]
    5. Applied rewrites27.5%

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

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

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

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

        \[\leadsto z \cdot \color{blue}{\frac{z \cdot \frac{-1}{2}}{y}} \]
      5. lower-*.f6429.7

        \[\leadsto z \cdot \frac{\color{blue}{z \cdot -0.5}}{y} \]
    7. Applied rewrites29.7%

      \[\leadsto \color{blue}{z \cdot \frac{z \cdot -0.5}{y}} \]

    if -4.99999999999999962e-66 < (/.f64 (-.f64 (+.f64 (*.f64 x x) (*.f64 y y)) (*.f64 z z)) (*.f64 y #s(literal 2 binary64)))

    1. Initial program 56.0%

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

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

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

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

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

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

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

        \[\leadsto \frac{1}{2} \cdot \frac{\color{blue}{{y}^{2} \cdot \left(1 + \frac{{x}^{2}}{{y}^{2}}\right)}}{y} \]
      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 rewrites65.3%

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

Alternative 7: 34.3% 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 66.8%

    \[\frac{\left(x \cdot x + y \cdot y\right) - z \cdot z}{y \cdot 2} \]
  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-*.f6436.4

      \[\leadsto \color{blue}{0.5 \cdot y} \]
  5. Applied rewrites36.4%

    \[\leadsto \color{blue}{0.5 \cdot y} \]
  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 2024216 
(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)))