_divideComplex, real part

Percentage Accurate: 61.4% → 82.2%
Time: 8.7s
Alternatives: 7
Speedup: 1.6×

Specification

?
\[\begin{array}{l} \\ \frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (/ (+ (* x.re y.re) (* x.im y.im)) (+ (* y.re y.re) (* y.im y.im))))
double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	return ((x_46_re * y_46_re) + (x_46_im * y_46_im)) / ((y_46_re * y_46_re) + (y_46_im * y_46_im));
}
real(8) function code(x_46re, x_46im, y_46re, y_46im)
    real(8), intent (in) :: x_46re
    real(8), intent (in) :: x_46im
    real(8), intent (in) :: y_46re
    real(8), intent (in) :: y_46im
    code = ((x_46re * y_46re) + (x_46im * y_46im)) / ((y_46re * y_46re) + (y_46im * y_46im))
end function
public static double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	return ((x_46_re * y_46_re) + (x_46_im * y_46_im)) / ((y_46_re * y_46_re) + (y_46_im * y_46_im));
}
def code(x_46_re, x_46_im, y_46_re, y_46_im):
	return ((x_46_re * y_46_re) + (x_46_im * y_46_im)) / ((y_46_re * y_46_re) + (y_46_im * y_46_im))
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	return Float64(Float64(Float64(x_46_re * y_46_re) + Float64(x_46_im * y_46_im)) / Float64(Float64(y_46_re * y_46_re) + Float64(y_46_im * y_46_im)))
end
function tmp = code(x_46_re, x_46_im, y_46_re, y_46_im)
	tmp = ((x_46_re * y_46_re) + (x_46_im * y_46_im)) / ((y_46_re * y_46_re) + (y_46_im * y_46_im));
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := N[(N[(N[(x$46$re * y$46$re), $MachinePrecision] + N[(x$46$im * y$46$im), $MachinePrecision]), $MachinePrecision] / N[(N[(y$46$re * y$46$re), $MachinePrecision] + N[(y$46$im * y$46$im), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im}
\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: 61.4% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (/ (+ (* x.re y.re) (* x.im y.im)) (+ (* y.re y.re) (* y.im y.im))))
double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	return ((x_46_re * y_46_re) + (x_46_im * y_46_im)) / ((y_46_re * y_46_re) + (y_46_im * y_46_im));
}
real(8) function code(x_46re, x_46im, y_46re, y_46im)
    real(8), intent (in) :: x_46re
    real(8), intent (in) :: x_46im
    real(8), intent (in) :: y_46re
    real(8), intent (in) :: y_46im
    code = ((x_46re * y_46re) + (x_46im * y_46im)) / ((y_46re * y_46re) + (y_46im * y_46im))
end function
public static double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	return ((x_46_re * y_46_re) + (x_46_im * y_46_im)) / ((y_46_re * y_46_re) + (y_46_im * y_46_im));
}
def code(x_46_re, x_46_im, y_46_re, y_46_im):
	return ((x_46_re * y_46_re) + (x_46_im * y_46_im)) / ((y_46_re * y_46_re) + (y_46_im * y_46_im))
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	return Float64(Float64(Float64(x_46_re * y_46_re) + Float64(x_46_im * y_46_im)) / Float64(Float64(y_46_re * y_46_re) + Float64(y_46_im * y_46_im)))
end
function tmp = code(x_46_re, x_46_im, y_46_re, y_46_im)
	tmp = ((x_46_re * y_46_re) + (x_46_im * y_46_im)) / ((y_46_re * y_46_re) + (y_46_im * y_46_im));
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := N[(N[(N[(x$46$re * y$46$re), $MachinePrecision] + N[(x$46$im * y$46$im), $MachinePrecision]), $MachinePrecision] / N[(N[(y$46$re * y$46$re), $MachinePrecision] + N[(y$46$im * y$46$im), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]
\begin{array}{l}

\\
\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im}
\end{array}

Alternative 1: 82.2% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{y.re \cdot y.re + y.im \cdot y.im}\\ t_1 := \frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}\\ \mathbf{if}\;y.re \leq -1.35 \cdot 10^{+126}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;y.re \leq -8 \cdot 10^{-117}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y.re \leq 1.6 \cdot 10^{-154}:\\ \;\;\;\;\frac{x.im + \frac{\mathsf{fma}\left(x.im, \frac{y.re \cdot \left(-y.re\right)}{y.im}, y.re \cdot x.re\right)}{y.im}}{y.im}\\ \mathbf{elif}\;y.re \leq 5.5 \cdot 10^{+59}:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (let* ((t_0 (/ (fma y.im x.im (* y.re x.re)) (+ (* y.re y.re) (* y.im y.im))))
        (t_1 (/ (fma x.im (/ y.im y.re) x.re) y.re)))
   (if (<= y.re -1.35e+126)
     t_1
     (if (<= y.re -8e-117)
       t_0
       (if (<= y.re 1.6e-154)
         (/
          (+ x.im (/ (fma x.im (/ (* y.re (- y.re)) y.im) (* y.re x.re)) y.im))
          y.im)
         (if (<= y.re 5.5e+59) t_0 t_1))))))
double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	double t_0 = fma(y_46_im, x_46_im, (y_46_re * x_46_re)) / ((y_46_re * y_46_re) + (y_46_im * y_46_im));
	double t_1 = fma(x_46_im, (y_46_im / y_46_re), x_46_re) / y_46_re;
	double tmp;
	if (y_46_re <= -1.35e+126) {
		tmp = t_1;
	} else if (y_46_re <= -8e-117) {
		tmp = t_0;
	} else if (y_46_re <= 1.6e-154) {
		tmp = (x_46_im + (fma(x_46_im, ((y_46_re * -y_46_re) / y_46_im), (y_46_re * x_46_re)) / y_46_im)) / y_46_im;
	} else if (y_46_re <= 5.5e+59) {
		tmp = t_0;
	} else {
		tmp = t_1;
	}
	return tmp;
}
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	t_0 = Float64(fma(y_46_im, x_46_im, Float64(y_46_re * x_46_re)) / Float64(Float64(y_46_re * y_46_re) + Float64(y_46_im * y_46_im)))
	t_1 = Float64(fma(x_46_im, Float64(y_46_im / y_46_re), x_46_re) / y_46_re)
	tmp = 0.0
	if (y_46_re <= -1.35e+126)
		tmp = t_1;
	elseif (y_46_re <= -8e-117)
		tmp = t_0;
	elseif (y_46_re <= 1.6e-154)
		tmp = Float64(Float64(x_46_im + Float64(fma(x_46_im, Float64(Float64(y_46_re * Float64(-y_46_re)) / y_46_im), Float64(y_46_re * x_46_re)) / y_46_im)) / y_46_im);
	elseif (y_46_re <= 5.5e+59)
		tmp = t_0;
	else
		tmp = t_1;
	end
	return tmp
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := Block[{t$95$0 = N[(N[(y$46$im * x$46$im + N[(y$46$re * x$46$re), $MachinePrecision]), $MachinePrecision] / N[(N[(y$46$re * y$46$re), $MachinePrecision] + N[(y$46$im * y$46$im), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(x$46$im * N[(y$46$im / y$46$re), $MachinePrecision] + x$46$re), $MachinePrecision] / y$46$re), $MachinePrecision]}, If[LessEqual[y$46$re, -1.35e+126], t$95$1, If[LessEqual[y$46$re, -8e-117], t$95$0, If[LessEqual[y$46$re, 1.6e-154], N[(N[(x$46$im + N[(N[(x$46$im * N[(N[(y$46$re * (-y$46$re)), $MachinePrecision] / y$46$im), $MachinePrecision] + N[(y$46$re * x$46$re), $MachinePrecision]), $MachinePrecision] / y$46$im), $MachinePrecision]), $MachinePrecision] / y$46$im), $MachinePrecision], If[LessEqual[y$46$re, 5.5e+59], t$95$0, t$95$1]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{y.re \cdot y.re + y.im \cdot y.im}\\
t_1 := \frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}\\
\mathbf{if}\;y.re \leq -1.35 \cdot 10^{+126}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;y.re \leq -8 \cdot 10^{-117}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y.re \leq 1.6 \cdot 10^{-154}:\\
\;\;\;\;\frac{x.im + \frac{\mathsf{fma}\left(x.im, \frac{y.re \cdot \left(-y.re\right)}{y.im}, y.re \cdot x.re\right)}{y.im}}{y.im}\\

\mathbf{elif}\;y.re \leq 5.5 \cdot 10^{+59}:\\
\;\;\;\;t\_0\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y.re < -1.35000000000000001e126 or 5.4999999999999999e59 < y.re

    1. Initial program 48.7%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \color{blue}{\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}} \]
      2. +-commutativeN/A

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

        \[\leadsto \frac{\color{blue}{x.im \cdot \frac{y.im}{y.re}} + x.re}{y.re} \]
      4. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}}{y.re} \]
      5. /-lowering-/.f6486.8

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \color{blue}{\frac{y.im}{y.re}}, x.re\right)}{y.re} \]
    5. Simplified86.8%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}} \]

    if -1.35000000000000001e126 < y.re < -8.00000000000000024e-117 or 1.60000000000000002e-154 < y.re < 5.4999999999999999e59

    1. Initial program 84.7%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. +-commutativeN/A

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

        \[\leadsto \frac{\color{blue}{y.im \cdot x.im} + x.re \cdot y.re}{y.re \cdot y.re + y.im \cdot y.im} \]
      3. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(y.im, x.im, x.re \cdot y.re\right)}}{y.re \cdot y.re + y.im \cdot y.im} \]
      4. *-lowering-*.f6484.7

        \[\leadsto \frac{\mathsf{fma}\left(y.im, x.im, \color{blue}{x.re \cdot y.re}\right)}{y.re \cdot y.re + y.im \cdot y.im} \]
    4. Applied egg-rr84.7%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(y.im, x.im, x.re \cdot y.re\right)}}{y.re \cdot y.re + y.im \cdot y.im} \]

    if -8.00000000000000024e-117 < y.re < 1.60000000000000002e-154

    1. Initial program 72.4%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Taylor expanded in y.im around inf

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

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

        \[\leadsto \frac{x.im + \left(\frac{x.re \cdot y.re}{y.im} + \color{blue}{\left(\mathsf{neg}\left(\frac{x.im \cdot {y.re}^{2}}{{y.im}^{2}}\right)\right)}\right)}{y.im} \]
      3. unsub-negN/A

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

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

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

        \[\leadsto \frac{x.im + \color{blue}{\frac{x.re \cdot y.re - \frac{x.im \cdot {y.re}^{2}}{y.im}}{y.im}}}{y.im} \]
      7. unsub-negN/A

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

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

        \[\leadsto \frac{x.im + \frac{\color{blue}{-1 \cdot \frac{x.im \cdot {y.re}^{2}}{y.im} + x.re \cdot y.re}}{y.im}}{y.im} \]
      10. /-lowering-/.f64N/A

        \[\leadsto \color{blue}{\frac{x.im + \frac{-1 \cdot \frac{x.im \cdot {y.re}^{2}}{y.im} + x.re \cdot y.re}{y.im}}{y.im}} \]
    5. Simplified94.1%

      \[\leadsto \color{blue}{\frac{x.im + \frac{\mathsf{fma}\left(x.im, \frac{y.re \cdot \left(-y.re\right)}{y.im}, x.re \cdot y.re\right)}{y.im}}{y.im}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification88.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y.re \leq -1.35 \cdot 10^{+126}:\\ \;\;\;\;\frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}\\ \mathbf{elif}\;y.re \leq -8 \cdot 10^{-117}:\\ \;\;\;\;\frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{y.re \cdot y.re + y.im \cdot y.im}\\ \mathbf{elif}\;y.re \leq 1.6 \cdot 10^{-154}:\\ \;\;\;\;\frac{x.im + \frac{\mathsf{fma}\left(x.im, \frac{y.re \cdot \left(-y.re\right)}{y.im}, y.re \cdot x.re\right)}{y.im}}{y.im}\\ \mathbf{elif}\;y.re \leq 5.5 \cdot 10^{+59}:\\ \;\;\;\;\frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{y.re \cdot y.re + y.im \cdot y.im}\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}\\ \end{array} \]
  5. Add Preprocessing

Alternative 2: 82.3% accurate, 0.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{y.re \cdot y.re + y.im \cdot y.im}\\ t_1 := \frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}\\ \mathbf{if}\;y.re \leq -6.1 \cdot 10^{+122}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;y.re \leq -2.8 \cdot 10^{-116}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y.re \leq 8.2 \cdot 10^{-157}:\\ \;\;\;\;\frac{\mathsf{fma}\left(x.re, \frac{y.re}{y.im}, x.im\right)}{y.im}\\ \mathbf{elif}\;y.re \leq 5.5 \cdot 10^{+59}:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (let* ((t_0 (/ (fma y.im x.im (* y.re x.re)) (+ (* y.re y.re) (* y.im y.im))))
        (t_1 (/ (fma x.im (/ y.im y.re) x.re) y.re)))
   (if (<= y.re -6.1e+122)
     t_1
     (if (<= y.re -2.8e-116)
       t_0
       (if (<= y.re 8.2e-157)
         (/ (fma x.re (/ y.re y.im) x.im) y.im)
         (if (<= y.re 5.5e+59) t_0 t_1))))))
double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	double t_0 = fma(y_46_im, x_46_im, (y_46_re * x_46_re)) / ((y_46_re * y_46_re) + (y_46_im * y_46_im));
	double t_1 = fma(x_46_im, (y_46_im / y_46_re), x_46_re) / y_46_re;
	double tmp;
	if (y_46_re <= -6.1e+122) {
		tmp = t_1;
	} else if (y_46_re <= -2.8e-116) {
		tmp = t_0;
	} else if (y_46_re <= 8.2e-157) {
		tmp = fma(x_46_re, (y_46_re / y_46_im), x_46_im) / y_46_im;
	} else if (y_46_re <= 5.5e+59) {
		tmp = t_0;
	} else {
		tmp = t_1;
	}
	return tmp;
}
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	t_0 = Float64(fma(y_46_im, x_46_im, Float64(y_46_re * x_46_re)) / Float64(Float64(y_46_re * y_46_re) + Float64(y_46_im * y_46_im)))
	t_1 = Float64(fma(x_46_im, Float64(y_46_im / y_46_re), x_46_re) / y_46_re)
	tmp = 0.0
	if (y_46_re <= -6.1e+122)
		tmp = t_1;
	elseif (y_46_re <= -2.8e-116)
		tmp = t_0;
	elseif (y_46_re <= 8.2e-157)
		tmp = Float64(fma(x_46_re, Float64(y_46_re / y_46_im), x_46_im) / y_46_im);
	elseif (y_46_re <= 5.5e+59)
		tmp = t_0;
	else
		tmp = t_1;
	end
	return tmp
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := Block[{t$95$0 = N[(N[(y$46$im * x$46$im + N[(y$46$re * x$46$re), $MachinePrecision]), $MachinePrecision] / N[(N[(y$46$re * y$46$re), $MachinePrecision] + N[(y$46$im * y$46$im), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(x$46$im * N[(y$46$im / y$46$re), $MachinePrecision] + x$46$re), $MachinePrecision] / y$46$re), $MachinePrecision]}, If[LessEqual[y$46$re, -6.1e+122], t$95$1, If[LessEqual[y$46$re, -2.8e-116], t$95$0, If[LessEqual[y$46$re, 8.2e-157], N[(N[(x$46$re * N[(y$46$re / y$46$im), $MachinePrecision] + x$46$im), $MachinePrecision] / y$46$im), $MachinePrecision], If[LessEqual[y$46$re, 5.5e+59], t$95$0, t$95$1]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{y.re \cdot y.re + y.im \cdot y.im}\\
t_1 := \frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}\\
\mathbf{if}\;y.re \leq -6.1 \cdot 10^{+122}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;y.re \leq -2.8 \cdot 10^{-116}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y.re \leq 8.2 \cdot 10^{-157}:\\
\;\;\;\;\frac{\mathsf{fma}\left(x.re, \frac{y.re}{y.im}, x.im\right)}{y.im}\\

\mathbf{elif}\;y.re \leq 5.5 \cdot 10^{+59}:\\
\;\;\;\;t\_0\\

\mathbf{else}:\\
\;\;\;\;t\_1\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y.re < -6.0999999999999998e122 or 5.4999999999999999e59 < y.re

    1. Initial program 48.7%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \color{blue}{\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}} \]
      2. +-commutativeN/A

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

        \[\leadsto \frac{\color{blue}{x.im \cdot \frac{y.im}{y.re}} + x.re}{y.re} \]
      4. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}}{y.re} \]
      5. /-lowering-/.f6486.8

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \color{blue}{\frac{y.im}{y.re}}, x.re\right)}{y.re} \]
    5. Simplified86.8%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}} \]

    if -6.0999999999999998e122 < y.re < -2.7999999999999999e-116 or 8.2000000000000004e-157 < y.re < 5.4999999999999999e59

    1. Initial program 84.7%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Step-by-step derivation
      1. +-commutativeN/A

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

        \[\leadsto \frac{\color{blue}{y.im \cdot x.im} + x.re \cdot y.re}{y.re \cdot y.re + y.im \cdot y.im} \]
      3. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(y.im, x.im, x.re \cdot y.re\right)}}{y.re \cdot y.re + y.im \cdot y.im} \]
      4. *-lowering-*.f6484.7

        \[\leadsto \frac{\mathsf{fma}\left(y.im, x.im, \color{blue}{x.re \cdot y.re}\right)}{y.re \cdot y.re + y.im \cdot y.im} \]
    4. Applied egg-rr84.7%

      \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(y.im, x.im, x.re \cdot y.re\right)}}{y.re \cdot y.re + y.im \cdot y.im} \]

    if -2.7999999999999999e-116 < y.re < 8.2000000000000004e-157

    1. Initial program 72.4%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Taylor expanded in y.im around inf

      \[\leadsto \color{blue}{\frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \color{blue}{\frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im}} \]
      2. +-commutativeN/A

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

        \[\leadsto \frac{\color{blue}{x.re \cdot \frac{y.re}{y.im}} + x.im}{y.im} \]
      4. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x.re, \frac{y.re}{y.im}, x.im\right)}}{y.im} \]
      5. /-lowering-/.f6494.1

        \[\leadsto \frac{\mathsf{fma}\left(x.re, \color{blue}{\frac{y.re}{y.im}}, x.im\right)}{y.im} \]
    5. Simplified94.1%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x.re, \frac{y.re}{y.im}, x.im\right)}{y.im}} \]
  3. Recombined 3 regimes into one program.
  4. Final simplification88.0%

    \[\leadsto \begin{array}{l} \mathbf{if}\;y.re \leq -6.1 \cdot 10^{+122}:\\ \;\;\;\;\frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}\\ \mathbf{elif}\;y.re \leq -2.8 \cdot 10^{-116}:\\ \;\;\;\;\frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{y.re \cdot y.re + y.im \cdot y.im}\\ \mathbf{elif}\;y.re \leq 8.2 \cdot 10^{-157}:\\ \;\;\;\;\frac{\mathsf{fma}\left(x.re, \frac{y.re}{y.im}, x.im\right)}{y.im}\\ \mathbf{elif}\;y.re \leq 5.5 \cdot 10^{+59}:\\ \;\;\;\;\frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{y.re \cdot y.re + y.im \cdot y.im}\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}\\ \end{array} \]
  5. Add Preprocessing

Alternative 3: 73.2% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}\\ \mathbf{if}\;y.im \leq -5 \cdot 10^{+91}:\\ \;\;\;\;\frac{x.im}{y.im}\\ \mathbf{elif}\;y.im \leq -2.8 \cdot 10^{+76}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y.im \leq -1.5 \cdot 10^{-58}:\\ \;\;\;\;\frac{x.im \cdot y.im}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}\\ \mathbf{elif}\;y.im \leq 2.3 \cdot 10^{+66}:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;\frac{x.im}{y.im}\\ \end{array} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (let* ((t_0 (/ (fma x.im (/ y.im y.re) x.re) y.re)))
   (if (<= y.im -5e+91)
     (/ x.im y.im)
     (if (<= y.im -2.8e+76)
       t_0
       (if (<= y.im -1.5e-58)
         (/ (* x.im y.im) (fma y.im y.im (* y.re y.re)))
         (if (<= y.im 2.3e+66) t_0 (/ x.im y.im)))))))
double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	double t_0 = fma(x_46_im, (y_46_im / y_46_re), x_46_re) / y_46_re;
	double tmp;
	if (y_46_im <= -5e+91) {
		tmp = x_46_im / y_46_im;
	} else if (y_46_im <= -2.8e+76) {
		tmp = t_0;
	} else if (y_46_im <= -1.5e-58) {
		tmp = (x_46_im * y_46_im) / fma(y_46_im, y_46_im, (y_46_re * y_46_re));
	} else if (y_46_im <= 2.3e+66) {
		tmp = t_0;
	} else {
		tmp = x_46_im / y_46_im;
	}
	return tmp;
}
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	t_0 = Float64(fma(x_46_im, Float64(y_46_im / y_46_re), x_46_re) / y_46_re)
	tmp = 0.0
	if (y_46_im <= -5e+91)
		tmp = Float64(x_46_im / y_46_im);
	elseif (y_46_im <= -2.8e+76)
		tmp = t_0;
	elseif (y_46_im <= -1.5e-58)
		tmp = Float64(Float64(x_46_im * y_46_im) / fma(y_46_im, y_46_im, Float64(y_46_re * y_46_re)));
	elseif (y_46_im <= 2.3e+66)
		tmp = t_0;
	else
		tmp = Float64(x_46_im / y_46_im);
	end
	return tmp
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := Block[{t$95$0 = N[(N[(x$46$im * N[(y$46$im / y$46$re), $MachinePrecision] + x$46$re), $MachinePrecision] / y$46$re), $MachinePrecision]}, If[LessEqual[y$46$im, -5e+91], N[(x$46$im / y$46$im), $MachinePrecision], If[LessEqual[y$46$im, -2.8e+76], t$95$0, If[LessEqual[y$46$im, -1.5e-58], N[(N[(x$46$im * y$46$im), $MachinePrecision] / N[(y$46$im * y$46$im + N[(y$46$re * y$46$re), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[y$46$im, 2.3e+66], t$95$0, N[(x$46$im / y$46$im), $MachinePrecision]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}\\
\mathbf{if}\;y.im \leq -5 \cdot 10^{+91}:\\
\;\;\;\;\frac{x.im}{y.im}\\

\mathbf{elif}\;y.im \leq -2.8 \cdot 10^{+76}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y.im \leq -1.5 \cdot 10^{-58}:\\
\;\;\;\;\frac{x.im \cdot y.im}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}\\

\mathbf{elif}\;y.im \leq 2.3 \cdot 10^{+66}:\\
\;\;\;\;t\_0\\

\mathbf{else}:\\
\;\;\;\;\frac{x.im}{y.im}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y.im < -5.0000000000000002e91 or 2.3e66 < y.im

    1. Initial program 53.1%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Taylor expanded in y.re around 0

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f6475.2

        \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    5. Simplified75.2%

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]

    if -5.0000000000000002e91 < y.im < -2.7999999999999999e76 or -1.50000000000000004e-58 < y.im < 2.3e66

    1. Initial program 72.6%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \color{blue}{\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}} \]
      2. +-commutativeN/A

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

        \[\leadsto \frac{\color{blue}{x.im \cdot \frac{y.im}{y.re}} + x.re}{y.re} \]
      4. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}}{y.re} \]
      5. /-lowering-/.f6486.3

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \color{blue}{\frac{y.im}{y.re}}, x.re\right)}{y.re} \]
    5. Simplified86.3%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}} \]

    if -2.7999999999999999e76 < y.im < -1.50000000000000004e-58

    1. Initial program 89.4%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Taylor expanded in x.re around 0

      \[\leadsto \color{blue}{\frac{x.im \cdot y.im}{{y.im}^{2} + {y.re}^{2}}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \color{blue}{\frac{x.im \cdot y.im}{{y.im}^{2} + {y.re}^{2}}} \]
      2. *-lowering-*.f64N/A

        \[\leadsto \frac{\color{blue}{x.im \cdot y.im}}{{y.im}^{2} + {y.re}^{2}} \]
      3. unpow2N/A

        \[\leadsto \frac{x.im \cdot y.im}{\color{blue}{y.im \cdot y.im} + {y.re}^{2}} \]
      4. accelerator-lowering-fma.f64N/A

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

        \[\leadsto \frac{x.im \cdot y.im}{\mathsf{fma}\left(y.im, y.im, \color{blue}{y.re \cdot y.re}\right)} \]
      6. *-lowering-*.f6476.5

        \[\leadsto \frac{x.im \cdot y.im}{\mathsf{fma}\left(y.im, y.im, \color{blue}{y.re \cdot y.re}\right)} \]
    5. Simplified76.5%

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

Alternative 4: 78.4% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y.re \leq -0.75:\\ \;\;\;\;\mathsf{fma}\left(y.im, \frac{x.im}{y.re}, x.re\right) \cdot \frac{1}{y.re}\\ \mathbf{elif}\;y.re \leq 2.6 \cdot 10^{-30}:\\ \;\;\;\;\frac{\mathsf{fma}\left(x.re, \frac{y.re}{y.im}, x.im\right)}{y.im}\\ \mathbf{else}:\\ \;\;\;\;\frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}\\ \end{array} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (if (<= y.re -0.75)
   (* (fma y.im (/ x.im y.re) x.re) (/ 1.0 y.re))
   (if (<= y.re 2.6e-30)
     (/ (fma x.re (/ y.re y.im) x.im) y.im)
     (/ (fma x.im (/ y.im y.re) x.re) y.re))))
double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	double tmp;
	if (y_46_re <= -0.75) {
		tmp = fma(y_46_im, (x_46_im / y_46_re), x_46_re) * (1.0 / y_46_re);
	} else if (y_46_re <= 2.6e-30) {
		tmp = fma(x_46_re, (y_46_re / y_46_im), x_46_im) / y_46_im;
	} else {
		tmp = fma(x_46_im, (y_46_im / y_46_re), x_46_re) / y_46_re;
	}
	return tmp;
}
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	tmp = 0.0
	if (y_46_re <= -0.75)
		tmp = Float64(fma(y_46_im, Float64(x_46_im / y_46_re), x_46_re) * Float64(1.0 / y_46_re));
	elseif (y_46_re <= 2.6e-30)
		tmp = Float64(fma(x_46_re, Float64(y_46_re / y_46_im), x_46_im) / y_46_im);
	else
		tmp = Float64(fma(x_46_im, Float64(y_46_im / y_46_re), x_46_re) / y_46_re);
	end
	return tmp
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := If[LessEqual[y$46$re, -0.75], N[(N[(y$46$im * N[(x$46$im / y$46$re), $MachinePrecision] + x$46$re), $MachinePrecision] * N[(1.0 / y$46$re), $MachinePrecision]), $MachinePrecision], If[LessEqual[y$46$re, 2.6e-30], N[(N[(x$46$re * N[(y$46$re / y$46$im), $MachinePrecision] + x$46$im), $MachinePrecision] / y$46$im), $MachinePrecision], N[(N[(x$46$im * N[(y$46$im / y$46$re), $MachinePrecision] + x$46$re), $MachinePrecision] / y$46$re), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y.re \leq -0.75:\\
\;\;\;\;\mathsf{fma}\left(y.im, \frac{x.im}{y.re}, x.re\right) \cdot \frac{1}{y.re}\\

\mathbf{elif}\;y.re \leq 2.6 \cdot 10^{-30}:\\
\;\;\;\;\frac{\mathsf{fma}\left(x.re, \frac{y.re}{y.im}, x.im\right)}{y.im}\\

\mathbf{else}:\\
\;\;\;\;\frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}\\


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y.re < -0.75

    1. Initial program 57.0%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \color{blue}{\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}} \]
      2. +-commutativeN/A

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

        \[\leadsto \frac{\color{blue}{x.im \cdot \frac{y.im}{y.re}} + x.re}{y.re} \]
      4. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}}{y.re} \]
      5. /-lowering-/.f6480.8

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \color{blue}{\frac{y.im}{y.re}}, x.re\right)}{y.re} \]
    5. Simplified80.8%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}} \]
    6. Step-by-step derivation
      1. div-invN/A

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

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

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

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

        \[\leadsto \left(\color{blue}{y.im \cdot \frac{x.im}{y.re}} + x.re\right) \cdot \frac{1}{y.re} \]
      6. accelerator-lowering-fma.f64N/A

        \[\leadsto \color{blue}{\mathsf{fma}\left(y.im, \frac{x.im}{y.re}, x.re\right)} \cdot \frac{1}{y.re} \]
      7. /-lowering-/.f64N/A

        \[\leadsto \mathsf{fma}\left(y.im, \color{blue}{\frac{x.im}{y.re}}, x.re\right) \cdot \frac{1}{y.re} \]
      8. /-lowering-/.f6481.9

        \[\leadsto \mathsf{fma}\left(y.im, \frac{x.im}{y.re}, x.re\right) \cdot \color{blue}{\frac{1}{y.re}} \]
    7. Applied egg-rr81.9%

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

    if -0.75 < y.re < 2.59999999999999987e-30

    1. Initial program 77.3%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Taylor expanded in y.im around inf

      \[\leadsto \color{blue}{\frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \color{blue}{\frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im}} \]
      2. +-commutativeN/A

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

        \[\leadsto \frac{\color{blue}{x.re \cdot \frac{y.re}{y.im}} + x.im}{y.im} \]
      4. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x.re, \frac{y.re}{y.im}, x.im\right)}}{y.im} \]
      5. /-lowering-/.f6484.3

        \[\leadsto \frac{\mathsf{fma}\left(x.re, \color{blue}{\frac{y.re}{y.im}}, x.im\right)}{y.im} \]
    5. Simplified84.3%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x.re, \frac{y.re}{y.im}, x.im\right)}{y.im}} \]

    if 2.59999999999999987e-30 < y.re

    1. Initial program 61.9%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \color{blue}{\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}} \]
      2. +-commutativeN/A

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

        \[\leadsto \frac{\color{blue}{x.im \cdot \frac{y.im}{y.re}} + x.re}{y.re} \]
      4. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}}{y.re} \]
      5. /-lowering-/.f6480.0

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \color{blue}{\frac{y.im}{y.re}}, x.re\right)}{y.re} \]
    5. Simplified80.0%

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

Alternative 5: 78.2% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}\\ \mathbf{if}\;y.re \leq -0.85:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y.re \leq 2.3 \cdot 10^{-30}:\\ \;\;\;\;\frac{\mathsf{fma}\left(x.re, \frac{y.re}{y.im}, x.im\right)}{y.im}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (let* ((t_0 (/ (fma x.im (/ y.im y.re) x.re) y.re)))
   (if (<= y.re -0.85)
     t_0
     (if (<= y.re 2.3e-30) (/ (fma x.re (/ y.re y.im) x.im) y.im) t_0))))
double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	double t_0 = fma(x_46_im, (y_46_im / y_46_re), x_46_re) / y_46_re;
	double tmp;
	if (y_46_re <= -0.85) {
		tmp = t_0;
	} else if (y_46_re <= 2.3e-30) {
		tmp = fma(x_46_re, (y_46_re / y_46_im), x_46_im) / y_46_im;
	} else {
		tmp = t_0;
	}
	return tmp;
}
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	t_0 = Float64(fma(x_46_im, Float64(y_46_im / y_46_re), x_46_re) / y_46_re)
	tmp = 0.0
	if (y_46_re <= -0.85)
		tmp = t_0;
	elseif (y_46_re <= 2.3e-30)
		tmp = Float64(fma(x_46_re, Float64(y_46_re / y_46_im), x_46_im) / y_46_im);
	else
		tmp = t_0;
	end
	return tmp
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := Block[{t$95$0 = N[(N[(x$46$im * N[(y$46$im / y$46$re), $MachinePrecision] + x$46$re), $MachinePrecision] / y$46$re), $MachinePrecision]}, If[LessEqual[y$46$re, -0.85], t$95$0, If[LessEqual[y$46$re, 2.3e-30], N[(N[(x$46$re * N[(y$46$re / y$46$im), $MachinePrecision] + x$46$im), $MachinePrecision] / y$46$im), $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}\\
\mathbf{if}\;y.re \leq -0.85:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y.re \leq 2.3 \cdot 10^{-30}:\\
\;\;\;\;\frac{\mathsf{fma}\left(x.re, \frac{y.re}{y.im}, x.im\right)}{y.im}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y.re < -0.849999999999999978 or 2.29999999999999984e-30 < y.re

    1. Initial program 59.5%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \color{blue}{\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}} \]
      2. +-commutativeN/A

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

        \[\leadsto \frac{\color{blue}{x.im \cdot \frac{y.im}{y.re}} + x.re}{y.re} \]
      4. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}}{y.re} \]
      5. /-lowering-/.f6480.4

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \color{blue}{\frac{y.im}{y.re}}, x.re\right)}{y.re} \]
    5. Simplified80.4%

      \[\leadsto \color{blue}{\frac{\mathsf{fma}\left(x.im, \frac{y.im}{y.re}, x.re\right)}{y.re}} \]

    if -0.849999999999999978 < y.re < 2.29999999999999984e-30

    1. Initial program 77.3%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Taylor expanded in y.im around inf

      \[\leadsto \color{blue}{\frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f64N/A

        \[\leadsto \color{blue}{\frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im}} \]
      2. +-commutativeN/A

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

        \[\leadsto \frac{\color{blue}{x.re \cdot \frac{y.re}{y.im}} + x.im}{y.im} \]
      4. accelerator-lowering-fma.f64N/A

        \[\leadsto \frac{\color{blue}{\mathsf{fma}\left(x.re, \frac{y.re}{y.im}, x.im\right)}}{y.im} \]
      5. /-lowering-/.f6484.3

        \[\leadsto \frac{\mathsf{fma}\left(x.re, \color{blue}{\frac{y.re}{y.im}}, x.im\right)}{y.im} \]
    5. Simplified84.3%

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

Alternative 6: 64.4% accurate, 1.6× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y.re \leq -0.58:\\ \;\;\;\;\frac{x.re}{y.re}\\ \mathbf{elif}\;y.re \leq 3 \cdot 10^{+22}:\\ \;\;\;\;\frac{x.im}{y.im}\\ \mathbf{else}:\\ \;\;\;\;\frac{x.re}{y.re}\\ \end{array} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (if (<= y.re -0.58)
   (/ x.re y.re)
   (if (<= y.re 3e+22) (/ x.im y.im) (/ x.re y.re))))
double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	double tmp;
	if (y_46_re <= -0.58) {
		tmp = x_46_re / y_46_re;
	} else if (y_46_re <= 3e+22) {
		tmp = x_46_im / y_46_im;
	} else {
		tmp = x_46_re / y_46_re;
	}
	return tmp;
}
real(8) function code(x_46re, x_46im, y_46re, y_46im)
    real(8), intent (in) :: x_46re
    real(8), intent (in) :: x_46im
    real(8), intent (in) :: y_46re
    real(8), intent (in) :: y_46im
    real(8) :: tmp
    if (y_46re <= (-0.58d0)) then
        tmp = x_46re / y_46re
    else if (y_46re <= 3d+22) then
        tmp = x_46im / y_46im
    else
        tmp = x_46re / y_46re
    end if
    code = tmp
end function
public static double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	double tmp;
	if (y_46_re <= -0.58) {
		tmp = x_46_re / y_46_re;
	} else if (y_46_re <= 3e+22) {
		tmp = x_46_im / y_46_im;
	} else {
		tmp = x_46_re / y_46_re;
	}
	return tmp;
}
def code(x_46_re, x_46_im, y_46_re, y_46_im):
	tmp = 0
	if y_46_re <= -0.58:
		tmp = x_46_re / y_46_re
	elif y_46_re <= 3e+22:
		tmp = x_46_im / y_46_im
	else:
		tmp = x_46_re / y_46_re
	return tmp
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	tmp = 0.0
	if (y_46_re <= -0.58)
		tmp = Float64(x_46_re / y_46_re);
	elseif (y_46_re <= 3e+22)
		tmp = Float64(x_46_im / y_46_im);
	else
		tmp = Float64(x_46_re / y_46_re);
	end
	return tmp
end
function tmp_2 = code(x_46_re, x_46_im, y_46_re, y_46_im)
	tmp = 0.0;
	if (y_46_re <= -0.58)
		tmp = x_46_re / y_46_re;
	elseif (y_46_re <= 3e+22)
		tmp = x_46_im / y_46_im;
	else
		tmp = x_46_re / y_46_re;
	end
	tmp_2 = tmp;
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := If[LessEqual[y$46$re, -0.58], N[(x$46$re / y$46$re), $MachinePrecision], If[LessEqual[y$46$re, 3e+22], N[(x$46$im / y$46$im), $MachinePrecision], N[(x$46$re / y$46$re), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y.re \leq -0.58:\\
\;\;\;\;\frac{x.re}{y.re}\\

\mathbf{elif}\;y.re \leq 3 \cdot 10^{+22}:\\
\;\;\;\;\frac{x.im}{y.im}\\

\mathbf{else}:\\
\;\;\;\;\frac{x.re}{y.re}\\


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y.re < -0.57999999999999996 or 3e22 < y.re

    1. Initial program 58.9%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f6473.7

        \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    5. Simplified73.7%

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]

    if -0.57999999999999996 < y.re < 3e22

    1. Initial program 76.9%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Add Preprocessing
    3. Taylor expanded in y.re around 0

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    4. Step-by-step derivation
      1. /-lowering-/.f6470.4

        \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    5. Simplified70.4%

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

Alternative 7: 42.9% accurate, 3.2× speedup?

\[\begin{array}{l} \\ \frac{x.im}{y.im} \end{array} \]
(FPCore (x.re x.im y.re y.im) :precision binary64 (/ x.im y.im))
double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	return x_46_im / y_46_im;
}
real(8) function code(x_46re, x_46im, y_46re, y_46im)
    real(8), intent (in) :: x_46re
    real(8), intent (in) :: x_46im
    real(8), intent (in) :: y_46re
    real(8), intent (in) :: y_46im
    code = x_46im / y_46im
end function
public static double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	return x_46_im / y_46_im;
}
def code(x_46_re, x_46_im, y_46_re, y_46_im):
	return x_46_im / y_46_im
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	return Float64(x_46_im / y_46_im)
end
function tmp = code(x_46_re, x_46_im, y_46_re, y_46_im)
	tmp = x_46_im / y_46_im;
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := N[(x$46$im / y$46$im), $MachinePrecision]
\begin{array}{l}

\\
\frac{x.im}{y.im}
\end{array}
Derivation
  1. Initial program 67.6%

    \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
  2. Add Preprocessing
  3. Taylor expanded in y.re around 0

    \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
  4. Step-by-step derivation
    1. /-lowering-/.f6443.8

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
  5. Simplified43.8%

    \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
  6. Add Preprocessing

Reproduce

?
herbie shell --seed 2024199 
(FPCore (x.re x.im y.re y.im)
  :name "_divideComplex, real part"
  :precision binary64
  (/ (+ (* x.re y.re) (* x.im y.im)) (+ (* y.re y.re) (* y.im y.im))))