_divideComplex, real part

Percentage Accurate: 61.8% → 84.2%
Time: 2.7s
Alternatives: 9
Speedup: 1.8×

Specification

?
\[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
(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)
use fmin_fmax_functions
    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]
\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im}

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 9 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: 61.8% accurate, 1.0× speedup?

\[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
(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)
use fmin_fmax_functions
    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]
\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im}

Alternative 1: 84.2% accurate, 0.4× speedup?

\[\begin{array}{l} t_0 := \mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)\\ t_1 := \mathsf{fma}\left(x.im, \frac{y.im}{t\_0}, y.re \cdot \frac{x.re}{t\_0}\right)\\ t_2 := \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im}\\ t_3 := \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}\\ \mathbf{if}\;y.im \leq -9.8 \cdot 10^{+169}:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;y.im \leq -3.6 \cdot 10^{+30}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;y.im \leq -5 \cdot 10^{-22}:\\ \;\;\;\;t\_3\\ \mathbf{elif}\;y.im \leq -2.9 \cdot 10^{-97}:\\ \;\;\;\;\frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{t\_0}\\ \mathbf{elif}\;y.im \leq 1.1 \cdot 10^{-40}:\\ \;\;\;\;t\_3\\ \mathbf{elif}\;y.im \leq 1.15 \cdot 10^{+136}:\\ \;\;\;\;t\_1\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \]
(FPCore (x.re x.im y.re y.im)
  :precision binary64
  (let* ((t_0 (fma y.im y.im (* y.re y.re)))
       (t_1 (fma x.im (/ y.im t_0) (* y.re (/ x.re t_0))))
       (t_2 (/ (fma y.re (/ x.re y.im) x.im) y.im))
       (t_3 (/ (+ x.re (/ (* x.im y.im) y.re)) y.re)))
  (if (<= y.im -9.8e+169)
    t_2
    (if (<= y.im -3.6e+30)
      t_1
      (if (<= y.im -5e-22)
        t_3
        (if (<= y.im -2.9e-97)
          (/ (fma y.im x.im (* y.re x.re)) t_0)
          (if (<= y.im 1.1e-40)
            t_3
            (if (<= y.im 1.15e+136) t_1 t_2))))))))
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, y_46_im, (y_46_re * y_46_re));
	double t_1 = fma(x_46_im, (y_46_im / t_0), (y_46_re * (x_46_re / t_0)));
	double t_2 = fma(y_46_re, (x_46_re / y_46_im), x_46_im) / y_46_im;
	double t_3 = (x_46_re + ((x_46_im * y_46_im) / y_46_re)) / y_46_re;
	double tmp;
	if (y_46_im <= -9.8e+169) {
		tmp = t_2;
	} else if (y_46_im <= -3.6e+30) {
		tmp = t_1;
	} else if (y_46_im <= -5e-22) {
		tmp = t_3;
	} else if (y_46_im <= -2.9e-97) {
		tmp = fma(y_46_im, x_46_im, (y_46_re * x_46_re)) / t_0;
	} else if (y_46_im <= 1.1e-40) {
		tmp = t_3;
	} else if (y_46_im <= 1.15e+136) {
		tmp = t_1;
	} else {
		tmp = t_2;
	}
	return tmp;
}
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	t_0 = fma(y_46_im, y_46_im, Float64(y_46_re * y_46_re))
	t_1 = fma(x_46_im, Float64(y_46_im / t_0), Float64(y_46_re * Float64(x_46_re / t_0)))
	t_2 = Float64(fma(y_46_re, Float64(x_46_re / y_46_im), x_46_im) / y_46_im)
	t_3 = Float64(Float64(x_46_re + Float64(Float64(x_46_im * y_46_im) / y_46_re)) / y_46_re)
	tmp = 0.0
	if (y_46_im <= -9.8e+169)
		tmp = t_2;
	elseif (y_46_im <= -3.6e+30)
		tmp = t_1;
	elseif (y_46_im <= -5e-22)
		tmp = t_3;
	elseif (y_46_im <= -2.9e-97)
		tmp = Float64(fma(y_46_im, x_46_im, Float64(y_46_re * x_46_re)) / t_0);
	elseif (y_46_im <= 1.1e-40)
		tmp = t_3;
	elseif (y_46_im <= 1.15e+136)
		tmp = t_1;
	else
		tmp = t_2;
	end
	return tmp
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := Block[{t$95$0 = N[(y$46$im * y$46$im + N[(y$46$re * y$46$re), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(x$46$im * N[(y$46$im / t$95$0), $MachinePrecision] + N[(y$46$re * N[(x$46$re / t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(y$46$re * N[(x$46$re / y$46$im), $MachinePrecision] + x$46$im), $MachinePrecision] / y$46$im), $MachinePrecision]}, Block[{t$95$3 = N[(N[(x$46$re + N[(N[(x$46$im * y$46$im), $MachinePrecision] / y$46$re), $MachinePrecision]), $MachinePrecision] / y$46$re), $MachinePrecision]}, If[LessEqual[y$46$im, -9.8e+169], t$95$2, If[LessEqual[y$46$im, -3.6e+30], t$95$1, If[LessEqual[y$46$im, -5e-22], t$95$3, If[LessEqual[y$46$im, -2.9e-97], N[(N[(y$46$im * x$46$im + N[(y$46$re * x$46$re), $MachinePrecision]), $MachinePrecision] / t$95$0), $MachinePrecision], If[LessEqual[y$46$im, 1.1e-40], t$95$3, If[LessEqual[y$46$im, 1.15e+136], t$95$1, t$95$2]]]]]]]]]]
\begin{array}{l}
t_0 := \mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)\\
t_1 := \mathsf{fma}\left(x.im, \frac{y.im}{t\_0}, y.re \cdot \frac{x.re}{t\_0}\right)\\
t_2 := \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im}\\
t_3 := \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}\\
\mathbf{if}\;y.im \leq -9.8 \cdot 10^{+169}:\\
\;\;\;\;t\_2\\

\mathbf{elif}\;y.im \leq -3.6 \cdot 10^{+30}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;y.im \leq -5 \cdot 10^{-22}:\\
\;\;\;\;t\_3\\

\mathbf{elif}\;y.im \leq -2.9 \cdot 10^{-97}:\\
\;\;\;\;\frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{t\_0}\\

\mathbf{elif}\;y.im \leq 1.1 \cdot 10^{-40}:\\
\;\;\;\;t\_3\\

\mathbf{elif}\;y.im \leq 1.15 \cdot 10^{+136}:\\
\;\;\;\;t\_1\\

\mathbf{else}:\\
\;\;\;\;t\_2\\


\end{array}
Derivation
  1. Split input into 4 regimes
  2. if y.im < -9.8000000000000005e169 or 1.15e136 < y.im

    1. Initial program 61.8%

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

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

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

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
      4. lower-*.f6452.8%

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
    4. Applied rewrites52.8%

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

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

        \[\leadsto \frac{\frac{x.re \cdot y.re}{y.im} + x.im}{y.im} \]
      3. lift-/.f64N/A

        \[\leadsto \frac{\frac{x.re \cdot y.re}{y.im} + x.im}{y.im} \]
      4. lift-*.f64N/A

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

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

        \[\leadsto \frac{y.re \cdot \frac{x.re}{y.im} + x.im}{y.im} \]
      7. lower-fma.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
      8. lower-/.f6454.1%

        \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
    6. Applied rewrites54.1%

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

    if -9.8000000000000005e169 < y.im < -3.6000000000000002e30 or 1.1e-40 < y.im < 1.15e136

    1. Initial program 61.8%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

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

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

        \[\leadsto \frac{\color{blue}{x.im \cdot y.im + x.re \cdot y.re}}{y.re \cdot y.re + y.im \cdot y.im} \]
      4. div-addN/A

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

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(x.im, \frac{y.im}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, \color{blue}{y.re \cdot \frac{x.re}{y.re \cdot y.re + y.im \cdot y.im}}\right) \]
      17. lower-/.f6461.9%

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

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

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

        \[\leadsto \mathsf{fma}\left(x.im, \frac{y.im}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, y.re \cdot \frac{x.re}{\color{blue}{y.im \cdot y.im} + y.re \cdot y.re}\right) \]
      21. lower-fma.f6461.9%

        \[\leadsto \mathsf{fma}\left(x.im, \frac{y.im}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, y.re \cdot \frac{x.re}{\color{blue}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}}\right) \]
    3. Applied rewrites61.9%

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

    if -3.6000000000000002e30 < y.im < -4.9999999999999995e-22 or -2.8999999999999999e-97 < y.im < 1.1e-40

    1. Initial program 61.8%

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

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    3. Step-by-step derivation
      1. lower-/.f6443.2%

        \[\leadsto \frac{x.im}{\color{blue}{y.im}} \]
    4. Applied rewrites43.2%

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    5. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    6. Step-by-step derivation
      1. lower-/.f6442.0%

        \[\leadsto \frac{x.re}{\color{blue}{y.re}} \]
    7. Applied rewrites42.0%

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    8. Taylor expanded in y.re around inf

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

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

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
      4. lower-*.f6451.1%

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
    10. Applied rewrites51.1%

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

    if -4.9999999999999995e-22 < y.im < -2.8999999999999999e-97

    1. Initial program 61.8%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Step-by-step derivation
      1. lift-+.f64N/A

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

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

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

        \[\leadsto \frac{\color{blue}{y.im \cdot x.im} + x.re \cdot y.re}{y.re \cdot y.re + y.im \cdot y.im} \]
      5. lower-fma.f6461.8%

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

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

        \[\leadsto \frac{\mathsf{fma}\left(y.im, x.im, \color{blue}{y.re \cdot x.re}\right)}{y.re \cdot y.re + y.im \cdot y.im} \]
      8. lower-*.f6461.8%

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

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

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

        \[\leadsto \frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{\color{blue}{y.im \cdot y.im} + y.re \cdot y.re} \]
      12. lower-fma.f6461.8%

        \[\leadsto \frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{\color{blue}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}} \]
    3. Applied rewrites61.8%

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

Alternative 2: 83.4% accurate, 0.5× speedup?

\[\begin{array}{l} t_0 := \mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)\\ t_1 := \frac{y.re}{t\_0}\\ t_2 := \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im}\\ \mathbf{if}\;y.im \leq -9.8 \cdot 10^{+169}:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;y.im \leq -2.9 \cdot 10^{-97}:\\ \;\;\;\;\mathsf{fma}\left(x.re, t\_1, x.im \cdot \frac{y.im}{t\_0}\right)\\ \mathbf{elif}\;y.im \leq 2.5 \cdot 10^{-99}:\\ \;\;\;\;\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}\\ \mathbf{elif}\;y.im \leq 1.85 \cdot 10^{+123}:\\ \;\;\;\;\mathsf{fma}\left(x.re, t\_1, y.im \cdot \frac{x.im}{t\_0}\right)\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \]
(FPCore (x.re x.im y.re y.im)
  :precision binary64
  (let* ((t_0 (fma y.im y.im (* y.re y.re)))
       (t_1 (/ y.re t_0))
       (t_2 (/ (fma y.re (/ x.re y.im) x.im) y.im)))
  (if (<= y.im -9.8e+169)
    t_2
    (if (<= y.im -2.9e-97)
      (fma x.re t_1 (* x.im (/ y.im t_0)))
      (if (<= y.im 2.5e-99)
        (/ (+ x.re (/ (* x.im y.im) y.re)) y.re)
        (if (<= y.im 1.85e+123)
          (fma x.re t_1 (* y.im (/ x.im t_0)))
          t_2))))))
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, y_46_im, (y_46_re * y_46_re));
	double t_1 = y_46_re / t_0;
	double t_2 = fma(y_46_re, (x_46_re / y_46_im), x_46_im) / y_46_im;
	double tmp;
	if (y_46_im <= -9.8e+169) {
		tmp = t_2;
	} else if (y_46_im <= -2.9e-97) {
		tmp = fma(x_46_re, t_1, (x_46_im * (y_46_im / t_0)));
	} else if (y_46_im <= 2.5e-99) {
		tmp = (x_46_re + ((x_46_im * y_46_im) / y_46_re)) / y_46_re;
	} else if (y_46_im <= 1.85e+123) {
		tmp = fma(x_46_re, t_1, (y_46_im * (x_46_im / t_0)));
	} else {
		tmp = t_2;
	}
	return tmp;
}
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	t_0 = fma(y_46_im, y_46_im, Float64(y_46_re * y_46_re))
	t_1 = Float64(y_46_re / t_0)
	t_2 = Float64(fma(y_46_re, Float64(x_46_re / y_46_im), x_46_im) / y_46_im)
	tmp = 0.0
	if (y_46_im <= -9.8e+169)
		tmp = t_2;
	elseif (y_46_im <= -2.9e-97)
		tmp = fma(x_46_re, t_1, Float64(x_46_im * Float64(y_46_im / t_0)));
	elseif (y_46_im <= 2.5e-99)
		tmp = Float64(Float64(x_46_re + Float64(Float64(x_46_im * y_46_im) / y_46_re)) / y_46_re);
	elseif (y_46_im <= 1.85e+123)
		tmp = fma(x_46_re, t_1, Float64(y_46_im * Float64(x_46_im / t_0)));
	else
		tmp = t_2;
	end
	return tmp
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := Block[{t$95$0 = N[(y$46$im * y$46$im + N[(y$46$re * y$46$re), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(y$46$re / t$95$0), $MachinePrecision]}, Block[{t$95$2 = N[(N[(y$46$re * N[(x$46$re / y$46$im), $MachinePrecision] + x$46$im), $MachinePrecision] / y$46$im), $MachinePrecision]}, If[LessEqual[y$46$im, -9.8e+169], t$95$2, If[LessEqual[y$46$im, -2.9e-97], N[(x$46$re * t$95$1 + N[(x$46$im * N[(y$46$im / t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[y$46$im, 2.5e-99], N[(N[(x$46$re + N[(N[(x$46$im * y$46$im), $MachinePrecision] / y$46$re), $MachinePrecision]), $MachinePrecision] / y$46$re), $MachinePrecision], If[LessEqual[y$46$im, 1.85e+123], N[(x$46$re * t$95$1 + N[(y$46$im * N[(x$46$im / t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$2]]]]]]]
\begin{array}{l}
t_0 := \mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)\\
t_1 := \frac{y.re}{t\_0}\\
t_2 := \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im}\\
\mathbf{if}\;y.im \leq -9.8 \cdot 10^{+169}:\\
\;\;\;\;t\_2\\

\mathbf{elif}\;y.im \leq -2.9 \cdot 10^{-97}:\\
\;\;\;\;\mathsf{fma}\left(x.re, t\_1, x.im \cdot \frac{y.im}{t\_0}\right)\\

\mathbf{elif}\;y.im \leq 2.5 \cdot 10^{-99}:\\
\;\;\;\;\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}\\

\mathbf{elif}\;y.im \leq 1.85 \cdot 10^{+123}:\\
\;\;\;\;\mathsf{fma}\left(x.re, t\_1, y.im \cdot \frac{x.im}{t\_0}\right)\\

\mathbf{else}:\\
\;\;\;\;t\_2\\


\end{array}
Derivation
  1. Split input into 4 regimes
  2. if y.im < -9.8000000000000005e169 or 1.85e123 < y.im

    1. Initial program 61.8%

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

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

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

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
      4. lower-*.f6452.8%

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
    4. Applied rewrites52.8%

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

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

        \[\leadsto \frac{\frac{x.re \cdot y.re}{y.im} + x.im}{y.im} \]
      3. lift-/.f64N/A

        \[\leadsto \frac{\frac{x.re \cdot y.re}{y.im} + x.im}{y.im} \]
      4. lift-*.f64N/A

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

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

        \[\leadsto \frac{y.re \cdot \frac{x.re}{y.im} + x.im}{y.im} \]
      7. lower-fma.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
      8. lower-/.f6454.1%

        \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
    6. Applied rewrites54.1%

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

    if -9.8000000000000005e169 < y.im < -2.8999999999999999e-97

    1. Initial program 61.8%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

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

        \[\leadsto \frac{\color{blue}{x.re \cdot y.re + x.im \cdot y.im}}{y.re \cdot y.re + y.im \cdot y.im} \]
      3. div-addN/A

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, \color{blue}{y.im \cdot \frac{x.im}{y.re \cdot y.re + y.im \cdot y.im}}\right) \]
      15. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, \color{blue}{y.im \cdot \frac{x.im}{y.re \cdot y.re + y.im \cdot y.im}}\right) \]
      16. lower-/.f6461.5%

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

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

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

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, y.im \cdot \frac{x.im}{\color{blue}{y.im \cdot y.im} + y.re \cdot y.re}\right) \]
      20. lower-fma.f6461.5%

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, y.im \cdot \frac{x.im}{\color{blue}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}}\right) \]
    3. Applied rewrites61.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, y.im \cdot \frac{x.im}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}\right)} \]
    4. Step-by-step derivation
      1. lift-*.f64N/A

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

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

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, \color{blue}{\frac{x.im}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}} \cdot y.im\right) \]
      4. associate-*l/N/A

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

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

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, \color{blue}{x.im \cdot \frac{y.im}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}}\right) \]
      7. lower-/.f6465.0%

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, x.im \cdot \color{blue}{\frac{y.im}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}}\right) \]
    5. Applied rewrites65.0%

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

    if -2.8999999999999999e-97 < y.im < 2.4999999999999998e-99

    1. Initial program 61.8%

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

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    3. Step-by-step derivation
      1. lower-/.f6443.2%

        \[\leadsto \frac{x.im}{\color{blue}{y.im}} \]
    4. Applied rewrites43.2%

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    5. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    6. Step-by-step derivation
      1. lower-/.f6442.0%

        \[\leadsto \frac{x.re}{\color{blue}{y.re}} \]
    7. Applied rewrites42.0%

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    8. Taylor expanded in y.re around inf

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

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

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
      4. lower-*.f6451.1%

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
    10. Applied rewrites51.1%

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

    if 2.4999999999999998e-99 < y.im < 1.85e123

    1. Initial program 61.8%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

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

        \[\leadsto \frac{\color{blue}{x.re \cdot y.re + x.im \cdot y.im}}{y.re \cdot y.re + y.im \cdot y.im} \]
      3. div-addN/A

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, \color{blue}{y.im \cdot \frac{x.im}{y.re \cdot y.re + y.im \cdot y.im}}\right) \]
      15. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, \color{blue}{y.im \cdot \frac{x.im}{y.re \cdot y.re + y.im \cdot y.im}}\right) \]
      16. lower-/.f6461.5%

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

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

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

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, y.im \cdot \frac{x.im}{\color{blue}{y.im \cdot y.im} + y.re \cdot y.re}\right) \]
      20. lower-fma.f6461.5%

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, y.im \cdot \frac{x.im}{\color{blue}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}}\right) \]
    3. Applied rewrites61.5%

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

Alternative 3: 82.6% accurate, 0.5× speedup?

\[\begin{array}{l} t_0 := \mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)\\ t_1 := \mathsf{fma}\left(x.re, \frac{y.re}{t\_0}, x.im \cdot \frac{y.im}{t\_0}\right)\\ t_2 := \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im}\\ \mathbf{if}\;y.im \leq -9.8 \cdot 10^{+169}:\\ \;\;\;\;t\_2\\ \mathbf{elif}\;y.im \leq -2.9 \cdot 10^{-97}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;y.im \leq 4 \cdot 10^{-131}:\\ \;\;\;\;\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}\\ \mathbf{elif}\;y.im \leq 1.15 \cdot 10^{+136}:\\ \;\;\;\;t\_1\\ \mathbf{else}:\\ \;\;\;\;t\_2\\ \end{array} \]
(FPCore (x.re x.im y.re y.im)
  :precision binary64
  (let* ((t_0 (fma y.im y.im (* y.re y.re)))
       (t_1 (fma x.re (/ y.re t_0) (* x.im (/ y.im t_0))))
       (t_2 (/ (fma y.re (/ x.re y.im) x.im) y.im)))
  (if (<= y.im -9.8e+169)
    t_2
    (if (<= y.im -2.9e-97)
      t_1
      (if (<= y.im 4e-131)
        (/ (+ x.re (/ (* x.im y.im) y.re)) y.re)
        (if (<= y.im 1.15e+136) t_1 t_2))))))
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, y_46_im, (y_46_re * y_46_re));
	double t_1 = fma(x_46_re, (y_46_re / t_0), (x_46_im * (y_46_im / t_0)));
	double t_2 = fma(y_46_re, (x_46_re / y_46_im), x_46_im) / y_46_im;
	double tmp;
	if (y_46_im <= -9.8e+169) {
		tmp = t_2;
	} else if (y_46_im <= -2.9e-97) {
		tmp = t_1;
	} else if (y_46_im <= 4e-131) {
		tmp = (x_46_re + ((x_46_im * y_46_im) / y_46_re)) / y_46_re;
	} else if (y_46_im <= 1.15e+136) {
		tmp = t_1;
	} else {
		tmp = t_2;
	}
	return tmp;
}
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	t_0 = fma(y_46_im, y_46_im, Float64(y_46_re * y_46_re))
	t_1 = fma(x_46_re, Float64(y_46_re / t_0), Float64(x_46_im * Float64(y_46_im / t_0)))
	t_2 = Float64(fma(y_46_re, Float64(x_46_re / y_46_im), x_46_im) / y_46_im)
	tmp = 0.0
	if (y_46_im <= -9.8e+169)
		tmp = t_2;
	elseif (y_46_im <= -2.9e-97)
		tmp = t_1;
	elseif (y_46_im <= 4e-131)
		tmp = Float64(Float64(x_46_re + Float64(Float64(x_46_im * y_46_im) / y_46_re)) / y_46_re);
	elseif (y_46_im <= 1.15e+136)
		tmp = t_1;
	else
		tmp = t_2;
	end
	return tmp
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := Block[{t$95$0 = N[(y$46$im * y$46$im + N[(y$46$re * y$46$re), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(x$46$re * N[(y$46$re / t$95$0), $MachinePrecision] + N[(x$46$im * N[(y$46$im / t$95$0), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$2 = N[(N[(y$46$re * N[(x$46$re / y$46$im), $MachinePrecision] + x$46$im), $MachinePrecision] / y$46$im), $MachinePrecision]}, If[LessEqual[y$46$im, -9.8e+169], t$95$2, If[LessEqual[y$46$im, -2.9e-97], t$95$1, If[LessEqual[y$46$im, 4e-131], N[(N[(x$46$re + N[(N[(x$46$im * y$46$im), $MachinePrecision] / y$46$re), $MachinePrecision]), $MachinePrecision] / y$46$re), $MachinePrecision], If[LessEqual[y$46$im, 1.15e+136], t$95$1, t$95$2]]]]]]]
\begin{array}{l}
t_0 := \mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)\\
t_1 := \mathsf{fma}\left(x.re, \frac{y.re}{t\_0}, x.im \cdot \frac{y.im}{t\_0}\right)\\
t_2 := \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im}\\
\mathbf{if}\;y.im \leq -9.8 \cdot 10^{+169}:\\
\;\;\;\;t\_2\\

\mathbf{elif}\;y.im \leq -2.9 \cdot 10^{-97}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;y.im \leq 4 \cdot 10^{-131}:\\
\;\;\;\;\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}\\

\mathbf{elif}\;y.im \leq 1.15 \cdot 10^{+136}:\\
\;\;\;\;t\_1\\

\mathbf{else}:\\
\;\;\;\;t\_2\\


\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y.im < -9.8000000000000005e169 or 1.15e136 < y.im

    1. Initial program 61.8%

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

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

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

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
      4. lower-*.f6452.8%

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
    4. Applied rewrites52.8%

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

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

        \[\leadsto \frac{\frac{x.re \cdot y.re}{y.im} + x.im}{y.im} \]
      3. lift-/.f64N/A

        \[\leadsto \frac{\frac{x.re \cdot y.re}{y.im} + x.im}{y.im} \]
      4. lift-*.f64N/A

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

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

        \[\leadsto \frac{y.re \cdot \frac{x.re}{y.im} + x.im}{y.im} \]
      7. lower-fma.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
      8. lower-/.f6454.1%

        \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
    6. Applied rewrites54.1%

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

    if -9.8000000000000005e169 < y.im < -2.8999999999999999e-97 or 3.9999999999999999e-131 < y.im < 1.15e136

    1. Initial program 61.8%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Step-by-step derivation
      1. lift-/.f64N/A

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

        \[\leadsto \frac{\color{blue}{x.re \cdot y.re + x.im \cdot y.im}}{y.re \cdot y.re + y.im \cdot y.im} \]
      3. div-addN/A

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, \color{blue}{y.im \cdot \frac{x.im}{y.re \cdot y.re + y.im \cdot y.im}}\right) \]
      15. lower-*.f64N/A

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, \color{blue}{y.im \cdot \frac{x.im}{y.re \cdot y.re + y.im \cdot y.im}}\right) \]
      16. lower-/.f6461.5%

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

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

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

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, y.im \cdot \frac{x.im}{\color{blue}{y.im \cdot y.im} + y.re \cdot y.re}\right) \]
      20. lower-fma.f6461.5%

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, y.im \cdot \frac{x.im}{\color{blue}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}}\right) \]
    3. Applied rewrites61.5%

      \[\leadsto \color{blue}{\mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, y.im \cdot \frac{x.im}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}\right)} \]
    4. Step-by-step derivation
      1. lift-*.f64N/A

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

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

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, \color{blue}{\frac{x.im}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}} \cdot y.im\right) \]
      4. associate-*l/N/A

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

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

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, \color{blue}{x.im \cdot \frac{y.im}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}}\right) \]
      7. lower-/.f6465.0%

        \[\leadsto \mathsf{fma}\left(x.re, \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}, x.im \cdot \color{blue}{\frac{y.im}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}}\right) \]
    5. Applied rewrites65.0%

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

    if -2.8999999999999999e-97 < y.im < 3.9999999999999999e-131

    1. Initial program 61.8%

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

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    3. Step-by-step derivation
      1. lower-/.f6443.2%

        \[\leadsto \frac{x.im}{\color{blue}{y.im}} \]
    4. Applied rewrites43.2%

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    5. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    6. Step-by-step derivation
      1. lower-/.f6442.0%

        \[\leadsto \frac{x.re}{\color{blue}{y.re}} \]
    7. Applied rewrites42.0%

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    8. Taylor expanded in y.re around inf

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

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

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
      4. lower-*.f6451.1%

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
    10. Applied rewrites51.1%

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

Alternative 4: 82.0% accurate, 0.6× speedup?

\[\begin{array}{l} t_0 := \frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}\\ t_1 := \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im}\\ \mathbf{if}\;y.im \leq -6 \cdot 10^{+86}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;y.im \leq -2.9 \cdot 10^{-97}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y.im \leq 4 \cdot 10^{-131}:\\ \;\;\;\;\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}\\ \mathbf{elif}\;y.im \leq 1.1 \cdot 10^{+109}:\\ \;\;\;\;t\_0\\ \mathbf{else}:\\ \;\;\;\;t\_1\\ \end{array} \]
(FPCore (x.re x.im y.re y.im)
  :precision binary64
  (let* ((t_0
        (/
         (fma y.im x.im (* y.re x.re))
         (fma y.im y.im (* y.re y.re))))
       (t_1 (/ (fma y.re (/ x.re y.im) x.im) y.im)))
  (if (<= y.im -6e+86)
    t_1
    (if (<= y.im -2.9e-97)
      t_0
      (if (<= y.im 4e-131)
        (/ (+ x.re (/ (* x.im y.im) y.re)) y.re)
        (if (<= y.im 1.1e+109) 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)) / fma(y_46_im, y_46_im, (y_46_re * y_46_re));
	double t_1 = fma(y_46_re, (x_46_re / y_46_im), x_46_im) / y_46_im;
	double tmp;
	if (y_46_im <= -6e+86) {
		tmp = t_1;
	} else if (y_46_im <= -2.9e-97) {
		tmp = t_0;
	} else if (y_46_im <= 4e-131) {
		tmp = (x_46_re + ((x_46_im * y_46_im) / y_46_re)) / y_46_re;
	} else if (y_46_im <= 1.1e+109) {
		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)) / fma(y_46_im, y_46_im, Float64(y_46_re * y_46_re)))
	t_1 = Float64(fma(y_46_re, Float64(x_46_re / y_46_im), x_46_im) / y_46_im)
	tmp = 0.0
	if (y_46_im <= -6e+86)
		tmp = t_1;
	elseif (y_46_im <= -2.9e-97)
		tmp = t_0;
	elseif (y_46_im <= 4e-131)
		tmp = Float64(Float64(x_46_re + Float64(Float64(x_46_im * y_46_im) / y_46_re)) / y_46_re);
	elseif (y_46_im <= 1.1e+109)
		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[(y$46$im * y$46$im + N[(y$46$re * y$46$re), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(y$46$re * N[(x$46$re / y$46$im), $MachinePrecision] + x$46$im), $MachinePrecision] / y$46$im), $MachinePrecision]}, If[LessEqual[y$46$im, -6e+86], t$95$1, If[LessEqual[y$46$im, -2.9e-97], t$95$0, If[LessEqual[y$46$im, 4e-131], N[(N[(x$46$re + N[(N[(x$46$im * y$46$im), $MachinePrecision] / y$46$re), $MachinePrecision]), $MachinePrecision] / y$46$re), $MachinePrecision], If[LessEqual[y$46$im, 1.1e+109], t$95$0, t$95$1]]]]]]
\begin{array}{l}
t_0 := \frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}\\
t_1 := \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im}\\
\mathbf{if}\;y.im \leq -6 \cdot 10^{+86}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;y.im \leq -2.9 \cdot 10^{-97}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y.im \leq 4 \cdot 10^{-131}:\\
\;\;\;\;\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}\\

\mathbf{elif}\;y.im \leq 1.1 \cdot 10^{+109}:\\
\;\;\;\;t\_0\\

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


\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y.im < -5.9999999999999995e86 or 1.1e109 < y.im

    1. Initial program 61.8%

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

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

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

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
      4. lower-*.f6452.8%

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
    4. Applied rewrites52.8%

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

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

        \[\leadsto \frac{\frac{x.re \cdot y.re}{y.im} + x.im}{y.im} \]
      3. lift-/.f64N/A

        \[\leadsto \frac{\frac{x.re \cdot y.re}{y.im} + x.im}{y.im} \]
      4. lift-*.f64N/A

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

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

        \[\leadsto \frac{y.re \cdot \frac{x.re}{y.im} + x.im}{y.im} \]
      7. lower-fma.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
      8. lower-/.f6454.1%

        \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
    6. Applied rewrites54.1%

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

    if -5.9999999999999995e86 < y.im < -2.8999999999999999e-97 or 3.9999999999999999e-131 < y.im < 1.1e109

    1. Initial program 61.8%

      \[\frac{x.re \cdot y.re + x.im \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \]
    2. Step-by-step derivation
      1. lift-+.f64N/A

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

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

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

        \[\leadsto \frac{\color{blue}{y.im \cdot x.im} + x.re \cdot y.re}{y.re \cdot y.re + y.im \cdot y.im} \]
      5. lower-fma.f6461.8%

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

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

        \[\leadsto \frac{\mathsf{fma}\left(y.im, x.im, \color{blue}{y.re \cdot x.re}\right)}{y.re \cdot y.re + y.im \cdot y.im} \]
      8. lower-*.f6461.8%

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

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

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

        \[\leadsto \frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{\color{blue}{y.im \cdot y.im} + y.re \cdot y.re} \]
      12. lower-fma.f6461.8%

        \[\leadsto \frac{\mathsf{fma}\left(y.im, x.im, y.re \cdot x.re\right)}{\color{blue}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}} \]
    3. Applied rewrites61.8%

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

    if -2.8999999999999999e-97 < y.im < 3.9999999999999999e-131

    1. Initial program 61.8%

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

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    3. Step-by-step derivation
      1. lower-/.f6443.2%

        \[\leadsto \frac{x.im}{\color{blue}{y.im}} \]
    4. Applied rewrites43.2%

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    5. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    6. Step-by-step derivation
      1. lower-/.f6442.0%

        \[\leadsto \frac{x.re}{\color{blue}{y.re}} \]
    7. Applied rewrites42.0%

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    8. Taylor expanded in y.re around inf

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

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

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
      4. lower-*.f6451.1%

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
    10. Applied rewrites51.1%

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

Alternative 5: 77.6% accurate, 1.0× speedup?

\[\begin{array}{l} t_0 := \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im}\\ \mathbf{if}\;y.im \leq -3.6 \cdot 10^{+30}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y.im \leq 0.045:\\ \;\;\;\;\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \]
(FPCore (x.re x.im y.re y.im)
  :precision binary64
  (let* ((t_0 (/ (fma y.re (/ x.re y.im) x.im) y.im)))
  (if (<= y.im -3.6e+30)
    t_0
    (if (<= y.im 0.045)
      (/ (+ x.re (/ (* x.im y.im) y.re)) y.re)
      t_0))))
double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	double t_0 = fma(y_46_re, (x_46_re / y_46_im), x_46_im) / y_46_im;
	double tmp;
	if (y_46_im <= -3.6e+30) {
		tmp = t_0;
	} else if (y_46_im <= 0.045) {
		tmp = (x_46_re + ((x_46_im * y_46_im) / y_46_re)) / y_46_re;
	} else {
		tmp = t_0;
	}
	return tmp;
}
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	t_0 = Float64(fma(y_46_re, Float64(x_46_re / y_46_im), x_46_im) / y_46_im)
	tmp = 0.0
	if (y_46_im <= -3.6e+30)
		tmp = t_0;
	elseif (y_46_im <= 0.045)
		tmp = Float64(Float64(x_46_re + Float64(Float64(x_46_im * y_46_im) / y_46_re)) / y_46_re);
	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[(y$46$re * N[(x$46$re / y$46$im), $MachinePrecision] + x$46$im), $MachinePrecision] / y$46$im), $MachinePrecision]}, If[LessEqual[y$46$im, -3.6e+30], t$95$0, If[LessEqual[y$46$im, 0.045], N[(N[(x$46$re + N[(N[(x$46$im * y$46$im), $MachinePrecision] / y$46$re), $MachinePrecision]), $MachinePrecision] / y$46$re), $MachinePrecision], t$95$0]]]
\begin{array}{l}
t_0 := \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im}\\
\mathbf{if}\;y.im \leq -3.6 \cdot 10^{+30}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y.im \leq 0.045:\\
\;\;\;\;\frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re}\\

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


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y.im < -3.6000000000000002e30 or 0.044999999999999998 < y.im

    1. Initial program 61.8%

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

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

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

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
      4. lower-*.f6452.8%

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
    4. Applied rewrites52.8%

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

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

        \[\leadsto \frac{\frac{x.re \cdot y.re}{y.im} + x.im}{y.im} \]
      3. lift-/.f64N/A

        \[\leadsto \frac{\frac{x.re \cdot y.re}{y.im} + x.im}{y.im} \]
      4. lift-*.f64N/A

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

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

        \[\leadsto \frac{y.re \cdot \frac{x.re}{y.im} + x.im}{y.im} \]
      7. lower-fma.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
      8. lower-/.f6454.1%

        \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
    6. Applied rewrites54.1%

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

    if -3.6000000000000002e30 < y.im < 0.044999999999999998

    1. Initial program 61.8%

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

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    3. Step-by-step derivation
      1. lower-/.f6443.2%

        \[\leadsto \frac{x.im}{\color{blue}{y.im}} \]
    4. Applied rewrites43.2%

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    5. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    6. Step-by-step derivation
      1. lower-/.f6442.0%

        \[\leadsto \frac{x.re}{\color{blue}{y.re}} \]
    7. Applied rewrites42.0%

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    8. Taylor expanded in y.re around inf

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

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

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
      4. lower-*.f6451.1%

        \[\leadsto \frac{x.re + \frac{x.im \cdot y.im}{y.re}}{y.re} \]
    10. Applied rewrites51.1%

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

Alternative 6: 72.4% accurate, 1.0× speedup?

\[\begin{array}{l} \mathbf{if}\;y.re \leq -4 \cdot 10^{-26}:\\ \;\;\;\;\frac{x.re}{y.re}\\ \mathbf{elif}\;y.re \leq 2.4 \cdot 10^{+69}:\\ \;\;\;\;\frac{\mathsf{fma}\left(\frac{y.re}{y.im}, x.re, x.im\right)}{y.im}\\ \mathbf{else}:\\ \;\;\;\;\frac{x.re}{y.re}\\ \end{array} \]
(FPCore (x.re x.im y.re y.im)
  :precision binary64
  (if (<= y.re -4e-26)
  (/ x.re y.re)
  (if (<= y.re 2.4e+69)
    (/ (fma (/ y.re y.im) x.re 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 <= -4e-26) {
		tmp = x_46_re / y_46_re;
	} else if (y_46_re <= 2.4e+69) {
		tmp = fma((y_46_re / y_46_im), x_46_re, 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 <= -4e-26)
		tmp = Float64(x_46_re / y_46_re);
	elseif (y_46_re <= 2.4e+69)
		tmp = Float64(fma(Float64(y_46_re / y_46_im), x_46_re, x_46_im) / y_46_im);
	else
		tmp = Float64(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, -4e-26], N[(x$46$re / y$46$re), $MachinePrecision], If[LessEqual[y$46$re, 2.4e+69], N[(N[(N[(y$46$re / y$46$im), $MachinePrecision] * x$46$re + x$46$im), $MachinePrecision] / y$46$im), $MachinePrecision], N[(x$46$re / y$46$re), $MachinePrecision]]]
\begin{array}{l}
\mathbf{if}\;y.re \leq -4 \cdot 10^{-26}:\\
\;\;\;\;\frac{x.re}{y.re}\\

\mathbf{elif}\;y.re \leq 2.4 \cdot 10^{+69}:\\
\;\;\;\;\frac{\mathsf{fma}\left(\frac{y.re}{y.im}, x.re, x.im\right)}{y.im}\\

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


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y.re < -4.0000000000000002e-26 or 2.4000000000000002e69 < y.re

    1. Initial program 61.8%

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

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    3. Step-by-step derivation
      1. lower-/.f6443.2%

        \[\leadsto \frac{x.im}{\color{blue}{y.im}} \]
    4. Applied rewrites43.2%

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    5. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    6. Step-by-step derivation
      1. lower-/.f6442.0%

        \[\leadsto \frac{x.re}{\color{blue}{y.re}} \]
    7. Applied rewrites42.0%

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

    if -4.0000000000000002e-26 < y.re < 2.4000000000000002e69

    1. Initial program 61.8%

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

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

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

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
      4. lower-*.f6452.8%

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
    4. Applied rewrites52.8%

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

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

        \[\leadsto \frac{\frac{x.re \cdot y.re}{y.im} + x.im}{y.im} \]
      3. lift-/.f64N/A

        \[\leadsto \frac{\frac{x.re \cdot y.re}{y.im} + x.im}{y.im} \]
      4. lift-*.f64N/A

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

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

        \[\leadsto \frac{y.re \cdot \frac{x.re}{y.im} + x.im}{y.im} \]
      7. lower-fma.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
      8. lower-/.f6454.1%

        \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
    6. Applied rewrites54.1%

      \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
    7. Step-by-step derivation
      1. lift-fma.f64N/A

        \[\leadsto \frac{y.re \cdot \frac{x.re}{y.im} + x.im}{y.im} \]
      2. lift-/.f64N/A

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

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

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

        \[\leadsto \frac{x.re \cdot \frac{y.re}{y.im} + x.im}{y.im} \]
      6. lift-/.f64N/A

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

        \[\leadsto \frac{\frac{y.re}{y.im} \cdot x.re + x.im}{y.im} \]
      8. lower-fma.f6454.9%

        \[\leadsto \frac{\mathsf{fma}\left(\frac{y.re}{y.im}, x.re, x.im\right)}{y.im} \]
    8. Applied rewrites54.9%

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

Alternative 7: 69.1% accurate, 1.0× speedup?

\[\begin{array}{l} t_0 := \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im}\\ \mathbf{if}\;y.im \leq -3.6 \cdot 10^{+30}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y.im \leq 0.045:\\ \;\;\;\;\frac{x.re}{y.re}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \]
(FPCore (x.re x.im y.re y.im)
  :precision binary64
  (let* ((t_0 (/ (fma y.re (/ x.re y.im) x.im) y.im)))
  (if (<= y.im -3.6e+30) t_0 (if (<= y.im 0.045) (/ x.re y.re) t_0))))
double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	double t_0 = fma(y_46_re, (x_46_re / y_46_im), x_46_im) / y_46_im;
	double tmp;
	if (y_46_im <= -3.6e+30) {
		tmp = t_0;
	} else if (y_46_im <= 0.045) {
		tmp = x_46_re / y_46_re;
	} else {
		tmp = t_0;
	}
	return tmp;
}
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	t_0 = Float64(fma(y_46_re, Float64(x_46_re / y_46_im), x_46_im) / y_46_im)
	tmp = 0.0
	if (y_46_im <= -3.6e+30)
		tmp = t_0;
	elseif (y_46_im <= 0.045)
		tmp = Float64(x_46_re / y_46_re);
	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[(y$46$re * N[(x$46$re / y$46$im), $MachinePrecision] + x$46$im), $MachinePrecision] / y$46$im), $MachinePrecision]}, If[LessEqual[y$46$im, -3.6e+30], t$95$0, If[LessEqual[y$46$im, 0.045], N[(x$46$re / y$46$re), $MachinePrecision], t$95$0]]]
\begin{array}{l}
t_0 := \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im}\\
\mathbf{if}\;y.im \leq -3.6 \cdot 10^{+30}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y.im \leq 0.045:\\
\;\;\;\;\frac{x.re}{y.re}\\

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


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y.im < -3.6000000000000002e30 or 0.044999999999999998 < y.im

    1. Initial program 61.8%

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

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

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

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
      3. lower-/.f64N/A

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
      4. lower-*.f6452.8%

        \[\leadsto \frac{x.im + \frac{x.re \cdot y.re}{y.im}}{y.im} \]
    4. Applied rewrites52.8%

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

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

        \[\leadsto \frac{\frac{x.re \cdot y.re}{y.im} + x.im}{y.im} \]
      3. lift-/.f64N/A

        \[\leadsto \frac{\frac{x.re \cdot y.re}{y.im} + x.im}{y.im} \]
      4. lift-*.f64N/A

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

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

        \[\leadsto \frac{y.re \cdot \frac{x.re}{y.im} + x.im}{y.im} \]
      7. lower-fma.f64N/A

        \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
      8. lower-/.f6454.1%

        \[\leadsto \frac{\mathsf{fma}\left(y.re, \frac{x.re}{y.im}, x.im\right)}{y.im} \]
    6. Applied rewrites54.1%

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

    if -3.6000000000000002e30 < y.im < 0.044999999999999998

    1. Initial program 61.8%

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

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    3. Step-by-step derivation
      1. lower-/.f6443.2%

        \[\leadsto \frac{x.im}{\color{blue}{y.im}} \]
    4. Applied rewrites43.2%

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    5. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    6. Step-by-step derivation
      1. lower-/.f6442.0%

        \[\leadsto \frac{x.re}{\color{blue}{y.re}} \]
    7. Applied rewrites42.0%

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

Alternative 8: 63.2% accurate, 1.8× speedup?

\[\begin{array}{l} \mathbf{if}\;y.im \leq -3.7 \cdot 10^{+33}:\\ \;\;\;\;\frac{x.im}{y.im}\\ \mathbf{elif}\;y.im \leq 0.045:\\ \;\;\;\;\frac{x.re}{y.re}\\ \mathbf{else}:\\ \;\;\;\;\frac{x.im}{y.im}\\ \end{array} \]
(FPCore (x.re x.im y.re y.im)
  :precision binary64
  (if (<= y.im -3.7e+33)
  (/ x.im y.im)
  (if (<= y.im 0.045) (/ x.re y.re) (/ x.im y.im))))
double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	double tmp;
	if (y_46_im <= -3.7e+33) {
		tmp = x_46_im / y_46_im;
	} else if (y_46_im <= 0.045) {
		tmp = x_46_re / y_46_re;
	} else {
		tmp = x_46_im / y_46_im;
	}
	return tmp;
}
real(8) function code(x_46re, x_46im, y_46re, y_46im)
use fmin_fmax_functions
    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_46im <= (-3.7d+33)) then
        tmp = x_46im / y_46im
    else if (y_46im <= 0.045d0) then
        tmp = x_46re / y_46re
    else
        tmp = x_46im / y_46im
    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_im <= -3.7e+33) {
		tmp = x_46_im / y_46_im;
	} else if (y_46_im <= 0.045) {
		tmp = x_46_re / y_46_re;
	} else {
		tmp = x_46_im / y_46_im;
	}
	return tmp;
}
def code(x_46_re, x_46_im, y_46_re, y_46_im):
	tmp = 0
	if y_46_im <= -3.7e+33:
		tmp = x_46_im / y_46_im
	elif y_46_im <= 0.045:
		tmp = x_46_re / y_46_re
	else:
		tmp = x_46_im / y_46_im
	return tmp
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	tmp = 0.0
	if (y_46_im <= -3.7e+33)
		tmp = Float64(x_46_im / y_46_im);
	elseif (y_46_im <= 0.045)
		tmp = Float64(x_46_re / y_46_re);
	else
		tmp = Float64(x_46_im / y_46_im);
	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_im <= -3.7e+33)
		tmp = x_46_im / y_46_im;
	elseif (y_46_im <= 0.045)
		tmp = x_46_re / y_46_re;
	else
		tmp = x_46_im / y_46_im;
	end
	tmp_2 = tmp;
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := If[LessEqual[y$46$im, -3.7e+33], N[(x$46$im / y$46$im), $MachinePrecision], If[LessEqual[y$46$im, 0.045], N[(x$46$re / y$46$re), $MachinePrecision], N[(x$46$im / y$46$im), $MachinePrecision]]]
\begin{array}{l}
\mathbf{if}\;y.im \leq -3.7 \cdot 10^{+33}:\\
\;\;\;\;\frac{x.im}{y.im}\\

\mathbf{elif}\;y.im \leq 0.045:\\
\;\;\;\;\frac{x.re}{y.re}\\

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


\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y.im < -3.6999999999999999e33 or 0.044999999999999998 < y.im

    1. Initial program 61.8%

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

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    3. Step-by-step derivation
      1. lower-/.f6443.2%

        \[\leadsto \frac{x.im}{\color{blue}{y.im}} \]
    4. Applied rewrites43.2%

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

    if -3.6999999999999999e33 < y.im < 0.044999999999999998

    1. Initial program 61.8%

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

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    3. Step-by-step derivation
      1. lower-/.f6443.2%

        \[\leadsto \frac{x.im}{\color{blue}{y.im}} \]
    4. Applied rewrites43.2%

      \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
    5. Taylor expanded in y.re around inf

      \[\leadsto \color{blue}{\frac{x.re}{y.re}} \]
    6. Step-by-step derivation
      1. lower-/.f6442.0%

        \[\leadsto \frac{x.re}{\color{blue}{y.re}} \]
    7. Applied rewrites42.0%

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

Alternative 9: 43.2% accurate, 4.6× speedup?

\[\frac{x.im}{y.im} \]
(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)
use fmin_fmax_functions
    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]
\frac{x.im}{y.im}
Derivation
  1. Initial program 61.8%

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

    \[\leadsto \color{blue}{\frac{x.im}{y.im}} \]
  3. Step-by-step derivation
    1. lower-/.f6443.2%

      \[\leadsto \frac{x.im}{\color{blue}{y.im}} \]
  4. Applied rewrites43.2%

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

Reproduce

?
herbie shell --seed 2025313 -o setup:search
(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))))