_divideComplex, imaginary part

Percentage Accurate: 61.6% → 82.6%
Time: 3.9s
Alternatives: 9
Speedup: 1.3×

Specification

?
\[\begin{array}{l} \\ \frac{x.im \cdot y.re - x.re \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (/ (- (* x.im y.re) (* x.re 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_im * y_46_re) - (x_46_re * y_46_im)) / ((y_46_re * y_46_re) + (y_46_im * y_46_im));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

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_46re) - (x_46re * 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_im * y_46_re) - (x_46_re * 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_im * y_46_re) - (x_46_re * 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_im * y_46_re) - Float64(x_46_re * 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_im * y_46_re) - (x_46_re * 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$46$im * y$46$re), $MachinePrecision] - N[(x$46$re * 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.im \cdot y.re - x.re \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im}
\end{array}

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: 61.6% accurate, 1.0× speedup?

\[\begin{array}{l} \\ \frac{x.im \cdot y.re - x.re \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (/ (- (* x.im y.re) (* x.re 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_im * y_46_re) - (x_46_re * y_46_im)) / ((y_46_re * y_46_re) + (y_46_im * y_46_im));
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

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_46re) - (x_46re * 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_im * y_46_re) - (x_46_re * 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_im * y_46_re) - (x_46_re * 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_im * y_46_re) - Float64(x_46_re * 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_im * y_46_re) - (x_46_re * 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$46$im * y$46$re), $MachinePrecision] - N[(x$46$re * 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.im \cdot y.re - x.re \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im}
\end{array}

Alternative 1: 82.6% accurate, 0.4× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{y.re}, \frac{x.im}{y.re}\right)\\ t_1 := \frac{x.im \cdot y.re - x.re \cdot y.im}{\mathsf{fma}\left(y.re, y.re, y.im \cdot y.im\right)}\\ \mathbf{if}\;y.re \leq -1.65 \cdot 10^{+129}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y.re \leq -5.5 \cdot 10^{+31}:\\ \;\;\;\;\mathsf{fma}\left(\frac{x.im}{y.im}, \frac{y.re}{y.im}, \frac{-x.re}{y.im}\right)\\ \mathbf{elif}\;y.re \leq -1.1 \cdot 10^{-90}:\\ \;\;\;\;t\_1\\ \mathbf{elif}\;y.re \leq 5.5 \cdot 10^{-152}:\\ \;\;\;\;-\frac{\mathsf{fma}\left(\frac{y.re \cdot x.im}{y.im}, -1, x.re\right)}{y.im}\\ \mathbf{elif}\;y.re \leq 4 \cdot 10^{+96}:\\ \;\;\;\;t\_1\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (let* ((t_0 (fma (/ (- x.re) y.re) (/ y.im y.re) (/ x.im y.re)))
        (t_1
         (/ (- (* x.im y.re) (* x.re y.im)) (fma y.re y.re (* y.im y.im)))))
   (if (<= y.re -1.65e+129)
     t_0
     (if (<= y.re -5.5e+31)
       (fma (/ x.im y.im) (/ y.re y.im) (/ (- x.re) y.im))
       (if (<= y.re -1.1e-90)
         t_1
         (if (<= y.re 5.5e-152)
           (- (/ (fma (/ (* y.re x.im) y.im) -1.0 x.re) y.im))
           (if (<= y.re 4e+96) t_1 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_re / y_46_re), (y_46_im / y_46_re), (x_46_im / y_46_re));
	double t_1 = ((x_46_im * y_46_re) - (x_46_re * y_46_im)) / fma(y_46_re, y_46_re, (y_46_im * y_46_im));
	double tmp;
	if (y_46_re <= -1.65e+129) {
		tmp = t_0;
	} else if (y_46_re <= -5.5e+31) {
		tmp = fma((x_46_im / y_46_im), (y_46_re / y_46_im), (-x_46_re / y_46_im));
	} else if (y_46_re <= -1.1e-90) {
		tmp = t_1;
	} else if (y_46_re <= 5.5e-152) {
		tmp = -(fma(((y_46_re * x_46_im) / y_46_im), -1.0, x_46_re) / y_46_im);
	} else if (y_46_re <= 4e+96) {
		tmp = t_1;
	} else {
		tmp = t_0;
	}
	return tmp;
}
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	t_0 = fma(Float64(Float64(-x_46_re) / y_46_re), Float64(y_46_im / y_46_re), Float64(x_46_im / y_46_re))
	t_1 = Float64(Float64(Float64(x_46_im * y_46_re) - Float64(x_46_re * y_46_im)) / fma(y_46_re, y_46_re, Float64(y_46_im * y_46_im)))
	tmp = 0.0
	if (y_46_re <= -1.65e+129)
		tmp = t_0;
	elseif (y_46_re <= -5.5e+31)
		tmp = fma(Float64(x_46_im / y_46_im), Float64(y_46_re / y_46_im), Float64(Float64(-x_46_re) / y_46_im));
	elseif (y_46_re <= -1.1e-90)
		tmp = t_1;
	elseif (y_46_re <= 5.5e-152)
		tmp = Float64(-Float64(fma(Float64(Float64(y_46_re * x_46_im) / y_46_im), -1.0, x_46_re) / y_46_im));
	elseif (y_46_re <= 4e+96)
		tmp = t_1;
	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$46$re) / y$46$re), $MachinePrecision] * N[(y$46$im / y$46$re), $MachinePrecision] + N[(x$46$im / y$46$re), $MachinePrecision]), $MachinePrecision]}, Block[{t$95$1 = N[(N[(N[(x$46$im * y$46$re), $MachinePrecision] - N[(x$46$re * y$46$im), $MachinePrecision]), $MachinePrecision] / N[(y$46$re * y$46$re + N[(y$46$im * y$46$im), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y$46$re, -1.65e+129], t$95$0, If[LessEqual[y$46$re, -5.5e+31], N[(N[(x$46$im / y$46$im), $MachinePrecision] * N[(y$46$re / y$46$im), $MachinePrecision] + N[((-x$46$re) / y$46$im), $MachinePrecision]), $MachinePrecision], If[LessEqual[y$46$re, -1.1e-90], t$95$1, If[LessEqual[y$46$re, 5.5e-152], (-N[(N[(N[(N[(y$46$re * x$46$im), $MachinePrecision] / y$46$im), $MachinePrecision] * -1.0 + x$46$re), $MachinePrecision] / y$46$im), $MachinePrecision]), If[LessEqual[y$46$re, 4e+96], t$95$1, t$95$0]]]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{y.re}, \frac{x.im}{y.re}\right)\\
t_1 := \frac{x.im \cdot y.re - x.re \cdot y.im}{\mathsf{fma}\left(y.re, y.re, y.im \cdot y.im\right)}\\
\mathbf{if}\;y.re \leq -1.65 \cdot 10^{+129}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y.re \leq -5.5 \cdot 10^{+31}:\\
\;\;\;\;\mathsf{fma}\left(\frac{x.im}{y.im}, \frac{y.re}{y.im}, \frac{-x.re}{y.im}\right)\\

\mathbf{elif}\;y.re \leq -1.1 \cdot 10^{-90}:\\
\;\;\;\;t\_1\\

\mathbf{elif}\;y.re \leq 5.5 \cdot 10^{-152}:\\
\;\;\;\;-\frac{\mathsf{fma}\left(\frac{y.re \cdot x.im}{y.im}, -1, x.re\right)}{y.im}\\

\mathbf{elif}\;y.re \leq 4 \cdot 10^{+96}:\\
\;\;\;\;t\_1\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 4 regimes
  2. if y.re < -1.64999999999999995e129 or 4.0000000000000002e96 < y.re

    1. Initial program 35.3%

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

      \[\leadsto \color{blue}{-1 \cdot \frac{x.re \cdot y.im}{{y.re}^{2}} + \frac{x.im}{y.re}} \]
    3. Step-by-step derivation
      1. associate-*r/N/A

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

        \[\leadsto \frac{\left(-1 \cdot x.re\right) \cdot y.im}{{y.re}^{2}} + \frac{x.im}{y.re} \]
      3. pow2N/A

        \[\leadsto \frac{\left(-1 \cdot x.re\right) \cdot y.im}{y.re \cdot y.re} + \frac{x.im}{y.re} \]
      4. times-fracN/A

        \[\leadsto \frac{-1 \cdot x.re}{y.re} \cdot \frac{y.im}{y.re} + \frac{\color{blue}{x.im}}{y.re} \]
      5. lower-fma.f64N/A

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{\color{blue}{y.re}}, \frac{x.im}{y.re}\right) \]
      10. lower-/.f6485.5

        \[\leadsto \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{y.re}, \frac{x.im}{y.re}\right) \]
    4. Applied rewrites85.5%

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

    if -1.64999999999999995e129 < y.re < -5.50000000000000002e31

    1. Initial program 72.2%

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

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

        \[\leadsto \frac{x.im \cdot y.re}{{y.im}^{2}} + \color{blue}{-1 \cdot \frac{x.re}{y.im}} \]
      2. pow2N/A

        \[\leadsto \frac{x.im \cdot y.re}{y.im \cdot y.im} + -1 \cdot \frac{x.re}{y.im} \]
      3. times-fracN/A

        \[\leadsto \frac{x.im}{y.im} \cdot \frac{y.re}{y.im} + \color{blue}{-1} \cdot \frac{x.re}{y.im} \]
      4. lower-fma.f64N/A

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{x.im}{y.im}, \frac{y.re}{y.im}, \frac{-1 \cdot x.re}{y.im}\right) \]
      9. mul-1-negN/A

        \[\leadsto \mathsf{fma}\left(\frac{x.im}{y.im}, \frac{y.re}{y.im}, \frac{\mathsf{neg}\left(x.re\right)}{y.im}\right) \]
      10. lower-neg.f6435.2

        \[\leadsto \mathsf{fma}\left(\frac{x.im}{y.im}, \frac{y.re}{y.im}, \frac{-x.re}{y.im}\right) \]
    4. Applied rewrites35.2%

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

    if -5.50000000000000002e31 < y.re < -1.09999999999999993e-90 or 5.4999999999999998e-152 < y.re < 4.0000000000000002e96

    1. Initial program 76.8%

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

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

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

        \[\leadsto \frac{x.im \cdot y.re - x.re \cdot y.im}{y.re \cdot y.re + \color{blue}{y.im \cdot y.im}} \]
      4. pow2N/A

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

        \[\leadsto \frac{x.im \cdot y.re - x.re \cdot y.im}{\color{blue}{\mathsf{fma}\left(y.re, y.re, {y.im}^{2}\right)}} \]
      6. pow2N/A

        \[\leadsto \frac{x.im \cdot y.re - x.re \cdot y.im}{\mathsf{fma}\left(y.re, y.re, \color{blue}{y.im \cdot y.im}\right)} \]
      7. lift-*.f6476.8

        \[\leadsto \frac{x.im \cdot y.re - x.re \cdot y.im}{\mathsf{fma}\left(y.re, y.re, \color{blue}{y.im \cdot y.im}\right)} \]
    3. Applied rewrites76.8%

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

    if -1.09999999999999993e-90 < y.re < 5.4999999999999998e-152

    1. Initial program 70.7%

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

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

        \[\leadsto \mathsf{neg}\left(\frac{x.re + -1 \cdot \frac{x.im \cdot y.re}{y.im}}{y.im}\right) \]
      2. lower-neg.f64N/A

        \[\leadsto -\frac{x.re + -1 \cdot \frac{x.im \cdot y.re}{y.im}}{y.im} \]
      3. lower-/.f64N/A

        \[\leadsto -\frac{x.re + -1 \cdot \frac{x.im \cdot y.re}{y.im}}{y.im} \]
      4. +-commutativeN/A

        \[\leadsto -\frac{-1 \cdot \frac{x.im \cdot y.re}{y.im} + x.re}{y.im} \]
      5. *-commutativeN/A

        \[\leadsto -\frac{\frac{x.im \cdot y.re}{y.im} \cdot -1 + x.re}{y.im} \]
      6. lower-fma.f64N/A

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

        \[\leadsto -\frac{\mathsf{fma}\left(\frac{x.im \cdot y.re}{y.im}, -1, x.re\right)}{y.im} \]
      8. *-commutativeN/A

        \[\leadsto -\frac{\mathsf{fma}\left(\frac{y.re \cdot x.im}{y.im}, -1, x.re\right)}{y.im} \]
      9. lower-*.f6491.3

        \[\leadsto -\frac{\mathsf{fma}\left(\frac{y.re \cdot x.im}{y.im}, -1, x.re\right)}{y.im} \]
    4. Applied rewrites91.3%

      \[\leadsto \color{blue}{-\frac{\mathsf{fma}\left(\frac{y.re \cdot x.im}{y.im}, -1, x.re\right)}{y.im}} \]
  3. Recombined 4 regimes into one program.
  4. Add Preprocessing

Alternative 2: 80.6% accurate, 0.5× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{y.re}, \frac{x.im}{y.re}\right)\\ \mathbf{if}\;y.re \leq -1.85 \cdot 10^{+142}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y.re \leq -1.25 \cdot 10^{-90}:\\ \;\;\;\;\left(-x.im\right) \cdot \frac{\mathsf{fma}\left(x.re, \frac{y.im}{x.im}, -y.re\right)}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}\\ \mathbf{elif}\;y.re \leq 5.5 \cdot 10^{-152}:\\ \;\;\;\;-\frac{\mathsf{fma}\left(\frac{y.re \cdot x.im}{y.im}, -1, x.re\right)}{y.im}\\ \mathbf{elif}\;y.re \leq 4 \cdot 10^{+96}:\\ \;\;\;\;\frac{x.im \cdot y.re - x.re \cdot y.im}{\mathsf{fma}\left(y.re, y.re, y.im \cdot y.im\right)}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (let* ((t_0 (fma (/ (- x.re) y.re) (/ y.im y.re) (/ x.im y.re))))
   (if (<= y.re -1.85e+142)
     t_0
     (if (<= y.re -1.25e-90)
       (*
        (- x.im)
        (/ (fma x.re (/ y.im x.im) (- y.re)) (fma y.im y.im (* y.re y.re))))
       (if (<= y.re 5.5e-152)
         (- (/ (fma (/ (* y.re x.im) y.im) -1.0 x.re) y.im))
         (if (<= y.re 4e+96)
           (/ (- (* x.im y.re) (* x.re y.im)) (fma y.re y.re (* y.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_re / y_46_re), (y_46_im / y_46_re), (x_46_im / y_46_re));
	double tmp;
	if (y_46_re <= -1.85e+142) {
		tmp = t_0;
	} else if (y_46_re <= -1.25e-90) {
		tmp = -x_46_im * (fma(x_46_re, (y_46_im / x_46_im), -y_46_re) / fma(y_46_im, y_46_im, (y_46_re * y_46_re)));
	} else if (y_46_re <= 5.5e-152) {
		tmp = -(fma(((y_46_re * x_46_im) / y_46_im), -1.0, x_46_re) / y_46_im);
	} else if (y_46_re <= 4e+96) {
		tmp = ((x_46_im * y_46_re) - (x_46_re * y_46_im)) / fma(y_46_re, y_46_re, (y_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 = fma(Float64(Float64(-x_46_re) / y_46_re), Float64(y_46_im / y_46_re), Float64(x_46_im / y_46_re))
	tmp = 0.0
	if (y_46_re <= -1.85e+142)
		tmp = t_0;
	elseif (y_46_re <= -1.25e-90)
		tmp = Float64(Float64(-x_46_im) * Float64(fma(x_46_re, Float64(y_46_im / x_46_im), Float64(-y_46_re)) / fma(y_46_im, y_46_im, Float64(y_46_re * y_46_re))));
	elseif (y_46_re <= 5.5e-152)
		tmp = Float64(-Float64(fma(Float64(Float64(y_46_re * x_46_im) / y_46_im), -1.0, x_46_re) / y_46_im));
	elseif (y_46_re <= 4e+96)
		tmp = Float64(Float64(Float64(x_46_im * y_46_re) - Float64(x_46_re * y_46_im)) / fma(y_46_re, y_46_re, Float64(y_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$46$re) / y$46$re), $MachinePrecision] * N[(y$46$im / y$46$re), $MachinePrecision] + N[(x$46$im / y$46$re), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y$46$re, -1.85e+142], t$95$0, If[LessEqual[y$46$re, -1.25e-90], N[((-x$46$im) * N[(N[(x$46$re * N[(y$46$im / x$46$im), $MachinePrecision] + (-y$46$re)), $MachinePrecision] / N[(y$46$im * y$46$im + N[(y$46$re * y$46$re), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], If[LessEqual[y$46$re, 5.5e-152], (-N[(N[(N[(N[(y$46$re * x$46$im), $MachinePrecision] / y$46$im), $MachinePrecision] * -1.0 + x$46$re), $MachinePrecision] / y$46$im), $MachinePrecision]), If[LessEqual[y$46$re, 4e+96], N[(N[(N[(x$46$im * y$46$re), $MachinePrecision] - N[(x$46$re * y$46$im), $MachinePrecision]), $MachinePrecision] / N[(y$46$re * y$46$re + N[(y$46$im * y$46$im), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$0]]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{y.re}, \frac{x.im}{y.re}\right)\\
\mathbf{if}\;y.re \leq -1.85 \cdot 10^{+142}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y.re \leq -1.25 \cdot 10^{-90}:\\
\;\;\;\;\left(-x.im\right) \cdot \frac{\mathsf{fma}\left(x.re, \frac{y.im}{x.im}, -y.re\right)}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}\\

\mathbf{elif}\;y.re \leq 5.5 \cdot 10^{-152}:\\
\;\;\;\;-\frac{\mathsf{fma}\left(\frac{y.re \cdot x.im}{y.im}, -1, x.re\right)}{y.im}\\

\mathbf{elif}\;y.re \leq 4 \cdot 10^{+96}:\\
\;\;\;\;\frac{x.im \cdot y.re - x.re \cdot y.im}{\mathsf{fma}\left(y.re, y.re, y.im \cdot y.im\right)}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 4 regimes
  2. if y.re < -1.8499999999999999e142 or 4.0000000000000002e96 < y.re

    1. Initial program 34.6%

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

      \[\leadsto \color{blue}{-1 \cdot \frac{x.re \cdot y.im}{{y.re}^{2}} + \frac{x.im}{y.re}} \]
    3. Step-by-step derivation
      1. associate-*r/N/A

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

        \[\leadsto \frac{\left(-1 \cdot x.re\right) \cdot y.im}{{y.re}^{2}} + \frac{x.im}{y.re} \]
      3. pow2N/A

        \[\leadsto \frac{\left(-1 \cdot x.re\right) \cdot y.im}{y.re \cdot y.re} + \frac{x.im}{y.re} \]
      4. times-fracN/A

        \[\leadsto \frac{-1 \cdot x.re}{y.re} \cdot \frac{y.im}{y.re} + \frac{\color{blue}{x.im}}{y.re} \]
      5. lower-fma.f64N/A

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{\color{blue}{y.re}}, \frac{x.im}{y.re}\right) \]
      10. lower-/.f6486.4

        \[\leadsto \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{y.re}, \frac{x.im}{y.re}\right) \]
    4. Applied rewrites86.4%

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

    if -1.8499999999999999e142 < y.re < -1.25000000000000005e-90

    1. Initial program 73.8%

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

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

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

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

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

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

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

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

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

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

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

        \[\leadsto \left(-x.im\right) \cdot \frac{-1 \cdot y.re + \frac{x.re \cdot y.im}{x.im}}{\color{blue}{{y.im}^{2} + {y.re}^{2}}} \]
    4. Applied rewrites68.4%

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

    if -1.25000000000000005e-90 < y.re < 5.4999999999999998e-152

    1. Initial program 70.7%

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

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

        \[\leadsto \mathsf{neg}\left(\frac{x.re + -1 \cdot \frac{x.im \cdot y.re}{y.im}}{y.im}\right) \]
      2. lower-neg.f64N/A

        \[\leadsto -\frac{x.re + -1 \cdot \frac{x.im \cdot y.re}{y.im}}{y.im} \]
      3. lower-/.f64N/A

        \[\leadsto -\frac{x.re + -1 \cdot \frac{x.im \cdot y.re}{y.im}}{y.im} \]
      4. +-commutativeN/A

        \[\leadsto -\frac{-1 \cdot \frac{x.im \cdot y.re}{y.im} + x.re}{y.im} \]
      5. *-commutativeN/A

        \[\leadsto -\frac{\frac{x.im \cdot y.re}{y.im} \cdot -1 + x.re}{y.im} \]
      6. lower-fma.f64N/A

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

        \[\leadsto -\frac{\mathsf{fma}\left(\frac{x.im \cdot y.re}{y.im}, -1, x.re\right)}{y.im} \]
      8. *-commutativeN/A

        \[\leadsto -\frac{\mathsf{fma}\left(\frac{y.re \cdot x.im}{y.im}, -1, x.re\right)}{y.im} \]
      9. lower-*.f6491.3

        \[\leadsto -\frac{\mathsf{fma}\left(\frac{y.re \cdot x.im}{y.im}, -1, x.re\right)}{y.im} \]
    4. Applied rewrites91.3%

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

    if 5.4999999999999998e-152 < y.re < 4.0000000000000002e96

    1. Initial program 76.9%

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

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

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

        \[\leadsto \frac{x.im \cdot y.re - x.re \cdot y.im}{y.re \cdot y.re + \color{blue}{y.im \cdot y.im}} \]
      4. pow2N/A

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

        \[\leadsto \frac{x.im \cdot y.re - x.re \cdot y.im}{\color{blue}{\mathsf{fma}\left(y.re, y.re, {y.im}^{2}\right)}} \]
      6. pow2N/A

        \[\leadsto \frac{x.im \cdot y.re - x.re \cdot y.im}{\mathsf{fma}\left(y.re, y.re, \color{blue}{y.im \cdot y.im}\right)} \]
      7. lift-*.f6476.9

        \[\leadsto \frac{x.im \cdot y.re - x.re \cdot y.im}{\mathsf{fma}\left(y.re, y.re, \color{blue}{y.im \cdot y.im}\right)} \]
    3. Applied rewrites76.9%

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

Alternative 3: 78.6% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{y.re}, \frac{x.im}{y.re}\right)\\ \mathbf{if}\;y.re \leq -1.65 \cdot 10^{+129}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y.re \leq 3 \cdot 10^{-6}:\\ \;\;\;\;\frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -x.re\right)}{y.im}\\ \mathbf{elif}\;y.re \leq 7.8 \cdot 10^{+99}:\\ \;\;\;\;x.im \cdot \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (let* ((t_0 (fma (/ (- x.re) y.re) (/ y.im y.re) (/ x.im y.re))))
   (if (<= y.re -1.65e+129)
     t_0
     (if (<= y.re 3e-6)
       (/ (fma x.im (/ y.re y.im) (- x.re)) y.im)
       (if (<= y.re 7.8e+99)
         (* x.im (/ y.re (fma y.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((-x_46_re / y_46_re), (y_46_im / y_46_re), (x_46_im / y_46_re));
	double tmp;
	if (y_46_re <= -1.65e+129) {
		tmp = t_0;
	} else if (y_46_re <= 3e-6) {
		tmp = fma(x_46_im, (y_46_re / y_46_im), -x_46_re) / y_46_im;
	} else if (y_46_re <= 7.8e+99) {
		tmp = x_46_im * (y_46_re / fma(y_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 = fma(Float64(Float64(-x_46_re) / y_46_re), Float64(y_46_im / y_46_re), Float64(x_46_im / y_46_re))
	tmp = 0.0
	if (y_46_re <= -1.65e+129)
		tmp = t_0;
	elseif (y_46_re <= 3e-6)
		tmp = Float64(fma(x_46_im, Float64(y_46_re / y_46_im), Float64(-x_46_re)) / y_46_im);
	elseif (y_46_re <= 7.8e+99)
		tmp = Float64(x_46_im * Float64(y_46_re / fma(y_46_im, y_46_im, Float64(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[((-x$46$re) / y$46$re), $MachinePrecision] * N[(y$46$im / y$46$re), $MachinePrecision] + N[(x$46$im / y$46$re), $MachinePrecision]), $MachinePrecision]}, If[LessEqual[y$46$re, -1.65e+129], t$95$0, If[LessEqual[y$46$re, 3e-6], N[(N[(x$46$im * N[(y$46$re / y$46$im), $MachinePrecision] + (-x$46$re)), $MachinePrecision] / y$46$im), $MachinePrecision], If[LessEqual[y$46$re, 7.8e+99], N[(x$46$im * N[(y$46$re / N[(y$46$im * y$46$im + N[(y$46$re * y$46$re), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$0]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{y.re}, \frac{x.im}{y.re}\right)\\
\mathbf{if}\;y.re \leq -1.65 \cdot 10^{+129}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y.re \leq 3 \cdot 10^{-6}:\\
\;\;\;\;\frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -x.re\right)}{y.im}\\

\mathbf{elif}\;y.re \leq 7.8 \cdot 10^{+99}:\\
\;\;\;\;x.im \cdot \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y.re < -1.64999999999999995e129 or 7.79999999999999989e99 < y.re

    1. Initial program 35.2%

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

      \[\leadsto \color{blue}{-1 \cdot \frac{x.re \cdot y.im}{{y.re}^{2}} + \frac{x.im}{y.re}} \]
    3. Step-by-step derivation
      1. associate-*r/N/A

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

        \[\leadsto \frac{\left(-1 \cdot x.re\right) \cdot y.im}{{y.re}^{2}} + \frac{x.im}{y.re} \]
      3. pow2N/A

        \[\leadsto \frac{\left(-1 \cdot x.re\right) \cdot y.im}{y.re \cdot y.re} + \frac{x.im}{y.re} \]
      4. times-fracN/A

        \[\leadsto \frac{-1 \cdot x.re}{y.re} \cdot \frac{y.im}{y.re} + \frac{\color{blue}{x.im}}{y.re} \]
      5. lower-fma.f64N/A

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{\color{blue}{y.re}}, \frac{x.im}{y.re}\right) \]
      10. lower-/.f6485.6

        \[\leadsto \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{y.re}, \frac{x.im}{y.re}\right) \]
    4. Applied rewrites85.6%

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

    if -1.64999999999999995e129 < y.re < 3.0000000000000001e-6

    1. Initial program 73.4%

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

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

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

        \[\leadsto \frac{\frac{x.im \cdot y.re}{y.im} + -1 \cdot x.re}{y.im} \]
      3. associate-/l*N/A

        \[\leadsto \frac{x.im \cdot \frac{y.re}{y.im} + -1 \cdot x.re}{y.im} \]
      4. lower-fma.f64N/A

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

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -1 \cdot x.re\right)}{y.im} \]
      6. mul-1-negN/A

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, \mathsf{neg}\left(x.re\right)\right)}{y.im} \]
      7. lower-neg.f6473.9

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -x.re\right)}{y.im} \]
    4. Applied rewrites73.9%

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

    if 3.0000000000000001e-6 < y.re < 7.79999999999999989e99

    1. Initial program 74.1%

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

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

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

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

        \[\leadsto x.im \cdot \frac{y.re}{\color{blue}{{y.im}^{2} + {y.re}^{2}}} \]
      4. pow2N/A

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

        \[\leadsto x.im \cdot \frac{y.re}{\mathsf{fma}\left(y.im, \color{blue}{y.im}, {y.re}^{2}\right)} \]
      6. pow2N/A

        \[\leadsto x.im \cdot \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)} \]
      7. lift-*.f6460.8

        \[\leadsto x.im \cdot \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)} \]
    4. Applied rewrites60.8%

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

Alternative 4: 76.4% accurate, 0.7× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\mathsf{fma}\left(-x.re, \frac{y.im}{y.re}, x.im\right)}{y.re}\\ \mathbf{if}\;y.re \leq -1.65 \cdot 10^{+129}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y.re \leq 3 \cdot 10^{-6}:\\ \;\;\;\;\frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -x.re\right)}{y.im}\\ \mathbf{elif}\;y.re \leq 7.8 \cdot 10^{+99}:\\ \;\;\;\;x.im \cdot \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (let* ((t_0 (/ (fma (- x.re) (/ y.im y.re) x.im) y.re)))
   (if (<= y.re -1.65e+129)
     t_0
     (if (<= y.re 3e-6)
       (/ (fma x.im (/ y.re y.im) (- x.re)) y.im)
       (if (<= y.re 7.8e+99)
         (* x.im (/ y.re (fma y.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(-x_46_re, (y_46_im / y_46_re), x_46_im) / y_46_re;
	double tmp;
	if (y_46_re <= -1.65e+129) {
		tmp = t_0;
	} else if (y_46_re <= 3e-6) {
		tmp = fma(x_46_im, (y_46_re / y_46_im), -x_46_re) / y_46_im;
	} else if (y_46_re <= 7.8e+99) {
		tmp = x_46_im * (y_46_re / fma(y_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(Float64(-x_46_re), Float64(y_46_im / y_46_re), x_46_im) / y_46_re)
	tmp = 0.0
	if (y_46_re <= -1.65e+129)
		tmp = t_0;
	elseif (y_46_re <= 3e-6)
		tmp = Float64(fma(x_46_im, Float64(y_46_re / y_46_im), Float64(-x_46_re)) / y_46_im);
	elseif (y_46_re <= 7.8e+99)
		tmp = Float64(x_46_im * Float64(y_46_re / fma(y_46_im, y_46_im, Float64(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[((-x$46$re) * N[(y$46$im / y$46$re), $MachinePrecision] + x$46$im), $MachinePrecision] / y$46$re), $MachinePrecision]}, If[LessEqual[y$46$re, -1.65e+129], t$95$0, If[LessEqual[y$46$re, 3e-6], N[(N[(x$46$im * N[(y$46$re / y$46$im), $MachinePrecision] + (-x$46$re)), $MachinePrecision] / y$46$im), $MachinePrecision], If[LessEqual[y$46$re, 7.8e+99], N[(x$46$im * N[(y$46$re / N[(y$46$im * y$46$im + N[(y$46$re * y$46$re), $MachinePrecision]), $MachinePrecision]), $MachinePrecision]), $MachinePrecision], t$95$0]]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\mathsf{fma}\left(-x.re, \frac{y.im}{y.re}, x.im\right)}{y.re}\\
\mathbf{if}\;y.re \leq -1.65 \cdot 10^{+129}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y.re \leq 3 \cdot 10^{-6}:\\
\;\;\;\;\frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -x.re\right)}{y.im}\\

\mathbf{elif}\;y.re \leq 7.8 \cdot 10^{+99}:\\
\;\;\;\;x.im \cdot \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 3 regimes
  2. if y.re < -1.64999999999999995e129 or 7.79999999999999989e99 < y.re

    1. Initial program 35.2%

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

      \[\leadsto \color{blue}{-1 \cdot \frac{x.re \cdot y.im}{{y.re}^{2}} + \frac{x.im}{y.re}} \]
    3. Step-by-step derivation
      1. associate-*r/N/A

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

        \[\leadsto \frac{\left(-1 \cdot x.re\right) \cdot y.im}{{y.re}^{2}} + \frac{x.im}{y.re} \]
      3. pow2N/A

        \[\leadsto \frac{\left(-1 \cdot x.re\right) \cdot y.im}{y.re \cdot y.re} + \frac{x.im}{y.re} \]
      4. times-fracN/A

        \[\leadsto \frac{-1 \cdot x.re}{y.re} \cdot \frac{y.im}{y.re} + \frac{\color{blue}{x.im}}{y.re} \]
      5. lower-fma.f64N/A

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{\color{blue}{y.re}}, \frac{x.im}{y.re}\right) \]
      10. lower-/.f6485.6

        \[\leadsto \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{y.re}, \frac{x.im}{y.re}\right) \]
    4. Applied rewrites85.6%

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

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

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

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

        \[\leadsto \frac{\mathsf{neg}\left(x.re\right)}{y.re} \cdot \frac{y.im}{y.re} + \frac{x.im}{y.re} \]
      5. lift-/.f64N/A

        \[\leadsto \frac{\mathsf{neg}\left(x.re\right)}{y.re} \cdot \frac{y.im}{y.re} + \frac{x.im}{y.re} \]
      6. associate-*l/N/A

        \[\leadsto \frac{\left(\mathsf{neg}\left(x.re\right)\right) \cdot \frac{y.im}{y.re}}{y.re} + \frac{\color{blue}{x.im}}{y.re} \]
      7. div-add-revN/A

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

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

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

        \[\leadsto \frac{\mathsf{fma}\left(-x.re, \frac{y.im}{y.re}, x.im\right)}{y.re} \]
      11. lift-/.f6485.0

        \[\leadsto \frac{\mathsf{fma}\left(-x.re, \frac{y.im}{y.re}, x.im\right)}{y.re} \]
    6. Applied rewrites85.0%

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

    if -1.64999999999999995e129 < y.re < 3.0000000000000001e-6

    1. Initial program 73.4%

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

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

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

        \[\leadsto \frac{\frac{x.im \cdot y.re}{y.im} + -1 \cdot x.re}{y.im} \]
      3. associate-/l*N/A

        \[\leadsto \frac{x.im \cdot \frac{y.re}{y.im} + -1 \cdot x.re}{y.im} \]
      4. lower-fma.f64N/A

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

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -1 \cdot x.re\right)}{y.im} \]
      6. mul-1-negN/A

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, \mathsf{neg}\left(x.re\right)\right)}{y.im} \]
      7. lower-neg.f6473.9

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -x.re\right)}{y.im} \]
    4. Applied rewrites73.9%

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

    if 3.0000000000000001e-6 < y.re < 7.79999999999999989e99

    1. Initial program 74.1%

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

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

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

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

        \[\leadsto x.im \cdot \frac{y.re}{\color{blue}{{y.im}^{2} + {y.re}^{2}}} \]
      4. pow2N/A

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

        \[\leadsto x.im \cdot \frac{y.re}{\mathsf{fma}\left(y.im, \color{blue}{y.im}, {y.re}^{2}\right)} \]
      6. pow2N/A

        \[\leadsto x.im \cdot \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)} \]
      7. lift-*.f6460.8

        \[\leadsto x.im \cdot \frac{y.re}{\mathsf{fma}\left(y.im, y.im, y.re \cdot y.re\right)} \]
    4. Applied rewrites60.8%

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

Alternative 5: 76.2% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\mathsf{fma}\left(-x.re, \frac{y.im}{y.re}, x.im\right)}{y.re}\\ \mathbf{if}\;y.re \leq -1.65 \cdot 10^{+129}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y.re \leq 230000000:\\ \;\;\;\;\frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -x.re\right)}{y.im}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (let* ((t_0 (/ (fma (- x.re) (/ y.im y.re) x.im) y.re)))
   (if (<= y.re -1.65e+129)
     t_0
     (if (<= y.re 230000000.0)
       (/ (fma x.im (/ y.re y.im) (- x.re)) 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_re, (y_46_im / y_46_re), x_46_im) / y_46_re;
	double tmp;
	if (y_46_re <= -1.65e+129) {
		tmp = t_0;
	} else if (y_46_re <= 230000000.0) {
		tmp = fma(x_46_im, (y_46_re / y_46_im), -x_46_re) / 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(Float64(-x_46_re), Float64(y_46_im / y_46_re), x_46_im) / y_46_re)
	tmp = 0.0
	if (y_46_re <= -1.65e+129)
		tmp = t_0;
	elseif (y_46_re <= 230000000.0)
		tmp = Float64(fma(x_46_im, Float64(y_46_re / y_46_im), Float64(-x_46_re)) / 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$46$re) * N[(y$46$im / y$46$re), $MachinePrecision] + x$46$im), $MachinePrecision] / y$46$re), $MachinePrecision]}, If[LessEqual[y$46$re, -1.65e+129], t$95$0, If[LessEqual[y$46$re, 230000000.0], N[(N[(x$46$im * N[(y$46$re / y$46$im), $MachinePrecision] + (-x$46$re)), $MachinePrecision] / y$46$im), $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\mathsf{fma}\left(-x.re, \frac{y.im}{y.re}, x.im\right)}{y.re}\\
\mathbf{if}\;y.re \leq -1.65 \cdot 10^{+129}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y.re \leq 230000000:\\
\;\;\;\;\frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -x.re\right)}{y.im}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y.re < -1.64999999999999995e129 or 2.3e8 < y.re

    1. Initial program 42.5%

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

      \[\leadsto \color{blue}{-1 \cdot \frac{x.re \cdot y.im}{{y.re}^{2}} + \frac{x.im}{y.re}} \]
    3. Step-by-step derivation
      1. associate-*r/N/A

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

        \[\leadsto \frac{\left(-1 \cdot x.re\right) \cdot y.im}{{y.re}^{2}} + \frac{x.im}{y.re} \]
      3. pow2N/A

        \[\leadsto \frac{\left(-1 \cdot x.re\right) \cdot y.im}{y.re \cdot y.re} + \frac{x.im}{y.re} \]
      4. times-fracN/A

        \[\leadsto \frac{-1 \cdot x.re}{y.re} \cdot \frac{y.im}{y.re} + \frac{\color{blue}{x.im}}{y.re} \]
      5. lower-fma.f64N/A

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

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

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

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

        \[\leadsto \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{\color{blue}{y.re}}, \frac{x.im}{y.re}\right) \]
      10. lower-/.f6481.2

        \[\leadsto \mathsf{fma}\left(\frac{-x.re}{y.re}, \frac{y.im}{y.re}, \frac{x.im}{y.re}\right) \]
    4. Applied rewrites81.2%

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

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

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

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

        \[\leadsto \frac{\mathsf{neg}\left(x.re\right)}{y.re} \cdot \frac{y.im}{y.re} + \frac{x.im}{y.re} \]
      5. lift-/.f64N/A

        \[\leadsto \frac{\mathsf{neg}\left(x.re\right)}{y.re} \cdot \frac{y.im}{y.re} + \frac{x.im}{y.re} \]
      6. associate-*l/N/A

        \[\leadsto \frac{\left(\mathsf{neg}\left(x.re\right)\right) \cdot \frac{y.im}{y.re}}{y.re} + \frac{\color{blue}{x.im}}{y.re} \]
      7. div-add-revN/A

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

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

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

        \[\leadsto \frac{\mathsf{fma}\left(-x.re, \frac{y.im}{y.re}, x.im\right)}{y.re} \]
      11. lift-/.f6480.6

        \[\leadsto \frac{\mathsf{fma}\left(-x.re, \frac{y.im}{y.re}, x.im\right)}{y.re} \]
    6. Applied rewrites80.6%

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

    if -1.64999999999999995e129 < y.re < 2.3e8

    1. Initial program 73.5%

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

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

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

        \[\leadsto \frac{\frac{x.im \cdot y.re}{y.im} + -1 \cdot x.re}{y.im} \]
      3. associate-/l*N/A

        \[\leadsto \frac{x.im \cdot \frac{y.re}{y.im} + -1 \cdot x.re}{y.im} \]
      4. lower-fma.f64N/A

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

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -1 \cdot x.re\right)}{y.im} \]
      6. mul-1-negN/A

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, \mathsf{neg}\left(x.re\right)\right)}{y.im} \]
      7. lower-neg.f6473.4

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -x.re\right)}{y.im} \]
    4. Applied rewrites73.4%

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

Alternative 6: 76.2% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -x.re\right)}{y.im}\\ \mathbf{if}\;y.im \leq -1.35 \cdot 10^{-10}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y.im \leq 4 \cdot 10^{-24}:\\ \;\;\;\;\frac{x.im - \frac{y.im \cdot x.re}{y.re}}{y.re}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (let* ((t_0 (/ (fma x.im (/ y.re y.im) (- x.re)) y.im)))
   (if (<= y.im -1.35e-10)
     t_0
     (if (<= y.im 4e-24) (/ (- x.im (/ (* y.im x.re) 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(x_46_im, (y_46_re / y_46_im), -x_46_re) / y_46_im;
	double tmp;
	if (y_46_im <= -1.35e-10) {
		tmp = t_0;
	} else if (y_46_im <= 4e-24) {
		tmp = (x_46_im - ((y_46_im * x_46_re) / 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(x_46_im, Float64(y_46_re / y_46_im), Float64(-x_46_re)) / y_46_im)
	tmp = 0.0
	if (y_46_im <= -1.35e-10)
		tmp = t_0;
	elseif (y_46_im <= 4e-24)
		tmp = Float64(Float64(x_46_im - Float64(Float64(y_46_im * x_46_re) / 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[(x$46$im * N[(y$46$re / y$46$im), $MachinePrecision] + (-x$46$re)), $MachinePrecision] / y$46$im), $MachinePrecision]}, If[LessEqual[y$46$im, -1.35e-10], t$95$0, If[LessEqual[y$46$im, 4e-24], N[(N[(x$46$im - N[(N[(y$46$im * x$46$re), $MachinePrecision] / y$46$re), $MachinePrecision]), $MachinePrecision] / y$46$re), $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -x.re\right)}{y.im}\\
\mathbf{if}\;y.im \leq -1.35 \cdot 10^{-10}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y.im \leq 4 \cdot 10^{-24}:\\
\;\;\;\;\frac{x.im - \frac{y.im \cdot x.re}{y.re}}{y.re}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y.im < -1.35e-10 or 3.99999999999999969e-24 < y.im

    1. Initial program 50.0%

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

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

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

        \[\leadsto \frac{\frac{x.im \cdot y.re}{y.im} + -1 \cdot x.re}{y.im} \]
      3. associate-/l*N/A

        \[\leadsto \frac{x.im \cdot \frac{y.re}{y.im} + -1 \cdot x.re}{y.im} \]
      4. lower-fma.f64N/A

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

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -1 \cdot x.re\right)}{y.im} \]
      6. mul-1-negN/A

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, \mathsf{neg}\left(x.re\right)\right)}{y.im} \]
      7. lower-neg.f6474.7

        \[\leadsto \frac{\mathsf{fma}\left(x.im, \frac{y.re}{y.im}, -x.re\right)}{y.im} \]
    4. Applied rewrites74.7%

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

    if -1.35e-10 < y.im < 3.99999999999999969e-24

    1. Initial program 74.0%

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

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

        \[\leadsto \frac{x.im + -1 \cdot \frac{x.re \cdot y.im}{y.re}}{\color{blue}{y.re}} \]
      2. fp-cancel-sign-sub-invN/A

        \[\leadsto \frac{x.im - \left(\mathsf{neg}\left(-1\right)\right) \cdot \frac{x.re \cdot y.im}{y.re}}{y.re} \]
      3. metadata-evalN/A

        \[\leadsto \frac{x.im - 1 \cdot \frac{x.re \cdot y.im}{y.re}}{y.re} \]
      4. metadata-evalN/A

        \[\leadsto \frac{x.im - \frac{-1}{-1} \cdot \frac{x.re \cdot y.im}{y.re}}{y.re} \]
      5. times-fracN/A

        \[\leadsto \frac{x.im - \frac{-1 \cdot \left(x.re \cdot y.im\right)}{-1 \cdot y.re}}{y.re} \]
      6. mul-1-negN/A

        \[\leadsto \frac{x.im - \frac{\mathsf{neg}\left(x.re \cdot y.im\right)}{-1 \cdot y.re}}{y.re} \]
      7. mul-1-negN/A

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

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

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

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

        \[\leadsto \frac{x.im - \frac{y.im \cdot x.re}{y.re}}{y.re} \]
      12. lower-*.f6482.8

        \[\leadsto \frac{x.im - \frac{y.im \cdot x.re}{y.re}}{y.re} \]
    4. Applied rewrites82.8%

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

Alternative 7: 73.0% accurate, 0.9× speedup?

\[\begin{array}{l} \\ \begin{array}{l} t_0 := \frac{-x.re}{y.im}\\ \mathbf{if}\;y.im \leq -2.9 \cdot 10^{-10}:\\ \;\;\;\;t\_0\\ \mathbf{elif}\;y.im \leq 4.9 \cdot 10^{+76}:\\ \;\;\;\;\frac{x.im - \frac{y.im \cdot x.re}{y.re}}{y.re}\\ \mathbf{else}:\\ \;\;\;\;t\_0\\ \end{array} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (let* ((t_0 (/ (- x.re) y.im)))
   (if (<= y.im -2.9e-10)
     t_0
     (if (<= y.im 4.9e+76) (/ (- x.im (/ (* y.im x.re) 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 = -x_46_re / y_46_im;
	double tmp;
	if (y_46_im <= -2.9e-10) {
		tmp = t_0;
	} else if (y_46_im <= 4.9e+76) {
		tmp = (x_46_im - ((y_46_im * x_46_re) / y_46_re)) / y_46_re;
	} else {
		tmp = t_0;
	}
	return tmp;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

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) :: t_0
    real(8) :: tmp
    t_0 = -x_46re / y_46im
    if (y_46im <= (-2.9d-10)) then
        tmp = t_0
    else if (y_46im <= 4.9d+76) then
        tmp = (x_46im - ((y_46im * x_46re) / y_46re)) / y_46re
    else
        tmp = t_0
    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 t_0 = -x_46_re / y_46_im;
	double tmp;
	if (y_46_im <= -2.9e-10) {
		tmp = t_0;
	} else if (y_46_im <= 4.9e+76) {
		tmp = (x_46_im - ((y_46_im * x_46_re) / y_46_re)) / y_46_re;
	} else {
		tmp = t_0;
	}
	return tmp;
}
def code(x_46_re, x_46_im, y_46_re, y_46_im):
	t_0 = -x_46_re / y_46_im
	tmp = 0
	if y_46_im <= -2.9e-10:
		tmp = t_0
	elif y_46_im <= 4.9e+76:
		tmp = (x_46_im - ((y_46_im * x_46_re) / 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(Float64(-x_46_re) / y_46_im)
	tmp = 0.0
	if (y_46_im <= -2.9e-10)
		tmp = t_0;
	elseif (y_46_im <= 4.9e+76)
		tmp = Float64(Float64(x_46_im - Float64(Float64(y_46_im * x_46_re) / y_46_re)) / y_46_re);
	else
		tmp = t_0;
	end
	return tmp
end
function tmp_2 = code(x_46_re, x_46_im, y_46_re, y_46_im)
	t_0 = -x_46_re / y_46_im;
	tmp = 0.0;
	if (y_46_im <= -2.9e-10)
		tmp = t_0;
	elseif (y_46_im <= 4.9e+76)
		tmp = (x_46_im - ((y_46_im * x_46_re) / y_46_re)) / y_46_re;
	else
		tmp = t_0;
	end
	tmp_2 = tmp;
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := Block[{t$95$0 = N[((-x$46$re) / y$46$im), $MachinePrecision]}, If[LessEqual[y$46$im, -2.9e-10], t$95$0, If[LessEqual[y$46$im, 4.9e+76], N[(N[(x$46$im - N[(N[(y$46$im * x$46$re), $MachinePrecision] / y$46$re), $MachinePrecision]), $MachinePrecision] / y$46$re), $MachinePrecision], t$95$0]]]
\begin{array}{l}

\\
\begin{array}{l}
t_0 := \frac{-x.re}{y.im}\\
\mathbf{if}\;y.im \leq -2.9 \cdot 10^{-10}:\\
\;\;\;\;t\_0\\

\mathbf{elif}\;y.im \leq 4.9 \cdot 10^{+76}:\\
\;\;\;\;\frac{x.im - \frac{y.im \cdot x.re}{y.re}}{y.re}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y.im < -2.89999999999999981e-10 or 4.90000000000000026e76 < y.im

    1. Initial program 45.3%

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

      \[\leadsto \color{blue}{-1 \cdot \frac{x.re}{y.im}} \]
    3. Step-by-step derivation
      1. associate-*r/N/A

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

        \[\leadsto \frac{-1 \cdot x.re}{\color{blue}{y.im}} \]
      3. mul-1-negN/A

        \[\leadsto \frac{\mathsf{neg}\left(x.re\right)}{y.im} \]
      4. lower-neg.f6467.0

        \[\leadsto \frac{-x.re}{y.im} \]
    4. Applied rewrites67.0%

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

    if -2.89999999999999981e-10 < y.im < 4.90000000000000026e76

    1. Initial program 74.3%

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

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

        \[\leadsto \frac{x.im + -1 \cdot \frac{x.re \cdot y.im}{y.re}}{\color{blue}{y.re}} \]
      2. fp-cancel-sign-sub-invN/A

        \[\leadsto \frac{x.im - \left(\mathsf{neg}\left(-1\right)\right) \cdot \frac{x.re \cdot y.im}{y.re}}{y.re} \]
      3. metadata-evalN/A

        \[\leadsto \frac{x.im - 1 \cdot \frac{x.re \cdot y.im}{y.re}}{y.re} \]
      4. metadata-evalN/A

        \[\leadsto \frac{x.im - \frac{-1}{-1} \cdot \frac{x.re \cdot y.im}{y.re}}{y.re} \]
      5. times-fracN/A

        \[\leadsto \frac{x.im - \frac{-1 \cdot \left(x.re \cdot y.im\right)}{-1 \cdot y.re}}{y.re} \]
      6. mul-1-negN/A

        \[\leadsto \frac{x.im - \frac{\mathsf{neg}\left(x.re \cdot y.im\right)}{-1 \cdot y.re}}{y.re} \]
      7. mul-1-negN/A

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

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

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

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

        \[\leadsto \frac{x.im - \frac{y.im \cdot x.re}{y.re}}{y.re} \]
      12. lower-*.f6477.7

        \[\leadsto \frac{x.im - \frac{y.im \cdot x.re}{y.re}}{y.re} \]
    4. Applied rewrites77.7%

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

Alternative 8: 64.2% accurate, 1.3× speedup?

\[\begin{array}{l} \\ \begin{array}{l} \mathbf{if}\;y.re \leq -1.72 \cdot 10^{+61}:\\ \;\;\;\;\frac{x.im}{y.re}\\ \mathbf{elif}\;y.re \leq 2.8 \cdot 10^{-33}:\\ \;\;\;\;\frac{-x.re}{y.im}\\ \mathbf{else}:\\ \;\;\;\;\frac{x.im}{y.re}\\ \end{array} \end{array} \]
(FPCore (x.re x.im y.re y.im)
 :precision binary64
 (if (<= y.re -1.72e+61)
   (/ x.im y.re)
   (if (<= y.re 2.8e-33) (/ (- x.re) y.im) (/ x.im 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 <= -1.72e+61) {
		tmp = x_46_im / y_46_re;
	} else if (y_46_re <= 2.8e-33) {
		tmp = -x_46_re / y_46_im;
	} else {
		tmp = x_46_im / y_46_re;
	}
	return tmp;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

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_46re <= (-1.72d+61)) then
        tmp = x_46im / y_46re
    else if (y_46re <= 2.8d-33) then
        tmp = -x_46re / y_46im
    else
        tmp = x_46im / 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 <= -1.72e+61) {
		tmp = x_46_im / y_46_re;
	} else if (y_46_re <= 2.8e-33) {
		tmp = -x_46_re / y_46_im;
	} else {
		tmp = x_46_im / 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 <= -1.72e+61:
		tmp = x_46_im / y_46_re
	elif y_46_re <= 2.8e-33:
		tmp = -x_46_re / y_46_im
	else:
		tmp = x_46_im / 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 <= -1.72e+61)
		tmp = Float64(x_46_im / y_46_re);
	elseif (y_46_re <= 2.8e-33)
		tmp = Float64(Float64(-x_46_re) / y_46_im);
	else
		tmp = Float64(x_46_im / 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 <= -1.72e+61)
		tmp = x_46_im / y_46_re;
	elseif (y_46_re <= 2.8e-33)
		tmp = -x_46_re / y_46_im;
	else
		tmp = x_46_im / 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, -1.72e+61], N[(x$46$im / y$46$re), $MachinePrecision], If[LessEqual[y$46$re, 2.8e-33], N[((-x$46$re) / y$46$im), $MachinePrecision], N[(x$46$im / y$46$re), $MachinePrecision]]]
\begin{array}{l}

\\
\begin{array}{l}
\mathbf{if}\;y.re \leq -1.72 \cdot 10^{+61}:\\
\;\;\;\;\frac{x.im}{y.re}\\

\mathbf{elif}\;y.re \leq 2.8 \cdot 10^{-33}:\\
\;\;\;\;\frac{-x.re}{y.im}\\

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


\end{array}
\end{array}
Derivation
  1. Split input into 2 regimes
  2. if y.re < -1.71999999999999988e61 or 2.8e-33 < y.re

    1. Initial program 48.2%

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

      \[\leadsto \color{blue}{\frac{x.im}{y.re}} \]
    3. Step-by-step derivation
      1. lower-/.f6466.0

        \[\leadsto \frac{x.im}{\color{blue}{y.re}} \]
    4. Applied rewrites66.0%

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

    if -1.71999999999999988e61 < y.re < 2.8e-33

    1. Initial program 73.7%

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

      \[\leadsto \color{blue}{-1 \cdot \frac{x.re}{y.im}} \]
    3. Step-by-step derivation
      1. associate-*r/N/A

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

        \[\leadsto \frac{-1 \cdot x.re}{\color{blue}{y.im}} \]
      3. mul-1-negN/A

        \[\leadsto \frac{\mathsf{neg}\left(x.re\right)}{y.im} \]
      4. lower-neg.f6462.5

        \[\leadsto \frac{-x.re}{y.im} \]
    4. Applied rewrites62.5%

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

Alternative 9: 43.4% accurate, 5.0× speedup?

\[\begin{array}{l} \\ \frac{x.im}{y.re} \end{array} \]
(FPCore (x.re x.im y.re y.im) :precision binary64 (/ x.im y.re))
double code(double x_46_re, double x_46_im, double y_46_re, double y_46_im) {
	return x_46_im / y_46_re;
}
module fmin_fmax_functions
    implicit none
    private
    public fmax
    public fmin

    interface fmax
        module procedure fmax88
        module procedure fmax44
        module procedure fmax84
        module procedure fmax48
    end interface
    interface fmin
        module procedure fmin88
        module procedure fmin44
        module procedure fmin84
        module procedure fmin48
    end interface
contains
    real(8) function fmax88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(4) function fmax44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, max(x, y), y /= y), x /= x)
    end function
    real(8) function fmax84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, max(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmax48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), max(dble(x), y), y /= y), x /= x)
    end function
    real(8) function fmin88(x, y) result (res)
        real(8), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(4) function fmin44(x, y) result (res)
        real(4), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(y, merge(x, min(x, y), y /= y), x /= x)
    end function
    real(8) function fmin84(x, y) result(res)
        real(8), intent (in) :: x
        real(4), intent (in) :: y
        res = merge(dble(y), merge(x, min(x, dble(y)), y /= y), x /= x)
    end function
    real(8) function fmin48(x, y) result(res)
        real(4), intent (in) :: x
        real(8), intent (in) :: y
        res = merge(y, merge(dble(x), min(dble(x), y), y /= y), x /= x)
    end function
end module

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_46re
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_re;
}
def code(x_46_re, x_46_im, y_46_re, y_46_im):
	return x_46_im / y_46_re
function code(x_46_re, x_46_im, y_46_re, y_46_im)
	return Float64(x_46_im / y_46_re)
end
function tmp = code(x_46_re, x_46_im, y_46_re, y_46_im)
	tmp = x_46_im / y_46_re;
end
code[x$46$re_, x$46$im_, y$46$re_, y$46$im_] := N[(x$46$im / y$46$re), $MachinePrecision]
\begin{array}{l}

\\
\frac{x.im}{y.re}
\end{array}
Derivation
  1. Initial program 61.6%

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

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

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

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

Reproduce

?
herbie shell --seed 2025101 
(FPCore (x.re x.im y.re y.im)
  :name "_divideComplex, imaginary part"
  :precision binary64
  (/ (- (* x.im y.re) (* x.re y.im)) (+ (* y.re y.re) (* y.im y.im))))