\frac{x.im \cdot y.re - x.re \cdot y.im}{y.re \cdot y.re + y.im \cdot y.im}\begin{array}{l}
\mathbf{if}\;y.im \le 7.672387965946080977078573905755541784636 \cdot 10^{87}:\\
\;\;\;\;\frac{\frac{x.im \cdot y.re - y.im \cdot x.re}{\sqrt{y.im \cdot y.im + y.re \cdot y.re}}}{\sqrt{y.im \cdot y.im + y.re \cdot y.re}}\\
\mathbf{else}:\\
\;\;\;\;\frac{-x.re}{\sqrt{y.im \cdot y.im + y.re \cdot y.re}}\\
\end{array}double f(double x_re, double x_im, double y_re, double y_im) {
double r5032984 = x_im;
double r5032985 = y_re;
double r5032986 = r5032984 * r5032985;
double r5032987 = x_re;
double r5032988 = y_im;
double r5032989 = r5032987 * r5032988;
double r5032990 = r5032986 - r5032989;
double r5032991 = r5032985 * r5032985;
double r5032992 = r5032988 * r5032988;
double r5032993 = r5032991 + r5032992;
double r5032994 = r5032990 / r5032993;
return r5032994;
}
double f(double x_re, double x_im, double y_re, double y_im) {
double r5032995 = y_im;
double r5032996 = 7.672387965946081e+87;
bool r5032997 = r5032995 <= r5032996;
double r5032998 = x_im;
double r5032999 = y_re;
double r5033000 = r5032998 * r5032999;
double r5033001 = x_re;
double r5033002 = r5032995 * r5033001;
double r5033003 = r5033000 - r5033002;
double r5033004 = r5032995 * r5032995;
double r5033005 = r5032999 * r5032999;
double r5033006 = r5033004 + r5033005;
double r5033007 = sqrt(r5033006);
double r5033008 = r5033003 / r5033007;
double r5033009 = r5033008 / r5033007;
double r5033010 = -r5033001;
double r5033011 = r5033010 / r5033007;
double r5033012 = r5032997 ? r5033009 : r5033011;
return r5033012;
}



Bits error versus x.re



Bits error versus x.im



Bits error versus y.re



Bits error versus y.im
Results
if y.im < 7.672387965946081e+87Initial program 23.1
rmApplied add-sqr-sqrt23.1
Applied associate-/r*23.0
if 7.672387965946081e+87 < y.im Initial program 38.8
rmApplied add-sqr-sqrt38.8
Applied associate-/r*38.8
Taylor expanded around 0 38.2
Simplified38.2
Final simplification26.0
herbie shell --seed 2019168
(FPCore (x.re x.im y.re y.im)
:name "_divideComplex, imaginary part"
(/ (- (* x.im y.re) (* x.re y.im)) (+ (* y.re y.re) (* y.im y.im))))