0.5 \cdot \sqrt{2.0 \cdot \left(\sqrt{re \cdot re + im \cdot im} - re\right)}\begin{array}{l}
\mathbf{if}\;re \le -4.865476810721751 \cdot 10^{+152}:\\
\;\;\;\;\sqrt{\left(-2 \cdot re\right) \cdot 2.0} \cdot 0.5\\
\mathbf{elif}\;re \le -7.2120676567993205 \cdot 10^{-304}:\\
\;\;\;\;\sqrt{2.0 \cdot \left(\sqrt{\sqrt{im \cdot im + re \cdot re}} \cdot \sqrt{\sqrt{im \cdot im + re \cdot re}} - re\right)} \cdot 0.5\\
\mathbf{else}:\\
\;\;\;\;\sqrt{2.0 \cdot \frac{im \cdot im}{\sqrt{im \cdot im + re \cdot re} + re}} \cdot 0.5\\
\end{array}double f(double re, double im) {
double r910240 = 0.5;
double r910241 = 2.0;
double r910242 = re;
double r910243 = r910242 * r910242;
double r910244 = im;
double r910245 = r910244 * r910244;
double r910246 = r910243 + r910245;
double r910247 = sqrt(r910246);
double r910248 = r910247 - r910242;
double r910249 = r910241 * r910248;
double r910250 = sqrt(r910249);
double r910251 = r910240 * r910250;
return r910251;
}
double f(double re, double im) {
double r910252 = re;
double r910253 = -4.865476810721751e+152;
bool r910254 = r910252 <= r910253;
double r910255 = -2.0;
double r910256 = r910255 * r910252;
double r910257 = 2.0;
double r910258 = r910256 * r910257;
double r910259 = sqrt(r910258);
double r910260 = 0.5;
double r910261 = r910259 * r910260;
double r910262 = -7.2120676567993205e-304;
bool r910263 = r910252 <= r910262;
double r910264 = im;
double r910265 = r910264 * r910264;
double r910266 = r910252 * r910252;
double r910267 = r910265 + r910266;
double r910268 = sqrt(r910267);
double r910269 = sqrt(r910268);
double r910270 = r910269 * r910269;
double r910271 = r910270 - r910252;
double r910272 = r910257 * r910271;
double r910273 = sqrt(r910272);
double r910274 = r910273 * r910260;
double r910275 = r910268 + r910252;
double r910276 = r910265 / r910275;
double r910277 = r910257 * r910276;
double r910278 = sqrt(r910277);
double r910279 = r910278 * r910260;
double r910280 = r910263 ? r910274 : r910279;
double r910281 = r910254 ? r910261 : r910280;
return r910281;
}



Bits error versus re



Bits error versus im
Results
if re < -4.865476810721751e+152Initial program 60.8
rmApplied add-sqr-sqrt60.8
Applied sqrt-prod60.8
rmApplied *-commutative60.8
Taylor expanded around -inf 8.0
if -4.865476810721751e+152 < re < -7.2120676567993205e-304Initial program 20.1
rmApplied add-sqr-sqrt20.1
Applied sqrt-prod20.2
rmApplied *-commutative20.2
if -7.2120676567993205e-304 < re Initial program 45.1
rmApplied add-sqr-sqrt45.1
Applied sqrt-prod45.5
rmApplied flip--45.5
Simplified35.3
Simplified35.2
Final simplification26.3
herbie shell --seed 2019129
(FPCore (re im)
:name "math.sqrt on complex, imaginary part, im greater than 0 branch"
(* 0.5 (sqrt (* 2.0 (- (sqrt (+ (* re re) (* im im))) re)))))