0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} - re\right)}\begin{array}{l}
\mathbf{if}\;re \le -6.75406070697555614550103171070689226775 \cdot 10^{99}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(-2 \cdot re\right)}\\
\mathbf{elif}\;re \le -6.851668065765393813815957926512377199889 \cdot 10^{-264}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(\sqrt{\sqrt{re \cdot re + im \cdot im}} \cdot \sqrt{\sqrt{re \cdot re + im \cdot im}} - re\right)}\\
\mathbf{elif}\;re \le 2.821269380473622723862824940269700262969 \cdot 10^{-218}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(im - re\right)}\\
\mathbf{else}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \frac{{im}^{2}}{\sqrt{re \cdot re + im \cdot im} + re}}\\
\end{array}double f(double re, double im) {
double r17942 = 0.5;
double r17943 = 2.0;
double r17944 = re;
double r17945 = r17944 * r17944;
double r17946 = im;
double r17947 = r17946 * r17946;
double r17948 = r17945 + r17947;
double r17949 = sqrt(r17948);
double r17950 = r17949 - r17944;
double r17951 = r17943 * r17950;
double r17952 = sqrt(r17951);
double r17953 = r17942 * r17952;
return r17953;
}
double f(double re, double im) {
double r17954 = re;
double r17955 = -6.754060706975556e+99;
bool r17956 = r17954 <= r17955;
double r17957 = 0.5;
double r17958 = 2.0;
double r17959 = -2.0;
double r17960 = r17959 * r17954;
double r17961 = r17958 * r17960;
double r17962 = sqrt(r17961);
double r17963 = r17957 * r17962;
double r17964 = -6.851668065765394e-264;
bool r17965 = r17954 <= r17964;
double r17966 = r17954 * r17954;
double r17967 = im;
double r17968 = r17967 * r17967;
double r17969 = r17966 + r17968;
double r17970 = sqrt(r17969);
double r17971 = sqrt(r17970);
double r17972 = r17971 * r17971;
double r17973 = r17972 - r17954;
double r17974 = r17958 * r17973;
double r17975 = sqrt(r17974);
double r17976 = r17957 * r17975;
double r17977 = 2.8212693804736227e-218;
bool r17978 = r17954 <= r17977;
double r17979 = r17967 - r17954;
double r17980 = r17958 * r17979;
double r17981 = sqrt(r17980);
double r17982 = r17957 * r17981;
double r17983 = 2.0;
double r17984 = pow(r17967, r17983);
double r17985 = r17970 + r17954;
double r17986 = r17984 / r17985;
double r17987 = r17958 * r17986;
double r17988 = sqrt(r17987);
double r17989 = r17957 * r17988;
double r17990 = r17978 ? r17982 : r17989;
double r17991 = r17965 ? r17976 : r17990;
double r17992 = r17956 ? r17963 : r17991;
return r17992;
}



Bits error versus re



Bits error versus im
Results
if re < -6.754060706975556e+99Initial program 50.7
Taylor expanded around -inf 10.3
if -6.754060706975556e+99 < re < -6.851668065765394e-264Initial program 19.1
rmApplied add-sqr-sqrt19.1
Applied sqrt-prod19.2
if -6.851668065765394e-264 < re < 2.8212693804736227e-218Initial program 31.4
Taylor expanded around 0 33.8
if 2.8212693804736227e-218 < re Initial program 49.2
rmApplied flip--49.1
Simplified37.2
Final simplification27.1
herbie shell --seed 2019353
(FPCore (re im)
:name "math.sqrt on complex, imaginary part, im greater than 0 branch"
:precision binary64
(* 0.5 (sqrt (* 2 (- (sqrt (+ (* re re) (* im im))) re)))))