0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} - re\right)}\begin{array}{l}
\mathbf{if}\;re \le -1.940119593462783780503740532731557409155 \cdot 10^{70}:\\
\;\;\;\;\sqrt{\left(-2 \cdot re\right) \cdot 2} \cdot 0.5\\
\mathbf{elif}\;re \le 2.170454861417431561301436996642453156775 \cdot 10^{-276}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(\sqrt{im \cdot im + re \cdot re} - re\right)}\\
\mathbf{else}:\\
\;\;\;\;0.5 \cdot \frac{\sqrt{2 \cdot \left(im \cdot im\right)}}{\sqrt{\sqrt{im \cdot im + re \cdot re} + re}}\\
\end{array}double f(double re, double im) {
double r921948 = 0.5;
double r921949 = 2.0;
double r921950 = re;
double r921951 = r921950 * r921950;
double r921952 = im;
double r921953 = r921952 * r921952;
double r921954 = r921951 + r921953;
double r921955 = sqrt(r921954);
double r921956 = r921955 - r921950;
double r921957 = r921949 * r921956;
double r921958 = sqrt(r921957);
double r921959 = r921948 * r921958;
return r921959;
}
double f(double re, double im) {
double r921960 = re;
double r921961 = -1.9401195934627838e+70;
bool r921962 = r921960 <= r921961;
double r921963 = -2.0;
double r921964 = r921963 * r921960;
double r921965 = 2.0;
double r921966 = r921964 * r921965;
double r921967 = sqrt(r921966);
double r921968 = 0.5;
double r921969 = r921967 * r921968;
double r921970 = 2.1704548614174316e-276;
bool r921971 = r921960 <= r921970;
double r921972 = im;
double r921973 = r921972 * r921972;
double r921974 = r921960 * r921960;
double r921975 = r921973 + r921974;
double r921976 = sqrt(r921975);
double r921977 = r921976 - r921960;
double r921978 = r921965 * r921977;
double r921979 = sqrt(r921978);
double r921980 = r921968 * r921979;
double r921981 = r921965 * r921973;
double r921982 = sqrt(r921981);
double r921983 = r921976 + r921960;
double r921984 = sqrt(r921983);
double r921985 = r921982 / r921984;
double r921986 = r921968 * r921985;
double r921987 = r921971 ? r921980 : r921986;
double r921988 = r921962 ? r921969 : r921987;
return r921988;
}



Bits error versus re



Bits error versus im
Results
if re < -1.9401195934627838e+70Initial program 46.3
Taylor expanded around -inf 12.0
if -1.9401195934627838e+70 < re < 2.1704548614174316e-276Initial program 22.3
if 2.1704548614174316e-276 < re Initial program 47.2
rmApplied add-exp-log49.4
rmApplied flip--49.2
Applied associate-*r/49.2
Applied sqrt-div49.2
Simplified36.5
Simplified35.3
Final simplification26.3
herbie shell --seed 2019179
(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)))))