0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} - re\right)}\begin{array}{l}
\mathbf{if}\;re \le -8.615973159790100816135112956922113830758 \cdot 10^{-204}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(-2 \cdot re\right)}\\
\mathbf{elif}\;re \le 2.88234410399163811959624616338485820472 \cdot 10^{143}:\\
\;\;\;\;0.5 \cdot \frac{\left|im\right| \cdot \sqrt{2}}{\sqrt{\sqrt{re \cdot re + im \cdot im} + re}}\\
\mathbf{else}:\\
\;\;\;\;0.5 \cdot \left(\sqrt{2} \cdot \frac{\left|im\right|}{\sqrt{re + re}}\right)\\
\end{array}double f(double re, double im) {
double r25886 = 0.5;
double r25887 = 2.0;
double r25888 = re;
double r25889 = r25888 * r25888;
double r25890 = im;
double r25891 = r25890 * r25890;
double r25892 = r25889 + r25891;
double r25893 = sqrt(r25892);
double r25894 = r25893 - r25888;
double r25895 = r25887 * r25894;
double r25896 = sqrt(r25895);
double r25897 = r25886 * r25896;
return r25897;
}
double f(double re, double im) {
double r25898 = re;
double r25899 = -8.615973159790101e-204;
bool r25900 = r25898 <= r25899;
double r25901 = 0.5;
double r25902 = 2.0;
double r25903 = -2.0;
double r25904 = r25903 * r25898;
double r25905 = r25902 * r25904;
double r25906 = sqrt(r25905);
double r25907 = r25901 * r25906;
double r25908 = 2.882344103991638e+143;
bool r25909 = r25898 <= r25908;
double r25910 = im;
double r25911 = fabs(r25910);
double r25912 = sqrt(r25902);
double r25913 = r25911 * r25912;
double r25914 = r25898 * r25898;
double r25915 = r25910 * r25910;
double r25916 = r25914 + r25915;
double r25917 = sqrt(r25916);
double r25918 = r25917 + r25898;
double r25919 = sqrt(r25918);
double r25920 = r25913 / r25919;
double r25921 = r25901 * r25920;
double r25922 = r25898 + r25898;
double r25923 = sqrt(r25922);
double r25924 = r25911 / r25923;
double r25925 = r25912 * r25924;
double r25926 = r25901 * r25925;
double r25927 = r25909 ? r25921 : r25926;
double r25928 = r25900 ? r25907 : r25927;
return r25928;
}



Bits error versus re



Bits error versus im
Results
if re < -8.615973159790101e-204Initial program 31.9
Taylor expanded around -inf 25.2
if -8.615973159790101e-204 < re < 2.882344103991638e+143Initial program 37.5
rmApplied flip--37.6
Applied associate-*r/37.6
Applied sqrt-div37.9
Simplified29.5
rmApplied *-un-lft-identity29.5
Applied sqrt-prod29.5
Applied sqrt-prod29.6
Applied times-frac29.6
Simplified29.6
Simplified22.4
rmApplied associate-*r/22.4
Simplified22.4
if 2.882344103991638e+143 < re Initial program 63.1
rmApplied flip--63.1
Applied associate-*r/63.1
Applied sqrt-div63.1
Simplified49.3
rmApplied *-un-lft-identity49.3
Applied sqrt-prod49.3
Applied sqrt-prod49.3
Applied times-frac49.3
Simplified49.3
Simplified48.2
Taylor expanded around inf 9.0
Final simplification21.8
herbie shell --seed 2019323
(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)))))