0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} - re\right)}\begin{array}{l}
\mathbf{if}\;re \le -2.797060425996081289789292529027987197048 \cdot 10^{81}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(-2 \cdot re\right)}\\
\mathbf{elif}\;re \le -1.796065771880538982336997204574724695612 \cdot 10^{-203}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(\sqrt{\sqrt{\sqrt{re \cdot re + im \cdot im}}} \cdot \left({\left(\sqrt{\sqrt{\sqrt{re \cdot re + im \cdot im}}}\right)}^{\left(\frac{3}{2}\right)} \cdot {\left(\sqrt{\sqrt{\sqrt{re \cdot re + im \cdot im}}}\right)}^{\left(\frac{3}{2}\right)}\right) - re\right)}\\
\mathbf{elif}\;re \le 7.84333861213225274022933802875203231721 \cdot 10^{-202}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(im - re\right)}\\
\mathbf{else}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \frac{{im}^{2}}{re + \sqrt{re \cdot re + im \cdot im}}}\\
\end{array}double f(double re, double im) {
double r23061 = 0.5;
double r23062 = 2.0;
double r23063 = re;
double r23064 = r23063 * r23063;
double r23065 = im;
double r23066 = r23065 * r23065;
double r23067 = r23064 + r23066;
double r23068 = sqrt(r23067);
double r23069 = r23068 - r23063;
double r23070 = r23062 * r23069;
double r23071 = sqrt(r23070);
double r23072 = r23061 * r23071;
return r23072;
}
double f(double re, double im) {
double r23073 = re;
double r23074 = -2.7970604259960813e+81;
bool r23075 = r23073 <= r23074;
double r23076 = 0.5;
double r23077 = 2.0;
double r23078 = -2.0;
double r23079 = r23078 * r23073;
double r23080 = r23077 * r23079;
double r23081 = sqrt(r23080);
double r23082 = r23076 * r23081;
double r23083 = -1.796065771880539e-203;
bool r23084 = r23073 <= r23083;
double r23085 = r23073 * r23073;
double r23086 = im;
double r23087 = r23086 * r23086;
double r23088 = r23085 + r23087;
double r23089 = sqrt(r23088);
double r23090 = sqrt(r23089);
double r23091 = sqrt(r23090);
double r23092 = 3.0;
double r23093 = 2.0;
double r23094 = r23092 / r23093;
double r23095 = pow(r23091, r23094);
double r23096 = r23095 * r23095;
double r23097 = r23091 * r23096;
double r23098 = r23097 - r23073;
double r23099 = r23077 * r23098;
double r23100 = sqrt(r23099);
double r23101 = r23076 * r23100;
double r23102 = 7.843338612132253e-202;
bool r23103 = r23073 <= r23102;
double r23104 = r23086 - r23073;
double r23105 = r23077 * r23104;
double r23106 = sqrt(r23105);
double r23107 = r23076 * r23106;
double r23108 = pow(r23086, r23093);
double r23109 = r23073 + r23089;
double r23110 = r23108 / r23109;
double r23111 = r23077 * r23110;
double r23112 = sqrt(r23111);
double r23113 = r23076 * r23112;
double r23114 = r23103 ? r23107 : r23113;
double r23115 = r23084 ? r23101 : r23114;
double r23116 = r23075 ? r23082 : r23115;
return r23116;
}



Bits error versus re



Bits error versus im
Results
if re < -2.7970604259960813e+81Initial program 48.9
Taylor expanded around -inf 11.3
if -2.7970604259960813e+81 < re < -1.796065771880539e-203Initial program 18.5
rmApplied add-sqr-sqrt18.5
Applied sqrt-prod18.5
rmApplied add-sqr-sqrt18.5
Applied sqrt-prod18.5
Applied sqrt-prod18.6
Applied associate-*l*18.6
Simplified18.7
rmApplied sqr-pow18.7
if -1.796065771880539e-203 < re < 7.843338612132253e-202Initial program 31.1
Taylor expanded around 0 33.8
if 7.843338612132253e-202 < re Initial program 49.1
rmApplied flip--49.1
Simplified37.0
Simplified37.0
Final simplification27.4
herbie shell --seed 2019297
(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)))))