0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} - re\right)}\begin{array}{l}
\mathbf{if}\;re \le -6.4851444497691187 \cdot 10^{83}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(-1 \cdot re - re\right)}\\
\mathbf{elif}\;re \le 9.19480309029371711 \cdot 10^{-296}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(\sqrt{\sqrt{re \cdot re + im \cdot im} - re} \cdot \sqrt{\sqrt{re \cdot re + im \cdot im} - re}\right)}\\
\mathbf{elif}\;re \le 3.29386860837205705 \cdot 10^{-252}:\\
\;\;\;\;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 r23417 = 0.5;
double r23418 = 2.0;
double r23419 = re;
double r23420 = r23419 * r23419;
double r23421 = im;
double r23422 = r23421 * r23421;
double r23423 = r23420 + r23422;
double r23424 = sqrt(r23423);
double r23425 = r23424 - r23419;
double r23426 = r23418 * r23425;
double r23427 = sqrt(r23426);
double r23428 = r23417 * r23427;
return r23428;
}
double f(double re, double im) {
double r23429 = re;
double r23430 = -6.485144449769119e+83;
bool r23431 = r23429 <= r23430;
double r23432 = 0.5;
double r23433 = 2.0;
double r23434 = -1.0;
double r23435 = r23434 * r23429;
double r23436 = r23435 - r23429;
double r23437 = r23433 * r23436;
double r23438 = sqrt(r23437);
double r23439 = r23432 * r23438;
double r23440 = 9.194803090293717e-296;
bool r23441 = r23429 <= r23440;
double r23442 = r23429 * r23429;
double r23443 = im;
double r23444 = r23443 * r23443;
double r23445 = r23442 + r23444;
double r23446 = sqrt(r23445);
double r23447 = r23446 - r23429;
double r23448 = sqrt(r23447);
double r23449 = r23448 * r23448;
double r23450 = r23433 * r23449;
double r23451 = sqrt(r23450);
double r23452 = r23432 * r23451;
double r23453 = 3.293868608372057e-252;
bool r23454 = r23429 <= r23453;
double r23455 = r23443 - r23429;
double r23456 = r23433 * r23455;
double r23457 = sqrt(r23456);
double r23458 = r23432 * r23457;
double r23459 = 2.0;
double r23460 = pow(r23443, r23459);
double r23461 = r23446 + r23429;
double r23462 = r23460 / r23461;
double r23463 = r23433 * r23462;
double r23464 = sqrt(r23463);
double r23465 = r23432 * r23464;
double r23466 = r23454 ? r23458 : r23465;
double r23467 = r23441 ? r23452 : r23466;
double r23468 = r23431 ? r23439 : r23467;
return r23468;
}



Bits error versus re



Bits error versus im
Results
if re < -6.485144449769119e+83Initial program 49.8
Taylor expanded around -inf 11.3
if -6.485144449769119e+83 < re < 9.194803090293717e-296Initial program 21.2
rmApplied add-sqr-sqrt21.4
if 9.194803090293717e-296 < re < 3.293868608372057e-252Initial program 34.0
Taylor expanded around 0 32.7
if 3.293868608372057e-252 < re Initial program 48.4
rmApplied flip--48.3
Simplified36.3
Final simplification26.8
herbie shell --seed 2020049
(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)))))