0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} - re\right)}\begin{array}{l}
\mathbf{if}\;re \le -8.1561596166685901 \cdot 10^{125}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(-2 \cdot re\right)}\\
\mathbf{elif}\;re \le -3.80996693730795831 \cdot 10^{-103}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left({\left(\sqrt{re \cdot re + im \cdot im}\right)}^{\frac{3}{4}} \cdot \sqrt{\sqrt{\sqrt{re \cdot re + im \cdot im}}} - re\right)}\\
\mathbf{elif}\;re \le 2.33673518569970664 \cdot 10^{-296}:\\
\;\;\;\;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 code(double re, double im) {
return (0.5 * sqrt((2.0 * (sqrt(((re * re) + (im * im))) - re))));
}
double code(double re, double im) {
double VAR;
if ((re <= -8.15615961666859e+125)) {
VAR = (0.5 * sqrt((2.0 * (-2.0 * re))));
} else {
double VAR_1;
if ((re <= -3.8099669373079583e-103)) {
VAR_1 = (0.5 * sqrt((2.0 * ((pow(sqrt(((re * re) + (im * im))), 0.75) * sqrt(sqrt(sqrt(((re * re) + (im * im)))))) - re))));
} else {
double VAR_2;
if ((re <= 2.3367351856997066e-296)) {
VAR_2 = (0.5 * sqrt((2.0 * (im - re))));
} else {
VAR_2 = (0.5 * sqrt((2.0 * (pow(im, 2.0) / (sqrt(((re * re) + (im * im))) + re)))));
}
VAR_1 = VAR_2;
}
VAR = VAR_1;
}
return VAR;
}



Bits error versus re



Bits error versus im
Results
if re < -8.15615961666859e+125Initial program 55.6
Taylor expanded around -inf 9.1
if -8.15615961666859e+125 < re < -3.8099669373079583e-103Initial program 16.4
rmApplied add-sqr-sqrt16.4
Applied sqrt-prod16.5
rmApplied add-sqr-sqrt16.5
Applied sqrt-prod16.5
Applied sqrt-prod16.5
Applied associate-*r*16.5
Simplified16.6
rmApplied pow1/216.6
Applied sqrt-pow116.6
Applied pow-pow16.5
Simplified16.5
if -3.8099669373079583e-103 < re < 2.3367351856997066e-296Initial program 26.8
Taylor expanded around 0 34.8
if 2.3367351856997066e-296 < re Initial program 45.9
rmApplied flip--45.8
Simplified35.7
Final simplification28.0
herbie shell --seed 2020100
(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)))))