0.5 \cdot \sqrt{2 \cdot \left(\sqrt{re \cdot re + im \cdot im} - re\right)}\begin{array}{l}
\mathbf{if}\;re \le -2.463228932581569 \cdot 10^{122}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(-2 \cdot re\right)}\\
\mathbf{elif}\;re \le -7.36720432236371972 \cdot 10^{-267}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(\left(\sqrt[3]{\sqrt{re \cdot re + im \cdot im}} \cdot \sqrt[3]{\sqrt{re \cdot re + im \cdot im}}\right) \cdot \sqrt[3]{\sqrt{re \cdot re + im \cdot im}} - re\right)}\\
\mathbf{elif}\;re \le -8.0555860969017378 \cdot 10^{-305}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(-\left(re + im\right)\right)}\\
\mathbf{elif}\;re \le 5.3944762495838531 \cdot 10^{143}:\\
\;\;\;\;0.5 \cdot \left(\sqrt{2} \cdot \left|\sqrt{\left|im\right|} \cdot \sqrt{\frac{\left|im\right|}{\sqrt{re \cdot re + im \cdot im} + re}}\right|\right)\\
\mathbf{else}:\\
\;\;\;\;0.5 \cdot \sqrt{2 \cdot \left(\left|im\right| \cdot \frac{\left|im\right|}{re + re}\right)}\\
\end{array}double f(double re, double im) {
double r132 = 0.5;
double r133 = 2.0;
double r134 = re;
double r135 = r134 * r134;
double r136 = im;
double r137 = r136 * r136;
double r138 = r135 + r137;
double r139 = sqrt(r138);
double r140 = r139 - r134;
double r141 = r133 * r140;
double r142 = sqrt(r141);
double r143 = r132 * r142;
return r143;
}
double f(double re, double im) {
double r144 = re;
double r145 = -2.463228932581569e+122;
bool r146 = r144 <= r145;
double r147 = 0.5;
double r148 = 2.0;
double r149 = -2.0;
double r150 = r149 * r144;
double r151 = r148 * r150;
double r152 = sqrt(r151);
double r153 = r147 * r152;
double r154 = -7.36720432236372e-267;
bool r155 = r144 <= r154;
double r156 = r144 * r144;
double r157 = im;
double r158 = r157 * r157;
double r159 = r156 + r158;
double r160 = sqrt(r159);
double r161 = cbrt(r160);
double r162 = r161 * r161;
double r163 = r162 * r161;
double r164 = r163 - r144;
double r165 = r148 * r164;
double r166 = sqrt(r165);
double r167 = r147 * r166;
double r168 = -8.055586096901738e-305;
bool r169 = r144 <= r168;
double r170 = r144 + r157;
double r171 = -r170;
double r172 = r148 * r171;
double r173 = sqrt(r172);
double r174 = r147 * r173;
double r175 = 5.394476249583853e+143;
bool r176 = r144 <= r175;
double r177 = sqrt(r148);
double r178 = fabs(r157);
double r179 = sqrt(r178);
double r180 = r160 + r144;
double r181 = r178 / r180;
double r182 = sqrt(r181);
double r183 = r179 * r182;
double r184 = fabs(r183);
double r185 = r177 * r184;
double r186 = r147 * r185;
double r187 = r144 + r144;
double r188 = r178 / r187;
double r189 = r178 * r188;
double r190 = r148 * r189;
double r191 = sqrt(r190);
double r192 = r147 * r191;
double r193 = r176 ? r186 : r192;
double r194 = r169 ? r174 : r193;
double r195 = r155 ? r167 : r194;
double r196 = r146 ? r153 : r195;
return r196;
}



Bits error versus re



Bits error versus im
Results
if re < -2.463228932581569e+122Initial program 55.7
Taylor expanded around -inf 9.5
if -2.463228932581569e+122 < re < -7.36720432236372e-267Initial program 19.7
rmApplied add-cube-cbrt20.2
if -7.36720432236372e-267 < re < -8.055586096901738e-305Initial program 29.8
rmApplied flip--30.6
Simplified30.6
Taylor expanded around -inf 30.6
if -8.055586096901738e-305 < re < 5.394476249583853e+143Initial program 40.2
rmApplied flip--40.0
Simplified31.4
rmApplied *-un-lft-identity31.4
Applied add-sqr-sqrt31.4
Applied times-frac31.4
Simplified31.2
Simplified29.0
rmApplied add-sqr-sqrt29.1
Applied add-sqr-sqrt29.2
Applied unswap-sqr29.2
rmApplied sqrt-prod29.2
Simplified21.6
if 5.394476249583853e+143 < re Initial program 63.1
rmApplied flip--63.1
Simplified48.1
rmApplied *-un-lft-identity48.1
Applied add-sqr-sqrt48.1
Applied times-frac48.1
Simplified48.1
Simplified47.7
Taylor expanded around inf 24.1
Final simplification19.8
herbie shell --seed 2020025
(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)))))