\frac{\log \left(\sqrt{re \cdot re + im \cdot im}\right)}{\log 10}\begin{array}{l}
\mathbf{if}\;re \leq -1.268063321609487 \cdot 10^{+32}:\\
\;\;\;\;\sqrt{\frac{0.5}{\sqrt{\log 10}}} \cdot \left(\sqrt{0.5} \cdot \left(\left(\log 1 + \log \left(\frac{-1}{re}\right) \cdot -2\right) \cdot {\left(\frac{1}{{\left(\log 10\right)}^{3}}\right)}^{0.25}\right)\right)\\
\mathbf{elif}\;re \leq -4.17385497808198 \cdot 10^{-261}:\\
\;\;\;\;\frac{0.5}{\sqrt{\log 10}} \cdot \left(\log \left(re \cdot re + im \cdot im\right) \cdot \frac{1}{\sqrt{\log 10}}\right)\\
\mathbf{elif}\;re \leq 2.046877101973681 \cdot 10^{-198}:\\
\;\;\;\;\frac{0.5}{\sqrt{\log 10}} \cdot \left(\left(\log 1 + 2 \cdot \log im\right) \cdot \sqrt{\frac{1}{\log 10}}\right)\\
\mathbf{elif}\;re \leq 5.756838278404119 \cdot 10^{+130}:\\
\;\;\;\;\frac{0.5}{\sqrt{\log 10}} \cdot \left(\log \left(re \cdot re + im \cdot im\right) \cdot \frac{1}{\sqrt{\log 10}}\right)\\
\mathbf{else}:\\
\;\;\;\;\sqrt{\frac{0.5}{\sqrt{\log 10}}} \cdot \left(\sqrt{\frac{0.5}{\sqrt{\log 10}}} \cdot \frac{\log 1 + 2 \cdot \log re}{\sqrt{\log 10}}\right)\\
\end{array}double code(double re, double im) {
return (((double) log(((double) sqrt(((double) (((double) (re * re)) + ((double) (im * im)))))))) / ((double) log(10.0)));
}
double code(double re, double im) {
double VAR;
if ((re <= -1.268063321609487e+32)) {
VAR = ((double) (((double) sqrt((0.5 / ((double) sqrt(((double) log(10.0))))))) * ((double) (((double) sqrt(0.5)) * ((double) (((double) (((double) log(1.0)) + ((double) (((double) log((-1.0 / re))) * -2.0)))) * ((double) pow((1.0 / ((double) pow(((double) log(10.0)), 3.0))), 0.25))))))));
} else {
double VAR_1;
if ((re <= -4.17385497808198e-261)) {
VAR_1 = ((double) ((0.5 / ((double) sqrt(((double) log(10.0))))) * ((double) (((double) log(((double) (((double) (re * re)) + ((double) (im * im)))))) * (1.0 / ((double) sqrt(((double) log(10.0)))))))));
} else {
double VAR_2;
if ((re <= 2.046877101973681e-198)) {
VAR_2 = ((double) ((0.5 / ((double) sqrt(((double) log(10.0))))) * ((double) (((double) (((double) log(1.0)) + ((double) (2.0 * ((double) log(im)))))) * ((double) sqrt((1.0 / ((double) log(10.0)))))))));
} else {
double VAR_3;
if ((re <= 5.756838278404119e+130)) {
VAR_3 = ((double) ((0.5 / ((double) sqrt(((double) log(10.0))))) * ((double) (((double) log(((double) (((double) (re * re)) + ((double) (im * im)))))) * (1.0 / ((double) sqrt(((double) log(10.0)))))))));
} else {
VAR_3 = ((double) (((double) sqrt((0.5 / ((double) sqrt(((double) log(10.0))))))) * ((double) (((double) sqrt((0.5 / ((double) sqrt(((double) log(10.0))))))) * (((double) (((double) log(1.0)) + ((double) (2.0 * ((double) log(re)))))) / ((double) sqrt(((double) log(10.0)))))))));
}
VAR_2 = VAR_3;
}
VAR_1 = VAR_2;
}
VAR = VAR_1;
}
return VAR;
}



Bits error versus re



Bits error versus im
Results
if re < -1.2680633216094869e32Initial program Error: 42.2 bits
rmApplied add-sqr-sqrtError: 42.2 bits
Applied pow1/2Error: 42.2 bits
Applied log-powError: 42.2 bits
Applied times-fracError: 42.2 bits
rmApplied add-sqr-sqrtError: 42.2 bits
Applied associate-*l*Error: 42.1 bits
SimplifiedError: 42.1 bits
Taylor expanded around -inf Error: 11.6 bits
SimplifiedError: 11.6 bits
if -1.2680633216094869e32 < re < -4.1738549780819797e-261 or 2.046877101973681e-198 < re < 5.75683827840411851e130Initial program Error: 20.2 bits
rmApplied add-sqr-sqrtError: 20.2 bits
Applied pow1/2Error: 20.2 bits
Applied log-powError: 20.2 bits
Applied times-fracError: 20.2 bits
rmApplied div-invError: 20.1 bits
if -4.1738549780819797e-261 < re < 2.046877101973681e-198Initial program Error: 30.9 bits
rmApplied add-sqr-sqrtError: 30.9 bits
Applied pow1/2Error: 30.9 bits
Applied log-powError: 30.9 bits
Applied times-fracError: 30.9 bits
Taylor expanded around 0 Error: 34.8 bits
SimplifiedError: 34.8 bits
if 5.75683827840411851e130 < re Initial program Error: 56.9 bits
rmApplied add-sqr-sqrtError: 56.9 bits
Applied pow1/2Error: 56.9 bits
Applied log-powError: 56.9 bits
Applied times-fracError: 56.9 bits
rmApplied add-sqr-sqrtError: 56.9 bits
Applied associate-*l*Error: 56.9 bits
SimplifiedError: 56.9 bits
Taylor expanded around inf Error: 7.8 bits
SimplifiedError: 7.8 bits
Final simplificationError: 18.3 bits
herbie shell --seed 2020200
(FPCore (re im)
:name "math.log10 on complex, real part"
:precision binary64
(/ (log (sqrt (+ (* re re) (* im im)))) (log 10.0)))