c - Complexity of specific function -

so need analyze complexity of function , express function of "x" , "epsilon". tried express through log base epsiolon , x parameter no avail.

double exhaustivesquareroot(double x, double epsilon) {     double result, step;     step = epsilon * epsilon;     result = 0.0;      while (abs(result*result - x) > epsilon && result < x)         result += result+step;      return result; }