I need some advice on how to determine the runtime of this loop : s=0  for ( i=1 , i <= 2^m ; i=i*2 ) {    s++ }return s With $C_1$ =  actions performed once before entering the loop and$C_2$ = actions performed one after entering the loop,I see that $T(m) = C_1 + C_2 \cdot 2^m$.How can I  determine $T(m)$? 
Runtime of this loop
algorithm analysis;runtime analysis;loops