View Compilation Error

0_0_30385440_7542.cpp: In function 'll G(ll)':
0_0_30385440_7542.cpp:113:23: error: call of overloaded 'log(ll&)' is ambiguous
     ll m = floor(log(x)/log(2));
                       ^
0_0_30385440_7542.cpp:113:23: note: candidates are:
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/cmath:44:0,
                 from 0_0_30385440_7542.cpp:12:
GCC4.9.2/x86_64-w64-mingw32/include/math.h:149:18: note: double log(double)
   double __cdecl log(double _X);
                  ^
In file included from 0_0_30385440_7542.cpp:12:0:
GCC4.9.2/x86_64-w64-mingw32/include/c++/cmath:361:3: note: constexpr long double std::log(long double)
   log(long double __x)
   ^
GCC4.9.2/x86_64-w64-mingw32/include/c++/cmath:357:3: note: constexpr float std::log(float)
   log(float __x)
   ^