cannot locate symbol "log2" referenced by "libGLES_mgd.so"
The log2 function is a standard part of the C library since C99, so sounds like your host platform is using a really old C library.
What platform are you using, with what C library version?
Cheers,Pete
android 4.2.2 platform
but i think "log2" is a standard part of c++ 11 ?
float log2( float arg );
std::log2 - cppreference.com