will C++ 11 extern template help to reduce executable file size

I am using g++ on linux with C++ generic programming. I am not using "extern template" key word now, because I tried and sometimes it ended up with "undefined reference to". I know this is probably my fault, but I wouldn't take this risk. My question is, in addition to reducing compile time, will this key word also help to reduce the executable file size? I am suspecious that the executable file has multiple same objects in different modules in the same executable file...