http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57375
--- Comment #3 from davidxl at google dot com --- (In reply to Sriraman Tallam from comment #2) > IMO, This is working as expected. > > You define corei7 only in mv12-aux1.cc, so the compilation of mv12.C and > mv12-aux.cc do not see the corei7 version. The version resolver function > that is generated is a comdat function, and there are 2 copies generated for > the 2 source files with a call to foo, mv12.C and mv12-aux1.cc. However, one > of the copies is different, that generated when compiling mv12-aux1.cc > because it has the extra corei7 version. So, depending on the link order > whichever comdat copy gets kept either calls the corei7 version or not. > Usually, the linker keeps the first comdat copy seen so if you put > mv12-aux1.cc ahead of mv12.C, the corei7 version will be called and the > reverse will not call it. > > The fix is in the source. Either make every source file see the corei7 > version or hide it from all. > > The linker can be made to complain that the comdats differ if it could be > taught about version resolvers. This may be more involved. There is no need to conditionally declare/define corei7 version in one file only -- the additional time cost is very small. David
