http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54006
--- Comment #1 from Hans-Peter Nilsson <hp at gcc dot gnu.org> 2012-07-17 22:44:11 UTC --- By "the macros just check for presence of certain patterns" I mean the code defining those macros, in c-family/c-cppbuiltin.c:cpp_atomic_builtins.
