http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45375
--- Comment #166 from Jan Hubicka <hubicka at gcc dot gnu.org> 2013-01-09 15:19:41 UTC --- Markus, the apperance of undefined references I fixed by patch above is highly sensitive to partitioning and inlining decision. Can you, please, check if the problem with PGO remains? It may be another instance of the same issue.