http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48152
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-03-16 18:49:54 UTC --- Reproduced with: struct A { A (); ~A (); char buf[16]; virtual void bar (int, A, int); }; void foo (A *p) { A a; p->bar (6, a, 7); } using x86_64-linux -> x86_64-mingw32 cross and -O2 -g. Apparently TYPE_ARG_TYPES contains the original source types rather than how it is actually passed by invisible reference, will need to figure out where expand_call adjusts this and do something similar in prepare_call_arguments.