------- Comment #5 from pinskia at gcc dot gnu dot org 2009-03-18 21:57 ------- We used to check flag_unit_at_a_time in this function: /* Use register calling convention for local functions when possible. */ if (decl && TREE_CODE (decl) == FUNCTION_DECL && flag_unit_at_a_time && !profile_flag)
Which meant it never worked for C++ in 3.4 and above , for C, it always worked until 4.4 which removed the check. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39496