[Bug tree-optimization/46507] std::tuple missed optimization

[miles at gnu dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46507

--- Comment #2 from miles at gnu dot org 2010-11-16 19:06:02 UTC ---
> Note that when I tried this same test yesterday, on a different machine (but
> the same compiler version), "extern_tuple_test" (but not "arg_tuple_test")
> _did_ result in a direct jump to A::f!  So maybe something funny is going on...

Actually this is wrong:  the version of "extern_tuple_test" which worked
yesterday was really this:

   void extern_tuple_test ()
   {
     extern const std::tuple<A> t;
     std::get<0>(t).f ();
   }

resulting in:

   extern_tuple_test():
    movl    $t, %edi
    jmp    A::f() const

Still, it seems like "arg_tuple_test" (and the previous version of
"extern_tuple_tst") should also received the same optimization.