[Bug tree-optimization/46507] std::get and devirtualization on non-automatic variables

[glisse at gcc dot gnu.org]

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

Marc Glisse <glisse at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|std::tuple missed           |std::get and
                   |optimization                |devirtualization on
                   |                            |non-automatic variables

--- Comment #5 from Marc Glisse <glisse at gcc dot gnu.org> ---
I just read this comment in ipa-prop.c: "only for automatically allocated
objects but at the moment we devirtualize only these". And indeed, if we define
an automatic variable of type A and call arg_tuple_test on it (and that call is
inlined), then the call to f is devirtualized. So this is a known limitation of
the current devirtualization code. I don't think there is anything we can do at
the library level.