[Bug tree-optimization/77938] missing tailcall optimization in case when local variable escapes that goes out of scope before the possible tail call site

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77938

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |missed-optimization
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2016-10-11
            Summary|missing tailcall            |missing tailcall
                   |optimization in case when   |optimization in case when
                   |local variable escapes      |local variable escapes that
                   |                            |goes out of scope before
                   |                            |the possible tail call site
     Ever confirmed|0                           |1
           Severity|normal                      |enhancement

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Confirmed,  GCC Is very conservative here.  Basically any time a variable
escapes, tail call is not used.  This can be improved do to now GCC has a way
to track if a variable is in scope at the call site.