[Bug c/105713] New: [gimplefe] need a way to specify TREE_ADDRESSABLE

[Bug c/105713] New: [gimplefe] need a way to specify TREE_ADDRESSABLE

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105713

            Bug ID: 105713
           Summary: [gimplefe] need a way to specify TREE_ADDRESSABLE
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: rguenth at gcc dot gnu.org
  Target Milestone: ---

For PR105711 a RTL expansion GIMPLE testcase would have been nice:

typedef char v2qi __attribute__((vector_size(2)));

void __GIMPLE (ssa,startwith("optimized"))
foo (__complex__ char c)
{
  __BB(2):
  __MEM <v2qi, 8> (&c) = _Literal (v2qi) { _Literal (char) 0, _Literal (char) 0
};
  return;
}

but here 'c' ends up TREE_ADDRESSABLE while with the original setup it is not.
That's because the C FE parsing marks 'c' addressable when parsing &c.  The
GIMPLE FE should fix this up on the optimistic side somehow and allow
specifying TREE_ADDRESSABLE at the declaration.

[Bug c/105713] [gimplefe] need a way to specify TREE_ADDRESSABLE

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105713

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |enhancement
             Blocks|                            |101057


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101057
[Bug 101057] [gimplefe] GIMPLE frontend issues

[Bug c/105713] [gimplefe] need a way to specify TREE_ADDRESSABLE

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105713

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-05-17

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
.

[Bug c/105713] [gimplefe] need a way to specify TREE_ADDRESSABLE

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105713

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Similarly DECL_NOT_GIMPLE_REG_P.  "easiest" to do with attributes on the
declaration I guess.  GIMPLE FE specific attributes should be not recognized
without -fgimple and should be prefixed g_addressable, g_not_gimple_reg_p?

Optimistic clearing is going to be difficult, we'd need to have a lot of
attributes that way.  There's a narrow subset of cases we "ignore"
& for addressability and __MEM parsing is separate so eventually we
can introduce a flag into the C frontend to not set TREE_ADDRESSABLE when
in some "context".