[Bug tree-optimization/16987] [3.5 Regression] Excessive stack allocation (totally unused)

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-08-11 18:19 -------
Confirmed, I could not figure out what variables would overlap to save the stack space in 3.4.0 but 
there is a missed optimization here for 3.5.0:
  x.v = 3;
  y.v = v;
  T.3 = (const Type *)&y;
  T.5 = (const Type *)&x;
  y = *T.3 + *T.5;
  check (0);
  c.v = y;
  T.1 = (const Type *)&c;
  return *T.1;

but this is another place where the C++ (and C) front-ends are lowering &a->b (to (const Type *)&y) 
too soon.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |missed-optimization
   Last reconfirmed|0000-00-00 00:00:00         |2004-08-11 18:19:14
               date|                            |
            Summary|Excessive stack allocation  |[3.5 Regression] Excessive
                   |(totally unused)            |stack allocation (totally
                   |                            |unused)
   Target Milestone|---                         |3.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16987