[Bug tree-optimization/52523] Missing "uninitialized" warning in simple code

["manu at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52523

Manuel LÃpez-IbÃÃez <manu at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-03-08
                 CC|                            |manu at gcc dot gnu.org
             Blocks|                            |24639
     Ever Confirmed|0                           |1

--- Comment #1 from Manuel LÃpez-IbÃÃez <manu at gcc dot gnu.org> 2012-03-08 00:05:22 UTC ---
The SSA dump is a bit obscure to me:

int main() ()
{
  int x;
  int D.21721;
  int x.0;

<bb 2>:
  [pr52523.cc : 5:17] x.0_1 = x;
  [pr52523.cc : 5:17] std::basic_ostream<char>::operator<< ([pr52523.cc : 5]
&cout, x.0_1);

<bb 3>:
  [pr52523.cc : 6:16] std::basic_istream<char>::operator>> ([pr52523.cc : 6]
&cin, &x);

<bb 4>:
  x ={v} {CLOBBER};
  [pr52523.cc : 7:1] D.21721_2 = 0;

<L0>:
  [pr52523.cc : 7:1] return D.21721_2;

<L1>:
  x ={v} {CLOBBER};
  resx 1

}

but I guess that 'std::cin >> x' creates a VOP, and the warning machinery does
not work well with VOPs. See PR19430.