[Bug tree-optimization/19786] New: Aliasing optimisation bug

["sylvain dot pion at sophia dot inria dot fr" <gcc-bugzilla at gcc dot gnu dot org>]

The attached C++ program triggers an assertion violation when compiled with -O2
(it should not).
The assertion is not triggered when adding -fno-strict-aliasing, or when removing
-O2.  It is also working when slight changes to the program are made (see comments
in the source).  It is the smallest version of the program which allowed me to
reproduce the bug, but I did not try to look into the <vector> header.

It might be an aliasing bug in <vector>, I don't know.
Note that g++ 3.4 works fine.

-- 
           Summary: Aliasing optimisation bug
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: critical
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: sylvain dot pion at sophia dot inria dot fr
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19786