[Bug tree-optimization/37117] New: reinterpret_cast to different reference or pointer type is overoptimized with -O2

["trash at wobow dot com" <gcc-bugzilla at gcc dot gnu dot org>]

The following code outputs "123.456" with no optimization or "-O1", but outputs
a corrupted value when compiled with "-02" or even with "-O1 -fstrict-aliasing
-fschedule-insns2".

#include <iostream>
int main()
{
    // binary representation of double value 123.456
    unsigned long long ull = 0x405edd2f1a9fbe77ll;
    std::cout << reinterpret_cast<double &>(ull) << std::endl;
}


-- 
           Summary: reinterpret_cast to different reference or pointer type
                    is overoptimized with -O2
           Product: gcc
           Version: 4.3.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: trash at wobow dot com
  GCC host triplet: 2.6.24
GCC target triplet: 2.6.24


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37117