[Bug c++/56564] New: [4.7 Regression] movdqa on possibly-8-byte-aligned struct with -O3

["lukeocamden at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56564

             Bug #: 56564
           Summary: [4.7 Regression] movdqa on possibly-8-byte-aligned
                    struct with -O3
    Classification: Unclassified
           Product: gcc
           Version: 4.7.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: lukeocamden@gmail.com


#include <boost/exception_ptr.hpp>

struct foo { };

int main()
{
  boost::copy_exception(foo());
}

Compiling the above with -O3 results in the following instruction being
emitted:

movdqa  %xmm0,
_ZZN5boost16exception_detail27get_static_exception_objectINS0_10bad_alloc_EEENS_13exception_ptrEvE2ep(%rip)

But that symbol need not be 16-byte aligned (it's a boost::exception_ptr, which
contains a boost::shared_ptr, which is just a pair of pointers).

This crashes if
_ZZN5boost16exception_detail27get_static_exception_objectINS0_10bad_alloc_EEENS_13exception_ptrEvE2ep
comes from another object file where it is declared with 8-byte alignment.

Possible duplicate of 54167? Works fine with 4.6.2

Preprocessed source is attached.