[Bug middle-end/46761] New: [4.6 Regression] -fgraphite-identity produces wrong code for array initialization arr[i] = i

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46761

           Summary: [4.6 Regression] -fgraphite-identity produces wrong
                    code for array initialization arr[i] = i
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: zso...@seznam.cz
                CC: s...@gcc.gnu.org
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


Created attachment 22599
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22599
reduced testcase

This might be the common cause of several testsuite failures that appear with
-fgraphite-identity in testflags.

Output:
$ gcc -O -fgraphite-identity pr46761.c
$ valgrind -q ./a.out 
==20462== Conditional jump or move depends on uninitialised value(s)
==20462==    at 0x40053F: main (pr46761.c:12)
==20462== 
Aborted

Tested revisions:
r167356 - fail
r165699 - fail
r161659 - OK
4.5 r166509 - OK