[Bug debug/46252] New: [4.6 Regression] -fcompare-debug failure (length) with -O -frerun-cse-after-loop -fno-tree-loop-optimize -funroll-loops

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46252

           Summary: [4.6 Regression] -fcompare-debug failure (length) with
                    -O -frerun-cse-after-loop -fno-tree-loop-optimize
                    -funroll-loops
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: zso...@seznam.cz


Created attachment 22211
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22211
reduced testcase

Compiler output:
$ gcc -O -frerun-cse-after-loop -fno-tree-loop-optimize -funroll-loops
-fcompare-debug pr46252.c 
gcc: error: pr46252.c: -fcompare-debug failure (length)

Tested revisions:
r166105 - fail
r161659 - fail
r159696 - OK
4.5 r165781 - OK