[Bug middle-end/52048] New: [4.7 Regression] -fcompare-debug failure with -O2 -fcompare-debug -fnon-call-exceptions -fno-tree-dominator-opts

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52048

             Bug #: 52048
           Summary: [4.7 Regression] -fcompare-debug failure with -O2
                    -fcompare-debug -fnon-call-exceptions
                    -fno-tree-dominator-opts
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz
                CC: aoliva@gcc.gnu.org
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


Created attachment 26510
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26510
autoreduced testcase (from g++.dg/torture/pr41775.C)

Compiler output:
$ gcc -O2 -fcompare-debug -fnon-call-exceptions -fno-tree-dominator-opts
testcase.C
gcc: error: testcase.C: -fcompare-debug failure

$ diff testcase.*gkd
187,188c187,188
<             (set (reg/f:DI 5 di [69])
<                 (plus:DI (reg/f:DI 5 di [orig:67 this ] [67])
---
>             (set (reg/f:DI 5 di [68])
>                 (plus:DI (reg/f:DI 5 di [orig:66 this ] [66])

Tested revisions:
r183676 - fail