[Bug middle-end/50211] New: ICE: verify_flow_info: Incorrect fallthru 11->12 with -funroll-all-loops --param case-values-threshold=1

["zsojka at seznam dot cz" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50211

             Bug #: 50211
           Summary: ICE: verify_flow_info: Incorrect fallthru 11->12 with
                    -funroll-all-loops --param case-values-threshold=1
    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
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


Created attachment 25119
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25119
reduced testcase

Probably related to PR50200. --param case-values-threshold=1 seems to cause
various ICEs. This one has simpler testcase and less compiler flags.

Compiler output:
$ gcc -O -funroll-all-loops --param case-values-threshold=1 testcase.c
testcase.c: In function 'foo':
testcase.c:17:1: error: verify_flow_info: Incorrect fallthru 11->12
testcase.c:17:1: error: wrong insn in the fallthru edge
(barrier 96 101 105)
testcase.c:17:1: internal compiler error: in rtl_verify_flow_info, at
cfgrtl.c:2113
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

Tested revisions:
r178125 - crash