[Bug rtl-optimization/48721] New: [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

           Summary: [4.6/4.7 Regression] ICE: verify_flow_info failed:
                    missing barrier after block 6 with
                    -foptimize-sibling-calls -fsched2-use-superblocks
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: zso...@seznam.cz
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


Created attachment 24070
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24070
reduced testcase

Compiler output:
$ gcc -O -foptimize-sibling-calls -fsched2-use-superblocks -fschedule-insns2
-mtune=core2 testcase.c 
testcase.c: In function 'internal_state_transition':
testcase.c:73:1: error: missing barrier after block 6
testcase.c:73:1: internal compiler error: verify_flow_info failed
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

Tested revisions:
r172826 - crash
4.6 r172337 - crash
4.5 r172337 - crash