[Bug tree-optimization/46493] New: [4.3/4.4 Regression] ICE: verify_flow_info failed when casting-out attribute noreturn

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46493

           Summary: [4.3/4.4 Regression] ICE: verify_flow_info failed when
                    casting-out attribute noreturn
           Product: gcc
           Version: 4.4.6
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


Created attachment 22415
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22415
reduced testcase

+++ This bug was initially created as a clone of Bug #46165 +++

These two ICEs might be related. The testcase is very similiar. The first one
needs -fno-tree-ccp, the second one fails with just -O.

The testcase for PR46165 crashes in 4.4 with following message:
$ gcc -O -fno-tree-ccp pr46165.c  
pr46165.c: In function 'g':
pr46165.c:2: error: control flow in the middle of basic block 2
pr46165.c:2: 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.

With the attached testcase, however, it crashes with a different message:
$ gcc -O testcase.c 
testcase.c:1: warning: data definition has no type or storage class
testcase.c: In function 'g':
testcase.c:4: warning: initialization from incompatible pointer type
testcase.c:6: error: verify_flow_info: Incorrect fallthru 3->4
testcase.c:6: error: wrong insn in the fallthru edge
(barrier 7 6 16)
testcase.c:6: internal compiler error: in rtl_verify_flow_info, at
cfgrtl.c:2067
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

Tested revisions:
4.4 r166509 - crash (with yes,rtl,df checking)