[Bug c/68619] New: error: loop with header 6 not in loop tree

["dcb314 at hotmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68619

            Bug ID: 68619
           Summary: error: loop with header 6 not in loop tree
           Product: gcc
           Version: 6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

Created attachment 36873
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=36873&action=edit
C source code

$ ../results/bin/gcc -O2 -c -w bug252.c
qwe_0.c: In function âfunc_6â:
qwe_0.c:195:10: error: loop with header 6 not in loop tree

qwe_0.c:195:10: internal compiler error: in verify_loop_structure, at
cfgloop.c:1639
0x7395d4 verify_loop_structure()
        ../../src/trunk/gcc/cfgloop.c:1639
0x9ec0a4 checking_verify_loop_structure
        ../../src/trunk/gcc/cfgloop.h:324
0x9ec0a4 loop_optimizer_init(unsigned int)
        ../../src/trunk/gcc/loop-init.c:106
0xd86fc4 init_reassoc
        ../../src/trunk/gcc/tree-ssa-reassoc.c:5049

Compiler is gcc trunk, dated 20151129.