[Bug tree-optimization/87328] New: [9 Regression] ICE in do_rpo_vn, at tree-ssa-sccvn.c:6566

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87328

            Bug ID: 87328
           Summary: [9 Regression] ICE in do_rpo_vn, at
                    tree-ssa-sccvn.c:6566
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

gcc-9.0.0-alpha20180916 snapshot (r264351) ICEs when compiling the following
snippet w/ -O1 (-Og) -fno-tree-ccp -fno-tree-forwprop:

void
tp (void)
{
  int qt;

  qt = 0;
  if (qt != 0)
    {
      if (0)
        {
 h5:
          qt = 0;
          while (qt < 1)
            {
            }
        }

      ++qt;
    }

  goto h5;
}

% gcc-9.0.0-alpha20180916 -O1 -fno-tree-ccp -fno-tree-forwprop -c hyr6b31a.c
during GIMPLE pass: fre
hyr6b31a.c: In function 'tp':
hyr6b31a.c:22:1: internal compiler error: in do_rpo_vn, at
tree-ssa-sccvn.c:6566
22 | }
   | ^
0x6a712b do_rpo_vn
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180916/work/gcc-9-20180916/gcc/tree-ssa-sccvn.c:6566
0xe7946c execute
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180916/work/gcc-9-20180916/gcc/tree-ssa-sccvn.c:6726