[Bug tree-optimization/92203] New: [10 Regression] ICE in eliminate_stmt, at tree-ssa-sccvn.c:5492

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92203

            Bug ID: 92203
           Summary: [10 Regression] ICE in eliminate_stmt, at
                    tree-ssa-sccvn.c:5492
           Product: gcc
           Version: 10.0
            Status: UNCONFIRMED
          Keywords: ice-on-invalid-code
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

gcc-10.0.0-alpha20191020 snapshot (r277217) ICEs when compiling the following
testcase w/ -O2:

unsigned long int rr;

void
cw (int z9)
{
  int m5;
  unsigned long int vz = 0;
  long int *na;

  if (z9 == 0)
    rr = 0;
  else
    {
      na = (long int *) &m5;
      for (*na = 0; *na < 1; ++*na)
        {
          na = (long int *) &vz;
          rr /= 0;
        }
    }

  m5 = rr / 5;
  ++vz;
  if (vz != 0)
    while (z9 < 1)
      {
        if (m5 >= 0)
          rr += m5;

        na = (long int *) &rr;
        if (*na >= 0)
          rr = 0;
      }
}

% gcc-10.0.0-alpha20191020 -O2 -w -c vd3u37af.c
during GIMPLE pass: pre
vd3u37af.c: In function 'cw':
vd3u37af.c:4:1: internal compiler error: in eliminate_stmt, at
tree-ssa-sccvn.c:5492
    4 | cw (int z9)
      | ^~
0x6a3285 eliminate_dom_walker::eliminate_stmt(basic_block_def*,
gimple_stmt_iterator*)
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191020/work/gcc-10-20191020/gcc/tree-ssa-sccvn.c:5492
0xdf4ba5 eliminate_dom_walker::before_dom_children(basic_block_def*)
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191020/work/gcc-10-20191020/gcc/tree-ssa-sccvn.c:5908
0xdf4ba5 eliminate_dom_walker::before_dom_children(basic_block_def*)
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191020/work/gcc-10-20191020/gcc/tree-ssa-sccvn.c:5841
0x142113a dom_walker::walk(basic_block_def*)
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191020/work/gcc-10-20191020/gcc/domwalk.c:309
0xdece8d eliminate_with_rpo_vn(bitmap_head*)
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191020/work/gcc-10-20191020/gcc/tree-ssa-sccvn.c:6086
0xdd16c0 execute
       
/var/tmp/portage/sys-devel/gcc-10.0.0_alpha20191020/work/gcc-10-20191020/gcc/tree-ssa-pre.c:4234