[Bug tree-optimization/87202] New: [9 Regression] ICE in vn_reference_insert_pieces, at tree-ssa-sccvn.c:2752

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87202

            Bug ID: 87202
           Summary: [9 Regression] ICE in vn_reference_insert_pieces, at
                    tree-ssa-sccvn.c:2752
           Product: gcc
           Version: 9.0
            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-9.0.0-alpha20180902 snapshot (r264045) ICEs when compiling the following
snippet w/ -O1 (-Og):

int dk;

void
lv (void)
{
  int nm;

  dk = 1;
  while (dk != 0)
    {
    }

  if (1 / 0)
    {
      dk = 0;
      while (dk != 0)
        {
        }
    }

  for (;;)
    nm = !!dk;

  (void) nm;
}

% gcc-9.0.0-alpha20180902 -O1 -w -c znz65qpd.c
during GIMPLE pass: fre
znz65qpd.c: In function 'lv':
znz65qpd.c:25:1: internal compiler error: in vn_reference_insert_pieces, at
tree-ssa-sccvn.c:2752
25 | }
   | ^
0x69c31f vn_reference_insert_pieces(tree_node*, int, tree_node*,
vec<vn_reference_op_struct, va_heap, vl_ptr>, tree_node*, unsigned int)
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180902/work/gcc-9-20180902/gcc/tree-ssa-sccvn.c:2752
0xe5e153 vn_reference_lookup_or_insert_for_pieces
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180902/work/gcc-9-20180902/gcc/tree-ssa-sccvn.c:1728
0xe5ee1c vn_reference_lookup_3
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180902/work/gcc-9-20180902/gcc/tree-ssa-sccvn.c:2182
0xdaa643 walk_non_aliased_vuses(ao_ref*, tree_node*, void* (*)(ao_ref*,
tree_node*, unsigned int, void*), void* (*)(ao_ref*, tree_node*, void*, bool*),
tree_node* (*)(tree_node*), void*)
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180902/work/gcc-9-20180902/gcc/tree-ssa-alias.c:2833
0xe5b796 vn_reference_lookup(tree_node*, tree_node*, vn_lookup_kind,
vn_reference_s**, bool)
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180902/work/gcc-9-20180902/gcc/tree-ssa-sccvn.c:2630
0xe61748 visit_reference_op_load
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180902/work/gcc-9-20180902/gcc/tree-ssa-sccvn.c:3961
0xe61748 visit_stmt
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180902/work/gcc-9-20180902/gcc/tree-ssa-sccvn.c:4359
0xe630ac process_bb
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180902/work/gcc-9-20180902/gcc/tree-ssa-sccvn.c:5980
0xe64468 do_rpo_vn
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180902/work/gcc-9-20180902/gcc/tree-ssa-sccvn.c:6406
0xe651cc execute
       
/var/tmp/portage/sys-devel/gcc-9.0.0_alpha20180902/work/gcc-9-20180902/gcc/tree-ssa-sccvn.c:6598