[Bug c++/87974] New: ice in vect_get_vec_def_for_stmt_copy

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87974

            Bug ID: 87974
           Summary: ice in vect_get_vec_def_for_stmt_copy
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: dcb314 at hotmail dot com
  Target Milestone: ---

For this C++ code:

struct h {
  typedef int &c;
};
class i {
  struct j {
    using c = int *;
  };
  using as = j::c;
};
template <typename> class k {
public:
  using as = i::as;
  h::c operator[](long l) {
    k<int[]>::as d = 0;
    return d[l];
  }
};
class : public k<int[]> {
} a;
long c, f;
void m() {
  for (long b; b <= 6; b++)
    for (long g; g < b; g++) {
      unsigned long e = g;
      c = 0;
      for (; c < b; c++)
        f = e >>= 1;
      a[g] = f;
    }
}

compiled by recent gcc trunk and compiler flag -O3, does this:

during GIMPLE pass: vect
bug477.cc: In function ‘void m()’:
bug477.cc:21:6: internal compiler error: in vect_get_vec_def_for_stmt_copy, at
t
ree-vect-stmts.c:1615
   21 | void m() {
      |      ^
0x787b69 vect_get_vec_def_for_stmt_copy(vec_info*, tree_node*)
        ../../trunk/gcc/tree-vect-stmts.c:1615
0x787b69 vect_get_vec_def_for_stmt_copy(vec_info*, tree_node*)
        ../../trunk/gcc/tree-vect-stmts.c:1607
0x787b69 vect_get_vec_defs_for_stmt_copy(vec_info*, vec<tree_node*, va_heap,
vl_
ptr>*, vec<tree_node*, va_heap, vl_ptr>*)
        ../../trunk/gcc/tree-vect-stmts.c:1634

This bug seems to have started sometime between revision 265846
and 265907.