[Bug tree-optimization/82954] New: [8 regression] ICE in fold_binary_loc, at fold-const.c:9061

[trippels at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82954

            Bug ID: 82954
           Summary: [8 regression] ICE in fold_binary_loc, at
                    fold-const.c:9061
           Product: gcc
           Version: 8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: trippels at gcc dot gnu.org
                CC: jakub at gcc dot gnu.org
  Target Milestone: ---

trippels@gcc67 ~ % cat stun.ii
struct A {
  struct {
    int __u6_addr8;
  } __in6_u;
};
struct B {
  B(A &);
};
unsigned a[0];
struct C {
  B m_fn1() const;
};
B C::m_fn1() const {
  A b;
  unsigned *c = reinterpret_cast<unsigned *>(b.__in6_u.__u6_addr8);
  c[0] = c[0] ^ 1;
  c[1] = c[1] ^ 1;
  c[2] = c[2] ^ a[0];
  c[3] = c[3] ^ a[1];
  return b;
}

trippels@gcc67 ~ % g++ -O2 -c stun.ii
during GIMPLE pass: store-merging
stun.ii: In member function ‘B C::m_fn1() const’:
stun.ii:13:3: internal compiler error: in fold_binary_loc, at fold-const.c:9061
 B C::m_fn1() const {
   ^
0xa96e20 fold_binary_loc(unsigned int, tree_code, tree_node*, tree_node*,
tree_node*)
        ../../gcc/gcc/fold-const.c:9058
0xa9d9da fold_build2_loc(unsigned int, tree_code, tree_node*, tree_node*,
tree_node*)
        ../../gcc/gcc/fold-const.c:12114
0x1524096 output_merged_store
        ../../gcc/gcc/gimple-ssa-store-merging.c:1873
0x1525d24 output_merged_stores
        ../../gcc/gcc/gimple-ssa-store-merging.c:2066
0x1525d24 terminate_and_process_chain
        ../../gcc/gcc/gimple-ssa-store-merging.c:2104
0x1525d24 terminate_and_release_chain
        ../../gcc/gcc/gimple-ssa-store-merging.c:996
0x1526234 terminate_all_aliasing_chains
        ../../gcc/gcc/gimple-ssa-store-merging.c:979
0x152684c process_store
        ../../gcc/gcc/gimple-ssa-store-merging.c:2403
0x152684c execute
        ../../gcc/gcc/gimple-ssa-store-merging.c:2511