src/hotspot/share/c1/c1_LIRGenerator.cpp

*** 1581,1590 ****
--- 1581,1591 ----
    LIR_Address* elm_address = new LIR_Address(array.result(), index_op, array_header_size, T_ADDRESS);
    __ leal(LIR_OprFact::address(elm_address), elm_op);
  
    for (int i = 0; i < elem_klass->nof_nonstatic_fields(); i++) {
      ciField* inner_field = elem_klass->nonstatic_field_at(i);
+     assert(!inner_field->is_flattened(), "flattened fields must have been expanded");
      int obj_offset = inner_field->offset();
      int elm_offset = obj_offset - elem_klass->first_field_offset(); // object header is not stored in array.
  
      BasicType field_type = inner_field->type()->basic_type();
      switch (field_type) {