void CollectedHeap::pre_initialize() {

  {- -------------------------------------------
  (1) C2 JIT Compiler 用の処理. 
      _defer_initial_card_mark フィールドを初期化する (#TODO).
      ---------------------------------------- -}

      // Used for ReduceInitialCardMarks (when COMPILER2 is used);
      // otherwise remains unused.
    #ifdef COMPILER2
      _defer_initial_card_mark =    ReduceInitialCardMarks && can_elide_tlab_store_barriers()
                                 && (DeferInitialCardMark || card_mark_must_follow_store());
    #else
      assert(_defer_initial_card_mark == false, "Who would set it?");
    #endif
    }