void Rewriter::rewrite_invokedynamic(address bcp, int offset, bool reverse) {

  {- -------------------------------------------
  (1) reverse 引数が false の場合には, 
      バイトコード命令中の Constant Pool index が埋まっている 4byte を 
      対応する Constant Pool Cache index に置き換える.
      (また, この 4byte は実行環境のエンディアンに従って書き込む)

      reverse 引数が true の場合には, 逆に元に戻す処理が行われる.
      ---------------------------------------- -}

      address p = bcp + offset;
      assert(p[-1] == Bytecodes::_invokedynamic, "not invokedynamic bytecode");
      if (!reverse) {
        int cp_index = Bytes::get_Java_u2(p);
        int cpc  = maybe_add_cp_cache_entry(cp_index);  // add lazily
        int cpc2 = add_secondary_cp_cache_entry(cpc);

        // Replace the trailing four bytes with a CPC index for the dynamic
        // call site.  Unlike other CPC entries, there is one per bytecode,
        // not just one per distinct CP entry.  In other words, the
        // CPC-to-CP relation is many-to-one for invokedynamic entries.
        // This means we must use a larger index size than u2 to address
        // all these entries.  That is the main reason invokedynamic
        // must have a five-byte instruction format.  (Of course, other JVM
        // implementations can use the bytes for other purposes.)
        Bytes::put_native_u4(p, constantPoolCacheOopDesc::encode_secondary_index(cpc2));
        // Note: We use native_u4 format exclusively for 4-byte indexes.
      } else {
        int cache_index = constantPoolCacheOopDesc::decode_secondary_index(
                            Bytes::get_native_u4(p));
        int secondary_index = cp_cache_secondary_entry_main_index(cache_index);
        int pool_index = cp_cache_entry_pool_index(secondary_index);
        assert(_pool->tag_at(pool_index).is_invoke_dynamic(), "wrong index");
        // zero out 4 bytes
        Bytes::put_Java_u4(p, 0);
        Bytes::put_Java_u2(p, pool_index);
      }
    }