void Bytecodes::def(Code code, const char* name, const char* format, const char* wide_format, BasicType result_type, int depth, bool can_trap, Code java_code) {

  {- -------------------------------------------
  (1) (assert)
      ---------------------------------------- -}

      assert(wide_format == NULL || format != NULL, "short form must exist if there's a wide form");

  {- -------------------------------------------
  (1) フィールドの初期化 (_name, _result_type, _depth, _lengths, _java_code)
      ---------------------------------------- -}

      int len  = (format      != NULL ? (int) strlen(format)      : 0);
      int wlen = (wide_format != NULL ? (int) strlen(wide_format) : 0);
      _name          [code] = name;
      _result_type   [code] = result_type;
      _depth         [code] = depth;
      _lengths       [code] = (wlen << 4) | (len & 0xF);
      _java_code     [code] = java_code;

  {- -------------------------------------------
  (1) Bytecodes::compute_flags() で format 文字列を解析し, 
      解析結果を _flags フィールドにセット.
      ---------------------------------------- -}

      int bc_flags = 0;
      if (can_trap)           bc_flags |= _bc_can_trap;
      if (java_code != code)  bc_flags |= _bc_can_rewrite;
      _flags[(u1)code+0*(1<<BitsPerByte)] = compute_flags(format,      bc_flags);
      _flags[(u1)code+1*(1<<BitsPerByte)] = compute_flags(wide_format, bc_flags);

  {- -------------------------------------------
  (1) (assert)
      ---------------------------------------- -}

      assert(is_defined(code)      == (format != NULL),      "");
      assert(wide_is_defined(code) == (wide_format != NULL), "");
      assert(length_for(code)      == len, "");
      assert(wide_length_for(code) == wlen, "");
    }