65 }

    66 

    67 bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) {

    68   jbyte val = _byte_map[card_index];

    69   // It's already processed

    70   if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) {

    71     return false;

    72   }

    73   // Cached bit can be installed either on a clean card or on a claimed card.

    74   jbyte new_val = val;

    75   if (val == clean_card_val()) {

    76     new_val = (jbyte)deferred_card_val();

    77   } else {

    78     if (val & claimed_card_val()) {

    79       new_val = val | (jbyte)deferred_card_val();

    80     }

    81   }

    82   if (new_val != val) {

    83     Atomic::cmpxchg(new_val, &_byte_map[card_index], val);

    84   }

    85   return true;