static void writeMarkBit(VM_Address ref, int value) throws VM_PragmaUninterruptible { int oldValue = VM_Interface.readAvailableBitsWord(ref); int newValue = (oldValue & ~GC_MARK_BIT_MASK) | value;
static void writeMarkBit(VM_Address ref, VM_Word value) throws VM_PragmaUninterruptible { VM_Word oldValue = VM_Interface.readAvailableBitsWord(ref); VM_Word newValue = oldValue.and(GC_MARK_BIT_MASK.not()).or(value);
  static void writeMarkBit(VM_Address ref, int value) throws VM_PragmaUninterruptible {    int oldValue = VM_Interface.readAvailableBitsWord(ref);    int newValue = (oldValue & ~GC_MARK_BIT_MASK) | value;    VM_Interface.writeAvailableBitsWord(ref,newValue);  }