mark_stack_ptr   1154 gc.c               mark_stack_ptr = mark_stack;
mark_stack_ptr   1157 gc.c           #define MARK_STACK_EMPTY (mark_stack_ptr == mark_stack)
mark_stack_ptr   1187 gc.c               p = (mark_stack_ptr - mark_stack) + tmp_arry;
mark_stack_ptr   1358 gc.c           	    if (mark_stack_ptr - mark_stack < MARK_STACK_MAX) {
mark_stack_ptr   1359 gc.c           		*mark_stack_ptr = ptr;
mark_stack_ptr   1360 gc.c           		mark_stack_ptr++;