s_used            243 lib/lua/lgc.c    int s_used = cast_int(max - L->stack);  /* part of stack in use */
s_used            249 lib/lua/lgc.c    if (4*s_used < L->stacksize &&
s_used            252 lib/lua/lgc.c    condhardstacktests(luaD_reallocstack(L, s_used));