Function luaV_execute

lua/lvm.c:428–828

void luaV_execute (lua_State *L, int nexeccalls) {
  LClosure *cl;
  StkId base;
  TValue *k;
  const Instruction *pc;
 reentry:  /* entry point */
  lua_assert(isLua(L->ci));
  pc = L->savedpc;
  cl = &clvalue(L->ci->func)->l;
  base = L->base;
  k = cl->p->k;
  /* main loop of interpreter */
  for (;;) {
    const Instruction i = *pc++;
    StkId ra;
    if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
        (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
      traceexec(L, pc);
      if (L->status == LUA_YIELD) {  /* did hook yield? */
        L->savedpc = pc - 1;
        return;
      }
      base = L->base;
    }
    /* warning!! several calls may realloc the stack and invalidate `ra' */
    ra = RA(i);
    lua_assert(base == L->base && L->base == L->ci->base);
    lua_assert(base <= L->top && L->top <= L->stack + L->stacksize);
    lua_assert(L->top == L->ci->top || luaG_checkopenop(i));
    switch (GET_OPCODE(i)) {
      case OP_MOVE: {
        assign_op(GET_OPCODE(i));
        continue;
      }
      case OP_LOADK: {
        TValue *rb = RKB(i);
        const TValue *tm = luaT_gettmbyobj(L, rb, TM_TYPE);
        if (ttisuserdata(rb) && !ttisnil(tm)) {
           Protect(Arith(L, ra, rb, KBx(i), TM_TYPE));
        } else {
          setobj2s(L, ra, KBx(i));
        }
        continue;
      }
      case OP_LOADBOOL: {
        setbvalue(ra, GETARG_B(i));
        if (GETARG_C(i)) pc++;  /* skip next instruction (if C) */
        continue;
      }
      case OP_LOADNIL: {
        TValue *rb = RB(i);
        do {
          setnilvalue(rb--);
        } while (rb >= ra);
        continue;
      }
      case OP_GETUPVAL: {
        int b = GETARG_B(i);