internal static void ForLoop(Instruction i, ref LuaVM vm)
{
var(a, sBx) = i.AsBx();
a += 1;
// R(A)+=R(A+2);
vm.PushValue(a + 2);
vm.PushValue(a);
vm.Arith(Constant.LUA_OPADD);
vm.Replace(a);
var isPositiveStep = vm.ToNumber(a + 2) >= 0;
if (
(isPositiveStep && vm.Compare(a, a + 1, Constant.LUA_OPLE)) ||
(!isPositiveStep && vm.Compare(a + 1, a, Constant.LUA_OPLE)))
{
// pc+=sBx; R(A+3)=R(A)
vm.AddPC(sBx);
vm.Copy(a, a + 3);
}
}
private static void Compare(Instruction i, ref LuaVM vm, CompareOp op)
{
var(a, b, c) = i.ABC();
vm.GetRK(b);
vm.GetRK(c);
var br = vm.Compare(-2, -1, op) != (a != 0);
if (br)
{
vm.AddPC(1);
}
vm.Pop(2);
}
internal static void _compare(Instruction i, ref LuaVM vm, CompareOp op)
{
var abc = i.ABC();
var a = abc.Item1;
var b = abc.Item2;
var c = abc.Item3;
vm.GetRK(b);
vm.GetRK(c);
if (vm.Compare(-2, -1, op) != (a != 0))
{
vm.AddPC(1);
}
vm.Pop(2);
}