internal static void ForLoop(Instruction i, ILuaVM vm) { var(a, sBx) = i.AsBx(); a += 1; // R(A)+=R(A+2) vm.PushValue(a + 2); vm.PushValue(a); vm.Arith(ArithOp.Add); vm.Replace(a); // R(A)<?=R(A+1) bool isPositiveStep = vm.ToNumber(a + 2) >= 0; if ((isPositiveStep && vm.Compare(a, a + 1, CompareOp.Le)) || (!isPositiveStep && vm.Compare(a + 1, a, CompareOp.Le))) { vm.AddPC(sBx); // pc+=sBx vm.Copy(a, a + 3); // R(A+3)=R(A) } }
private static void Compare(Instruction i, ILuaVM vm, CompareOp op) { var(a, b, c) = i.ABC(); vm.GetRK(b); vm.GetRK(c); if (vm.Compare(-2, -1, op) != (a != 0)) { vm.AddPC(1); } vm.Pop(2); }
/// <summary> /// R(A) += R(A + 2) /// if R(A) <?= R(A + 1) { /// pc += sBx /// R(A + 3) = R(A) /// } /// </summary> public static void ForLoop(Instruction ins, ILuaVM vm) { ins.AsBx(out var a, out var sbx); a += 1; // R(A) += R(A + 2) vm.PushValue(a + 2); vm.PushValue(a); vm.Arith(EArithOp.Add); vm.Replace(a); var isPositiveStep = vm.ToNumber(a + 2) >= 0; if (isPositiveStep && vm.Compare(a, a + 1, ECompOp.Le) || !isPositiveStep && vm.Compare(a + 1, a, ECompOp.Le)) { // pc += sBx vm.AddPC(sbx); // R(A + 3) = R(A) vm.Copy(a, a + 3); } }
/// <summary> /// if ((RK(B) op RK(C)) != A) /// pc++ /// </summary> private static void Compare(Instruction ins, ILuaVM vm, ECompOp op) { ins.ABC(out var a, out var b, out var c); vm.GetRK(b); vm.GetRK(c); if (vm.Compare(-2, -1, op) != (a != 0)) { vm.AddPC(1); } vm.Pop(2); }