private void populateRTypeExecutors()
{
RTypeExecutors = new Dictionary <RTypeFunction, Action <RTypeInstruction, IStateAccessor> >
{
{ RTypeFunction.Add, (r, StateAccessor) => {
StateAccessor.WriteRegister(r.Rd, (uint)(((int)StateAccessor.ReadRegister(r.Rs)) + (int)(StateAccessor.ReadRegister(r.Rt))));
} },
{ RTypeFunction.UnsignedAdd, (r, StateAccessor) => {
StateAccessor.WriteRegister(r.Rd, StateAccessor.ReadRegister(r.Rs) + StateAccessor.ReadRegister(r.Rt));
} },
{ RTypeFunction.BitwiseAnd, (r, StateAccessor) => {
StateAccessor.WriteRegister(r.Rd, StateAccessor.ReadRegister(r.Rs) & StateAccessor.ReadRegister(r.Rt));
} },
{ RTypeFunction.Break, (r, StateAccessor) => {
StateAccessor.SetEpc(StateAccessor.GetPc());
StateAccessor.SetPc(0x3c);
StateAccessor.Skip();
} },
{ RTypeFunction.Divide, (r, StateAccessor) => {
var dividend = (int)StateAccessor.ReadRegister(r.Rs);
var divisor = (int)StateAccessor.ReadRegister(r.Rt);
StateAccessor.SetHi((uint)(dividend % divisor));
StateAccessor.SetLo((uint)(dividend / divisor));
} },
{ RTypeFunction.UnsignedDivide, (r, StateAccessor) => {
var dividend = StateAccessor.ReadRegister(r.Rs);
var divisor = StateAccessor.ReadRegister(r.Rt);
StateAccessor.SetHi(dividend % divisor);
StateAccessor.SetLo(dividend / divisor);
} },
{ RTypeFunction.JumpAndLinkRegister, (r, StateAccessor) => {
StateAccessor.WriteRegister(r.Rd, StateAccessor.GetPc() + 4);
StateAccessor.SetPc(StateAccessor.ReadRegister(r.Rs));
} },
{ RTypeFunction.JumpRegister, (r, StateAccessor) => {
StateAccessor.SetPc(StateAccessor.ReadRegister(r.Rs));
} },
{ RTypeFunction.MoveFromHi, (r, StateAccessor) => {
StateAccessor.WriteRegister(r.Rd, StateAccessor.GetHi());
} },
{ RTypeFunction.MoveFromLo, (r, StateAccessor) => {
StateAccessor.WriteRegister(r.Rd, StateAccessor.GetLo());
} },
{ RTypeFunction.MoveToHi, (r, StateAccessor) => {
StateAccessor.SetHi(StateAccessor.ReadRegister(r.Rs));
} },
{ RTypeFunction.MoveToLo, (r, StateAccessor) => {
StateAccessor.SetLo(StateAccessor.ReadRegister(r.Rs));
} },
{ RTypeFunction.Multiply, (r, StateAccessor) => {
var a = (long)(int)StateAccessor.ReadRegister(r.Rs);
var b = (long)(int)StateAccessor.ReadRegister(r.Rt);
long result = a * b;
StateAccessor.SetLo((uint)((int)result));
StateAccessor.SetHi((uint)(result >> 32));
} },
{ RTypeFunction.UnsignedMultiply, (r, StateAccessor) => {
var a = (ulong)StateAccessor.ReadRegister(r.Rs);
var b = (ulong)StateAccessor.ReadRegister(r.Rt);
var result = a * b;
StateAccessor.SetLo((uint)result);
StateAccessor.SetHi((uint)(result >> 32));
} },
{ RTypeFunction.BitwiseNor, (r, StateAccessor) => {
StateAccessor.WriteRegister(r.Rd, ~(StateAccessor.ReadRegister(r.Rs) | StateAccessor.ReadRegister(r.Rt)));
} },
{ RTypeFunction.BitwiseOr, (r, StateAccessor) => {
StateAccessor.WriteRegister(r.Rd, (StateAccessor.ReadRegister(r.Rs) | StateAccessor.ReadRegister(r.Rt)));
} },
{ RTypeFunction.ShiftLeftLogical, (r, StateAccessor) => {
var a = StateAccessor.ReadRegister(r.Rt);
var b = (int)r.Sa;
StateAccessor.WriteRegister(r.Rd, a << b);
} },
{ RTypeFunction.ShiftLeftLogicalVariable, (r, StateAccessor) => {
var a = StateAccessor.ReadRegister(r.Rt);
var b = (int)StateAccessor.ReadRegister(r.Rs);
StateAccessor.WriteRegister(r.Rd, a << b);
} },
{ RTypeFunction.SetOnLessThan, (r, StateAccessor) => {
var a = (int)StateAccessor.ReadRegister(r.Rs);
var b = (int)StateAccessor.ReadRegister(r.Rt);
StateAccessor.WriteRegister(r.Rd, a < b ? 1u : 0u);
} },
{ RTypeFunction.UnsignedSetOnLessThan, (r, StateAccessor) => {
var a = StateAccessor.ReadRegister(r.Rs);
var b = StateAccessor.ReadRegister(r.Rt);
StateAccessor.WriteRegister(r.Rd, a < b ? 1u : 0u);
} },
{ RTypeFunction.ShiftRightArithmetic, (r, StateAccessor) => {
var a = (int)StateAccessor.ReadRegister(r.Rt);
var b = (int)r.Sa;
StateAccessor.WriteRegister(r.Rd, (uint)(a >> b));
} },
{ RTypeFunction.ShiftRightArithmeticVariable, (r, StateAccessor) => {
var a = (int)StateAccessor.ReadRegister(r.Rt);
var b = (int)StateAccessor.ReadRegister(r.Rs);
StateAccessor.WriteRegister(r.Rd, (uint)(a >> b));
} },
{ RTypeFunction.ShiftRightLogical, (r, StateAccessor) => {
var a = StateAccessor.ReadRegister(r.Rt);
var b = (int)r.Sa;
StateAccessor.WriteRegister(r.Rd, a >> b);
} },
{ RTypeFunction.ShiftRightLogicalVariable, (r, StateAccessor) => {
var a = StateAccessor.ReadRegister(r.Rt);
var b = (int)StateAccessor.ReadRegister(r.Rs);
StateAccessor.WriteRegister(r.Rd, a >> b);
} },
{ RTypeFunction.Subtract, (r, StateAccessor) => {
var a = (int)StateAccessor.ReadRegister(r.Rs);
var b = (int)StateAccessor.ReadRegister(r.Rt);
StateAccessor.WriteRegister(r.Rd, (uint)(a - b));
} },
{ RTypeFunction.UnsignedSubtract, (r, StateAccessor) => {
var a = (int)StateAccessor.ReadRegister(r.Rs);
var b = (int)StateAccessor.ReadRegister(r.Rt);
StateAccessor.WriteRegister(r.Rd, (uint)(a - b));
} },
{ RTypeFunction.Syscall, (r, StateAccessor) => {
StateAccessor.SetEpc(StateAccessor.GetPc());
StateAccessor.SetPc(0x3c);
StateAccessor.Skip();
} },
{ RTypeFunction.BitwiseExclusiveOr, (r, StateAccessor) => {
StateAccessor.WriteRegister(r.Rd, (StateAccessor.ReadRegister(r.Rs) ^ StateAccessor.ReadRegister(r.Rt)));
} },
};
}