private void populateITypeExecutors()
{
ITypeExecutors = new Dictionary <Opcode, Action <ITypeInstruction, IStateAccessor> >
{
{ Opcode.AddImmediate, (r, StateAccessor) => {
var a = (int)StateAccessor.ReadRegister(r.Rs);
StateAccessor.WriteRegister(r.Rt, (uint)(a + ((short)r.Immediate)));
} },
{ Opcode.UnsignedAddImmediate, (r, StateAccessor) => {
var a = StateAccessor.ReadRegister(r.Rs);
StateAccessor.WriteRegister(r.Rt, (uint)(a + (short)r.Immediate));
} },
{ Opcode.BitwiseAndImmediate, (r, StateAccessor) => {
var a = StateAccessor.ReadRegister(r.Rs);
StateAccessor.WriteRegister(r.Rt, a & r.Immediate);
} },
{ Opcode.BranchOnEqual, (r, StateAccessor) => {
var rs = StateAccessor.ReadRegister(r.Rs);
var rt = StateAccessor.ReadRegister(r.Rt);
if (rs == rt)
{
StateAccessor.SetPc((uint)(StateAccessor.GetPc() + (short)(r.Immediate << 2)));
}
} },
{ Opcode.Branch, (r, StateAccessor) => {
var rs = (int)StateAccessor.ReadRegister(r.Rs);
var rt = r.Rt;
switch (rt)
{
case 0:
if (rs < 0)
{
StateAccessor.SetPc((uint)(StateAccessor.GetPc() + (short)(r.Immediate << 2)));
}
break;
case 1:
if (rs >= 0)
{
StateAccessor.SetPc((uint)(StateAccessor.GetPc() + (short)(r.Immediate << 2)));
}
break;
case 16:
StateAccessor.WriteRegister(31, StateAccessor.GetPc() + 4);
if (rs < 0)
{
StateAccessor.SetPc((uint)(StateAccessor.GetPc() + (short)(r.Immediate << 2)));
}
break;
case 17:
StateAccessor.WriteRegister(31, StateAccessor.GetPc() + 4);
if (rs >= 0)
{
StateAccessor.SetPc((uint)(StateAccessor.GetPc() + (short)(r.Immediate << 2)));
}
break;
default:
throw new InvalidOperationException(String.Format("Invalid Branch {0}", rt));
}
} },
{ Opcode.BranchOnGreaterThanZero, (r, StateAccessor) => {
var rs = (int)StateAccessor.ReadRegister(r.Rs);
var rt = StateAccessor.ReadRegister(r.Rt);
if (rs > 0)
{
StateAccessor.SetPc((uint)(StateAccessor.GetPc() + (short)(r.Immediate << 2)));
}
} },
{ Opcode.BranchOnLessThanOrEqualToZero, (r, StateAccessor) => {
var rs = (int)StateAccessor.ReadRegister(r.Rs);
var rt = StateAccessor.ReadRegister(r.Rt);
if (rs <= 0)
{
StateAccessor.SetPc((uint)(StateAccessor.GetPc() + (short)(r.Immediate << 2)));
}
} },
{ Opcode.BranchOnNotEqual, (r, StateAccessor) => {
var rs = StateAccessor.ReadRegister(r.Rs);
var rt = StateAccessor.ReadRegister(r.Rt);
if (rs != rt)
{
StateAccessor.SetPc((uint)(StateAccessor.GetPc() + (short)(r.Immediate << 2)));
}
} },
{ Opcode.LoadByte, (r, StateAccessor) => {
var ptr = (uint)(((short)r.Immediate) + (int)StateAccessor.ReadRegister(r.Rs));
byte dt;
StateAccessor.GetMemoryData(ptr, out dt);
var data = (uint)((int)((sbyte)(dt)));
StateAccessor.WriteRegister(r.Rt, data);
} },
{ Opcode.UnsignedLoadByte, (r, StateAccessor) => {
var ptr = (uint)(((short)r.Immediate) + (int)StateAccessor.ReadRegister(r.Rs));
byte dt;
StateAccessor.GetMemoryData(ptr, out dt);
var data = (uint)dt;
StateAccessor.WriteRegister(r.Rt, data);
} },
{ Opcode.LoadHalfword, (r, StateAccessor) => {
var ptr = (uint)(((short)r.Immediate) + (int)StateAccessor.ReadRegister(r.Rs));
UInt16 dt;
StateAccessor.GetMemoryData(ptr, out dt);
var data = (uint)((int)((short)DataConverterUInt16(dt)));
StateAccessor.WriteRegister(r.Rt, data);
} },
{ Opcode.UnsignedLoadHalfword, (r, StateAccessor) => {
var ptr = (uint)(((short)r.Immediate) + (int)StateAccessor.ReadRegister(r.Rs));
UInt16 dt;
StateAccessor.GetMemoryData(ptr, out dt);
var data = DataConverterUInt16(dt);
StateAccessor.WriteRegister(r.Rt, data);
} },
{ Opcode.LoadUpperImmediate, (r, StateAccessor) => {
StateAccessor.WriteRegister(r.Rt, r.Immediate << 16);
} },
{ Opcode.LoadWord, (r, StateAccessor) => {
var ptr = (uint)(((short)r.Immediate) + (int)StateAccessor.ReadRegister(r.Rs));
UInt32 data;
StateAccessor.GetMemoryData(ptr, out data);
data = DataConverterUInt32(data);
StateAccessor.WriteRegister(r.Rt, data);
} },
{ Opcode.BitwiseOrImmediate, (r, StateAccessor) => {
var a = StateAccessor.ReadRegister(r.Rs);
StateAccessor.WriteRegister(r.Rt, a | r.Immediate);
} },
{ Opcode.StoreByte, (r, StateAccessor) => {
var ptr = (uint)(((short)r.Immediate) + (int)StateAccessor.ReadRegister(r.Rs));
var data = (byte)(StateAccessor.ReadRegister(r.Rt));
StateAccessor.SetMemoryData(ptr, data);
} },
{ Opcode.SetOnLessThanImmediate, (r, StateAccessor) => {
var a = (int)StateAccessor.ReadRegister(r.Rs);
StateAccessor.WriteRegister(r.Rt, a < (short)r.Immediate ? 1u : 0u);
} },
{ Opcode.UnsignedSetOnLessThanImmediate, (r, StateAccessor) => {
var a = StateAccessor.ReadRegister(r.Rs);
StateAccessor.WriteRegister(r.Rt, a < r.Immediate ? 1u : 0u);
} },
{ Opcode.StoreHalfword, (r, StateAccessor) => {
var ptr = (uint)(((short)r.Immediate) + (int)StateAccessor.ReadRegister(r.Rs));
var dt = (ushort)StateAccessor.ReadRegister(r.Rt);
dt = DataConverterUInt16(dt);
StateAccessor.SetMemoryData(ptr, (ushort)dt);
} },
{ Opcode.StoreWord, (r, StateAccessor) => {
var ptr = (uint)(((short)r.Immediate) + (int)StateAccessor.ReadRegister(r.Rs));
var data = DataConverterUInt32(StateAccessor.ReadRegister(r.Rt));
StateAccessor.SetMemoryData(ptr, data);
} },
{ Opcode.BitwiseExclusiveOrImmediate, (r, StateAccessor) => {
var a = StateAccessor.ReadRegister(r.Rs);
StateAccessor.WriteRegister(r.Rt, a ^ r.Immediate);
} },
};
}