private ByteBlock GetValue(Operand op)
{
ByteBlock result = ByteBlock.Empty;
switch (op.Type)
{
case Operand.OperandType.AddressBlock:
break;
case Operand.OperandType.Register:
return this.ReadRegister(op.Value.ToByte());
case Operand.OperandType.StackIndex:
break;
case Operand.OperandType.NumericByte:
case Operand.OperandType.NumericSByte:
case Operand.OperandType.NumericShort:
case Operand.OperandType.NumericUShort:
case Operand.OperandType.NumericInt:
case Operand.OperandType.NumericUInt:
case Operand.OperandType.NumericLong:
case Operand.OperandType.NumericULong:
case Operand.OperandType.NumericFloat:
case Operand.OperandType.NumericDouble:
case Operand.OperandType.LPString:
return op.Value;
default:
throw new ArgumentException();
}
return result;
}
private void LongArithmeticInstruction(DataOpcode opcode, Operand left, Operand right, Operand dest)
{
if (left.Type == Operand.OperandType.LPString || right.Type == Operand.OperandType.LPString)
{
throw new ArgumentException("can't do arithmetic on strings");
}
if (dest.Type != Operand.OperandType.AddressBlock && dest.Type != Operand.OperandType.Register && dest.Type != Operand.OperandType.StackIndex)
{
throw new ArgumentException("can't assign to a literal");
}
ByteBlock op1 = GetValue(left);
ByteBlock op2 = GetValue(right);
ulong uresult;
long sresult;
double fresult;
ByteBlock result;
if ((left.Type == Operand.OperandType.NumericByte || left.Type == Operand.OperandType.NumericUShort ||
left.Type == Operand.OperandType.NumericUInt || left.Type == Operand.OperandType.NumericULong ||
left.Type == Operand.OperandType.Register || left.Type == Operand.OperandType.AddressBlock) &&
(right.Type == Operand.OperandType.NumericByte || right.Type == Operand.OperandType.NumericUShort ||
right.Type == Operand.OperandType.NumericUInt || right.Type == Operand.OperandType.NumericULong ||
right.Type == Operand.OperandType.Register || right.Type == Operand.OperandType.AddressBlock)) // for now, register & memory values are only treated as ulongs. Fix
{
uresult = UnsignedArithmetic(opcode, op1.ToULong(), op2.ToULong());
if (dest.Type == Operand.OperandType.Register)
{
result = new ByteBlock(uresult);
WriteRegister((byte)dest.Value, result);
}
else
{
// this.Memory.WriteULongAt(uresult, (int)(((AddressBlock)dest.Value).Address)); fix
}
}
else if ((left.Type == Operand.OperandType.NumericSByte || left.Type == Operand.OperandType.NumericShort ||
left.Type == Operand.OperandType.NumericInt || left.Type == Operand.OperandType.NumericLong) &&
(right.Type == Operand.OperandType.NumericSByte || right.Type == Operand.OperandType.NumericShort ||
right.Type == Operand.OperandType.NumericInt || right.Type == Operand.OperandType.NumericLong))
{
sresult = SignedArithmetic(opcode, op1.ToLong(), op2.ToLong());
if (dest.Type == Operand.OperandType.Register)
{
result = new ByteBlock(sresult);
WriteRegister((byte)dest.Value, result);
}
else
{
// this.Memory.WriteLongAt(sresult, (int)(((AddressBlock)dest.Value).Address)); fix
}
}
else
{
fresult = FPArithmetic(opcode, op1.ToDouble(), op2.ToDouble());
if (dest.Type == Operand.OperandType.Register)
{
result = new ByteBlock(fresult);
WriteRegister((byte)dest.Value, result);
}
else
{
// this.Memory.WriteDoubleAt(fresult, (int)(((AddressBlock)dest.Value).Address)); fix
}
}
}
public void Execute()
{
ushort fullopcode = this.ReadUShort();
byte type = (byte)(fullopcode >> 8);
byte opcode = (byte)((fullopcode << 8) >> 8);
ushort arity = 0;
switch (type)
{
case 0x00: // Control flow instruction
CFOpcode cfopcode = (CFOpcode)opcode;
switch (cfopcode)
{
case CFOpcode.NOP:
break;
case CFOpcode.RET:
case CFOpcode.END: // no operands
break;
case CFOpcode.JMP:
case CFOpcode.JMPA:
case CFOpcode.CALL:
case CFOpcode.CALLA: // one operand, etc
arity = 1;
break;
case CFOpcode.JZ:
case CFOpcode.JNZ:
arity = 2;
break;
case CFOpcode.JE:
case CFOpcode.JNE:
case CFOpcode.JLT:
case CFOpcode.JGT:
case CFOpcode.JLTE:
case CFOpcode.JGTE:
arity = 3;
break;
default:
throw new ArgumentOutOfRangeException(); // will likely change
}
break;
case 0x01: // data instructions
DataOpcode dopcode = (DataOpcode)opcode;
switch (dopcode & (DataOpcode)0xE0) // seems only the top 3 bits are needed
{
case (DataOpcode)0x00: // stack arithmetic (or a move)
if (dopcode == DataOpcode.MOV) { arity = 2; }
break;
case (DataOpcode)0x40: // long arithmetic
switch (dopcode)
{
case DataOpcode.INVL:
case DataOpcode.NOTL:
case DataOpcode.BWNOTL:
arity = 2;
break;
default:
if (dopcode > (DataOpcode)0x54)
{
throw new ArgumentOutOfRangeException();
}
else
{
arity = 3;
break;
}
}
break;
case (DataOpcode)0x80: // stack operations
if (dopcode == DataOpcode.ARRAYALLOC)
{
arity = 2;
}
else
{
arity = 1;
}
break;
case (DataOpcode)0xA0: // conversions
arity = 2;
break;
}
break;
case 0x02: // system instructions
SysOpcode sopcode = (SysOpcode)opcode;
arity = 1;
break;
default:
throw new ArgumentOutOfRangeException();
}
if (arity > 0)
{
Operand[] operands = new Operand[arity];
byte flags = this.ReadByte();
int i;
for (i = 1; i <= arity; i++)
{
switch (flags >> 6)
{
case 0: // memory addr
operands[i] = new Operand(this, Operand.OperandType.AddressBlock); // addressblock code to be redone
break;
case 1: // register
operands[i] = new Operand(this, Operand.OperandType.Register);
break;
case 2: // stack index
operands[i] = new Operand(this, Operand.OperandType.StackIndex);
break;
case 3: // literal
byte valuetype = this.ReadByte();
operands[i] = new Operand(this, (Operand.OperandType)(valuetype - 3));
break;
}
flags <<= 2;
}
// check operand types
}
}
