private void decodeArg(VMPreparedOperand op, bool byteMode)
{
int data = GetBits();
if ((data & 0x8000) != 0)
{
op.Type = VMOpType.VM_OPREG;
op.Data = (data >> 12) & 7;
op.Offset = op.Data;
AddBits(4);
}
else
{
if ((data & 0xc000) == 0)
{
op.Type = VMOpType.VM_OPINT;
if (byteMode)
{
op.Data = (data >> 6) & 0xff;
AddBits(10);
}
else
{
AddBits(2);
op.Data = ReadData(this);
}
}
else
{
op.Type = VMOpType.VM_OPREGMEM;
if ((data & 0x2000) == 0)
{
op.Data = (data >> 10) & 7;
op.Offset = op.Data;
op.Base = 0;
AddBits(6);
}
else
{
if ((data & 0x1000) == 0)
{
op.Data = (data >> 9) & 7;
op.Offset = op.Data;
AddBits(7);
}
else
{
op.Data = 0;
AddBits(4);
}
op.Base = ReadData(this);
}
}
}
}
private int GetOperand(VMPreparedOperand cmdOp)
{
int ret = 0;
if (cmdOp.Type == VMOpType.VM_OPREGMEM)
{
int pos = (cmdOp.Offset + cmdOp.Base) & VM_MEMMASK;
ret = Utilities.readIntLittleEndian(Mem, pos);
}
else
{
int pos = cmdOp.Offset;
ret = Utilities.readIntLittleEndian(Mem, pos);
}
return ret;
}