public static ushort GetInstructionValue(Cpu8086 cpu, OpCodeManager.OpCodeFlag flag, Register segmentPrefix, int instruction, int instructionValue, int instructionDisplacement)
{
switch (instruction)
{
case (int)Register.AX:
case (int)Register.CX:
case (int)Register.DX:
case (int)Register.BX:
case (int)Register.SP:
case (int)Register.BP:
case (int)Register.SI:
case (int)Register.DI:
case (int)Register.IP:
case (int)Register.CS:
case (int)Register.DS:
case (int)Register.ES:
case (int)Register.SS:
return(cpu.GetRegister((Register)instruction));
case OpCodeManager.ARG_BYTE_REGISTER:
return(cpu.GetRegisterU8((Register)instructionValue));
case OpCodeManager.ARG_DEREFERENCE:
case OpCodeManager.ARG_MEMORY:
var address = GetInstructionRealAddress(cpu, segmentPrefix, instruction, instructionValue, instructionDisplacement);
return(flag.Has(OpCodeManager.OpCodeFlag.Size8) ? cpu.ReadU8(address) : cpu.ReadU16(address));
case OpCodeManager.ARG_CONSTANT:
return((ushort)instructionValue);
default:
throw new NotImplementedException();
}
}
public static void CalculateSubFlags(Cpu8086 cpu, OpCodeManager.OpCodeFlag flag, ushort value1, ushort value2, int result)
{
if (flag.Has(OpCodeManager.OpCodeFlag.Size8))
{
CalculateSubFlags8Bit(cpu, (byte)value1, (byte)value2, result);
}
else
{
CalculateSubFlags16Bit(cpu, value1, value2, result);
}
}
public static string OutputArgument(Register segmentPrefix, OpCodeManager.OpCodeFlag flag, int argument, int argumentValue, int argumentDisplacement)
{
if (argument == OpCodeManager.ARG_NONE)
{
return(null);
}
switch (argument)
{
case (int)Register.AX:
return("AX");
case (int)Register.CX:
return("CX");
case (int)Register.DX:
return("DX");
case (int)Register.BX:
return("BX");
case (int)Register.SP:
return("SP");
case (int)Register.BP:
return("BP");
case (int)Register.SI:
return("SI");
case (int)Register.DI:
return("DI");
case (int)Register.IP:
return("IP");
case (int)Register.CS:
return("CS");
case (int)Register.DS:
return("DS");
case (int)Register.ES:
return("ES");
case (int)Register.SS:
return("SS");
case unchecked ((int)Register.FLAGS):
return("FLAGS");
case OpCodeManager.ARG_BYTE_REGISTER:
switch ((Register)argumentValue)
{
case Register.AL:
return("AL");
case Register.CL:
return("CL");
case Register.DL:
return("DL");
case Register.BL:
return("BL");
case Register.AH:
return("AH");
case Register.CH:
return("CH");
case Register.DH:
return("DH");
case Register.BH:
return("BH");
default:
throw new NotImplementedException();
}
case OpCodeManager.ARG_DEREFERENCE:
string value;
switch (argumentValue)
{
case 0:
value = "BX+SI";
break;
case 1:
value = "BX+DI";
break;
case 2:
value = "BP+SI";
break;
case 3:
value = "BP+DI";
break;
case 4:
value = "SI";
break;
case 5:
value = "DI";
break;
case 6:
value = "BP";
break;
case 7:
value = "BX";
break;
default:
throw new NotImplementedException();
}
switch (segmentPrefix)
{
case Register.Invalid:
return(argumentDisplacement < 0 ? $"[{value}{argumentDisplacement}]" : $"[{value}+{argumentDisplacement}]");
case Register.ES:
return(argumentDisplacement < 0 ? $"[ES:{value}{argumentDisplacement}]" : $"[ES:{value}+{argumentDisplacement}]");
case Register.CS:
return(argumentDisplacement < 0 ? $"[CS:{value}{argumentDisplacement}]" : $"[CS:{value}+{argumentDisplacement}]");
case Register.SS:
return(argumentDisplacement < 0 ? $"[SS:{value}{argumentDisplacement}]" : $"[SS:{value}+{argumentDisplacement}]");
case Register.DS:
return(argumentDisplacement < 0 ? $"[DS:{value}{argumentDisplacement}]" : $"[DS:{value}+{argumentDisplacement}]");
default:
throw new NotImplementedException();
}
case OpCodeManager.ARG_MEMORY:
switch (segmentPrefix)
{
case Register.Invalid:
return($"[{argumentValue:X4}]");
case Register.ES:
return($"[ES:{argumentValue:X4}]");
case Register.CS:
return($"[CS:{argumentValue:X4}]");
case Register.SS:
return($"[SS:{argumentValue:X4}]");
case Register.DS:
return($"[DS:{argumentValue:X4}]");
default:
throw new NotImplementedException();
}
case OpCodeManager.ARG_FAR_MEMORY:
var segment = (uint)argumentValue >> 16;
var address = argumentValue & 0xFFFF;
return($"[{segment:X4}:{address:X4}]");
case OpCodeManager.ARG_CONSTANT:
return(flag.Has(OpCodeManager.OpCodeFlag.Size8) ? $"{argumentValue:X2}" : $"{argumentValue:X4}");
default:
throw new NotImplementedException();
}
}
public static bool Has(this OpCodeManager.OpCodeFlag flag, OpCodeManager.OpCodeFlag testFlag) => (flag & testFlag) != 0;