public Instruction(ICollection <byte> prefixes, OpCode opCode, ModRegRM modReg = null, Constant constant = null)
{
Prefixes = prefixes;
OpCode = opCode;
ModRegRM = modReg;
Constant = constant;
}
public byte[] GetBytes(ModRegRM rm)
{
switch (rm.Mod)
{
case Mod.E1:
return(new byte[0]);
case Mod.E2:
return(BitConverter.GetBytes((sbyte)Value).Take(1).ToArray());
case Mod.E3:
return(BitConverter.GetBytes((int)Value));
case Mod.E4:
/*
* var reg = rm.RegisterOrMemory; // Correct?
* switch (reg.Size)
* {
* case Size.S8:
* return BitConverter.GetBytes((sbyte)Value).Take(1).ToArray();
*
* case Size.S16:
* return BitConverter.GetBytes((short)Value).ToArray();
*
* case Size.S32:
* return BitConverter.GetBytes((int)Value);
* }
* break;
*/
return(BitConverter.GetBytes((sbyte)Value).Take(1).ToArray());
}
throw new Exception();
}
private byte[] Encode(OpCode opCode, ModRegRM modReg = null, Constant constant = null)
{
List <byte> bytes = new List <byte>();
bytes.AddRange(opCode.GetBytes());
if (opCode.Type.HasModRegRM)
{
bytes.AddRange(modReg.Encode());
}
if (constant != null)
{
var label = constant as Label;
if (label != null)
{
var size = 0;
size += opCode.Size;
if (opCode.Type.HasModRegRM)
{
size += modReg.Size;
}
if (opCode.Is32Bit)
{
bytes.AddRange(BitConverter.GetBytes((uint)0));
}
else
{
bytes.AddRange(BitConverter.GetBytes((ushort)0));
}
label.References.Add((uint)(Offset + size));
}
else
{
if (opCode.Is32Bit)
{
bytes.AddRange(BitConverter.GetBytes((uint)constant));
}
else
{
bytes.AddRange(BitConverter.GetBytes((ushort)constant));
}
}
}
return(bytes.ToArray());
}
public byte[] Encode()
{
var bytes = new List <byte>();
bytes.AddRange(OpCode.GetBytes());
if (OpCode.Type.HasModRegRM && ModRegRM != null)
{
bytes.AddRange(ModRegRM.Encode());
}
if (Constant != null)
{
var label = Constant as Label;
if (label != null)
{
var size = 0;
size += OpCode.Size;
if (OpCode.Type.HasModRegRM)
{
size += ModRegRM.Size;
}
label.References.Add((uint)size);
if (OpCode.Is32Bit)
{
bytes.AddRange(BitConverter.GetBytes((uint)0));
}
else
{
bytes.AddRange(BitConverter.GetBytes((ushort)0));
}
}
else
{
if (OpCode.Is32Bit)
{
bytes.AddRange(BitConverter.GetBytes((uint)Constant));
}
else
{
bytes.AddRange(BitConverter.GetBytes((ushort)Constant));
}
}
}
return(bytes.ToArray());
}
public Instruction(OpCode opCode, ModRegRM modReg = null, Constant constant = null)
{
OpCode = opCode;
ModRegRM = modReg;
Constant = constant;
}
public void Emit(OpCode opCode, ModRegRM modRegRm, Constant constant)
{
var data = new Instruction(opCode, modRegRm, constant);
Append(Encode(opCode, modRegRm, constant));
}
public void Emit(OpCode opCode, ModRegRM modRegRm)
{
var data = new Instruction(opCode, modRegRm);
Append(Encode(opCode, modRegRm));
}