add new add handlers

X86Disassembler/X86/Handlers/Add/AddAlImmHandler.cs

@@ -0,0 +1,65 @@
+using X86Disassembler.X86.Operands;
+
+namespace X86Disassembler.X86.Handlers.Add;
+
+/// <summary>
+/// Handler for ADD AL, imm8 instruction (opcode 04)
+/// </summary>
+public class AddAlImmHandler : InstructionHandler
+{
+    /// <summary>
+    /// Initializes a new instance of the AddAlImmHandler class
+    /// </summary>
+    /// <param name="decoder">The instruction decoder that owns this handler</param>
+    public AddAlImmHandler(InstructionDecoder decoder)
+        : base(decoder)
+    {
+    }
+
+    /// <summary>
+    /// Checks if this handler can decode the given opcode
+    /// </summary>
+    /// <param name="opcode">The opcode to check</param>
+    /// <returns>True if this handler can decode the opcode</returns>
+    public override bool CanHandle(byte opcode)
+    {
+        // ADD AL, imm8 is encoded as 04 ib
+        return opcode == 0x04;
+    }
+
+    /// <summary>
+    /// Decodes an ADD AL, imm8 instruction
+    /// </summary>
+    /// <param name="opcode">The opcode of the instruction</param>
+    /// <param name="instruction">The instruction object to populate</param>
+    /// <returns>True if the instruction was successfully decoded</returns>
+    public override bool Decode(byte opcode, Instruction instruction)
+    {
+        // Set the instruction type
+        instruction.Type = InstructionType.Add;
+
+        // Check if we have enough bytes for the immediate value
+        if (!Decoder.CanReadByte())
+        {
+            return false;
+        }
+
+        // Read the immediate value
+        byte imm8 = Decoder.ReadByte();
+
+        // Create the destination register operand (AL)
+        var destinationOperand = OperandFactory.CreateRegisterOperand(RegisterIndex.A, 8);
+
+        // Create the source immediate operand
+        var sourceOperand = OperandFactory.CreateImmediateOperand(imm8);
+
+        // Set the structured operands
+        instruction.StructuredOperands = 
+        [
+            destinationOperand,
+            sourceOperand
+        ];
+
+        return true;
+    }
+}

X86Disassembler/X86/Handlers/Add/AddR8Rm8Handler.cs

@@ -0,0 +1,65 @@
+using X86Disassembler.X86.Operands;
+
+namespace X86Disassembler.X86.Handlers.Add;
+
+/// <summary>
+/// Handler for ADD r8, r/m8 instruction (opcode 02)
+/// </summary>
+public class AddR8Rm8Handler : InstructionHandler
+{
+    /// <summary>
+    /// Initializes a new instance of the AddR8Rm8Handler class
+    /// </summary>
+    /// <param name="decoder">The instruction decoder that owns this handler</param>
+    public AddR8Rm8Handler(InstructionDecoder decoder)
+        : base(decoder)
+    {
+    }
+
+    /// <summary>
+    /// Checks if this handler can decode the given opcode
+    /// </summary>
+    /// <param name="opcode">The opcode to check</param>
+    /// <returns>True if this handler can decode the opcode</returns>
+    public override bool CanHandle(byte opcode)
+    {
+        // ADD r8, r/m8 is encoded as 02 /r
+        return opcode == 0x02;
+    }
+
+    /// <summary>
+    /// Decodes an ADD r8, r/m8 instruction
+    /// </summary>
+    /// <param name="opcode">The opcode of the instruction</param>
+    /// <param name="instruction">The instruction object to populate</param>
+    /// <returns>True if the instruction was successfully decoded</returns>
+    public override bool Decode(byte opcode, Instruction instruction)
+    {
+        // Set the instruction type
+        instruction.Type = InstructionType.Add;
+
+        // Check if we have enough bytes for the ModR/M byte
+        if (!Decoder.CanReadByte())
+        {
+            return false;
+        }
+
+        // Read the ModR/M byte
+        // For ADD r8, r/m8 (02 /r):
+        // - The reg field specifies the destination register
+        // - The r/m field with mod specifies the source operand (register or memory)
+        var (_, reg, _, sourceOperand) = ModRMDecoder.ReadModRM8();
+
+        // Create the destination register operand
+        var destinationOperand = OperandFactory.CreateRegisterOperand(reg, 8);
+
+        // Set the structured operands
+        instruction.StructuredOperands = 
+        [
+            destinationOperand,
+            sourceOperand
+        ];
+
+        return true;
+    }
+}

X86Disassembler/X86/Handlers/Add/AddRm8R8Handler.cs

@@ -0,0 +1,66 @@
+using X86Disassembler.X86.Operands;
+
+namespace X86Disassembler.X86.Handlers.Add;
+
+/// <summary>
+/// Handler for ADD r/m8, r8 instruction (opcode 00)
+/// </summary>
+public class AddRm8R8Handler : InstructionHandler
+{
+    /// <summary>
+    /// Initializes a new instance of the AddRm8R8Handler class
+    /// </summary>
+    /// <param name="decoder">The instruction decoder that owns this handler</param>
+    public AddRm8R8Handler(InstructionDecoder decoder)
+        : base(decoder)
+    {
+    }
+
+    /// <summary>
+    /// Checks if this handler can decode the given opcode
+    /// </summary>
+    /// <param name="opcode">The opcode to check</param>
+    /// <returns>True if this handler can decode the opcode</returns>
+    public override bool CanHandle(byte opcode)
+    {
+        // ADD r/m8, r8 is encoded as 00 /r
+        return opcode == 0x00;
+    }
+
+    /// <summary>
+    /// Decodes an ADD r/m8, r8 instruction
+    /// </summary>
+    /// <param name="opcode">The opcode of the instruction</param>
+    /// <param name="instruction">The instruction object to populate</param>
+    /// <returns>True if the instruction was successfully decoded</returns>
+    public override bool Decode(byte opcode, Instruction instruction)
+    {
+        // Set the instruction type
+        instruction.Type = InstructionType.Add;
+
+        // Check if we have enough bytes for the ModR/M byte
+        if (!Decoder.CanReadByte())
+        {
+            return false;
+        }
+
+        // Read the ModR/M byte
+        // For ADD r/m8, r8 (00 /r):
+        // - The reg field specifies the source register
+        // - The r/m field with mod specifies the destination operand (register or memory)
+        var (_, reg, _, destinationOperand) = ModRMDecoder.ReadModRM8();
+        
+        // Create the source register operand
+        // For high registers, we need to set the IsHighRegister flag
+        var sourceOperand = OperandFactory.CreateRegisterOperand(reg, 8);
+
+        // Set the structured operands
+        instruction.StructuredOperands = 
+        [
+            destinationOperand,
+            sourceOperand
+        ];
+
+        return true;
+    }
+}

X86Disassembler/X86/Handlers/InstructionHandlerFactory.cs

@@ -269,6 +269,11 @@ public class InstructionHandlerFactory
         _handlers.Add(new AddR32Rm32Handler(_decoder));
         _handlers.Add(new AddRm32R32Handler(_decoder));
         _handlers.Add(new AddEaxImmHandler(_decoder));
+        
+        // Add 8-bit ADD handlers
+        _handlers.Add(new AddRm8R8Handler(_decoder)); // ADD r/m8, r8 (opcode 00)
+        _handlers.Add(new AddR8Rm8Handler(_decoder)); // ADD r8, r/m8 (opcode 02)
+        _handlers.Add(new AddAlImmHandler(_decoder)); // ADD AL, imm8 (opcode 04)
 
         // Add ADD immediate handlers from ArithmeticImmediate namespace
         _handlers.Add(new AddImmToRm8Handler(_decoder));

X86Disassembler/X86/RegisterIndex8.cs

@@ -0,0 +1,33 @@
+namespace X86Disassembler.X86;
+
+/// <summary>
+/// Represents the index values for x86 8-bit registers.
+/// These values correspond to the encoding used in ModR/M bytes
+/// for 8-bit register operand identification in x86 instructions.
+/// </summary>
+public enum RegisterIndex8
+{
+    /// <summary>AL register (low byte of EAX)</summary>
+    AL = 0,
+    
+    /// <summary>CL register (low byte of ECX)</summary>
+    CL = 1,
+    
+    /// <summary>DL register (low byte of EDX)</summary>
+    DL = 2,
+    
+    /// <summary>BL register (low byte of EBX)</summary>
+    BL = 3,
+    
+    /// <summary>AH register (high byte of EAX)</summary>
+    AH = 4,
+    
+    /// <summary>CH register (high byte of ECX)</summary>
+    CH = 5,
+    
+    /// <summary>DH register (high byte of EDX)</summary>
+    DH = 6,
+    
+    /// <summary>BH register (high byte of EBX)</summary>
+    BH = 7
+}