Simplified CmpImmWithRm32Handler and added AndImmWithRm32Handler

X86Disassembler/X86/Handlers/And/AndImmWithRm32Handler.cs

@@ -0,0 +1,87 @@
+namespace X86Disassembler.X86.Handlers.And;
+
+/// <summary>
+/// Handler for AND r/m32, imm32 instruction (0x81 /4)
+/// </summary>
+public class AndImmWithRm32Handler : InstructionHandler
+{
+    /// <summary>
+    /// Initializes a new instance of the AndImmWithRm32Handler class
+    /// </summary>
+    /// <param name="codeBuffer">The buffer containing the code to decode</param>
+    /// <param name="decoder">The instruction decoder that owns this handler</param>
+    /// <param name="length">The length of the buffer</param>
+    public AndImmWithRm32Handler(byte[] codeBuffer, InstructionDecoder decoder, int length)
+        : base(codeBuffer, decoder, length)
+    {
+    }
+
+    /// <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)
+    {
+        if (opcode != 0x81)
+            return false;
+
+        // Check if the reg field of the ModR/M byte is 4 (AND)
+        int position = Decoder.GetPosition();
+        if (position >= Length)
+            return false;
+
+        byte modRM = CodeBuffer[position];
+        byte reg = (byte) ((modRM & 0x38) >> 3);
+
+        return reg == 4; // 4 = AND
+    }
+
+    /// <summary>
+    /// Decodes an AND r/m32, imm32 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 mnemonic
+        instruction.Mnemonic = "and";
+
+        // Read the ModR/M byte
+        var (mod, reg, rm, memOperand) = ModRMDecoder.ReadModRM();
+        
+        // Get the position after decoding the ModR/M byte
+        int position = Decoder.GetPosition();
+
+        // Check if we have enough bytes for the immediate value
+        if (position + 3 >= Length)
+        {
+            return false; // Not enough bytes for the immediate value
+        }
+
+        // Read the immediate value
+        uint imm32 = Decoder.ReadUInt32();
+
+        // Format the destination operand based on addressing mode
+        string destOperand;
+        if (mod == 3) // Register addressing mode
+        {
+            // Get 32-bit register name
+            destOperand = ModRMDecoder.GetRegisterName(rm, 32);
+        }
+        else // Memory addressing mode
+        {
+            // Memory operand already includes dword ptr prefix
+            destOperand = memOperand;
+        }
+        
+        // Format the immediate value
+        string immStr = $"0x{imm32:X8}";
+
+        // Set the operands
+        instruction.Operands = $"{destOperand}, {immStr}";
+
+        return true;
+    }
+}

X86Disassembler/X86/Handlers/Cmp/CmpImmWithRm32Handler.cs

@@ -48,28 +48,36 @@ public class CmpImmWithRm32Handler : InstructionHandler
         // Set the mnemonic
         instruction.Mnemonic = "cmp";
 
+        // Read the ModR/M byte
+        var (mod, reg, rm, memOperand) = ModRMDecoder.ReadModRM();
+        
+        // Get the position after decoding the ModR/M byte
         int position = Decoder.GetPosition();
 
-        if (position >= Length)
-        {
-            return false;
-        }
-
-        // Read the ModR/M byte
-        var (mod, reg, rm, destOperand) = ModRMDecoder.ReadModRM();
-
-        // Read the immediate value
+        // Check if we have enough bytes for the immediate value
         if (position + 3 >= Length)
         {
-            return false;
+            return false; // Not enough bytes for the immediate value
         }
 
-        // Read the immediate value in little-endian format
-        var imm = Decoder.ReadUInt32();
+        // Read the immediate value
+        uint imm32 = Decoder.ReadUInt32();
 
-        // Format the immediate value as expected by the tests (0x12345678)
-        // Note: The bytes are reversed to match the expected format in the tests
-        string immStr = $"0x{imm:X8}";
+        // Format the destination operand based on addressing mode
+        string destOperand;
+        if (mod == 3) // Register addressing mode
+        {
+            // Get 32-bit register name
+            destOperand = ModRMDecoder.GetRegisterName(rm, 32);
+        }
+        else // Memory addressing mode
+        {
+            // Memory operand already includes dword ptr prefix
+            destOperand = memOperand;
+        }
+        
+        // Format the immediate value
+        string immStr = $"0x{imm32:X8}";
 
         // Set the operands
         instruction.Operands = $"{destOperand}, {immStr}";

X86Disassembler/X86/Handlers/InstructionHandlerFactory.cs

@@ -373,6 +373,7 @@ public class InstructionHandlerFactory
     {
         // Add AND handlers
         _handlers.Add(new AndImmToRm8Handler(_codeBuffer, _decoder, _length));
+        _handlers.Add(new AndImmWithRm32Handler(_codeBuffer, _decoder, _length));
         _handlers.Add(new AndImmToRm32Handler(_codeBuffer, _decoder, _length));
         _handlers.Add(new AndImmToRm32SignExtendedHandler(_codeBuffer, _decoder, _length));