fixes

X86Disassembler/X86/Handlers/Ret/Retf16Handler.cs

@@ -0,0 +1,47 @@
+using X86Disassembler.X86.Operands;
+
+namespace X86Disassembler.X86.Handlers.Ret;
+
+/// <summary>
+/// Handler for RETF instruction with operand size prefix (0xCB with 0x66 prefix)
+/// </summary>
+public class Retf16Handler : InstructionHandler
+{
+    /// <summary>
+    /// Initializes a new instance of the Retf16Handler class
+    /// </summary>
+    /// <param name="decoder">The instruction decoder that owns this handler</param>
+    public Retf16Handler(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)
+    {
+        // RETF with operand size prefix is encoded as 0xCB with 0x66 prefix
+        // Only handle when the operand size prefix IS present
+        return opcode == 0xCB && Decoder.HasOperandSizePrefix();
+    }
+
+    /// <summary>
+    /// Decodes a RETF instruction with operand size prefix
+    /// </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.Retf;
+
+        // RETF has no operands
+        instruction.StructuredOperands = [];
+
+        return true;
+    }
+}

X86Disassembler/X86/Handlers/Ret/RetfHandler.cs

@@ -0,0 +1,48 @@
+using X86Disassembler.X86.Operands;
+
+namespace X86Disassembler.X86.Handlers.Ret;
+
+/// <summary>
+/// Handler for RETF instruction (0xCB)
+/// </summary>
+public class RetfHandler : InstructionHandler
+{
+    /// <summary>
+    /// Initializes a new instance of the RetfHandler class
+    /// </summary>
+    /// <param name="decoder">The instruction decoder that owns this handler</param>
+    public RetfHandler(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)
+    {
+        // RETF is encoded as 0xCB
+        // Only handle when the operand size prefix is NOT present
+        // This ensures 16-bit handlers get priority when the prefix is present
+        return opcode == 0xCB && !Decoder.HasOperandSizePrefix();
+    }
+
+    /// <summary>
+    /// Decodes a RETF 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.Retf;
+
+        // RETF has no operands
+        instruction.StructuredOperands = [];
+
+        return true;
+    }
+}

X86Disassembler/X86/Handlers/Ret/RetfImm16Handler.cs

@@ -0,0 +1,60 @@
+using X86Disassembler.X86.Operands;
+
+namespace X86Disassembler.X86.Handlers.Ret;
+
+/// <summary>
+/// Handler for RETF imm16 instruction with operand size prefix (0xCA with 0x66 prefix)
+/// </summary>
+public class RetfImm16Handler : InstructionHandler
+{
+    /// <summary>
+    /// Initializes a new instance of the RetfImm16Handler class
+    /// </summary>
+    /// <param name="decoder">The instruction decoder that owns this handler</param>
+    public RetfImm16Handler(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)
+    {
+        // RETF imm16 with operand size prefix is encoded as 0xCA with 0x66 prefix
+        // Only handle when the operand size prefix IS present
+        return opcode == 0xCA && Decoder.HasOperandSizePrefix();
+    }
+
+    /// <summary>
+    /// Decodes a RETF imm16 instruction with operand size prefix
+    /// </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.Retf;
+
+        // Check if we can read the immediate word
+        if (!Decoder.CanReadUShort())
+            return false;
+
+        // Read the immediate word (number of bytes to pop from stack)
+        ushort imm16 = Decoder.ReadUInt16();
+
+        // Create an immediate operand for the pop count
+        var immOperand = OperandFactory.CreateImmediateOperand(imm16, 16);
+
+        // Set the structured operands
+        instruction.StructuredOperands = 
+        [
+            immOperand
+        ];
+
+        return true;
+    }
+}

X86Disassembler/X86/Handlers/Ret/RetfImmHandler.cs

@@ -0,0 +1,61 @@
+using X86Disassembler.X86.Operands;
+
+namespace X86Disassembler.X86.Handlers.Ret;
+
+/// <summary>
+/// Handler for RETF imm16 instruction (0xCA)
+/// </summary>
+public class RetfImmHandler : InstructionHandler
+{
+    /// <summary>
+    /// Initializes a new instance of the RetfImmHandler class
+    /// </summary>
+    /// <param name="decoder">The instruction decoder that owns this handler</param>
+    public RetfImmHandler(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)
+    {
+        // RETF imm16 is encoded as 0xCA
+        // Only handle when the operand size prefix is NOT present
+        // This ensures 16-bit handlers get priority when the prefix is present
+        return opcode == 0xCA && !Decoder.HasOperandSizePrefix();
+    }
+
+    /// <summary>
+    /// Decodes a RETF imm16 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.Retf;
+
+        // Check if we can read the immediate word
+        if (!Decoder.CanReadUShort())
+            return false;
+
+        // Read the immediate word (number of bytes to pop from stack)
+        ushort imm16 = Decoder.ReadUInt16();
+
+        // Create an immediate operand for the pop count
+        var immOperand = OperandFactory.CreateImmediateOperand(imm16, 16);
+
+        // Set the structured operands
+        instruction.StructuredOperands = 
+        [
+            immOperand
+        ];
+
+        return true;
+    }
+}