add misc handlers, cleanup and fixes

X86Disassembler/X86/Handlers/Misc/RdtscHandler.cs

@@ -0,0 +1,59 @@
+namespace X86Disassembler.X86.Handlers.Misc;
+
+/// <summary>
+/// Handler for RDTSC instruction (0x0F 0x31)
+/// </summary>
+public class RdtscHandler : InstructionHandler
+{
+    /// <summary>
+    /// Initializes a new instance of the RdtscHandler class
+    /// </summary>
+    /// <param name="decoder">The instruction decoder that owns this handler</param>
+    public RdtscHandler(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)
+    {
+        // RDTSC is encoded as 0x0F 0x31
+        if (opcode != 0x0F)
+            return false;
+
+        // Check if we can read the second byte
+        if (!Decoder.CanReadByte())
+            return false;
+
+        // Check if the second byte is 0x31
+        byte secondByte = Decoder.PeakByte();
+        return secondByte == 0x31;
+    }
+
+    /// <summary>
+    /// Decodes a RDTSC 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.Rdtsc;
+        
+        // Read and discard the second byte (0x31)
+        if (!Decoder.CanReadByte())
+            return false;
+            
+        Decoder.ReadByte();
+        
+        // RDTSC has no operands
+        instruction.StructuredOperands = [];
+
+        return true;
+    }
+}