namespace X86Disassembler.X86.Handlers.Cmp; using Operands; /// /// Handler for CMP r/m32, imm8 (sign-extended) instruction (0x83 /7) /// public class CmpImmWithRm32SignExtendedHandler : InstructionHandler { /// /// Initializes a new instance of the CmpImmWithRm32SignExtendedHandler class /// /// The instruction decoder that owns this handler public CmpImmWithRm32SignExtendedHandler(InstructionDecoder decoder) : base(decoder) { } /// /// Checks if this handler can decode the given opcode /// /// The opcode to check /// True if this handler can decode the opcode public override bool CanHandle(byte opcode) { if (opcode != 0x83) return false; // Check if the reg field of the ModR/M byte is 7 (CMP) if (!Decoder.CanReadByte()) return false; var reg = ModRMDecoder.PeakModRMReg(); return reg == 7; // 7 = CMP } /// /// Decodes a CMP r/m32, imm8 (sign-extended) instruction /// /// The opcode of the instruction /// The instruction object to populate /// True if the instruction was successfully decoded public override bool Decode(byte opcode, Instruction instruction) { // Set the instruction type instruction.Type = InstructionType.Cmp; if (!Decoder.CanReadByte()) { return false; } // Read the ModR/M byte var (_, _, _, destOperand) = ModRMDecoder.ReadModRM(); // Read the immediate value if (!Decoder.CanReadByte()) { return false; } // Read the immediate value as a signed byte and sign-extend it sbyte imm8 = (sbyte) Decoder.ReadByte(); // Create the immediate operand with sign extension var immOperand = OperandFactory.CreateImmediateOperand((uint)imm8); // Set the structured operands instruction.StructuredOperands = [ destOperand, immOperand ]; return true; } }