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nice big refactor

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bird_egop
2025-04-13 23:06:52 +03:00
parent 59df064ca4
commit 11a2cfada4
92 changed files with 981 additions and 1509 deletions
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110
X86Disassembler/X86/Handlers/Cmp/CmpRm32R32Handler.cs
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@ -37,118 +37,34 @@ public class CmpRm32R32Handler : InstructionHandler
// Set the mnemonic
instruction.Mnemonic = "cmp";
int position = Decoder.GetPosition();
// Save the original position to properly handle the ModR/M byte
int originalPosition = Decoder.GetPosition();
if (position >= Length)
if (originalPosition >= Length)
{
return false;
}
// Read the ModR/M byte
byte modRM = CodeBuffer[position++];
// Extract the fields from the ModR/M byte
byte mod = (byte)((modRM & 0xC0) >> 6); // Top 2 bits
byte reg = (byte)((modRM & 0x38) >> 3); // Middle 3 bits
byte rm = (byte)(modRM & 0x07); // Bottom 3 bits
var (mod, reg, rm, destOperand) = ModRMDecoder.ReadModRM();
// Get the register name for the reg field
string regName = GetRegister32(reg);
string regName = ModRMDecoder.GetRegisterName(reg, 32);
// Handle the different addressing modes
string rmOperand;
// Use the destOperand directly from ModRMDecoder
string rmOperand = destOperand;
if (mod == 3) // Direct register addressing
// If it's a direct register operand, we need to remove the size prefix
if (mod == 3)
{
// Get the register name for the r/m field
rmOperand = GetRegister32(rm);
rmOperand = ModRMDecoder.GetRegisterName(rm, 32);
}
else // Memory addressing
else if (rmOperand.StartsWith("dword ptr "))
{
// Handle SIB byte if needed
if (mod != 3 && rm == 4) // SIB byte present
{
if (position >= Length)
{
return false;
}
byte sib = CodeBuffer[position++];
// Extract the fields from the SIB byte
byte scale = (byte)((sib & 0xC0) >> 6);
byte index = (byte)((sib & 0x38) >> 3);
byte base_ = (byte)(sib & 0x07);
// TODO: Handle SIB byte properly
rmOperand = $"[complex addressing]";
}
else if (mod == 0 && rm == 5) // Displacement only addressing
{
if (position + 3 >= Length)
{
return false;
}
// Read the 32-bit displacement
uint disp = (uint)(CodeBuffer[position] |
(CodeBuffer[position + 1] << 8) |
(CodeBuffer[position + 2] << 16) |
(CodeBuffer[position + 3] << 24));
position += 4;
rmOperand = $"[0x{disp:X8}]";
}
else // Simple addressing modes
{
string baseReg = GetRegister32(rm);
if (mod == 0) // No displacement
{
rmOperand = $"[{baseReg}]";
}
else // Displacement
{
uint disp;
if (mod == 1) // 8-bit displacement
{
if (position >= Length)
{
return false;
}
// Sign-extend the 8-bit displacement
sbyte dispByte = (sbyte)CodeBuffer[position++];
disp = (uint)(int)dispByte;
// Format the displacement
string dispStr = dispByte < 0 ? $"-0x{-dispByte:X2}" : $"0x{dispByte:X2}";
rmOperand = $"[{baseReg}+{dispStr}]";
}
else // 32-bit displacement
{
if (position + 3 >= Length)
{
return false;
}
// Read the 32-bit displacement
disp = (uint)(CodeBuffer[position] |
(CodeBuffer[position + 1] << 8) |
(CodeBuffer[position + 2] << 16) |
(CodeBuffer[position + 3] << 24));
position += 4;
rmOperand = $"[{baseReg}+0x{disp:X8}]";
}
}
}
// Remove the "dword ptr " prefix as we'll handle the operands differently
rmOperand = rmOperand.Substring(10);
}
// Update the decoder position
Decoder.SetPosition(position);
// Set the operands
instruction.Operands = $"{rmOperand}, {regName}";