Method CMPSOp

FEXCore/Source/Interface/Core/OpcodeDispatcher.cpp:3285–3403

}

void OpDispatchBuilder::CMPSOp(OpcodeArgs) {
  if (Op->Flags & FEXCore::X86Tables::DecodeFlags::FLAG_ADDRESS_SIZE) {
    LogMan::Msg::EFmt("Can't handle adddress size");
    DecodeFailure = true;
    return;
  }

  const auto Size = OpSizeFromSrc(Op);

  bool Repeat = Op->Flags & (FEXCore::X86Tables::DecodeFlags::FLAG_REPNE_PREFIX | FEXCore::X86Tables::DecodeFlags::FLAG_REP_PREFIX);
  if (!Repeat) {
    // Default DS prefix
    Ref Dest_RSI = MakeSegmentAddress(X86State::REG_RSI, Op->Flags, X86Tables::DecodeFlags::FLAG_DS_PREFIX);
    // Only ES prefix
    Ref Dest_RDI = MakeSegmentAddress(X86State::REG_RDI, 0, X86Tables::DecodeFlags::FLAG_ES_PREFIX, true);

    auto Src1 = _LoadMemAutoTSO(GPRClass, Size, Dest_RDI, Size);
    auto Src2 = _LoadMemAutoTSO(GPRClass, Size, Dest_RSI, Size);

    CalculateFlags_SUB(OpSizeFromSrc(Op), Src2, Src1);

    auto PtrDir = LoadDir(IR::OpSizeToSize(Size));

    // Offset the pointer
    Dest_RDI = Add(OpSize::i64Bit, Dest_RDI, PtrDir);
    StoreGPRRegister(X86State::REG_RDI, Dest_RDI);

    // Offset second pointer
    Dest_RSI = Add(OpSize::i64Bit, Dest_RSI, PtrDir);
    StoreGPRRegister(X86State::REG_RSI, Dest_RSI);
  } else {
    // Calculate flags early.
    CalculateDeferredFlags();

    bool REPE = Op->Flags & FEXCore::X86Tables::DecodeFlags::FLAG_REP_PREFIX;

    // If rcx = 0, skip the whole loop.
    Ref Counter = LoadGPRRegister(X86State::REG_RCX);
    auto OuterJump = CondJump(Counter, {COND_EQ});

    auto BeforeLoop = CreateNewCodeBlockAfter(GetCurrentBlock());
    SetFalseJumpTarget(OuterJump, BeforeLoop);
    SetCurrentCodeBlock(BeforeLoop);
    StartNewBlock();

    ForeachDirection([this, Op, Size, REPE](int32_t PtrDir) {
      IRPair<IROp_CondJump> InnerJump;
      auto JumpIntoLoop = Jump();

      // Setup for the loop
      auto LoopHeader = CreateNewCodeBlockAfter(GetCurrentBlock());
      SetCurrentCodeBlock(LoopHeader);
      StartNewBlock();
      SetJumpTarget(JumpIntoLoop, LoopHeader);

      // Working loop
      {
        // Default DS prefix