feedback

Author: boomanaiden154

llvm/lib/Target/X86/MCA/X86CustomBehaviour.cpp

@@ -41,6 +41,9 @@ void X86InstrPostProcess::useStackEngine(std::unique_ptr<Instruction> &Inst,
   // TODO(boomanaiden154): We currently do not handle PUSHF/POPF because we
   // have not done the necessary benchmarking to see if they are also
   // optimized by the stack engine.
+  // TODO: We currently just remove all RSP writes from stack operations. This
+  // is not fully correct because we do not model sync uops which will
+  // delay subsequent rsp using non-stack instructions.
   if (X86::isPOP(MCI.getOpcode()) || X86::isPUSH(MCI.getOpcode())) {
     auto *StackRegisterDef =
         llvm::find_if(Inst->getDefs(), [](const WriteState &State) {