1 files changed, 132 insertions, 0 deletions
diff --git a/llvm/tools/llvm-mca/Backend.cpp b/llvm/tools/llvm-mca/Backend.cpp
new file mode 100644
index 00000000000..890cbc14d86
--- /dev/null
+++ b/llvm/tools/llvm-mca/Backend.cpp
@@ -0,0 +1,132 @@
+//===--------------------- Backend.cpp --------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+///
+/// Implementation of class Backend which emulates an hardware OoO backend.
+///
+//===----------------------------------------------------------------------===//
+
+#include "Backend.h"
+#include "HWEventListener.h"
+#include "llvm/CodeGen/TargetSchedule.h"
+#include "llvm/Support/Debug.h"
+
+namespace mca {
+
+#define DEBUG_TYPE "llvm-mca"
+
+using namespace llvm;
+
+void Backend::addEventListener(HWEventListener *Listener) {
+  if (Listener)
+    Listeners.insert(Listener);
+}
+
+void Backend::runCycle(unsigned Cycle) {
+  notifyCycleBegin(Cycle);
+
+  if (!SM->hasNext()) {
+    notifyCycleEnd(Cycle);
+    return;
+  }
+
+  InstRef IR = SM->peekNext();
+  const InstrDesc *Desc = &IB->getOrCreateInstrDesc(STI, *IR.second);
+  while (DU->isAvailable(Desc->NumMicroOps) && DU->canDispatch(*Desc)) {
+    Instruction *NewIS = IB->createInstruction(STI, *DU, IR.first, *IR.second);
+    Instructions[IR.first] = std::unique_ptr<Instruction>(NewIS);
+    NewIS->setRCUTokenID(DU->dispatch(IR.first, NewIS));
+
+    // If this is a zero latency instruction, then we don't need to dispatch
+    // it. Instead, we can mark it as executed.
+    if (NewIS->isZeroLatency())
+      notifyInstructionExecuted(IR.first);
+
+    // Check if we have dispatched all the instructions.
+    SM->updateNext();
+    if (!SM->hasNext())
+      break;
+
+    // Prepare for the next round.
+    IR = SM->peekNext();
+    Desc = &IB->getOrCreateInstrDesc(STI, *IR.second);
+  }
+
+  notifyCycleEnd(Cycle);
+}
+
+void Backend::notifyCycleBegin(unsigned Cycle) {
+  DEBUG(dbgs() << "[E] Cycle begin: " << Cycle << '\n');
+  for (HWEventListener *Listener : Listeners)
+    Listener->onCycleBegin(Cycle);
+
+  DU->cycleEvent(Cycle);
+  HWS->cycleEvent(Cycle);
+}
+
+void Backend::notifyInstructionDispatched(unsigned Index) {
+  DEBUG(dbgs() << "[E] Instruction Dispatched: " << Index << '\n');
+  for (HWEventListener *Listener : Listeners)
+    Listener->onInstructionDispatched(Index);
+}
+
+void Backend::notifyInstructionReady(unsigned Index) {
+  DEBUG(dbgs() << "[E] Instruction Ready: " << Index << '\n');
+  for (HWEventListener *Listener : Listeners)
+    Listener->onInstructionReady(Index);
+}
+
+void Backend::notifyInstructionIssued(
+    unsigned Index, const ArrayRef<std::pair<ResourceRef, unsigned>> &Used) {
+  DEBUG(
+    dbgs() << "[E] Instruction Issued: " << Index << '\n';
+    for (const std::pair<ResourceRef, unsigned> &Resource : Used) {
+      dbgs() << "[E] Resource Used: [" << Resource.first.first << '.'
+             << Resource.first.second << "]\n";
+      dbgs() << "           cycles: " << Resource.second << '\n';
+    }
+  );
+
+  for (HWEventListener *Listener : Listeners)
+    Listener->onInstructionIssued(Index, Used);
+}
+
+void Backend::notifyInstructionExecuted(unsigned Index) {
+  DEBUG(dbgs() << "[E] Instruction Executed: " << Index << '\n');
+  for (HWEventListener *Listener : Listeners)
+    Listener->onInstructionExecuted(Index);
+
+  const Instruction &IS = *Instructions[Index];
+  DU->onInstructionExecuted(IS.getRCUTokenID());
+}
+
+void Backend::notifyInstructionRetired(unsigned Index) {
+  DEBUG(dbgs() << "[E] Instruction Retired: " << Index << '\n');
+  for (HWEventListener *Listener : Listeners)
+    Listener->onInstructionRetired(Index);
+
+  const Instruction &IS = *Instructions[Index];
+  DU->invalidateRegisterMappings(IS);
+  Instructions.erase(Index);
+}
+
+void Backend::notifyResourceAvailable(const ResourceRef &RR) {
+  DEBUG(dbgs() << "[E] Resource Available: [" << RR.first << '.' << RR.second
+               << "]\n");
+  for (HWEventListener *Listener : Listeners)
+    Listener->onResourceAvailable(RR);
+}
+
+void Backend::notifyCycleEnd(unsigned Cycle) {
+  DEBUG(dbgs() << "[E] Cycle end: " << Cycle << "\n\n");
+  for (HWEventListener *Listener : Listeners)
+    Listener->onCycleEnd(Cycle);
+}
+
+} // namespace mca.