Start using StringMap for TimingData

[knaumov]

Summary

In our downstream, we have a problem that some passes have their names exist only for the period of their execution. Because of the following structure, for compilations with temporary passes, it throws an error.
In this fix, I am handling the cases of having passes disappearing after use and not being called for a check of Timer for them.
This fix only adds the functionality to the time-passes flag but doesn't change its behavior for the rest cases.

[fedor.sergeev]

LGTM.

llvm/include/llvm/IR/PassTimingInfo.h

class TimePassesHandler {
   /// Value of this type is capable of uniquely identifying pass invocations.
   /// It is a pair of string Pass-Identifier (which for now is common
   /// to all the instance of a given pass) + sequential invocation counter.
   using PassInvocationID = std::pair<StringRef, unsigned>;
 
   /// A group of all pass-timing timers.
   TimerGroup TG;
 
+  using TimerVector = llvm::SmallVector<std::unique_ptr<Timer>, 4>;
   /// Map of timers for pass invocations
-  DenseMap<PassInvocationID, std::unique_ptr<Timer>> TimingData;
-
-  /// Map that counts invocations of passes, for use in UniqPassID construction.
-  StringMap<unsigned> PassIDCountMap;
+  StringMap<TimerVector> TimingData;
 
   /// Stack of currently active timers.
   SmallVector<Timer *, 8> TimerStack;
 
   /// Custom output stream to print timing information into.
   /// By default (== nullptr) we emit time report into the stream created by
   /// CreateInfoOutputFile().
   raw_ostream *OutStream = nullptr;

 
 private:
   /// Dumps information for running/triggered timers, useful for debugging
   LLVM_DUMP_METHOD void dump() const;
 
   /// Returns the new timer for each new run of the pass.
   Timer &getPassTimer(StringRef PassID);
 
-  /// Returns the incremented counter for the next invocation of \p PassID.
-  unsigned nextPassID(StringRef PassID) { return ++PassIDCountMap[PassID]; }
-
   void startTimer(StringRef PassID);
   void stopTimer(StringRef PassID);
 
   // Implementation of pass instrumentation callbacks.
   bool runBeforePass(StringRef PassID);
   void runAfterPass(StringRef PassID);
 };
 
 } // namespace llvm
 
 #endif

llvm/lib/IR/PassTimingInfo.cpp

 
 //===----------------------------------------------------------------------===//
 // Pass timing handling for the New Pass Manager
 //===----------------------------------------------------------------------===//
 
 /// Returns the timer for the specified pass invocation of \p PassID.
 /// Each time it creates a new timer.
 Timer &TimePassesHandler::getPassTimer(StringRef PassID) {
-  // Bump counts for each request of the timer.
-  unsigned Count = nextPassID(PassID);
+  // Take a vector of Timers created for this \p PassID and append
+  // one more timer to it.
+  TimerVector &Timers = TimingData[PassID];
+  unsigned Count = Timers.size() + 1;
 
-  // Unconditionally appending description with a pass-invocation number.
   std::string FullDesc = formatv("{0} #{1}", PassID, Count).str();
 
-  PassInvocationID UID{PassID, Count};
   Timer *T = new Timer(PassID, FullDesc, TG);
-  auto Pair = TimingData.try_emplace(UID, T);
-  assert(Pair.second && "should always create a new timer");
-  return *(Pair.first->second.get());
+  Timers.emplace_back(T);
+  assert(Count == Timers.size() && "sanity check");
+
+  return *T;
 }
 
 TimePassesHandler::TimePassesHandler(bool Enabled)
     : TG("pass", "... Pass execution timing report ..."), Enabled(Enabled) {}
 
 void TimePassesHandler::setOutStream(raw_ostream &Out) {
   OutStream = &Out;
 }
 
 void TimePassesHandler::print() {
   if (!Enabled)
     return;
   TG.print(OutStream ? *OutStream : *CreateInfoOutputFile(), true);
 }
 
 LLVM_DUMP_METHOD void TimePassesHandler::dump() const {
   dbgs() << "Dumping timers for " << getTypeName<TimePassesHandler>()
          << ":\n\tRunning:\n";
   for (auto &I : TimingData) {
-    const Timer *MyTimer = I.second.get();
-    if (!MyTimer || MyTimer->isRunning())
-      dbgs() << "\tTimer " << MyTimer << " for pass " << I.first.first << "("
-             << I.first.second << ")\n";
+    StringRef PassID = I.getKey();
+    const TimerVector& MyTimers = I.getValue();
+    for (unsigned idx = 0; idx < MyTimers.size(); idx++) {
+      const Timer* MyTimer = MyTimers[idx].get();
+      if (MyTimer && MyTimer->isRunning())
+        dbgs() << "\tTimer " << MyTimer << " for pass " << PassID << "(" << idx << ")\n";
+    }
   }
   dbgs() << "\tTriggered:\n";
   for (auto &I : TimingData) {
-    const Timer *MyTimer = I.second.get();
-    if (!MyTimer || (MyTimer->hasTriggered() && !MyTimer->isRunning()))
-      dbgs() << "\tTimer " << MyTimer << " for pass " << I.first.first << "("
-             << I.first.second << ")\n";
+    StringRef PassID = I.getKey();
+    const TimerVector& MyTimers = I.getValue();
+    for (unsigned idx = 0; idx < MyTimers.size(); idx++) {
+      const Timer* MyTimer = MyTimers[idx].get();
+      if (MyTimer && MyTimer->hasTriggered() && !MyTimer->isRunning())
+        dbgs() << "\tTimer " << MyTimer << " for pass " << PassID << "(" << idx << ")\n";
+    }
   }
 }
 
 void TimePassesHandler::startTimer(StringRef PassID) {
   Timer &MyTimer = getPassTimer(PassID);
   TimerStack.push_back(&MyTimer);
   if (!MyTimer.isRunning())
     MyTimer.startTimer();