Index: mlir/include/mlir/Pass/PassManager.h
===================================================================
--- mlir/include/mlir/Pass/PassManager.h
+++ mlir/include/mlir/Pass/PassManager.h
@@ -37,6 +37,7 @@
 struct OpPassManagerImpl;
 class OpToOpPassAdaptor;
 struct PassExecutionState;
+class PassTiming;
 } // end namespace detail
 
 //===----------------------------------------------------------------------===//
@@ -346,6 +347,25 @@
   /// unintentionally included in the timing results.
   void enableTiming(std::unique_ptr<PassTimingConfig> config = nullptr);
 
+  /// A helper to time code paths outside the pass manager.
+  class ExternalTimer {
+  public:
+    virtual ~ExternalTimer() {}
+
+    /// Start the timer.
+    virtual void start() = 0;
+
+    /// Stop the timer.
+    virtual void stop() = 0;
+  };
+
+  /// Get a timer that can be used to include things outside of the pass manager
+  /// in the timing statistics.
+  std::unique_ptr<ExternalTimer> getExternalTimer(Identifier name);
+  std::unique_ptr<ExternalTimer> getExternalTimer(StringRef name) {
+    return getExternalTimer(Identifier::get(name, context));
+  }
+
   /// Prompts the pass manager to print the statistics collected for each of the
   /// held passes after each call to 'run'.
   void
@@ -377,8 +397,8 @@
   /// A hash key used to detect when reinitialization is necessary.
   llvm::hash_code initializationKey;
 
-  /// Flag that specifies if pass timing is enabled.
-  bool passTiming : 1;
+  /// Pointer to the pass timing instrumentation, if it is enabled.
+  detail::PassTiming *passTiming;
 
   /// Flag that specifies if the generated crash reproducer should be local.
   bool localReproducer : 1;
Index: mlir/lib/Pass/Pass.cpp
===================================================================
--- mlir/lib/Pass/Pass.cpp
+++ mlir/lib/Pass/Pass.cpp
@@ -854,7 +854,7 @@
                          StringRef operationName)
     : OpPassManager(Identifier::get(operationName, ctx), nesting), context(ctx),
       initializationKey(DenseMapInfo<llvm::hash_code>::getTombstoneKey()),
-      passTiming(false), localReproducer(false), verifyPasses(true) {}
+      passTiming(nullptr), localReproducer(false), verifyPasses(true) {}
 
 PassManager::~PassManager() {}
 
Index: mlir/lib/Pass/PassTiming.cpp
===================================================================
--- mlir/lib/Pass/PassTiming.cpp
+++ mlir/lib/Pass/PassTiming.cpp
@@ -158,7 +158,10 @@
   /// The type of timer this instance represents.
   TimerKind kind;
 };
+} // end anonymous namespace
 
+namespace mlir {
+namespace detail {
 struct PassTiming : public PassInstrumentation {
   PassTiming(std::unique_ptr<PassManager::PassTimingConfig> config)
       : config(std::move(config)) {}
@@ -188,6 +191,12 @@
   /// Start a new timer for the given analysis.
   void startAnalysisTimer(StringRef name, TypeID id);
 
+  /// Start a new timer for the given external code path.
+  void startExternalTimer(Identifier name);
+
+  /// Stop an external timer.
+  void stopExternalTimer(Identifier name);
+
   /// Pop the last active timer for the current thread.
   Timer *popLastActiveTimer() {
     auto tid = llvm::get_threadid();
@@ -240,7 +249,8 @@
   DenseMap<PipelineParentInfo, SmallVector<Timer::ChildrenMap::value_type, 4>>
       pipelinesToMerge;
 };
-} // end anonymous namespace
+} // namespace detail
+} // namespace mlir
 
 void PassTiming::runBeforePipeline(Identifier name,
                                    const PipelineParentInfo &parentInfo) {
@@ -298,6 +308,13 @@
   timer->start();
 }
 
+/// Start a new timer for the given external code path.
+void PassTiming::startExternalTimer(Identifier name) {
+  Timer *timer = getTimer(name.getAsOpaquePointer(), TimerKind::PassOrAnalysis,
+                          [name] { return name.str(); });
+  timer->start();
+}
+
 /// Stop a pass timer.
 void PassTiming::runAfterPass(Pass *pass, Operation *) {
   Timer *timer = popLastActiveTimer();
@@ -319,6 +336,9 @@
   popLastActiveTimer()->stop();
 }
 
+/// Stop an external timer.
+void PassTiming::stopExternalTimer(Identifier) { popLastActiveTimer()->stop(); }
+
 /// Utility to print the timer heading information.
 static void printTimerHeader(raw_ostream &os, TimeRecord total) {
   os << "===" << std::string(73, '-') << "===\n";
@@ -468,6 +488,42 @@
     return;
   if (!config)
     config = std::make_unique<PassManager::PassTimingConfig>();
-  addInstrumentation(std::make_unique<PassTiming>(std::move(config)));
-  passTiming = true;
+  auto pt = std::make_unique<PassTiming>(std::move(config));
+  passTiming = pt.get();
+  addInstrumentation(std::move(pt));
+}
+
+namespace {
+/// An opaque handle for an external timer. Returned from `getExternalTimer()`
+/// to allow the caller to include code paths outside the PM in the timing
+/// statistic.
+struct ExternalTimerImpl : public PassManager::ExternalTimer {
+  PassTiming *pt;
+  Identifier name;
+  bool running = false;
+
+  ExternalTimerImpl(PassTiming *pt, Identifier name) : pt(pt), name(name) {}
+  virtual ~ExternalTimerImpl() { stop(); }
+
+  void start() override {
+    if (pt && !running) {
+      pt->startExternalTimer(name);
+      running = true;
+    }
+  }
+
+  void stop() override {
+    if (pt && running) {
+      pt->stopExternalTimer(name);
+      pt = nullptr;
+    }
+  }
+};
+} // namespace
+
+/// Get a timer that can be used to include things outside of the pass manager
+/// in the timing statistics.
+std::unique_ptr<PassManager::ExternalTimer>
+PassManager::getExternalTimer(Identifier name) {
+  return std::make_unique<ExternalTimerImpl>(passTiming, name);
 }