diff --git a/include/llvm/PassManagers.h b/include/llvm/PassManagers.h
index 94d56e4..a067294 100644
--- a/include/llvm/PassManagers.h
+++ b/include/llvm/PassManagers.h
@@ -95,6 +95,7 @@
   class Pass;
   class StringRef;
   class Value;
+  class Timer;
 
 /// FunctionPassManager and PassManager, two top level managers, serve 
 /// as the public interface of pass manager infrastructure.
@@ -460,8 +461,8 @@
   }
 };
 
-extern void StartPassTimer(llvm::Pass *);
-extern void StopPassTimer(llvm::Pass *);
+extern Timer *StartPassTimer(Pass *);
+extern void StopPassTimer(Pass *, Timer *);
 
 }
 
diff --git a/lib/Analysis/IPA/CallGraphSCCPass.cpp b/lib/Analysis/IPA/CallGraphSCCPass.cpp
index 801ae19..a96a5c5 100644
--- a/lib/Analysis/IPA/CallGraphSCCPass.cpp
+++ b/lib/Analysis/IPA/CallGraphSCCPass.cpp
@@ -96,9 +96,9 @@
       CallGraphUpToDate = true;
     }
 
-    StartPassTimer(CGSP);
+    Timer *T = StartPassTimer(CGSP);
     Changed = CGSP->runOnSCC(CurSCC);
-    StopPassTimer(CGSP);
+    StopPassTimer(CGSP, T);
     
     // After the CGSCCPass is done, when assertions are enabled, use
     // RefreshCallGraph to verify that the callgraph was correctly updated.
@@ -110,7 +110,6 @@
     return Changed;
   }
   
-  StartPassTimer(P);
   FPPassManager *FPP = dynamic_cast<FPPassManager *>(P);
   assert(FPP && "Invalid CGPassManager member");
   
@@ -118,10 +117,11 @@
   for (unsigned i = 0, e = CurSCC.size(); i != e; ++i) {
     if (Function *F = CurSCC[i]->getFunction()) {
       dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getName());
+      Timer *T = StartPassTimer(FPP);
       Changed |= FPP->runOnFunction(*F);
+      StopPassTimer(FPP, T);
     }
   }
-  StopPassTimer(P);
   
   // The function pass(es) modified the IR, they may have clobbered the
   // callgraph.
diff --git a/lib/Analysis/LoopPass.cpp b/lib/Analysis/LoopPass.cpp
index c9515f6..f3686fe 100644
--- a/lib/Analysis/LoopPass.cpp
+++ b/lib/Analysis/LoopPass.cpp
@@ -232,10 +232,10 @@
       LoopPass *LP = dynamic_cast<LoopPass *>(P);
       {
         PassManagerPrettyStackEntry X(LP, *CurrentLoop->getHeader());
-        StartPassTimer(P);
         assert(LP && "Invalid LPPassManager member");
+        Timer *T = StartPassTimer(P);
         Changed |= LP->runOnLoop(CurrentLoop, *this);
-        StopPassTimer(P);
+        StopPassTimer(P, T);
       }
 
       if (Changed)
diff --git a/lib/VMCore/PassManager.cpp b/lib/VMCore/PassManager.cpp
index 79c30aa..a3496ed 100644
--- a/lib/VMCore/PassManager.cpp
+++ b/lib/VMCore/PassManager.cpp
@@ -397,25 +397,19 @@
   // null.  It may be called multiple times.
   static void createTheTimeInfo();
 
-  void passStarted(Pass *P) {
+  /// passStarted - This method creates a timer for the given pass if it doesn't
+  /// already have one, and starts the timer.
+  Timer *passStarted(Pass *P) {
     if (dynamic_cast<PMDataManager *>(P)) 
-      return;
+      return 0;
 
     sys::SmartScopedLock<true> Lock(*TimingInfoMutex);
     std::map<Pass*, Timer>::iterator I = TimingData.find(P);
     if (I == TimingData.end())
       I=TimingData.insert(std::make_pair(P, Timer(P->getPassName(), TG))).first;
-    I->second.startTimer();
-  }
-  
-  void passEnded(Pass *P) {
-    if (dynamic_cast<PMDataManager *>(P)) 
-      return;
-
-    sys::SmartScopedLock<true> Lock(*TimingInfoMutex);
-    std::map<Pass*, Timer>::iterator I = TimingData.find(P);
-    assert(I != TimingData.end() && "passStarted/passEnded not nested right!");
-    I->second.stopTimer();
+    Timer *T = &I->second;
+    T->startTimer();
+    return T;
   }
 };
 
@@ -827,9 +821,9 @@
     // If the pass crashes releasing memory, remember this.
     PassManagerPrettyStackEntry X(P);
     
-    if (TheTimeInfo) TheTimeInfo->passStarted(P);
+    Timer *T = StartPassTimer(P);
     P->releaseMemory();
-    if (TheTimeInfo) TheTimeInfo->passEnded(P);
+    StopPassTimer(P, T);
   }
 
   if (const PassInfo *PI = P->getPassInfo()) {
@@ -1162,9 +1156,9 @@
         // If the pass crashes, remember this.
         PassManagerPrettyStackEntry X(BP, *I);
       
-        if (TheTimeInfo) TheTimeInfo->passStarted(BP);
+        Timer *T = StartPassTimer(BP);
         Changed |= BP->runOnBasicBlock(*I);
-        if (TheTimeInfo) TheTimeInfo->passEnded(BP);
+        StopPassTimer(BP, T);
       }
 
       if (Changed) 
@@ -1377,9 +1371,9 @@
     {
       PassManagerPrettyStackEntry X(FP, F);
 
-      if (TheTimeInfo) TheTimeInfo->passStarted(FP);
+      Timer *T = StartPassTimer(FP);
       Changed |= FP->runOnFunction(F);
-      if (TheTimeInfo) TheTimeInfo->passEnded(FP);
+      StopPassTimer(FP, T);
     }
 
     if (Changed) 
@@ -1453,9 +1447,9 @@
 
     {
       PassManagerPrettyStackEntry X(MP, M);
-      if (TheTimeInfo) TheTimeInfo->passStarted(MP);
+      Timer *T = StartPassTimer(MP);
       Changed |= MP->runOnModule(M);
-      if (TheTimeInfo) TheTimeInfo->passEnded(MP);
+      StopPassTimer(MP, T);
     }
 
     if (Changed) 
@@ -1591,15 +1585,15 @@
 }
 
 /// If TimingInfo is enabled then start pass timer.
-void llvm::StartPassTimer(Pass *P) {
+Timer *llvm::StartPassTimer(Pass *P) {
   if (TheTimeInfo) 
-    TheTimeInfo->passStarted(P);
+    return TheTimeInfo->passStarted(P);
+  return 0;
 }
 
 /// If TimingInfo is enabled then stop pass timer.
-void llvm::StopPassTimer(Pass *P) {
-  if (TheTimeInfo) 
-    TheTimeInfo->passEnded(P);
+void llvm::StopPassTimer(Pass *P, Timer *T) {
+  if (T) T->stopTimer();
 }
 
 //===----------------------------------------------------------------------===//