Index: llvm/lib/Passes/StandardInstrumentations.cpp
===================================================================
--- llvm/lib/Passes/StandardInstrumentations.cpp
+++ llvm/lib/Passes/StandardInstrumentations.cpp
@@ -241,7 +241,13 @@
   }
 
   // Determine if this pass/IR is interesting and if so, save the IR
+  // otherwise it is left on the stack without data
   void saveIRBeforePass(Any IR, StringRef PassID) {
+    // Always need to place something on the stack because invalidated passes
+    // are not given the IR so it cannot be determined whether the pass was for
+    // something that was filtered out.
+    BeforeStack.emplace_back();
+
     if (!isInteresting(IR, PassID))
       return;
     // Is this the initial IR?
@@ -251,12 +257,12 @@
     }
 
     // Save the IR representation on the stack.
-    BeforeStack.emplace_back();
     auto &Data = BeforeStack.back();
     GenerateIRRepresentation(IR, PassID, Data);
   }
   // Compare the IR from before the pass after the pass.
   void handleIRAfterPass(Any IR, StringRef PassID) {
+    assert(!BeforeStack.empty() && "Unexpected empty stack encountered.");
     std::string Name;
 
     // unwrapModule has inconsistent handling of names for function IRs.
@@ -270,36 +276,33 @@
     if (Name == "")
       Name = " (module)";
 
-    if (isIgnored(PassID)) {
+    if (isIgnored(PassID))
       HandleIgnored(PassID, Name);
-      return;
-    }
-
-    if (!isInteresting(IR, PassID)) {
+    else if (!isInteresting(IR, PassID))
       HandleFiltered(PassID, Name);
-      return;
+    else {
+      // Get the before rep from the stack
+      T &Before = BeforeStack.back();
+      // Create the after rep
+      T After;
+      GenerateIRRepresentation(IR, PassID, After);
+
+      // was there a change in IR?
+      if (Same(Before, After))
+        OmitAfter(PassID, Name);
+      else
+        HandleAfter(Name, PassID, Before, After, IR);
     }
-
-    assert(!BeforeStack.empty() && "Unexpected empty stack for printing.");
-
-    // Get the before rep from the stack
-    T &Before = BeforeStack.back();
-    // Create the after rep
-    T After;
-    GenerateIRRepresentation(IR, PassID, After);
-
-    // was there a change in IR?
-    if (Same(Before, After))
-      OmitAfter(PassID, Name);
-    else
-      HandleAfter(Name, PassID, Before, After, IR);
-
-    // Now remove the before IR as it is no longer needed.
     BeforeStack.pop_back();
   }
   // Handle the situation where a pass is invalidated.
   void handleInvalidatedPass(StringRef PassID) {
-    assert(!BeforeStack.empty() && "Unexpected empty stack for printing.");
+    assert(!BeforeStack.empty() && "Unexpected empty stack encountered.");
+
+    // Always flag it as invalidated as we cannot determine when
+    // a pass for a filtered function is invalidated since we do not
+    // get the IR in the callback.  Also, the output is just alternate
+    // forms of the banner anyway.
     HandleInvalidated(PassID);
     BeforeStack.pop_back();
   }
@@ -458,7 +461,10 @@
 
 void registerChangePrinters(PassInstrumentationCallbacks &PIC) {
   if (PrintChanged) {
+    // Must be static as lifespan is across multiple callbacks.
+    // N.B. this may cause problems if the compiler becomes multi-threaded.
     static IRChangePrinter ICP(dbgs());
+
     PIC.registerBeforePassCallback([](StringRef P, Any IR) {
       ICP.saveIRBeforePass(IR, P);
       return true;