diff --git a/llvm/include/llvm/Passes/PassBuilder.h b/llvm/include/llvm/Passes/PassBuilder.h
index b0703457656b21..5adbd5ca76c7b9 100644
--- a/llvm/include/llvm/Passes/PassBuilder.h
+++ b/llvm/include/llvm/Passes/PassBuilder.h
@@ -488,7 +488,6 @@ class PassBuilder {
   /// preferred when a pipeline is largely of one type, but one or just a few
   /// passes are of different types(See PassBuilder.cpp for examples).
   Error parsePassPipeline(ModulePassManager &MPM, StringRef PipelineText,
-                          bool VerifyEachPass = true,
                           bool DebugLogging = false);
 
   /// {{@ Parse a textual pass pipeline description into a specific PassManager
@@ -499,13 +498,10 @@ class PassBuilder {
   ///
   ///   function(lpass)
   Error parsePassPipeline(CGSCCPassManager &CGPM, StringRef PipelineText,
-                          bool VerifyEachPass = true,
                           bool DebugLogging = false);
   Error parsePassPipeline(FunctionPassManager &FPM, StringRef PipelineText,
-                          bool VerifyEachPass = true,
                           bool DebugLogging = false);
   Error parsePassPipeline(LoopPassManager &LPM, StringRef PipelineText,
-                          bool VerifyEachPass = true,
                           bool DebugLogging = false);
   /// @}}
 
@@ -682,10 +678,46 @@ class PassBuilder {
   /// PassManagers and populate the passed ModulePassManager.
   void registerParseTopLevelPipelineCallback(
       const std::function<bool(ModulePassManager &, ArrayRef<PipelineElement>,
-                               bool VerifyEachPass, bool DebugLogging)> &C) {
+                               bool DebugLogging)> &C) {
     TopLevelPipelineParsingCallbacks.push_back(C);
   }
 
+  /// {{@ Register callbacks for before/after parsing passes.
+  /// For example, to add a verifier pass after each parsed pass.
+  void registerBeforeParsingModulePassCallback(
+      const std::function<void(ModulePassManager &)> &C) {
+    ModulePassBeforeParsingCallbacks.push_back(C);
+  }
+  void registerBeforeParsingCGSCCPassCallback(
+      const std::function<void(CGSCCPassManager &)> &C) {
+    CGSCCPassBeforeParsingCallbacks.push_back(C);
+  }
+  void registerBeforeParsingFunctionPassCallback(
+      const std::function<void(FunctionPassManager &)> &C) {
+    FunctionPassBeforeParsingCallbacks.push_back(C);
+  }
+  void registerBeforeParsingLoopPassCallback(
+      const std::function<void(LoopPassManager &)> &C) {
+    LoopPassBeforeParsingCallbacks.push_back(C);
+  }
+  void registerAfterParsingModulePassCallback(
+      const std::function<void(ModulePassManager &)> &C) {
+    ModulePassAfterParsingCallbacks.push_back(C);
+  }
+  void registerAfterParsingCGSCCPassCallback(
+      const std::function<void(CGSCCPassManager &)> &C) {
+    CGSCCPassAfterParsingCallbacks.push_back(C);
+  }
+  void registerAfterParsingFunctionPassCallback(
+      const std::function<void(FunctionPassManager &)> &C) {
+    FunctionPassAfterParsingCallbacks.push_back(C);
+  }
+  void registerAfterParsingLoopPassCallback(
+      const std::function<void(LoopPassManager &)> &C) {
+    LoopPassAfterParsingCallbacks.push_back(C);
+  }
+  /// @}}
+
   /// Add PGOInstrumenation passes for O0 only.
   void addPGOInstrPassesForO0(ModulePassManager &MPM, bool DebugLogging,
                               bool RunProfileGen, bool IsCS,
@@ -708,27 +740,27 @@ class PassBuilder {
   parsePipelineText(StringRef Text);
 
   Error parseModulePass(ModulePassManager &MPM, const PipelineElement &E,
-                        bool VerifyEachPass, bool DebugLogging);
+                        bool DebugLogging);
   Error parseCGSCCPass(CGSCCPassManager &CGPM, const PipelineElement &E,
-                       bool VerifyEachPass, bool DebugLogging);
+                       bool DebugLogging);
   Error parseFunctionPass(FunctionPassManager &FPM, const PipelineElement &E,
-                          bool VerifyEachPass, bool DebugLogging);
+                          bool DebugLogging);
   Error parseLoopPass(LoopPassManager &LPM, const PipelineElement &E,
-                      bool VerifyEachPass, bool DebugLogging);
+                      bool DebugLogging);
   bool parseAAPassName(AAManager &AA, StringRef Name);
 
   Error parseLoopPassPipeline(LoopPassManager &LPM,
                               ArrayRef<PipelineElement> Pipeline,
-                              bool VerifyEachPass, bool DebugLogging);
+                              bool DebugLogging);
   Error parseFunctionPassPipeline(FunctionPassManager &FPM,
                                   ArrayRef<PipelineElement> Pipeline,
-                                  bool VerifyEachPass, bool DebugLogging);
+                                  bool DebugLogging);
   Error parseCGSCCPassPipeline(CGSCCPassManager &CGPM,
                                ArrayRef<PipelineElement> Pipeline,
-                               bool VerifyEachPass, bool DebugLogging);
+                               bool DebugLogging);
   Error parseModulePassPipeline(ModulePassManager &MPM,
                                 ArrayRef<PipelineElement> Pipeline,
-                                bool VerifyEachPass, bool DebugLogging);
+                                bool DebugLogging);
 
   void addPGOInstrPasses(ModulePassManager &MPM, bool DebugLogging,
                          OptimizationLevel Level, bool RunProfileGen, bool IsCS,
@@ -761,7 +793,7 @@ class PassBuilder {
               2>
       ModulePipelineParsingCallbacks;
   SmallVector<std::function<bool(ModulePassManager &, ArrayRef<PipelineElement>,
-                                 bool VerifyEachPass, bool DebugLogging)>,
+                                 bool DebugLogging)>,
               2>
       TopLevelPipelineParsingCallbacks;
   // CGSCC callbacks
@@ -788,6 +820,23 @@ class PassBuilder {
   // AA callbacks
   SmallVector<std::function<bool(StringRef Name, AAManager &AA)>, 2>
       AAParsingCallbacks;
+  // Before/after pass parsing callbacks
+  SmallVector<std::function<void(ModulePassManager &)>, 2>
+      ModulePassBeforeParsingCallbacks;
+  SmallVector<std::function<void(ModulePassManager &)>, 2>
+      ModulePassAfterParsingCallbacks;
+  SmallVector<std::function<void(CGSCCPassManager &)>, 2>
+      CGSCCPassBeforeParsingCallbacks;
+  SmallVector<std::function<void(CGSCCPassManager &)>, 2>
+      CGSCCPassAfterParsingCallbacks;
+  SmallVector<std::function<void(FunctionPassManager &)>, 2>
+      FunctionPassBeforeParsingCallbacks;
+  SmallVector<std::function<void(FunctionPassManager &)>, 2>
+      FunctionPassAfterParsingCallbacks;
+  SmallVector<std::function<void(LoopPassManager &)>, 2>
+      LoopPassBeforeParsingCallbacks;
+  SmallVector<std::function<void(LoopPassManager &)>, 2>
+      LoopPassAfterParsingCallbacks;
 };
 
 /// This utility template takes care of adding require<> and invalidate<>
diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index 8dfeb158bf1279..a1f8e998c58a19 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -2115,7 +2115,7 @@ PassBuilder::parsePipelineText(StringRef Text) {
 
 Error PassBuilder::parseModulePass(ModulePassManager &MPM,
                                    const PipelineElement &E,
-                                   bool VerifyEachPass, bool DebugLogging) {
+                                   bool DebugLogging) {
   auto &Name = E.Name;
   auto &InnerPipeline = E.InnerPipeline;
 
@@ -2123,32 +2123,31 @@ Error PassBuilder::parseModulePass(ModulePassManager &MPM,
   if (!InnerPipeline.empty()) {
     if (Name == "module") {
       ModulePassManager NestedMPM(DebugLogging);
-      if (auto Err = parseModulePassPipeline(NestedMPM, InnerPipeline,
-                                             VerifyEachPass, DebugLogging))
+      if (auto Err =
+              parseModulePassPipeline(NestedMPM, InnerPipeline, DebugLogging))
         return Err;
       MPM.addPass(std::move(NestedMPM));
       return Error::success();
     }
     if (Name == "cgscc") {
       CGSCCPassManager CGPM(DebugLogging);
-      if (auto Err = parseCGSCCPassPipeline(CGPM, InnerPipeline, VerifyEachPass,
-                                            DebugLogging))
+      if (auto Err = parseCGSCCPassPipeline(CGPM, InnerPipeline, DebugLogging))
         return Err;
       MPM.addPass(createModuleToPostOrderCGSCCPassAdaptor(std::move(CGPM)));
       return Error::success();
     }
     if (Name == "function") {
       FunctionPassManager FPM(DebugLogging);
-      if (auto Err = parseFunctionPassPipeline(FPM, InnerPipeline,
-                                               VerifyEachPass, DebugLogging))
+      if (auto Err =
+              parseFunctionPassPipeline(FPM, InnerPipeline, DebugLogging))
         return Err;
       MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
       return Error::success();
     }
     if (auto Count = parseRepeatPassName(Name)) {
       ModulePassManager NestedMPM(DebugLogging);
-      if (auto Err = parseModulePassPipeline(NestedMPM, InnerPipeline,
-                                             VerifyEachPass, DebugLogging))
+      if (auto Err =
+              parseModulePassPipeline(NestedMPM, InnerPipeline, DebugLogging))
         return Err;
       MPM.addPass(createRepeatedPass(*Count, std::move(NestedMPM)));
       return Error::success();
@@ -2297,8 +2296,7 @@ Error PassBuilder::parseModulePass(ModulePassManager &MPM,
 }
 
 Error PassBuilder::parseCGSCCPass(CGSCCPassManager &CGPM,
-                                  const PipelineElement &E, bool VerifyEachPass,
-                                  bool DebugLogging) {
+                                  const PipelineElement &E, bool DebugLogging) {
   auto &Name = E.Name;
   auto &InnerPipeline = E.InnerPipeline;
 
@@ -2306,8 +2304,8 @@ Error PassBuilder::parseCGSCCPass(CGSCCPassManager &CGPM,
   if (!InnerPipeline.empty()) {
     if (Name == "cgscc") {
       CGSCCPassManager NestedCGPM(DebugLogging);
-      if (auto Err = parseCGSCCPassPipeline(NestedCGPM, InnerPipeline,
-                                            VerifyEachPass, DebugLogging))
+      if (auto Err =
+              parseCGSCCPassPipeline(NestedCGPM, InnerPipeline, DebugLogging))
         return Err;
       // Add the nested pass manager with the appropriate adaptor.
       CGPM.addPass(std::move(NestedCGPM));
@@ -2315,8 +2313,8 @@ Error PassBuilder::parseCGSCCPass(CGSCCPassManager &CGPM,
     }
     if (Name == "function") {
       FunctionPassManager FPM(DebugLogging);
-      if (auto Err = parseFunctionPassPipeline(FPM, InnerPipeline,
-                                               VerifyEachPass, DebugLogging))
+      if (auto Err =
+              parseFunctionPassPipeline(FPM, InnerPipeline, DebugLogging))
         return Err;
       // Add the nested pass manager with the appropriate adaptor.
       CGPM.addPass(createCGSCCToFunctionPassAdaptor(std::move(FPM)));
@@ -2324,16 +2322,16 @@ Error PassBuilder::parseCGSCCPass(CGSCCPassManager &CGPM,
     }
     if (auto Count = parseRepeatPassName(Name)) {
       CGSCCPassManager NestedCGPM(DebugLogging);
-      if (auto Err = parseCGSCCPassPipeline(NestedCGPM, InnerPipeline,
-                                            VerifyEachPass, DebugLogging))
+      if (auto Err =
+              parseCGSCCPassPipeline(NestedCGPM, InnerPipeline, DebugLogging))
         return Err;
       CGPM.addPass(createRepeatedPass(*Count, std::move(NestedCGPM)));
       return Error::success();
     }
     if (auto MaxRepetitions = parseDevirtPassName(Name)) {
       CGSCCPassManager NestedCGPM(DebugLogging);
-      if (auto Err = parseCGSCCPassPipeline(NestedCGPM, InnerPipeline,
-                                            VerifyEachPass, DebugLogging))
+      if (auto Err =
+              parseCGSCCPassPipeline(NestedCGPM, InnerPipeline, DebugLogging))
         return Err;
       CGPM.addPass(
           createDevirtSCCRepeatedPass(std::move(NestedCGPM), *MaxRepetitions));
@@ -2411,7 +2409,7 @@ Error PassBuilder::parseCGSCCPass(CGSCCPassManager &CGPM,
 
 Error PassBuilder::parseFunctionPass(FunctionPassManager &FPM,
                                      const PipelineElement &E,
-                                     bool VerifyEachPass, bool DebugLogging) {
+                                     bool DebugLogging) {
   auto &Name = E.Name;
   auto &InnerPipeline = E.InnerPipeline;
 
@@ -2419,8 +2417,8 @@ Error PassBuilder::parseFunctionPass(FunctionPassManager &FPM,
   if (!InnerPipeline.empty()) {
     if (Name == "function") {
       FunctionPassManager NestedFPM(DebugLogging);
-      if (auto Err = parseFunctionPassPipeline(NestedFPM, InnerPipeline,
-                                               VerifyEachPass, DebugLogging))
+      if (auto Err =
+              parseFunctionPassPipeline(NestedFPM, InnerPipeline, DebugLogging))
         return Err;
       // Add the nested pass manager with the appropriate adaptor.
       FPM.addPass(std::move(NestedFPM));
@@ -2428,8 +2426,7 @@ Error PassBuilder::parseFunctionPass(FunctionPassManager &FPM,
     }
     if (Name == "loop" || Name == "loop-mssa") {
       LoopPassManager LPM(DebugLogging);
-      if (auto Err = parseLoopPassPipeline(LPM, InnerPipeline, VerifyEachPass,
-                                           DebugLogging))
+      if (auto Err = parseLoopPassPipeline(LPM, InnerPipeline, DebugLogging))
         return Err;
       // Add the nested pass manager with the appropriate adaptor.
       bool UseMemorySSA = (Name == "loop-mssa");
@@ -2442,8 +2439,8 @@ Error PassBuilder::parseFunctionPass(FunctionPassManager &FPM,
     }
     if (auto Count = parseRepeatPassName(Name)) {
       FunctionPassManager NestedFPM(DebugLogging);
-      if (auto Err = parseFunctionPassPipeline(NestedFPM, InnerPipeline,
-                                               VerifyEachPass, DebugLogging))
+      if (auto Err =
+              parseFunctionPassPipeline(NestedFPM, InnerPipeline, DebugLogging))
         return Err;
       FPM.addPass(createRepeatedPass(*Count, std::move(NestedFPM)));
       return Error::success();
@@ -2515,7 +2512,7 @@ Error PassBuilder::parseFunctionPass(FunctionPassManager &FPM,
 }
 
 Error PassBuilder::parseLoopPass(LoopPassManager &LPM, const PipelineElement &E,
-                                 bool VerifyEachPass, bool DebugLogging) {
+                                 bool DebugLogging) {
   StringRef Name = E.Name;
   auto &InnerPipeline = E.InnerPipeline;
 
@@ -2523,8 +2520,8 @@ Error PassBuilder::parseLoopPass(LoopPassManager &LPM, const PipelineElement &E,
   if (!InnerPipeline.empty()) {
     if (Name == "loop") {
       LoopPassManager NestedLPM(DebugLogging);
-      if (auto Err = parseLoopPassPipeline(NestedLPM, InnerPipeline,
-                                           VerifyEachPass, DebugLogging))
+      if (auto Err =
+              parseLoopPassPipeline(NestedLPM, InnerPipeline, DebugLogging))
         return Err;
       // Add the nested pass manager with the appropriate adaptor.
       LPM.addPass(std::move(NestedLPM));
@@ -2532,8 +2529,8 @@ Error PassBuilder::parseLoopPass(LoopPassManager &LPM, const PipelineElement &E,
     }
     if (auto Count = parseRepeatPassName(Name)) {
       LoopPassManager NestedLPM(DebugLogging);
-      if (auto Err = parseLoopPassPipeline(NestedLPM, InnerPipeline,
-                                           VerifyEachPass, DebugLogging))
+      if (auto Err =
+              parseLoopPassPipeline(NestedLPM, InnerPipeline, DebugLogging))
         return Err;
       LPM.addPass(createRepeatedPass(*Count, std::move(NestedLPM)));
       return Error::success();
@@ -2608,38 +2605,42 @@ bool PassBuilder::parseAAPassName(AAManager &AA, StringRef Name) {
 
 Error PassBuilder::parseLoopPassPipeline(LoopPassManager &LPM,
                                          ArrayRef<PipelineElement> Pipeline,
-                                         bool VerifyEachPass,
                                          bool DebugLogging) {
   for (const auto &Element : Pipeline) {
-    if (auto Err = parseLoopPass(LPM, Element, VerifyEachPass, DebugLogging))
+    for (auto &C : LoopPassBeforeParsingCallbacks)
+      C(LPM);
+    if (auto Err = parseLoopPass(LPM, Element, DebugLogging))
       return Err;
-    // FIXME: No verifier support for Loop passes!
+    for (auto &C : LoopPassAfterParsingCallbacks)
+      C(LPM);
   }
   return Error::success();
 }
 
 Error PassBuilder::parseFunctionPassPipeline(FunctionPassManager &FPM,
                                              ArrayRef<PipelineElement> Pipeline,
-                                             bool VerifyEachPass,
                                              bool DebugLogging) {
   for (const auto &Element : Pipeline) {
-    if (auto Err =
-            parseFunctionPass(FPM, Element, VerifyEachPass, DebugLogging))
+    for (auto &C : FunctionPassBeforeParsingCallbacks)
+      C(FPM);
+    if (auto Err = parseFunctionPass(FPM, Element, DebugLogging))
       return Err;
-    if (VerifyEachPass)
-      FPM.addPass(VerifierPass());
+    for (auto &C : FunctionPassAfterParsingCallbacks)
+      C(FPM);
   }
   return Error::success();
 }
 
 Error PassBuilder::parseCGSCCPassPipeline(CGSCCPassManager &CGPM,
                                           ArrayRef<PipelineElement> Pipeline,
-                                          bool VerifyEachPass,
                                           bool DebugLogging) {
   for (const auto &Element : Pipeline) {
-    if (auto Err = parseCGSCCPass(CGPM, Element, VerifyEachPass, DebugLogging))
+    for (auto &C : CGSCCPassBeforeParsingCallbacks)
+      C(CGPM);
+    if (auto Err = parseCGSCCPass(CGPM, Element, DebugLogging))
       return Err;
-    // FIXME: No verifier support for CGSCC passes!
+    for (auto &C : CGSCCPassAfterParsingCallbacks)
+      C(CGPM);
   }
   return Error::success();
 }
@@ -2659,13 +2660,14 @@ void PassBuilder::crossRegisterProxies(LoopAnalysisManager &LAM,
 
 Error PassBuilder::parseModulePassPipeline(ModulePassManager &MPM,
                                            ArrayRef<PipelineElement> Pipeline,
-                                           bool VerifyEachPass,
                                            bool DebugLogging) {
   for (const auto &Element : Pipeline) {
-    if (auto Err = parseModulePass(MPM, Element, VerifyEachPass, DebugLogging))
+    for (auto &C : ModulePassBeforeParsingCallbacks)
+      C(MPM);
+    if (auto Err = parseModulePass(MPM, Element, DebugLogging))
       return Err;
-    if (VerifyEachPass)
-      MPM.addPass(VerifierPass());
+    for (auto &C : ModulePassAfterParsingCallbacks)
+      C(MPM);
   }
   return Error::success();
 }
@@ -2675,7 +2677,7 @@ Error PassBuilder::parseModulePassPipeline(ModulePassManager &MPM,
 // pre-populate the analysis managers with target-specific stuff?
 Error PassBuilder::parsePassPipeline(ModulePassManager &MPM,
                                      StringRef PipelineText,
-                                     bool VerifyEachPass, bool DebugLogging) {
+                                     bool DebugLogging) {
   auto Pipeline = parsePipelineText(PipelineText);
   if (!Pipeline || Pipeline->empty())
     return make_error<StringError>(
@@ -2696,7 +2698,7 @@ Error PassBuilder::parsePassPipeline(ModulePassManager &MPM,
       Pipeline = {{"function", {{"loop", std::move(*Pipeline)}}}};
     } else {
       for (auto &C : TopLevelPipelineParsingCallbacks)
-        if (C(MPM, *Pipeline, VerifyEachPass, DebugLogging))
+        if (C(MPM, *Pipeline, DebugLogging))
           return Error::success();
 
       // Unknown pass or pipeline name!
@@ -2709,8 +2711,7 @@ Error PassBuilder::parsePassPipeline(ModulePassManager &MPM,
     }
   }
 
-  if (auto Err =
-          parseModulePassPipeline(MPM, *Pipeline, VerifyEachPass, DebugLogging))
+  if (auto Err = parseModulePassPipeline(MPM, *Pipeline, DebugLogging))
     return Err;
   return Error::success();
 }
@@ -2718,7 +2719,7 @@ Error PassBuilder::parsePassPipeline(ModulePassManager &MPM,
 // Primary pass pipeline description parsing routine for a \c CGSCCPassManager
 Error PassBuilder::parsePassPipeline(CGSCCPassManager &CGPM,
                                      StringRef PipelineText,
-                                     bool VerifyEachPass, bool DebugLogging) {
+                                     bool DebugLogging) {
   auto Pipeline = parsePipelineText(PipelineText);
   if (!Pipeline || Pipeline->empty())
     return make_error<StringError>(
@@ -2733,8 +2734,7 @@ Error PassBuilder::parsePassPipeline(CGSCCPassManager &CGPM,
             .str(),
         inconvertibleErrorCode());
 
-  if (auto Err =
-          parseCGSCCPassPipeline(CGPM, *Pipeline, VerifyEachPass, DebugLogging))
+  if (auto Err = parseCGSCCPassPipeline(CGPM, *Pipeline, DebugLogging))
     return Err;
   return Error::success();
 }
@@ -2743,7 +2743,7 @@ Error PassBuilder::parsePassPipeline(CGSCCPassManager &CGPM,
 // FunctionPassManager
 Error PassBuilder::parsePassPipeline(FunctionPassManager &FPM,
                                      StringRef PipelineText,
-                                     bool VerifyEachPass, bool DebugLogging) {
+                                     bool DebugLogging) {
   auto Pipeline = parsePipelineText(PipelineText);
   if (!Pipeline || Pipeline->empty())
     return make_error<StringError>(
@@ -2758,8 +2758,7 @@ Error PassBuilder::parsePassPipeline(FunctionPassManager &FPM,
             .str(),
         inconvertibleErrorCode());
 
-  if (auto Err = parseFunctionPassPipeline(FPM, *Pipeline, VerifyEachPass,
-                                           DebugLogging))
+  if (auto Err = parseFunctionPassPipeline(FPM, *Pipeline, DebugLogging))
     return Err;
   return Error::success();
 }
@@ -2767,15 +2766,14 @@ Error PassBuilder::parsePassPipeline(FunctionPassManager &FPM,
 // Primary pass pipeline description parsing routine for a \c LoopPassManager
 Error PassBuilder::parsePassPipeline(LoopPassManager &CGPM,
                                      StringRef PipelineText,
-                                     bool VerifyEachPass, bool DebugLogging) {
+                                     bool DebugLogging) {
   auto Pipeline = parsePipelineText(PipelineText);
   if (!Pipeline || Pipeline->empty())
     return make_error<StringError>(
         formatv("invalid pipeline '{0}'", PipelineText).str(),
         inconvertibleErrorCode());
 
-  if (auto Err =
-          parseLoopPassPipeline(CGPM, *Pipeline, VerifyEachPass, DebugLogging))
+  if (auto Err = parseLoopPassPipeline(CGPM, *Pipeline, DebugLogging))
     return Err;
 
   return Error::success();
diff --git a/llvm/tools/llvm-opt-fuzzer/llvm-opt-fuzzer.cpp b/llvm/tools/llvm-opt-fuzzer/llvm-opt-fuzzer.cpp
index 4c672bc2a3bd41..40aac7c3a2814a 100644
--- a/llvm/tools/llvm-opt-fuzzer/llvm-opt-fuzzer.cpp
+++ b/llvm/tools/llvm-opt-fuzzer/llvm-opt-fuzzer.cpp
@@ -148,7 +148,7 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) {
   PB.registerLoopAnalyses(LAM);
   PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
 
-  auto Err = PB.parsePassPipeline(MPM, PassPipeline, false, false);
+  auto Err = PB.parsePassPipeline(MPM, PassPipeline, false);
   assert(!Err && "Should have been checked during fuzzer initialization");
   // Only fail with assert above, otherwise ignore the parsing error.
   consumeError(std::move(Err));
@@ -241,7 +241,7 @@ extern "C" LLVM_ATTRIBUTE_USED int LLVMFuzzerInitialize(
 
   PassBuilder PB(TM.get());
   ModulePassManager MPM;
-  if (auto Err = PB.parsePassPipeline(MPM, PassPipeline, false, false)) {
+  if (auto Err = PB.parsePassPipeline(MPM, PassPipeline, false)) {
     errs() << *argv[0] << ": " << toString(std::move(Err)) << "\n";
     exit(1);
   }
diff --git a/llvm/tools/opt/NewPMDriver.cpp b/llvm/tools/opt/NewPMDriver.cpp
index c6c4191c14592e..ae97877d3adad7 100644
--- a/llvm/tools/opt/NewPMDriver.cpp
+++ b/llvm/tools/opt/NewPMDriver.cpp
@@ -140,72 +140,68 @@ bool tryParsePipelineText(PassBuilder &PB,
 
 /// If one of the EPPipeline command line options was given, register callbacks
 /// for parsing and inserting the given pipeline
-static void registerEPCallbacks(PassBuilder &PB, bool VerifyEachPass,
-                                bool DebugLogging) {
+static void registerEPCallbacks(PassBuilder &PB, bool DebugLogging) {
   if (tryParsePipelineText<FunctionPassManager>(PB, PeepholeEPPipeline))
     PB.registerPeepholeEPCallback(
-        [&PB, VerifyEachPass, DebugLogging](
-            FunctionPassManager &PM, PassBuilder::OptimizationLevel Level) {
+        [&PB, DebugLogging](FunctionPassManager &PM,
+                            PassBuilder::OptimizationLevel Level) {
           ExitOnError Err("Unable to parse PeepholeEP pipeline: ");
-          Err(PB.parsePassPipeline(PM, PeepholeEPPipeline, VerifyEachPass,
-                                   DebugLogging));
+          Err(PB.parsePassPipeline(PM, PeepholeEPPipeline, DebugLogging));
         });
   if (tryParsePipelineText<LoopPassManager>(PB,
                                             LateLoopOptimizationsEPPipeline))
     PB.registerLateLoopOptimizationsEPCallback(
-        [&PB, VerifyEachPass, DebugLogging](
-            LoopPassManager &PM, PassBuilder::OptimizationLevel Level) {
+        [&PB, DebugLogging](LoopPassManager &PM,
+                            PassBuilder::OptimizationLevel Level) {
           ExitOnError Err("Unable to parse LateLoopOptimizationsEP pipeline: ");
           Err(PB.parsePassPipeline(PM, LateLoopOptimizationsEPPipeline,
-                                   VerifyEachPass, DebugLogging));
+                                   DebugLogging));
         });
   if (tryParsePipelineText<LoopPassManager>(PB, LoopOptimizerEndEPPipeline))
     PB.registerLoopOptimizerEndEPCallback(
-        [&PB, VerifyEachPass, DebugLogging](
-            LoopPassManager &PM, PassBuilder::OptimizationLevel Level) {
+        [&PB, DebugLogging](LoopPassManager &PM,
+                            PassBuilder::OptimizationLevel Level) {
           ExitOnError Err("Unable to parse LoopOptimizerEndEP pipeline: ");
           Err(PB.parsePassPipeline(PM, LoopOptimizerEndEPPipeline,
-                                   VerifyEachPass, DebugLogging));
+                                   DebugLogging));
         });
   if (tryParsePipelineText<FunctionPassManager>(PB,
                                                 ScalarOptimizerLateEPPipeline))
     PB.registerScalarOptimizerLateEPCallback(
-        [&PB, VerifyEachPass, DebugLogging](
-            FunctionPassManager &PM, PassBuilder::OptimizationLevel Level) {
+        [&PB, DebugLogging](FunctionPassManager &PM,
+                            PassBuilder::OptimizationLevel Level) {
           ExitOnError Err("Unable to parse ScalarOptimizerLateEP pipeline: ");
           Err(PB.parsePassPipeline(PM, ScalarOptimizerLateEPPipeline,
-                                   VerifyEachPass, DebugLogging));
+                                   DebugLogging));
         });
   if (tryParsePipelineText<CGSCCPassManager>(PB, CGSCCOptimizerLateEPPipeline))
     PB.registerCGSCCOptimizerLateEPCallback(
-        [&PB, VerifyEachPass, DebugLogging](
-            CGSCCPassManager &PM, PassBuilder::OptimizationLevel Level) {
+        [&PB, DebugLogging](CGSCCPassManager &PM,
+                            PassBuilder::OptimizationLevel Level) {
           ExitOnError Err("Unable to parse CGSCCOptimizerLateEP pipeline: ");
           Err(PB.parsePassPipeline(PM, CGSCCOptimizerLateEPPipeline,
-                                   VerifyEachPass, DebugLogging));
+                                   DebugLogging));
         });
   if (tryParsePipelineText<FunctionPassManager>(PB, VectorizerStartEPPipeline))
     PB.registerVectorizerStartEPCallback(
-        [&PB, VerifyEachPass, DebugLogging](
-            FunctionPassManager &PM, PassBuilder::OptimizationLevel Level) {
+        [&PB, DebugLogging](FunctionPassManager &PM,
+                            PassBuilder::OptimizationLevel Level) {
           ExitOnError Err("Unable to parse VectorizerStartEP pipeline: ");
           Err(PB.parsePassPipeline(PM, VectorizerStartEPPipeline,
-                                   VerifyEachPass, DebugLogging));
+                                   DebugLogging));
         });
   if (tryParsePipelineText<ModulePassManager>(PB, PipelineStartEPPipeline))
     PB.registerPipelineStartEPCallback(
-        [&PB, VerifyEachPass, DebugLogging](ModulePassManager &PM) {
+        [&PB, DebugLogging](ModulePassManager &PM) {
           ExitOnError Err("Unable to parse PipelineStartEP pipeline: ");
-          Err(PB.parsePassPipeline(PM, PipelineStartEPPipeline, VerifyEachPass,
-                                   DebugLogging));
+          Err(PB.parsePassPipeline(PM, PipelineStartEPPipeline, DebugLogging));
         });
   if (tryParsePipelineText<FunctionPassManager>(PB, OptimizerLastEPPipeline))
     PB.registerOptimizerLastEPCallback(
-        [&PB, VerifyEachPass, DebugLogging](ModulePassManager &PM,
-                                            PassBuilder::OptimizationLevel) {
+        [&PB, DebugLogging](ModulePassManager &PM,
+                            PassBuilder::OptimizationLevel) {
           ExitOnError Err("Unable to parse OptimizerLastEP pipeline: ");
-          Err(PB.parsePassPipeline(PM, OptimizerLastEPPipeline, VerifyEachPass,
-                                   DebugLogging));
+          Err(PB.parsePassPipeline(PM, OptimizerLastEPPipeline, DebugLogging));
         });
 }
 
@@ -274,7 +270,15 @@ bool llvm::runPassPipeline(StringRef Arg0, Module &M, TargetMachine *TM,
   PTO.LoopUnrolling = !DisableLoopUnrolling;
   PTO.Coroutines = Coroutines;
   PassBuilder PB(TM, PTO, P, &PIC);
-  registerEPCallbacks(PB, VerifyEachPass, DebugPM);
+  registerEPCallbacks(PB, DebugPM);
+
+  if (VerifyEachPass) {
+    // No verifier support for CGSCC/Loop passes.
+    PB.registerAfterParsingFunctionPassCallback(
+        [](FunctionPassManager &FPM) { FPM.addPass(VerifierPass()); });
+    PB.registerAfterParsingModulePassCallback(
+        [](ModulePassManager &MPM) { MPM.addPass(VerifierPass()); });
+  }
 
   // Load requested pass plugins and let them register pass builder callbacks
   for (auto &PluginFN : PassPlugins) {
@@ -384,8 +388,7 @@ bool llvm::runPassPipeline(StringRef Arg0, Module &M, TargetMachine *TM,
   if (!PassPipeline.empty()) {
     assert(Passes.empty() &&
            "PassPipeline and Passes should not both contain passes");
-    if (auto Err =
-            PB.parsePassPipeline(MPM, PassPipeline, VerifyEachPass, DebugPM)) {
+    if (auto Err = PB.parsePassPipeline(MPM, PassPipeline, DebugPM)) {
       errs() << Arg0 << ": " << toString(std::move(Err)) << "\n";
       return false;
     }
@@ -394,8 +397,7 @@ bool llvm::runPassPipeline(StringRef Arg0, Module &M, TargetMachine *TM,
     std::string ModifiedPassName(PassName.begin(), PassName.end());
     if (PB.isAnalysisPassName(PassName))
       ModifiedPassName = "require<" + ModifiedPassName + ">";
-    if (auto Err = PB.parsePassPipeline(MPM, ModifiedPassName, VerifyEachPass,
-                                        DebugPM)) {
+    if (auto Err = PB.parsePassPipeline(MPM, ModifiedPassName, DebugPM)) {
       errs() << Arg0 << ": " << toString(std::move(Err)) << "\n";
       return false;
     }
diff --git a/llvm/unittests/IR/PassBuilderCallbacksTest.cpp b/llvm/unittests/IR/PassBuilderCallbacksTest.cpp
index 44c0fe9ffd1661..7052f655a422de 100644
--- a/llvm/unittests/IR/PassBuilderCallbacksTest.cpp
+++ b/llvm/unittests/IR/PassBuilderCallbacksTest.cpp
@@ -502,7 +502,7 @@ TEST_F(ModuleCallbacksTest, Passes) {
       .WillOnce(Invoke(getAnalysisResult));
 
   StringRef PipelineText = "test-transform";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
 
   PM.run(*M, AM);
@@ -547,7 +547,7 @@ TEST_F(ModuleCallbacksTest, InstrumentedPasses) {
       .Times(0);
 
   StringRef PipelineText = "test-transform";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
 
   PM.run(*M, AM);
@@ -663,7 +663,7 @@ TEST_F(ModuleCallbacksTest, InstrumentedSkippedPasses) {
 
   StringRef PipelineText = "test-transform,function(test-transform),cgscc("
                            "function(loop(test-transform)))";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
 
   PM.run(*M, AM);
@@ -675,7 +675,7 @@ TEST_F(FunctionCallbacksTest, Passes) {
       .WillOnce(Invoke(getAnalysisResult));
 
   StringRef PipelineText = "test-transform";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -725,7 +725,7 @@ TEST_F(FunctionCallbacksTest, InstrumentedPasses) {
       .Times(0);
 
   StringRef PipelineText = "test-transform";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -771,7 +771,7 @@ TEST_F(FunctionCallbacksTest, InstrumentedSkippedPasses) {
       .Times(0);
 
   StringRef PipelineText = "test-transform";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -782,7 +782,7 @@ TEST_F(LoopCallbacksTest, Passes) {
       .WillOnce(WithArgs<0, 1, 2>(Invoke(getAnalysisResult)));
 
   StringRef PipelineText = "test-transform";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -833,7 +833,7 @@ TEST_F(LoopCallbacksTest, InstrumentedPasses) {
       .Times(0);
 
   StringRef PipelineText = "test-transform";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -881,7 +881,7 @@ TEST_F(LoopCallbacksTest, InstrumentedInvalidatingPasses) {
       .Times(0);
 
   StringRef PipelineText = "test-transform";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -925,7 +925,7 @@ TEST_F(LoopCallbacksTest, InstrumentedSkippedPasses) {
       .Times(0);
 
   StringRef PipelineText = "test-transform";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -936,7 +936,7 @@ TEST_F(CGSCCCallbacksTest, Passes) {
       .WillOnce(WithArgs<0, 1, 2>(Invoke(getAnalysisResult)));
 
   StringRef PipelineText = "test-transform";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -987,7 +987,7 @@ TEST_F(CGSCCCallbacksTest, InstrumentedPasses) {
       .Times(0);
 
   StringRef PipelineText = "test-transform";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -1035,7 +1035,7 @@ TEST_F(CGSCCCallbacksTest, InstrumentedInvalidatingPasses) {
       .Times(0);
 
   StringRef PipelineText = "test-transform";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -1080,7 +1080,7 @@ TEST_F(CGSCCCallbacksTest, InstrumentedSkippedPasses) {
       .Times(0);
 
   StringRef PipelineText = "test-transform";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -1095,7 +1095,7 @@ TEST_F(ModuleCallbacksTest, AnalysisUtilities) {
   EXPECT_CALL(AnalysisHandle, invalidate(HasName("<string>"), _, _));
 
   StringRef PipelineText = "require<test-analysis>,invalidate<test-analysis>";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -1105,7 +1105,7 @@ TEST_F(CGSCCCallbacksTest, PassUtilities) {
   EXPECT_CALL(AnalysisHandle, invalidate(HasName("(foo)"), _, _));
 
   StringRef PipelineText = "require<test-analysis>,invalidate<test-analysis>";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -1115,7 +1115,7 @@ TEST_F(FunctionCallbacksTest, AnalysisUtilities) {
   EXPECT_CALL(AnalysisHandle, invalidate(HasName("foo"), _, _));
 
   StringRef PipelineText = "require<test-analysis>,invalidate<test-analysis>";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -1126,7 +1126,7 @@ TEST_F(LoopCallbacksTest, PassUtilities) {
 
   StringRef PipelineText = "require<test-analysis>,invalidate<test-analysis>";
 
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 }
@@ -1139,25 +1139,27 @@ TEST_F(LoopCallbacksTest, PassUtilities) {
 /// This test parses a pipeline named 'another-pipeline', whose only elements
 /// may be the test-transform pass or the analysis utilities
 TEST_F(ModuleCallbacksTest, ParseTopLevelPipeline) {
-  PB.registerParseTopLevelPipelineCallback([this](
-      ModulePassManager &MPM, ArrayRef<PassBuilder::PipelineElement> Pipeline,
-      bool VerifyEachPass, bool DebugLogging) {
-    auto &FirstName = Pipeline.front().Name;
-    auto &InnerPipeline = Pipeline.front().InnerPipeline;
-    if (FirstName == "another-pipeline") {
-      for (auto &E : InnerPipeline) {
-        if (parseAnalysisUtilityPasses<AnalysisT>("test-analysis", E.Name, PM))
-          continue;
-
-        if (E.Name == "test-transform") {
-          PM.addPass(PassHandle.getPass());
-          continue;
+  PB.registerParseTopLevelPipelineCallback(
+      [this](ModulePassManager &MPM,
+             ArrayRef<PassBuilder::PipelineElement> Pipeline,
+             bool DebugLogging) {
+        auto &FirstName = Pipeline.front().Name;
+        auto &InnerPipeline = Pipeline.front().InnerPipeline;
+        if (FirstName == "another-pipeline") {
+          for (auto &E : InnerPipeline) {
+            if (parseAnalysisUtilityPasses<AnalysisT>("test-analysis", E.Name,
+                                                      PM))
+              continue;
+
+            if (E.Name == "test-transform") {
+              PM.addPass(PassHandle.getPass());
+              continue;
+            }
+            return false;
+          }
         }
-        return false;
-      }
-    }
-    return true;
-  });
+        return true;
+      });
 
   EXPECT_CALL(AnalysisHandle, run(HasName("<string>"), _));
   EXPECT_CALL(PassHandle, run(HasName("<string>"), _))
@@ -1166,13 +1168,121 @@ TEST_F(ModuleCallbacksTest, ParseTopLevelPipeline) {
 
   StringRef PipelineText =
       "another-pipeline(test-transform,invalidate<test-analysis>)";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Succeeded())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
       << "Pipeline was: " << PipelineText;
   PM.run(*M, AM);
 
   /// Test the negative case
   PipelineText = "another-pipeline(instcombine)";
-  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText, true), Failed())
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Failed())
       << "Pipeline was: " << PipelineText;
 }
+
+struct CounterPass : PassInfoMixin<CounterPass> {
+  int &Counter;
+  int &I;
+
+  CounterPass(int &Counter, int &I) : Counter(Counter), I(I) {}
+
+  void impl() {
+    int C = Counter++;
+    // A pass can be run multiple times (e.g. passes added via before/after
+    // parsing passes callbacks when implicit pass managers are involved), so
+    // only take the first number.
+    if (I == 0)
+      I = C;
+  }
+
+  PreservedAnalyses run(Module &F, ModuleAnalysisManager &AM) {
+    impl();
+    return PreservedAnalyses::none();
+  }
+  PreservedAnalyses run(LazyCallGraph::SCC &C, CGSCCAnalysisManager &AM,
+                        LazyCallGraph &CG, CGSCCUpdateResult &UR) {
+    impl();
+    return PreservedAnalyses::none();
+  }
+  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM) {
+    impl();
+    return PreservedAnalyses::none();
+  }
+  PreservedAnalyses run(Loop &L, LoopAnalysisManager &AM,
+                        LoopStandardAnalysisResults &AR, LPMUpdater &U) {
+    impl();
+    return PreservedAnalyses::none();
+  }
+};
+
+TEST_F(ModuleCallbacksTest, AddPassCallbacks) {
+  int M1 = 0, M2 = 0, M3 = 0, C1 = 0, C2 = 0, C3 = 0, F1 = 0, F2 = 0, F3 = 0,
+      L1 = 0, L2 = 0, L3 = 0, Counter = 1;
+  PB.registerBeforeParsingModulePassCallback(
+      [&](ModulePassManager &MPM) { MPM.addPass(CounterPass(Counter, M1)); });
+  PB.registerAfterParsingModulePassCallback(
+      [&](ModulePassManager &MPM) { MPM.addPass(CounterPass(Counter, M3)); });
+  PB.registerBeforeParsingCGSCCPassCallback(
+      [&](CGSCCPassManager &MPM) { MPM.addPass(CounterPass(Counter, C1)); });
+  PB.registerAfterParsingCGSCCPassCallback(
+      [&](CGSCCPassManager &MPM) { MPM.addPass(CounterPass(Counter, C3)); });
+  PB.registerBeforeParsingFunctionPassCallback(
+      [&](FunctionPassManager &MPM) { MPM.addPass(CounterPass(Counter, F1)); });
+  PB.registerAfterParsingFunctionPassCallback(
+      [&](FunctionPassManager &MPM) { MPM.addPass(CounterPass(Counter, F3)); });
+  PB.registerBeforeParsingLoopPassCallback(
+      [&](LoopPassManager &MPM) { MPM.addPass(CounterPass(Counter, L1)); });
+  PB.registerAfterParsingLoopPassCallback(
+      [&](LoopPassManager &MPM) { MPM.addPass(CounterPass(Counter, L3)); });
+
+  PB.registerPipelineParsingCallback(
+      [&](StringRef Name, ModulePassManager &MPM,
+          ArrayRef<PassBuilder::PipelineElement>) {
+        if (Name == "test") {
+          MPM.addPass(CounterPass(Counter, M2));
+          return true;
+        }
+        return false;
+      });
+
+  PB.registerPipelineParsingCallback(
+      [&](StringRef Name, CGSCCPassManager &CGPM,
+          ArrayRef<PassBuilder::PipelineElement>) {
+        if (Name == "test") {
+          CGPM.addPass(CounterPass(Counter, C2));
+          return true;
+        }
+        return false;
+      });
+  PB.registerPipelineParsingCallback(
+      [&](StringRef Name, FunctionPassManager &FPM,
+          ArrayRef<PassBuilder::PipelineElement>) {
+        if (Name == "test") {
+          FPM.addPass(CounterPass(Counter, F2));
+          return true;
+        }
+        return false;
+      });
+  PB.registerPipelineParsingCallback(
+      [&](StringRef Name, LoopPassManager &LPM,
+          ArrayRef<PassBuilder::PipelineElement>) {
+        if (Name == "test") {
+          LPM.addPass(CounterPass(Counter, L2));
+          return true;
+        }
+        return false;
+      });
+
+  StringRef PipelineText = "test,cgscc(test,function(test,loop(test)))";
+  ASSERT_THAT_ERROR(PB.parsePassPipeline(PM, PipelineText), Succeeded())
+      << "Pipeline was: " << PipelineText;
+  PM.run(*M, AM);
+
+  ASSERT_LT(M1, M2);
+  ASSERT_LT(M2, M3);
+  ASSERT_LT(C1, C2);
+  ASSERT_LT(C2, C3);
+  ASSERT_LT(F1, F2);
+  ASSERT_LT(F2, F3);
+  ASSERT_LT(L1, L2);
+  ASSERT_LT(L2, L3);
+}
 } // end anonymous namespace
diff --git a/polly/lib/Support/RegisterPasses.cpp b/polly/lib/Support/RegisterPasses.cpp
index ad6edb5807ccec..e9687df6e964be 100644
--- a/polly/lib/Support/RegisterPasses.cpp
+++ b/polly/lib/Support/RegisterPasses.cpp
@@ -678,7 +678,7 @@ static bool isScopPassName(StringRef Name) {
 static bool
 parseTopLevelPipeline(ModulePassManager &MPM,
                       ArrayRef<PassBuilder::PipelineElement> Pipeline,
-                      bool VerifyEachPass, bool DebugLogging) {
+                      bool DebugLogging) {
   std::vector<PassBuilder::PipelineElement> FullPipeline;
   StringRef FirstName = Pipeline.front().Name;
 
@@ -698,11 +698,7 @@ parseTopLevelPipeline(ModulePassManager &MPM,
   }
 
   FPM.addPass(createFunctionToScopPassAdaptor(std::move(SPM)));
-  if (VerifyEachPass)
-    FPM.addPass(VerifierPass());
   MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
-  if (VerifyEachPass)
-    MPM.addPass(VerifierPass());
 
   return true;
 }