Index: llvm/include/llvm/IR/PassManager.h
===================================================================
--- llvm/include/llvm/IR/PassManager.h
+++ llvm/include/llvm/IR/PassManager.h
@@ -381,6 +381,22 @@
       Name = Name.drop_front(strlen("llvm::"));
     return Name;
   }
+
+  void buildPassesStr(PassInstrumentationCallbacks &PIC,
+                      std::string &PassesStr) {
+    auto PassName = PIC.getPassNameForClassName(name());
+    if (!PassName.empty()) {
+      if (!PassesStr.empty() && PassesStr.back() != '(')
+        PassesStr += ",";
+      PassesStr += PassName;
+      std::string Params;
+      static_cast<DerivedT *>(this)->printParams(Params);
+      if (!Params.empty())
+        PassesStr += Params;
+    }
+  }
+
+  void printParams(std::string &ParamsStr) {}
 };
 
 /// A CRTP mix-in that provides informational APIs needed for analysis passes.
@@ -480,6 +496,14 @@
     return *this;
   }
 
+  void buildPassesStr(PassInstrumentationCallbacks &PIC,
+                      std::string &PassesStr) {
+    for (unsigned Idx = 0, Size = Passes.size(); Idx != Size; ++Idx) {
+      auto *P = Passes[Idx].get();
+      P->buildPassesStr(PIC, PassesStr);
+    }
+  }
+
   /// Run all of the passes in this manager over the given unit of IR.
   /// ExtraArgs are passed to each pass.
   PreservedAnalyses run(IRUnitT &IR, AnalysisManagerT &AM,
@@ -1195,6 +1219,8 @@
 
   /// Runs the function pass across every function in the module.
   PreservedAnalyses run(Module &M, ModuleAnalysisManager &AM);
+  void buildPassesStr(PassInstrumentationCallbacks &PIC,
+                      std::string &PassesStr);
 
   static bool isRequired() { return true; }
 
Index: llvm/include/llvm/IR/PassManagerInternal.h
===================================================================
--- llvm/include/llvm/IR/PassManagerInternal.h
+++ llvm/include/llvm/IR/PassManagerInternal.h
@@ -46,6 +46,9 @@
   virtual PreservedAnalyses run(IRUnitT &IR, AnalysisManagerT &AM,
                                 ExtraArgTs... ExtraArgs) = 0;
 
+  virtual void buildPassesStr(PassInstrumentationCallbacks &PIC,
+                              std::string &PassesStr) = 0;
+  virtual void printParams(std::string &ParamsStr) = 0;
   /// Polymorphic method to access the name of a pass.
   virtual StringRef name() const = 0;
 
@@ -85,6 +88,14 @@
     return Pass.run(IR, AM, ExtraArgs...);
   }
 
+  void buildPassesStr(PassInstrumentationCallbacks &PIC,
+                      std::string &PassesStr) override {
+    Pass.buildPassesStr(PIC, PassesStr);
+  }
+  void printParams(std::string &ParamsStr) override {
+    Pass.printParams(ParamsStr);
+  }
+
   StringRef name() const override { return PassT::name(); }
 
   template <typename T>
Index: llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
===================================================================
--- llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
+++ llvm/include/llvm/Transforms/Scalar/LoopPassManager.h
@@ -424,6 +424,8 @@
 
   /// Runs the loop passes across every loop in the function.
   PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+  void buildPassesStr(PassInstrumentationCallbacks &PIC,
+                      std::string &PassesStr);
 
   static bool isRequired() { return true; }
 
Index: llvm/include/llvm/Transforms/Scalar/SimplifyCFG.h
===================================================================
--- llvm/include/llvm/Transforms/Scalar/SimplifyCFG.h
+++ llvm/include/llvm/Transforms/Scalar/SimplifyCFG.h
@@ -39,6 +39,7 @@
   /// Construct a pass with optional optimizations.
   SimplifyCFGPass(const SimplifyCFGOptions &PassOptions);
 
+  void printParams(std::string &ParamsStr);
   /// Run the pass over the function.
   PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
 };
Index: llvm/lib/IR/PassManager.cpp
===================================================================
--- llvm/lib/IR/PassManager.cpp
+++ llvm/lib/IR/PassManager.cpp
@@ -91,6 +91,15 @@
 }
 } // namespace llvm
 
+void ModuleToFunctionPassAdaptor::buildPassesStr(
+    PassInstrumentationCallbacks &PIC, std::string &PassesStr) {
+  if (!PassesStr.empty() && PassesStr.back() != '(')
+    PassesStr += ",";
+  PassesStr += "function(";
+  Pass->buildPassesStr(PIC, PassesStr);
+  PassesStr += ")";
+}
+
 PreservedAnalyses ModuleToFunctionPassAdaptor::run(Module &M,
                                                    ModuleAnalysisManager &AM) {
   FunctionAnalysisManager &FAM =
Index: llvm/lib/Passes/PassBuilder.cpp
===================================================================
--- llvm/lib/Passes/PassBuilder.cpp
+++ llvm/lib/Passes/PassBuilder.cpp
@@ -439,7 +439,7 @@
 /// it. This should be updated if new pass instrumentation wants to use the map.
 /// We currently only use this for --print-before/after.
 bool shouldPopulateClassToPassNames() {
-  return !printBeforePasses().empty() || !printAfterPasses().empty();
+  return true || !printBeforePasses().empty() || !printAfterPasses().empty();
 }
 
 } // namespace
Index: llvm/lib/Transforms/Scalar/LoopPassManager.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LoopPassManager.cpp
+++ llvm/lib/Transforms/Scalar/LoopPassManager.cpp
@@ -172,6 +172,14 @@
 }
 } // namespace llvm
 
+void FunctionToLoopPassAdaptor::buildPassesStr(
+    PassInstrumentationCallbacks &PIC, std::string &PassesStr) {
+  if (!PassesStr.empty() && PassesStr.back() != '(')
+    PassesStr += ",";
+  PassesStr += UseMemorySSA ? "loop-mssa(" : "loop(";
+  Pass->buildPassesStr(PIC, PassesStr);
+  PassesStr += ")";
+}
 PreservedAnalyses FunctionToLoopPassAdaptor::run(Function &F,
                                                  FunctionAnalysisManager &AM) {
   // Before we even compute any loop analyses, first run a miniature function
Index: llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
+++ llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
@@ -319,6 +319,25 @@
   applyCommandLineOverridesToOptions(Options);
 }
 
+void SimplifyCFGPass::printParams(std::string &ParamsStr) {
+  auto BoolHelper = [&ParamsStr](bool B, const char *S) {
+    if (!B)
+      ParamsStr += "no-";
+    ParamsStr += S;
+    ParamsStr += ";";
+  };
+  ParamsStr += "<";
+  ParamsStr +=
+      "bonus-inst-threshold=" + std::to_string(Options.BonusInstThreshold) +
+      ";";
+  BoolHelper(Options.ForwardSwitchCondToPhi, "forward-switch-cond");
+  BoolHelper(Options.ConvertSwitchToLookupTable, "switch-to-lookup");
+  BoolHelper(Options.NeedCanonicalLoop, "keep-loops");
+  BoolHelper(Options.HoistCommonInsts, "hoist-common-insts");
+  BoolHelper(Options.SinkCommonInsts, "sink-common-insts");
+  ParamsStr += ">";
+}
+
 PreservedAnalyses SimplifyCFGPass::run(Function &F,
                                        FunctionAnalysisManager &AM) {
   auto &TTI = AM.getResult<TargetIRAnalysis>(F);
Index: llvm/tools/opt/NewPMDriver.cpp
===================================================================
--- llvm/tools/opt/NewPMDriver.cpp
+++ llvm/tools/opt/NewPMDriver.cpp
@@ -452,6 +452,10 @@
   // Before executing passes, print the final values of the LLVM options.
   cl::PrintOptionValues();
 
+  std::string PassesStr;
+  MPM.buildPassesStr(PIC, PassesStr);
+  errs() << "-passes='" << PassesStr << "'\n";
+
   // Now that we have all of the passes ready, run them.
   MPM.run(M, MAM);