7 files changed, 38 insertions, 17 deletions
diff --git a/llvm/include/llvm/InitializePasses.h b/llvm/include/llvm/InitializePasses.h
index 4f3beb17..624fee4 100644
--- a/llvm/include/llvm/InitializePasses.h
+++ b/llvm/include/llvm/InitializePasses.h
@@ -428,7 +428,7 @@ void initializeThreadSanitizerLegacyPassPass(PassRegistry&);
 void initializeTwoAddressInstructionPassPass(PassRegistry&);
 void initializeTypeBasedAAWrapperPassPass(PassRegistry&);
 void initializeTypePromotionPass(PassRegistry&);
-void initializeUnifyFunctionExitNodesPass(PassRegistry&);
+void initializeUnifyFunctionExitNodesLegacyPassPass(PassRegistry &);
 void initializeUnifyLoopExitsPass(PassRegistry &);
 void initializeUnpackMachineBundlesPass(PassRegistry&);
 void initializeUnreachableBlockElimLegacyPassPass(PassRegistry&);
diff --git a/llvm/include/llvm/Transforms/Utils/UnifyFunctionExitNodes.h b/llvm/include/llvm/Transforms/Utils/UnifyFunctionExitNodes.h
index a9fe808..20b3602 100644
--- a/llvm/include/llvm/Transforms/Utils/UnifyFunctionExitNodes.h
+++ b/llvm/include/llvm/Transforms/Utils/UnifyFunctionExitNodes.h
@@ -14,19 +14,17 @@
 #ifndef LLVM_TRANSFORMS_UTILS_UNIFYFUNCTIONEXITNODES_H
 #define LLVM_TRANSFORMS_UTILS_UNIFYFUNCTIONEXITNODES_H
 
+#include "llvm/IR/PassManager.h"
 #include "llvm/Pass.h"
 
 namespace llvm {
 
 class BasicBlock;
 
-class UnifyFunctionExitNodes : public FunctionPass {
-  bool unifyUnreachableBlocks(Function &F);
-  bool unifyReturnBlocks(Function &F);
-
+class UnifyFunctionExitNodesLegacyPass : public FunctionPass {
 public:
   static char ID; // Pass identification, replacement for typeid
-  UnifyFunctionExitNodes();
+  UnifyFunctionExitNodesLegacyPass();
 
   // We can preserve non-critical-edgeness when we unify function exit nodes
   void getAnalysisUsage(AnalysisUsage &AU) const override;
@@ -36,6 +34,12 @@ public:
 
 Pass *createUnifyFunctionExitNodesPass();
 
+class UnifyFunctionExitNodesPass
+    : public PassInfoMixin<UnifyFunctionExitNodesPass> {
+public:
+  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+};
+
 } // end namespace llvm
 
 #endif // LLVM_TRANSFORMS_UTILS_UNIFYFUNCTIONEXITNODES_H
diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index 6168a764..0a3687a 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -212,6 +212,7 @@
 #include "llvm/Transforms/Utils/StripGCRelocates.h"
 #include "llvm/Transforms/Utils/StripNonLineTableDebugInfo.h"
 #include "llvm/Transforms/Utils/SymbolRewriter.h"
+#include "llvm/Transforms/Utils/UnifyFunctionExitNodes.h"
 #include "llvm/Transforms/Vectorize/LoadStoreVectorizer.h"
 #include "llvm/Transforms/Vectorize/LoopVectorize.h"
 #include "llvm/Transforms/Vectorize/SLPVectorizer.h"
diff --git a/llvm/lib/Passes/PassRegistry.def b/llvm/lib/Passes/PassRegistry.def
index 85dd963..4b14b15 100644
--- a/llvm/lib/Passes/PassRegistry.def
+++ b/llvm/lib/Passes/PassRegistry.def
@@ -240,6 +240,7 @@ FUNCTION_PASS("lowerswitch", LowerSwitchPass())
 FUNCTION_PASS("mem2reg", PromotePass())
 FUNCTION_PASS("memcpyopt", MemCpyOptPass())
 FUNCTION_PASS("mergeicmps", MergeICmpsPass())
+FUNCTION_PASS("mergereturn", UnifyFunctionExitNodesPass())
 FUNCTION_PASS("nary-reassociate", NaryReassociatePass())
 FUNCTION_PASS("newgvn", NewGVNPass())
 FUNCTION_PASS("jump-threading", JumpThreadingPass())
diff --git a/llvm/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp b/llvm/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
index 621e944..3631733 100644
--- a/llvm/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
+++ b/llvm/lib/Transforms/Utils/UnifyFunctionExitNodes.cpp
@@ -20,28 +20,33 @@
 #include "llvm/Transforms/Utils.h"
 using namespace llvm;
 
-char UnifyFunctionExitNodes::ID = 0;
+char UnifyFunctionExitNodesLegacyPass::ID = 0;
 
-UnifyFunctionExitNodes::UnifyFunctionExitNodes() : FunctionPass(ID) {
-  initializeUnifyFunctionExitNodesPass(*PassRegistry::getPassRegistry());
+UnifyFunctionExitNodesLegacyPass::UnifyFunctionExitNodesLegacyPass()
+    : FunctionPass(ID) {
+  initializeUnifyFunctionExitNodesLegacyPassPass(
+      *PassRegistry::getPassRegistry());
 }
 
-INITIALIZE_PASS(UnifyFunctionExitNodes, "mergereturn",
+INITIALIZE_PASS(UnifyFunctionExitNodesLegacyPass, "mergereturn",
                 "Unify function exit nodes", false, false)
 
 Pass *llvm::createUnifyFunctionExitNodesPass() {
-  return new UnifyFunctionExitNodes();
+  return new UnifyFunctionExitNodesLegacyPass();
 }
 
-void UnifyFunctionExitNodes::getAnalysisUsage(AnalysisUsage &AU) const{
+void UnifyFunctionExitNodesLegacyPass::getAnalysisUsage(
+    AnalysisUsage &AU) const {
   // We preserve the non-critical-edgeness property
   AU.addPreservedID(BreakCriticalEdgesID);
   // This is a cluster of orthogonal Transforms
   AU.addPreservedID(LowerSwitchID);
 }
 
-bool UnifyFunctionExitNodes::unifyUnreachableBlocks(Function &F) {
-  std::vector<BasicBlock*> UnreachableBlocks;
+namespace {
+
+bool unifyUnreachableBlocks(Function &F) {
+  std::vector<BasicBlock *> UnreachableBlocks;
 
   for (BasicBlock &I : F)
     if (isa<UnreachableInst>(I.getTerminator()))
@@ -62,7 +67,7 @@ bool UnifyFunctionExitNodes::unifyUnreachableBlocks(Function &F) {
   return true;
 }
 
-bool UnifyFunctionExitNodes::unifyReturnBlocks(Function &F) {
+bool unifyReturnBlocks(Function &F) {
   std::vector<BasicBlock *> ReturningBlocks;
 
   for (BasicBlock &I : F)
@@ -103,13 +108,22 @@ bool UnifyFunctionExitNodes::unifyReturnBlocks(Function &F) {
 
   return true;
 }
+} // namespace
 
 // Unify all exit nodes of the CFG by creating a new BasicBlock, and converting
 // all returns to unconditional branches to this new basic block. Also, unify
 // all unreachable blocks.
-bool UnifyFunctionExitNodes::runOnFunction(Function &F) {
+bool UnifyFunctionExitNodesLegacyPass::runOnFunction(Function &F) {
   bool Changed = false;
   Changed |= unifyUnreachableBlocks(F);
   Changed |= unifyReturnBlocks(F);
   return Changed;
 }
+
+PreservedAnalyses UnifyFunctionExitNodesPass::run(Function &F,
+                                                  FunctionAnalysisManager &AM) {
+  bool Changed = false;
+  Changed |= unifyUnreachableBlocks(F);
+  Changed |= unifyReturnBlocks(F);
+  return Changed ? PreservedAnalyses() : PreservedAnalyses::all();
+}
diff --git a/llvm/lib/Transforms/Utils/Utils.cpp b/llvm/lib/Transforms/Utils/Utils.cpp
index 5f97596..aadf41c 100644
--- a/llvm/lib/Transforms/Utils/Utils.cpp
+++ b/llvm/lib/Transforms/Utils/Utils.cpp
@@ -38,7 +38,7 @@ void llvm::initializeTransformUtils(PassRegistry &Registry) {
   initializeNameAnonGlobalLegacyPassPass(Registry);
   initializePromoteLegacyPassPass(Registry);
   initializeStripNonLineTableDebugLegacyPassPass(Registry);
-  initializeUnifyFunctionExitNodesPass(Registry);
+  initializeUnifyFunctionExitNodesLegacyPassPass(Registry);
   initializeMetaRenamerPass(Registry);
   initializeStripGCRelocatesLegacyPass(Registry);
   initializePredicateInfoPrinterLegacyPassPass(Registry);
diff --git a/llvm/test/Transforms/UnifyFunctionExitNodes/unreachable-blocks-status.ll b/llvm/test/Transforms/UnifyFunctionExitNodes/unreachable-blocks-status.ll
index f1ee196..e4feae5 100644
--- a/llvm/test/Transforms/UnifyFunctionExitNodes/unreachable-blocks-status.ll
+++ b/llvm/test/Transforms/UnifyFunctionExitNodes/unreachable-blocks-status.ll
@@ -1,4 +1,5 @@
 ; RUN: opt -mergereturn -enable-new-pm=0 -S < %s | FileCheck %s
+; RUN: opt -passes='break-crit-edges,lowerswitch,mergereturn' -S < %s | FileCheck %s
 
 ; The pass did previously not report the correct Modified status in the case
 ; where a function had at most one return block, and an unified unreachable