[NFC][PartialInliner]: Clean up code

[etiotto]

Summary

This is a NFC patch. In the patch I:

• make member function const where possible,
• use LLVM_DEBUG to print debug tracers rather than a custom option,
• pass by reference to avoid null checking
• code formatting

[etiotto]

Fix clang-format

[fhahn]

LGTM, thanks.

[etiotto]

Note: this failure looks bogus to me as it also happens in other PRs like https://reviews.llvm.org/D89964

linux > HWAddressSanitizer-x86_64.TestCases::sizes.cpp
Script:
--
: 'RUN: at line 3';      /mnt/disks/ssd0/agent/llvm-project/build/./bin/clang  --driver-mode=g++  -m64  -gline-tables-only -fsanitize=hwaddress -fuse-ld=lld -mcmodel=large -mllvm -hwasan-globals -mllvm -hwasan-use-short-granules -mllvm -hwasan-instrument-landing-pads=0 -mllvm -hwasan-instrument-personality-functions /mnt/disks/ssd0/agent/llvm-project/compiler-rt/test/hwasan/TestCases/sizes.cpp -nostdlib++ -lstdc++ -o /mnt/disks/ssd0/agent/llvm-project/build/projects/compiler-rt/test/hwasan/X86_64/TestCases/Output/sizes.cpp.tmp

llvm/lib/Transforms/IPO/PartialInlining.cpp

ForceLiveExit("pi-force-live-exit-outline", cl::init(false), cl::Hidden,
                cl::desc("Force outline regions with live exits"));
 
 // Command line option to enable marking outline functions with Cold Calling
 // Convention. The default is false:
 static cl::opt<bool>
     MarkOutlinedColdCC("pi-mark-coldcc", cl::init(false), cl::Hidden,
                        cl::desc("Mark outline function calls with ColdCC"));
 
-#ifndef NDEBUG
-// Command line option to debug partial-inlining. The default is none:
-static cl::opt<bool> TracePartialInlining("trace-partial-inlining",
-                                          cl::init(false), cl::Hidden,
-                                          cl::desc("Trace partial inlining."));
-#endif
-
 // This is an option used by testing:
 static cl::opt<bool> SkipCostAnalysis("skip-partial-inlining-cost-analysis",
                                       cl::init(false), cl::ZeroOrMore,
                                       cl::ReallyHidden,
                                       cl::desc("Skip Cost Analysis"));
 // Used to determine if a cold region is worth outlining based on
 // its inlining cost compared to the original function.  Default is set at 10%.
 // ie. if the cold region reduces the inlining cost of the original function by

 
 namespace {
 
 struct FunctionOutliningInfo {
   FunctionOutliningInfo() = default;
 
   // Returns the number of blocks to be inlined including all blocks
   // in Entries and one return block.
-  unsigned GetNumInlinedBlocks() const { return Entries.size() + 1; }
+  unsigned getNumInlinedBlocks() const { return Entries.size() + 1; }
 
   // A set of blocks including the function entry that guard
   // the region to be outlined.
   SmallVector<BasicBlock *, 4> Entries;
 
   // The return block that is not included in the outlined region.
   BasicBlock *ReturnBlock = nullptr;
 
struct PartialInlinerImpl {
   bool run(Module &M);
   // Main part of the transformation that calls helper functions to find
   // outlining candidates, clone & outline the function, and attempt to
   // partially inline the resulting function. Returns true if
   // inlining was successful, false otherwise.  Also returns the outline
   // function (only if we partially inlined early returns) as there is a
   // possibility to further "peel" early return statements that were left in the
   // outline function due to code size.
-  std::pair<bool, Function *> unswitchFunction(Function *F);
+  std::pair<bool, Function *> unswitchFunction(Function &F);
 
   // This class speculatively clones the function to be partial inlined.
   // At the end of partial inlining, the remaining callsites to the cloned
   // function that are not partially inlined will be fixed up to reference
   // the original function, and the cloned function will be erased.
   struct FunctionCloner {
     // Two constructors, one for single region outlining, the other for
     // multi-region outlining.
     FunctionCloner(Function *F, FunctionOutliningInfo *OI,
                    OptimizationRemarkEmitter &ORE,
                    function_ref<AssumptionCache *(Function &)> LookupAC,
                    function_ref<TargetTransformInfo &(Function &)> GetTTI);
     FunctionCloner(Function *F, FunctionOutliningMultiRegionInfo *OMRI,
                    OptimizationRemarkEmitter &ORE,
                    function_ref<AssumptionCache *(Function &)> LookupAC,
                    function_ref<TargetTransformInfo &(Function &)> GetTTI);
 
     ~FunctionCloner();
 
     // Prepare for function outlining: making sure there is only
     // one incoming edge from the extracted/outlined region to
     // the return block.
-    void NormalizeReturnBlock();
+    void normalizeReturnBlock() const;
 
     // Do function outlining for cold regions.
     bool doMultiRegionFunctionOutlining();
     // Do function outlining for region after early return block(s).
     // NOTE: For vararg functions that do the vararg handling in the outlined
     //       function, we temporarily generate IR that does not properly
     //       forward varargs to the outlined function. Calling InlineFunction
     //       will update calls to the outlined functions to properly forward
private:
   function_ref<BlockFrequencyInfo &(Function &)> GetBFI;
   function_ref<const TargetLibraryInfo &(Function &)> GetTLI;
   ProfileSummaryInfo &PSI;
 
   // Return the frequency of the OutlininingBB relative to F's entry point.
   // The result is no larger than 1 and is represented using BP.
   // (Note that the outlined region's 'head' block can only have incoming
   // edges from the guarding entry blocks).
-  BranchProbability getOutliningCallBBRelativeFreq(FunctionCloner &Cloner);
+  BranchProbability
+  getOutliningCallBBRelativeFreq(FunctionCloner &Cloner) const;
 
   // Return true if the callee of CB should be partially inlined with
   // profit.
   bool shouldPartialInline(CallBase &CB, FunctionCloner &Cloner,
                            BlockFrequency WeightedOutliningRcost,
-                           OptimizationRemarkEmitter &ORE);
+                           OptimizationRemarkEmitter &ORE) const;
 
   // Try to inline DuplicateFunction (cloned from F with call to
   // the OutlinedFunction into its callers. Return true
   // if there is any successful inlining.
   bool tryPartialInline(FunctionCloner &Cloner);
 
   // Compute the mapping from use site of DuplicationFunction to the enclosing
   // BB's profile count.
-  void computeCallsiteToProfCountMap(Function *DuplicateFunction,
-                                     DenseMap<User *, uint64_t> &SiteCountMap);
+  void
+  computeCallsiteToProfCountMap(Function *DuplicateFunction,
+                                DenseMap<User *, uint64_t> &SiteCountMap) const;
 
-  bool IsLimitReached() {
+  bool isLimitReached() const {
     return (MaxNumPartialInlining != -1 &&
             NumPartialInlining >= MaxNumPartialInlining);
   }
 
   static CallBase *getSupportedCallBase(User *U) {
     if (isa<CallInst>(U) || isa<InvokeInst>(U))
       return cast<CallBase>(U);
     llvm_unreachable("All uses must be calls");
     return nullptr;
   }
 
-  static CallBase *getOneCallSiteTo(Function *F) {
-    User *User = *F->user_begin();
+  static CallBase *getOneCallSiteTo(Function &F) {
+    User *User = *F.user_begin();
     return getSupportedCallBase(User);
   }
 
-  std::tuple<DebugLoc, BasicBlock *> getOneDebugLoc(Function *F) {
+  std::tuple<DebugLoc, BasicBlock *> getOneDebugLoc(Function &F) const {
     CallBase *CB = getOneCallSiteTo(F);
     DebugLoc DLoc = CB->getDebugLoc();
     BasicBlock *Block = CB->getParent();
     return std::make_tuple(DLoc, Block);
   }
 
   // Returns the costs associated with function outlining:
   // - The first value is the non-weighted runtime cost for making the call
   //   to the outlined function, including the addtional  setup cost in the
   //    outlined function itself;
   // - The second value is the estimated size of the new call sequence in
   //   basic block Cloner.OutliningCallBB;
-  std::tuple<int, int> computeOutliningCosts(FunctionCloner &Cloner);
+  std::tuple<int, int> computeOutliningCosts(FunctionCloner &Cloner) const;
 
   // Compute the 'InlineCost' of block BB. InlineCost is a proxy used to
   // approximate both the size and runtime cost (Note that in the current
   // inline cost analysis, there is no clear distinction there either).
   static int computeBBInlineCost(BasicBlock *BB, TargetTransformInfo *TTI);
 
-  std::unique_ptr<FunctionOutliningInfo> computeOutliningInfo(Function *F);
+  std::unique_ptr<FunctionOutliningInfo>
+  computeOutliningInfo(Function &F) const;
+
   std::unique_ptr<FunctionOutliningMultiRegionInfo>
-  computeOutliningColdRegionsInfo(Function *F, OptimizationRemarkEmitter &ORE);
+  computeOutliningColdRegionsInfo(Function &F,
+                                  OptimizationRemarkEmitter &ORE) const;
 };
 
 struct PartialInlinerLegacyPass : public ModulePass {
   static char ID; // Pass identification, replacement for typeid
 
   PartialInlinerLegacyPass() : ModulePass(ID) {
     initializePartialInlinerLegacyPassPass(*PassRegistry::getPassRegistry());
   }
return PartialInlinerImpl(GetAssumptionCache, LookupAssumptionCache, GetTTI,
                               GetTLI, PSI)
         .run(M);
   }
 };
 
 } // end anonymous namespace
 
 std::unique_ptr<FunctionOutliningMultiRegionInfo>
-PartialInlinerImpl::computeOutliningColdRegionsInfo(Function *F,
-                                                    OptimizationRemarkEmitter &ORE) {
-  BasicBlock *EntryBlock = &F->front();
+PartialInlinerImpl::computeOutliningColdRegionsInfo(
+    Function &F, OptimizationRemarkEmitter &ORE) const {
+  BasicBlock *EntryBlock = &F.front();
 
-  DominatorTree DT(*F);
+  DominatorTree DT(F);
   LoopInfo LI(DT);
-  BranchProbabilityInfo BPI(*F, LI);
+  BranchProbabilityInfo BPI(F, LI);
   std::unique_ptr<BlockFrequencyInfo> ScopedBFI;
   BlockFrequencyInfo *BFI;
   if (!GetBFI) {
-    ScopedBFI.reset(new BlockFrequencyInfo(*F, BPI, LI));
+    ScopedBFI.reset(new BlockFrequencyInfo(F, BPI, LI));
     BFI = ScopedBFI.get();
   } else
-    BFI = &(GetBFI(*F));
+    BFI = &(GetBFI(F));
 
   // Return if we don't have profiling information.
   if (!PSI.hasInstrumentationProfile())
     return std::unique_ptr<FunctionOutliningMultiRegionInfo>();
 
   std::unique_ptr<FunctionOutliningMultiRegionInfo> OutliningInfo =
       std::make_unique<FunctionOutliningMultiRegionInfo>();
 
for (auto *Block : BlockList) {
             ORE.emit([&]() {
               return OptimizationRemarkMissed(DEBUG_TYPE, "MultiExitRegion",
                                               &SI->front())
                      << "Region dominated by "
                      << ore::NV("Block", BlockList.front()->getName())
                      << " has more than one region exit edge.";
             });
             return nullptr;
-          } else
-            ExitBlock = Block;
+          }
+
         }
       }
     }
     return ExitBlock;
   };
 
   auto BBProfileCount = [BFI](BasicBlock *BB) {
     return BFI->getBlockProfileCount(BB)
                ? BFI->getBlockProfileCount(BB).getValue()
                : 0;
   };
 
   // Use the same computeBBInlineCost function to compute the cost savings of
   // the outlining the candidate region.
-  TargetTransformInfo *FTTI = &GetTTI(*F);
+  TargetTransformInfo *FTTI = &GetTTI(F);
   int OverallFunctionCost = 0;
-  for (auto &BB : *F)
+  for (auto &BB : F)
     OverallFunctionCost += computeBBInlineCost(&BB, FTTI);
 
-#ifndef NDEBUG
-  if (TracePartialInlining)
-    dbgs() << "OverallFunctionCost = " << OverallFunctionCost << "\n";
-#endif
+  LLVM_DEBUG(dbgs() << "OverallFunctionCost = " << OverallFunctionCost
+                    << "\n";);
+
   int MinOutlineRegionCost =
       static_cast<int>(OverallFunctionCost * MinRegionSizeRatio);
   BranchProbability MinBranchProbability(
       static_cast<int>(ColdBranchRatio * MinBlockCounterExecution),
       MinBlockCounterExecution);
   bool ColdCandidateFound = false;
   BasicBlock *CurrEntry = EntryBlock;
   std::vector<BasicBlock *> DFS;
   DenseMap<BasicBlock *, bool> VisitedMap;
   DFS.push_back(CurrEntry);
   VisitedMap[CurrEntry] = true;
+
   // Use Depth First Search on the basic blocks to find CFG edges that are
   // considered cold.
   // Cold regions considered must also have its inline cost compared to the
   // overall inline cost of the original function.  The region is outlined only
   // if it reduced the inline cost of the function by 'MinOutlineRegionCost' or
   // more.
   while (!DFS.empty()) {
-    auto *thisBB = DFS.back();
+    auto *ThisBB = DFS.back();
     DFS.pop_back();
     // Only consider regions with predecessor blocks that are considered
     // not-cold (default: part of the top 99.99% of all block counters)
     // AND greater than our minimum block execution count (default: 100).
-    if (PSI.isColdBlock(thisBB, BFI) ||
-        BBProfileCount(thisBB) < MinBlockCounterExecution)
+    if (PSI.isColdBlock(ThisBB, BFI) ||
+        BBProfileCount(ThisBB) < MinBlockCounterExecution)
       continue;
-    for (auto SI = succ_begin(thisBB); SI != succ_end(thisBB); ++SI) {
+    for (auto SI = succ_begin(ThisBB); SI != succ_end(ThisBB); ++SI) {
       if (VisitedMap[*SI])
         continue;
       VisitedMap[*SI] = true;
       DFS.push_back(*SI);
       // If branch isn't cold, we skip to the next one.
-      BranchProbability SuccProb = BPI.getEdgeProbability(thisBB, *SI);
+      BranchProbability SuccProb = BPI.getEdgeProbability(ThisBB, *SI);
       if (SuccProb > MinBranchProbability)
         continue;
-#ifndef NDEBUG
-      if (TracePartialInlining) {
-        dbgs() << "Found cold edge: " << thisBB->getName() << "->"
-               << (*SI)->getName() << "\nBranch Probability = " << SuccProb
-               << "\n";
-      }
-#endif
+
+      LLVM_DEBUG(dbgs() << "Found cold edge: " << ThisBB->getName() << "->"
+                        << SI->getName()
+                        << "\nBranch Probability = " << SuccProb << "\n";);
+
       SmallVector<BasicBlock *, 8> DominateVector;
       DT.getDescendants(*SI, DominateVector);
+
       // We can only outline single entry regions (for now).
       if (!IsSingleEntry(DominateVector))
         continue;
+
       BasicBlock *ExitBlock = nullptr;
       // We can only outline single exit regions (for now).
       if (!(ExitBlock = IsSingleExit(DominateVector)))
         continue;
+
       int OutlineRegionCost = 0;
       for (auto *BB : DominateVector)
         OutlineRegionCost += computeBBInlineCost(BB, &GetTTI(*BB->getParent()));
 
-#ifndef NDEBUG
-      if (TracePartialInlining)
-        dbgs() << "OutlineRegionCost = " << OutlineRegionCost << "\n";
-#endif
+      LLVM_DEBUG(dbgs() << "OutlineRegionCost = " << OutlineRegionCost
+                        << "\n";);
 
       if (OutlineRegionCost < MinOutlineRegionCost) {
         ORE.emit([&]() {
           return OptimizationRemarkAnalysis(DEBUG_TYPE, "TooCostly",
                                             &SI->front())
-                 << ore::NV("Callee", F) << " inline cost-savings smaller than "
+                 << ore::NV("Callee", &F)
+                 << " inline cost-savings smaller than "
                  << ore::NV("Cost", MinOutlineRegionCost);
         });
         continue;
       }
       // For now, ignore blocks that belong to a SISE region that is a
       // candidate for outlining.  In the future, we may want to look
       // at inner regions because the outer region may have live-exit
       // variables.
       for (auto *BB : DominateVector)
         VisitedMap[BB] = true;
+
       // ReturnBlock here means the block after the outline call
       BasicBlock *ReturnBlock = ExitBlock->getSingleSuccessor();
-      // assert(ReturnBlock && "ReturnBlock is NULL somehow!");
       FunctionOutliningMultiRegionInfo::OutlineRegionInfo RegInfo(
           DominateVector, DominateVector.front(), ExitBlock, ReturnBlock);
       OutliningInfo->ORI.push_back(RegInfo);
-#ifndef NDEBUG
-      if (TracePartialInlining) {
-        dbgs() << "Found Cold Candidate starting at block: "
-               << DominateVector.front()->getName() << "\n";
-      }
-#endif
+      LLVM_DEBUG(dbgs() << "Found Cold Candidate starting at block: "
+                        << DominateVector.front()->getName() << "\n";);
       ColdCandidateFound = true;
       NumColdRegionsFound++;
     }
   }
+
   if (ColdCandidateFound)
     return OutliningInfo;
-  else
-    return std::unique_ptr<FunctionOutliningMultiRegionInfo>();
+
 }
 
 std::unique_ptr<FunctionOutliningInfo>
-PartialInlinerImpl::computeOutliningInfo(Function *F) {
-  BasicBlock *EntryBlock = &F->front();
+PartialInlinerImpl::computeOutliningInfo(Function &F) const {
+  BasicBlock *EntryBlock = &F.front();
   BranchInst *BR = dyn_cast<BranchInst>(EntryBlock->getTerminator());
   if (!BR || BR->isUnconditional())
     return std::unique_ptr<FunctionOutliningInfo>();
 
   // Returns true if Succ is BB's successor
   auto IsSuccessor = [](BasicBlock *Succ, BasicBlock *BB) {
     return is_contained(successors(BB), Succ);
   };
std::unique_ptr<FunctionOutliningInfo> OutliningInfo =
       std::make_unique<FunctionOutliningInfo>();
 
   BasicBlock *CurrEntry = EntryBlock;
   bool CandidateFound = false;
   do {
     // The number of blocks to be inlined has already reached
     // the limit. When MaxNumInlineBlocks is set to 0 or 1, this
     // disables partial inlining for the function.
-    if (OutliningInfo->GetNumInlinedBlocks() >= MaxNumInlineBlocks)
+    if (OutliningInfo->getNumInlinedBlocks() >= MaxNumInlineBlocks)
       break;
 
     if (succ_size(CurrEntry) != 2)
       break;
 
     BasicBlock *Succ1 = *succ_begin(CurrEntry);
     BasicBlock *Succ2 = *(succ_begin(CurrEntry) + 1);
 
     BasicBlock *ReturnBlock, *NonReturnBlock;
     std::tie(ReturnBlock, NonReturnBlock) = GetReturnBlock(Succ1, Succ2);
 
     if (ReturnBlock) {
       OutliningInfo->Entries.push_back(CurrEntry);
       OutliningInfo->ReturnBlock = ReturnBlock;
       OutliningInfo->NonReturnBlock = NonReturnBlock;
       CandidateFound = true;
       break;
     }
 
-    BasicBlock *CommSucc;
-    BasicBlock *OtherSucc;
+    BasicBlock *CommSucc, *OtherSucc;
     std::tie(CommSucc, OtherSucc) = GetCommonSucc(Succ1, Succ2);
 
     if (!CommSucc)
       break;
 
     OutliningInfo->Entries.push_back(CurrEntry);
     CurrEntry = OtherSucc;
   } while (true);
 
   if (!CandidateFound)
     return std::unique_ptr<FunctionOutliningInfo>();
 
   // Do sanity check of the entries: threre should not
   // be any successors (not in the entry set) other than
   // {ReturnBlock, NonReturnBlock}
-  assert(OutliningInfo->Entries[0] == &F->front() &&
+  assert(OutliningInfo->Entries[0] == &F.front() &&
          "Function Entry must be the first in Entries vector");
   DenseSet<BasicBlock *> Entries;
   for (BasicBlock *E : OutliningInfo->Entries)
     Entries.insert(E);
 
   // Returns true of BB has Predecessor which is not
   // in Entries set.
   auto HasNonEntryPred = [Entries](BasicBlock *BB) {
-    for (auto Pred : predecessors(BB)) {
+    for (auto *Pred : predecessors(BB)) {
       if (!Entries.count(Pred))
         return true;
     }
     return false;
   };
   auto CheckAndNormalizeCandidate =
       [Entries, HasNonEntryPred](FunctionOutliningInfo *OutliningInfo) {
         for (BasicBlock *E : OutliningInfo->Entries) {
-          for (auto Succ : successors(E)) {
+          for (auto *Succ : successors(E)) {
             if (Entries.count(Succ))
               continue;
             if (Succ == OutliningInfo->ReturnBlock)
               OutliningInfo->ReturnBlockPreds.push_back(E);
             else if (Succ != OutliningInfo->NonReturnBlock)
               return false;
           }
           // There should not be any outside incoming edges either:
           if (HasNonEntryPred(E))
             return false;
         }
         return true;
       };
 
   if (!CheckAndNormalizeCandidate(OutliningInfo.get()))
     return std::unique_ptr<FunctionOutliningInfo>();
 
   // Now further growing the candidate's inlining region by
   // peeling off dominating blocks from the outlining region:
-  while (OutliningInfo->GetNumInlinedBlocks() < MaxNumInlineBlocks) {
+  while (OutliningInfo->getNumInlinedBlocks() < MaxNumInlineBlocks) {
     BasicBlock *Cand = OutliningInfo->NonReturnBlock;
     if (succ_size(Cand) != 2)
       break;
 
     if (HasNonEntryPred(Cand))
       break;
 
     BasicBlock *Succ1 = *succ_begin(Cand);
while (OutliningInfo->getNumInlinedBlocks() < MaxNumInlineBlocks) {
     OutliningInfo->ReturnBlockPreds.push_back(Cand);
     Entries.insert(Cand);
   }
 
   return OutliningInfo;
 }
 
 // Check if there is PGO data or user annotated branch data:
-static bool hasProfileData(Function *F, FunctionOutliningInfo *OI) {
-  if (F->hasProfileData())
+static bool hasProfileData(const Function &F, const FunctionOutliningInfo &OI) {
+  if (F.hasProfileData())
     return true;
   // Now check if any of the entry block has MD_prof data:
-  for (auto *E : OI->Entries) {
+  for (auto *E : OI.Entries) {
     BranchInst *BR = dyn_cast<BranchInst>(E->getTerminator());
     if (!BR || BR->isUnconditional())
       continue;
     uint64_t T, F;
     if (BR->extractProfMetadata(T, F))
       return true;
   }
   return false;
 }
 
-BranchProbability
-PartialInlinerImpl::getOutliningCallBBRelativeFreq(FunctionCloner &Cloner) {
+BranchProbability PartialInlinerImpl::getOutliningCallBBRelativeFreq(
+    FunctionCloner &Cloner) const {
   BasicBlock *OutliningCallBB = Cloner.OutlinedFunctions.back().second;
   auto EntryFreq =
       Cloner.ClonedFuncBFI->getBlockFreq(&Cloner.ClonedFunc->getEntryBlock());
   auto OutliningCallFreq =
       Cloner.ClonedFuncBFI->getBlockFreq(OutliningCallBB);
   // FIXME Hackery needed because ClonedFuncBFI is based on the function BEFORE
   // we outlined any regions, so we may encounter situations where the
   // OutliningCallFreq is *slightly* bigger than the EntryFreq.
-  if (OutliningCallFreq.getFrequency() > EntryFreq.getFrequency()) {
+  if (OutliningCallFreq.getFrequency() > EntryFreq.getFrequency())
     OutliningCallFreq = EntryFreq;
-  }
+
   auto OutlineRegionRelFreq = BranchProbability::getBranchProbability(
       OutliningCallFreq.getFrequency(), EntryFreq.getFrequency());
 
-  if (hasProfileData(Cloner.OrigFunc, Cloner.ClonedOI.get()))
+  if (hasProfileData(*Cloner.OrigFunc, *Cloner.ClonedOI.get()))
     return OutlineRegionRelFreq;
 
   // When profile data is not available, we need to be conservative in
   // estimating the overall savings. Static branch prediction can usually
   // guess the branch direction right (taken/non-taken), but the guessed
   // branch probability is usually not biased enough. In case when the
   // outlined region is predicted to be likely, its probability needs
   // to be made higher (more biased) to not under-estimate the cost of
BranchProbability PartialInlinerImpl::getOutliningCallBBRelativeFreq(
   OutlineRegionRelFreq = std::max(
       OutlineRegionRelFreq, BranchProbability(OutlineRegionFreqPercent, 100));
 
   return OutlineRegionRelFreq;
 }
 
 bool PartialInlinerImpl::shouldPartialInline(
     CallBase &CB, FunctionCloner &Cloner, BlockFrequency WeightedOutliningRcost,
-    OptimizationRemarkEmitter &ORE) {
+    OptimizationRemarkEmitter &ORE) const {
   using namespace ore;
 
   Function *Callee = CB.getCalledFunction();
   assert(Callee == Cloner.ClonedFunc);
 
   if (SkipCostAnalysis)
     return isInlineViable(*Callee).isSuccess();
 
if (SwitchInst *SI = dyn_cast<SwitchInst>(&I)) {
       continue;
     }
     InlineCost += InlineConstants::InstrCost;
   }
   return InlineCost;
 }
 
 std::tuple<int, int>
-PartialInlinerImpl::computeOutliningCosts(FunctionCloner &Cloner) {
+PartialInlinerImpl::computeOutliningCosts(FunctionCloner &Cloner) const {
   int OutliningFuncCallCost = 0, OutlinedFunctionCost = 0;
   for (auto FuncBBPair : Cloner.OutlinedFunctions) {
     Function *OutlinedFunc = FuncBBPair.first;
     BasicBlock* OutliningCallBB = FuncBBPair.second;
     // Now compute the cost of the call sequence to the outlined function
     // 'OutlinedFunction' in BB 'OutliningCallBB':
     auto *OutlinedFuncTTI = &GetTTI(*OutlinedFunc);
     OutliningFuncCallCost +=
PartialInlinerImpl::computeOutliningCosts(FunctionCloner &Cloner) const {
   return std::make_tuple(OutliningFuncCallCost, OutliningRuntimeOverhead);
 }
 
 // Create the callsite to profile count map which is
 // used to update the original function's entry count,
 // after the function is partially inlined into the callsite.
 void PartialInlinerImpl::computeCallsiteToProfCountMap(
     Function *DuplicateFunction,
-    DenseMap<User *, uint64_t> &CallSiteToProfCountMap) {
+    DenseMap<User *, uint64_t> &CallSiteToProfCountMap) const {
   std::vector<User *> Users(DuplicateFunction->user_begin(),
                             DuplicateFunction->user_end());
   Function *CurrentCaller = nullptr;
   std::unique_ptr<BlockFrequencyInfo> TempBFI;
   BlockFrequencyInfo *CurrentCallerBFI = nullptr;
 
   auto ComputeCurrBFI = [&,this](Function *Caller) {
       // For the old pass manager:
PartialInlinerImpl::FunctionCloner::FunctionCloner(
   ClonedOI = std::make_unique<FunctionOutliningInfo>();
 
   // Clone the function, so that we can hack away on it.
   ValueToValueMapTy VMap;
   ClonedFunc = CloneFunction(F, VMap);
 
   ClonedOI->ReturnBlock = cast<BasicBlock>(VMap[OI->ReturnBlock]);
   ClonedOI->NonReturnBlock = cast<BasicBlock>(VMap[OI->NonReturnBlock]);
-  for (BasicBlock *BB : OI->Entries) {
+  for (BasicBlock *BB : OI->Entries)
     ClonedOI->Entries.push_back(cast<BasicBlock>(VMap[BB]));
-  }
+
   for (BasicBlock *E : OI->ReturnBlockPreds) {
     BasicBlock *NewE = cast<BasicBlock>(VMap[E]);
     ClonedOI->ReturnBlockPreds.push_back(NewE);
   }
   // Go ahead and update all uses to the duplicate, so that we can just
   // use the inliner functionality when we're done hacking.
   F->replaceAllUsesWith(ClonedFunc);
 }
PartialInlinerImpl::FunctionCloner::FunctionCloner(
   ValueToValueMapTy VMap;
   ClonedFunc = CloneFunction(F, VMap);
 
   // Go through all Outline Candidate Regions and update all BasicBlock
   // information.
   for (FunctionOutliningMultiRegionInfo::OutlineRegionInfo RegionInfo :
        OI->ORI) {
     SmallVector<BasicBlock *, 8> Region;
-    for (BasicBlock *BB : RegionInfo.Region) {
+    for (BasicBlock *BB : RegionInfo.Region)
       Region.push_back(cast<BasicBlock>(VMap[BB]));
-    }
+
     BasicBlock *NewEntryBlock = cast<BasicBlock>(VMap[RegionInfo.EntryBlock]);
     BasicBlock *NewExitBlock = cast<BasicBlock>(VMap[RegionInfo.ExitBlock]);
     BasicBlock *NewReturnBlock = nullptr;
     if (RegionInfo.ReturnBlock)
       NewReturnBlock = cast<BasicBlock>(VMap[RegionInfo.ReturnBlock]);
     FunctionOutliningMultiRegionInfo::OutlineRegionInfo MappedRegionInfo(
         Region, NewEntryBlock, NewExitBlock, NewReturnBlock);
     ClonedOMRI->ORI.push_back(MappedRegionInfo);
   }
   // Go ahead and update all uses to the duplicate, so that we can just
   // use the inliner functionality when we're done hacking.
   F->replaceAllUsesWith(ClonedFunc);
 }
 
-void PartialInlinerImpl::FunctionCloner::NormalizeReturnBlock() {
-  auto getFirstPHI = [](BasicBlock *BB) {
+void PartialInlinerImpl::FunctionCloner::normalizeReturnBlock() const {
+  auto GetFirstPHI = [](BasicBlock *BB) {
     BasicBlock::iterator I = BB->begin();
     PHINode *FirstPhi = nullptr;
     while (I != BB->end()) {
       PHINode *Phi = dyn_cast<PHINode>(I);
       if (!Phi)
         break;
       if (!FirstPhi) {
         FirstPhi = Phi;
if (!ClonedOI)
     return;
 
   // Special hackery is needed with PHI nodes that have inputs from more than
   // one extracted block.  For simplicity, just split the PHIs into a two-level
   // sequence of PHIs, some of which will go in the extracted region, and some
   // of which will go outside.
   BasicBlock *PreReturn = ClonedOI->ReturnBlock;
   // only split block when necessary:
-  PHINode *FirstPhi = getFirstPHI(PreReturn);
+  PHINode *FirstPhi = GetFirstPHI(PreReturn);
   unsigned NumPredsFromEntries = ClonedOI->ReturnBlockPreds.size();
 
   if (!FirstPhi || FirstPhi->getNumIncomingValues() <= NumPredsFromEntries + 1)
     return;
 
   auto IsTrivialPhi = [](PHINode *PN) -> Value * {
     Value *CommonValue = PN->getIncomingValue(0);
     if (all_of(PN->incoming_values(),
if (auto *OldPhiVal = IsTrivialPhi(OldPhi)) {
       OldPhi->replaceAllUsesWith(OldPhiVal);
       DeadPhis.push_back(OldPhi);
     }
     ++I;
   }
   for (auto *DP : DeadPhis)
     DP->eraseFromParent();
 
-  for (auto E : ClonedOI->ReturnBlockPreds) {
+  for (auto *E : ClonedOI->ReturnBlockPreds)
     E->getTerminator()->replaceUsesOfWith(PreReturn, ClonedOI->ReturnBlock);
-  }
-}
 
 bool PartialInlinerImpl::FunctionCloner::doMultiRegionFunctionOutlining() {
 
   auto ComputeRegionCost = [&](SmallVectorImpl<BasicBlock *> &Region) {
     int Cost = 0;
     for (BasicBlock* BB : Region)
       Cost += computeBBInlineCost(BB, &GetTTI(*BB->getParent()));
     return Cost;
for (FunctionOutliningMultiRegionInfo::OutlineRegionInfo RegionInfo :
 
     CodeExtractor CE(RegionInfo.Region, &DT, /*AggregateArgs*/ false,
                      ClonedFuncBFI.get(), &BPI,
                      LookupAC(*RegionInfo.EntryBlock->getParent()),
                      /* AllowVarargs */ false);
 
     CE.findInputsOutputs(Inputs, Outputs, Sinks);
 
-#ifndef NDEBUG
-    if (TracePartialInlining) {
+    LLVM_DEBUG({
       dbgs() << "inputs: " << Inputs.size() << "\n";
       dbgs() << "outputs: " << Outputs.size() << "\n";
       for (Value *value : Inputs)
         dbgs() << "value used in func: " << *value << "\n";
       for (Value *output : Outputs)
         dbgs() << "instr used in func: " << *output << "\n";
-    }
-#endif
+    });
+
     // Do not extract regions that have live exit variables.
     if (Outputs.size() > 0 && !ForceLiveExit)
       continue;
 
-    Function *OutlinedFunc = CE.extractCodeRegion(CEAC);
-
-    if (OutlinedFunc) {
-      CallBase *OCS = PartialInlinerImpl::getOneCallSiteTo(OutlinedFunc);
+    if (Function *OutlinedFunc = CE.extractCodeRegion(CEAC)) {
+      CallBase *OCS = PartialInlinerImpl::getOneCallSiteTo(*OutlinedFunc);
       BasicBlock *OutliningCallBB = OCS->getParent();
       assert(OutliningCallBB->getParent() == ClonedFunc);
       OutlinedFunctions.push_back(std::make_pair(OutlinedFunc,OutliningCallBB));
       NumColdRegionsOutlined++;
       OutlinedRegionCost += CurrentOutlinedRegionCost;
 
       if (MarkOutlinedColdCC) {
         OutlinedFunc->setCallingConv(CallingConv::Cold);
PartialInlinerImpl::FunctionCloner::doSingleRegionFunctionOutlining() {
   Function *OutlinedFunc =
       CodeExtractor(ToExtract, &DT, /*AggregateArgs*/ false,
                     ClonedFuncBFI.get(), &BPI, LookupAC(*ClonedFunc),
                     /* AllowVarargs */ true)
           .extractCodeRegion(CEAC);
 
   if (OutlinedFunc) {
     BasicBlock *OutliningCallBB =
-        PartialInlinerImpl::getOneCallSiteTo(OutlinedFunc)
-            ->getParent();
+        PartialInlinerImpl::getOneCallSiteTo(*OutlinedFunc)->getParent();
     assert(OutliningCallBB->getParent() == ClonedFunc);
     OutlinedFunctions.push_back(std::make_pair(OutlinedFunc, OutliningCallBB));
   } else
     ORE.emit([&]() {
       return OptimizationRemarkMissed(DEBUG_TYPE, "ExtractFailed",
                                       &ToExtract.front()->front())
              << "Failed to extract region at block "
              << ore::NV("Block", ToExtract.front());
if (!IsFunctionInlined) {
     // reference.
     for (auto FuncBBPair : OutlinedFunctions) {
       Function *Func = FuncBBPair.first;
       Func->eraseFromParent();
     }
   }
 }
 
-std::pair<bool, Function *> PartialInlinerImpl::unswitchFunction(Function *F) {
-
-  if (F->hasAddressTaken())
+std::pair<bool, Function *> PartialInlinerImpl::unswitchFunction(Function &F) {
+  if (F.hasAddressTaken())
     return {false, nullptr};
 
   // Let inliner handle it
-  if (F->hasFnAttribute(Attribute::AlwaysInline))
+  if (F.hasFnAttribute(Attribute::AlwaysInline))
     return {false, nullptr};
 
-  if (F->hasFnAttribute(Attribute::NoInline))
+  if (F.hasFnAttribute(Attribute::NoInline))
     return {false, nullptr};
 
-  if (PSI.isFunctionEntryCold(F))
+  if (PSI.isFunctionEntryCold(&F))
     return {false, nullptr};
 
-  if (F->users().empty())
+  if (F.users().empty())
     return {false, nullptr};
 
-  OptimizationRemarkEmitter ORE(F);
+  OptimizationRemarkEmitter ORE(&F);
 
   // Only try to outline cold regions if we have a profile summary, which
   // implies we have profiling information.
-  if (PSI.hasProfileSummary() && F->hasProfileData() &&
+  if (PSI.hasProfileSummary() && F.hasProfileData() &&
       !DisableMultiRegionPartialInline) {
     std::unique_ptr<FunctionOutliningMultiRegionInfo> OMRI =
         computeOutliningColdRegionsInfo(F, ORE);
     if (OMRI) {
-      FunctionCloner Cloner(F, OMRI.get(), ORE, LookupAssumptionCache, GetTTI);
+      FunctionCloner Cloner(&F, OMRI.get(), ORE, LookupAssumptionCache, GetTTI);
 
-#ifndef NDEBUG
-      if (TracePartialInlining) {
+      LLVM_DEBUG({
         dbgs() << "HotCountThreshold = " << PSI.getHotCountThreshold() << "\n";
         dbgs() << "ColdCountThreshold = " << PSI.getColdCountThreshold()
                << "\n";
-      }
-#endif
+      });
+
       bool DidOutline = Cloner.doMultiRegionFunctionOutlining();
 
       if (DidOutline) {
-#ifndef NDEBUG
-        if (TracePartialInlining) {
+        LLVM_DEBUG({
           dbgs() << ">>>>>> Outlined (Cloned) Function >>>>>>\n";
           Cloner.ClonedFunc->print(dbgs());
           dbgs() << "<<<<<< Outlined (Cloned) Function <<<<<<\n";
-        }
-#endif
+        });
 
         if (tryPartialInline(Cloner))
           return {true, nullptr};
       }
     }
   }
 
   // Fall-thru to regular partial inlining if we:
   //    i) can't find any cold regions to outline, or
   //   ii) can't inline the outlined function anywhere.
   std::unique_ptr<FunctionOutliningInfo> OI = computeOutliningInfo(F);
   if (!OI)
     return {false, nullptr};
 
-  FunctionCloner Cloner(F, OI.get(), ORE, LookupAssumptionCache, GetTTI);
-  Cloner.NormalizeReturnBlock();
+  FunctionCloner Cloner(&F, OI.get(), ORE, LookupAssumptionCache, GetTTI);
+  Cloner.normalizeReturnBlock();
 
   Function *OutlinedFunction = Cloner.doSingleRegionFunctionOutlining();
 
   if (!OutlinedFunction)
     return {false, nullptr};
 
-  bool AnyInline = tryPartialInline(Cloner);
-
-  if (AnyInline)
+  if (tryPartialInline(Cloner))
     return {true, OutlinedFunction};
 
   return {false, nullptr};
 }
 
 bool PartialInlinerImpl::tryPartialInline(FunctionCloner &Cloner) {
   if (Cloner.OutlinedFunctions.empty())
     return false;
 
   int SizeCost = 0;
   BlockFrequency WeightedRcost;
   int NonWeightedRcost;
   std::tie(SizeCost, NonWeightedRcost) = computeOutliningCosts(Cloner);
 
   // Only calculate RelativeToEntryFreq when we are doing single region
   // outlining.
   BranchProbability RelativeToEntryFreq;
-  if (Cloner.ClonedOI) {
+  if (Cloner.ClonedOI)
     RelativeToEntryFreq = getOutliningCallBBRelativeFreq(Cloner);
-  } else
+  else
     // RelativeToEntryFreq doesn't make sense when we have more than one
     // outlined call because each call will have a different relative frequency
     // to the entry block.  We can consider using the average, but the
     // usefulness of that information is questionable. For now, assume we never
     // execute the calls to outlined functions.
     RelativeToEntryFreq = BranchProbability(0, 1);
 
   WeightedRcost = BlockFrequency(NonWeightedRcost) * RelativeToEntryFreq;
 
   // The call sequence(s) to the outlined function(s) are larger than the sum of
   // the original outlined region size(s), it does not increase the chances of
   // inlining the function with outlining (The inliner uses the size increase to
   // model the cost of inlining a callee).
   if (!SkipCostAnalysis && Cloner.OutlinedRegionCost < SizeCost) {
     OptimizationRemarkEmitter OrigFuncORE(Cloner.OrigFunc);
     DebugLoc DLoc;
     BasicBlock *Block;
-    std::tie(DLoc, Block) = getOneDebugLoc(Cloner.ClonedFunc);
+    std::tie(DLoc, Block) = getOneDebugLoc(*Cloner.ClonedFunc);
     OrigFuncORE.emit([&]() {
       return OptimizationRemarkAnalysis(DEBUG_TYPE, "OutlineRegionTooSmall",
                                         DLoc, Block)
              << ore::NV("Function", Cloner.OrigFunc)
              << " not partially inlined into callers (Original Size = "
              << ore::NV("OutlinedRegionOriginalSize", Cloner.OutlinedRegionCost)
              << ", Size of call sequence to outlined function = "
              << ore::NV("NewSize", SizeCost) << ")";
bool PartialInlinerImpl::tryPartialInline(FunctionCloner &Cloner) {
 
   uint64_t CalleeEntryCountV =
       (CalleeEntryCount ? CalleeEntryCount.getCount() : 0);
 
   bool AnyInline = false;
   for (User *User : Users) {
     CallBase *CB = getSupportedCallBase(User);
 
-    if (IsLimitReached())
+    if (isLimitReached())
       continue;
 
     OptimizationRemarkEmitter CallerORE(CB->getCaller());
     if (!shouldPartialInline(*CB, Cloner, WeightedRcost, CallerORE))
       continue;
 
     // Construct remark before doing the inlining, as after successful inlining
     // the callsite is removed.
for (User *User : Users) {
 
     AnyInline = true;
     NumPartialInlining++;
     // Update the stats
     if (Cloner.ClonedOI)
       NumPartialInlined++;
     else
       NumColdOutlinePartialInlined++;
-
   }
 
   if (AnyInline) {
     Cloner.IsFunctionInlined = true;
     if (CalleeEntryCount)
       Cloner.OrigFunc->setEntryCount(
           CalleeEntryCount.setCount(CalleeEntryCountV));
     OptimizationRemarkEmitter OrigFuncORE(Cloner.OrigFunc);
     OrigFuncORE.emit([&]() {
       return OptimizationRemark(DEBUG_TYPE, "PartiallyInlined", Cloner.OrigFunc)
              << "Partially inlined into at least one caller";
     });
-
   }
 
   return AnyInline;
 }
 
 bool PartialInlinerImpl::run(Module &M) {
   if (DisablePartialInlining)
     return false;
for (User *U : CurrFunc->users())
       if (Instruction *I = dyn_cast<Instruction>(U))
         if (I->getParent()->getParent() == CurrFunc) {
           Recursive = true;
           break;
         }
     if (Recursive)
       continue;
 
-    std::pair<bool, Function * > Result = unswitchFunction(CurrFunc);
+    std::pair<bool, Function *> Result = unswitchFunction(*CurrFunc);
     if (Result.second)
       Worklist.push_back(Result.second);
     Changed |= Result.first;
   }
 
   return Changed;
 }