Revert "[PGO] Context sensitive PGO (part 1)"

This reverts commit r354930, it was causing UBSan failures.

llvm-svn: 354953
diff --git a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
index c956f4e..bb2e335 100644
--- a/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
+++ b/llvm/lib/Transforms/Instrumentation/PGOInstrumentation.cpp
@@ -65,7 +65,6 @@
 #include "llvm/Analysis/IndirectCallVisitor.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/OptimizationRemarkEmitter.h"
-#include "llvm/Analysis/ProfileSummaryInfo.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/BasicBlock.h"
 #include "llvm/IR/CFG.h"
@@ -133,19 +132,6 @@
 STATISTIC(NumOfPGOMismatch, "Number of functions having mismatch profile.");
 STATISTIC(NumOfPGOMissing, "Number of functions without profile.");
 STATISTIC(NumOfPGOICall, "Number of indirect call value instrumentations.");
-STATISTIC(NumOfCSPGOInstrument, "Number of edges instrumented in CSPGO.");
-STATISTIC(NumOfCSPGOSelectInsts,
-          "Number of select instruction instrumented in CSPGO.");
-STATISTIC(NumOfCSPGOMemIntrinsics,
-          "Number of mem intrinsics instrumented in CSPGO.");
-STATISTIC(NumOfCSPGOEdge, "Number of edges in CSPGO.");
-STATISTIC(NumOfCSPGOBB, "Number of basic-blocks in CSPGO.");
-STATISTIC(NumOfCSPGOSplit, "Number of critical edge splits in CSPGO.");
-STATISTIC(NumOfCSPGOFunc,
-          "Number of functions having valid profile counts in CSPGO.");
-STATISTIC(NumOfCSPGOMismatch,
-          "Number of functions having mismatch profile in CSPGO.");
-STATISTIC(NumOfCSPGOMissing, "Number of functions without profile in CSPGO.");
 
 // Command line option to specify the file to read profile from. This is
 // mainly used for testing.
@@ -397,8 +383,7 @@
 public:
   static char ID;
 
-  PGOInstrumentationGenLegacyPass(bool IsCS = false)
-      : ModulePass(ID), IsCS(IsCS) {
+  PGOInstrumentationGenLegacyPass() : ModulePass(ID) {
     initializePGOInstrumentationGenLegacyPassPass(
         *PassRegistry::getPassRegistry());
   }
@@ -406,8 +391,6 @@
   StringRef getPassName() const override { return "PGOInstrumentationGenPass"; }
 
 private:
-  // Is this is context-sensitive instrumentation.
-  bool IsCS;
   bool runOnModule(Module &M) override;
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
@@ -420,8 +403,8 @@
   static char ID;
 
   // Provide the profile filename as the parameter.
-  PGOInstrumentationUseLegacyPass(std::string Filename = "", bool IsCS = false)
-      : ModulePass(ID), ProfileFileName(std::move(Filename)), IsCS(IsCS) {
+  PGOInstrumentationUseLegacyPass(std::string Filename = "")
+      : ModulePass(ID), ProfileFileName(std::move(Filename)) {
     if (!PGOTestProfileFile.empty())
       ProfileFileName = PGOTestProfileFile;
     initializePGOInstrumentationUseLegacyPassPass(
@@ -432,38 +415,14 @@
 
 private:
   std::string ProfileFileName;
-  // Is this is context-sensitive instrumentation use.
-  bool IsCS;
 
   bool runOnModule(Module &M) override;
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.addRequired<ProfileSummaryInfoWrapperPass>();
     AU.addRequired<BlockFrequencyInfoWrapperPass>();
   }
 };
 
-class PGOInstrumentationGenCreateVarLegacyPass : public ModulePass {
-public:
-  static char ID;
-  StringRef getPassName() const override {
-    return "PGOInstrumentationGenCreateVarPass";
-  }
-  PGOInstrumentationGenCreateVarLegacyPass(std::string CSInstrName = "")
-      : ModulePass(ID), InstrProfileOutput(CSInstrName) {
-    initializePGOInstrumentationGenCreateVarLegacyPassPass(
-        *PassRegistry::getPassRegistry());
-  }
-
-private:
-  bool runOnModule(Module &M) override {
-    createProfileFileNameVar(M, InstrProfileOutput);
-    createIRLevelProfileFlagVar(M, true);
-    return false;
-  }
-  std::string InstrProfileOutput;
-};
-
 } // end anonymous namespace
 
 char PGOInstrumentationGenLegacyPass::ID = 0;
@@ -475,8 +434,8 @@
 INITIALIZE_PASS_END(PGOInstrumentationGenLegacyPass, "pgo-instr-gen",
                     "PGO instrumentation.", false, false)
 
-ModulePass *llvm::createPGOInstrumentationGenLegacyPass(bool IsCS) {
-  return new PGOInstrumentationGenLegacyPass(IsCS);
+ModulePass *llvm::createPGOInstrumentationGenLegacyPass() {
+  return new PGOInstrumentationGenLegacyPass();
 }
 
 char PGOInstrumentationUseLegacyPass::ID = 0;
@@ -485,25 +444,11 @@
                       "Read PGO instrumentation profile.", false, false)
 INITIALIZE_PASS_DEPENDENCY(BlockFrequencyInfoWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(BranchProbabilityInfoWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(ProfileSummaryInfoWrapperPass)
 INITIALIZE_PASS_END(PGOInstrumentationUseLegacyPass, "pgo-instr-use",
                     "Read PGO instrumentation profile.", false, false)
 
-ModulePass *llvm::createPGOInstrumentationUseLegacyPass(StringRef Filename,
-                                                        bool IsCS) {
-  return new PGOInstrumentationUseLegacyPass(Filename.str(), IsCS);
-}
-
-char PGOInstrumentationGenCreateVarLegacyPass::ID = 0;
-
-INITIALIZE_PASS(PGOInstrumentationGenCreateVarLegacyPass,
-                "pgo-instr-gen-create-var",
-                "Create PGO instrumentation version variable for CSPGO.", false,
-                false)
-
-ModulePass *
-llvm::createPGOInstrumentationGenCreateVarLegacyPass(StringRef CSInstrName) {
-  return new PGOInstrumentationGenCreateVarLegacyPass(CSInstrName);
+ModulePass *llvm::createPGOInstrumentationUseLegacyPass(StringRef Filename) {
+  return new PGOInstrumentationUseLegacyPass(Filename.str());
 }
 
 namespace {
@@ -551,9 +496,6 @@
 private:
   Function &F;
 
-  // Is this is context-sensitive instrumentation.
-  bool IsCS;
-
   // A map that stores the Comdat group in function F.
   std::unordered_multimap<Comdat *, GlobalValue *> &ComdatMembers;
 
@@ -593,23 +535,15 @@
       Function &Func,
       std::unordered_multimap<Comdat *, GlobalValue *> &ComdatMembers,
       bool CreateGlobalVar = false, BranchProbabilityInfo *BPI = nullptr,
-      BlockFrequencyInfo *BFI = nullptr, bool IsCS = false)
-      : F(Func), IsCS(IsCS), ComdatMembers(ComdatMembers),
-        ValueSites(IPVK_Last + 1), SIVisitor(Func), MIVisitor(Func),
-        MST(F, BPI, BFI) {
+      BlockFrequencyInfo *BFI = nullptr)
+      : F(Func), ComdatMembers(ComdatMembers), ValueSites(IPVK_Last + 1),
+        SIVisitor(Func), MIVisitor(Func), MST(F, BPI, BFI) {
     // This should be done before CFG hash computation.
     SIVisitor.countSelects(Func);
     MIVisitor.countMemIntrinsics(Func);
-    if (!IsCS) {
-      NumOfPGOSelectInsts += SIVisitor.getNumOfSelectInsts();
-      NumOfPGOMemIntrinsics += MIVisitor.getNumOfMemIntrinsics();
-      NumOfPGOBB += MST.BBInfos.size();
-      ValueSites[IPVK_IndirectCallTarget] = findIndirectCalls(Func);
-    } else {
-      NumOfCSPGOSelectInsts += SIVisitor.getNumOfSelectInsts();
-      NumOfCSPGOMemIntrinsics += MIVisitor.getNumOfMemIntrinsics();
-      NumOfCSPGOBB += MST.BBInfos.size();
-    }
+    NumOfPGOSelectInsts += SIVisitor.getNumOfSelectInsts();
+    NumOfPGOMemIntrinsics += MIVisitor.getNumOfMemIntrinsics();
+    ValueSites[IPVK_IndirectCallTarget] = findIndirectCalls(Func);
     ValueSites[IPVK_MemOPSize] = MIVisitor.findMemIntrinsics(Func);
 
     FuncName = getPGOFuncName(F);
@@ -618,12 +552,13 @@
       renameComdatFunction();
     LLVM_DEBUG(dumpInfo("after CFGMST"));
 
+    NumOfPGOBB += MST.BBInfos.size();
     for (auto &E : MST.AllEdges) {
       if (E->Removed)
         continue;
-      IsCS ? NumOfCSPGOEdge++ : NumOfPGOEdge++;
+      NumOfPGOEdge++;
       if (!E->InMST)
-        IsCS ? NumOfCSPGOInstrument++ : NumOfPGOInstrument++;
+        NumOfPGOInstrument++;
     }
 
     if (CreateGlobalVar)
@@ -662,17 +597,9 @@
     }
   }
   JC.update(Indexes);
-
-  // Hash format for context sensitive profile. Reserve 4 bits for other
-  // information.
   FunctionHash = (uint64_t)SIVisitor.getNumOfSelectInsts() << 56 |
                  (uint64_t)ValueSites[IPVK_IndirectCallTarget].size() << 48 |
-                 //(uint64_t)ValueSites[IPVK_MemOPSize].size() << 40 |
                  (uint64_t)MST.AllEdges.size() << 32 | JC.getCRC();
-  // Reserve bit 60-63 for other information purpose.
-  FunctionHash &= 0x0FFFFFFFFFFFFFFF;
-  if (IsCS)
-    NamedInstrProfRecord::setCSFlagInHash(FunctionHash);
   LLVM_DEBUG(dbgs() << "Function Hash Computation for " << F.getName() << ":\n"
                     << " CRC = " << JC.getCRC()
                     << ", Selects = " << SIVisitor.getNumOfSelectInsts()
@@ -778,7 +705,7 @@
 
   // For a critical edge, we have to split. Instrument the newly
   // created BB.
-  IsCS ? NumOfCSPGOSplit++ : NumOfPGOSplit++;
+  NumOfPGOSplit++;
   LLVM_DEBUG(dbgs() << "Split critical edge: " << getBBInfo(SrcBB).Index
                     << " --> " << getBBInfo(DestBB).Index << "\n");
   unsigned SuccNum = GetSuccessorNumber(SrcBB, DestBB);
@@ -793,14 +720,12 @@
 // Critical edges will be split.
 static void instrumentOneFunc(
     Function &F, Module *M, BranchProbabilityInfo *BPI, BlockFrequencyInfo *BFI,
-    std::unordered_multimap<Comdat *, GlobalValue *> &ComdatMembers,
-    bool IsCS) {
+    std::unordered_multimap<Comdat *, GlobalValue *> &ComdatMembers) {
   // Split indirectbr critical edges here before computing the MST rather than
   // later in getInstrBB() to avoid invalidating it.
   SplitIndirectBrCriticalEdges(F, BPI, BFI);
-
   FuncPGOInstrumentation<PGOEdge, BBInfo> FuncInfo(F, ComdatMembers, true, BPI,
-                                                   BFI, IsCS);
+                                                   BFI);
   unsigned NumCounters = FuncInfo.getNumCounters();
 
   uint32_t I = 0;
@@ -927,10 +852,10 @@
   PGOUseFunc(Function &Func, Module *Modu,
              std::unordered_multimap<Comdat *, GlobalValue *> &ComdatMembers,
              BranchProbabilityInfo *BPI = nullptr,
-             BlockFrequencyInfo *BFIin = nullptr, bool IsCS = false)
+             BlockFrequencyInfo *BFIin = nullptr)
       : F(Func), M(Modu), BFI(BFIin),
-        FuncInfo(Func, ComdatMembers, false, BPI, BFIin, IsCS),
-        FreqAttr(FFA_Normal), IsCS(IsCS) {}
+        FuncInfo(Func, ComdatMembers, false, BPI, BFIin),
+        FreqAttr(FFA_Normal) {}
 
   // Read counts for the instrumented BB from profile.
   bool readCounters(IndexedInstrProfReader *PGOReader, bool &AllZeros);
@@ -1003,9 +928,6 @@
   // Function hotness info derived from profile.
   FuncFreqAttr FreqAttr;
 
-  // Is to use the context sensitive profile.
-  bool IsCS;
-
   // Find the Instrumented BB and set the value.
   void setInstrumentedCounts(const std::vector<uint64_t> &CountFromProfile);
 
@@ -1099,31 +1021,23 @@
     handleAllErrors(std::move(E), [&](const InstrProfError &IPE) {
       auto Err = IPE.get();
       bool SkipWarning = false;
-      LLVM_DEBUG(dbgs() << "Error in reading profile for Func "
-                        << FuncInfo.FuncName << ": ");
       if (Err == instrprof_error::unknown_function) {
-        IsCS ? NumOfCSPGOMissing++ : NumOfPGOMissing++;
+        NumOfPGOMissing++;
         SkipWarning = !PGOWarnMissing;
-        LLVM_DEBUG(dbgs() << "unknown function");
       } else if (Err == instrprof_error::hash_mismatch ||
                  Err == instrprof_error::malformed) {
-        IsCS ? NumOfCSPGOMismatch++ : NumOfPGOMismatch++;
+        NumOfPGOMismatch++;
         SkipWarning =
             NoPGOWarnMismatch ||
             (NoPGOWarnMismatchComdat &&
              (F.hasComdat() ||
               F.getLinkage() == GlobalValue::AvailableExternallyLinkage));
-        LLVM_DEBUG(dbgs() << "hash mismatch (skip=" << SkipWarning << ")");
       }
 
-      LLVM_DEBUG(dbgs() << " IsCS=" << IsCS << "\n");
       if (SkipWarning)
         return;
 
-      std::string Msg = IPE.message() + std::string(" ") + F.getName().str() +
-                        std::string(" Hash = ") +
-                        std::to_string(FuncInfo.FunctionHash);
-
+      std::string Msg = IPE.message() + std::string(" ") + F.getName().str();
       Ctx.diagnose(
           DiagnosticInfoPGOProfile(M->getName().data(), Msg, DS_Warning));
     });
@@ -1132,7 +1046,7 @@
   ProfileRecord = std::move(Result.get());
   std::vector<uint64_t> &CountFromProfile = ProfileRecord.Counts;
 
-  IsCS ? NumOfCSPGOFunc++ : NumOfPGOFunc++;
+  NumOfPGOFunc++;
   LLVM_DEBUG(dbgs() << CountFromProfile.size() << " counts\n");
   uint64_t ValueSum = 0;
   for (unsigned I = 0, S = CountFromProfile.size(); I < S; I++) {
@@ -1147,11 +1061,7 @@
   getBBInfo(nullptr).UnknownCountInEdge = 2;
 
   setInstrumentedCounts(CountFromProfile);
-#if 0
-  ProgramMaxCount = PGOReader->getMaximumFunctionCount(IsCS);
-#else
   ProgramMaxCount = PGOReader->getMaximumFunctionCount();
-#endif
   return true;
 }
 
@@ -1256,8 +1166,7 @@
 // Assign the scaled count values to the BB with multiple out edges.
 void PGOUseFunc::setBranchWeights() {
   // Generate MD_prof metadata for every branch instruction.
-  LLVM_DEBUG(dbgs() << "\nSetting branch weights for func " << F.getName()
-                    << " IsCS=" << IsCS << "\n");
+  LLVM_DEBUG(dbgs() << "\nSetting branch weights.\n");
   for (auto &BB : F) {
     Instruction *TI = BB.getTerminator();
     if (TI->getNumSuccessors() < 2)
@@ -1265,7 +1174,6 @@
     if (!(isa<BranchInst>(TI) || isa<SwitchInst>(TI) ||
           isa<IndirectBrInst>(TI)))
       continue;
-
     if (getBBInfo(&BB).CountValue == 0)
       continue;
 
@@ -1443,6 +1351,24 @@
   }
 }
 
+// Create a COMDAT variable INSTR_PROF_RAW_VERSION_VAR to make the runtime
+// aware this is an ir_level profile so it can set the version flag.
+static void createIRLevelProfileFlagVariable(Module &M) {
+  Type *IntTy64 = Type::getInt64Ty(M.getContext());
+  uint64_t ProfileVersion = (INSTR_PROF_RAW_VERSION | VARIANT_MASK_IR_PROF);
+  auto IRLevelVersionVariable = new GlobalVariable(
+      M, IntTy64, true, GlobalVariable::ExternalLinkage,
+      Constant::getIntegerValue(IntTy64, APInt(64, ProfileVersion)),
+      INSTR_PROF_QUOTE(INSTR_PROF_RAW_VERSION_VAR));
+  IRLevelVersionVariable->setVisibility(GlobalValue::DefaultVisibility);
+  Triple TT(M.getTargetTriple());
+  if (!TT.supportsCOMDAT())
+    IRLevelVersionVariable->setLinkage(GlobalValue::WeakAnyLinkage);
+  else
+    IRLevelVersionVariable->setComdat(M.getOrInsertComdat(
+        StringRef(INSTR_PROF_QUOTE(INSTR_PROF_RAW_VERSION_VAR))));
+}
+
 // Collect the set of members for each Comdat in module M and store
 // in ComdatMembers.
 static void collectComdatMembers(
@@ -1463,11 +1389,8 @@
 
 static bool InstrumentAllFunctions(
     Module &M, function_ref<BranchProbabilityInfo *(Function &)> LookupBPI,
-    function_ref<BlockFrequencyInfo *(Function &)> LookupBFI, bool IsCS) {
-  // For the context-sensitve instrumentation, we should have a separated pass
-  // (before LTO/ThinLTO linking) to create these variables.
-  if (!IsCS)
-    createIRLevelProfileFlagVar(M, /* IsCS */ false);
+    function_ref<BlockFrequencyInfo *(Function &)> LookupBFI) {
+  createIRLevelProfileFlagVariable(M);
   std::unordered_multimap<Comdat *, GlobalValue *> ComdatMembers;
   collectComdatMembers(M, ComdatMembers);
 
@@ -1476,7 +1399,7 @@
       continue;
     auto *BPI = LookupBPI(F);
     auto *BFI = LookupBFI(F);
-    instrumentOneFunc(F, &M, BPI, BFI, ComdatMembers, IsCS);
+    instrumentOneFunc(F, &M, BPI, BFI, ComdatMembers);
   }
   return true;
 }
@@ -1491,7 +1414,7 @@
   auto LookupBFI = [this](Function &F) {
     return &this->getAnalysis<BlockFrequencyInfoWrapperPass>(F).getBFI();
   };
-  return InstrumentAllFunctions(M, LookupBPI, LookupBFI, IsCS);
+  return InstrumentAllFunctions(M, LookupBPI, LookupBFI);
 }
 
 PreservedAnalyses PGOInstrumentationGen::run(Module &M,
@@ -1505,7 +1428,7 @@
     return &FAM.getResult<BlockFrequencyAnalysis>(F);
   };
 
-  if (!InstrumentAllFunctions(M, LookupBPI, LookupBFI, IsCS))
+  if (!InstrumentAllFunctions(M, LookupBPI, LookupBFI))
     return PreservedAnalyses::all();
 
   return PreservedAnalyses::none();
@@ -1514,7 +1437,7 @@
 static bool annotateAllFunctions(
     Module &M, StringRef ProfileFileName, StringRef ProfileRemappingFileName,
     function_ref<BranchProbabilityInfo *(Function &)> LookupBPI,
-    function_ref<BlockFrequencyInfo *(Function &)> LookupBFI, bool IsCS) {
+    function_ref<BlockFrequencyInfo *(Function &)> LookupBFI) {
   LLVM_DEBUG(dbgs() << "Read in profile counters: ");
   auto &Ctx = M.getContext();
   // Read the counter array from file.
@@ -1535,11 +1458,6 @@
                                           StringRef("Cannot get PGOReader")));
     return false;
   }
-#if 0
-  if (!PGOReader->hasCSIRLevelProfile() && IsCS)
-    return false;
-#endif
-
   // TODO: might need to change the warning once the clang option is finalized.
   if (!PGOReader->isIRLevelProfile()) {
     Ctx.diagnose(DiagnosticInfoPGOProfile(
@@ -1559,7 +1477,7 @@
     // Split indirectbr critical edges here before computing the MST rather than
     // later in getInstrBB() to avoid invalidating it.
     SplitIndirectBrCriticalEdges(F, BPI, BFI);
-    PGOUseFunc Func(F, &M, ComdatMembers, BPI, BFI, IsCS);
+    PGOUseFunc Func(F, &M, ComdatMembers, BPI, BFI);
     bool AllZeros = false;
     if (!Func.readCounters(PGOReader.get(), AllZeros))
       continue;
@@ -1607,14 +1525,7 @@
       }
     }
   }
-#if 0
-  M.setProfileSummary(PGOReader->getSummary(IsCS).getMD(M.getContext()),
-                      IsCS ? ProfileSummary::PSK_CSInstr
-                           : ProfileSummary::PSK_Instr);
-#else
   M.setProfileSummary(PGOReader->getSummary().getMD(M.getContext()));
-#endif
-
   // Set function hotness attribute from the profile.
   // We have to apply these attributes at the end because their presence
   // can affect the BranchProbabilityInfo of any callers, resulting in an
@@ -1633,10 +1544,9 @@
 }
 
 PGOInstrumentationUse::PGOInstrumentationUse(std::string Filename,
-                                             std::string RemappingFilename,
-                                             bool IsCS)
+                                             std::string RemappingFilename)
     : ProfileFileName(std::move(Filename)),
-      ProfileRemappingFileName(std::move(RemappingFilename)), IsCS(IsCS) {
+      ProfileRemappingFileName(std::move(RemappingFilename)) {
   if (!PGOTestProfileFile.empty())
     ProfileFileName = PGOTestProfileFile;
   if (!PGOTestProfileRemappingFile.empty())
@@ -1656,7 +1566,7 @@
   };
 
   if (!annotateAllFunctions(M, ProfileFileName, ProfileRemappingFileName,
-                            LookupBPI, LookupBFI, IsCS))
+                            LookupBPI, LookupBFI))
     return PreservedAnalyses::all();
 
   return PreservedAnalyses::none();
@@ -1673,8 +1583,7 @@
     return &this->getAnalysis<BlockFrequencyInfoWrapperPass>(F).getBFI();
   };
 
-  return annotateAllFunctions(M, ProfileFileName, "", LookupBPI, LookupBFI,
-                              IsCS);
+  return annotateAllFunctions(M, ProfileFileName, "", LookupBPI, LookupBFI);
 }
 
 static std::string getSimpleNodeName(const BasicBlock *Node) {