text: //===- InstrProf.cpp - Instrumented profiling format support --------------===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  //
  // This file contains support for clang's instrumentation based PGO and
  // coverage.
  //
  //===----------------------------------------------------------------------===//
  
  #include "llvm/ProfileData/InstrProf.h"
  #include "llvm/ADT/ArrayRef.h"
  #include "llvm/ADT/SmallString.h"
  #include "llvm/ADT/SmallVector.h"
  #include "llvm/ADT/StringExtras.h"
  #include "llvm/ADT/StringRef.h"
  #include "llvm/ADT/Triple.h"
  #include "llvm/Config/config.h"
  #include "llvm/IR/Constant.h"
  #include "llvm/IR/Constants.h"
  #include "llvm/IR/Function.h"
  #include "llvm/IR/GlobalValue.h"
  #include "llvm/IR/GlobalVariable.h"
  #include "llvm/IR/Instruction.h"
  #include "llvm/IR/LLVMContext.h"
  #include "llvm/IR/MDBuilder.h"
  #include "llvm/IR/Metadata.h"
  #include "llvm/IR/Module.h"
  #include "llvm/IR/Type.h"
  #include "llvm/ProfileData/InstrProfReader.h"
  #include "llvm/Support/Casting.h"
  #include "llvm/Support/CommandLine.h"
  #include "llvm/Support/Compiler.h"
  #include "llvm/Support/Compression.h"
  #include "llvm/Support/Endian.h"
  #include "llvm/Support/Error.h"
  #include "llvm/Support/ErrorHandling.h"
  #include "llvm/Support/LEB128.h"
  #include "llvm/Support/ManagedStatic.h"
  #include "llvm/Support/MathExtras.h"
  #include "llvm/Support/Path.h"
  #include "llvm/Support/SwapByteOrder.h"
  #include <algorithm>
  #include <cassert>
  #include <cstddef>
  #include <cstdint>
  #include <cstring>
  #include <memory>
  #include <string>
  #include <system_error>
  #include <utility>
  #include <vector>
  
  using namespace llvm;
  
  static cl::opt<bool> StaticFuncFullModulePrefix(
      "static-func-full-module-prefix", cl::init(true), cl::Hidden,
      cl::desc("Use full module build paths in the profile counter names for "
               "static functions."));
  
  // This option is tailored to users that have different top-level directory in
  // profile-gen and profile-use compilation. Users need to specific the number
  // of levels to strip. A value larger than the number of directories in the
  // source file will strip all the directory names and only leave the basename.
  //
  // Note current ThinLTO module importing for the indirect-calls assumes
  // the source directory name not being stripped. A non-zero option value here
  // can potentially prevent some inter-module indirect-call-promotions.
  static cl::opt<unsigned> StaticFuncStripDirNamePrefix(
      "static-func-strip-dirname-prefix", cl::init(0), cl::Hidden,
      cl::desc("Strip specified level of directory name from source path in "
               "the profile counter name for static functions."));
  
  static std::string getInstrProfErrString(instrprof_error Err) {
    switch (Err) {
    case instrprof_error::success:
      return "Success";
    case instrprof_error::eof:
      return "End of File";
    case instrprof_error::unrecognized_format:
      return "Unrecognized instrumentation profile encoding format";
    case instrprof_error::bad_magic:
      return "Invalid instrumentation profile data (bad magic)";
    case instrprof_error::bad_header:
      return "Invalid instrumentation profile data (file header is corrupt)";
    case instrprof_error::unsupported_version:
      return "Unsupported instrumentation profile format version";
    case instrprof_error::unsupported_hash_type:
      return "Unsupported instrumentation profile hash type";
    case instrprof_error::too_large:
      return "Too much profile data";
    case instrprof_error::truncated:
      return "Truncated profile data";
    case instrprof_error::malformed:
      return "Malformed instrumentation profile data";
    case instrprof_error::invalid_prof:
      return "Invalid profile created. Please file a bug "
             "at: " BUG_REPORT_URL
             " and include the profraw files that caused this error.";
    case instrprof_error::unknown_function:
      return "No profile data available for function";
    case instrprof_error::hash_mismatch:
      return "Function control flow change detected (hash mismatch)";
    case instrprof_error::count_mismatch:
      return "Function basic block count change detected (counter mismatch)";
    case instrprof_error::counter_overflow:
      return "Counter overflow";
    case instrprof_error::value_site_count_mismatch:
      return "Function value site count change detected (counter mismatch)";
    case instrprof_error::compress_failed:
      return "Failed to compress data (zlib)";
    case instrprof_error::uncompress_failed:
      return "Failed to uncompress data (zlib)";
    case instrprof_error::empty_raw_profile:
      return "Empty raw profile file";
    case instrprof_error::zlib_unavailable:
      return "Profile uses zlib compression but the profile reader was built without zlib support";
    }
    llvm_unreachable("A value of instrprof_error has no message.");
  }
  
  namespace {
  
  // FIXME: This class is only here to support the transition to llvm::Error. It
  // will be removed once this transition is complete. Clients should prefer to
  // deal with the Error value directly, rather than converting to error_code.
  class InstrProfErrorCategoryType : public std::error_category {
    const char *name() const noexcept override { return "llvm.instrprof"; }
  
    std::string message(int IE) const override {
      return getInstrProfErrString(static_cast<instrprof_error>(IE));
    }
  };
  
  } // end anonymous namespace
  
  static ManagedStatic<InstrProfErrorCategoryType> ErrorCategory;
  
  const std::error_category &llvm::instrprof_category() {
    return *ErrorCategory;
  }
  
  namespace {
  
  const char *InstrProfSectNameCommon[] = {
  #define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix)      \
    SectNameCommon,
  #include "llvm/ProfileData/InstrProfData.inc"
  };
  
  const char *InstrProfSectNameCoff[] = {
  #define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix)      \
    SectNameCoff,
  #include "llvm/ProfileData/InstrProfData.inc"
  };
  
  const char *InstrProfSectNamePrefix[] = {
  #define INSTR_PROF_SECT_ENTRY(Kind, SectNameCommon, SectNameCoff, Prefix)      \
    Prefix,
  #include "llvm/ProfileData/InstrProfData.inc"
  };
  
  } // namespace
  
  namespace llvm {
  
  cl::opt<bool> DoInstrProfNameCompression(
      "enable-name-compression",
      cl::desc("Enable name/filename string compression"), cl::init(true));
  
  std::string getInstrProfSectionName(InstrProfSectKind IPSK,
                                      Triple::ObjectFormatType OF,
                                      bool AddSegmentInfo) {
    std::string SectName;
  
    if (OF == Triple::MachO && AddSegmentInfo)
      SectName = InstrProfSectNamePrefix[IPSK];
  
    if (OF == Triple::COFF)
      SectName += InstrProfSectNameCoff[IPSK];
    else
      SectName += InstrProfSectNameCommon[IPSK];
  
    if (OF == Triple::MachO && IPSK == IPSK_data && AddSegmentInfo)
      SectName += ",regular,live_support";
  
    return SectName;
  }
  
  void SoftInstrProfErrors::addError(instrprof_error IE) {
    if (IE == instrprof_error::success)
      return;
  
    if (FirstError == instrprof_error::success)
      FirstError = IE;
  
    switch (IE) {
    case instrprof_error::hash_mismatch:
      ++NumHashMismatches;
      break;
    case instrprof_error::count_mismatch:
      ++NumCountMismatches;
      break;
    case instrprof_error::counter_overflow:
      ++NumCounterOverflows;
      break;
    case instrprof_error::value_site_count_mismatch:
      ++NumValueSiteCountMismatches;
      break;
    default:
      llvm_unreachable("Not a soft error");
    }
  }
  
  std::string InstrProfError::message() const {
    return getInstrProfErrString(Err);
  }
  
  char InstrProfError::ID = 0;
  
  std::string getPGOFuncName(StringRef RawFuncName,
                             GlobalValue::LinkageTypes Linkage,
                             StringRef FileName,
                             uint64_t Version LLVM_ATTRIBUTE_UNUSED) {
    return GlobalValue::getGlobalIdentifier(RawFuncName, Linkage, FileName);
  }
  
  // Strip NumPrefix level of directory name from PathNameStr. If the number of
  // directory separators is less than NumPrefix, strip all the directories and
  // leave base file name only.
  static StringRef stripDirPrefix(StringRef PathNameStr, uint32_t NumPrefix) {
    uint32_t Count = NumPrefix;
    uint32_t Pos = 0, LastPos = 0;
    for (auto & CI : PathNameStr) {
      ++Pos;
      if (llvm::sys::path::is_separator(CI)) {
        LastPos = Pos;
        --Count;
      }
      if (Count == 0)
        break;
    }
    return PathNameStr.substr(LastPos);
  }
  
  // Return the PGOFuncName. This function has some special handling when called
  // in LTO optimization. The following only applies when calling in LTO passes
  // (when \c InLTO is true): LTO's internalization privatizes many global linkage
  // symbols. This happens after value profile annotation, but those internal
  // linkage functions should not have a source prefix.
  // Additionally, for ThinLTO mode, exported internal functions are promoted
  // and renamed. We need to ensure that the original internal PGO name is
  // used when computing the GUID that is compared against the profiled GUIDs.
  // To differentiate compiler generated internal symbols from original ones,
  // PGOFuncName meta data are created and attached to the original internal
  // symbols in the value profile annotation step
  // (PGOUseFunc::annotateIndirectCallSites). If a symbol does not have the meta
  // data, its original linkage must be non-internal.
  std::string getPGOFuncName(const Function &F, bool InLTO, uint64_t Version) {
    if (!InLTO) {
      StringRef FileName(F.getParent()->getSourceFileName());
      uint32_t StripLevel = StaticFuncFullModulePrefix ? 0 : (uint32_t)-1;
      if (StripLevel < StaticFuncStripDirNamePrefix)
        StripLevel = StaticFuncStripDirNamePrefix;
      if (StripLevel)
        FileName = stripDirPrefix(FileName, StripLevel);
      return getPGOFuncName(F.getName(), F.getLinkage(), FileName, Version);
    }
  
    // In LTO mode (when InLTO is true), first check if there is a meta data.
    if (MDNode *MD = getPGOFuncNameMetadata(F)) {
      StringRef S = cast<MDString>(MD->getOperand(0))->getString();
      return S.str();
    }
  
    // If there is no meta data, the function must be a global before the value
    // profile annotation pass. Its current linkage may be internal if it is
    // internalized in LTO mode.
    return getPGOFuncName(F.getName(), GlobalValue::ExternalLinkage, "");
  }
  
  StringRef getFuncNameWithoutPrefix(StringRef PGOFuncName, StringRef FileName) {
    if (FileName.empty())
      return PGOFuncName;
    // Drop the file name including ':'. See also getPGOFuncName.
    if (PGOFuncName.startswith(FileName))
      PGOFuncName = PGOFuncName.drop_front(FileName.size() + 1);
    return PGOFuncName;
  }
  
  // \p FuncName is the string used as profile lookup key for the function. A
  // symbol is created to hold the name. Return the legalized symbol name.
  std::string getPGOFuncNameVarName(StringRef FuncName,
                                    GlobalValue::LinkageTypes Linkage) {
    std::string VarName = std::string(getInstrProfNameVarPrefix());
    VarName += FuncName;
  
    if (!GlobalValue::isLocalLinkage(Linkage))
      return VarName;
  
    // Now fix up illegal chars in local VarName that may upset the assembler.
    const char *InvalidChars = "-:<>/\"'";
    size_t found = VarName.find_first_of(InvalidChars);
    while (found != std::string::npos) {
      VarName[found] = '_';
      found = VarName.find_first_of(InvalidChars, found + 1);
    }
    return VarName;
  }
  
  GlobalVariable *createPGOFuncNameVar(Module &M,
                                       GlobalValue::LinkageTypes Linkage,
                                       StringRef PGOFuncName) {
    // We generally want to match the function's linkage, but available_externally
    // and extern_weak both have the wrong semantics, and anything that doesn't
    // need to link across compilation units doesn't need to be visible at all.
    if (Linkage == GlobalValue::ExternalWeakLinkage)
      Linkage = GlobalValue::LinkOnceAnyLinkage;
    else if (Linkage == GlobalValue::AvailableExternallyLinkage)
      Linkage = GlobalValue::LinkOnceODRLinkage;
    else if (Linkage == GlobalValue::InternalLinkage ||
             Linkage == GlobalValue::ExternalLinkage)
      Linkage = GlobalValue::PrivateLinkage;
  
    auto *Value =
        ConstantDataArray::getString(M.getContext(), PGOFuncName, false);
    auto FuncNameVar =
        new GlobalVariable(M, Value->getType(), true, Linkage, Value,
                           getPGOFuncNameVarName(PGOFuncName, Linkage));
  
    // Hide the symbol so that we correctly get a copy for each executable.
    if (!GlobalValue::isLocalLinkage(FuncNameVar->getLinkage()))
      FuncNameVar->setVisibility(GlobalValue::HiddenVisibility);
  
    return FuncNameVar;
  }
  
  GlobalVariable *createPGOFuncNameVar(Function &F, StringRef PGOFuncName) {
    return createPGOFuncNameVar(*F.getParent(), F.getLinkage(), PGOFuncName);
  }
  
  Error InstrProfSymtab::create(Module &M, bool InLTO) {
    for (Function &F : M) {
      // Function may not have a name: like using asm("") to overwrite the name.
      // Ignore in this case.
      if (!F.hasName())
        continue;
      const std::string &PGOFuncName = getPGOFuncName(F, InLTO);
      if (Error E = addFuncName(PGOFuncName))
        return E;
      MD5FuncMap.emplace_back(Function::getGUID(PGOFuncName), &F);
      // In ThinLTO, local function may have been promoted to global and have
      // suffix ".llvm." added to the function name. We need to add the
      // stripped function name to the symbol table so that we can find a match
      // from profile.
      //
      // We may have other suffixes similar as ".llvm." which are needed to
      // be stripped before the matching, but ".__uniq." suffix which is used
      // to differentiate internal linkage functions in different modules
      // should be kept. Now this is the only suffix with the pattern ".xxx"
      // which is kept before matching.
      const std::string UniqSuffix = ".__uniq.";
      auto pos = PGOFuncName.find(UniqSuffix);
      // Search '.' after ".__uniq." if ".__uniq." exists, otherwise
      // search '.' from the beginning.
      if (pos != std::string::npos)
        pos += UniqSuffix.length();
      else
        pos = 0;
      pos = PGOFuncName.find('.', pos);
      if (pos != std::string::npos && pos != 0) {
        const std::string &OtherFuncName = PGOFuncName.substr(0, pos);
        if (Error E = addFuncName(OtherFuncName))
          return E;
        MD5FuncMap.emplace_back(Function::getGUID(OtherFuncName), &F);
      }
    }
    Sorted = false;
    finalizeSymtab();
    return Error::success();
  }
  
  uint64_t InstrProfSymtab::getFunctionHashFromAddress(uint64_t Address) {
    finalizeSymtab();
    auto It = partition_point(AddrToMD5Map, [=](std::pair<uint64_t, uint64_t> A) {
      return A.first < Address;
    });
    // Raw function pointer collected by value profiler may be from
    // external functions that are not instrumented. They won't have
    // mapping data to be used by the deserializer. Force the value to
    // be 0 in this case.
    if (It != AddrToMD5Map.end() && It->first == Address)
      return (uint64_t)It->second;
    return 0;
  }
  
  Error collectPGOFuncNameStrings(ArrayRef<std::string> NameStrs,
                                  bool doCompression, std::string &Result) {
    assert(!NameStrs.empty() && "No name data to emit");
  
    uint8_t Header[16], *P = Header;
    std::string UncompressedNameStrings =
        join(NameStrs.begin(), NameStrs.end(), getInstrProfNameSeparator());
  
    assert(StringRef(UncompressedNameStrings)
                   .count(getInstrProfNameSeparator()) == (NameStrs.size() - 1) &&
           "PGO name is invalid (contains separator token)");
  
    unsigned EncLen = encodeULEB128(UncompressedNameStrings.length(), P);
    P += EncLen;
  
    auto WriteStringToResult = [&](size_t CompressedLen, StringRef InputStr) {
      EncLen = encodeULEB128(CompressedLen, P);
      P += EncLen;
      char *HeaderStr = reinterpret_cast<char *>(&Header[0]);
      unsigned HeaderLen = P - &Header[0];
      Result.append(HeaderStr, HeaderLen);
      Result += InputStr;
      return Error::success();
    };
  
    if (!doCompression) {
      return WriteStringToResult(0, UncompressedNameStrings);
    }
  
    SmallString<128> CompressedNameStrings;
    Error E = zlib::compress(StringRef(UncompressedNameStrings),
                             CompressedNameStrings, zlib::BestSizeCompression);
    if (E) {
      consumeError(std::move(E));
      return make_error<InstrProfError>(instrprof_error::compress_failed);
    }
  
    return WriteStringToResult(CompressedNameStrings.size(),
                               CompressedNameStrings);
  }
  
  StringRef getPGOFuncNameVarInitializer(GlobalVariable *NameVar) {
    auto *Arr = cast<ConstantDataArray>(NameVar->getInitializer());
    StringRef NameStr =
        Arr->isCString() ? Arr->getAsCString() : Arr->getAsString();
    return NameStr;
  }
  
  Error collectPGOFuncNameStrings(ArrayRef<GlobalVariable *> NameVars,
                                  std::string &Result, bool doCompression) {
    std::vector<std::string> NameStrs;
    for (auto *NameVar : NameVars) {
      NameStrs.push_back(std::string(getPGOFuncNameVarInitializer(NameVar)));
    }
    return collectPGOFuncNameStrings(
        NameStrs, zlib::isAvailable() && doCompression, Result);
  }
  
  Error readPGOFuncNameStrings(StringRef NameStrings, InstrProfSymtab &Symtab) {
    const uint8_t *P = NameStrings.bytes_begin();
    const uint8_t *EndP = NameStrings.bytes_end();
    while (P < EndP) {
      uint32_t N;
      uint64_t UncompressedSize = decodeULEB128(P, &N);
      P += N;
      uint64_t CompressedSize = decodeULEB128(P, &N);
      P += N;
      bool isCompressed = (CompressedSize != 0);
      SmallString<128> UncompressedNameStrings;
      StringRef NameStrings;
      if (isCompressed) {
        if (!llvm::zlib::isAvailable())
          return make_error<InstrProfError>(instrprof_error::zlib_unavailable);
  
        StringRef CompressedNameStrings(reinterpret_cast<const char *>(P),
                                        CompressedSize);
        if (Error E =
                zlib::uncompress(CompressedNameStrings, UncompressedNameStrings,
                                 UncompressedSize)) {
          consumeError(std::move(E));
          return make_error<InstrProfError>(instrprof_error::uncompress_failed);
        }
        P += CompressedSize;
        NameStrings = StringRef(UncompressedNameStrings.data(),
                                UncompressedNameStrings.size());
      } else {
        NameStrings =
            StringRef(reinterpret_cast<const char *>(P), UncompressedSize);
        P += UncompressedSize;
      }
      // Now parse the name strings.
      SmallVector<StringRef, 0> Names;
      NameStrings.split(Names, getInstrProfNameSeparator());
      for (StringRef &Name : Names)
        if (Error E = Symtab.addFuncName(Name))
          return E;
  
      while (P < EndP && *P == 0)
        P++;
    }
    return Error::success();
  }
  
  void InstrProfRecord::accumulateCounts(CountSumOrPercent &Sum) const {
    uint64_t FuncSum = 0;
    Sum.NumEntries += Counts.size();
    for (size_t F = 0, E = Counts.size(); F < E; ++F)
      FuncSum += Counts[F];
    Sum.CountSum += FuncSum;
  
    for (uint32_t VK = IPVK_First; VK <= IPVK_Last; ++VK) {
      uint64_t KindSum = 0;
      uint32_t NumValueSites = getNumValueSites(VK);
      for (size_t I = 0; I < NumValueSites; ++I) {
        uint32_t NV = getNumValueDataForSite(VK, I);
        std::unique_ptr<InstrProfValueData[]> VD = getValueForSite(VK, I);
        for (uint32_t V = 0; V < NV; V++)
          KindSum += VD[V].Count;
      }
      Sum.ValueCounts[VK] += KindSum;
    }
  }
  
  void InstrProfValueSiteRecord::overlap(InstrProfValueSiteRecord &Input,
                                         uint32_t ValueKind,
                                         OverlapStats &Overlap,
                                         OverlapStats &FuncLevelOverlap) {
    this->sortByTargetValues();
    Input.sortByTargetValues();
    double Score = 0.0f, FuncLevelScore = 0.0f;
    auto I = ValueData.begin();
    auto IE = ValueData.end();
    auto J = Input.ValueData.begin();
    auto JE = Input.ValueData.end();
    while (I != IE && J != JE) {
      if (I->Value == J->Value) {
        Score += OverlapStats::score(I->Count, J->Count,
                                     Overlap.Base.ValueCounts[ValueKind],
                                     Overlap.Test.ValueCounts[ValueKind]);
        FuncLevelScore += OverlapStats::score(
            I->Count, J->Count, FuncLevelOverlap.Base.ValueCounts[ValueKind],
            FuncLevelOverlap.Test.ValueCounts[ValueKind]);
        ++I;
      } else if (I->Value < J->Value) {
        ++I;
        continue;
      }
      ++J;
    }
    Overlap.Overlap.ValueCounts[ValueKind] += Score;
    FuncLevelOverlap.Overlap.ValueCounts[ValueKind] += FuncLevelScore;
  }
  
  // Return false on mismatch.
  void InstrProfRecord::overlapValueProfData(uint32_t ValueKind,
                                             InstrProfRecord &Other,
                                             OverlapStats &Overlap,
                                             OverlapStats &FuncLevelOverlap) {
    uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
    assert(ThisNumValueSites == Other.getNumValueSites(ValueKind));
    if (!ThisNumValueSites)
      return;
  
    std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
        getOrCreateValueSitesForKind(ValueKind);
    MutableArrayRef<InstrProfValueSiteRecord> OtherSiteRecords =
        Other.getValueSitesForKind(ValueKind);
    for (uint32_t I = 0; I < ThisNumValueSites; I++)
      ThisSiteRecords[I].overlap(OtherSiteRecords[I], ValueKind, Overlap,
                                 FuncLevelOverlap);
  }
  
  void InstrProfRecord::overlap(InstrProfRecord &Other, OverlapStats &Overlap,
                                OverlapStats &FuncLevelOverlap,
                                uint64_t ValueCutoff) {
    // FuncLevel CountSum for other should already computed and nonzero.
    assert(FuncLevelOverlap.Test.CountSum >= 1.0f);
    accumulateCounts(FuncLevelOverlap.Base);
    bool Mismatch = (Counts.size() != Other.Counts.size());
  
    // Check if the value profiles mismatch.
    if (!Mismatch) {
      for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind) {
        uint32_t ThisNumValueSites = getNumValueSites(Kind);
        uint32_t OtherNumValueSites = Other.getNumValueSites(Kind);
        if (ThisNumValueSites != OtherNumValueSites) {
          Mismatch = true;
          break;
        }
      }
    }
    if (Mismatch) {
      Overlap.addOneMismatch(FuncLevelOverlap.Test);
      return;
    }
  
    // Compute overlap for value counts.
    for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
      overlapValueProfData(Kind, Other, Overlap, FuncLevelOverlap);
  
    double Score = 0.0;
    uint64_t MaxCount = 0;
    // Compute overlap for edge counts.
    for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
      Score += OverlapStats::score(Counts[I], Other.Counts[I],
                                   Overlap.Base.CountSum, Overlap.Test.CountSum);
      MaxCount = std::max(Other.Counts[I], MaxCount);
    }
    Overlap.Overlap.CountSum += Score;
    Overlap.Overlap.NumEntries += 1;
  
    if (MaxCount >= ValueCutoff) {
      double FuncScore = 0.0;
      for (size_t I = 0, E = Other.Counts.size(); I < E; ++I)
        FuncScore += OverlapStats::score(Counts[I], Other.Counts[I],
                                         FuncLevelOverlap.Base.CountSum,
                                         FuncLevelOverlap.Test.CountSum);
      FuncLevelOverlap.Overlap.CountSum = FuncScore;
      FuncLevelOverlap.Overlap.NumEntries = Other.Counts.size();
      FuncLevelOverlap.Valid = true;
    }
  }
  
  void InstrProfValueSiteRecord::merge(InstrProfValueSiteRecord &Input,
                                       uint64_t Weight,
                                       function_ref<void(instrprof_error)> Warn) {
    this->sortByTargetValues();
    Input.sortByTargetValues();
    auto I = ValueData.begin();
    auto IE = ValueData.end();
    for (auto J = Input.ValueData.begin(), JE = Input.ValueData.end(); J != JE;
         ++J) {
      while (I != IE && I->Value < J->Value)
        ++I;
      if (I != IE && I->Value == J->Value) {
        bool Overflowed;
        I->Count = SaturatingMultiplyAdd(J->Count, Weight, I->Count, &Overflowed);
        if (Overflowed)
          Warn(instrprof_error::counter_overflow);
        ++I;
        continue;
      }
      ValueData.insert(I, *J);
    }
  }
  
  void InstrProfValueSiteRecord::scale(uint64_t N, uint64_t D,
                                       function_ref<void(instrprof_error)> Warn) {
    for (auto I = ValueData.begin(), IE = ValueData.end(); I != IE; ++I) {
      bool Overflowed;
      I->Count = SaturatingMultiply(I->Count, N, &Overflowed) / D;
      if (Overflowed)
        Warn(instrprof_error::counter_overflow);
    }
  }
  
  // Merge Value Profile data from Src record to this record for ValueKind.
  // Scale merged value counts by \p Weight.
  void InstrProfRecord::mergeValueProfData(
      uint32_t ValueKind, InstrProfRecord &Src, uint64_t Weight,
      function_ref<void(instrprof_error)> Warn) {
    uint32_t ThisNumValueSites = getNumValueSites(ValueKind);
    uint32_t OtherNumValueSites = Src.getNumValueSites(ValueKind);
    if (ThisNumValueSites != OtherNumValueSites) {
      Warn(instrprof_error::value_site_count_mismatch);
      return;
    }
    if (!ThisNumValueSites)
      return;
    std::vector<InstrProfValueSiteRecord> &ThisSiteRecords =
        getOrCreateValueSitesForKind(ValueKind);
    MutableArrayRef<InstrProfValueSiteRecord> OtherSiteRecords =
        Src.getValueSitesForKind(ValueKind);
    for (uint32_t I = 0; I < ThisNumValueSites; I++)
      ThisSiteRecords[I].merge(OtherSiteRecords[I], Weight, Warn);
  }
  
  void InstrProfRecord::merge(InstrProfRecord &Other, uint64_t Weight,
                              function_ref<void(instrprof_error)> Warn) {
    // If the number of counters doesn't match we either have bad data
    // or a hash collision.
    if (Counts.size() != Other.Counts.size()) {
      Warn(instrprof_error::count_mismatch);
      return;
    }
  
    for (size_t I = 0, E = Other.Counts.size(); I < E; ++I) {
      bool Overflowed;
      Counts[I] =
          SaturatingMultiplyAdd(Other.Counts[I], Weight, Counts[I], &Overflowed);
      if (Overflowed)
        Warn(instrprof_error::counter_overflow);
    }
  
    for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
      mergeValueProfData(Kind, Other, Weight, Warn);
  }
  
  void InstrProfRecord::scaleValueProfData(
      uint32_t ValueKind, uint64_t N, uint64_t D,
      function_ref<void(instrprof_error)> Warn) {
    for (auto &R : getValueSitesForKind(ValueKind))
      R.scale(N, D, Warn);
  }
  
  void InstrProfRecord::scale(uint64_t N, uint64_t D,
                              function_ref<void(instrprof_error)> Warn) {
    assert(D != 0 && "D cannot be 0");
    for (auto &Count : this->Counts) {
      bool Overflowed;
      Count = SaturatingMultiply(Count, N, &Overflowed) / D;
      if (Overflowed)
        Warn(instrprof_error::counter_overflow);
    }
    for (uint32_t Kind = IPVK_First; Kind <= IPVK_Last; ++Kind)
      scaleValueProfData(Kind, N, D, Warn);
  }
  
  // Map indirect call target name hash to name string.
  uint64_t InstrProfRecord::remapValue(uint64_t Value, uint32_t ValueKind,
                                       InstrProfSymtab *SymTab) {
    if (!SymTab)
      return Value;
  
    if (ValueKind == IPVK_IndirectCallTarget)
      return SymTab->getFunctionHashFromAddress(Value);
  
    return Value;
  }
  
  void InstrProfRecord::addValueData(uint32_t ValueKind, uint32_t Site,
                                     InstrProfValueData *VData, uint32_t N,
                                     InstrProfSymtab *ValueMap) {
    for (uint32_t I = 0; I < N; I++) {
      VData[I].Value = remapValue(VData[I].Value, ValueKind, ValueMap);
    }
    std::vector<InstrProfValueSiteRecord> &ValueSites =
        getOrCreateValueSitesForKind(ValueKind);
    if (N == 0)
      ValueSites.emplace_back();
    else
      ValueSites.emplace_back(VData, VData + N);
  }
  
  #define INSTR_PROF_COMMON_API_IMPL
  #include "llvm/ProfileData/InstrProfData.inc"
  
  /*!
   * ValueProfRecordClosure Interface implementation for  InstrProfRecord
   *  class. These C wrappers are used as adaptors so that C++ code can be
   *  invoked as callbacks.
   */
  uint32_t getNumValueKindsInstrProf(const void *Record) {
    return reinterpret_cast<const InstrProfRecord *>(Record)->getNumValueKinds();
  }
  
  uint32_t getNumValueSitesInstrProf(const void *Record, uint32_t VKind) {
    return reinterpret_cast<const InstrProfRecord *>(Record)
        ->getNumValueSites(VKind);
  }
  
  uint32_t getNumValueDataInstrProf(const void *Record, uint32_t VKind) {
    return reinterpret_cast<const InstrProfRecord *>(Record)
        ->getNumValueData(VKind);
  }
  
  uint32_t getNumValueDataForSiteInstrProf(const void *R, uint32_t VK,
                                           uint32_t S) {
    return reinterpret_cast<const InstrProfRecord *>(R)
        ->getNumValueDataForSite(VK, S);
  }
  
  void getValueForSiteInstrProf(const void *R, InstrProfValueData *Dst,
                                uint32_t K, uint32_t S) {
    reinterpret_cast<const InstrProfRecord *>(R)->getValueForSite(Dst, K, S);
  }
  
  ValueProfData *allocValueProfDataInstrProf(size_t TotalSizeInBytes) {
    ValueProfData *VD =
        (ValueProfData *)(new (::operator new(TotalSizeInBytes)) ValueProfData());
    memset(VD, 0, TotalSizeInBytes);
    return VD;
  }
  
  static ValueProfRecordClosure InstrProfRecordClosure = {
      nullptr,
      getNumValueKindsInstrProf,
      getNumValueSitesInstrProf,
      getNumValueDataInstrProf,
      getNumValueDataForSiteInstrProf,
      nullptr,
      getValueForSiteInstrProf,
      allocValueProfDataInstrProf};
  
  // Wrapper implementation using the closure mechanism.
  uint32_t ValueProfData::getSize(const InstrProfRecord &Record) {
    auto Closure = InstrProfRecordClosure;
    Closure.Record = &Record;
    return getValueProfDataSize(&Closure);
  }
  
  // Wrapper implementation using the closure mechanism.
  std::unique_ptr<ValueProfData>
  ValueProfData::serializeFrom(const InstrProfRecord &Record) {
    InstrProfRecordClosure.Record = &Record;
  
    std::unique_ptr<ValueProfData> VPD(
        serializeValueProfDataFrom(&InstrProfRecordClosure, nullptr));
    return VPD;
  }
  
  void ValueProfRecord::deserializeTo(InstrProfRecord &Record,
                                      InstrProfSymtab *SymTab) {
    Record.reserveSites(Kind, NumValueSites);
  
    InstrProfValueData *ValueData = getValueProfRecordValueData(this);
    for (uint64_t VSite = 0; VSite < NumValueSites; ++VSite) {
      uint8_t ValueDataCount = this->SiteCountArray[VSite];
      Record.addValueData(Kind, VSite, ValueData, ValueDataCount, SymTab);
      ValueData += ValueDataCount;
    }
  }
  
  // For writing/serializing,  Old is the host endianness, and  New is
  // byte order intended on disk. For Reading/deserialization, Old
  // is the on-disk source endianness, and New is the host endianness.
  void ValueProfRecord::swapBytes(support::endianness Old,
                                  support::endianness New) {
    using namespace support;
  
    if (Old == New)
      return;
  
    if (getHostEndianness() != Old) {
      sys::swapByteOrder<uint32_t>(NumValueSites);
      sys::swapByteOrder<uint32_t>(Kind);
    }
    uint32_t ND = getValueProfRecordNumValueData(this);
    InstrProfValueData *VD = getValueProfRecordValueData(this);
  
    // No need to swap byte array: SiteCountArrray.
    for (uint32_t I = 0; I < ND; I++) {
      sys::swapByteOrder<uint64_t>(VD[I].Value);
      sys::swapByteOrder<uint64_t>(VD[I].Count);
    }
    if (getHostEndianness() == Old) {
      sys::swapByteOrder<uint32_t>(NumValueSites);
      sys::swapByteOrder<uint32_t>(Kind);
    }
  }
  
  void ValueProfData::deserializeTo(InstrProfRecord &Record,
                                    InstrProfSymtab *SymTab) {
    if (NumValueKinds == 0)
      return;
  
    ValueProfRecord *VR = getFirstValueProfRecord(this);
    for (uint32_t K = 0; K < NumValueKinds; K++) {
      VR->deserializeTo(Record, SymTab);
      VR = getValueProfRecordNext(VR);
    }
  }
  
  template <class T>
  static T swapToHostOrder(const unsigned char *&D, support::endianness Orig) {
    using namespace support;
  
    if (Orig == little)
      return endian::readNext<T, little, unaligned>(D);
    else
      return endian::readNext<T, big, unaligned>(D);
  }
  
  static std::unique_ptr<ValueProfData> allocValueProfData(uint32_t TotalSize) {
    return std::unique_ptr<ValueProfData>(new (::operator new(TotalSize))
                                              ValueProfData());
  }
  
  Error ValueProfData::checkIntegrity() {
    if (NumValueKinds > IPVK_Last + 1)
      return make_error<InstrProfError>(instrprof_error::malformed);
    // Total size needs to be mulltiple of quadword size.
    if (TotalSize % sizeof(uint64_t))
      return make_error<InstrProfError>(instrprof_error::malformed);
  
    ValueProfRecord *VR = getFirstValueProfRecord(this);
    for (uint32_t K = 0; K < this->NumValueKinds; K++) {
      if (VR->Kind > IPVK_Last)
        return make_error<InstrProfError>(instrprof_error::malformed);
      VR = getValueProfRecordNext(VR);
      if ((char *)VR - (char *)this > (ptrdiff_t)TotalSize)
        return make_error<InstrProfError>(instrprof_error::malformed);
    }
    return Error::success();
  }
  
  Expected<std::unique_ptr<ValueProfData>>
  ValueProfData::getValueProfData(const unsigned char *D,
                                  const unsigned char *const BufferEnd,
                                  support::endianness Endianness) {
    using namespace support;
  
    if (D + sizeof(ValueProfData) > BufferEnd)
      return make_error<InstrProfError>(instrprof_error::truncated);
  
    const unsigned char *Header = D;
    uint32_t TotalSize = swapToHostOrder<uint32_t>(Header, Endianness);
    if (D + TotalSize > BufferEnd)
      return make_error<InstrProfError>(instrprof_error::too_large);
  
    std::unique_ptr<ValueProfData> VPD = allocValueProfData(TotalSize);
    memcpy(VPD.get(), D, TotalSize);
    // Byte swap.
    VPD->swapBytesToHost(Endianness);
  
    Error E = VPD->checkIntegrity();
    if (E)
      return std::move(E);
  
    return std::move(VPD);
  }
  
  void ValueProfData::swapBytesToHost(support::endianness Endianness) {
    using namespace support;
  
    if (Endianness == getHostEndianness())
      return;
  
    sys::swapByteOrder<uint32_t>(TotalSize);
    sys::swapByteOrder<uint32_t>(NumValueKinds);
  
    ValueProfRecord *VR = getFirstValueProfRecord(this);
    for (uint32_t K = 0; K < NumValueKinds; K++) {
      VR->swapBytes(Endianness, getHostEndianness());
      VR = getValueProfRecordNext(VR);
    }
  }
  
  void ValueProfData::swapBytesFromHost(support::endianness Endianness) {
    using namespace support;
  
    if (Endianness == getHostEndianness())
      return;
  
    ValueProfRecord *VR = getFirstValueProfRecord(this);
    for (uint32_t K = 0; K < NumValueKinds; K++) {
      ValueProfRecord *NVR = getValueProfRecordNext(VR);
      VR->swapBytes(getHostEndianness(), Endianness);
      VR = NVR;
    }
    sys::swapByteOrder<uint32_t>(TotalSize);
    sys::swapByteOrder<uint32_t>(NumValueKinds);
  }
  
  void annotateValueSite(Module &M, Instruction &Inst,
                         const InstrProfRecord &InstrProfR,
                         InstrProfValueKind ValueKind, uint32_t SiteIdx,
                         uint32_t MaxMDCount) {
    uint32_t NV = InstrProfR.getNumValueDataForSite(ValueKind, SiteIdx);
    if (!NV)
      return;
  
    uint64_t Sum = 0;
    std::unique_ptr<InstrProfValueData[]> VD =
        InstrProfR.getValueForSite(ValueKind, SiteIdx, &Sum);
  
    ArrayRef<InstrProfValueData> VDs(VD.get(), NV);
    annotateValueSite(M, Inst, VDs, Sum, ValueKind, MaxMDCount);
  }
  
  void annotateValueSite(Module &M, Instruction &Inst,
                         ArrayRef<InstrProfValueData> VDs,
                         uint64_t Sum, InstrProfValueKind ValueKind,
                         uint32_t MaxMDCount) {
    LLVMContext &Ctx = M.getContext();
    MDBuilder MDHelper(Ctx);
    SmallVector<Metadata *, 3> Vals;
    // Tag
    Vals.push_back(MDHelper.createString("VP"));
    // Value Kind
    Vals.push_back(MDHelper.createConstant(
        ConstantInt::get(Type::getInt32Ty(Ctx), ValueKind)));
    // Total Count
    Vals.push_back(
        MDHelper.createConstant(ConstantInt::get(Type::getInt64Ty(Ctx), Sum)));
  
    // Value Profile Data
    uint32_t MDCount = MaxMDCount;
    for (auto &VD : VDs) {
      Vals.push_back(MDHelper.createConstant(
          ConstantInt::get(Type::getInt64Ty(Ctx), VD.Value)));
      Vals.push_back(MDHelper.createConstant(
          ConstantInt::get(Type::getInt64Ty(Ctx), VD.Count)));
      if (--MDCount == 0)
        break;
    }
    Inst.setMetadata(LLVMContext::MD_prof, MDNode::get(Ctx, Vals));
  }
  
  bool getValueProfDataFromInst(const Instruction &Inst,
                                InstrProfValueKind ValueKind,
                                uint32_t MaxNumValueData,
                                InstrProfValueData ValueData[],
                                uint32_t &ActualNumValueData, uint64_t &TotalC,
                                bool GetNoICPValue) {
    MDNode *MD = Inst.getMetadata(LLVMContext::MD_prof);
    if (!MD)
      return false;
  
    unsigned NOps = MD->getNumOperands();
  
    if (NOps < 5)
      return false;
  
    // Operand 0 is a string tag "VP":
    MDString *Tag = cast<MDString>(MD->getOperand(0));
    if (!Tag)
      return false;
  
    if (!Tag->getString().equals("VP"))
      return false;
  
    // Now check kind:
    ConstantInt *KindInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(1));
    if (!KindInt)
      return false;
    if (KindInt->getZExtValue() != ValueKind)
      return false;
  
    // Get total count
    ConstantInt *TotalCInt = mdconst::dyn_extract<ConstantInt>(MD->getOperand(2));
    if (!TotalCInt)
      return false;
    TotalC = TotalCInt->getZExtValue();
  
    ActualNumValueData = 0;
  
    for (unsigned I = 3; I < NOps; I += 2) {
      if (ActualNumValueData >= MaxNumValueData)
        break;
      ConstantInt *Value = mdconst::dyn_extract<ConstantInt>(MD->getOperand(I));
      ConstantInt *Count =
          mdconst::dyn_extract<ConstantInt>(MD->getOperand(I + 1));
      if (!Value || !Count)
        return false;
      uint64_t CntValue = Count->getZExtValue();
      if (!GetNoICPValue && (CntValue == NOMORE_ICP_MAGICNUM))
        continue;
      ValueData[ActualNumValueData].Value = Value->getZExtValue();
      ValueData[ActualNumValueData].Count = CntValue;
      ActualNumValueData++;
    }
    return true;
  }
  
  MDNode *getPGOFuncNameMetadata(const Function &F) {
    return F.getMetadata(getPGOFuncNameMetadataName());
  }
  
  void createPGOFuncNameMetadata(Function &F, StringRef PGOFuncName) {
    // Only for internal linkage functions.
    if (PGOFuncName == F.getName())
        return;
    // Don't create duplicated meta-data.
    if (getPGOFuncNameMetadata(F))
      return;
    LLVMContext &C = F.getContext();
    MDNode *N = MDNode::get(C, MDString::get(C, PGOFuncName));
    F.setMetadata(getPGOFuncNameMetadataName(), N);
  }
  
  bool needsComdatForCounter(const Function &F, const Module &M) {
    if (F.hasComdat())
      return true;
  
    if (!Triple(M.getTargetTriple()).supportsCOMDAT())
      return false;
  
    // See createPGOFuncNameVar for more details. To avoid link errors, profile
    // counters for function with available_externally linkage needs to be changed
    // to linkonce linkage. On ELF based systems, this leads to weak symbols to be
    // created. Without using comdat, duplicate entries won't be removed by the
    // linker leading to increased data segement size and raw profile size. Even
    // worse, since the referenced counter from profile per-function data object
    // will be resolved to the common strong definition, the profile counts for
    // available_externally functions will end up being duplicated in raw profile
    // data. This can result in distorted profile as the counts of those dups
    // will be accumulated by the profile merger.
    GlobalValue::LinkageTypes Linkage = F.getLinkage();
    if (Linkage != GlobalValue::ExternalWeakLinkage &&
        Linkage != GlobalValue::AvailableExternallyLinkage)
      return false;
  
    return true;
  }
  
  // Check if INSTR_PROF_RAW_VERSION_VAR is defined.
  bool isIRPGOFlagSet(const Module *M) {
    auto IRInstrVar =
        M->getNamedGlobal(INSTR_PROF_QUOTE(INSTR_PROF_RAW_VERSION_VAR));
    if (!IRInstrVar || IRInstrVar->isDeclaration() ||
        IRInstrVar->hasLocalLinkage())
      return false;
  
    // Check if the flag is set.
    if (!IRInstrVar->hasInitializer())
      return false;
  
    auto *InitVal = dyn_cast_or_null<ConstantInt>(IRInstrVar->getInitializer());
    if (!InitVal)
      return false;
    return (InitVal->getZExtValue() & VARIANT_MASK_IR_PROF) != 0;
  }
  
  // Check if we can safely rename this Comdat function.
  bool canRenameComdatFunc(const Function &F, bool CheckAddressTaken) {
    if (F.getName().empty())
      return false;
    if (!needsComdatForCounter(F, *(F.getParent())))
      return false;
    // Unsafe to rename the address-taken function (which can be used in
    // function comparison).
    if (CheckAddressTaken && F.hasAddressTaken())
      return false;
    // Only safe to do if this function may be discarded if it is not used
    // in the compilation unit.
    if (!GlobalValue::isDiscardableIfUnused(F.getLinkage()))
      return false;
  
    // For AvailableExternallyLinkage functions.
    if (!F.hasComdat()) {
      assert(F.getLinkage() == GlobalValue::AvailableExternallyLinkage);
      return true;
    }
    return true;
  }
  
  // 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.
  void createIRLevelProfileFlagVar(Module &M, bool IsCS,
                                   bool InstrEntryBBEnabled) {
    const StringRef VarName(INSTR_PROF_QUOTE(INSTR_PROF_RAW_VERSION_VAR));
    Type *IntTy64 = Type::getInt64Ty(M.getContext());
    uint64_t ProfileVersion = (INSTR_PROF_RAW_VERSION | VARIANT_MASK_IR_PROF);
    if (IsCS)
      ProfileVersion |= VARIANT_MASK_CSIR_PROF;
    if (InstrEntryBBEnabled)
      ProfileVersion |= VARIANT_MASK_INSTR_ENTRY;
    auto IRLevelVersionVariable = new GlobalVariable(
        M, IntTy64, true, GlobalValue::WeakAnyLinkage,
        Constant::getIntegerValue(IntTy64, APInt(64, ProfileVersion)), VarName);
    IRLevelVersionVariable->setVisibility(GlobalValue::DefaultVisibility);
    Triple TT(M.getTargetTriple());
    if (TT.supportsCOMDAT()) {
      IRLevelVersionVariable->setLinkage(GlobalValue::ExternalLinkage);
      IRLevelVersionVariable->setComdat(M.getOrInsertComdat(VarName));
    }
  }
  
  // Create the variable for the profile file name.
  void createProfileFileNameVar(Module &M, StringRef InstrProfileOutput) {
    if (InstrProfileOutput.empty())
      return;
    Constant *ProfileNameConst =
        ConstantDataArray::getString(M.getContext(), InstrProfileOutput, true);
    GlobalVariable *ProfileNameVar = new GlobalVariable(
        M, ProfileNameConst->getType(), true, GlobalValue::WeakAnyLinkage,
        ProfileNameConst, INSTR_PROF_QUOTE(INSTR_PROF_PROFILE_NAME_VAR));
    Triple TT(M.getTargetTriple());
    if (TT.supportsCOMDAT()) {
      ProfileNameVar->setLinkage(GlobalValue::ExternalLinkage);
      ProfileNameVar->setComdat(M.getOrInsertComdat(
          StringRef(INSTR_PROF_QUOTE(INSTR_PROF_PROFILE_NAME_VAR))));
    }
  }
  
  Error OverlapStats::accumulateCounts(const std::string &BaseFilename,
                                       const std::string &TestFilename,
                                       bool IsCS) {
    auto getProfileSum = [IsCS](const std::string &Filename,
                                CountSumOrPercent &Sum) -> Error {
      auto ReaderOrErr = InstrProfReader::create(Filename);
      if (Error E = ReaderOrErr.takeError()) {
        return E;
      }
      auto Reader = std::move(ReaderOrErr.get());
      Reader->accumulateCounts(Sum, IsCS);
      return Error::success();
    };
    auto Ret = getProfileSum(BaseFilename, Base);
    if (Ret)
      return Ret;
    Ret = getProfileSum(TestFilename, Test);
    if (Ret)
      return Ret;
    this->BaseFilename = &BaseFilename;
    this->TestFilename = &TestFilename;
    Valid = true;
    return Error::success();
  }
  
  void OverlapStats::addOneMismatch(const CountSumOrPercent &MismatchFunc) {
    Mismatch.NumEntries += 1;
    Mismatch.CountSum += MismatchFunc.CountSum / Test.CountSum;
    for (unsigned I = 0; I < IPVK_Last - IPVK_First + 1; I++) {
      if (Test.ValueCounts[I] >= 1.0f)
        Mismatch.ValueCounts[I] +=
            MismatchFunc.ValueCounts[I] / Test.ValueCounts[I];
    }
  }
  
  void OverlapStats::addOneUnique(const CountSumOrPercent &UniqueFunc) {
    Unique.NumEntries += 1;
    Unique.CountSum += UniqueFunc.CountSum / Test.CountSum;
    for (unsigned I = 0; I < IPVK_Last - IPVK_First + 1; I++) {
      if (Test.ValueCounts[I] >= 1.0f)
        Unique.ValueCounts[I] += UniqueFunc.ValueCounts[I] / Test.ValueCounts[I];
    }
  }
  
  void OverlapStats::dump(raw_fd_ostream &OS) const {
    if (!Valid)
      return;
  
    const char *EntryName =
        (Level == ProgramLevel ? "functions" : "edge counters");
    if (Level == ProgramLevel) {
      OS << "Profile overlap infomation for base_profile: " << *BaseFilename
         << " and test_profile: " << *TestFilename << "\nProgram level:\n";
    } else {
      OS << "Function level:\n"
         << "  Function: " << FuncName << " (Hash=" << FuncHash << ")\n";
    }
  
    OS << "  # of " << EntryName << " overlap: " << Overlap.NumEntries << "\n";
    if (Mismatch.NumEntries)
      OS << "  # of " << EntryName << " mismatch: " << Mismatch.NumEntries
         << "\n";
    if (Unique.NumEntries)
      OS << "  # of " << EntryName
         << " only in test_profile: " << Unique.NumEntries << "\n";
  
    OS << "  Edge profile overlap: " << format("%.3f%%", Overlap.CountSum * 100)
       << "\n";
    if (Mismatch.NumEntries)
      OS << "  Mismatched count percentage (Edge): "
         << format("%.3f%%", Mismatch.CountSum * 100) << "\n";
    if (Unique.NumEntries)
      OS << "  Percentage of Edge profile only in test_profile: "
         << format("%.3f%%", Unique.CountSum * 100) << "\n";
    OS << "  Edge profile base count sum: " << format("%.0f", Base.CountSum)
       << "\n"
       << "  Edge profile test count sum: " << format("%.0f", Test.CountSum)
       << "\n";
  
    for (unsigned I = 0; I < IPVK_Last - IPVK_First + 1; I++) {
      if (Base.ValueCounts[I] < 1.0f && Test.ValueCounts[I] < 1.0f)
        continue;
      char ProfileKindName[20];
      switch (I) {
      case IPVK_IndirectCallTarget:
        strncpy(ProfileKindName, "IndirectCall", 19);
        break;
      case IPVK_MemOPSize:
        strncpy(ProfileKindName, "MemOP", 19);
        break;
      default:
        snprintf(ProfileKindName, 19, "VP[%d]", I);
        break;
      }
      OS << "  " << ProfileKindName
         << " profile overlap: " << format("%.3f%%", Overlap.ValueCounts[I] * 100)
         << "\n";
      if (Mismatch.NumEntries)
        OS << "  Mismatched count percentage (" << ProfileKindName
           << "): " << format("%.3f%%", Mismatch.ValueCounts[I] * 100) << "\n";
      if (Unique.NumEntries)
        OS << "  Percentage of " << ProfileKindName
           << " profile only in test_profile: "
           << format("%.3f%%", Unique.ValueCounts[I] * 100) << "\n";
      OS << "  " << ProfileKindName
         << " profile base count sum: " << format("%.0f", Base.ValueCounts[I])
         << "\n"
         << "  " << ProfileKindName
         << " profile test count sum: " << format("%.0f", Test.ValueCounts[I])
         << "\n";
    }
  }
  
  } // end namespace llvm
  