SamplePGO ThinLTO ICP fix for local functions.

[danielcdh]

Summary

In SamplePGO, if the profile is collected from non-LTO binary, and used to drive ThinLTO, the indirect call promotion may fail because ThinLTO adjusts local function names to avoid conflicts. There are two places of where the mismatch can happen:

1. thin-link prepends SourceFileName to front of FuncName to build the GUID (GlobalValue::getGlobalIdentifier). Unlike instrumentation FDO, SamplePGO does not use the PGOFuncName scheme and therefore the indirect call target profile data contains a hash of the OriginalName.
2. backend compiler promotes some local functions to global and appends .llvm.{$ModuleHash} to the end of the FuncName to derive PromotedFunctionName

This patch tries at the best effort to find the GUID from the original local function name (in profile), and use that in ICP promotion, and in SamplePGO matching that happens in the backend after importing/inlining:

1. in thin-link, it builds the map from OriginalName to GUID so that when thin-link reads in indirect call target profile (represented by OriginalName), it knows which GUID to import.
2. in backend compiler, if sample profile reader cannot find a profile match for PromotedFunctionName, it will try to find if there is a match for OriginalFunctionName.
3. in backend compiler, we build symbol table entry for OriginalFunctionName and pointer to the same symbol of PromotedFunctionName, so that ICP can find the correct target to promote.

[tejohnson]

In SamplePGO, if the profile is collected from non-LTO binary, and used to drive ThinLTO, the indirect call promotion may fail because the function name will mismatch as ThinLTO added module ID in the local function name. This patch tries at the best effort to find the GUID from the unpromoted local function name (in profile), and use that in ICP promotion.

Want to clarify what the situation is that we're trying to fix here. The function name used to compute the GUID in the index for ThinLTO for functions with local linkage is 'SourceFilePath + ":" + FunctionName'. I'm not sure how collecting on a non-LTO binary matters here. Note that ThinLTO will sometimes promote local functions to global scope and rename them, but that is a completely different naming scheme, and is done in the ThinLTO Backends ('FunctionName + ".llvm." + ModuleHash').

Normally the PGOFunctionName used in profiles for indirect call targets (at least with instrumentation FDO) is the same 'SourceFilePath + ":" + FunctionName'., so the GUID computed for ThinLTO is the same as the GUID in the profile metadata for the hot targets. Is that not the case for AutoFDO indirect call targets?

[tejohnson]

Thanks for updating the description, it makes more sense now. A few wording suggestions below, and comments on the code following that.

In SamplePGO, if the profile is collected from non-LTO binary, and used to drive ThinLTO, the indirect call promotion may fail because the function name will mismatch as ThinLTO added module ID in the local function name. There are two places of where the mismatch can happen:

As you note below it isn't really a single problem of adding a module ID. I would just change this to say that ThinLTO adjusts local function names to avoid conflicts.

1. thin-link appends SourceFileName to front of FuncName to build the GUID (GlobalValue::getGlobalIdentifier)

s/appends/prepends/. Also add the fact that unlike instrumentation FDO, SamplePGO does not use the PGOFuncName scheme and therefore the indirect call target profile data contains a hash of the OriginalName.

2. backend compiler promotes some local functions to global and appends .llvm.{$ModuleHash} to the end of the FuncName to derive UpdatedFunctionName

Clearer to call this PromotedFunctionName.

This patch tries at the best effort to find the GUID from the original local function name (in profile), and use that in ICP promotion:

(and in SamplePGO matching that happens in the backend after importing/inlining)

1. in thin-link, it builds the map from OriginalName to GUID so that when thin-link reads in indirect call target profile (represented by OriginalName), it knows which GUID to import.
2. in backend compiler, if sample profile reader cannot find a profile match for UpdatedFunctionName, it will try to find if there is a match for OriginalFunctionName.
3. in backend compiler, we build symbol table entry for OriginalFunctionName and pointer to the same symbol of UpdatedFunctionName, so that ICP can find the correct target to promote.

include/llvm/IR/ModuleSummaryIndex.h

564

The fact that ValueGUID may be modified should be documented. But I have a suggestion about this down in selectCallee where it is invoked.

include/llvm/ProfileData/SampleProfReader.h

288

Needs comment

lib/ProfileData/InstrProf.cpp

302

Needs comment.

lib/Transforms/IPO/FunctionImport.cpp

180

I think it would be better to detect whether we need to update the GUID in the caller, in computeImportForFunction, and explicitly update the GUID there near the start of the loop. It will make what is going on clearer. Also, there is at least one check done based on the GUID early in that loop (to see if it is already in the dest module), that should be done on the updated GUID.

test/Bitcode/thinlto-function-summary-originalnames.ll

17 ↗

(On Diff #91061)

Why do we need to emit these in the combined index? We have the mappings available via the COMBINED_ORIGINAL_NAME if we need to recreate the relationship.

test/Transforms/PGOProfile/thinlto_samplepgo_icp.ll

7

Maybe, "calls to static target functions..." (I assume the promotion you are referring to is the ICP on the call, not the promotion to global of the static function?).
I assume that the GUID in the value profile metadata is from the original name - add comment to that effect?

[danielcdh]

update

[tejohnson]

LGTM, with some suggestions on comments below.

include/llvm/ProfileData/SampleProfReader.h

287

Are they stripped, or just not yet promoted and renamed?

lib/Bitcode/Writer/BitcodeWriter.cpp

3706

Needs comment about how the call edge may have been added based on indirect call profiles, in which case if it was for SamplePGO it would have used the OriginalID for local functions.

lib/Transforms/IPO/FunctionImport.cpp

200

Similar comment required here.

test/Transforms/PGOProfile/thinlto_samplepgo_icp.ll

7

This one looks not done yet.

[danielcdh]

update

[danielcdh]

include/llvm/IR/ModuleSummaryIndex.h

573

I also added a call to addOriginalName here as it should be the same as the other instance.

include/llvm/ProfileData/SampleProfReader.h

287

They should be all stripped. As discussed offline, if they are not stripped, we need to have a reliable way to map the unstripped name back to IR, which is undesirable.

[tejohnson]

Still LGTM except the new comments don't seem quite right to me.

include/llvm/ProfileData/SampleProfReader.h

287

Ok, right.

lib/Bitcode/Writer/BitcodeWriter.cpp

3707

This is not the name stripping in the profile issue though. This is because the SamplePGO doesn't use the PGOFuncName scheme of computing the GUID based on "SourceFileName:FunctionName" for locals, right?

lib/Transforms/IPO/FunctionImport.cpp

202

Ditto

[danielcdh]

update comments

[tejohnson]

LGTM thanks!

include/llvm/IR/ModuleSummaryIndex.h

private:
   /// (either by the initializer of a global variable, or referenced
   /// from within a function). This does not include functions called, which
   /// are listed in the derived FunctionSummary object.
   std::vector<ValueInfo> RefEdgeList;
 
 protected:
   /// GlobalValueSummary constructor.
   GlobalValueSummary(SummaryKind K, GVFlags Flags, std::vector<ValueInfo> Refs)
-      : Kind(K), Flags(Flags), RefEdgeList(std::move(Refs)) {}
+      : Kind(K), Flags(Flags), OriginalName(0), RefEdgeList(std::move(Refs)) {}
 
 public:
   virtual ~GlobalValueSummary() = default;
 
   /// Returns the hash of the original name, it is identical to the GUID for
   /// externally visible symbols, but not for local ones.
   GlobalValue::GUID getOriginalName() { return OriginalName; }
 
private:
   /// Holds strings for combined index, mapping to the corresponding module ID.
   ModulePathStringTableTy ModulePathStringTable;
 
   /// Mapping from type identifiers to summary information for that type
   /// identifier.
   // FIXME: Add bitcode read/write support for this field.
   std::map<std::string, TypeIdSummary> TypeIdMap;
 
+  /// Mapping from original ID to GUID. If original ID can map to multiple
+  /// GUIDs, it will be mapped to 0.
+  std::map<GlobalValue::GUID, GlobalValue::GUID> OidGuidMap;
+
   // YAML I/O support.
   friend yaml::MappingTraits<ModuleSummaryIndex>;
 
 public:
   gvsummary_iterator begin() { return GlobalValueMap.begin(); }
   const_gvsummary_iterator begin() const { return GlobalValueMap.begin(); }
   gvsummary_iterator end() { return GlobalValueMap.end(); }
   const_gvsummary_iterator end() const { return GlobalValueMap.end(); }
public:
   }
 
   /// Get the list of global value summary objects for a given value GUID.
   const const_gvsummary_iterator
   findGlobalValueSummaryList(GlobalValue::GUID ValueGUID) const {
     return GlobalValueMap.find(ValueGUID);
   }
 
+  /// Return the GUID for \p OriginalId in the OidGuidMap.
+  GlobalValue::GUID getGUIDFromOriginalID(GlobalValue::GUID OriginalID) const {
+    const auto I = OidGuidMap.find(OriginalID);
+    return I == OidGuidMap.end() ? 0 : I->second;
+  }
+
   /// Add a global value summary for a value of the given name.
   void addGlobalValueSummary(StringRef ValueName,
                              std::unique_ptr<GlobalValueSummary> Summary) {
+    addOriginalName(GlobalValue::getGUID(ValueName),
+                    Summary->getOriginalName());
     GlobalValueMap[GlobalValue::getGUID(ValueName)].push_back(
         std::move(Summary));
   }
 
   /// Add a global value summary for a value of the given GUID.
   void addGlobalValueSummary(GlobalValue::GUID ValueGUID,
                              std::unique_ptr<GlobalValueSummary> Summary) {
+    addOriginalName(ValueGUID, Summary->getOriginalName());
     GlobalValueMap[ValueGUID].push_back(std::move(Summary));
   }
 
+  /// Add an original name for the value of the given GUID.
+  void addOriginalName(GlobalValue::GUID ValueGUID,
+                       GlobalValue::GUID OrigGUID) {
+    if (OrigGUID == 0 || ValueGUID == OrigGUID)
+      return;
+    if (OidGuidMap.count(OrigGUID) && OidGuidMap[OrigGUID] != ValueGUID)
+      OidGuidMap[OrigGUID] = 0;
+    else
+      OidGuidMap[OrigGUID] = ValueGUID;
+  }
+
   /// Find the summary for global \p GUID in module \p ModuleId, or nullptr if
   /// not found.
   GlobalValueSummary *findSummaryInModule(GlobalValue::GUID ValueGUID,
                                           StringRef ModuleId) const {
     auto CalleeInfoList = findGlobalValueSummaryList(ValueGUID);
     if (CalleeInfoList == end()) {
       return nullptr; // This function does not have a summary
     }

include/llvm/ProfileData/SampleProfReader.h

public:
   /// \brief Print the profile for \p FName on stream \p OS.
   void dumpFunctionProfile(StringRef FName, raw_ostream &OS = dbgs());
 
   /// \brief Print all the profiles on stream \p OS.
   void dump(raw_ostream &OS = dbgs());
 
   /// \brief Return the samples collected for function \p F.
   FunctionSamples *getSamplesFor(const Function &F) {
-    return &Profiles[F.getName()];
+    // The function name may have been updated by adding suffix. In sample
+    // profile, the function names are all stripped, so we need to strip
+    // the function name suffix before matching with profile.
+    if (Profiles.count(F.getName().split('.').first))
+      return &Profiles[(F.getName().split('.').first)];
+    return nullptr;
   }
 
   /// \brief Return all the profiles.
   StringMap<FunctionSamples> &getProfiles() { return Profiles; }
 
   /// \brief Report a parse error message.
   void reportError(int64_t LineNumber, Twine Msg) const {
     Ctx.diagnose(DiagnosticInfoSampleProfile(Buffer->getBufferIdentifier(),

lib/Bitcode/Reader/BitcodeReader.cpp

Error ModuleSummaryIndexBitcodeReader::parseEntireSummary(
   if (Version < 1 || Version > 3)
     return error("Invalid summary version " + Twine(Version) +
                  ", 1, 2 or 3 expected");
   Record.clear();
 
   // Keep around the last seen summary to be used when we see an optional
   // "OriginalName" attachement.
   GlobalValueSummary *LastSeenSummary = nullptr;
+  GlobalValue::GUID LastSeenGUID = 0;
   bool Combined = false;
 
   // We can expect to see any number of type ID information records before
   // each function summary records; these variables store the information
   // collected so far so that it can be used to create the summary object.
   std::vector<GlobalValue::GUID> PendingTypeTests;
   std::vector<FunctionSummary::VFuncId> PendingTypeTestAssumeVCalls,
       PendingTypeCheckedLoadVCalls;
case bitc::FS_COMBINED_PROFILE: {
           std::move(PendingTypeTestAssumeConstVCalls),
           std::move(PendingTypeCheckedLoadConstVCalls));
       PendingTypeTests.clear();
       PendingTypeTestAssumeVCalls.clear();
       PendingTypeCheckedLoadVCalls.clear();
       PendingTypeTestAssumeConstVCalls.clear();
       PendingTypeCheckedLoadConstVCalls.clear();
       LastSeenSummary = FS.get();
+      LastSeenGUID = GUID;
       FS->setModulePath(ModuleIdMap[ModuleId]);
       TheIndex.addGlobalValueSummary(GUID, std::move(FS));
       Combined = true;
       break;
     }
     // FS_COMBINED_ALIAS: [valueid, modid, flags, valueid]
     // Aliases must be emitted (and parsed) after all FS_COMBINED entries, as
     // they expect all aliasee summaries to be available.
case bitc::FS_COMBINED_ALIAS: {
       auto AliaseeGUID = getGUIDFromValueId(AliaseeValueId).first;
       auto AliaseeInModule =
           TheIndex.findSummaryInModule(AliaseeGUID, AS->modulePath());
       if (!AliaseeInModule)
         return error("Alias expects aliasee summary to be parsed");
       AS->setAliasee(AliaseeInModule);
 
       GlobalValue::GUID GUID = getGUIDFromValueId(ValueID).first;
+      LastSeenGUID = GUID;
       TheIndex.addGlobalValueSummary(GUID, std::move(AS));
       Combined = true;
       break;
     }
     // FS_COMBINED_GLOBALVAR_INIT_REFS: [valueid, modid, flags, n x valueid]
     case bitc::FS_COMBINED_GLOBALVAR_INIT_REFS: {
       unsigned ValueID = Record[0];
       uint64_t ModuleId = Record[1];
       uint64_t RawFlags = Record[2];
       auto Flags = getDecodedGVSummaryFlags(RawFlags, Version);
       std::vector<ValueInfo> Refs =
           makeRefList(ArrayRef<uint64_t>(Record).slice(3));
       auto FS = llvm::make_unique<GlobalVarSummary>(Flags, std::move(Refs));
       LastSeenSummary = FS.get();
       FS->setModulePath(ModuleIdMap[ModuleId]);
       GlobalValue::GUID GUID = getGUIDFromValueId(ValueID).first;
+      LastSeenGUID = GUID;
       TheIndex.addGlobalValueSummary(GUID, std::move(FS));
       Combined = true;
       break;
     }
     // FS_COMBINED_ORIGINAL_NAME: [original_name]
     case bitc::FS_COMBINED_ORIGINAL_NAME: {
       uint64_t OriginalName = Record[0];
       if (!LastSeenSummary)
         return error("Name attachment that does not follow a combined record");
       LastSeenSummary->setOriginalName(OriginalName);
+      TheIndex.addOriginalName(LastSeenGUID, OriginalName);
       // Reset the LastSeenSummary
       LastSeenSummary = nullptr;
+      LastSeenGUID = 0;
       break;
     }
     case bitc::FS_TYPE_TESTS: {
       assert(PendingTypeTests.empty());
       PendingTypeTests.insert(PendingTypeTests.end(), Record.begin(),
                               Record.end());
       break;
     }

lib/Bitcode/Writer/BitcodeWriter.cpp

for (auto &EI : FS->calls()) {
       HasProfileData |= EI.second.Hotness != CalleeInfo::HotnessType::Unknown;
       if (HasProfileData)
         break;
     }
 
     for (auto &EI : FS->calls()) {
       // If this GUID doesn't have a value id, it doesn't have a function
       // summary and we don't need to record any calls to it.
-      if (!hasValueId(EI.first.getGUID()))
+      GlobalValue::GUID GUID = EI.first.getGUID();
+      if (!hasValueId(GUID)) {
+        // For SamplePGO, the call targets for indirect local functions will
+        // have its name stripped thus GUID is the original. We try to find
+        // corresponding GUID from the Original ID for the matching.
+        GUID = Index.getGUIDFromOriginalID(GUID);
+        if (GUID == 0 || !hasValueId(GUID))
           continue;
-      NameVals.push_back(getValueId(EI.first.getGUID()));
+      }
+      NameVals.push_back(getValueId(GUID));
       if (HasProfileData)
         NameVals.push_back(static_cast<uint8_t>(EI.second.Hotness));
     }
 
     unsigned FSAbbrev = (HasProfileData ? FSCallsProfileAbbrev : FSCallsAbbrev);
     unsigned Code =
         (HasProfileData ? bitc::FS_COMBINED_PROFILE : bitc::FS_COMBINED);
 

lib/ProfileData/InstrProf.cpp

void 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);
     addFuncName(PGOFuncName);
     MD5FuncMap.emplace_back(Function::getGUID(PGOFuncName), &F);
+    // In ThinLTO, local function may have been promoted to global and have
+    // suffix 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.
+    if (InLTO) {
+      auto pos = PGOFuncName.find('.');
+      if (pos != std::string::npos) {
+        const std::string &OtherFuncName = PGOFuncName.substr(0, pos);
+        addFuncName(OtherFuncName);
+        MD5FuncMap.emplace_back(Function::getGUID(OtherFuncName), &F);
+      }
+    }
   }
 
   finalizeSymtab();
 }
 
 Error collectPGOFuncNameStrings(const std::vector<std::string> &NameStrs,
                                 bool doCompression, std::string &Result) {
   assert(!NameStrs.empty() && "No name data to emit");

lib/Transforms/IPO/FunctionImport.cpp

 /// null if there's no match.
 static const GlobalValueSummary *selectCallee(GlobalValue::GUID GUID,
                                               unsigned Threshold,
                                               const ModuleSummaryIndex &Index,
                                               StringRef CallerModulePath) {
   auto CalleeSummaryList = Index.findGlobalValueSummaryList(GUID);
   if (CalleeSummaryList == Index.end())
     return nullptr; // This function does not have a summary
   return selectCallee(Index, CalleeSummaryList->second, Threshold,
                       CallerModulePath);
 }
 
 using EdgeInfo = std::tuple<const FunctionSummary *, unsigned /* Threshold */,
                             GlobalValue::GUID>;
 
 /// Compute the list of functions to import for a given caller. Mark these
 /// imported functions and the symbols they reference in their source module as
 /// exported from their source module.
 static void computeImportForFunction(
     const FunctionSummary &Summary, const ModuleSummaryIndex &Index,
     const unsigned Threshold, const GVSummaryMapTy &DefinedGVSummaries,
     SmallVectorImpl<EdgeInfo> &Worklist,
     FunctionImporter::ImportMapTy &ImportList,
     StringMap<FunctionImporter::ExportSetTy> *ExportLists = nullptr) {
   for (auto &Edge : Summary.calls()) {
     auto GUID = Edge.first.getGUID();
     DEBUG(dbgs() << " edge -> " << GUID << " Threshold:" << Threshold << "\n");
 
+    if (Index.findGlobalValueSummaryList(GUID) == Index.end()) {
+      // For SamplePGO, the call targets for indirect local functions will
+      // have its name stripped thus GUID is the original. We try to find
+      // corresponding GUID from the Original ID for the matching.
+      GUID = Index.getGUIDFromOriginalID(GUID);
+      if (GUID == 0)
+        continue;
+    }
+
     if (DefinedGVSummaries.count(GUID)) {
       DEBUG(dbgs() << "ignored! Target already in destination module.\n");
       continue;
     }
 
     auto GetBonusMultiplier = [](CalleeInfo::HotnessType Hotness) -> float {
       if (Hotness == CalleeInfo::HotnessType::Hot)
         return ImportHotMultiplier;

lib/Transforms/IPO/SampleProfile.cpp

bool SampleProfileLoaderLegacyPass::runOnModule(Module &M) {
   // FIXME: pass in AssumptionCache correctly for the new pass manager.
   SampleLoader.setACT(&getAnalysis<AssumptionCacheTracker>());
   return SampleLoader.runOnModule(M);
 }
 
 bool SampleProfileLoader::runOnFunction(Function &F) {
   F.setEntryCount(0);
   Samples = Reader->getSamplesFor(F);
-  if (!Samples->empty())
+  if (Samples && !Samples->empty())
     return emitAnnotations(F);
   return false;
 }
 
 PreservedAnalyses SampleProfileLoaderPass::run(Module &M,
                                                ModuleAnalysisManager &AM) {
 
   SampleProfileLoader SampleLoader(SampleProfileFile);
 
   SampleLoader.doInitialization(M);
 
   if (!SampleLoader.runOnModule(M))
     return PreservedAnalyses::all();
 
   return PreservedAnalyses::none();
 }

test/Transforms/PGOProfile/Inputs/thinlto_samplepgo_icp.ll

+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@fptr = external local_unnamed_addr global void ()*, align 8
+
+; Function Attrs: norecurse nounwind uwtable
+define void @_Z6updatei(i32 %i) local_unnamed_addr #0 {
+entry:
+  store void ()* @_ZL3foov, void ()** @fptr, align 8
+  ret void
+}
+
+; Function Attrs: norecurse nounwind readnone uwtable
+define internal void @_ZL3foov() #1 {
+entry:
+  ret void
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3}
+!llvm.ident = !{!31}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 5.0.0 (trunk 297016)", isOptimized: true, runtimeVersion: 0, emissionKind: NoDebug, enums: !2)
+!1 = !DIFile(filename: "b.cc", directory: "/ssd/llvm/abc/small")
+!2 = !{}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!31 = !{!"clang version 5.0.0 (trunk 297016)"}

test/Transforms/PGOProfile/thinlto_samplepgo_icp.ll

+; Do setup work for all below tests: generate bitcode and combined index
+; RUN: opt -module-summary %s -o %t.bc
+; RUN: opt -module-summary %p/Inputs/thinlto_samplepgo_icp.ll -o %t2.bc
+; RUN: llvm-lto -thinlto -o %t3 %t.bc %t2.bc
+
+; Checks if calls to static target functions are properly imported and promoted
+; by ICP. Note that the GUID in the profile is from the oroginal name.
+; RUN: opt -function-import -summary-file %t3.thinlto.bc %t.bc -o %t4.bc -print-imports 2>&1 | FileCheck %s --check-prefix=IMPORTS
+; IMPORTS: Import _ZL3foov.llvm.0
+; RUN: opt %t4.bc -icp-lto -pgo-icall-prom -S -icp-count-threshold=1 | FileCheck %s --check-prefix=ICALL-PROM
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@fptr = local_unnamed_addr global void ()* null, align 8
+
+; Function Attrs: norecurse uwtable
+define i32 @main() local_unnamed_addr #0 !prof !34 {
+entry:
+  %0 = load void ()*, void ()** @fptr, align 8
+; ICALL-PROM:   br i1 %{{[0-9]+}}, label %if.true.direct_targ, label %if.false.orig_indirect
+  tail call void %0(), !prof !40
+  ret i32 0
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3,!4}
+!llvm.ident = !{!31}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus, file: !1, producer: "clang version 5.0.0 (trunk 297016)", isOptimized: true, runtimeVersion: 0, emissionKind: NoDebug, enums: !2)
+!1 = !DIFile(filename: "main.cc", directory: ".")
+!2 = !{}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = !{i32 1, !"ProfileSummary", !5}
+!5 = !{!6, !7, !8, !9, !10, !11, !12, !13}
+!6 = !{!"ProfileFormat", !"SampleProfile"}
+!7 = !{!"TotalCount", i64 3003}
+!8 = !{!"MaxCount", i64 3000}
+!9 = !{!"MaxInternalCount", i64 0}
+!10 = !{!"MaxFunctionCount", i64 0}
+!11 = !{!"NumCounts", i64 3}
+!12 = !{!"NumFunctions", i64 1}
+!13 = !{!"DetailedSummary", !14}
+!14 = !{!15, !16, !17, !18, !19, !20, !20, !21, !21, !22, !23, !24, !25, !26, !27, !28, !29, !30}
+!15 = !{i32 10000, i64 3000, i32 1}
+!16 = !{i32 100000, i64 3000, i32 1}
+!17 = !{i32 200000, i64 3000, i32 1}
+!18 = !{i32 300000, i64 3000, i32 1}
+!19 = !{i32 400000, i64 3000, i32 1}
+!20 = !{i32 500000, i64 3000, i32 1}
+!21 = !{i32 600000, i64 3000, i32 1}
+!22 = !{i32 700000, i64 3000, i32 1}
+!23 = !{i32 800000, i64 3000, i32 1}
+!24 = !{i32 900000, i64 3000, i32 1}
+!25 = !{i32 950000, i64 3000, i32 1}
+!26 = !{i32 990000, i64 3000, i32 1}
+!27 = !{i32 999000, i64 3000, i32 1}
+!28 = !{i32 999900, i64 2, i32 2}
+!29 = !{i32 999990, i64 2, i32 2}
+!30 = !{i32 999999, i64 2, i32 2}
+!31 = !{!"clang version 5.0.0 (trunk 297016)"}
+!34 = !{!"function_entry_count", i64 1}
+!40 = !{!"VP", i32 0, i64 3000, i64 -8789629626369651636, i64 3000}