[BOLT] Expose external entry count for functions (#141674)

Record the number of function invocations from external code - code
outside the binary, which may include JIT code and DSOs. Accounting
external entry counts improves the fidelity of call graph flow 
conservation analysis.

Test Plan: updated shrinkwrapping.test

bolt/include/bolt/Core/BinaryFunction.h

@@ -388,6 +388,10 @@ private:
   /// The profile data for the number of times the function was executed.
   uint64_t ExecutionCount{COUNT_NO_PROFILE};
 
+  /// Profile data for the number of times this function was entered from
+  /// external code (DSO, JIT, etc).
+  uint64_t ExternEntryCount{0};
+
   /// Profile match ratio.
   float ProfileMatchRatio{0.0f};
 
@@ -1877,6 +1881,10 @@ public:
     return *this;
   }
 
+  /// Set the profile data for the number of times the function was entered from
+  /// external code (DSO/JIT).
+  void setExternEntryCount(uint64_t Count) { ExternEntryCount = Count; }
+
   /// Adjust execution count for the function by a given \p Count. The value
   /// \p Count will be subtracted from the current function count.
   ///
@@ -1904,6 +1912,10 @@ public:
   /// Return COUNT_NO_PROFILE if there's no profile info.
   uint64_t getExecutionCount() const { return ExecutionCount; }
 
+  /// Return the profile information about the number of times the function was
+  /// entered from external code (DSO/JIT).
+  uint64_t getExternEntryCount() const { return ExternEntryCount; }
+
   /// Return the raw profile information about the number of branch
   /// executions corresponding to this function.
   uint64_t getRawSampleCount() const { return RawSampleCount; }

bolt/include/bolt/Profile/DataReader.h

@@ -97,6 +97,9 @@ struct FuncBranchData {
   /// Total execution count for the function.
   int64_t ExecutionCount{0};
 
+  /// Total entry count from external code for the function.
+  uint64_t ExternEntryCount{0};
+
   /// Indicate if the data was used.
   bool Used{false};
 

bolt/include/bolt/Profile/ProfileYAMLMapping.h

@@ -206,6 +206,7 @@ struct BinaryFunctionProfile {
   uint32_t Id{0};
   llvm::yaml::Hex64 Hash{0};
   uint64_t ExecCount{0};
+  uint64_t ExternEntryCount{0};
   std::vector<BinaryBasicBlockProfile> Blocks;
   std::vector<InlineTreeNode> InlineTree;
   bool Used{false};
@@ -218,6 +219,7 @@ template <> struct MappingTraits<bolt::BinaryFunctionProfile> {
     YamlIO.mapRequired("fid", BFP.Id);
     YamlIO.mapRequired("hash", BFP.Hash);
     YamlIO.mapRequired("exec", BFP.ExecCount);
+    YamlIO.mapOptional("extern", BFP.ExternEntryCount, 0);
     YamlIO.mapRequired("nblocks", BFP.NumBasicBlocks);
     YamlIO.mapOptional("blocks", BFP.Blocks,
                        std::vector<bolt::BinaryBasicBlockProfile>());

bolt/lib/Core/BinaryFunction.cpp

@@ -471,6 +471,8 @@ void BinaryFunction::print(raw_ostream &OS, std::string Annotation) {
     OS << "\n  Sample Count: " << RawSampleCount;
     OS << "\n  Profile Acc : " << format("%.1f%%", ProfileMatchRatio * 100.0f);
   }
+  if (ExternEntryCount)
+    OS << "\n  Extern Entry Count: " << ExternEntryCount;
 
   if (opts::PrintDynoStats && !getLayout().block_empty()) {
     OS << '\n';

bolt/lib/Passes/ProfileQualityStats.cpp

@@ -532,6 +532,9 @@ void computeFlowMappings(const BinaryContext &BC, FlowInfo &TotalFlowMap) {
     std::vector<uint64_t> &MaxCountMap = TotalMaxCountMaps[FunctionNum];
     std::vector<uint64_t> &MinCountMap = TotalMinCountMaps[FunctionNum];
 
+    // Record external entry count into CallGraphIncomingFlows
+    CallGraphIncomingFlows[FunctionNum] += Function->getExternEntryCount();
+
     // Update MaxCountMap, MinCountMap, and CallGraphIncomingFlows
     auto recordCall = [&](const BinaryBasicBlock *SourceBB,
                           const MCSymbol *DestSymbol, uint64_t Count,

bolt/lib/Profile/DataAggregator.cpp

@@ -2255,6 +2255,7 @@ std::error_code DataAggregator::writeBATYAML(BinaryContext &BC,
       YamlBF.Id = BF->getFunctionNumber();
       YamlBF.Hash = BAT->getBFHash(FuncAddress);
       YamlBF.ExecCount = BF->getKnownExecutionCount();
+      YamlBF.ExternEntryCount = BF->getExternEntryCount();
       YamlBF.NumBasicBlocks = BAT->getNumBasicBlocks(FuncAddress);
       const BoltAddressTranslation::BBHashMapTy &BlockMap =
           BAT->getBBHashMap(FuncAddress);

bolt/lib/Profile/DataReader.cpp

@@ -85,6 +85,7 @@ void FuncBranchData::appendFrom(const FuncBranchData &FBD, uint64_t Offset) {
   }
   llvm::stable_sort(Data);
   ExecutionCount += FBD.ExecutionCount;
+  ExternEntryCount += FBD.ExternEntryCount;
   for (auto I = FBD.EntryData.begin(), E = FBD.EntryData.end(); I != E; ++I) {
     assert(I->To.Name == FBD.Name);
     auto NewElmt = EntryData.insert(EntryData.end(), *I);
@@ -269,6 +270,7 @@ Error DataReader::preprocessProfile(BinaryContext &BC) {
     if (FuncBranchData *FuncData = getBranchDataForNames(Function.getNames())) {
       setBranchData(Function, FuncData);
       Function.ExecutionCount = FuncData->ExecutionCount;
+      Function.ExternEntryCount = FuncData->ExternEntryCount;
       FuncData->Used = true;
     }
   }
@@ -419,6 +421,7 @@ void DataReader::matchProfileData(BinaryFunction &BF) {
       if (fetchProfileForOtherEntryPoints(BF)) {
         BF.ProfileMatchRatio = evaluateProfileData(BF, *FBD);
         BF.ExecutionCount = FBD->ExecutionCount;
+        BF.ExternEntryCount = FBD->ExternEntryCount;
         BF.RawSampleCount = FBD->getNumExecutedBranches();
       }
       return;
@@ -449,6 +452,7 @@ void DataReader::matchProfileData(BinaryFunction &BF) {
     setBranchData(BF, NewBranchData);
     NewBranchData->Used = true;
     BF.ExecutionCount = NewBranchData->ExecutionCount;
+    BF.ExternEntryCount = NewBranchData->ExternEntryCount;
     BF.ProfileMatchRatio = 1.0f;
     break;
   }
@@ -1190,6 +1194,8 @@ std::error_code DataReader::parse() {
     if (BI.To.IsSymbol && BI.To.Offset == 0) {
       I = GetOrCreateFuncEntry(BI.To.Name);
       I->second.ExecutionCount += BI.Branches;
+      if (!BI.From.IsSymbol)
+        I->second.ExternEntryCount += BI.Branches;
     }
   }
 

bolt/lib/Profile/YAMLProfileReader.cpp

@@ -176,6 +176,7 @@ bool YAMLProfileReader::parseFunctionProfile(
   uint64_t FunctionExecutionCount = 0;
 
   BF.setExecutionCount(YamlBF.ExecCount);
+  BF.setExternEntryCount(YamlBF.ExternEntryCount);
 
   uint64_t FuncRawBranchCount = 0;
   for (const yaml::bolt::BinaryBasicBlockProfile &YamlBB : YamlBF.Blocks)

bolt/lib/Profile/YAMLProfileWriter.cpp

@@ -226,6 +226,7 @@ YAMLProfileWriter::convert(const BinaryFunction &BF, bool UseDFS,
   YamlBF.Hash = BF.getHash();
   YamlBF.NumBasicBlocks = BF.size();
   YamlBF.ExecCount = BF.getKnownExecutionCount();
+  YamlBF.ExternEntryCount = BF.getExternEntryCount();
   DenseMap<const MCDecodedPseudoProbeInlineTree *, uint32_t> InlineTreeNodeId;
   if (PseudoProbeDecoder && BF.getGUID()) {
     std::tie(YamlBF.InlineTree, InlineTreeNodeId) =

bolt/test/X86/shrinkwrapping.test

@@ -8,6 +8,7 @@ REQUIRES: shell
 
 RUN: %clangxx %cxxflags -no-pie %S/Inputs/exc4sw.S -o %t.exe -Wl,-q
 RUN: llvm-bolt %t.exe -o %t --relocs --frame-opt=all \
+RUN:   --print-only=main --print-cfg \
 RUN:   --data=%p/Inputs/exc4sw.fdata --reorder-blocks=cache 2>&1 | \
 RUN:   FileCheck %s --check-prefix=CHECK-BOLT
 
@@ -19,6 +20,7 @@ RUN: llvm-objdump --dwarf=frames %t | grep -A20 -e \
 RUN:   `llvm-nm --numeric-sort %t | grep main | tail -n 1 | cut -f1 -d' ' | \
 RUN:    tail -c9` 2>&1 | FileCheck %s --check-prefix=CHECK-OUTPUT
 
+CHECK-BOLT: Extern Entry Count: 100
 CHECK-BOLT: Shrink wrapping moved 2 spills inserting load/stores and 0 spills inserting push/pops
 
 CHECK-INPUT:  DW_CFA_advance_loc: 2