Add a ProfileCount class to represent entry counts.

Summary:
The class wraps a uint64_t and an enum to represent the type of profile
count (real and synthetic) with some helper methods.

Reviewers: davidxl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D41883

llvm-svn: 322771

include/llvm/IR/Function.h

@@ -234,21 +234,53 @@ public:
         getContext(), AttributeList::FunctionIndex, Kind));
   }
 
+  enum ProfileCountType { PCT_Invalid, PCT_Real, PCT_Synthetic };
+
+  /// Class to represent profile counts.
+  ///
+  /// This class represents both real and synthetic profile counts.
+  class ProfileCount {
+  private:
+    uint64_t Count;
+    ProfileCountType PCT;
+    static ProfileCount Invalid;
+
+  public:
+    ProfileCount() : Count(-1), PCT(PCT_Invalid) {}
+    ProfileCount(uint64_t Count, ProfileCountType PCT)
+        : Count(Count), PCT(PCT) {}
+    bool hasValue() const { return PCT != PCT_Invalid; }
+    uint64_t getCount() const { return Count; }
+    ProfileCountType getType() const { return PCT; }
+    bool isSynthetic() const { return PCT == PCT_Synthetic; }
+    explicit operator bool() { return hasValue(); }
+    bool operator!() const { return !hasValue(); }
+    // Update the count retaining the same profile count type.
+    ProfileCount &setCount(uint64_t C) {
+      Count = C;
+      return *this;
+    }
+    static ProfileCount getInvalid() { return ProfileCount(-1, PCT_Invalid); }
+  };
+
   /// \brief Set the entry count for this function.
   ///
   /// Entry count is the number of times this function was executed based on
-  /// pgo data. \p Synthetic indicates the count is synthesized by analysis and
-  /// not from a profile run. \p Imports points to a set of GUIDs that needs to
+  /// pgo data. \p Imports points to a set of GUIDs that needs to
   /// be imported by the function for sample PGO, to enable the same inlines as
   /// the profiled optimized binary.
-  void setEntryCount(uint64_t Count, bool Synthetic = false,
+  void setEntryCount(ProfileCount Count,
+                     const DenseSet<GlobalValue::GUID> *Imports = nullptr);
+
+  /// A convenience wrapper for setting entry count
+  void setEntryCount(uint64_t Count, ProfileCountType Type = PCT_Real,
                      const DenseSet<GlobalValue::GUID> *Imports = nullptr);
 
   /// \brief Get the entry count for this function.
   ///
   /// Entry count is the number of times the function was executed based on
   /// pgo data.
-  Optional<uint64_t> getEntryCount() const;
+  ProfileCount getEntryCount() const;
 
   /// Return true if the function is annotated with profile data.
   ///

lib/Analysis/BlockFrequencyInfoImpl.cpp

@@ -567,7 +567,7 @@ BlockFrequencyInfoImplBase::getProfileCountFromFreq(const Function &F,
   if (!EntryCount)
     return None;
   // Use 128 bit APInt to do the arithmetic to avoid overflow.
-  APInt BlockCount(128, EntryCount.getValue());
+  APInt BlockCount(128, EntryCount.getCount());
   APInt BlockFreq(128, Freq);
   APInt EntryFreq(128, getEntryFreq());
   BlockCount *= BlockFreq;

lib/Analysis/ProfileSummaryInfo.cpp

@@ -112,7 +112,7 @@ bool ProfileSummaryInfo::isFunctionEntryHot(const Function *F) {
   // FIXME: The heuristic used below for determining hotness is based on
   // preliminary SPEC tuning for inliner. This will eventually be a
   // convenience method that calls isHotCount.
-  return FunctionCount && isHotCount(FunctionCount.getValue());
+  return FunctionCount && isHotCount(FunctionCount.getCount());
 }
 
 /// Returns true if the function contains hot code. This can include a hot
@@ -125,7 +125,7 @@ bool ProfileSummaryInfo::isFunctionHotInCallGraph(const Function *F,
   if (!F || !computeSummary())
     return false;
   if (auto FunctionCount = F->getEntryCount())
-    if (isHotCount(FunctionCount.getValue()))
+    if (isHotCount(FunctionCount.getCount()))
       return true;
 
   if (hasSampleProfile()) {
@@ -154,7 +154,7 @@ bool ProfileSummaryInfo::isFunctionColdInCallGraph(const Function *F,
   if (!F || !computeSummary())
     return false;
   if (auto FunctionCount = F->getEntryCount())
-    if (!isColdCount(FunctionCount.getValue()))
+    if (!isColdCount(FunctionCount.getCount()))
       return false;
 
   if (hasSampleProfile()) {
@@ -187,7 +187,7 @@ bool ProfileSummaryInfo::isFunctionEntryCold(const Function *F) {
   // FIXME: The heuristic used below for determining coldness is based on
   // preliminary SPEC tuning for inliner. This will eventually be a
   // convenience method that calls isHotCount.
-  return FunctionCount && isColdCount(FunctionCount.getValue());
+  return FunctionCount && isColdCount(FunctionCount.getCount());
 }
 
 /// Compute the hot and cold thresholds.

lib/IR/Function.cpp

@@ -56,6 +56,7 @@
 #include <string>
 
 using namespace llvm;
+using ProfileCount = Function::ProfileCount;
 
 // Explicit instantiations of SymbolTableListTraits since some of the methods
 // are not in the public header file...
@@ -1320,27 +1321,43 @@ void Function::setValueSubclassDataBit(unsigned Bit, bool On) {
     setValueSubclassData(getSubclassDataFromValue() & ~(1 << Bit));
 }
 
-void Function::setEntryCount(uint64_t Count, bool Synthetic,
+void Function::setEntryCount(ProfileCount Count,
                              const DenseSet<GlobalValue::GUID> *S) {
+  assert(Count.hasValue());
+#if !defined(NDEBUG)
+  auto PrevCount = getEntryCount();
+  assert(!PrevCount.hasValue() || PrevCount.getType() == Count.getType());
+#endif
   MDBuilder MDB(getContext());
-  setMetadata(LLVMContext::MD_prof,
-              MDB.createFunctionEntryCount(Count, Synthetic, S));
+  setMetadata(
+      LLVMContext::MD_prof,
+      MDB.createFunctionEntryCount(Count.getCount(), Count.isSynthetic(), S));
 }
 
-Optional<uint64_t> Function::getEntryCount() const {
+void Function::setEntryCount(uint64_t Count, Function::ProfileCountType Type,
+                             const DenseSet<GlobalValue::GUID> *Imports) {
+  setEntryCount(ProfileCount(Count, Type), Imports);
+}
+
+ProfileCount Function::getEntryCount() const {
   MDNode *MD = getMetadata(LLVMContext::MD_prof);
   if (MD && MD->getOperand(0))
-    if (MDString *MDS = dyn_cast<MDString>(MD->getOperand(0)))
+    if (MDString *MDS = dyn_cast<MDString>(MD->getOperand(0))) {
       if (MDS->getString().equals("function_entry_count")) {
         ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(1));
         uint64_t Count = CI->getValue().getZExtValue();
         // A value of -1 is used for SamplePGO when there were no samples.
         // Treat this the same as unknown.
         if (Count == (uint64_t)-1)
-          return None;
-        return Count;
+          return ProfileCount::getInvalid();
+        return ProfileCount(Count, PCT_Real);
+      } else if (MDS->getString().equals("synthetic_function_entry_count")) {
+        ConstantInt *CI = mdconst::extract<ConstantInt>(MD->getOperand(1));
+        uint64_t Count = CI->getValue().getZExtValue();
+        return ProfileCount(Count, PCT_Synthetic);
       }
-  return None;
+    }
+  return ProfileCount::getInvalid();
 }
 
 DenseSet<GlobalValue::GUID> Function::getImportGUIDs() const {

lib/Transforms/IPO/PartialInlining.cpp

@@ -1384,7 +1384,8 @@ bool PartialInlinerImpl::tryPartialInline(FunctionCloner &Cloner) {
   if (CalleeEntryCount)
     computeCallsiteToProfCountMap(Cloner.ClonedFunc, CallSiteToProfCountMap);
 
-  uint64_t CalleeEntryCountV = (CalleeEntryCount ? *CalleeEntryCount : 0);
+  uint64_t CalleeEntryCountV =
+      (CalleeEntryCount ? CalleeEntryCount.getCount() : 0);
 
   bool AnyInline = false;
   for (User *User : Users) {
@@ -1433,7 +1434,8 @@ bool PartialInlinerImpl::tryPartialInline(FunctionCloner &Cloner) {
   if (AnyInline) {
     Cloner.IsFunctionInlined = true;
     if (CalleeEntryCount)
-      Cloner.OrigFunc->setEntryCount(CalleeEntryCountV);
+      Cloner.OrigFunc->setEntryCount(
+          CalleeEntryCount.setCount(CalleeEntryCountV));
     auto &ORE = (*GetORE)(*Cloner.OrigFunc);
     ORE.emit([&]() {
       return OptimizationRemark(DEBUG_TYPE, "PartiallyInlined", Cloner.OrigFunc)

lib/Transforms/IPO/SampleProfile.cpp

@@ -85,7 +85,7 @@
 
 using namespace llvm;
 using namespace sampleprof;
-
+using ProfileCount = Function::ProfileCount;
 #define DEBUG_TYPE "sample-profile"
 
 // Command line option to specify the file to read samples from. This is
@@ -1467,7 +1467,9 @@ bool SampleProfileLoader::emitAnnotations(Function &F) {
     // Sets the GUIDs that are inlined in the profiled binary. This is used
     // for ThinLink to make correct liveness analysis, and also make the IR
     // match the profiled binary before annotation.
-    F.setEntryCount(Samples->getHeadSamples() + 1, false, &InlinedGUIDs);
+    F.setEntryCount(
+        ProfileCount(Samples->getHeadSamples() + 1, Function::PCT_Real),
+        &InlinedGUIDs);
 
     // Compute dominance and loop info needed for propagation.
     computeDominanceAndLoopInfo(F);
@@ -1587,7 +1589,7 @@ bool SampleProfileLoader::runOnFunction(Function &F, ModuleAnalysisManager *AM)
   // Initialize the entry count to -1, which will be treated conservatively
   // by getEntryCount as the same as unknown (None). If we have samples this
   // will be overwritten in emitAnnotations.
-  F.setEntryCount(-1);
+  F.setEntryCount(ProfileCount(-1, Function::PCT_Real));
   std::unique_ptr<OptimizationRemarkEmitter> OwnedORE;
   if (AM) {
     auto &FAM =

lib/Transforms/IPO/SyntheticCountsPropagation.cpp

@@ -41,6 +41,7 @@
 
 using namespace llvm;
 using Scaled64 = ScaledNumber<uint64_t>;
+using ProfileCount = Function::ProfileCount;
 
 #define DEBUG_TYPE "synthetic-counts-propagation"
 
@@ -121,7 +122,8 @@ PreservedAnalyses SyntheticCountsPropagation::run(Module &M,
 
   // Set the counts as metadata.
   for (auto Entry : Counts)
-    Entry.first->setEntryCount(Entry.second, true);
+    Entry.first->setEntryCount(
+        ProfileCount(Entry.second, Function::PCT_Synthetic));
 
   return PreservedAnalyses::all();
 }

lib/Transforms/Instrumentation/PGOInstrumentation.cpp

@@ -119,6 +119,7 @@
 #include <vector>
 
 using namespace llvm;
+using ProfileCount = Function::ProfileCount;
 
 #define DEBUG_TYPE "pgo-instrumentation"
 
@@ -1139,7 +1140,7 @@ void PGOUseFunc::populateCounters() {
   }
 #endif
   uint64_t FuncEntryCount = getBBInfo(&*F.begin()).CountValue;
-  F.setEntryCount(FuncEntryCount);
+  F.setEntryCount(ProfileCount(FuncEntryCount, Function::PCT_Real));
   uint64_t FuncMaxCount = FuncEntryCount;
   for (auto &BB : F) {
     auto BI = findBBInfo(&BB);

lib/Transforms/Utils/CodeExtractor.cpp

@@ -66,6 +66,7 @@
 #include <vector>
 
 using namespace llvm;
+using ProfileCount = Function::ProfileCount;
 
 #define DEBUG_TYPE "code-extractor"
 
@@ -1163,10 +1164,10 @@ Function *CodeExtractor::extractCodeRegion() {
 
   // Update the entry count of the function.
   if (BFI) {
-    Optional<uint64_t> EntryCount =
-        BFI->getProfileCountFromFreq(EntryFreq.getFrequency());
-    if (EntryCount.hasValue())
-      newFunction->setEntryCount(EntryCount.getValue());
+    auto Count = BFI->getProfileCountFromFreq(EntryFreq.getFrequency());
+    if (Count.hasValue())
+      newFunction->setEntryCount(
+          ProfileCount(Count.getValue(), Function::PCT_Real)); // FIXME
     BFI->setBlockFreq(codeReplacer, EntryFreq.getFrequency());
   }
 

lib/Transforms/Utils/InlineFunction.cpp

@@ -72,6 +72,7 @@
 #include <vector>
 
 using namespace llvm;
+using ProfileCount = Function::ProfileCount;
 
 static cl::opt<bool>
 EnableNoAliasConversion("enable-noalias-to-md-conversion", cl::init(true),
@@ -1431,29 +1432,29 @@ static void updateCallerBFI(BasicBlock *CallSiteBlock,
 
 /// Update the branch metadata for cloned call instructions.
 static void updateCallProfile(Function *Callee, const ValueToValueMapTy &VMap,
-                              const Optional<uint64_t> &CalleeEntryCount,
+                              const ProfileCount &CalleeEntryCount,
                               const Instruction *TheCall,
                               ProfileSummaryInfo *PSI,
                               BlockFrequencyInfo *CallerBFI) {
-  if (!CalleeEntryCount.hasValue() || CalleeEntryCount.getValue() < 1)
+  if (!CalleeEntryCount.hasValue() || CalleeEntryCount.isSynthetic() ||
+      CalleeEntryCount.getCount() < 1)
     return;
-  Optional<uint64_t> CallSiteCount =
-      PSI ? PSI->getProfileCount(TheCall, CallerBFI) : None;
+  auto CallSiteCount = PSI ? PSI->getProfileCount(TheCall, CallerBFI) : None;
   uint64_t CallCount =
       std::min(CallSiteCount.hasValue() ? CallSiteCount.getValue() : 0,
-               CalleeEntryCount.getValue());
+               CalleeEntryCount.getCount());
 
   for (auto const &Entry : VMap)
     if (isa<CallInst>(Entry.first))
       if (auto *CI = dyn_cast_or_null<CallInst>(Entry.second))
-        CI->updateProfWeight(CallCount, CalleeEntryCount.getValue());
+        CI->updateProfWeight(CallCount, CalleeEntryCount.getCount());
   for (BasicBlock &BB : *Callee)
     // No need to update the callsite if it is pruned during inlining.
     if (VMap.count(&BB))
       for (Instruction &I : BB)
         if (CallInst *CI = dyn_cast<CallInst>(&I))
-          CI->updateProfWeight(CalleeEntryCount.getValue() - CallCount,
-                               CalleeEntryCount.getValue());
+          CI->updateProfWeight(CalleeEntryCount.getCount() - CallCount,
+                               CalleeEntryCount.getCount());
 }
 
 /// Update the entry count of callee after inlining.
@@ -1467,18 +1468,19 @@ static void updateCalleeCount(BlockFrequencyInfo *CallerBFI, BasicBlock *CallBB,
   // callsite is M, the new callee count is set to N - M. M is estimated from
   // the caller's entry count, its entry block frequency and the block frequency
   // of the callsite.
-  Optional<uint64_t> CalleeCount = Callee->getEntryCount();
+  auto CalleeCount = Callee->getEntryCount();
   if (!CalleeCount.hasValue() || !PSI)
     return;
-  Optional<uint64_t> CallCount = PSI->getProfileCount(CallInst, CallerBFI);
+  auto CallCount = PSI->getProfileCount(CallInst, CallerBFI);
   if (!CallCount.hasValue())
     return;
   // Since CallSiteCount is an estimate, it could exceed the original callee
   // count and has to be set to 0.
-  if (CallCount.getValue() > CalleeCount.getValue())
-    Callee->setEntryCount(0);
+  if (CallCount.getValue() > CalleeCount.getCount())
+    CalleeCount.setCount(0);
   else
-    Callee->setEntryCount(CalleeCount.getValue() - CallCount.getValue());
+    CalleeCount.setCount(CalleeCount.getCount() - CallCount.getValue());
+  Callee->setEntryCount(CalleeCount);
 }
 
 /// This function inlines the called function into the basic block of the

unittests/IR/MetadataTest.cpp

@@ -2436,9 +2436,20 @@ TEST_F(FunctionAttachmentTest, Verifier) {
 TEST_F(FunctionAttachmentTest, EntryCount) {
   Function *F = getFunction("foo");
   EXPECT_FALSE(F->getEntryCount().hasValue());
-  F->setEntryCount(12304);
-  EXPECT_TRUE(F->getEntryCount().hasValue());
-  EXPECT_EQ(12304u, *F->getEntryCount());
+  F->setEntryCount(12304, Function::PCT_Real);
+  auto Count = F->getEntryCount();
+  EXPECT_TRUE(Count.hasValue());
+  EXPECT_EQ(12304u, Count.getCount());
+  EXPECT_EQ(Function::PCT_Real, Count.getType());
+
+  // Repeat the same for synthetic counts.
+  F = getFunction("bar");
+  EXPECT_FALSE(F->getEntryCount().hasValue());
+  F->setEntryCount(123, Function::PCT_Synthetic);
+  Count = F->getEntryCount();
+  EXPECT_TRUE(Count.hasValue());
+  EXPECT_EQ(123u, Count.getCount());
+  EXPECT_EQ(Function::PCT_Synthetic, Count.getType());
 }
 
 TEST_F(FunctionAttachmentTest, SubprogramAttachment) {