Revert "Detect the order and add a summary flag to the profile"

This reverts commit 28b0374.

Author: wlei-llvm

llvm/include/llvm/ProfileData/SampleProf.h

@@ -201,10 +201,6 @@ enum class SecProfSummaryFlags : uint32_t {
   /// SecFlagIsPreInlined means this profile contains ShouldBeInlined
   /// contexts thus this is CS preinliner computed.
   SecFlagIsPreInlined = (1 << 4),
-  /// SecFlagIsMixedProbeOrder means in a pseude-probe based profile, the
-  /// callsite and BB probe IDs are mixed and sorted in lexcial order instead of
-  /// the order that callsite probe IDs are always after the BB probe IDs.
-  SecFlagIsMixedProbeOrder = (1 << 5),
 };
 
 enum class SecFuncMetadataFlags : uint32_t {
@@ -470,7 +466,7 @@ struct SampleContextFrame {
   LineLocation Location;
 
   SampleContextFrame() : Location(0, 0) {}
-
+  
   SampleContextFrame(FunctionId Func, LineLocation Location)
       : Func(Func), Location(Location) {}
 
@@ -531,7 +527,7 @@ class SampleContext {
       : Func(Name), State(UnknownContext), Attributes(ContextNone) {
         assert(!Name.empty() && "Name is empty");
       }
-
+  
   SampleContext(FunctionId Func)
       : Func(Func), State(UnknownContext), Attributes(ContextNone) {}
 
@@ -1182,8 +1178,6 @@ class FunctionSamples {
 
   static bool ProfileIsProbeBased;
 
-  static bool ProfileIsMixedProbeOrder;
-
   static bool ProfileIsCS;
 
   static bool ProfileIsPreInlined;

llvm/include/llvm/ProfileData/SampleProfReader.h

@@ -525,9 +525,6 @@ class SampleProfileReader {
   /// \brief Whether samples are collected based on pseudo probes.
   bool ProfileIsProbeBased = false;
 
-  /// Whether profiles are in mixed BB and callsite probe order.
-  bool ProfileIsMixedProbeOrder = false;
-
   /// Whether function profiles are context-sensitive flat profiles.
   bool ProfileIsCS = false;
 

llvm/lib/ProfileData/SampleProf.cpp

@@ -41,7 +41,6 @@ static cl::opt<bool> GenerateMergedBaseProfiles(
 namespace llvm {
 namespace sampleprof {
 bool FunctionSamples::ProfileIsProbeBased = false;
-bool FunctionSamples::ProfileIsMixedProbeOrder = false;
 bool FunctionSamples::ProfileIsCS = false;
 bool FunctionSamples::ProfileIsPreInlined = false;
 bool FunctionSamples::UseMD5 = false;

llvm/lib/ProfileData/SampleProfReader.cpp

@@ -704,9 +704,6 @@ std::error_code SampleProfileReaderExtBinaryBase::readOneSection(
       FunctionSamples::ProfileIsPreInlined = ProfileIsPreInlined = true;
     if (hasSecFlag(Entry, SecProfSummaryFlags::SecFlagFSDiscriminator))
       FunctionSamples::ProfileIsFS = ProfileIsFS = true;
-    if (hasSecFlag(Entry, SecProfSummaryFlags::SecFlagIsMixedProbeOrder))
-      FunctionSamples::ProfileIsMixedProbeOrder = ProfileIsMixedProbeOrder =
-          true;
     break;
   case SecNameTable: {
     bool FixedLengthMD5 =
@@ -1372,8 +1369,6 @@ static std::string getSecFlagsStr(const SecHdrTableEntry &Entry) {
       Flags.append("preInlined,");
     if (hasSecFlag(Entry, SecProfSummaryFlags::SecFlagFSDiscriminator))
       Flags.append("fs-discriminator,");
-    if (hasSecFlag(Entry, SecProfSummaryFlags::SecFlagIsMixedProbeOrder))
-      Flags.append("mixed-probe-order,");
     break;
   case SecFuncOffsetTable:
     if (hasSecFlag(Entry, SecFuncOffsetFlags::SecFlagOrdered))

llvm/lib/ProfileData/SampleProfWriter.cpp

@@ -437,10 +437,6 @@ std::error_code SampleProfileWriterExtBinaryBase::writeOneSection(
     addSectionFlag(SecProfSummary, SecProfSummaryFlags::SecFlagIsPreInlined);
   if (Type == SecProfSummary && FunctionSamples::ProfileIsFS)
     addSectionFlag(SecProfSummary, SecProfSummaryFlags::SecFlagFSDiscriminator);
-  if (Type == SecProfSummary && FunctionSamples::ProfileIsProbeBased &&
-      FunctionSamples::ProfileIsMixedProbeOrder)
-    addSectionFlag(SecProfSummary,
-                   SecProfSummaryFlags::SecFlagIsMixedProbeOrder);
 
   uint64_t SectionStart = markSectionStart(Type, LayoutIdx);
   switch (Type) {

llvm/lib/Transforms/IPO/SampleProfile.cpp

@@ -1190,7 +1190,7 @@ void SampleProfileLoader::findExternalInlineCandidate(
         CalleeSample->getContext().hasAttribute(ContextShouldBeInlined);
     if (!PreInline && CalleeSample->getHeadSamplesEstimate() < Threshold)
       continue;
-
+    
     Function *Func = SymbolMap.lookup(CalleeSample->getFunction());
     // Add to the import list only when it's defined out of module.
     if (!Func || Func->isDeclaration())
@@ -2173,14 +2173,6 @@ bool SampleProfileLoader::doInitialization(Module &M,
                                                DS_Warning));
       return false;
     }
-
-    if (!FunctionSamples::ProfileIsMixedProbeOrder) {
-      const char *Msg =
-          "Pseudo-probe-based profile is on an old version ID order which "
-          "could cause profile mismatch(performance regression)";
-      Ctx.diagnose(DiagnosticInfoSampleProfile(M.getModuleIdentifier(), Msg,
-                                               DS_Warning));
-    }
   }
 
   if (ReportProfileStaleness || PersistProfileStaleness ||

llvm/tools/llvm-profgen/ProfileGenerator.cpp

@@ -513,66 +513,6 @@ ProfileGenerator::getTopLevelFunctionProfile(FunctionId FuncName) {
   return ProfileMap.Create(Context);
 }
 
-// Use a heuristic to determine probe order by checking callsite insertion
-// position relative to the BB probes. Sort all the BB probes is in a list, for
-// each calliste, compute "ratio = insert position / length of the list". For
-// the old order, the probe ids for BB should be all before(smaller than) the
-// probe ids for callsite, this ratio should be equal to or close to 1.
-bool checkProbeIDIsInMixedOrder(const SampleProfileMap &Profiles) {
-  // Use flattned profile to maximize the callsites in the profile.
-  SampleProfileMap flattenProfile;
-  ProfileConverter::flattenProfile(Profiles, flattenProfile);
-
-  uint32_t PossibleOldOrderNum = 0;
-  uint32_t PossibleNewOrderNum = 0;
-
-  for (const auto &I : flattenProfile) {
-    const FunctionSamples &FS = I.second;
-    // Skip small functions whose profile order are likely random.
-    if (FS.getBodySamples().size() < 10)
-      continue;
-
-    std::set<uint32_t> PossibleBBProbeIDs;
-    std::set<uint32_t> CallsiteIDs;
-    for (const auto &I : FS.getBodySamples()) {
-      if (I.second.getCallTargets().empty())
-        PossibleBBProbeIDs.insert(I.first.LineOffset);
-      else
-        CallsiteIDs.insert(I.first.LineOffset);
-    }
-
-    if (PossibleBBProbeIDs.empty() || CallsiteIDs.empty())
-      continue;
-
-    uint32_t DistanceToBeginSum = 0;
-    for (const auto &ID : CallsiteIDs)
-      DistanceToBeginSum += std::distance(PossibleBBProbeIDs.begin(),
-                                          PossibleBBProbeIDs.upper_bound(ID));
-    uint32_t LengthSum = PossibleBBProbeIDs.size() * CallsiteIDs.size();
-
-    // Note that PossibleBBProbeIDs could contains some callsite probe id, the
-    // ratio is not exactly 1 for the old order, hence use a smaller threshold
-    // to determine.
-    if ((float)DistanceToBeginSum / LengthSum > 0.8)
-      PossibleOldOrderNum++;
-    else
-      PossibleNewOrderNum++;
-  }
-  return PossibleNewOrderNum >= PossibleOldOrderNum;
-}
-
-void warnOrWriteProbeOrderFlag(const SampleProfileMap &Profiles) {
-  if (FunctionSamples::ProfileIsProbeBased) {
-    FunctionSamples::ProfileIsMixedProbeOrder = true;
-    if (!checkProbeIDIsInMixedOrder(Profiles)) {
-      WithColor::warning()
-          << "Pseudo-probe-based profile is on an old version ID order which "
-             "could cause profile mismatch(performance regression)\n";
-      FunctionSamples::ProfileIsMixedProbeOrder = false;
-    }
-  }
-}
-
 void ProfileGenerator::generateProfile() {
   collectProfiledFunctions();
 
@@ -595,7 +535,6 @@ void ProfileGenerator::postProcessProfiles() {
   trimColdProfiles(ProfileMap, ColdCountThreshold);
   filterAmbiguousProfile(ProfileMap);
   calculateAndShowDensity(ProfileMap);
-  warnOrWriteProbeOrderFlag(ProfileMap);
 }
 
 void ProfileGenerator::trimColdProfiles(const SampleProfileMap &Profiles,
@@ -1129,7 +1068,6 @@ void CSProfileGenerator::postProcessProfiles() {
     FunctionSamples::ProfileIsCS = false;
   }
   filterAmbiguousProfile(ProfileMap);
-  warnOrWriteProbeOrderFlag(ProfileMap);
 }
 
 void ProfileGeneratorBase::computeSummaryAndThreshold(