[Inline][Remark][NFC] Optionally provide inline context to inline advisor.

[mingmingl]

Summary

This patch has no functional change, and is merely a preparation patch for main functional change.

• Use case of the context information is to annotate inline remark name with context information. See https://reviews.llvm.org/D125495 for use case, and how remark names change (flag gated).

• The added struct (InlineContext) and enum classes are for general inliner passes, not tied to inline-advisor.

[mingmingl]

Use a general struct name, and add entries for SampleProfileInliner, AlwaysInliner, MLInliner.

Method llvm::AnnotateInlinePassName is supposed to be callable by a general inliner (i.e., not limited to the inliner passes that use an instance of InlineAdvisor).

[davidxl]

LGTM (In the summary, make it clearer that this is the preparation patch (NFC) for main functional change.)

[mingmingl]

Update commit message to the same as Phabricator summary, and a minor comment change

from

/// NOTE pass name is annotated only when `--annotate-inline-phase` is true
 /// and inline advisor constructor provides InlineContext.

to

/// NOTE pass name is annotated only when inline advisor constructor provides InlineContext.

[mingmingl]

Upon reflection of static usage I realize there is a bug in this patch.

Fixed it in D126833

llvm/include/llvm/Analysis/InlineAdvisor.h

 ///
 /// - Development mode, for training new models.
 /// In this mode, we trade off runtime performance for flexibility. This mode
 /// requires the full C Tensorflow API library, and evaluates models
 /// dynamically. This mode also permits generating training logs, for offline
 /// training.
 enum class InliningAdvisorMode : int { Default, Release, Development };
 
+// Each entry represents an inline driver.
+enum class InlinePass : int {
+  AlwaysInliner,
+  CGSCCInliner,
+  EarlyInliner,
+  ModuleInliner,
+  MLInliner,
+  ReplayCGSCCInliner,
+  ReplaySampleProfileInliner,
+  SampleProfileInliner,
+};
+
+/// Provides context on when an inline advisor is constructed in the pipeline
+/// (e.g., link phase, inline driver).
+struct InlineContext {
+  ThinOrFullLTOPhase LTOPhase;
+
+  InlinePass Pass;
+};
+
+std::string AnnotateInlinePassName(InlineContext IC);
+
 class InlineAdvisor;
 /// Capture state between an inlining decision having had been made, and
 /// its impact being observable. When collecting model training data, this
 /// allows recording features/decisions/partial reward data sets.
 ///
 /// Derivations of this type are expected to be tightly coupled with their
 /// InliningAdvisors. The base type implements the minimal contractual
 /// obligations.
public:
   /// to prepare for a partial update, based on the optional SCC.
   virtual void onPassExit(LazyCallGraph::SCC *SCC = nullptr) {}
 
   /// Support for printer pass
   virtual void print(raw_ostream &OS) const {
     OS << "Unimplemented InlineAdvisor print\n";
   }
 
+  /// NOTE pass name is annotated only when inline advisor constructor provides InlineContext.
+  const char *getAnnotatedInlinePassName();
+
 protected:
-  InlineAdvisor(Module &M, FunctionAnalysisManager &FAM);
+  InlineAdvisor(Module &M, FunctionAnalysisManager &FAM,
+                Optional<InlineContext> IC = NoneType::None);
   virtual std::unique_ptr<InlineAdvice> getAdviceImpl(CallBase &CB) = 0;
   virtual std::unique_ptr<InlineAdvice> getMandatoryAdvice(CallBase &CB,
                                                            bool Advice);
 
   Module &M;
   FunctionAnalysisManager &FAM;
+  const Optional<InlineContext> IC;
   std::unique_ptr<ImportedFunctionsInliningStatistics> ImportedFunctionsStats;
 
   enum class MandatoryInliningKind { NotMandatory, Always, Never };
 
   static MandatoryInliningKind getMandatoryKind(CallBase &CB,
                                                 FunctionAnalysisManager &FAM,
                                                 OptimizationRemarkEmitter &ORE);
 

llvm/lib/Analysis/InlineAdvisor.cpp

if (IsInliningRecommended)
                       [&](OptimizationRemark &Remark) {
                         Remark << ": always inline attribute";
                       });
   }
 
   void recordUnsuccessfulInliningImpl(const InlineResult &Result) override {
     if (IsInliningRecommended)
       ORE.emit([&]() {
-        return OptimizationRemarkMissed(DEBUG_TYPE, "NotInlined", DLoc, Block)
+        return OptimizationRemarkMissed(Advisor->getAnnotatedInlinePassName(),
+                                        "NotInlined", DLoc, Block)
                << "'" << NV("Callee", Callee) << "' is not AlwaysInline into '"
                << NV("Caller", Caller)
                << "': " << NV("Reason", Result.getFailureReason());
       });
   }
 
   void recordUnattemptedInliningImpl() override {
     assert(!IsInliningRecommended && "Expected to attempt inlining");
   }
 };
 } // namespace
 
 void DefaultInlineAdvice::recordUnsuccessfulInliningImpl(
     const InlineResult &Result) {
   using namespace ore;
   llvm::setInlineRemark(*OriginalCB, std::string(Result.getFailureReason()) +
                                          "; " + inlineCostStr(*OIC));
   ORE.emit([&]() {
-    return OptimizationRemarkMissed(DEBUG_TYPE, "NotInlined", DLoc, Block)
+    return OptimizationRemarkMissed(Advisor->getAnnotatedInlinePassName(),
+                                    "NotInlined", DLoc, Block)
            << "'" << NV("Callee", Callee) << "' is not inlined into '"
            << NV("Caller", Caller)
            << "': " << NV("Reason", Result.getFailureReason());
   });
 }
 
 void DefaultInlineAdvice::recordInliningWithCalleeDeletedImpl() {
   if (EmitRemarks)
-    emitInlinedIntoBasedOnCost(ORE, DLoc, Block, *Callee, *Caller, *OIC);
+    emitInlinedIntoBasedOnCost(ORE, DLoc, Block, *Callee, *Caller, *OIC,
+                               /* ForProfileContext= */ false,
+                               Advisor->getAnnotatedInlinePassName());
 }
 
 void DefaultInlineAdvice::recordInliningImpl() {
   if (EmitRemarks)
-    emitInlinedIntoBasedOnCost(ORE, DLoc, Block, *Callee, *Caller, *OIC);
+    emitInlinedIntoBasedOnCost(ORE, DLoc, Block, *Callee, *Caller, *OIC,
+                               /* ForProfileContext= */ false,
+                               Advisor->getAnnotatedInlinePassName());
 }
 
 llvm::Optional<llvm::InlineCost> static getDefaultInlineAdvice(
     CallBase &CB, FunctionAnalysisManager &FAM, const InlineParams &Params) {
   Function &Caller = *CB.getCaller();
   ProfileSummaryInfo *PSI =
       FAM.getResult<ModuleAnalysisManagerFunctionProxy>(Caller)
           .getCachedResult<ProfileSummaryAnalysis>(
llvm::emitInlinedInto(
       [&](OptimizationRemark &Remark) {
         if (ForProfileContext)
           Remark << " to match profiling context";
         Remark << " with " << IC;
       },
       PassName);
 }
 
-InlineAdvisor::InlineAdvisor(Module &M, FunctionAnalysisManager &FAM)
-    : M(M), FAM(FAM) {
+InlineAdvisor::InlineAdvisor(Module &M, FunctionAnalysisManager &FAM,
+                             Optional<InlineContext> IC)
+    : M(M), FAM(FAM), IC(IC) {
   if (InlinerFunctionImportStats != InlinerFunctionImportStatsOpts::No) {
     ImportedFunctionsStats =
         std::make_unique<ImportedFunctionsInliningStatistics>();
     ImportedFunctionsStats->setModuleInfo(M);
   }
 }
 
 InlineAdvisor::~InlineAdvisor() {
   if (ImportedFunctionsStats) {
     assert(InlinerFunctionImportStats != InlinerFunctionImportStatsOpts::No);
     ImportedFunctionsStats->dump(InlinerFunctionImportStats ==
                                  InlinerFunctionImportStatsOpts::Verbose);
   }
 }
 
 std::unique_ptr<InlineAdvice> InlineAdvisor::getMandatoryAdvice(CallBase &CB,
                                                                 bool Advice) {
   return std::make_unique<MandatoryInlineAdvice>(this, CB, getCallerORE(CB),
                                                  Advice);
 }
 
+static inline const char *getLTOPhase(ThinOrFullLTOPhase LTOPhase) {
+  switch (LTOPhase) {
+  case (ThinOrFullLTOPhase::None):
+    return "main";
+  case (ThinOrFullLTOPhase::ThinLTOPreLink):
+  case (ThinOrFullLTOPhase::FullLTOPreLink):
+    return "prelink";
+  case (ThinOrFullLTOPhase::ThinLTOPostLink):
+  case (ThinOrFullLTOPhase::FullLTOPostLink):
+    return "postlink";
+  }
+  llvm_unreachable("unreachable");
+}
+
+static inline const char *getInlineAdvisorContext(InlinePass IP) {
+  switch (IP) {
+  case (InlinePass::AlwaysInliner):
+    return "always-inline";
+  case (InlinePass::CGSCCInliner):
+    return "cgscc-inline";
+  case (InlinePass::EarlyInliner):
+    return "early-inline";
+  case (InlinePass::MLInliner):
+    return "ml-inline";
+  case (InlinePass::ModuleInliner):
+    return "module-inline";
+  case (InlinePass::ReplayCGSCCInliner):
+    return "replay-cgscc-inline";
+  case (InlinePass::ReplaySampleProfileInliner):
+    return "replay-sample-profile-inline";
+  case (InlinePass::SampleProfileInliner):
+    return "sample-profile-inline";
+  }
+
+  llvm_unreachable("unreachable");
+}
+
+std::string llvm::AnnotateInlinePassName(InlineContext IC) {
+  return std::string(getLTOPhase(IC.LTOPhase)) + "-" +
+         std::string(getInlineAdvisorContext(IC.Pass));
+}
+
+const char *InlineAdvisor::getAnnotatedInlinePassName() {
+  if (!IC.hasValue())
+    return DEBUG_TYPE;
+
+  // IC is constant and initialized in constructor, so compute the annotated
+  // name only once.
+  static const std::string PassName =
+      llvm::AnnotateInlinePassName(IC.getValue());
+
+  return PassName.c_str();
+}
+
 InlineAdvisor::MandatoryInliningKind
 InlineAdvisor::getMandatoryKind(CallBase &CB, FunctionAnalysisManager &FAM,
                                 OptimizationRemarkEmitter &ORE) {
   auto &Callee = *CB.getCalledFunction();
 
   auto GetTLI = [&](Function &F) -> const TargetLibraryInfo & {
     return FAM.getResult<TargetLibraryAnalysis>(F);
   };