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author | Mingming Liu <minglotus6@gmail.com> | 2024-05-19 22:43:55 -0700 |
---|---|---|
committer | GitHub <noreply@github.com> | 2024-05-19 22:43:55 -0700 |
commit | a122660b97848488c1108716c1aa63eb3835f6c6 (patch) | |
tree | 2d623ef8fcdb3a9c77ec05d106031ff1ffff6ffc | |
parent | 6b0733e3a35350679ea9c6056ecd28652d99017f (diff) | |
download | llvm-a122660b97848488c1108716c1aa63eb3835f6c6.zip llvm-a122660b97848488c1108716c1aa63eb3835f6c6.tar.gz llvm-a122660b97848488c1108716c1aa63eb3835f6c6.tar.bz2 |
Revert "Revert "[ThinLTO] Populate declaration import status except for distr…"revert-92715-revert-88024-users/minglotus-6/spr/summary2
This reverts commit 6b0733e3a35350679ea9c6056ecd28652d99017f.
-rw-r--r-- | llvm/include/llvm/IR/ModuleSummaryIndex.h | 7 | ||||
-rw-r--r-- | llvm/include/llvm/Transforms/IPO/FunctionImport.h | 15 | ||||
-rw-r--r-- | llvm/lib/LTO/LTO.cpp | 32 | ||||
-rw-r--r-- | llvm/lib/LTO/LTOBackend.cpp | 9 | ||||
-rw-r--r-- | llvm/lib/Transforms/IPO/FunctionImport.cpp | 270 | ||||
-rw-r--r-- | llvm/test/ThinLTO/X86/funcimport-stats.ll | 4 | ||||
-rw-r--r-- | llvm/test/ThinLTO/X86/import_callee_declaration.ll | 180 | ||||
-rw-r--r-- | llvm/test/Transforms/FunctionImport/funcimport.ll | 5 | ||||
-rw-r--r-- | llvm/tools/llvm-link/llvm-link.cpp | 6 |
9 files changed, 443 insertions, 85 deletions
diff --git a/llvm/include/llvm/IR/ModuleSummaryIndex.h b/llvm/include/llvm/IR/ModuleSummaryIndex.h index 5d137d4..a6bb261 100644 --- a/llvm/include/llvm/IR/ModuleSummaryIndex.h +++ b/llvm/include/llvm/IR/ModuleSummaryIndex.h @@ -587,6 +587,10 @@ public: void setImportKind(ImportKind IK) { Flags.ImportType = IK; } + GlobalValueSummary::ImportKind importType() const { + return static_cast<ImportKind>(Flags.ImportType); + } + GlobalValue::VisibilityTypes getVisibility() const { return (GlobalValue::VisibilityTypes)Flags.Visibility; } @@ -1272,6 +1276,9 @@ using ModulePathStringTableTy = StringMap<ModuleHash>; /// a particular module, and provide efficient access to their summary. using GVSummaryMapTy = DenseMap<GlobalValue::GUID, GlobalValueSummary *>; +/// A set of global value summary pointers. +using GVSummaryPtrSet = SmallPtrSet<GlobalValueSummary *, 4>; + /// Map of a type GUID to type id string and summary (multimap used /// in case of GUID conflicts). using TypeIdSummaryMapTy = diff --git a/llvm/include/llvm/Transforms/IPO/FunctionImport.h b/llvm/include/llvm/Transforms/IPO/FunctionImport.h index c4d19e8..024bba8 100644 --- a/llvm/include/llvm/Transforms/IPO/FunctionImport.h +++ b/llvm/include/llvm/Transforms/IPO/FunctionImport.h @@ -31,9 +31,9 @@ class Module; /// based on the provided summary informations. class FunctionImporter { public: - /// Set of functions to import from a source module. Each entry is a set - /// containing all the GUIDs of all functions to import for a source module. - using FunctionsToImportTy = std::unordered_set<GlobalValue::GUID>; + /// The functions to import from a source module and their import type. + using FunctionsToImportTy = + DenseMap<GlobalValue::GUID, GlobalValueSummary::ImportKind>; /// The different reasons selectCallee will chose not to import a /// candidate. @@ -99,8 +99,13 @@ public: /// index's module path string table). using ImportMapTy = DenseMap<StringRef, FunctionsToImportTy>; - /// The set contains an entry for every global value the module exports. - using ExportSetTy = DenseSet<ValueInfo>; + /// The map contains an entry for every global value the module exports. + /// The key is ValueInfo, and the value indicates whether the definition + /// or declaration is visible to another module. If a function's definition is + /// visible to other modules, the global values this function referenced are + /// visible and shouldn't be internalized. + /// TODO: Rename to `ExportMapTy`. + using ExportSetTy = DenseMap<ValueInfo, GlobalValueSummary::ImportKind>; /// A function of this type is used to load modules referenced by the index. using ModuleLoaderTy = diff --git a/llvm/lib/LTO/LTO.cpp b/llvm/lib/LTO/LTO.cpp index 5c603ac..e2754d7 100644 --- a/llvm/lib/LTO/LTO.cpp +++ b/llvm/lib/LTO/LTO.cpp @@ -121,6 +121,9 @@ void llvm::computeLTOCacheKey( support::endian::write64le(Data, I); Hasher.update(Data); }; + auto AddUint8 = [&](const uint8_t I) { + Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&I, 1)); + }; AddString(Conf.CPU); // FIXME: Hash more of Options. For now all clients initialize Options from // command-line flags (which is unsupported in production), but may set @@ -156,18 +159,18 @@ void llvm::computeLTOCacheKey( auto ModHash = Index.getModuleHash(ModuleID); Hasher.update(ArrayRef<uint8_t>((uint8_t *)&ModHash[0], sizeof(ModHash))); - std::vector<uint64_t> ExportsGUID; + std::vector<std::pair<uint64_t, uint8_t>> ExportsGUID; ExportsGUID.reserve(ExportList.size()); - for (const auto &VI : ExportList) { - auto GUID = VI.getGUID(); - ExportsGUID.push_back(GUID); - } + for (const auto &[VI, ExportType] : ExportList) + ExportsGUID.push_back( + std::make_pair(VI.getGUID(), static_cast<uint8_t>(ExportType))); // Sort the export list elements GUIDs. llvm::sort(ExportsGUID); - for (uint64_t GUID : ExportsGUID) { + for (auto [GUID, ExportType] : ExportsGUID) { // The export list can impact the internalization, be conservative here Hasher.update(ArrayRef<uint8_t>((uint8_t *)&GUID, sizeof(GUID))); + AddUint8(ExportType); } // Include the hash for every module we import functions from. The set of @@ -199,7 +202,7 @@ void llvm::computeLTOCacheKey( [](const ImportModule &Lhs, const ImportModule &Rhs) -> bool { return Lhs.getHash() < Rhs.getHash(); }); - std::vector<uint64_t> ImportedGUIDs; + std::vector<std::pair<uint64_t, uint8_t>> ImportedGUIDs; for (const ImportModule &Entry : ImportModulesVector) { auto ModHash = Entry.getHash(); Hasher.update(ArrayRef<uint8_t>((uint8_t *)&ModHash[0], sizeof(ModHash))); @@ -207,11 +210,13 @@ void llvm::computeLTOCacheKey( AddUint64(Entry.getFunctions().size()); ImportedGUIDs.clear(); - for (auto &Fn : Entry.getFunctions()) - ImportedGUIDs.push_back(Fn); + for (auto &[Fn, ImportType] : Entry.getFunctions()) + ImportedGUIDs.push_back(std::make_pair(Fn, ImportType)); llvm::sort(ImportedGUIDs); - for (auto &GUID : ImportedGUIDs) + for (auto &[GUID, Type] : ImportedGUIDs) { AddUint64(GUID); + AddUint8(Type); + } } // Include the hash for the resolved ODR. @@ -281,9 +286,9 @@ void llvm::computeLTOCacheKey( // Imported functions may introduce new uses of type identifier resolutions, // so we need to collect their used resolutions as well. for (const ImportModule &ImpM : ImportModulesVector) - for (auto &ImpF : ImpM.getFunctions()) { + for (auto &[GUID, UnusedImportType] : ImpM.getFunctions()) { GlobalValueSummary *S = - Index.findSummaryInModule(ImpF, ImpM.getIdentifier()); + Index.findSummaryInModule(GUID, ImpM.getIdentifier()); AddUsedThings(S); // If this is an alias, we also care about any types/etc. that the aliasee // may reference. @@ -1395,6 +1400,7 @@ public: llvm::StringRef ModulePath, const std::string &NewModulePath) { std::map<std::string, GVSummaryMapTy> ModuleToSummariesForIndex; + std::error_code EC; gatherImportedSummariesForModule(ModulePath, ModuleToDefinedGVSummaries, ImportList, ModuleToSummariesForIndex); @@ -1403,6 +1409,8 @@ public: sys::fs::OpenFlags::OF_None); if (EC) return errorCodeToError(EC); + + // TODO: Serialize declaration bits to bitcode. writeIndexToFile(CombinedIndex, OS, &ModuleToSummariesForIndex); if (ShouldEmitImportsFiles) { diff --git a/llvm/lib/LTO/LTOBackend.cpp b/llvm/lib/LTO/LTOBackend.cpp index d4b89ed..58434fe 100644 --- a/llvm/lib/LTO/LTOBackend.cpp +++ b/llvm/lib/LTO/LTOBackend.cpp @@ -721,7 +721,14 @@ bool lto::initImportList(const Module &M, if (Summary->modulePath() == M.getModuleIdentifier()) continue; // Add an entry to provoke importing by thinBackend. - ImportList[Summary->modulePath()].insert(GUID); + // Try emplace the entry first. If an entry with the same key already + // exists, set the value to 'std::min(existing-value, new-value)' to make + // sure a definition takes precedence over a declaration. + auto [Iter, Inserted] = ImportList[Summary->modulePath()].try_emplace( + GUID, Summary->importType()); + + if (!Inserted) + Iter->second = std::min(Iter->second, Summary->importType()); } } return true; diff --git a/llvm/lib/Transforms/IPO/FunctionImport.cpp b/llvm/lib/Transforms/IPO/FunctionImport.cpp index 68f9799..a116fd6 100644 --- a/llvm/lib/Transforms/IPO/FunctionImport.cpp +++ b/llvm/lib/Transforms/IPO/FunctionImport.cpp @@ -140,6 +140,17 @@ static cl::opt<bool> ImportAllIndex("import-all-index", cl::desc("Import all external functions in index.")); +/// This is a test-only option. +/// If this option is enabled, the ThinLTO indexing step will import each +/// function declaration as a fallback. In a real build this may increase ram +/// usage of the indexing step unnecessarily. +/// TODO: Implement selective import (based on combined summary analysis) to +/// ensure the imported function has a use case in the postlink pipeline. +static cl::opt<bool> ImportDeclaration( + "import-declaration", cl::init(false), cl::Hidden, + cl::desc("If true, import function declaration as fallback if the function " + "definition is not imported.")); + /// Pass a workload description file - an example of workload would be the /// functions executed to satisfy a RPC request. A workload is defined by a root /// function and the list of functions that are (frequently) needed to satisfy @@ -245,8 +256,12 @@ static auto qualifyCalleeCandidates( } /// Given a list of possible callee implementation for a call site, select one -/// that fits the \p Threshold. If none are found, the Reason will give the last -/// reason for the failure (last, in the order of CalleeSummaryList entries). +/// that fits the \p Threshold for function definition import. If none are +/// found, the Reason will give the last reason for the failure (last, in the +/// order of CalleeSummaryList entries). While looking for a callee definition, +/// sets \p TooLargeOrNoInlineSummary to the last seen too-large or noinline +/// candidate; other modules may want to know the function summary or +/// declaration even if a definition is not needed. /// /// FIXME: select "best" instead of first that fits. But what is "best"? /// - The smallest: more likely to be inlined. @@ -259,24 +274,32 @@ static const GlobalValueSummary * selectCallee(const ModuleSummaryIndex &Index, ArrayRef<std::unique_ptr<GlobalValueSummary>> CalleeSummaryList, unsigned Threshold, StringRef CallerModulePath, + const GlobalValueSummary *&TooLargeOrNoInlineSummary, FunctionImporter::ImportFailureReason &Reason) { + // Records the last summary with reason noinline or too-large. + TooLargeOrNoInlineSummary = nullptr; auto QualifiedCandidates = qualifyCalleeCandidates(Index, CalleeSummaryList, CallerModulePath); for (auto QualifiedValue : QualifiedCandidates) { Reason = QualifiedValue.first; + // Skip a summary if its import is not (proved to be) legal. if (Reason != FunctionImporter::ImportFailureReason::None) continue; auto *Summary = cast<FunctionSummary>(QualifiedValue.second->getBaseObject()); + // Don't bother importing the definition if the chance of inlining it is + // not high enough (except under `--force-import-all`). if ((Summary->instCount() > Threshold) && !Summary->fflags().AlwaysInline && !ForceImportAll) { + TooLargeOrNoInlineSummary = Summary; Reason = FunctionImporter::ImportFailureReason::TooLarge; continue; } - // Don't bother importing if we can't inline it anyway. + // Don't bother importing the definition if we can't inline it anyway. if (Summary->fflags().NoInline && !ForceImportAll) { + TooLargeOrNoInlineSummary = Summary; Reason = FunctionImporter::ImportFailureReason::NoInline; continue; } @@ -358,17 +381,27 @@ class GlobalsImporter final { if (!GVS || !Index.canImportGlobalVar(GVS, /* AnalyzeRefs */ true) || LocalNotInModule(GVS)) continue; - auto ILI = ImportList[RefSummary->modulePath()].insert(VI.getGUID()); + + // If there isn't an entry for GUID, insert <GUID, Definition> pair. + // Otherwise, definition should take precedence over declaration. + auto [Iter, Inserted] = + ImportList[RefSummary->modulePath()].try_emplace( + VI.getGUID(), GlobalValueSummary::Definition); // Only update stat and exports if we haven't already imported this // variable. - if (!ILI.second) + if (!Inserted) { + // Set the value to 'std::min(existing-value, new-value)' to make + // sure a definition takes precedence over a declaration. + Iter->second = std::min(GlobalValueSummary::Definition, Iter->second); break; + } NumImportedGlobalVarsThinLink++; // Any references made by this variable will be marked exported // later, in ComputeCrossModuleImport, after import decisions are // complete, which is more efficient than adding them here. if (ExportLists) - (*ExportLists)[RefSummary->modulePath()].insert(VI); + (*ExportLists)[RefSummary->modulePath()][VI] = + GlobalValueSummary::Definition; // If variable is not writeonly we attempt to recursively analyze // its references in order to import referenced constants. @@ -545,10 +578,11 @@ class WorkloadImportsManager : public ModuleImportsManager { LLVM_DEBUG(dbgs() << "[Workload][Including]" << VI.name() << " from " << ExportingModule << " : " << Function::getGUID(VI.name()) << "\n"); - ImportList[ExportingModule].insert(VI.getGUID()); + ImportList[ExportingModule][VI.getGUID()] = + GlobalValueSummary::Definition; GVI.onImportingSummary(*GVS); if (ExportLists) - (*ExportLists)[ExportingModule].insert(VI); + (*ExportLists)[ExportingModule][VI] = GlobalValueSummary::Definition; } LLVM_DEBUG(dbgs() << "[Workload] Done\n"); } @@ -769,9 +803,28 @@ static void computeImportForFunction( } FunctionImporter::ImportFailureReason Reason{}; - CalleeSummary = selectCallee(Index, VI.getSummaryList(), NewThreshold, - Summary.modulePath(), Reason); + + // `SummaryForDeclImport` is an summary eligible for declaration import. + const GlobalValueSummary *SummaryForDeclImport = nullptr; + CalleeSummary = + selectCallee(Index, VI.getSummaryList(), NewThreshold, + Summary.modulePath(), SummaryForDeclImport, Reason); if (!CalleeSummary) { + // There isn't a callee for definition import but one for declaration + // import. + if (ImportDeclaration && SummaryForDeclImport) { + StringRef DeclSourceModule = SummaryForDeclImport->modulePath(); + + // Since definition takes precedence over declaration for the same VI, + // try emplace <VI, declaration> pair without checking insert result. + // If insert doesn't happen, there must be an existing entry keyed by + // VI. + if (ExportLists) + (*ExportLists)[DeclSourceModule].try_emplace( + VI, GlobalValueSummary::Declaration); + ImportList[DeclSourceModule].try_emplace( + VI.getGUID(), GlobalValueSummary::Declaration); + } // Update with new larger threshold if this was a retry (otherwise // we would have already inserted with NewThreshold above). Also // update failure info if requested. @@ -816,11 +869,15 @@ static void computeImportForFunction( "selectCallee() didn't honor the threshold"); auto ExportModulePath = ResolvedCalleeSummary->modulePath(); - auto ILI = ImportList[ExportModulePath].insert(VI.getGUID()); + + // Try emplace the definition entry, and update stats based on insertion + // status. + auto [Iter, Inserted] = ImportList[ExportModulePath].try_emplace( + VI.getGUID(), GlobalValueSummary::Definition); + // We previously decided to import this GUID definition if it was already // inserted in the set of imports from the exporting module. - bool PreviouslyImported = !ILI.second; - if (!PreviouslyImported) { + if (Inserted || Iter->second == GlobalValueSummary::Declaration) { NumImportedFunctionsThinLink++; if (IsHotCallsite) NumImportedHotFunctionsThinLink++; @@ -828,11 +885,14 @@ static void computeImportForFunction( NumImportedCriticalFunctionsThinLink++; } + if (Iter->second == GlobalValueSummary::Declaration) + Iter->second = GlobalValueSummary::Definition; + // Any calls/references made by this function will be marked exported // later, in ComputeCrossModuleImport, after import decisions are // complete, which is more efficient than adding them here. if (ExportLists) - (*ExportLists)[ExportModulePath].insert(VI); + (*ExportLists)[ExportModulePath][VI] = GlobalValueSummary::Definition; } auto GetAdjustedThreshold = [](unsigned Threshold, bool IsHotCallsite) { @@ -939,12 +999,20 @@ static bool isGlobalVarSummary(const ModuleSummaryIndex &Index, } template <class T> -static unsigned numGlobalVarSummaries(const ModuleSummaryIndex &Index, - T &Cont) { +static unsigned numGlobalVarSummaries(const ModuleSummaryIndex &Index, T &Cont, + unsigned &DefinedGVS, + unsigned &DefinedFS) { unsigned NumGVS = 0; - for (auto &V : Cont) - if (isGlobalVarSummary(Index, V)) + DefinedGVS = 0; + DefinedFS = 0; + for (auto &[GUID, Type] : Cont) { + if (isGlobalVarSummary(Index, GUID)) { + if (Type == GlobalValueSummary::Definition) + ++DefinedGVS; ++NumGVS; + } else if (Type == GlobalValueSummary::Definition) + ++DefinedFS; + } return NumGVS; } #endif @@ -954,13 +1022,12 @@ static bool checkVariableImport( const ModuleSummaryIndex &Index, DenseMap<StringRef, FunctionImporter::ImportMapTy> &ImportLists, DenseMap<StringRef, FunctionImporter::ExportSetTy> &ExportLists) { - DenseSet<GlobalValue::GUID> FlattenedImports; for (auto &ImportPerModule : ImportLists) for (auto &ExportPerModule : ImportPerModule.second) - FlattenedImports.insert(ExportPerModule.second.begin(), - ExportPerModule.second.end()); + for (auto &[GUID, Type] : ExportPerModule.second) + FlattenedImports.insert(GUID); // Checks that all GUIDs of read/writeonly vars we see in export lists // are also in the import lists. Otherwise we my face linker undefs, @@ -979,7 +1046,7 @@ static bool checkVariableImport( }; for (auto &ExportPerModule : ExportLists) - for (auto &VI : ExportPerModule.second) + for (auto &[VI, Unused] : ExportPerModule.second) if (!FlattenedImports.count(VI.getGUID()) && IsReadOrWriteOnlyVarNeedingImporting(ExportPerModule.first, VI)) return false; @@ -1015,7 +1082,11 @@ void llvm::ComputeCrossModuleImport( FunctionImporter::ExportSetTy NewExports; const auto &DefinedGVSummaries = ModuleToDefinedGVSummaries.lookup(ELI.first); - for (auto &EI : ELI.second) { + for (auto &[EI, Type] : ELI.second) { + // If a variable is exported as a declaration, its 'refs' and 'calls' are + // not further exported. + if (Type == GlobalValueSummary::Declaration) + continue; // Find the copy defined in the exporting module so that we can mark the // values it references in that specific definition as exported. // Below we will add all references and called values, without regard to @@ -1034,22 +1105,31 @@ void llvm::ComputeCrossModuleImport( // we convert such variables initializers to "zeroinitializer". // See processGlobalForThinLTO. if (!Index.isWriteOnly(GVS)) - for (const auto &VI : GVS->refs()) - NewExports.insert(VI); + for (const auto &VI : GVS->refs()) { + // Try to emplace the declaration entry. If a definition entry + // already exists for key `VI`, this is a no-op. + NewExports.try_emplace(VI, GlobalValueSummary::Declaration); + } } else { auto *FS = cast<FunctionSummary>(S); - for (const auto &Edge : FS->calls()) - NewExports.insert(Edge.first); - for (const auto &Ref : FS->refs()) - NewExports.insert(Ref); + for (const auto &Edge : FS->calls()) { + // Try to emplace the declaration entry. If a definition entry + // already exists for key `VI`, this is a no-op. + NewExports.try_emplace(Edge.first, GlobalValueSummary::Declaration); + } + for (const auto &Ref : FS->refs()) { + // Try to emplace the declaration entry. If a definition entry + // already exists for key `VI`, this is a no-op. + NewExports.try_emplace(Ref, GlobalValueSummary::Declaration); + } } } - // Prune list computed above to only include values defined in the exporting - // module. We do this after the above insertion since we may hit the same - // ref/call target multiple times in above loop, and it is more efficient to - // avoid a set lookup each time. + // Prune list computed above to only include values defined in the + // exporting module. We do this after the above insertion since we may hit + // the same ref/call target multiple times in above loop, and it is more + // efficient to avoid a set lookup each time. for (auto EI = NewExports.begin(); EI != NewExports.end();) { - if (!DefinedGVSummaries.count(EI->getGUID())) + if (!DefinedGVSummaries.count(EI->first.getGUID())) NewExports.erase(EI++); else ++EI; @@ -1064,18 +1144,29 @@ void llvm::ComputeCrossModuleImport( for (auto &ModuleImports : ImportLists) { auto ModName = ModuleImports.first; auto &Exports = ExportLists[ModName]; - unsigned NumGVS = numGlobalVarSummaries(Index, Exports); - LLVM_DEBUG(dbgs() << "* Module " << ModName << " exports " - << Exports.size() - NumGVS << " functions and " << NumGVS - << " vars. Imports from " << ModuleImports.second.size() - << " modules.\n"); + unsigned DefinedGVS = 0, DefinedFS = 0; + unsigned NumGVS = + numGlobalVarSummaries(Index, Exports, DefinedGVS, DefinedFS); + LLVM_DEBUG(dbgs() << "* Module " << ModName << " exports " << DefinedFS + << " function as definitions, " + << Exports.size() - NumGVS - DefinedFS + << " functions as declarations, " << DefinedGVS + << " var definitions and " << NumGVS - DefinedGVS + << " var declarations. Imports from " + << ModuleImports.second.size() << " modules.\n"); for (auto &Src : ModuleImports.second) { auto SrcModName = Src.first; - unsigned NumGVSPerMod = numGlobalVarSummaries(Index, Src.second); - LLVM_DEBUG(dbgs() << " - " << Src.second.size() - NumGVSPerMod - << " functions imported from " << SrcModName << "\n"); - LLVM_DEBUG(dbgs() << " - " << NumGVSPerMod - << " global vars imported from " << SrcModName << "\n"); + unsigned DefinedGVS = 0, DefinedFS = 0; + unsigned NumGVSPerMod = + numGlobalVarSummaries(Index, Src.second, DefinedGVS, DefinedFS); + LLVM_DEBUG(dbgs() << " - " << DefinedFS << " function definitions and " + << Src.second.size() - NumGVSPerMod - DefinedFS + << " function declarations imported from " << SrcModName + << "\n"); + LLVM_DEBUG(dbgs() << " - " << DefinedGVS << " global vars definition and " + << NumGVSPerMod - DefinedGVS + << " global vars declaration imported from " + << SrcModName << "\n"); } } #endif @@ -1089,11 +1180,17 @@ static void dumpImportListForModule(const ModuleSummaryIndex &Index, << ImportList.size() << " modules.\n"); for (auto &Src : ImportList) { auto SrcModName = Src.first; - unsigned NumGVSPerMod = numGlobalVarSummaries(Index, Src.second); - LLVM_DEBUG(dbgs() << " - " << Src.second.size() - NumGVSPerMod - << " functions imported from " << SrcModName << "\n"); - LLVM_DEBUG(dbgs() << " - " << NumGVSPerMod << " vars imported from " - << SrcModName << "\n"); + unsigned DefinedGVS = 0, DefinedFS = 0; + unsigned NumGVSPerMod = + numGlobalVarSummaries(Index, Src.second, DefinedGVS, DefinedFS); + LLVM_DEBUG(dbgs() << " - " << DefinedFS << " function definitions and " + << Src.second.size() - DefinedFS - NumGVSPerMod + << " function declarations imported from " << SrcModName + << "\n"); + LLVM_DEBUG(dbgs() << " - " << DefinedGVS << " var definitions and " + << NumGVSPerMod - DefinedGVS + << " var declarations imported from " << SrcModName + << "\n"); } } #endif @@ -1149,7 +1246,13 @@ static void ComputeCrossModuleImportForModuleFromIndexForTest( if (Summary->modulePath() == ModulePath) continue; // Add an entry to provoke importing by thinBackend. - ImportList[Summary->modulePath()].insert(GUID); + auto [Iter, Inserted] = ImportList[Summary->modulePath()].try_emplace( + GUID, Summary->importType()); + if (!Inserted) { + // Use 'std::min' to make sure definition (with enum value 0) takes + // precedence over declaration (with enum value 1). + Iter->second = std::min(Iter->second, Summary->importType()); + } } #ifndef NDEBUG dumpImportListForModule(Index, ModulePath, ImportList); @@ -1339,13 +1442,17 @@ void llvm::gatherImportedSummariesForModule( // Include summaries for imports. for (const auto &ILI : ImportList) { auto &SummariesForIndex = ModuleToSummariesForIndex[std::string(ILI.first)]; + const auto &DefinedGVSummaries = ModuleToDefinedGVSummaries.lookup(ILI.first); - for (const auto &GI : ILI.second) { - const auto &DS = DefinedGVSummaries.find(GI); + for (const auto &[GUID, Type] : ILI.second) { + const auto &DS = DefinedGVSummaries.find(GUID); assert(DS != DefinedGVSummaries.end() && "Expected a defined summary for imported global value"); - SummariesForIndex[GI] = DS->second; + if (Type == GlobalValueSummary::Declaration) + continue; + + SummariesForIndex[GUID] = DS->second; } } } @@ -1617,6 +1724,16 @@ Expected<bool> FunctionImporter::importFunctions( for (const auto &FunctionsToImportPerModule : ImportList) { ModuleNameOrderedList.insert(FunctionsToImportPerModule.first); } + + auto getImportType = [&](const FunctionsToImportTy &GUIDToImportType, + GlobalValue::GUID GUID) + -> std::optional<GlobalValueSummary::ImportKind> { + auto Iter = GUIDToImportType.find(GUID); + if (Iter == GUIDToImportType.end()) + return std::nullopt; + return Iter->second; + }; + for (const auto &Name : ModuleNameOrderedList) { // Get the module for the import const auto &FunctionsToImportPerModule = ImportList.find(Name); @@ -1634,17 +1751,27 @@ Expected<bool> FunctionImporter::importFunctions( return std::move(Err); auto &ImportGUIDs = FunctionsToImportPerModule->second; + // Find the globals to import SetVector<GlobalValue *> GlobalsToImport; for (Function &F : *SrcModule) { if (!F.hasName()) continue; auto GUID = F.getGUID(); - auto Import = ImportGUIDs.count(GUID); - LLVM_DEBUG(dbgs() << (Import ? "Is" : "Not") << " importing function " + auto MaybeImportType = getImportType(ImportGUIDs, GUID); + + bool ImportDefinition = + (MaybeImportType && + (*MaybeImportType == GlobalValueSummary::Definition)); + + LLVM_DEBUG(dbgs() << (MaybeImportType ? "Is" : "Not") + << " importing function" + << (ImportDefinition + ? " definition " + : (MaybeImportType ? " declaration " : " ")) << GUID << " " << F.getName() << " from " << SrcModule->getSourceFileName() << "\n"); - if (Import) { + if (ImportDefinition) { if (Error Err = F.materialize()) return std::move(Err); // MemProf should match function's definition and summary, @@ -1670,11 +1797,20 @@ Expected<bool> FunctionImporter::importFunctions( if (!GV.hasName()) continue; auto GUID = GV.getGUID(); - auto Import = ImportGUIDs.count(GUID); - LLVM_DEBUG(dbgs() << (Import ? "Is" : "Not") << " importing global " + auto MaybeImportType = getImportType(ImportGUIDs, GUID); + + bool ImportDefinition = + (MaybeImportType && + (*MaybeImportType == GlobalValueSummary::Definition)); + + LLVM_DEBUG(dbgs() << (MaybeImportType ? "Is" : "Not") + << " importing global" + << (ImportDefinition + ? " definition " + : (MaybeImportType ? " declaration " : " ")) << GUID << " " << GV.getName() << " from " << SrcModule->getSourceFileName() << "\n"); - if (Import) { + if (ImportDefinition) { if (Error Err = GV.materialize()) return std::move(Err); ImportedGVCount += GlobalsToImport.insert(&GV); @@ -1684,11 +1820,20 @@ Expected<bool> FunctionImporter::importFunctions( if (!GA.hasName() || isa<GlobalIFunc>(GA.getAliaseeObject())) continue; auto GUID = GA.getGUID(); - auto Import = ImportGUIDs.count(GUID); - LLVM_DEBUG(dbgs() << (Import ? "Is" : "Not") << " importing alias " + auto MaybeImportType = getImportType(ImportGUIDs, GUID); + + bool ImportDefinition = + (MaybeImportType && + (*MaybeImportType == GlobalValueSummary::Definition)); + + LLVM_DEBUG(dbgs() << (MaybeImportType ? "Is" : "Not") + << " importing alias" + << (ImportDefinition + ? " definition " + : (MaybeImportType ? " declaration " : " ")) << GUID << " " << GA.getName() << " from " << SrcModule->getSourceFileName() << "\n"); - if (Import) { + if (ImportDefinition) { if (Error Err = GA.materialize()) return std::move(Err); // Import alias as a copy of its aliasee. @@ -1754,6 +1899,7 @@ Expected<bool> FunctionImporter::importFunctions( NumImportedFunctions += (ImportedCount - ImportedGVCount); NumImportedGlobalVars += ImportedGVCount; + // TODO: Print counters for definitions and declarations in the debugging log. LLVM_DEBUG(dbgs() << "Imported " << ImportedCount - ImportedGVCount << " functions for Module " << DestModule.getModuleIdentifier() << "\n"); diff --git a/llvm/test/ThinLTO/X86/funcimport-stats.ll b/llvm/test/ThinLTO/X86/funcimport-stats.ll index 913b130..7fcd338 100644 --- a/llvm/test/ThinLTO/X86/funcimport-stats.ll +++ b/llvm/test/ThinLTO/X86/funcimport-stats.ll @@ -9,8 +9,8 @@ ; RUN: cat %t4 | grep 'Is importing aliasee' | count 1 ; RUN: cat %t4 | FileCheck %s -; CHECK: - [[NUM_FUNCS:[0-9]+]] functions imported from -; CHECK-NEXT: - [[NUM_VARS:[0-9]+]] global vars imported from +; CHECK: - [[NUM_FUNCS:[0-9]+]] function definitions and 0 function declarations imported from +; CHECK-NEXT: - [[NUM_VARS:[0-9]+]] global vars definition and 0 global vars declaration imported from ; CHECK: [[NUM_FUNCS]] function-import - Number of functions imported in backend ; CHECK-NEXT: [[NUM_FUNCS]] function-import - Number of functions thin link decided to import diff --git a/llvm/test/ThinLTO/X86/import_callee_declaration.ll b/llvm/test/ThinLTO/X86/import_callee_declaration.ll new file mode 100644 index 0000000..df8a9ce --- /dev/null +++ b/llvm/test/ThinLTO/X86/import_callee_declaration.ll @@ -0,0 +1,180 @@ +; "-debug-only" requires asserts. +; REQUIRES: asserts +; RUN: rm -rf %t && split-file %s %t && cd %t + +; Generate per-module summaries. +; RUN: opt -module-summary main.ll -o main.bc +; RUN: opt -module-summary lib.ll -o lib.bc + +; Generate the combined summary and distributed indices. + +; - For function import, set 'import-instr-limit' to 7 and fall back to import +; function declarations. +; - In main.ll, function 'main' calls 'small_func' and 'large_func'. Both callees +; are defined in lib.ll. 'small_func' has two indirect callees, one is smaller +; and the other one is larger. Both callees of 'small_func' are defined in lib.ll. +; - Given the import limit, in main's combined summary, the import type of 'small_func' +; and 'small_indirect_callee' will be 'definition', and the import type of +; 'large_func' and 'large_indirect_callee' will be 'declaration'. +; +; The test will disassemble combined summaries and check the import type is +; correct. Right now postlink optimizer pipeline doesn't do anything (e.g., +; import the declaration or de-serialize summary attributes yet) so there is +; nothing to test more than the summary content. +; +; RUN: llvm-lto2 run \ +; RUN: -debug-only=function-import \ +; RUN: -import-instr-limit=7 \ +; RUN: -import-declaration \ +; RUN: -thinlto-distributed-indexes \ +; RUN: -r=main.bc,main,px \ +; RUN: -r=main.bc,small_func, \ +; RUN: -r=main.bc,large_func, \ +; RUN: -r=lib.bc,callee,pl \ +; RUN: -r=lib.bc,large_indirect_callee,px \ +; RUN: -r=lib.bc,small_func,px \ +; RUN: -r=lib.bc,large_func,px \ +; RUN: -r=lib.bc,large_indirect_callee_alias,px \ +; RUN: -r=lib.bc,calleeAddrs,px -o summary main.bc lib.bc 2>&1 | FileCheck %s --check-prefix=DUMP +; +; RUN: llvm-lto -thinlto-action=thinlink -import-declaration -import-instr-limit=7 -o combined.index.bc main.bc lib.bc +; RUN: llvm-lto -thinlto-action=distributedindexes -debug-only=function-import -import-declaration -import-instr-limit=7 -thinlto-index combined.index.bc main.bc lib.bc 2>&1 | FileCheck %s --check-prefix=DUMP + +; DUMP: - 2 function definitions and 3 function declarations imported from lib.bc + +; First disassemble per-module summary and find out the GUID for {large_func, large_indirect_callee}. +; +; RUN: llvm-dis lib.bc -o - | FileCheck %s --check-prefix=LIB-DIS +; LIB-DIS: [[LARGEFUNC:\^[0-9]+]] = gv: (name: "large_func", summaries: {{.*}}) ; guid = 2418497564662708935 +; LIB-DIS: [[LARGEINDIRECT:\^[0-9]+]] = gv: (name: "large_indirect_callee", summaries: {{.*}}) ; guid = 14343440786664691134 +; LIB-DIS: [[LARGEINDIRECTALIAS:\^[0-9]+]] = gv: (name: "large_indirect_callee_alias", summaries: {{.*}}, aliasee: [[LARGEINDIRECT]] +; +; Secondly disassemble main's combined summary and test that large callees are +; not imported as declarations yet. +; +; RUN: llvm-dis main.bc.thinlto.bc -o - | FileCheck %s --check-prefix=MAIN-DIS +; +; MAIN-DIS: [[LIBMOD:\^[0-9]+]] = module: (path: "lib.bc", hash: (0, 0, 0, 0, 0)) +; MAIN-DIS-NOT: [[LARGEFUNC:\^[0-9]+]] = gv: (guid: 2418497564662708935, summaries: (function: (module: [[LIBMOD]], flags: ({{.*}} importType: declaration), insts: 8, {{.*}}))) +; MAIN-DIS-NOT: [[LARGEINDIRECT:\^[0-9]+]] = gv: (guid: 14343440786664691134, summaries: (function: (module: [[LIBMOD]], flags: ({{.*}} importType: declaration), insts: 8, {{.*}}))) +; MAIN-DIS-NOT: [[LARGEINDIRECTALIAS:\^[0-9]+]] = gv: (guid: 16730173943625350469, summaries: (alias: (module: [[LIBMOD]], flags: ({{.*}} importType: declaration) + +; Run in-process ThinLTO and tests that +; 1. `callee` remains internalized even if the symbols of its callers +; (large_func and large_indirect_callee) are exported as declarations and visible to main module. +; 2. the debugging logs from `function-import` pass are expected. + +; RUN: llvm-lto2 run \ +; RUN: -debug-only=function-import \ +; RUN: -save-temps \ +; RUN: -import-instr-limit=7 \ +; RUN: -import-declaration \ +; RUN: -r=main.bc,main,px \ +; RUN: -r=main.bc,small_func, \ +; RUN: -r=main.bc,large_func, \ +; RUN: -r=lib.bc,callee,pl \ +; RUN: -r=lib.bc,large_indirect_callee,px \ +; RUN: -r=lib.bc,small_func,px \ +; RUN: -r=lib.bc,large_func,px \ +; RUN: -r=lib.bc,large_indirect_callee_alias,px \ +; RUN: -r=lib.bc,calleeAddrs,px -o in-process main.bc lib.bc 2>&1 | FileCheck %s --check-prefix=IMPORTDUMP + +; Test import status from debugging logs. +; TODO: Serialize declaration bit and test declaration bits are correctly set, +; and extend this test case to test IR once postlink optimizer makes use of +; the import type for declarations. +; IMPORTDUMP-DAG: Not importing function 11825436545918268459 callee from lib.cc +; IMPORTDUMP-DAG: Is importing function declaration 14343440786664691134 large_indirect_callee from lib.cc +; IMPORTDUMP-DAG: Is importing function definition 13568239288960714650 small_indirect_callee from lib.cc +; IMPORTDUMP-DAG: Is importing function definition 6976996067367342685 small_func from lib.cc +; IMPORTDUMP-DAG: Is importing function declaration 2418497564662708935 large_func from lib.cc +; IMPORTDUMP-DAG: Not importing global 7680325410415171624 calleeAddrs from lib.cc +; IMPORTDUMP-DAG: Is importing alias declaration 16730173943625350469 large_indirect_callee_alias from lib.cc + +; RUN: llvm-dis in-process.1.3.import.bc -o - | FileCheck %s --check-prefix=IMPORT + +; RUN: llvm-dis in-process.2.2.internalize.bc -o - | FileCheck %s --check-prefix=INTERNALIZE + +; IMPORT-DAG: define available_externally void @small_func +; IMPORT-DAG: define available_externally hidden void @small_indirect_callee +; IMPORT-DAG: declare void @large_func +; IMPORT-NOT: large_indirect_callee +; IMPORT-NOT: large_indirect_callee_alias + +; INTERNALIZE: define internal void @callee() + +;--- main.ll +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +define i32 @main() { + call void @small_func() + call void @large_func() + ret i32 0 +} + +declare void @small_func() + +; large_func without attributes +declare void @large_func() + +;--- lib.ll +source_filename = "lib.cc" +target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +@calleeAddrs = global [3 x ptr] [ptr @large_indirect_callee, ptr @small_indirect_callee, ptr @large_indirect_callee_alias] + +define void @callee() #1 { + ret void +} + +define void @large_indirect_callee()#2 { + call void @callee() + call void @callee() + call void @callee() + call void @callee() + call void @callee() + call void @callee() + call void @callee() + ret void +} + +define internal void @small_indirect_callee() #0 { + ret void +} + +@large_indirect_callee_alias = alias void(), ptr @large_indirect_callee + +define void @small_func() { +entry: + %0 = load ptr, ptr @calleeAddrs + call void %0(), !prof !0 + %1 = load ptr, ptr getelementptr inbounds ([3 x ptr], ptr @calleeAddrs, i64 0, i64 1) + call void %1(), !prof !1 + %2 = load ptr, ptr getelementptr inbounds ([3 x ptr], ptr @calleeAddrs, i64 0, i64 2) + call void %2(), !prof !2 + ret void +} + +define void @large_func() #0 { +entry: + call void @callee() + call void @callee() + call void @callee() + call void @callee() + call void @callee() + call void @callee() + call void @callee() + ret void +} + +attributes #0 = { nounwind norecurse } + +attributes #1 = { noinline } + +attributes #2 = { norecurse } + +!0 = !{!"VP", i32 0, i64 1, i64 14343440786664691134, i64 1} +!1 = !{!"VP", i32 0, i64 1, i64 13568239288960714650, i64 1} +!2 = !{!"VP", i32 0, i64 1, i64 16730173943625350469, i64 1} diff --git a/llvm/test/Transforms/FunctionImport/funcimport.ll b/llvm/test/Transforms/FunctionImport/funcimport.ll index a0968a6..635750b 100644 --- a/llvm/test/Transforms/FunctionImport/funcimport.ll +++ b/llvm/test/Transforms/FunctionImport/funcimport.ll @@ -166,7 +166,8 @@ declare void @variadic_va_start(...) ; GUID-DAG: GUID {{.*}} is linkoncefunc ; DUMP: Module [[M1:.*]] imports from 1 module -; DUMP-NEXT: 15 functions imported from [[M2:.*]] -; DUMP-NEXT: 4 vars imported from [[M2]] +; DUMP-NEXT: 15 function definitions and 0 function declarations imported from [[M2:.*]] +; DUMP-NEXT: 4 var definitions and 0 var declarations imported from [[M2]] + ; DUMP: Imported 15 functions for Module [[M1]] ; DUMP-NEXT: Imported 4 global variables for Module [[M1]] diff --git a/llvm/tools/llvm-link/llvm-link.cpp b/llvm/tools/llvm-link/llvm-link.cpp index 7794f2d..1b90fce 100644 --- a/llvm/tools/llvm-link/llvm-link.cpp +++ b/llvm/tools/llvm-link/llvm-link.cpp @@ -377,9 +377,13 @@ static bool importFunctions(const char *argv0, Module &DestModule) { if (Verbose) errs() << "Importing " << FunctionName << " from " << FileName << "\n"; + // `-import` specifies the `<filename,function-name>` pairs to import as + // definition, so make the import type definition directly. + // FIXME: A follow-up patch should add test coverage for import declaration + // in `llvm-link` CLI (e.g., by introducing a new command line option). auto &Entry = ImportList[FileNameStringCache.insert(FileName).first->getKey()]; - Entry.insert(F->getGUID()); + Entry[F->getGUID()] = GlobalValueSummary::Definition; } auto CachedModuleLoader = [&](StringRef Identifier) { return ModuleLoaderCache.takeModule(std::string(Identifier)); |