| //===-LTO.cpp - LLVM Link Time Optimizer ----------------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements functions and classes used to support LTO. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/LTO/LTO.h" |
| #include "llvm/Analysis/TargetLibraryInfo.h" |
| #include "llvm/Analysis/TargetTransformInfo.h" |
| #include "llvm/Bitcode/ReaderWriter.h" |
| #include "llvm/CodeGen/Analysis.h" |
| #include "llvm/IR/AutoUpgrade.h" |
| #include "llvm/IR/DiagnosticPrinter.h" |
| #include "llvm/IR/LegacyPassManager.h" |
| #include "llvm/LTO/LTOBackend.h" |
| #include "llvm/Linker/IRMover.h" |
| #include "llvm/Object/ModuleSummaryIndexObjectFile.h" |
| #include "llvm/Support/ManagedStatic.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/Path.h" |
| #include "llvm/Support/SHA1.h" |
| #include "llvm/Support/SourceMgr.h" |
| #include "llvm/Support/TargetRegistry.h" |
| #include "llvm/Support/ThreadPool.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include "llvm/Target/TargetOptions.h" |
| #include "llvm/Transforms/IPO.h" |
| #include "llvm/Transforms/IPO/PassManagerBuilder.h" |
| #include "llvm/Transforms/Utils/SplitModule.h" |
| |
| #include <set> |
| |
| using namespace llvm; |
| using namespace lto; |
| using namespace object; |
| |
| #define DEBUG_TYPE "lto" |
| |
| // Returns a unique hash for the Module considering the current list of |
| // export/import and other global analysis results. |
| // The hash is produced in \p Key. |
| static void computeCacheKey( |
| SmallString<40> &Key, const ModuleSummaryIndex &Index, StringRef ModuleID, |
| const FunctionImporter::ImportMapTy &ImportList, |
| const FunctionImporter::ExportSetTy &ExportList, |
| const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR, |
| const GVSummaryMapTy &DefinedGlobals) { |
| // Compute the unique hash for this entry. |
| // This is based on the current compiler version, the module itself, the |
| // export list, the hash for every single module in the import list, the |
| // list of ResolvedODR for the module, and the list of preserved symbols. |
| SHA1 Hasher; |
| |
| // Start with the compiler revision |
| Hasher.update(LLVM_VERSION_STRING); |
| #ifdef HAVE_LLVM_REVISION |
| Hasher.update(LLVM_REVISION); |
| #endif |
| |
| // Include the hash for the current module |
| auto ModHash = Index.getModuleHash(ModuleID); |
| Hasher.update(ArrayRef<uint8_t>((uint8_t *)&ModHash[0], sizeof(ModHash))); |
| for (auto F : ExportList) |
| // The export list can impact the internalization, be conservative here |
| Hasher.update(ArrayRef<uint8_t>((uint8_t *)&F, sizeof(F))); |
| |
| // Include the hash for every module we import functions from |
| for (auto &Entry : ImportList) { |
| auto ModHash = Index.getModuleHash(Entry.first()); |
| Hasher.update(ArrayRef<uint8_t>((uint8_t *)&ModHash[0], sizeof(ModHash))); |
| } |
| |
| // Include the hash for the resolved ODR. |
| for (auto &Entry : ResolvedODR) { |
| Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&Entry.first, |
| sizeof(GlobalValue::GUID))); |
| Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&Entry.second, |
| sizeof(GlobalValue::LinkageTypes))); |
| } |
| |
| // Include the hash for the linkage type to reflect internalization and weak |
| // resolution. |
| for (auto &GS : DefinedGlobals) { |
| GlobalValue::LinkageTypes Linkage = GS.second->linkage(); |
| Hasher.update( |
| ArrayRef<uint8_t>((const uint8_t *)&Linkage, sizeof(Linkage))); |
| } |
| |
| Key = toHex(Hasher.result()); |
| } |
| |
| // Simple helper to load a module from bitcode |
| std::unique_ptr<Module> |
| llvm::loadModuleFromBuffer(const MemoryBufferRef &Buffer, LLVMContext &Context, |
| bool Lazy) { |
| SMDiagnostic Err; |
| ErrorOr<std::unique_ptr<Module>> ModuleOrErr(nullptr); |
| if (Lazy) { |
| ModuleOrErr = |
| getLazyBitcodeModule(MemoryBuffer::getMemBuffer(Buffer, false), Context, |
| /* ShouldLazyLoadMetadata */ Lazy); |
| } else { |
| ModuleOrErr = parseBitcodeFile(Buffer, Context); |
| } |
| if (std::error_code EC = ModuleOrErr.getError()) { |
| Err = SMDiagnostic(Buffer.getBufferIdentifier(), SourceMgr::DK_Error, |
| EC.message()); |
| Err.print("ThinLTO", errs()); |
| report_fatal_error("Can't load module, abort."); |
| } |
| return std::move(ModuleOrErr.get()); |
| } |
| |
| static void thinLTOResolveWeakForLinkerGUID( |
| GlobalValueSummaryList &GVSummaryList, GlobalValue::GUID GUID, |
| DenseSet<GlobalValueSummary *> &GlobalInvolvedWithAlias, |
| function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)> |
| isPrevailing, |
| function_ref<void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)> |
| recordNewLinkage) { |
| for (auto &S : GVSummaryList) { |
| if (GlobalInvolvedWithAlias.count(S.get())) |
| continue; |
| GlobalValue::LinkageTypes OriginalLinkage = S->linkage(); |
| if (!GlobalValue::isWeakForLinker(OriginalLinkage)) |
| continue; |
| // We need to emit only one of these. The prevailing module will keep it, |
| // but turned into a weak, while the others will drop it when possible. |
| if (isPrevailing(GUID, S.get())) { |
| if (GlobalValue::isLinkOnceLinkage(OriginalLinkage)) |
| S->setLinkage(GlobalValue::getWeakLinkage( |
| GlobalValue::isLinkOnceODRLinkage(OriginalLinkage))); |
| } |
| // Alias can't be turned into available_externally. |
| else if (!isa<AliasSummary>(S.get()) && |
| (GlobalValue::isLinkOnceODRLinkage(OriginalLinkage) || |
| GlobalValue::isWeakODRLinkage(OriginalLinkage))) |
| S->setLinkage(GlobalValue::AvailableExternallyLinkage); |
| if (S->linkage() != OriginalLinkage) |
| recordNewLinkage(S->modulePath(), GUID, S->linkage()); |
| } |
| } |
| |
| // Resolve Weak and LinkOnce values in the \p Index. |
| // |
| // We'd like to drop these functions if they are no longer referenced in the |
| // current module. However there is a chance that another module is still |
| // referencing them because of the import. We make sure we always emit at least |
| // one copy. |
| void llvm::thinLTOResolveWeakForLinkerInIndex( |
| ModuleSummaryIndex &Index, |
| function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)> |
| isPrevailing, |
| function_ref<void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)> |
| recordNewLinkage) { |
| // We won't optimize the globals that are referenced by an alias for now |
| // Ideally we should turn the alias into a global and duplicate the definition |
| // when needed. |
| DenseSet<GlobalValueSummary *> GlobalInvolvedWithAlias; |
| for (auto &I : Index) |
| for (auto &S : I.second) |
| if (auto AS = dyn_cast<AliasSummary>(S.get())) |
| GlobalInvolvedWithAlias.insert(&AS->getAliasee()); |
| |
| for (auto &I : Index) |
| thinLTOResolveWeakForLinkerGUID(I.second, I.first, GlobalInvolvedWithAlias, |
| isPrevailing, recordNewLinkage); |
| } |
| |
| static void thinLTOInternalizeAndPromoteGUID( |
| GlobalValueSummaryList &GVSummaryList, GlobalValue::GUID GUID, |
| function_ref<bool(StringRef, GlobalValue::GUID)> isExported) { |
| for (auto &S : GVSummaryList) { |
| if (isExported(S->modulePath(), GUID)) { |
| if (GlobalValue::isLocalLinkage(S->linkage())) |
| S->setLinkage(GlobalValue::ExternalLinkage); |
| } else if (!GlobalValue::isLocalLinkage(S->linkage())) |
| S->setLinkage(GlobalValue::InternalLinkage); |
| } |
| } |
| |
| // Update the linkages in the given \p Index to mark exported values |
| // as external and non-exported values as internal. |
| void llvm::thinLTOInternalizeAndPromoteInIndex( |
| ModuleSummaryIndex &Index, |
| function_ref<bool(StringRef, GlobalValue::GUID)> isExported) { |
| for (auto &I : Index) |
| thinLTOInternalizeAndPromoteGUID(I.second, I.first, isExported); |
| } |
| |
| Expected<std::unique_ptr<InputFile>> InputFile::create(MemoryBufferRef Object) { |
| std::unique_ptr<InputFile> File(new InputFile); |
| std::string Msg; |
| auto DiagHandler = [](const DiagnosticInfo &DI, void *MsgP) { |
| auto *Msg = reinterpret_cast<std::string *>(MsgP); |
| raw_string_ostream OS(*Msg); |
| DiagnosticPrinterRawOStream DP(OS); |
| DI.print(DP); |
| }; |
| File->Ctx.setDiagnosticHandler(DiagHandler, static_cast<void *>(&Msg)); |
| |
| ErrorOr<std::unique_ptr<object::IRObjectFile>> IRObj = |
| IRObjectFile::create(Object, File->Ctx); |
| if (!Msg.empty()) |
| return make_error<StringError>(Msg, inconvertibleErrorCode()); |
| if (!IRObj) |
| return errorCodeToError(IRObj.getError()); |
| File->Obj = std::move(*IRObj); |
| |
| File->Ctx.setDiagnosticHandler(nullptr, nullptr); |
| |
| return std::move(File); |
| } |
| |
| LTO::RegularLTOState::RegularLTOState(unsigned ParallelCodeGenParallelismLevel, |
| Config &Conf) |
| : ParallelCodeGenParallelismLevel(ParallelCodeGenParallelismLevel), |
| Ctx(Conf) {} |
| |
| LTO::ThinLTOState::ThinLTOState(ThinBackend Backend) : Backend(Backend) { |
| if (!Backend) |
| this->Backend = createInProcessThinBackend(thread::hardware_concurrency()); |
| } |
| |
| LTO::LTO(Config Conf, ThinBackend Backend, |
| unsigned ParallelCodeGenParallelismLevel) |
| : Conf(std::move(Conf)), |
| RegularLTO(ParallelCodeGenParallelismLevel, this->Conf), |
| ThinLTO(std::move(Backend)) {} |
| |
| // Add the given symbol to the GlobalResolutions map, and resolve its partition. |
| void LTO::addSymbolToGlobalRes(IRObjectFile *Obj, |
| SmallPtrSet<GlobalValue *, 8> &Used, |
| const InputFile::Symbol &Sym, |
| SymbolResolution Res, unsigned Partition) { |
| GlobalValue *GV = Obj->getSymbolGV(Sym.I->getRawDataRefImpl()); |
| |
| auto &GlobalRes = GlobalResolutions[Sym.getName()]; |
| if (GV) { |
| GlobalRes.UnnamedAddr &= GV->hasGlobalUnnamedAddr(); |
| if (Res.Prevailing) |
| GlobalRes.IRName = GV->getName(); |
| } |
| if (Res.VisibleToRegularObj || (GV && Used.count(GV)) || |
| (GlobalRes.Partition != GlobalResolution::Unknown && |
| GlobalRes.Partition != Partition)) |
| GlobalRes.Partition = GlobalResolution::External; |
| else |
| GlobalRes.Partition = Partition; |
| } |
| |
| static void writeToResolutionFile(raw_ostream &OS, InputFile *Input, |
| ArrayRef<SymbolResolution> Res) { |
| StringRef Path = Input->getMemoryBufferRef().getBufferIdentifier(); |
| OS << Path << '\n'; |
| auto ResI = Res.begin(); |
| for (const InputFile::Symbol &Sym : Input->symbols()) { |
| assert(ResI != Res.end()); |
| SymbolResolution Res = *ResI++; |
| |
| OS << "-r=" << Path << ',' << Sym.getName() << ','; |
| if (Res.Prevailing) |
| OS << 'p'; |
| if (Res.FinalDefinitionInLinkageUnit) |
| OS << 'l'; |
| if (Res.VisibleToRegularObj) |
| OS << 'x'; |
| OS << '\n'; |
| } |
| assert(ResI == Res.end()); |
| } |
| |
| Error LTO::add(std::unique_ptr<InputFile> Input, |
| ArrayRef<SymbolResolution> Res) { |
| assert(!CalledGetMaxTasks); |
| |
| if (Conf.ResolutionFile) |
| writeToResolutionFile(*Conf.ResolutionFile, Input.get(), Res); |
| |
| // FIXME: move to backend |
| Module &M = Input->Obj->getModule(); |
| if (!Conf.OverrideTriple.empty()) |
| M.setTargetTriple(Conf.OverrideTriple); |
| else if (M.getTargetTriple().empty()) |
| M.setTargetTriple(Conf.DefaultTriple); |
| |
| MemoryBufferRef MBRef = Input->Obj->getMemoryBufferRef(); |
| bool HasThinLTOSummary = hasGlobalValueSummary(MBRef, Conf.DiagHandler); |
| |
| if (HasThinLTOSummary) |
| return addThinLTO(std::move(Input), Res); |
| else |
| return addRegularLTO(std::move(Input), Res); |
| } |
| |
| // Add a regular LTO object to the link. |
| Error LTO::addRegularLTO(std::unique_ptr<InputFile> Input, |
| ArrayRef<SymbolResolution> Res) { |
| if (!RegularLTO.CombinedModule) { |
| RegularLTO.CombinedModule = |
| llvm::make_unique<Module>("ld-temp.o", RegularLTO.Ctx); |
| RegularLTO.Mover = llvm::make_unique<IRMover>(*RegularLTO.CombinedModule); |
| } |
| ErrorOr<std::unique_ptr<object::IRObjectFile>> ObjOrErr = |
| IRObjectFile::create(Input->Obj->getMemoryBufferRef(), RegularLTO.Ctx); |
| if (!ObjOrErr) |
| return errorCodeToError(ObjOrErr.getError()); |
| std::unique_ptr<object::IRObjectFile> Obj = std::move(*ObjOrErr); |
| |
| Module &M = Obj->getModule(); |
| M.materializeMetadata(); |
| UpgradeDebugInfo(M); |
| |
| SmallPtrSet<GlobalValue *, 8> Used; |
| collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false); |
| |
| std::vector<GlobalValue *> Keep; |
| |
| for (GlobalVariable &GV : M.globals()) |
| if (GV.hasAppendingLinkage()) |
| Keep.push_back(&GV); |
| |
| auto ResI = Res.begin(); |
| for (const InputFile::Symbol &Sym : |
| make_range(InputFile::symbol_iterator(Obj->symbol_begin()), |
| InputFile::symbol_iterator(Obj->symbol_end()))) { |
| assert(ResI != Res.end()); |
| SymbolResolution Res = *ResI++; |
| addSymbolToGlobalRes(Obj.get(), Used, Sym, Res, 0); |
| |
| GlobalValue *GV = Obj->getSymbolGV(Sym.I->getRawDataRefImpl()); |
| if (Sym.getFlags() & object::BasicSymbolRef::SF_Undefined) |
| continue; |
| if (Res.Prevailing && GV) { |
| Keep.push_back(GV); |
| switch (GV->getLinkage()) { |
| default: |
| break; |
| case GlobalValue::LinkOnceAnyLinkage: |
| GV->setLinkage(GlobalValue::WeakAnyLinkage); |
| break; |
| case GlobalValue::LinkOnceODRLinkage: |
| GV->setLinkage(GlobalValue::WeakODRLinkage); |
| break; |
| } |
| } |
| // Common resolution: collect the maximum size/alignment over all commons. |
| // We also record if we see an instance of a common as prevailing, so that |
| // if none is prevailing we can ignore it later. |
| if (Sym.getFlags() & object::BasicSymbolRef::SF_Common) { |
| auto &CommonRes = RegularLTO.Commons[Sym.getIRName()]; |
| CommonRes.Size = std::max(CommonRes.Size, Sym.getCommonSize()); |
| CommonRes.Align = std::max(CommonRes.Align, Sym.getCommonAlignment()); |
| CommonRes.Prevailing |= Res.Prevailing; |
| } |
| |
| // FIXME: use proposed local attribute for FinalDefinitionInLinkageUnit. |
| } |
| assert(ResI == Res.end()); |
| |
| return RegularLTO.Mover->move(Obj->takeModule(), Keep, |
| [](GlobalValue &, IRMover::ValueAdder) {}); |
| } |
| |
| // Add a ThinLTO object to the link. |
| Error LTO::addThinLTO(std::unique_ptr<InputFile> Input, |
| ArrayRef<SymbolResolution> Res) { |
| Module &M = Input->Obj->getModule(); |
| SmallPtrSet<GlobalValue *, 8> Used; |
| collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false); |
| |
| MemoryBufferRef MBRef = Input->Obj->getMemoryBufferRef(); |
| ErrorOr<std::unique_ptr<object::ModuleSummaryIndexObjectFile>> |
| SummaryObjOrErr = |
| object::ModuleSummaryIndexObjectFile::create(MBRef, Conf.DiagHandler); |
| if (!SummaryObjOrErr) |
| return errorCodeToError(SummaryObjOrErr.getError()); |
| ThinLTO.CombinedIndex.mergeFrom((*SummaryObjOrErr)->takeIndex(), |
| ThinLTO.ModuleMap.size()); |
| |
| auto ResI = Res.begin(); |
| for (const InputFile::Symbol &Sym : Input->symbols()) { |
| assert(ResI != Res.end()); |
| SymbolResolution Res = *ResI++; |
| addSymbolToGlobalRes(Input->Obj.get(), Used, Sym, Res, |
| ThinLTO.ModuleMap.size() + 1); |
| |
| GlobalValue *GV = Input->Obj->getSymbolGV(Sym.I->getRawDataRefImpl()); |
| if (Res.Prevailing && GV) |
| ThinLTO.PrevailingModuleForGUID[GV->getGUID()] = |
| MBRef.getBufferIdentifier(); |
| } |
| assert(ResI == Res.end()); |
| |
| ThinLTO.ModuleMap[MBRef.getBufferIdentifier()] = MBRef; |
| return Error(); |
| } |
| |
| unsigned LTO::getMaxTasks() const { |
| CalledGetMaxTasks = true; |
| return RegularLTO.ParallelCodeGenParallelismLevel + ThinLTO.ModuleMap.size(); |
| } |
| |
| Error LTO::run(AddStreamFn AddStream, NativeObjectCache Cache) { |
| // Save the status of having a regularLTO combined module, as |
| // this is needed for generating the ThinLTO Task ID, and |
| // the CombinedModule will be moved at the end of runRegularLTO. |
| bool HasRegularLTO = RegularLTO.CombinedModule != nullptr; |
| // Invoke regular LTO if there was a regular LTO module to start with. |
| if (HasRegularLTO) |
| if (auto E = runRegularLTO(AddStream)) |
| return E; |
| return runThinLTO(AddStream, Cache, HasRegularLTO); |
| } |
| |
| Error LTO::runRegularLTO(AddStreamFn AddStream) { |
| // Make sure commons have the right size/alignment: we kept the largest from |
| // all the prevailing when adding the inputs, and we apply it here. |
| const DataLayout &DL = RegularLTO.CombinedModule->getDataLayout(); |
| for (auto &I : RegularLTO.Commons) { |
| if (!I.second.Prevailing) |
| // Don't do anything if no instance of this common was prevailing. |
| continue; |
| GlobalVariable *OldGV = RegularLTO.CombinedModule->getNamedGlobal(I.first); |
| if (OldGV && DL.getTypeAllocSize(OldGV->getValueType()) == I.second.Size) { |
| // Don't create a new global if the type is already correct, just make |
| // sure the alignment is correct. |
| OldGV->setAlignment(I.second.Align); |
| continue; |
| } |
| ArrayType *Ty = |
| ArrayType::get(Type::getInt8Ty(RegularLTO.Ctx), I.second.Size); |
| auto *GV = new GlobalVariable(*RegularLTO.CombinedModule, Ty, false, |
| GlobalValue::CommonLinkage, |
| ConstantAggregateZero::get(Ty), ""); |
| GV->setAlignment(I.second.Align); |
| if (OldGV) { |
| OldGV->replaceAllUsesWith(ConstantExpr::getBitCast(GV, OldGV->getType())); |
| GV->takeName(OldGV); |
| OldGV->eraseFromParent(); |
| } else { |
| GV->setName(I.first); |
| } |
| } |
| |
| if (Conf.PreOptModuleHook && |
| !Conf.PreOptModuleHook(0, *RegularLTO.CombinedModule)) |
| return Error(); |
| |
| if (!Conf.CodeGenOnly) { |
| for (const auto &R : GlobalResolutions) { |
| if (R.second.IRName.empty()) |
| continue; |
| if (R.second.Partition != 0 && |
| R.second.Partition != GlobalResolution::External) |
| continue; |
| |
| GlobalValue *GV = |
| RegularLTO.CombinedModule->getNamedValue(R.second.IRName); |
| // Ignore symbols defined in other partitions. |
| if (!GV || GV->hasLocalLinkage()) |
| continue; |
| GV->setUnnamedAddr(R.second.UnnamedAddr ? GlobalValue::UnnamedAddr::Global |
| : GlobalValue::UnnamedAddr::None); |
| if (R.second.Partition == 0) |
| GV->setLinkage(GlobalValue::InternalLinkage); |
| } |
| |
| if (Conf.PostInternalizeModuleHook && |
| !Conf.PostInternalizeModuleHook(0, *RegularLTO.CombinedModule)) |
| return Error(); |
| } |
| return backend(Conf, AddStream, RegularLTO.ParallelCodeGenParallelismLevel, |
| std::move(RegularLTO.CombinedModule)); |
| } |
| |
| /// This class defines the interface to the ThinLTO backend. |
| class lto::ThinBackendProc { |
| protected: |
| Config &Conf; |
| ModuleSummaryIndex &CombinedIndex; |
| const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries; |
| |
| public: |
| ThinBackendProc(Config &Conf, ModuleSummaryIndex &CombinedIndex, |
| const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries) |
| : Conf(Conf), CombinedIndex(CombinedIndex), |
| ModuleToDefinedGVSummaries(ModuleToDefinedGVSummaries) {} |
| |
| virtual ~ThinBackendProc() {} |
| virtual Error start( |
| unsigned Task, MemoryBufferRef MBRef, |
| const FunctionImporter::ImportMapTy &ImportList, |
| const FunctionImporter::ExportSetTy &ExportList, |
| const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR, |
| MapVector<StringRef, MemoryBufferRef> &ModuleMap) = 0; |
| virtual Error wait() = 0; |
| }; |
| |
| class InProcessThinBackend : public ThinBackendProc { |
| ThreadPool BackendThreadPool; |
| AddStreamFn AddStream; |
| NativeObjectCache Cache; |
| |
| Optional<Error> Err; |
| std::mutex ErrMu; |
| |
| public: |
| InProcessThinBackend( |
| Config &Conf, ModuleSummaryIndex &CombinedIndex, |
| unsigned ThinLTOParallelismLevel, |
| const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries, |
| AddStreamFn AddStream, NativeObjectCache Cache) |
| : ThinBackendProc(Conf, CombinedIndex, ModuleToDefinedGVSummaries), |
| BackendThreadPool(ThinLTOParallelismLevel), |
| AddStream(std::move(AddStream)), Cache(std::move(Cache)) {} |
| |
| Error runThinLTOBackendThread( |
| AddStreamFn AddStream, NativeObjectCache Cache, unsigned Task, |
| MemoryBufferRef MBRef, ModuleSummaryIndex &CombinedIndex, |
| const FunctionImporter::ImportMapTy &ImportList, |
| const FunctionImporter::ExportSetTy &ExportList, |
| const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR, |
| const GVSummaryMapTy &DefinedGlobals, |
| MapVector<StringRef, MemoryBufferRef> &ModuleMap) { |
| auto RunThinBackend = [&](AddStreamFn AddStream) { |
| LTOLLVMContext BackendContext(Conf); |
| ErrorOr<std::unique_ptr<Module>> MOrErr = |
| parseBitcodeFile(MBRef, BackendContext); |
| assert(MOrErr && "Unable to load module in thread?"); |
| |
| return thinBackend(Conf, Task, AddStream, **MOrErr, CombinedIndex, |
| ImportList, DefinedGlobals, ModuleMap); |
| }; |
| |
| if (!Cache) |
| return RunThinBackend(AddStream); |
| |
| SmallString<40> Key; |
| // The module may be cached, this helps handling it. |
| computeCacheKey(Key, CombinedIndex, MBRef.getBufferIdentifier(), |
| ImportList, ExportList, ResolvedODR, DefinedGlobals); |
| if (AddStreamFn CacheAddStream = Cache(Task, Key)) |
| return RunThinBackend(CacheAddStream); |
| |
| return Error(); |
| } |
| |
| Error start( |
| unsigned Task, MemoryBufferRef MBRef, |
| const FunctionImporter::ImportMapTy &ImportList, |
| const FunctionImporter::ExportSetTy &ExportList, |
| const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR, |
| MapVector<StringRef, MemoryBufferRef> &ModuleMap) override { |
| StringRef ModulePath = MBRef.getBufferIdentifier(); |
| assert(ModuleToDefinedGVSummaries.count(ModulePath)); |
| const GVSummaryMapTy &DefinedGlobals = |
| ModuleToDefinedGVSummaries.find(ModulePath)->second; |
| BackendThreadPool.async( |
| [=](MemoryBufferRef MBRef, ModuleSummaryIndex &CombinedIndex, |
| const FunctionImporter::ImportMapTy &ImportList, |
| const FunctionImporter::ExportSetTy &ExportList, |
| const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> |
| &ResolvedODR, |
| const GVSummaryMapTy &DefinedGlobals, |
| MapVector<StringRef, MemoryBufferRef> &ModuleMap) { |
| Error E = runThinLTOBackendThread( |
| AddStream, Cache, Task, MBRef, CombinedIndex, ImportList, |
| ExportList, ResolvedODR, DefinedGlobals, ModuleMap); |
| if (E) { |
| std::unique_lock<std::mutex> L(ErrMu); |
| if (Err) |
| Err = joinErrors(std::move(*Err), std::move(E)); |
| else |
| Err = std::move(E); |
| } |
| }, |
| MBRef, std::ref(CombinedIndex), std::ref(ImportList), |
| std::ref(ExportList), std::ref(ResolvedODR), std::ref(DefinedGlobals), |
| std::ref(ModuleMap)); |
| return Error(); |
| } |
| |
| Error wait() override { |
| BackendThreadPool.wait(); |
| if (Err) |
| return std::move(*Err); |
| else |
| return Error(); |
| } |
| }; |
| |
| ThinBackend lto::createInProcessThinBackend(unsigned ParallelismLevel) { |
| return [=](Config &Conf, ModuleSummaryIndex &CombinedIndex, |
| const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries, |
| AddStreamFn AddStream, NativeObjectCache Cache) { |
| return llvm::make_unique<InProcessThinBackend>( |
| Conf, CombinedIndex, ParallelismLevel, ModuleToDefinedGVSummaries, |
| AddStream, Cache); |
| }; |
| } |
| |
| // Given the original \p Path to an output file, replace any path |
| // prefix matching \p OldPrefix with \p NewPrefix. Also, create the |
| // resulting directory if it does not yet exist. |
| std::string lto::getThinLTOOutputFile(const std::string &Path, |
| const std::string &OldPrefix, |
| const std::string &NewPrefix) { |
| if (OldPrefix.empty() && NewPrefix.empty()) |
| return Path; |
| SmallString<128> NewPath(Path); |
| llvm::sys::path::replace_path_prefix(NewPath, OldPrefix, NewPrefix); |
| StringRef ParentPath = llvm::sys::path::parent_path(NewPath.str()); |
| if (!ParentPath.empty()) { |
| // Make sure the new directory exists, creating it if necessary. |
| if (std::error_code EC = llvm::sys::fs::create_directories(ParentPath)) |
| llvm::errs() << "warning: could not create directory '" << ParentPath |
| << "': " << EC.message() << '\n'; |
| } |
| return NewPath.str(); |
| } |
| |
| class WriteIndexesThinBackend : public ThinBackendProc { |
| std::string OldPrefix, NewPrefix; |
| bool ShouldEmitImportsFiles; |
| |
| std::string LinkedObjectsFileName; |
| std::unique_ptr<llvm::raw_fd_ostream> LinkedObjectsFile; |
| |
| public: |
| WriteIndexesThinBackend( |
| Config &Conf, ModuleSummaryIndex &CombinedIndex, |
| const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries, |
| std::string OldPrefix, std::string NewPrefix, bool ShouldEmitImportsFiles, |
| std::string LinkedObjectsFileName) |
| : ThinBackendProc(Conf, CombinedIndex, ModuleToDefinedGVSummaries), |
| OldPrefix(OldPrefix), NewPrefix(NewPrefix), |
| ShouldEmitImportsFiles(ShouldEmitImportsFiles), |
| LinkedObjectsFileName(LinkedObjectsFileName) {} |
| |
| Error start( |
| unsigned Task, MemoryBufferRef MBRef, |
| const FunctionImporter::ImportMapTy &ImportList, |
| const FunctionImporter::ExportSetTy &ExportList, |
| const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR, |
| MapVector<StringRef, MemoryBufferRef> &ModuleMap) override { |
| StringRef ModulePath = MBRef.getBufferIdentifier(); |
| std::string NewModulePath = |
| getThinLTOOutputFile(ModulePath, OldPrefix, NewPrefix); |
| |
| std::error_code EC; |
| if (!LinkedObjectsFileName.empty()) { |
| if (!LinkedObjectsFile) { |
| LinkedObjectsFile = llvm::make_unique<raw_fd_ostream>( |
| LinkedObjectsFileName, EC, sys::fs::OpenFlags::F_None); |
| if (EC) |
| return errorCodeToError(EC); |
| } |
| *LinkedObjectsFile << NewModulePath << '\n'; |
| } |
| |
| std::map<std::string, GVSummaryMapTy> ModuleToSummariesForIndex; |
| gatherImportedSummariesForModule(ModulePath, ModuleToDefinedGVSummaries, |
| ImportList, ModuleToSummariesForIndex); |
| |
| raw_fd_ostream OS(NewModulePath + ".thinlto.bc", EC, |
| sys::fs::OpenFlags::F_None); |
| if (EC) |
| return errorCodeToError(EC); |
| WriteIndexToFile(CombinedIndex, OS, &ModuleToSummariesForIndex); |
| |
| if (ShouldEmitImportsFiles) |
| return errorCodeToError( |
| EmitImportsFiles(ModulePath, NewModulePath + ".imports", ImportList)); |
| return Error(); |
| } |
| |
| Error wait() override { return Error(); } |
| }; |
| |
| ThinBackend lto::createWriteIndexesThinBackend(std::string OldPrefix, |
| std::string NewPrefix, |
| bool ShouldEmitImportsFiles, |
| std::string LinkedObjectsFile) { |
| return [=](Config &Conf, ModuleSummaryIndex &CombinedIndex, |
| const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries, |
| AddStreamFn AddStream, NativeObjectCache Cache) { |
| return llvm::make_unique<WriteIndexesThinBackend>( |
| Conf, CombinedIndex, ModuleToDefinedGVSummaries, OldPrefix, NewPrefix, |
| ShouldEmitImportsFiles, LinkedObjectsFile); |
| }; |
| } |
| |
| Error LTO::runThinLTO(AddStreamFn AddStream, NativeObjectCache Cache, |
| bool HasRegularLTO) { |
| if (ThinLTO.ModuleMap.empty()) |
| return Error(); |
| |
| if (Conf.CombinedIndexHook && !Conf.CombinedIndexHook(ThinLTO.CombinedIndex)) |
| return Error(); |
| |
| // Collect for each module the list of function it defines (GUID -> |
| // Summary). |
| StringMap<std::map<GlobalValue::GUID, GlobalValueSummary *>> |
| ModuleToDefinedGVSummaries(ThinLTO.ModuleMap.size()); |
| ThinLTO.CombinedIndex.collectDefinedGVSummariesPerModule( |
| ModuleToDefinedGVSummaries); |
| // Create entries for any modules that didn't have any GV summaries |
| // (either they didn't have any GVs to start with, or we suppressed |
| // generation of the summaries because they e.g. had inline assembly |
| // uses that couldn't be promoted/renamed on export). This is so |
| // InProcessThinBackend::start can still launch a backend thread, which |
| // is passed the map of summaries for the module, without any special |
| // handling for this case. |
| for (auto &Mod : ThinLTO.ModuleMap) |
| if (!ModuleToDefinedGVSummaries.count(Mod.first)) |
| ModuleToDefinedGVSummaries.try_emplace(Mod.first); |
| |
| StringMap<FunctionImporter::ImportMapTy> ImportLists( |
| ThinLTO.ModuleMap.size()); |
| StringMap<FunctionImporter::ExportSetTy> ExportLists( |
| ThinLTO.ModuleMap.size()); |
| ComputeCrossModuleImport(ThinLTO.CombinedIndex, ModuleToDefinedGVSummaries, |
| ImportLists, ExportLists); |
| |
| std::set<GlobalValue::GUID> ExportedGUIDs; |
| for (auto &Res : GlobalResolutions) { |
| if (!Res.second.IRName.empty() && |
| Res.second.Partition == GlobalResolution::External) |
| ExportedGUIDs.insert(GlobalValue::getGUID(Res.second.IRName)); |
| } |
| |
| auto isPrevailing = [&](GlobalValue::GUID GUID, const GlobalValueSummary *S) { |
| return ThinLTO.PrevailingModuleForGUID[GUID] == S->modulePath(); |
| }; |
| auto isExported = [&](StringRef ModuleIdentifier, GlobalValue::GUID GUID) { |
| const auto &ExportList = ExportLists.find(ModuleIdentifier); |
| return (ExportList != ExportLists.end() && |
| ExportList->second.count(GUID)) || |
| ExportedGUIDs.count(GUID); |
| }; |
| thinLTOInternalizeAndPromoteInIndex(ThinLTO.CombinedIndex, isExported); |
| |
| StringMap<std::map<GlobalValue::GUID, GlobalValue::LinkageTypes>> ResolvedODR; |
| auto recordNewLinkage = [&](StringRef ModuleIdentifier, |
| GlobalValue::GUID GUID, |
| GlobalValue::LinkageTypes NewLinkage) { |
| ResolvedODR[ModuleIdentifier][GUID] = NewLinkage; |
| }; |
| |
| thinLTOResolveWeakForLinkerInIndex(ThinLTO.CombinedIndex, isPrevailing, |
| recordNewLinkage); |
| |
| std::unique_ptr<ThinBackendProc> BackendProc = |
| ThinLTO.Backend(Conf, ThinLTO.CombinedIndex, ModuleToDefinedGVSummaries, |
| AddStream, Cache); |
| |
| // Partition numbers for ThinLTO jobs start at 1 (see comments for |
| // GlobalResolution in LTO.h). Task numbers, however, start at |
| // ParallelCodeGenParallelismLevel if an LTO module is present, as tasks 0 |
| // through ParallelCodeGenParallelismLevel-1 are reserved for parallel code |
| // generation partitions. |
| unsigned Task = |
| HasRegularLTO ? RegularLTO.ParallelCodeGenParallelismLevel : 0; |
| unsigned Partition = 1; |
| |
| for (auto &Mod : ThinLTO.ModuleMap) { |
| if (Error E = BackendProc->start(Task, Mod.second, ImportLists[Mod.first], |
| ExportLists[Mod.first], |
| ResolvedODR[Mod.first], ThinLTO.ModuleMap)) |
| return E; |
| |
| ++Task; |
| ++Partition; |
| } |
| |
| return BackendProc->wait(); |
| } |