diff options
Diffstat (limited to 'contrib/llvm/lib/LTO/ThinLTOCodeGenerator.cpp')
-rw-r--r-- | contrib/llvm/lib/LTO/ThinLTOCodeGenerator.cpp | 374 |
1 files changed, 297 insertions, 77 deletions
diff --git a/contrib/llvm/lib/LTO/ThinLTOCodeGenerator.cpp b/contrib/llvm/lib/LTO/ThinLTOCodeGenerator.cpp index bfb0980..40537e4 100644 --- a/contrib/llvm/lib/LTO/ThinLTOCodeGenerator.cpp +++ b/contrib/llvm/lib/LTO/ThinLTOCodeGenerator.cpp @@ -21,10 +21,12 @@ #include "llvm/ADT/Statistic.h" #include "llvm/ADT/StringExtras.h" #include "llvm/Analysis/ModuleSummaryAnalysis.h" +#include "llvm/Analysis/ProfileSummaryInfo.h" #include "llvm/Analysis/TargetLibraryInfo.h" #include "llvm/Analysis/TargetTransformInfo.h" +#include "llvm/Bitcode/BitcodeReader.h" +#include "llvm/Bitcode/BitcodeWriter.h" #include "llvm/Bitcode/BitcodeWriterPass.h" -#include "llvm/Bitcode/ReaderWriter.h" #include "llvm/ExecutionEngine/ObjectMemoryBuffer.h" #include "llvm/IR/DiagnosticPrinter.h" #include "llvm/IR/LLVMContext.h" @@ -38,10 +40,13 @@ #include "llvm/Object/ModuleSummaryIndexObjectFile.h" #include "llvm/Support/CachePruning.h" #include "llvm/Support/Debug.h" +#include "llvm/Support/Error.h" #include "llvm/Support/Path.h" #include "llvm/Support/SHA1.h" #include "llvm/Support/TargetRegistry.h" #include "llvm/Support/ThreadPool.h" +#include "llvm/Support/Threading.h" +#include "llvm/Support/ToolOutputFile.h" #include "llvm/Target/TargetMachine.h" #include "llvm/Transforms/IPO.h" #include "llvm/Transforms/IPO/FunctionImport.h" @@ -59,17 +64,34 @@ using namespace llvm; namespace llvm { // Flags -discard-value-names, defined in LTOCodeGenerator.cpp extern cl::opt<bool> LTODiscardValueNames; +extern cl::opt<std::string> LTORemarksFilename; +extern cl::opt<bool> LTOPassRemarksWithHotness; } namespace { -static cl::opt<int> ThreadCount("threads", - cl::init(std::thread::hardware_concurrency())); +static cl::opt<int> + ThreadCount("threads", cl::init(llvm::heavyweight_hardware_concurrency())); -static void diagnosticHandler(const DiagnosticInfo &DI) { - DiagnosticPrinterRawOStream DP(errs()); - DI.print(DP); - errs() << '\n'; +Expected<std::unique_ptr<tool_output_file>> +setupOptimizationRemarks(LLVMContext &Ctx, int Count) { + if (LTOPassRemarksWithHotness) + Ctx.setDiagnosticHotnessRequested(true); + + if (LTORemarksFilename.empty()) + return nullptr; + + std::string FileName = + LTORemarksFilename + ".thin." + llvm::utostr(Count) + ".yaml"; + std::error_code EC; + auto DiagnosticOutputFile = + llvm::make_unique<tool_output_file>(FileName, EC, sys::fs::F_None); + if (EC) + return errorCodeToError(EC); + Ctx.setDiagnosticsOutputFile( + llvm::make_unique<yaml::Output>(DiagnosticOutputFile->os())); + DiagnosticOutputFile->keep(); + return std::move(DiagnosticOutputFile); } // Simple helper to save temporary files for debug. @@ -78,9 +100,9 @@ static void saveTempBitcode(const Module &TheModule, StringRef TempDir, if (TempDir.empty()) return; // User asked to save temps, let dump the bitcode file after import. - auto SaveTempPath = TempDir + llvm::utostr(count) + Suffix; + std::string SaveTempPath = (TempDir + llvm::utostr(count) + Suffix).str(); std::error_code EC; - raw_fd_ostream OS(SaveTempPath.str(), EC, sys::fs::F_None); + raw_fd_ostream OS(SaveTempPath, EC, sys::fs::F_None); if (EC) report_fatal_error(Twine("Failed to open ") + SaveTempPath + " to save optimized bitcode\n"); @@ -128,13 +150,13 @@ static void computePrevailingCopies( } static StringMap<MemoryBufferRef> -generateModuleMap(const std::vector<MemoryBufferRef> &Modules) { +generateModuleMap(const std::vector<ThinLTOBuffer> &Modules) { StringMap<MemoryBufferRef> ModuleMap; for (auto &ModuleBuffer : Modules) { assert(ModuleMap.find(ModuleBuffer.getBufferIdentifier()) == ModuleMap.end() && "Expect unique Buffer Identifier"); - ModuleMap[ModuleBuffer.getBufferIdentifier()] = ModuleBuffer; + ModuleMap[ModuleBuffer.getBufferIdentifier()] = ModuleBuffer.getMemBuffer(); } return ModuleMap; } @@ -144,22 +166,55 @@ static void promoteModule(Module &TheModule, const ModuleSummaryIndex &Index) { report_fatal_error("renameModuleForThinLTO failed"); } +static std::unique_ptr<Module> +loadModuleFromBuffer(const MemoryBufferRef &Buffer, LLVMContext &Context, + bool Lazy, bool IsImporting) { + SMDiagnostic Err; + Expected<std::unique_ptr<Module>> ModuleOrErr = + Lazy + ? getLazyBitcodeModule(Buffer, Context, + /* ShouldLazyLoadMetadata */ true, IsImporting) + : parseBitcodeFile(Buffer, Context); + if (!ModuleOrErr) { + handleAllErrors(ModuleOrErr.takeError(), [&](ErrorInfoBase &EIB) { + SMDiagnostic Err = SMDiagnostic(Buffer.getBufferIdentifier(), + SourceMgr::DK_Error, EIB.message()); + Err.print("ThinLTO", errs()); + }); + report_fatal_error("Can't load module, abort."); + } + return std::move(ModuleOrErr.get()); +} + static void crossImportIntoModule(Module &TheModule, const ModuleSummaryIndex &Index, StringMap<MemoryBufferRef> &ModuleMap, const FunctionImporter::ImportMapTy &ImportList) { - ModuleLoader Loader(TheModule.getContext(), ModuleMap); + auto Loader = [&](StringRef Identifier) { + return loadModuleFromBuffer(ModuleMap[Identifier], TheModule.getContext(), + /*Lazy=*/true, /*IsImporting*/ true); + }; + FunctionImporter Importer(Index, Loader); - Importer.importFunctions(TheModule, ImportList); + Expected<bool> Result = Importer.importFunctions(TheModule, ImportList); + if (!Result) { + handleAllErrors(Result.takeError(), [&](ErrorInfoBase &EIB) { + SMDiagnostic Err = SMDiagnostic(TheModule.getModuleIdentifier(), + SourceMgr::DK_Error, EIB.message()); + Err.print("ThinLTO", errs()); + }); + report_fatal_error("importFunctions failed"); + } } -static void optimizeModule(Module &TheModule, TargetMachine &TM) { +static void optimizeModule(Module &TheModule, TargetMachine &TM, + unsigned OptLevel) { // Populate the PassManager PassManagerBuilder PMB; PMB.LibraryInfo = new TargetLibraryInfoImpl(TM.getTargetTriple()); PMB.Inliner = createFunctionInliningPass(); // FIXME: should get it from the bitcode? - PMB.OptLevel = 3; + PMB.OptLevel = OptLevel; PMB.LoopVectorize = true; PMB.SLPVectorize = true; PMB.VerifyInput = true; @@ -229,25 +284,65 @@ public: const FunctionImporter::ExportSetTy &ExportList, const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR, const GVSummaryMapTy &DefinedFunctions, - const DenseSet<GlobalValue::GUID> &PreservedSymbols) { + const DenseSet<GlobalValue::GUID> &PreservedSymbols, unsigned OptLevel, + const TargetMachineBuilder &TMBuilder) { if (CachePath.empty()) return; + if (!Index.modulePaths().count(ModuleID)) + // The module does not have an entry, it can't have a hash at all + return; + // 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. + // Include the hash for the current module + auto ModHash = Index.getModuleHash(ModuleID); + + if (all_of(ModHash, [](uint32_t V) { return V == 0; })) + // No hash entry, no caching! + return; + SHA1 Hasher; + // Include the parts of the LTO configuration that affect code generation. + auto AddString = [&](StringRef Str) { + Hasher.update(Str); + Hasher.update(ArrayRef<uint8_t>{0}); + }; + auto AddUnsigned = [&](unsigned I) { + uint8_t Data[4]; + Data[0] = I; + Data[1] = I >> 8; + Data[2] = I >> 16; + Data[3] = I >> 24; + Hasher.update(ArrayRef<uint8_t>{Data, 4}); + }; + // 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); + // Hash the optimization level and the target machine settings. + AddString(TMBuilder.MCpu); + // FIXME: Hash more of Options. For now all clients initialize Options from + // command-line flags (which is unsupported in production), but may set + // RelaxELFRelocations. The clang driver can also pass FunctionSections, + // DataSections and DebuggerTuning via command line flags. + AddUnsigned(TMBuilder.Options.RelaxELFRelocations); + AddUnsigned(TMBuilder.Options.FunctionSections); + AddUnsigned(TMBuilder.Options.DataSections); + AddUnsigned((unsigned)TMBuilder.Options.DebuggerTuning); + AddString(TMBuilder.MAttr); + if (TMBuilder.RelocModel) + AddUnsigned(*TMBuilder.RelocModel); + AddUnsigned(TMBuilder.CGOptLevel); + AddUnsigned(OptLevel); + 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 @@ -288,10 +383,9 @@ public: } // Cache the Produced object file - std::unique_ptr<MemoryBuffer> - write(std::unique_ptr<MemoryBuffer> OutputBuffer) { + void write(const MemoryBuffer &OutputBuffer) { if (EntryPath.empty()) - return OutputBuffer; + return; // Write to a temporary to avoid race condition SmallString<128> TempFilename; @@ -304,7 +398,7 @@ public: } { raw_fd_ostream OS(TempFD, /* ShouldClose */ true); - OS << OutputBuffer->getBuffer(); + OS << OutputBuffer.getBuffer(); } // Rename to final destination (hopefully race condition won't matter here) EC = sys::fs::rename(TempFilename, EntryPath); @@ -314,16 +408,8 @@ public: if (EC) report_fatal_error(Twine("Failed to open ") + EntryPath + " to save cached entry\n"); - OS << OutputBuffer->getBuffer(); + OS << OutputBuffer.getBuffer(); } - auto ReloadedBufferOrErr = MemoryBuffer::getFile(EntryPath); - if (auto EC = ReloadedBufferOrErr.getError()) { - // FIXME diagnose - errs() << "error: can't reload cached file '" << EntryPath - << "': " << EC.message() << "\n"; - return OutputBuffer; - } - return std::move(*ReloadedBufferOrErr); } }; @@ -336,7 +422,7 @@ ProcessThinLTOModule(Module &TheModule, ModuleSummaryIndex &Index, const GVSummaryMapTy &DefinedGlobals, const ThinLTOCodeGenerator::CachingOptions &CacheOptions, bool DisableCodeGen, StringRef SaveTempsDir, - unsigned count) { + unsigned OptLevel, unsigned count) { // "Benchmark"-like optimization: single-source case bool SingleModule = (ModuleMap.size() == 1); @@ -368,7 +454,7 @@ ProcessThinLTOModule(Module &TheModule, ModuleSummaryIndex &Index, saveTempBitcode(TheModule, SaveTempsDir, count, ".3.imported.bc"); } - optimizeModule(TheModule, TM); + optimizeModule(TheModule, TM, OptLevel); saveTempBitcode(TheModule, SaveTempsDir, count, ".4.opt.bc"); @@ -377,8 +463,9 @@ ProcessThinLTOModule(Module &TheModule, ModuleSummaryIndex &Index, SmallVector<char, 128> OutputBuffer; { raw_svector_ostream OS(OutputBuffer); - ModuleSummaryIndexBuilder IndexBuilder(&TheModule); - WriteBitcodeToFile(&TheModule, OS, true, &IndexBuilder.getIndex()); + ProfileSummaryInfo PSI(TheModule); + auto Index = buildModuleSummaryIndex(TheModule, nullptr, nullptr); + WriteBitcodeToFile(&TheModule, OS, true, &Index); } return make_unique<ObjectMemoryBuffer>(std::move(OutputBuffer)); } @@ -435,18 +522,27 @@ static void initTMBuilder(TargetMachineBuilder &TMBuilder, } // end anonymous namespace void ThinLTOCodeGenerator::addModule(StringRef Identifier, StringRef Data) { - MemoryBufferRef Buffer(Data, Identifier); + ThinLTOBuffer Buffer(Data, Identifier); if (Modules.empty()) { // First module added, so initialize the triple and some options LLVMContext Context; - Triple TheTriple(getBitcodeTargetTriple(Buffer, Context)); + StringRef TripleStr; + ErrorOr<std::string> TripleOrErr = expectedToErrorOrAndEmitErrors( + Context, getBitcodeTargetTriple(Buffer.getMemBuffer())); + if (TripleOrErr) + TripleStr = *TripleOrErr; + Triple TheTriple(TripleStr); initTMBuilder(TMBuilder, Triple(TheTriple)); } #ifndef NDEBUG else { LLVMContext Context; - assert(TMBuilder.TheTriple.str() == - getBitcodeTargetTriple(Buffer, Context) && + StringRef TripleStr; + ErrorOr<std::string> TripleOrErr = expectedToErrorOrAndEmitErrors( + Context, getBitcodeTargetTriple(Buffer.getMemBuffer())); + if (TripleOrErr) + TripleStr = *TripleOrErr; + assert(TMBuilder.TheTriple.str() == TripleStr && "ThinLTO modules with different triple not supported"); } #endif @@ -477,6 +573,7 @@ std::unique_ptr<TargetMachine> TargetMachineBuilder::create() const { SubtargetFeatures Features(MAttr); Features.getDefaultSubtargetFeatures(TheTriple); std::string FeatureStr = Features.getString(); + return std::unique_ptr<TargetMachine>(TheTarget->createTargetMachine( TheTriple.str(), MCpu, FeatureStr, Options, RelocModel, CodeModel::Default, CGOptLevel)); @@ -490,13 +587,14 @@ std::unique_ptr<ModuleSummaryIndex> ThinLTOCodeGenerator::linkCombinedIndex() { std::unique_ptr<ModuleSummaryIndex> CombinedIndex; uint64_t NextModuleId = 0; for (auto &ModuleBuffer : Modules) { - ErrorOr<std::unique_ptr<object::ModuleSummaryIndexObjectFile>> ObjOrErr = - object::ModuleSummaryIndexObjectFile::create(ModuleBuffer, - diagnosticHandler); - if (std::error_code EC = ObjOrErr.getError()) { + Expected<std::unique_ptr<object::ModuleSummaryIndexObjectFile>> ObjOrErr = + object::ModuleSummaryIndexObjectFile::create( + ModuleBuffer.getMemBuffer()); + if (!ObjOrErr) { // FIXME diagnose - errs() << "error: can't create ModuleSummaryIndexObjectFile for buffer: " - << EC.message() << "\n"; + logAllUnhandledErrors( + ObjOrErr.takeError(), errs(), + "error: can't create ModuleSummaryIndexObjectFile for buffer: "); return nullptr; } auto Index = (*ObjOrErr)->takeIndex(); @@ -517,15 +615,23 @@ void ThinLTOCodeGenerator::promote(Module &TheModule, ModuleSummaryIndex &Index) { auto ModuleCount = Index.modulePaths().size(); auto ModuleIdentifier = TheModule.getModuleIdentifier(); + // Collect for each module the list of function it defines (GUID -> Summary). StringMap<GVSummaryMapTy> ModuleToDefinedGVSummaries; Index.collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries); + // Convert the preserved symbols set from string to GUID + auto GUIDPreservedSymbols = computeGUIDPreservedSymbols( + PreservedSymbols, Triple(TheModule.getTargetTriple())); + + // Compute "dead" symbols, we don't want to import/export these! + auto DeadSymbols = computeDeadSymbols(Index, GUIDPreservedSymbols); + // Generate import/export list StringMap<FunctionImporter::ImportMapTy> ImportLists(ModuleCount); StringMap<FunctionImporter::ExportSetTy> ExportLists(ModuleCount); ComputeCrossModuleImport(Index, ModuleToDefinedGVSummaries, ImportLists, - ExportLists); + ExportLists, &DeadSymbols); // Resolve LinkOnce/Weak symbols. StringMap<std::map<GlobalValue::GUID, GlobalValue::LinkageTypes>> ResolvedODR; @@ -534,6 +640,16 @@ void ThinLTOCodeGenerator::promote(Module &TheModule, thinLTOResolveWeakForLinkerModule( TheModule, ModuleToDefinedGVSummaries[ModuleIdentifier]); + // Promote the exported values in the index, so that they are promoted + // in the module. + auto isExported = [&](StringRef ModuleIdentifier, GlobalValue::GUID GUID) { + const auto &ExportList = ExportLists.find(ModuleIdentifier); + return (ExportList != ExportLists.end() && + ExportList->second.count(GUID)) || + GUIDPreservedSymbols.count(GUID); + }; + thinLTOInternalizeAndPromoteInIndex(Index, isExported); + promoteModule(TheModule, Index); } @@ -549,11 +665,18 @@ void ThinLTOCodeGenerator::crossModuleImport(Module &TheModule, StringMap<GVSummaryMapTy> ModuleToDefinedGVSummaries(ModuleCount); Index.collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries); + // Convert the preserved symbols set from string to GUID + auto GUIDPreservedSymbols = computeGUIDPreservedSymbols( + PreservedSymbols, Triple(TheModule.getTargetTriple())); + + // Compute "dead" symbols, we don't want to import/export these! + auto DeadSymbols = computeDeadSymbols(Index, GUIDPreservedSymbols); + // Generate import/export list StringMap<FunctionImporter::ImportMapTy> ImportLists(ModuleCount); StringMap<FunctionImporter::ExportSetTy> ExportLists(ModuleCount); ComputeCrossModuleImport(Index, ModuleToDefinedGVSummaries, ImportLists, - ExportLists); + ExportLists, &DeadSymbols); auto &ImportList = ImportLists[TheModule.getModuleIdentifier()]; crossImportIntoModule(TheModule, Index, ModuleMap, ImportList); @@ -578,7 +701,7 @@ void ThinLTOCodeGenerator::gatherImportedSummariesForModule( ExportLists); llvm::gatherImportedSummariesForModule(ModulePath, ModuleToDefinedGVSummaries, - ImportLists, + ImportLists[ModulePath], ModuleToSummariesForIndex); } @@ -601,7 +724,7 @@ void ThinLTOCodeGenerator::emitImports(StringRef ModulePath, ExportLists); std::error_code EC; - if ((EC = EmitImportsFiles(ModulePath, OutputName, ImportLists))) + if ((EC = EmitImportsFiles(ModulePath, OutputName, ImportLists[ModulePath]))) report_fatal_error(Twine("Failed to open ") + OutputName + " to save imports lists\n"); } @@ -623,11 +746,14 @@ void ThinLTOCodeGenerator::internalize(Module &TheModule, StringMap<GVSummaryMapTy> ModuleToDefinedGVSummaries(ModuleCount); Index.collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries); + // Compute "dead" symbols, we don't want to import/export these! + auto DeadSymbols = computeDeadSymbols(Index, GUIDPreservedSymbols); + // Generate import/export list StringMap<FunctionImporter::ImportMapTy> ImportLists(ModuleCount); StringMap<FunctionImporter::ExportSetTy> ExportLists(ModuleCount); ComputeCrossModuleImport(Index, ModuleToDefinedGVSummaries, ImportLists, - ExportLists); + ExportLists, &DeadSymbols); auto &ExportList = ExportLists[ModuleIdentifier]; // Be friendly and don't nuke totally the module when the client didn't @@ -654,7 +780,7 @@ void ThinLTOCodeGenerator::optimize(Module &TheModule) { initTMBuilder(TMBuilder, Triple(TheModule.getTargetTriple())); // Optimize now - optimizeModule(TheModule, *TMBuilder.create()); + optimizeModule(TheModule, *TMBuilder.create(), OptLevel); } /** @@ -665,13 +791,61 @@ std::unique_ptr<MemoryBuffer> ThinLTOCodeGenerator::codegen(Module &TheModule) { return codegenModule(TheModule, *TMBuilder.create()); } +/// Write out the generated object file, either from CacheEntryPath or from +/// OutputBuffer, preferring hard-link when possible. +/// Returns the path to the generated file in SavedObjectsDirectoryPath. +static std::string writeGeneratedObject(int count, StringRef CacheEntryPath, + StringRef SavedObjectsDirectoryPath, + const MemoryBuffer &OutputBuffer) { + SmallString<128> OutputPath(SavedObjectsDirectoryPath); + llvm::sys::path::append(OutputPath, Twine(count) + ".thinlto.o"); + OutputPath.c_str(); // Ensure the string is null terminated. + if (sys::fs::exists(OutputPath)) + sys::fs::remove(OutputPath); + + // We don't return a memory buffer to the linker, just a list of files. + if (!CacheEntryPath.empty()) { + // Cache is enabled, hard-link the entry (or copy if hard-link fails). + auto Err = sys::fs::create_hard_link(CacheEntryPath, OutputPath); + if (!Err) + return OutputPath.str(); + // Hard linking failed, try to copy. + Err = sys::fs::copy_file(CacheEntryPath, OutputPath); + if (!Err) + return OutputPath.str(); + // Copy failed (could be because the CacheEntry was removed from the cache + // in the meantime by another process), fall back and try to write down the + // buffer to the output. + errs() << "error: can't link or copy from cached entry '" << CacheEntryPath + << "' to '" << OutputPath << "'\n"; + } + // No cache entry, just write out the buffer. + std::error_code Err; + raw_fd_ostream OS(OutputPath, Err, sys::fs::F_None); + if (Err) + report_fatal_error("Can't open output '" + OutputPath + "'\n"); + OS << OutputBuffer.getBuffer(); + return OutputPath.str(); +} + // Main entry point for the ThinLTO processing void ThinLTOCodeGenerator::run() { + // Prepare the resulting object vector + assert(ProducedBinaries.empty() && "The generator should not be reused"); + if (SavedObjectsDirectoryPath.empty()) + ProducedBinaries.resize(Modules.size()); + else { + sys::fs::create_directories(SavedObjectsDirectoryPath); + bool IsDir; + sys::fs::is_directory(SavedObjectsDirectoryPath, IsDir); + if (!IsDir) + report_fatal_error("Unexistent dir: '" + SavedObjectsDirectoryPath + "'"); + ProducedBinaryFiles.resize(Modules.size()); + } + if (CodeGenOnly) { // Perform only parallel codegen and return. ThreadPool Pool; - assert(ProducedBinaries.empty() && "The generator should not be reused"); - ProducedBinaries.resize(Modules.size()); int count = 0; for (auto &ModuleBuffer : Modules) { Pool.async([&](int count) { @@ -679,10 +853,17 @@ void ThinLTOCodeGenerator::run() { Context.setDiscardValueNames(LTODiscardValueNames); // Parse module now - auto TheModule = loadModuleFromBuffer(ModuleBuffer, Context, false); + auto TheModule = + loadModuleFromBuffer(ModuleBuffer.getMemBuffer(), Context, false, + /*IsImporting*/ false); // CodeGen - ProducedBinaries[count] = codegen(*TheModule); + auto OutputBuffer = codegen(*TheModule); + if (SavedObjectsDirectoryPath.empty()) + ProducedBinaries[count] = std::move(OutputBuffer); + else + ProducedBinaryFiles[count] = writeGeneratedObject( + count, "", SavedObjectsDirectoryPath, *OutputBuffer); }, count++); } @@ -703,9 +884,6 @@ void ThinLTOCodeGenerator::run() { WriteIndexToFile(*Index, OS); } - // Prepare the resulting object vector - assert(ProducedBinaries.empty() && "The generator should not be reused"); - ProducedBinaries.resize(Modules.size()); // Prepare the module map. auto ModuleMap = generateModuleMap(Modules); @@ -715,17 +893,20 @@ void ThinLTOCodeGenerator::run() { StringMap<GVSummaryMapTy> ModuleToDefinedGVSummaries(ModuleCount); Index->collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries); + // Convert the preserved symbols set from string to GUID, this is needed for + // computing the caching hash and the internalization. + auto GUIDPreservedSymbols = + computeGUIDPreservedSymbols(PreservedSymbols, TMBuilder.TheTriple); + + // Compute "dead" symbols, we don't want to import/export these! + auto DeadSymbols = computeDeadSymbols(*Index, GUIDPreservedSymbols); + // Collect the import/export lists for all modules from the call-graph in the // combined index. StringMap<FunctionImporter::ImportMapTy> ImportLists(ModuleCount); StringMap<FunctionImporter::ExportSetTy> ExportLists(ModuleCount); ComputeCrossModuleImport(*Index, ModuleToDefinedGVSummaries, ImportLists, - ExportLists); - - // Convert the preserved symbols set from string to GUID, this is needed for - // computing the caching hash and the internalization. - auto GUIDPreservedSymbols = - computeGUIDPreservedSymbols(PreservedSymbols, TMBuilder.TheTriple); + ExportLists, &DeadSymbols); // We use a std::map here to be able to have a defined ordering when // producing a hash for the cache entry. @@ -764,8 +945,8 @@ void ThinLTOCodeGenerator::run() { std::iota(ModulesOrdering.begin(), ModulesOrdering.end(), 0); std::sort(ModulesOrdering.begin(), ModulesOrdering.end(), [&](int LeftIndex, int RightIndex) { - auto LSize = Modules[LeftIndex].getBufferSize(); - auto RSize = Modules[RightIndex].getBufferSize(); + auto LSize = Modules[LeftIndex].getBuffer().size(); + auto RSize = Modules[RightIndex].getBuffer().size(); return LSize > RSize; }); @@ -784,17 +965,24 @@ void ThinLTOCodeGenerator::run() { ModuleCacheEntry CacheEntry(CacheOptions.Path, *Index, ModuleIdentifier, ImportLists[ModuleIdentifier], ExportList, ResolvedODR[ModuleIdentifier], - DefinedFunctions, GUIDPreservedSymbols); + DefinedFunctions, GUIDPreservedSymbols, + OptLevel, TMBuilder); + auto CacheEntryPath = CacheEntry.getEntryPath(); { auto ErrOrBuffer = CacheEntry.tryLoadingBuffer(); DEBUG(dbgs() << "Cache " << (ErrOrBuffer ? "hit" : "miss") << " '" - << CacheEntry.getEntryPath() << "' for buffer " << count - << " " << ModuleIdentifier << "\n"); + << CacheEntryPath << "' for buffer " << count << " " + << ModuleIdentifier << "\n"); if (ErrOrBuffer) { // Cache Hit! - ProducedBinaries[count] = std::move(ErrOrBuffer.get()); + if (SavedObjectsDirectoryPath.empty()) + ProducedBinaries[count] = std::move(ErrOrBuffer.get()); + else + ProducedBinaryFiles[count] = writeGeneratedObject( + count, CacheEntryPath, SavedObjectsDirectoryPath, + *ErrOrBuffer.get()); return; } } @@ -802,9 +990,17 @@ void ThinLTOCodeGenerator::run() { LLVMContext Context; Context.setDiscardValueNames(LTODiscardValueNames); Context.enableDebugTypeODRUniquing(); + auto DiagFileOrErr = setupOptimizationRemarks(Context, count); + if (!DiagFileOrErr) { + errs() << "Error: " << toString(DiagFileOrErr.takeError()) << "\n"; + report_fatal_error("ThinLTO: Can't get an output file for the " + "remarks"); + } // Parse module now - auto TheModule = loadModuleFromBuffer(ModuleBuffer, Context, false); + auto TheModule = + loadModuleFromBuffer(ModuleBuffer.getMemBuffer(), Context, false, + /*IsImporting*/ false); // Save temps: original file. saveTempBitcode(*TheModule, SaveTempsDir, count, ".0.original.bc"); @@ -815,17 +1011,41 @@ void ThinLTOCodeGenerator::run() { *TheModule, *Index, ModuleMap, *TMBuilder.create(), ImportList, ExportList, GUIDPreservedSymbols, ModuleToDefinedGVSummaries[ModuleIdentifier], CacheOptions, - DisableCodeGen, SaveTempsDir, count); - - OutputBuffer = CacheEntry.write(std::move(OutputBuffer)); - ProducedBinaries[count] = std::move(OutputBuffer); + DisableCodeGen, SaveTempsDir, OptLevel, count); + + // Commit to the cache (if enabled) + CacheEntry.write(*OutputBuffer); + + if (SavedObjectsDirectoryPath.empty()) { + // We need to generated a memory buffer for the linker. + if (!CacheEntryPath.empty()) { + // Cache is enabled, reload from the cache + // We do this to lower memory pressuree: the buffer is on the heap + // and releasing it frees memory that can be used for the next input + // file. The final binary link will read from the VFS cache + // (hopefully!) or from disk if the memory pressure wasn't too high. + auto ReloadedBufferOrErr = CacheEntry.tryLoadingBuffer(); + if (auto EC = ReloadedBufferOrErr.getError()) { + // On error, keeping the preexisting buffer and printing a + // diagnostic is more friendly than just crashing. + errs() << "error: can't reload cached file '" << CacheEntryPath + << "': " << EC.message() << "\n"; + } else { + OutputBuffer = std::move(*ReloadedBufferOrErr); + } + } + ProducedBinaries[count] = std::move(OutputBuffer); + return; + } + ProducedBinaryFiles[count] = writeGeneratedObject( + count, CacheEntryPath, SavedObjectsDirectoryPath, *OutputBuffer); }, IndexCount); } } CachePruning(CacheOptions.Path) - .setPruningInterval(CacheOptions.PruningInterval) - .setEntryExpiration(CacheOptions.Expiration) + .setPruningInterval(std::chrono::seconds(CacheOptions.PruningInterval)) + .setEntryExpiration(std::chrono::seconds(CacheOptions.Expiration)) .setMaxSize(CacheOptions.MaxPercentageOfAvailableSpace) .prune(); |