diff options
Diffstat (limited to 'gnu/llvm/lib/LTO/LTOBackend.cpp')
| -rw-r--r-- | gnu/llvm/lib/LTO/LTOBackend.cpp | 528 |
1 files changed, 0 insertions, 528 deletions
diff --git a/gnu/llvm/lib/LTO/LTOBackend.cpp b/gnu/llvm/lib/LTO/LTOBackend.cpp deleted file mode 100644 index 926c419e34a..00000000000 --- a/gnu/llvm/lib/LTO/LTOBackend.cpp +++ /dev/null @@ -1,528 +0,0 @@ -//===-LTOBackend.cpp - LLVM Link Time Optimizer Backend -------------------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// -// -// This file implements the "backend" phase of LTO, i.e. it performs -// optimization and code generation on a loaded module. It is generally used -// internally by the LTO class but can also be used independently, for example -// to implement a standalone ThinLTO backend. -// -//===----------------------------------------------------------------------===// - -#include "llvm/LTO/LTOBackend.h" -#include "llvm/Analysis/AliasAnalysis.h" -#include "llvm/Analysis/CGSCCPassManager.h" -#include "llvm/Analysis/TargetLibraryInfo.h" -#include "llvm/Analysis/TargetTransformInfo.h" -#include "llvm/Bitcode/BitcodeReader.h" -#include "llvm/Bitcode/BitcodeWriter.h" -#include "llvm/IR/LegacyPassManager.h" -#include "llvm/IR/PassManager.h" -#include "llvm/IR/Verifier.h" -#include "llvm/LTO/LTO.h" -#include "llvm/MC/SubtargetFeature.h" -#include "llvm/Object/ModuleSymbolTable.h" -#include "llvm/Passes/PassBuilder.h" -#include "llvm/Support/Error.h" -#include "llvm/Support/FileSystem.h" -#include "llvm/Support/MemoryBuffer.h" -#include "llvm/Support/Path.h" -#include "llvm/Support/Program.h" -#include "llvm/Support/raw_ostream.h" -#include "llvm/Support/TargetRegistry.h" -#include "llvm/Support/ThreadPool.h" -#include "llvm/Target/TargetMachine.h" -#include "llvm/Transforms/IPO.h" -#include "llvm/Transforms/IPO/PassManagerBuilder.h" -#include "llvm/Transforms/Scalar/LoopPassManager.h" -#include "llvm/Transforms/Utils/FunctionImportUtils.h" -#include "llvm/Transforms/Utils/SplitModule.h" - -using namespace llvm; -using namespace lto; - -LLVM_ATTRIBUTE_NORETURN static void reportOpenError(StringRef Path, Twine Msg) { - errs() << "failed to open " << Path << ": " << Msg << '\n'; - errs().flush(); - exit(1); -} - -Error Config::addSaveTemps(std::string OutputFileName, - bool UseInputModulePath) { - ShouldDiscardValueNames = false; - - std::error_code EC; - ResolutionFile = llvm::make_unique<raw_fd_ostream>( - OutputFileName + "resolution.txt", EC, sys::fs::OpenFlags::F_Text); - if (EC) - return errorCodeToError(EC); - - auto setHook = [&](std::string PathSuffix, ModuleHookFn &Hook) { - // Keep track of the hook provided by the linker, which also needs to run. - ModuleHookFn LinkerHook = Hook; - Hook = [=](unsigned Task, const Module &M) { - // If the linker's hook returned false, we need to pass that result - // through. - if (LinkerHook && !LinkerHook(Task, M)) - return false; - - std::string PathPrefix; - // If this is the combined module (not a ThinLTO backend compile) or the - // user hasn't requested using the input module's path, emit to a file - // named from the provided OutputFileName with the Task ID appended. - if (M.getModuleIdentifier() == "ld-temp.o" || !UseInputModulePath) { - PathPrefix = OutputFileName; - if (Task != (unsigned)-1) - PathPrefix += utostr(Task) + "."; - } else - PathPrefix = M.getModuleIdentifier() + "."; - std::string Path = PathPrefix + PathSuffix + ".bc"; - std::error_code EC; - raw_fd_ostream OS(Path, EC, sys::fs::OpenFlags::F_None); - // Because -save-temps is a debugging feature, we report the error - // directly and exit. - if (EC) - reportOpenError(Path, EC.message()); - WriteBitcodeToFile(M, OS, /*ShouldPreserveUseListOrder=*/false); - return true; - }; - }; - - setHook("0.preopt", PreOptModuleHook); - setHook("1.promote", PostPromoteModuleHook); - setHook("2.internalize", PostInternalizeModuleHook); - setHook("3.import", PostImportModuleHook); - setHook("4.opt", PostOptModuleHook); - setHook("5.precodegen", PreCodeGenModuleHook); - - CombinedIndexHook = [=](const ModuleSummaryIndex &Index) { - std::string Path = OutputFileName + "index.bc"; - std::error_code EC; - raw_fd_ostream OS(Path, EC, sys::fs::OpenFlags::F_None); - // Because -save-temps is a debugging feature, we report the error - // directly and exit. - if (EC) - reportOpenError(Path, EC.message()); - WriteIndexToFile(Index, OS); - - Path = OutputFileName + "index.dot"; - raw_fd_ostream OSDot(Path, EC, sys::fs::OpenFlags::F_None); - if (EC) - reportOpenError(Path, EC.message()); - Index.exportToDot(OSDot); - return true; - }; - - return Error::success(); -} - -namespace { - -std::unique_ptr<TargetMachine> -createTargetMachine(Config &Conf, const Target *TheTarget, Module &M) { - StringRef TheTriple = M.getTargetTriple(); - SubtargetFeatures Features; - Features.getDefaultSubtargetFeatures(Triple(TheTriple)); - for (const std::string &A : Conf.MAttrs) - Features.AddFeature(A); - - Reloc::Model RelocModel; - if (Conf.RelocModel) - RelocModel = *Conf.RelocModel; - else - RelocModel = - M.getPICLevel() == PICLevel::NotPIC ? Reloc::Static : Reloc::PIC_; - - Optional<CodeModel::Model> CodeModel; - if (Conf.CodeModel) - CodeModel = *Conf.CodeModel; - else - CodeModel = M.getCodeModel(); - - return std::unique_ptr<TargetMachine>(TheTarget->createTargetMachine( - TheTriple, Conf.CPU, Features.getString(), Conf.Options, RelocModel, - CodeModel, Conf.CGOptLevel)); -} - -static void runNewPMPasses(Config &Conf, Module &Mod, TargetMachine *TM, - unsigned OptLevel, bool IsThinLTO, - ModuleSummaryIndex *ExportSummary, - const ModuleSummaryIndex *ImportSummary) { - Optional<PGOOptions> PGOOpt; - if (!Conf.SampleProfile.empty()) - PGOOpt = PGOOptions("", "", Conf.SampleProfile, Conf.ProfileRemapping, - false, true); - - PassBuilder PB(TM, PGOOpt); - AAManager AA; - - // Parse a custom AA pipeline if asked to. - if (auto Err = PB.parseAAPipeline(AA, "default")) - report_fatal_error("Error parsing default AA pipeline"); - - LoopAnalysisManager LAM(Conf.DebugPassManager); - FunctionAnalysisManager FAM(Conf.DebugPassManager); - CGSCCAnalysisManager CGAM(Conf.DebugPassManager); - ModuleAnalysisManager MAM(Conf.DebugPassManager); - - // Register the AA manager first so that our version is the one used. - FAM.registerPass([&] { return std::move(AA); }); - - // Register all the basic analyses with the managers. - PB.registerModuleAnalyses(MAM); - PB.registerCGSCCAnalyses(CGAM); - PB.registerFunctionAnalyses(FAM); - PB.registerLoopAnalyses(LAM); - PB.crossRegisterProxies(LAM, FAM, CGAM, MAM); - - ModulePassManager MPM(Conf.DebugPassManager); - // FIXME (davide): verify the input. - - PassBuilder::OptimizationLevel OL; - - switch (OptLevel) { - default: - llvm_unreachable("Invalid optimization level"); - case 0: - OL = PassBuilder::O0; - break; - case 1: - OL = PassBuilder::O1; - break; - case 2: - OL = PassBuilder::O2; - break; - case 3: - OL = PassBuilder::O3; - break; - } - - if (IsThinLTO) - MPM = PB.buildThinLTODefaultPipeline(OL, Conf.DebugPassManager, - ImportSummary); - else - MPM = PB.buildLTODefaultPipeline(OL, Conf.DebugPassManager, ExportSummary); - MPM.run(Mod, MAM); - - // FIXME (davide): verify the output. -} - -static void runNewPMCustomPasses(Module &Mod, TargetMachine *TM, - std::string PipelineDesc, - std::string AAPipelineDesc, - bool DisableVerify) { - PassBuilder PB(TM); - AAManager AA; - - // Parse a custom AA pipeline if asked to. - if (!AAPipelineDesc.empty()) - if (auto Err = PB.parseAAPipeline(AA, AAPipelineDesc)) - report_fatal_error("unable to parse AA pipeline description '" + - AAPipelineDesc + "': " + toString(std::move(Err))); - - LoopAnalysisManager LAM; - FunctionAnalysisManager FAM; - CGSCCAnalysisManager CGAM; - ModuleAnalysisManager MAM; - - // Register the AA manager first so that our version is the one used. - FAM.registerPass([&] { return std::move(AA); }); - - // Register all the basic analyses with the managers. - PB.registerModuleAnalyses(MAM); - PB.registerCGSCCAnalyses(CGAM); - PB.registerFunctionAnalyses(FAM); - PB.registerLoopAnalyses(LAM); - PB.crossRegisterProxies(LAM, FAM, CGAM, MAM); - - ModulePassManager MPM; - - // Always verify the input. - MPM.addPass(VerifierPass()); - - // Now, add all the passes we've been requested to. - if (auto Err = PB.parsePassPipeline(MPM, PipelineDesc)) - report_fatal_error("unable to parse pass pipeline description '" + - PipelineDesc + "': " + toString(std::move(Err))); - - if (!DisableVerify) - MPM.addPass(VerifierPass()); - MPM.run(Mod, MAM); -} - -static void runOldPMPasses(Config &Conf, Module &Mod, TargetMachine *TM, - bool IsThinLTO, ModuleSummaryIndex *ExportSummary, - const ModuleSummaryIndex *ImportSummary) { - legacy::PassManager passes; - passes.add(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis())); - - PassManagerBuilder PMB; - PMB.LibraryInfo = new TargetLibraryInfoImpl(Triple(TM->getTargetTriple())); - PMB.Inliner = createFunctionInliningPass(); - PMB.ExportSummary = ExportSummary; - PMB.ImportSummary = ImportSummary; - // Unconditionally verify input since it is not verified before this - // point and has unknown origin. - PMB.VerifyInput = true; - PMB.VerifyOutput = !Conf.DisableVerify; - PMB.LoopVectorize = true; - PMB.SLPVectorize = true; - PMB.OptLevel = Conf.OptLevel; - PMB.PGOSampleUse = Conf.SampleProfile; - if (IsThinLTO) - PMB.populateThinLTOPassManager(passes); - else - PMB.populateLTOPassManager(passes); - passes.run(Mod); -} - -bool opt(Config &Conf, TargetMachine *TM, unsigned Task, Module &Mod, - bool IsThinLTO, ModuleSummaryIndex *ExportSummary, - const ModuleSummaryIndex *ImportSummary) { - // FIXME: Plumb the combined index into the new pass manager. - if (!Conf.OptPipeline.empty()) - runNewPMCustomPasses(Mod, TM, Conf.OptPipeline, Conf.AAPipeline, - Conf.DisableVerify); - else if (Conf.UseNewPM) - runNewPMPasses(Conf, Mod, TM, Conf.OptLevel, IsThinLTO, ExportSummary, - ImportSummary); - else - runOldPMPasses(Conf, Mod, TM, IsThinLTO, ExportSummary, ImportSummary); - return !Conf.PostOptModuleHook || Conf.PostOptModuleHook(Task, Mod); -} - -void codegen(Config &Conf, TargetMachine *TM, AddStreamFn AddStream, - unsigned Task, Module &Mod) { - if (Conf.PreCodeGenModuleHook && !Conf.PreCodeGenModuleHook(Task, Mod)) - return; - - std::unique_ptr<ToolOutputFile> DwoOut; - SmallString<1024> DwoFile(Conf.DwoPath); - if (!Conf.DwoDir.empty()) { - std::error_code EC; - if (auto EC = llvm::sys::fs::create_directories(Conf.DwoDir)) - report_fatal_error("Failed to create directory " + Conf.DwoDir + ": " + - EC.message()); - - DwoFile = Conf.DwoDir; - sys::path::append(DwoFile, std::to_string(Task) + ".dwo"); - } - - if (!DwoFile.empty()) { - std::error_code EC; - TM->Options.MCOptions.SplitDwarfFile = DwoFile.str().str(); - DwoOut = llvm::make_unique<ToolOutputFile>(DwoFile, EC, sys::fs::F_None); - if (EC) - report_fatal_error("Failed to open " + DwoFile + ": " + EC.message()); - } - - auto Stream = AddStream(Task); - legacy::PassManager CodeGenPasses; - if (TM->addPassesToEmitFile(CodeGenPasses, *Stream->OS, - DwoOut ? &DwoOut->os() : nullptr, - Conf.CGFileType)) - report_fatal_error("Failed to setup codegen"); - CodeGenPasses.run(Mod); - - if (DwoOut) - DwoOut->keep(); -} - -void splitCodeGen(Config &C, TargetMachine *TM, AddStreamFn AddStream, - unsigned ParallelCodeGenParallelismLevel, - std::unique_ptr<Module> Mod) { - ThreadPool CodegenThreadPool(ParallelCodeGenParallelismLevel); - unsigned ThreadCount = 0; - const Target *T = &TM->getTarget(); - - SplitModule( - std::move(Mod), ParallelCodeGenParallelismLevel, - [&](std::unique_ptr<Module> MPart) { - // We want to clone the module in a new context to multi-thread the - // codegen. We do it by serializing partition modules to bitcode - // (while still on the main thread, in order to avoid data races) and - // spinning up new threads which deserialize the partitions into - // separate contexts. - // FIXME: Provide a more direct way to do this in LLVM. - SmallString<0> BC; - raw_svector_ostream BCOS(BC); - WriteBitcodeToFile(*MPart, BCOS); - - // Enqueue the task - CodegenThreadPool.async( - [&](const SmallString<0> &BC, unsigned ThreadId) { - LTOLLVMContext Ctx(C); - Expected<std::unique_ptr<Module>> MOrErr = parseBitcodeFile( - MemoryBufferRef(StringRef(BC.data(), BC.size()), "ld-temp.o"), - Ctx); - if (!MOrErr) - report_fatal_error("Failed to read bitcode"); - std::unique_ptr<Module> MPartInCtx = std::move(MOrErr.get()); - - std::unique_ptr<TargetMachine> TM = - createTargetMachine(C, T, *MPartInCtx); - - codegen(C, TM.get(), AddStream, ThreadId, *MPartInCtx); - }, - // Pass BC using std::move to ensure that it get moved rather than - // copied into the thread's context. - std::move(BC), ThreadCount++); - }, - false); - - // Because the inner lambda (which runs in a worker thread) captures our local - // variables, we need to wait for the worker threads to terminate before we - // can leave the function scope. - CodegenThreadPool.wait(); -} - -Expected<const Target *> initAndLookupTarget(Config &C, Module &Mod) { - if (!C.OverrideTriple.empty()) - Mod.setTargetTriple(C.OverrideTriple); - else if (Mod.getTargetTriple().empty()) - Mod.setTargetTriple(C.DefaultTriple); - - std::string Msg; - const Target *T = TargetRegistry::lookupTarget(Mod.getTargetTriple(), Msg); - if (!T) - return make_error<StringError>(Msg, inconvertibleErrorCode()); - return T; -} - -} - -static Error -finalizeOptimizationRemarks(std::unique_ptr<ToolOutputFile> DiagOutputFile) { - // Make sure we flush the diagnostic remarks file in case the linker doesn't - // call the global destructors before exiting. - if (!DiagOutputFile) - return Error::success(); - DiagOutputFile->keep(); - DiagOutputFile->os().flush(); - return Error::success(); -} - -Error lto::backend(Config &C, AddStreamFn AddStream, - unsigned ParallelCodeGenParallelismLevel, - std::unique_ptr<Module> Mod, - ModuleSummaryIndex &CombinedIndex) { - Expected<const Target *> TOrErr = initAndLookupTarget(C, *Mod); - if (!TOrErr) - return TOrErr.takeError(); - - std::unique_ptr<TargetMachine> TM = createTargetMachine(C, *TOrErr, *Mod); - - // Setup optimization remarks. - auto DiagFileOrErr = lto::setupOptimizationRemarks( - Mod->getContext(), C.RemarksFilename, C.RemarksWithHotness); - if (!DiagFileOrErr) - return DiagFileOrErr.takeError(); - auto DiagnosticOutputFile = std::move(*DiagFileOrErr); - - if (!C.CodeGenOnly) { - if (!opt(C, TM.get(), 0, *Mod, /*IsThinLTO=*/false, - /*ExportSummary=*/&CombinedIndex, /*ImportSummary=*/nullptr)) - return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); - } - - if (ParallelCodeGenParallelismLevel == 1) { - codegen(C, TM.get(), AddStream, 0, *Mod); - } else { - splitCodeGen(C, TM.get(), AddStream, ParallelCodeGenParallelismLevel, - std::move(Mod)); - } - return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); -} - -static void dropDeadSymbols(Module &Mod, const GVSummaryMapTy &DefinedGlobals, - const ModuleSummaryIndex &Index) { - std::vector<GlobalValue*> DeadGVs; - for (auto &GV : Mod.global_values()) - if (GlobalValueSummary *GVS = DefinedGlobals.lookup(GV.getGUID())) - if (!Index.isGlobalValueLive(GVS)) { - DeadGVs.push_back(&GV); - convertToDeclaration(GV); - } - - // Now that all dead bodies have been dropped, delete the actual objects - // themselves when possible. - for (GlobalValue *GV : DeadGVs) { - GV->removeDeadConstantUsers(); - // Might reference something defined in native object (i.e. dropped a - // non-prevailing IR def, but we need to keep the declaration). - if (GV->use_empty()) - GV->eraseFromParent(); - } -} - -Error lto::thinBackend(Config &Conf, unsigned Task, AddStreamFn AddStream, - Module &Mod, const ModuleSummaryIndex &CombinedIndex, - const FunctionImporter::ImportMapTy &ImportList, - const GVSummaryMapTy &DefinedGlobals, - MapVector<StringRef, BitcodeModule> &ModuleMap) { - Expected<const Target *> TOrErr = initAndLookupTarget(Conf, Mod); - if (!TOrErr) - return TOrErr.takeError(); - - std::unique_ptr<TargetMachine> TM = createTargetMachine(Conf, *TOrErr, Mod); - - // Setup optimization remarks. - auto DiagFileOrErr = lto::setupOptimizationRemarks( - Mod.getContext(), Conf.RemarksFilename, Conf.RemarksWithHotness, Task); - if (!DiagFileOrErr) - return DiagFileOrErr.takeError(); - auto DiagnosticOutputFile = std::move(*DiagFileOrErr); - - if (Conf.CodeGenOnly) { - codegen(Conf, TM.get(), AddStream, Task, Mod); - return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); - } - - if (Conf.PreOptModuleHook && !Conf.PreOptModuleHook(Task, Mod)) - return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); - - renameModuleForThinLTO(Mod, CombinedIndex); - - dropDeadSymbols(Mod, DefinedGlobals, CombinedIndex); - - thinLTOResolvePrevailingInModule(Mod, DefinedGlobals); - - if (Conf.PostPromoteModuleHook && !Conf.PostPromoteModuleHook(Task, Mod)) - return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); - - if (!DefinedGlobals.empty()) - thinLTOInternalizeModule(Mod, DefinedGlobals); - - if (Conf.PostInternalizeModuleHook && - !Conf.PostInternalizeModuleHook(Task, Mod)) - return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); - - auto ModuleLoader = [&](StringRef Identifier) { - assert(Mod.getContext().isODRUniquingDebugTypes() && - "ODR Type uniquing should be enabled on the context"); - auto I = ModuleMap.find(Identifier); - assert(I != ModuleMap.end()); - return I->second.getLazyModule(Mod.getContext(), - /*ShouldLazyLoadMetadata=*/true, - /*IsImporting*/ true); - }; - - FunctionImporter Importer(CombinedIndex, ModuleLoader); - if (Error Err = Importer.importFunctions(Mod, ImportList).takeError()) - return Err; - - if (Conf.PostImportModuleHook && !Conf.PostImportModuleHook(Task, Mod)) - return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); - - if (!opt(Conf, TM.get(), Task, Mod, /*IsThinLTO=*/true, - /*ExportSummary=*/nullptr, /*ImportSummary=*/&CombinedIndex)) - return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); - - codegen(Conf, TM.get(), AddStream, Task, Mod); - return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile)); -} |