747 lines
28 KiB
C++
747 lines
28 KiB
C++
//===-LTOBackend.cpp - LLVM Link Time Optimizer Backend -------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements the "backend" phase of LTO, i.e. it performs
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// optimization and code generation on a loaded module. It is generally used
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// internally by the LTO class but can also be used independently, for example
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// to implement a standalone ThinLTO backend.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/LTO/LTOBackend.h"
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#include "llvm/Analysis/AliasAnalysis.h"
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#include "llvm/Analysis/CGSCCPassManager.h"
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#include "llvm/Analysis/ModuleSummaryAnalysis.h"
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#include "llvm/Analysis/TargetLibraryInfo.h"
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#include "llvm/Analysis/TargetTransformInfo.h"
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#include "llvm/Bitcode/BitcodeReader.h"
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#include "llvm/Bitcode/BitcodeWriter.h"
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#include "llvm/IR/LLVMRemarkStreamer.h"
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#include "llvm/IR/LegacyPassManager.h"
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#include "llvm/IR/PassManager.h"
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#include "llvm/IR/Verifier.h"
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#include "llvm/LTO/LTO.h"
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#include "llvm/MC/SubtargetFeature.h"
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#include "llvm/Object/ModuleSymbolTable.h"
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#include "llvm/Passes/PassBuilder.h"
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#include "llvm/Passes/PassPlugin.h"
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#include "llvm/Passes/StandardInstrumentations.h"
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#include "llvm/Support/Error.h"
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#include "llvm/Support/FileSystem.h"
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#include "llvm/Support/MemoryBuffer.h"
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#include "llvm/Support/Path.h"
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#include "llvm/Support/Program.h"
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#include "llvm/Support/SmallVectorMemoryBuffer.h"
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#include "llvm/Support/TargetRegistry.h"
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#include "llvm/Support/ThreadPool.h"
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#include "llvm/Support/raw_ostream.h"
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#include "llvm/Target/TargetMachine.h"
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#include "llvm/Transforms/IPO.h"
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#include "llvm/Transforms/IPO/PassManagerBuilder.h"
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#include "llvm/Transforms/Scalar/LoopPassManager.h"
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#include "llvm/Transforms/Utils/FunctionImportUtils.h"
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#include "llvm/Transforms/Utils/SplitModule.h"
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using namespace llvm;
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using namespace lto;
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#define DEBUG_TYPE "lto-backend"
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enum class LTOBitcodeEmbedding {
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DoNotEmbed = 0,
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EmbedOptimized = 1,
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EmbedPostMergePreOptimized = 2
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};
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static cl::opt<LTOBitcodeEmbedding> EmbedBitcode(
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"lto-embed-bitcode", cl::init(LTOBitcodeEmbedding::DoNotEmbed),
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cl::values(clEnumValN(LTOBitcodeEmbedding::DoNotEmbed, "none",
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"Do not embed"),
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clEnumValN(LTOBitcodeEmbedding::EmbedOptimized, "optimized",
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"Embed after all optimization passes"),
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clEnumValN(LTOBitcodeEmbedding::EmbedPostMergePreOptimized,
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"post-merge-pre-opt",
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"Embed post merge, but before optimizations")),
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cl::desc("Embed LLVM bitcode in object files produced by LTO"));
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static cl::opt<bool> ThinLTOAssumeMerged(
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"thinlto-assume-merged", cl::init(false),
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cl::desc("Assume the input has already undergone ThinLTO function "
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"importing and the other pre-optimization pipeline changes."));
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LLVM_ATTRIBUTE_NORETURN static void reportOpenError(StringRef Path, Twine Msg) {
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errs() << "failed to open " << Path << ": " << Msg << '\n';
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errs().flush();
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exit(1);
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}
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Error Config::addSaveTemps(std::string OutputFileName,
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bool UseInputModulePath) {
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ShouldDiscardValueNames = false;
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std::error_code EC;
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ResolutionFile = std::make_unique<raw_fd_ostream>(
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OutputFileName + "resolution.txt", EC, sys::fs::OpenFlags::OF_Text);
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if (EC) {
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ResolutionFile.reset();
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return errorCodeToError(EC);
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}
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auto setHook = [&](std::string PathSuffix, ModuleHookFn &Hook) {
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// Keep track of the hook provided by the linker, which also needs to run.
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ModuleHookFn LinkerHook = Hook;
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Hook = [=](unsigned Task, const Module &M) {
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// If the linker's hook returned false, we need to pass that result
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// through.
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if (LinkerHook && !LinkerHook(Task, M))
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return false;
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std::string PathPrefix;
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// If this is the combined module (not a ThinLTO backend compile) or the
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// user hasn't requested using the input module's path, emit to a file
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// named from the provided OutputFileName with the Task ID appended.
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if (M.getModuleIdentifier() == "ld-temp.o" || !UseInputModulePath) {
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PathPrefix = OutputFileName;
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if (Task != (unsigned)-1)
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PathPrefix += utostr(Task) + ".";
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} else
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PathPrefix = M.getModuleIdentifier() + ".";
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std::string Path = PathPrefix + PathSuffix + ".bc";
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std::error_code EC;
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raw_fd_ostream OS(Path, EC, sys::fs::OpenFlags::OF_None);
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// Because -save-temps is a debugging feature, we report the error
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// directly and exit.
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if (EC)
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reportOpenError(Path, EC.message());
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WriteBitcodeToFile(M, OS, /*ShouldPreserveUseListOrder=*/false);
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return true;
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};
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};
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setHook("0.preopt", PreOptModuleHook);
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setHook("1.promote", PostPromoteModuleHook);
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setHook("2.internalize", PostInternalizeModuleHook);
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setHook("3.import", PostImportModuleHook);
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setHook("4.opt", PostOptModuleHook);
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setHook("5.precodegen", PreCodeGenModuleHook);
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CombinedIndexHook =
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[=](const ModuleSummaryIndex &Index,
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const DenseSet<GlobalValue::GUID> &GUIDPreservedSymbols) {
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std::string Path = OutputFileName + "index.bc";
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std::error_code EC;
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raw_fd_ostream OS(Path, EC, sys::fs::OpenFlags::OF_None);
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// Because -save-temps is a debugging feature, we report the error
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// directly and exit.
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if (EC)
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reportOpenError(Path, EC.message());
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WriteIndexToFile(Index, OS);
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Path = OutputFileName + "index.dot";
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raw_fd_ostream OSDot(Path, EC, sys::fs::OpenFlags::OF_None);
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if (EC)
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reportOpenError(Path, EC.message());
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Index.exportToDot(OSDot, GUIDPreservedSymbols);
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return true;
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};
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return Error::success();
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}
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#define HANDLE_EXTENSION(Ext) \
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llvm::PassPluginLibraryInfo get##Ext##PluginInfo();
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#include "llvm/Support/Extension.def"
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static void RegisterPassPlugins(ArrayRef<std::string> PassPlugins,
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PassBuilder &PB) {
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#define HANDLE_EXTENSION(Ext) \
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get##Ext##PluginInfo().RegisterPassBuilderCallbacks(PB);
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#include "llvm/Support/Extension.def"
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// Load requested pass plugins and let them register pass builder callbacks
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for (auto &PluginFN : PassPlugins) {
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auto PassPlugin = PassPlugin::Load(PluginFN);
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if (!PassPlugin) {
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errs() << "Failed to load passes from '" << PluginFN
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<< "'. Request ignored.\n";
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continue;
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}
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PassPlugin->registerPassBuilderCallbacks(PB);
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}
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}
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static std::unique_ptr<TargetMachine>
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createTargetMachine(const Config &Conf, const Target *TheTarget, Module &M) {
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StringRef TheTriple = M.getTargetTriple();
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SubtargetFeatures Features;
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Features.getDefaultSubtargetFeatures(Triple(TheTriple));
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for (const std::string &A : Conf.MAttrs)
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Features.AddFeature(A);
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Reloc::Model RelocModel;
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if (Conf.RelocModel)
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RelocModel = *Conf.RelocModel;
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else
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RelocModel =
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M.getPICLevel() == PICLevel::NotPIC ? Reloc::Static : Reloc::PIC_;
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Optional<CodeModel::Model> CodeModel;
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if (Conf.CodeModel)
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CodeModel = *Conf.CodeModel;
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else
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CodeModel = M.getCodeModel();
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std::unique_ptr<TargetMachine> TM(TheTarget->createTargetMachine(
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TheTriple, Conf.CPU, Features.getString(), Conf.Options, RelocModel,
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CodeModel, Conf.CGOptLevel));
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assert(TM && "Failed to create target machine");
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return TM;
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}
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static void runNewPMPasses(const Config &Conf, Module &Mod, TargetMachine *TM,
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unsigned OptLevel, bool IsThinLTO,
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ModuleSummaryIndex *ExportSummary,
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const ModuleSummaryIndex *ImportSummary) {
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Optional<PGOOptions> PGOOpt;
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if (!Conf.SampleProfile.empty())
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PGOOpt = PGOOptions(Conf.SampleProfile, "", Conf.ProfileRemapping,
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PGOOptions::SampleUse, PGOOptions::NoCSAction, true);
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else if (Conf.RunCSIRInstr) {
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PGOOpt = PGOOptions("", Conf.CSIRProfile, Conf.ProfileRemapping,
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PGOOptions::IRUse, PGOOptions::CSIRInstr);
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} else if (!Conf.CSIRProfile.empty()) {
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PGOOpt = PGOOptions(Conf.CSIRProfile, "", Conf.ProfileRemapping,
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PGOOptions::IRUse, PGOOptions::CSIRUse);
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}
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PassInstrumentationCallbacks PIC;
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StandardInstrumentations SI(Conf.DebugPassManager);
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SI.registerCallbacks(PIC);
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PassBuilder PB(Conf.DebugPassManager, TM, Conf.PTO, PGOOpt, &PIC);
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AAManager AA;
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// Parse a custom AA pipeline if asked to.
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if (auto Err = PB.parseAAPipeline(AA, "default"))
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report_fatal_error("Error parsing default AA pipeline");
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RegisterPassPlugins(Conf.PassPlugins, PB);
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LoopAnalysisManager LAM(Conf.DebugPassManager);
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FunctionAnalysisManager FAM(Conf.DebugPassManager);
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CGSCCAnalysisManager CGAM(Conf.DebugPassManager);
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ModuleAnalysisManager MAM(Conf.DebugPassManager);
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std::unique_ptr<TargetLibraryInfoImpl> TLII(
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new TargetLibraryInfoImpl(Triple(TM->getTargetTriple())));
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if (Conf.Freestanding)
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TLII->disableAllFunctions();
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FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
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// Register the AA manager first so that our version is the one used.
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FAM.registerPass([&] { return std::move(AA); });
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// Register all the basic analyses with the managers.
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PB.registerModuleAnalyses(MAM);
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PB.registerCGSCCAnalyses(CGAM);
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PB.registerFunctionAnalyses(FAM);
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PB.registerLoopAnalyses(LAM);
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PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
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ModulePassManager MPM(Conf.DebugPassManager);
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if (!Conf.DisableVerify)
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MPM.addPass(VerifierPass());
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PassBuilder::OptimizationLevel OL;
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switch (OptLevel) {
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default:
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llvm_unreachable("Invalid optimization level");
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case 0:
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OL = PassBuilder::OptimizationLevel::O0;
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break;
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case 1:
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OL = PassBuilder::OptimizationLevel::O1;
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break;
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case 2:
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OL = PassBuilder::OptimizationLevel::O2;
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break;
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case 3:
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OL = PassBuilder::OptimizationLevel::O3;
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break;
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}
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if (IsThinLTO)
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MPM.addPass(PB.buildThinLTODefaultPipeline(OL, ImportSummary));
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else
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MPM.addPass(PB.buildLTODefaultPipeline(OL, ExportSummary));
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if (!Conf.DisableVerify)
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MPM.addPass(VerifierPass());
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MPM.run(Mod, MAM);
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}
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static void runNewPMCustomPasses(const Config &Conf, Module &Mod,
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TargetMachine *TM, std::string PipelineDesc,
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std::string AAPipelineDesc,
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bool DisableVerify) {
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PassBuilder PB(Conf.DebugPassManager, TM);
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AAManager AA;
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// Parse a custom AA pipeline if asked to.
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if (!AAPipelineDesc.empty())
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if (auto Err = PB.parseAAPipeline(AA, AAPipelineDesc))
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report_fatal_error("unable to parse AA pipeline description '" +
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AAPipelineDesc + "': " + toString(std::move(Err)));
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RegisterPassPlugins(Conf.PassPlugins, PB);
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LoopAnalysisManager LAM;
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FunctionAnalysisManager FAM;
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CGSCCAnalysisManager CGAM;
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ModuleAnalysisManager MAM;
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std::unique_ptr<TargetLibraryInfoImpl> TLII(
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new TargetLibraryInfoImpl(Triple(TM->getTargetTriple())));
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if (Conf.Freestanding)
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TLII->disableAllFunctions();
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FAM.registerPass([&] { return TargetLibraryAnalysis(*TLII); });
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// Register the AA manager first so that our version is the one used.
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FAM.registerPass([&] { return std::move(AA); });
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// Register all the basic analyses with the managers.
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PB.registerModuleAnalyses(MAM);
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PB.registerCGSCCAnalyses(CGAM);
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PB.registerFunctionAnalyses(FAM);
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PB.registerLoopAnalyses(LAM);
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PB.crossRegisterProxies(LAM, FAM, CGAM, MAM);
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ModulePassManager MPM;
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// Always verify the input.
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MPM.addPass(VerifierPass());
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// Now, add all the passes we've been requested to.
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if (auto Err = PB.parsePassPipeline(MPM, PipelineDesc))
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report_fatal_error("unable to parse pass pipeline description '" +
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PipelineDesc + "': " + toString(std::move(Err)));
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if (!DisableVerify)
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MPM.addPass(VerifierPass());
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MPM.run(Mod, MAM);
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}
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static void runOldPMPasses(const Config &Conf, Module &Mod, TargetMachine *TM,
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bool IsThinLTO, ModuleSummaryIndex *ExportSummary,
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const ModuleSummaryIndex *ImportSummary) {
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legacy::PassManager passes;
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passes.add(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis()));
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PassManagerBuilder PMB;
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PMB.LibraryInfo = new TargetLibraryInfoImpl(Triple(TM->getTargetTriple()));
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if (Conf.Freestanding)
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PMB.LibraryInfo->disableAllFunctions();
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PMB.Inliner = createFunctionInliningPass();
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PMB.ExportSummary = ExportSummary;
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PMB.ImportSummary = ImportSummary;
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// Unconditionally verify input since it is not verified before this
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// point and has unknown origin.
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PMB.VerifyInput = true;
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PMB.VerifyOutput = !Conf.DisableVerify;
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PMB.LoopVectorize = true;
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PMB.SLPVectorize = true;
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PMB.OptLevel = Conf.OptLevel;
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PMB.PGOSampleUse = Conf.SampleProfile;
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PMB.EnablePGOCSInstrGen = Conf.RunCSIRInstr;
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if (!Conf.RunCSIRInstr && !Conf.CSIRProfile.empty()) {
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PMB.EnablePGOCSInstrUse = true;
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PMB.PGOInstrUse = Conf.CSIRProfile;
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}
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if (IsThinLTO)
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PMB.populateThinLTOPassManager(passes);
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else
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PMB.populateLTOPassManager(passes);
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passes.run(Mod);
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}
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bool lto::opt(const Config &Conf, TargetMachine *TM, unsigned Task, Module &Mod,
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bool IsThinLTO, ModuleSummaryIndex *ExportSummary,
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const ModuleSummaryIndex *ImportSummary,
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const std::vector<uint8_t> &CmdArgs) {
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if (EmbedBitcode == LTOBitcodeEmbedding::EmbedPostMergePreOptimized) {
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// FIXME: the motivation for capturing post-merge bitcode and command line
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// is replicating the compilation environment from bitcode, without needing
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// to understand the dependencies (the functions to be imported). This
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// assumes a clang - based invocation, case in which we have the command
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// line.
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// It's not very clear how the above motivation would map in the
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// linker-based case, so we currently don't plumb the command line args in
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// that case.
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if (CmdArgs.empty())
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LLVM_DEBUG(
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dbgs() << "Post-(Thin)LTO merge bitcode embedding was requested, but "
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"command line arguments are not available");
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llvm::EmbedBitcodeInModule(Mod, llvm::MemoryBufferRef(),
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/*EmbedBitcode*/ true, /*EmbedCmdline*/ true,
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/*Cmdline*/ CmdArgs);
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}
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// FIXME: Plumb the combined index into the new pass manager.
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if (!Conf.OptPipeline.empty())
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runNewPMCustomPasses(Conf, Mod, TM, Conf.OptPipeline, Conf.AAPipeline,
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Conf.DisableVerify);
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else if (Conf.UseNewPM)
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runNewPMPasses(Conf, Mod, TM, Conf.OptLevel, IsThinLTO, ExportSummary,
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ImportSummary);
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else
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runOldPMPasses(Conf, Mod, TM, IsThinLTO, ExportSummary, ImportSummary);
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return !Conf.PostOptModuleHook || Conf.PostOptModuleHook(Task, Mod);
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}
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static void codegen(const Config &Conf, TargetMachine *TM,
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AddStreamFn AddStream, unsigned Task, Module &Mod,
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const ModuleSummaryIndex &CombinedIndex) {
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if (Conf.PreCodeGenModuleHook && !Conf.PreCodeGenModuleHook(Task, Mod))
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return;
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if (EmbedBitcode == LTOBitcodeEmbedding::EmbedOptimized)
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llvm::EmbedBitcodeInModule(Mod, llvm::MemoryBufferRef(),
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/*EmbedBitcode*/ true,
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/*EmbedCmdline*/ false,
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/*CmdArgs*/ std::vector<uint8_t>());
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std::unique_ptr<ToolOutputFile> DwoOut;
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SmallString<1024> DwoFile(Conf.SplitDwarfOutput);
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if (!Conf.DwoDir.empty()) {
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std::error_code EC;
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if (auto EC = llvm::sys::fs::create_directories(Conf.DwoDir))
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report_fatal_error("Failed to create directory " + Conf.DwoDir + ": " +
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EC.message());
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DwoFile = Conf.DwoDir;
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sys::path::append(DwoFile, std::to_string(Task) + ".dwo");
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TM->Options.MCOptions.SplitDwarfFile = std::string(DwoFile);
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} else
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TM->Options.MCOptions.SplitDwarfFile = Conf.SplitDwarfFile;
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if (!DwoFile.empty()) {
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std::error_code EC;
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DwoOut = std::make_unique<ToolOutputFile>(DwoFile, EC, sys::fs::OF_None);
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if (EC)
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report_fatal_error("Failed to open " + DwoFile + ": " + EC.message());
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}
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auto Stream = AddStream(Task);
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legacy::PassManager CodeGenPasses;
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CodeGenPasses.add(
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createImmutableModuleSummaryIndexWrapperPass(&CombinedIndex));
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if (Conf.PreCodeGenPassesHook)
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Conf.PreCodeGenPassesHook(CodeGenPasses);
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if (TM->addPassesToEmitFile(CodeGenPasses, *Stream->OS,
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DwoOut ? &DwoOut->os() : nullptr,
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Conf.CGFileType))
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report_fatal_error("Failed to setup codegen");
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CodeGenPasses.run(Mod);
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if (DwoOut)
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DwoOut->keep();
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}
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static void splitCodeGen(const Config &C, TargetMachine *TM,
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AddStreamFn AddStream,
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unsigned ParallelCodeGenParallelismLevel,
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std::unique_ptr<Module> Mod,
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const ModuleSummaryIndex &CombinedIndex) {
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ThreadPool CodegenThreadPool(
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heavyweight_hardware_concurrency(ParallelCodeGenParallelismLevel));
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unsigned ThreadCount = 0;
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const Target *T = &TM->getTarget();
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|
|
|
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,
|
|
CombinedIndex);
|
|
},
|
|
// 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();
|
|
}
|
|
|
|
static Expected<const Target *> initAndLookupTarget(const 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;
|
|
}
|
|
|
|
Error lto::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(const 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);
|
|
|
|
if (!C.CodeGenOnly) {
|
|
if (!opt(C, TM.get(), 0, *Mod, /*IsThinLTO=*/false,
|
|
/*ExportSummary=*/&CombinedIndex, /*ImportSummary=*/nullptr,
|
|
/*CmdArgs*/ std::vector<uint8_t>()))
|
|
return Error::success();
|
|
}
|
|
|
|
if (ParallelCodeGenParallelismLevel == 1) {
|
|
codegen(C, TM.get(), AddStream, 0, *Mod, CombinedIndex);
|
|
} else {
|
|
splitCodeGen(C, TM.get(), AddStream, ParallelCodeGenParallelismLevel,
|
|
std::move(Mod), CombinedIndex);
|
|
}
|
|
return Error::success();
|
|
}
|
|
|
|
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(const Config &Conf, unsigned Task, AddStreamFn AddStream,
|
|
Module &Mod, const ModuleSummaryIndex &CombinedIndex,
|
|
const FunctionImporter::ImportMapTy &ImportList,
|
|
const GVSummaryMapTy &DefinedGlobals,
|
|
MapVector<StringRef, BitcodeModule> &ModuleMap,
|
|
const std::vector<uint8_t> &CmdArgs) {
|
|
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::setupLLVMOptimizationRemarks(
|
|
Mod.getContext(), Conf.RemarksFilename, Conf.RemarksPasses,
|
|
Conf.RemarksFormat, Conf.RemarksWithHotness, Conf.RemarksHotnessThreshold,
|
|
Task);
|
|
if (!DiagFileOrErr)
|
|
return DiagFileOrErr.takeError();
|
|
auto DiagnosticOutputFile = std::move(*DiagFileOrErr);
|
|
|
|
// Set the partial sample profile ratio in the profile summary module flag of
|
|
// the module, if applicable.
|
|
Mod.setPartialSampleProfileRatio(CombinedIndex);
|
|
|
|
if (Conf.CodeGenOnly) {
|
|
codegen(Conf, TM.get(), AddStream, Task, Mod, CombinedIndex);
|
|
return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile));
|
|
}
|
|
|
|
if (Conf.PreOptModuleHook && !Conf.PreOptModuleHook(Task, Mod))
|
|
return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile));
|
|
|
|
auto OptimizeAndCodegen =
|
|
[&](Module &Mod, TargetMachine *TM,
|
|
std::unique_ptr<ToolOutputFile> DiagnosticOutputFile) {
|
|
if (!opt(Conf, TM, Task, Mod, /*IsThinLTO=*/true,
|
|
/*ExportSummary=*/nullptr, /*ImportSummary=*/&CombinedIndex,
|
|
CmdArgs))
|
|
return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile));
|
|
|
|
codegen(Conf, TM, AddStream, Task, Mod, CombinedIndex);
|
|
return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile));
|
|
};
|
|
|
|
if (ThinLTOAssumeMerged)
|
|
return OptimizeAndCodegen(Mod, TM.get(), std::move(DiagnosticOutputFile));
|
|
|
|
// When linking an ELF shared object, dso_local should be dropped. We
|
|
// conservatively do this for -fpic.
|
|
bool ClearDSOLocalOnDeclarations =
|
|
TM->getTargetTriple().isOSBinFormatELF() &&
|
|
TM->getRelocationModel() != Reloc::Static &&
|
|
Mod.getPIELevel() == PIELevel::Default;
|
|
renameModuleForThinLTO(Mod, CombinedIndex, ClearDSOLocalOnDeclarations);
|
|
|
|
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,
|
|
ClearDSOLocalOnDeclarations);
|
|
if (Error Err = Importer.importFunctions(Mod, ImportList).takeError())
|
|
return Err;
|
|
|
|
if (Conf.PostImportModuleHook && !Conf.PostImportModuleHook(Task, Mod))
|
|
return finalizeOptimizationRemarks(std::move(DiagnosticOutputFile));
|
|
|
|
return OptimizeAndCodegen(Mod, TM.get(), std::move(DiagnosticOutputFile));
|
|
}
|
|
|
|
BitcodeModule *lto::findThinLTOModule(MutableArrayRef<BitcodeModule> BMs) {
|
|
if (ThinLTOAssumeMerged && BMs.size() == 1)
|
|
return BMs.begin();
|
|
|
|
for (BitcodeModule &BM : BMs) {
|
|
Expected<BitcodeLTOInfo> LTOInfo = BM.getLTOInfo();
|
|
if (LTOInfo && LTOInfo->IsThinLTO)
|
|
return &BM;
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
Expected<BitcodeModule> lto::findThinLTOModule(MemoryBufferRef MBRef) {
|
|
Expected<std::vector<BitcodeModule>> BMsOrErr = getBitcodeModuleList(MBRef);
|
|
if (!BMsOrErr)
|
|
return BMsOrErr.takeError();
|
|
|
|
// The bitcode file may contain multiple modules, we want the one that is
|
|
// marked as being the ThinLTO module.
|
|
if (const BitcodeModule *Bm = lto::findThinLTOModule(*BMsOrErr))
|
|
return *Bm;
|
|
|
|
return make_error<StringError>("Could not find module summary",
|
|
inconvertibleErrorCode());
|
|
}
|
|
|
|
bool lto::loadReferencedModules(
|
|
const Module &M, const ModuleSummaryIndex &CombinedIndex,
|
|
FunctionImporter::ImportMapTy &ImportList,
|
|
MapVector<llvm::StringRef, llvm::BitcodeModule> &ModuleMap,
|
|
std::vector<std::unique_ptr<llvm::MemoryBuffer>>
|
|
&OwnedImportsLifetimeManager) {
|
|
if (ThinLTOAssumeMerged)
|
|
return true;
|
|
// We can simply import the values mentioned in the combined index, since
|
|
// we should only invoke this using the individual indexes written out
|
|
// via a WriteIndexesThinBackend.
|
|
for (const auto &GlobalList : CombinedIndex) {
|
|
// Ignore entries for undefined references.
|
|
if (GlobalList.second.SummaryList.empty())
|
|
continue;
|
|
|
|
auto GUID = GlobalList.first;
|
|
for (const auto &Summary : GlobalList.second.SummaryList) {
|
|
// Skip the summaries for the importing module. These are included to
|
|
// e.g. record required linkage changes.
|
|
if (Summary->modulePath() == M.getModuleIdentifier())
|
|
continue;
|
|
// Add an entry to provoke importing by thinBackend.
|
|
ImportList[Summary->modulePath()].insert(GUID);
|
|
}
|
|
}
|
|
|
|
for (auto &I : ImportList) {
|
|
ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> MBOrErr =
|
|
llvm::MemoryBuffer::getFile(I.first());
|
|
if (!MBOrErr) {
|
|
errs() << "Error loading imported file '" << I.first()
|
|
<< "': " << MBOrErr.getError().message() << "\n";
|
|
return false;
|
|
}
|
|
|
|
Expected<BitcodeModule> BMOrErr = findThinLTOModule(**MBOrErr);
|
|
if (!BMOrErr) {
|
|
handleAllErrors(BMOrErr.takeError(), [&](ErrorInfoBase &EIB) {
|
|
errs() << "Error loading imported file '" << I.first()
|
|
<< "': " << EIB.message() << '\n';
|
|
});
|
|
return false;
|
|
}
|
|
ModuleMap.insert({I.first(), *BMOrErr});
|
|
OwnedImportsLifetimeManager.push_back(std::move(*MBOrErr));
|
|
}
|
|
return true;
|
|
}
|