forked from OSchip/llvm-project
915 lines
34 KiB
C++
915 lines
34 KiB
C++
//===-LTO.cpp - LLVM Link Time Optimizer ----------------------------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements functions and classes used to support LTO.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/LTO/LTO.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/CodeGen/Analysis.h"
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#include "llvm/IR/AutoUpgrade.h"
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#include "llvm/IR/DiagnosticPrinter.h"
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#include "llvm/IR/LegacyPassManager.h"
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#include "llvm/LTO/LTOBackend.h"
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#include "llvm/Linker/IRMover.h"
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#include "llvm/Object/ModuleSummaryIndexObjectFile.h"
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#include "llvm/Support/ManagedStatic.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/SHA1.h"
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#include "llvm/Support/SourceMgr.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/Threading.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/Target/TargetOptions.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/Utils/SplitModule.h"
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#include <set>
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using namespace llvm;
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using namespace lto;
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using namespace object;
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#define DEBUG_TYPE "lto"
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// Returns a unique hash for the Module considering the current list of
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// export/import and other global analysis results.
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// The hash is produced in \p Key.
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static void computeCacheKey(
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SmallString<40> &Key, const Config &Conf, const ModuleSummaryIndex &Index,
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StringRef ModuleID, const FunctionImporter::ImportMapTy &ImportList,
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const FunctionImporter::ExportSetTy &ExportList,
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const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
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const GVSummaryMapTy &DefinedGlobals) {
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// Compute the unique hash for this entry.
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// This is based on the current compiler version, the module itself, the
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// export list, the hash for every single module in the import list, the
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// list of ResolvedODR for the module, and the list of preserved symbols.
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SHA1 Hasher;
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// Start with the compiler revision
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Hasher.update(LLVM_VERSION_STRING);
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#ifdef HAVE_LLVM_REVISION
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Hasher.update(LLVM_REVISION);
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#endif
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// Include the parts of the LTO configuration that affect code generation.
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auto AddString = [&](StringRef Str) {
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Hasher.update(Str);
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Hasher.update(ArrayRef<uint8_t>{0});
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};
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auto AddUnsigned = [&](unsigned I) {
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uint8_t Data[4];
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Data[0] = I;
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Data[1] = I >> 8;
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Data[2] = I >> 16;
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Data[3] = I >> 24;
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Hasher.update(ArrayRef<uint8_t>{Data, 4});
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};
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AddString(Conf.CPU);
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// FIXME: Hash more of Options. For now all clients initialize Options from
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// command-line flags (which is unsupported in production), but may set
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// RelaxELFRelocations. The clang driver can also pass FunctionSections,
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// DataSections and DebuggerTuning via command line flags.
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AddUnsigned(Conf.Options.RelaxELFRelocations);
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AddUnsigned(Conf.Options.FunctionSections);
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AddUnsigned(Conf.Options.DataSections);
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AddUnsigned((unsigned)Conf.Options.DebuggerTuning);
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for (auto &A : Conf.MAttrs)
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AddString(A);
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AddUnsigned(Conf.RelocModel);
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AddUnsigned(Conf.CodeModel);
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AddUnsigned(Conf.CGOptLevel);
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AddUnsigned(Conf.OptLevel);
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AddString(Conf.OptPipeline);
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AddString(Conf.AAPipeline);
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AddString(Conf.OverrideTriple);
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AddString(Conf.DefaultTriple);
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// Include the hash for the current module
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auto ModHash = Index.getModuleHash(ModuleID);
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Hasher.update(ArrayRef<uint8_t>((uint8_t *)&ModHash[0], sizeof(ModHash)));
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for (auto F : ExportList)
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// The export list can impact the internalization, be conservative here
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Hasher.update(ArrayRef<uint8_t>((uint8_t *)&F, sizeof(F)));
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// Include the hash for every module we import functions from
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for (auto &Entry : ImportList) {
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auto ModHash = Index.getModuleHash(Entry.first());
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Hasher.update(ArrayRef<uint8_t>((uint8_t *)&ModHash[0], sizeof(ModHash)));
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}
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// Include the hash for the resolved ODR.
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for (auto &Entry : ResolvedODR) {
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Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&Entry.first,
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sizeof(GlobalValue::GUID)));
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Hasher.update(ArrayRef<uint8_t>((const uint8_t *)&Entry.second,
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sizeof(GlobalValue::LinkageTypes)));
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}
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// Include the hash for the linkage type to reflect internalization and weak
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// resolution.
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for (auto &GS : DefinedGlobals) {
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GlobalValue::LinkageTypes Linkage = GS.second->linkage();
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Hasher.update(
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ArrayRef<uint8_t>((const uint8_t *)&Linkage, sizeof(Linkage)));
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}
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if (!Conf.SampleProfile.empty()) {
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auto FileOrErr = MemoryBuffer::getFile(Conf.SampleProfile);
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if (FileOrErr)
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Hasher.update(FileOrErr.get()->getBuffer());
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}
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Key = toHex(Hasher.result());
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}
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static void thinLTOResolveWeakForLinkerGUID(
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GlobalValueSummaryList &GVSummaryList, GlobalValue::GUID GUID,
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DenseSet<GlobalValueSummary *> &GlobalInvolvedWithAlias,
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function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)>
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isPrevailing,
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function_ref<void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)>
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recordNewLinkage) {
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for (auto &S : GVSummaryList) {
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GlobalValue::LinkageTypes OriginalLinkage = S->linkage();
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if (!GlobalValue::isWeakForLinker(OriginalLinkage))
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continue;
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// We need to emit only one of these. The prevailing module will keep it,
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// but turned into a weak, while the others will drop it when possible.
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// This is both a compile-time optimization and a correctness
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// transformation. This is necessary for correctness when we have exported
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// a reference - we need to convert the linkonce to weak to
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// ensure a copy is kept to satisfy the exported reference.
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// FIXME: We may want to split the compile time and correctness
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// aspects into separate routines.
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if (isPrevailing(GUID, S.get())) {
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if (GlobalValue::isLinkOnceLinkage(OriginalLinkage))
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S->setLinkage(GlobalValue::getWeakLinkage(
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GlobalValue::isLinkOnceODRLinkage(OriginalLinkage)));
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}
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// Alias and aliasee can't be turned into available_externally.
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else if (!isa<AliasSummary>(S.get()) &&
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!GlobalInvolvedWithAlias.count(S.get()) &&
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(GlobalValue::isLinkOnceODRLinkage(OriginalLinkage) ||
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GlobalValue::isWeakODRLinkage(OriginalLinkage)))
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S->setLinkage(GlobalValue::AvailableExternallyLinkage);
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if (S->linkage() != OriginalLinkage)
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recordNewLinkage(S->modulePath(), GUID, S->linkage());
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}
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}
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// Resolve Weak and LinkOnce values in the \p Index.
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//
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// We'd like to drop these functions if they are no longer referenced in the
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// current module. However there is a chance that another module is still
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// referencing them because of the import. We make sure we always emit at least
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// one copy.
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void llvm::thinLTOResolveWeakForLinkerInIndex(
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ModuleSummaryIndex &Index,
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function_ref<bool(GlobalValue::GUID, const GlobalValueSummary *)>
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isPrevailing,
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function_ref<void(StringRef, GlobalValue::GUID, GlobalValue::LinkageTypes)>
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recordNewLinkage) {
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// We won't optimize the globals that are referenced by an alias for now
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// Ideally we should turn the alias into a global and duplicate the definition
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// when needed.
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DenseSet<GlobalValueSummary *> GlobalInvolvedWithAlias;
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for (auto &I : Index)
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for (auto &S : I.second)
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if (auto AS = dyn_cast<AliasSummary>(S.get()))
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GlobalInvolvedWithAlias.insert(&AS->getAliasee());
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for (auto &I : Index)
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thinLTOResolveWeakForLinkerGUID(I.second, I.first, GlobalInvolvedWithAlias,
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isPrevailing, recordNewLinkage);
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}
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static void thinLTOInternalizeAndPromoteGUID(
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GlobalValueSummaryList &GVSummaryList, GlobalValue::GUID GUID,
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function_ref<bool(StringRef, GlobalValue::GUID)> isExported) {
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for (auto &S : GVSummaryList) {
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if (isExported(S->modulePath(), GUID)) {
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if (GlobalValue::isLocalLinkage(S->linkage()))
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S->setLinkage(GlobalValue::ExternalLinkage);
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} else if (!GlobalValue::isLocalLinkage(S->linkage()))
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S->setLinkage(GlobalValue::InternalLinkage);
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}
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}
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// Update the linkages in the given \p Index to mark exported values
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// as external and non-exported values as internal.
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void llvm::thinLTOInternalizeAndPromoteInIndex(
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ModuleSummaryIndex &Index,
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function_ref<bool(StringRef, GlobalValue::GUID)> isExported) {
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for (auto &I : Index)
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thinLTOInternalizeAndPromoteGUID(I.second, I.first, isExported);
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}
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struct InputFile::InputModule {
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BitcodeModule BM;
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std::unique_ptr<Module> Mod;
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// The range of ModuleSymbolTable entries for this input module.
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size_t SymBegin, SymEnd;
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};
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// Requires a destructor for std::vector<InputModule>.
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InputFile::~InputFile() = default;
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Expected<std::unique_ptr<InputFile>> InputFile::create(MemoryBufferRef Object) {
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std::unique_ptr<InputFile> File(new InputFile);
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ErrorOr<MemoryBufferRef> BCOrErr =
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IRObjectFile::findBitcodeInMemBuffer(Object);
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if (!BCOrErr)
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return errorCodeToError(BCOrErr.getError());
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Expected<std::vector<BitcodeModule>> BMsOrErr =
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getBitcodeModuleList(*BCOrErr);
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if (!BMsOrErr)
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return BMsOrErr.takeError();
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if (BMsOrErr->empty())
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return make_error<StringError>("Bitcode file does not contain any modules",
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inconvertibleErrorCode());
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// Create an InputModule for each module in the InputFile, and add it to the
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// ModuleSymbolTable.
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for (auto BM : *BMsOrErr) {
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Expected<std::unique_ptr<Module>> MOrErr =
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BM.getLazyModule(File->Ctx, /*ShouldLazyLoadMetadata*/ true,
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/*IsImporting*/ false);
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if (!MOrErr)
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return MOrErr.takeError();
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size_t SymBegin = File->SymTab.symbols().size();
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File->SymTab.addModule(MOrErr->get());
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size_t SymEnd = File->SymTab.symbols().size();
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for (const auto &C : (*MOrErr)->getComdatSymbolTable()) {
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auto P = File->ComdatMap.insert(
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std::make_pair(&C.second, File->Comdats.size()));
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assert(P.second);
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(void)P;
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File->Comdats.push_back(C.first());
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}
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File->Mods.push_back({BM, std::move(*MOrErr), SymBegin, SymEnd});
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}
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return std::move(File);
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}
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Expected<int> InputFile::Symbol::getComdatIndex() const {
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if (!isGV())
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return -1;
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const GlobalObject *GO = getGV()->getBaseObject();
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if (!GO)
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return make_error<StringError>("Unable to determine comdat of alias!",
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inconvertibleErrorCode());
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if (const Comdat *C = GO->getComdat()) {
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auto I = File->ComdatMap.find(C);
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assert(I != File->ComdatMap.end());
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return I->second;
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}
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return -1;
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}
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StringRef InputFile::getName() const {
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return Mods[0].BM.getModuleIdentifier();
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}
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StringRef InputFile::getSourceFileName() const {
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return Mods[0].Mod->getSourceFileName();
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}
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iterator_range<InputFile::symbol_iterator>
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InputFile::module_symbols(InputModule &IM) {
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return llvm::make_range(
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symbol_iterator(SymTab.symbols().data() + IM.SymBegin, SymTab, this),
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symbol_iterator(SymTab.symbols().data() + IM.SymEnd, SymTab, this));
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}
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LTO::RegularLTOState::RegularLTOState(unsigned ParallelCodeGenParallelismLevel,
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Config &Conf)
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: ParallelCodeGenParallelismLevel(ParallelCodeGenParallelismLevel),
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Ctx(Conf) {}
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LTO::ThinLTOState::ThinLTOState(ThinBackend Backend) : Backend(Backend) {
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if (!Backend)
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this->Backend =
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createInProcessThinBackend(llvm::heavyweight_hardware_concurrency());
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}
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LTO::LTO(Config Conf, ThinBackend Backend,
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unsigned ParallelCodeGenParallelismLevel)
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: Conf(std::move(Conf)),
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RegularLTO(ParallelCodeGenParallelismLevel, this->Conf),
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ThinLTO(std::move(Backend)) {}
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// Requires a destructor for MapVector<BitcodeModule>.
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LTO::~LTO() = default;
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// Add the given symbol to the GlobalResolutions map, and resolve its partition.
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void LTO::addSymbolToGlobalRes(SmallPtrSet<GlobalValue *, 8> &Used,
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const InputFile::Symbol &Sym,
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SymbolResolution Res, unsigned Partition) {
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GlobalValue *GV = Sym.isGV() ? Sym.getGV() : nullptr;
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auto &GlobalRes = GlobalResolutions[Sym.getName()];
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if (GV) {
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GlobalRes.UnnamedAddr &= GV->hasGlobalUnnamedAddr();
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if (Res.Prevailing)
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GlobalRes.IRName = GV->getName();
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}
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if (Res.VisibleToRegularObj || (GV && Used.count(GV)) ||
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(GlobalRes.Partition != GlobalResolution::Unknown &&
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GlobalRes.Partition != Partition))
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GlobalRes.Partition = GlobalResolution::External;
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else
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GlobalRes.Partition = Partition;
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}
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static void writeToResolutionFile(raw_ostream &OS, InputFile *Input,
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ArrayRef<SymbolResolution> Res) {
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StringRef Path = Input->getName();
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OS << Path << '\n';
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auto ResI = Res.begin();
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for (const InputFile::Symbol &Sym : Input->symbols()) {
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assert(ResI != Res.end());
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SymbolResolution Res = *ResI++;
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OS << "-r=" << Path << ',' << Sym.getName() << ',';
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if (Res.Prevailing)
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OS << 'p';
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if (Res.FinalDefinitionInLinkageUnit)
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OS << 'l';
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if (Res.VisibleToRegularObj)
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OS << 'x';
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OS << '\n';
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}
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assert(ResI == Res.end());
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}
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Error LTO::add(std::unique_ptr<InputFile> Input,
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ArrayRef<SymbolResolution> Res) {
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assert(!CalledGetMaxTasks);
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if (Conf.ResolutionFile)
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writeToResolutionFile(*Conf.ResolutionFile, Input.get(), Res);
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const SymbolResolution *ResI = Res.begin();
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for (InputFile::InputModule &IM : Input->Mods)
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if (Error Err = addModule(*Input, IM, ResI, Res.end()))
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return Err;
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assert(ResI == Res.end());
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return Error::success();
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}
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Error LTO::addModule(InputFile &Input, InputFile::InputModule &IM,
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const SymbolResolution *&ResI,
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const SymbolResolution *ResE) {
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// FIXME: move to backend
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Module &M = *IM.Mod;
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if (M.getDataLayoutStr().empty())
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return make_error<StringError>("input module has no datalayout",
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inconvertibleErrorCode());
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if (!Conf.OverrideTriple.empty())
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M.setTargetTriple(Conf.OverrideTriple);
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else if (M.getTargetTriple().empty())
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M.setTargetTriple(Conf.DefaultTriple);
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Expected<bool> HasThinLTOSummary = IM.BM.hasSummary();
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if (!HasThinLTOSummary)
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return HasThinLTOSummary.takeError();
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if (*HasThinLTOSummary)
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return addThinLTO(IM.BM, M, Input.module_symbols(IM), ResI, ResE);
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else
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return addRegularLTO(IM.BM, ResI, ResE);
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}
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// Add a regular LTO object to the link.
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Error LTO::addRegularLTO(BitcodeModule BM, const SymbolResolution *&ResI,
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const SymbolResolution *ResE) {
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if (!RegularLTO.CombinedModule) {
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RegularLTO.CombinedModule =
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llvm::make_unique<Module>("ld-temp.o", RegularLTO.Ctx);
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RegularLTO.Mover = llvm::make_unique<IRMover>(*RegularLTO.CombinedModule);
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}
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Expected<std::unique_ptr<Module>> MOrErr =
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BM.getLazyModule(RegularLTO.Ctx, /*ShouldLazyLoadMetadata*/ true,
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/*IsImporting*/ false);
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if (!MOrErr)
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return MOrErr.takeError();
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Module &M = **MOrErr;
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if (Error Err = M.materializeMetadata())
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return Err;
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UpgradeDebugInfo(M);
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ModuleSymbolTable SymTab;
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SymTab.addModule(&M);
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SmallPtrSet<GlobalValue *, 8> Used;
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collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false);
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std::vector<GlobalValue *> Keep;
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for (GlobalVariable &GV : M.globals())
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if (GV.hasAppendingLinkage())
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Keep.push_back(&GV);
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for (const InputFile::Symbol &Sym :
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make_range(InputFile::symbol_iterator(SymTab.symbols().begin(), SymTab,
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nullptr),
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InputFile::symbol_iterator(SymTab.symbols().end(), SymTab,
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nullptr))) {
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assert(ResI != ResE);
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SymbolResolution Res = *ResI++;
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addSymbolToGlobalRes(Used, Sym, Res, 0);
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if (Sym.getFlags() & object::BasicSymbolRef::SF_Undefined)
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continue;
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if (Res.Prevailing && Sym.isGV()) {
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GlobalValue *GV = Sym.getGV();
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Keep.push_back(GV);
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switch (GV->getLinkage()) {
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default:
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break;
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case GlobalValue::LinkOnceAnyLinkage:
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GV->setLinkage(GlobalValue::WeakAnyLinkage);
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break;
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case GlobalValue::LinkOnceODRLinkage:
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GV->setLinkage(GlobalValue::WeakODRLinkage);
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break;
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}
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}
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// Common resolution: collect the maximum size/alignment over all commons.
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// We also record if we see an instance of a common as prevailing, so that
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// if none is prevailing we can ignore it later.
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if (Sym.getFlags() & object::BasicSymbolRef::SF_Common) {
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// FIXME: We should figure out what to do about commons defined by asm.
|
|
// For now they aren't reported correctly by ModuleSymbolTable.
|
|
auto &CommonRes = RegularLTO.Commons[Sym.getGV()->getName()];
|
|
CommonRes.Size = std::max(CommonRes.Size, Sym.getCommonSize());
|
|
CommonRes.Align = std::max(CommonRes.Align, Sym.getCommonAlignment());
|
|
CommonRes.Prevailing |= Res.Prevailing;
|
|
}
|
|
|
|
// FIXME: use proposed local attribute for FinalDefinitionInLinkageUnit.
|
|
}
|
|
|
|
return RegularLTO.Mover->move(std::move(*MOrErr), Keep,
|
|
[](GlobalValue &, IRMover::ValueAdder) {},
|
|
/* LinkModuleInlineAsm */ true,
|
|
/* IsPerformingImport */ false);
|
|
}
|
|
|
|
// Add a ThinLTO object to the link.
|
|
// FIXME: This function should not need to take as many parameters once we have
|
|
// a bitcode symbol table.
|
|
Error LTO::addThinLTO(BitcodeModule BM, Module &M,
|
|
iterator_range<InputFile::symbol_iterator> Syms,
|
|
const SymbolResolution *&ResI,
|
|
const SymbolResolution *ResE) {
|
|
SmallPtrSet<GlobalValue *, 8> Used;
|
|
collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false);
|
|
|
|
Expected<std::unique_ptr<ModuleSummaryIndex>> SummaryOrErr = BM.getSummary();
|
|
if (!SummaryOrErr)
|
|
return SummaryOrErr.takeError();
|
|
ThinLTO.CombinedIndex.mergeFrom(std::move(*SummaryOrErr),
|
|
ThinLTO.ModuleMap.size());
|
|
|
|
for (const InputFile::Symbol &Sym : Syms) {
|
|
assert(ResI != ResE);
|
|
SymbolResolution Res = *ResI++;
|
|
addSymbolToGlobalRes(Used, Sym, Res, ThinLTO.ModuleMap.size() + 1);
|
|
|
|
if (Res.Prevailing && Sym.isGV())
|
|
ThinLTO.PrevailingModuleForGUID[Sym.getGV()->getGUID()] =
|
|
BM.getModuleIdentifier();
|
|
}
|
|
|
|
if (!ThinLTO.ModuleMap.insert({BM.getModuleIdentifier(), BM}).second)
|
|
return make_error<StringError>(
|
|
"Expected at most one ThinLTO module per bitcode file",
|
|
inconvertibleErrorCode());
|
|
|
|
return Error::success();
|
|
}
|
|
|
|
unsigned LTO::getMaxTasks() const {
|
|
CalledGetMaxTasks = true;
|
|
return RegularLTO.ParallelCodeGenParallelismLevel + ThinLTO.ModuleMap.size();
|
|
}
|
|
|
|
Error LTO::run(AddStreamFn AddStream, NativeObjectCache Cache) {
|
|
// Save the status of having a regularLTO combined module, as
|
|
// this is needed for generating the ThinLTO Task ID, and
|
|
// the CombinedModule will be moved at the end of runRegularLTO.
|
|
bool HasRegularLTO = RegularLTO.CombinedModule != nullptr;
|
|
// Invoke regular LTO if there was a regular LTO module to start with.
|
|
if (HasRegularLTO)
|
|
if (auto E = runRegularLTO(AddStream))
|
|
return E;
|
|
return runThinLTO(AddStream, Cache, HasRegularLTO);
|
|
}
|
|
|
|
Error LTO::runRegularLTO(AddStreamFn AddStream) {
|
|
// Make sure commons have the right size/alignment: we kept the largest from
|
|
// all the prevailing when adding the inputs, and we apply it here.
|
|
const DataLayout &DL = RegularLTO.CombinedModule->getDataLayout();
|
|
for (auto &I : RegularLTO.Commons) {
|
|
if (!I.second.Prevailing)
|
|
// Don't do anything if no instance of this common was prevailing.
|
|
continue;
|
|
GlobalVariable *OldGV = RegularLTO.CombinedModule->getNamedGlobal(I.first);
|
|
if (OldGV && DL.getTypeAllocSize(OldGV->getValueType()) == I.second.Size) {
|
|
// Don't create a new global if the type is already correct, just make
|
|
// sure the alignment is correct.
|
|
OldGV->setAlignment(I.second.Align);
|
|
continue;
|
|
}
|
|
ArrayType *Ty =
|
|
ArrayType::get(Type::getInt8Ty(RegularLTO.Ctx), I.second.Size);
|
|
auto *GV = new GlobalVariable(*RegularLTO.CombinedModule, Ty, false,
|
|
GlobalValue::CommonLinkage,
|
|
ConstantAggregateZero::get(Ty), "");
|
|
GV->setAlignment(I.second.Align);
|
|
if (OldGV) {
|
|
OldGV->replaceAllUsesWith(ConstantExpr::getBitCast(GV, OldGV->getType()));
|
|
GV->takeName(OldGV);
|
|
OldGV->eraseFromParent();
|
|
} else {
|
|
GV->setName(I.first);
|
|
}
|
|
}
|
|
|
|
if (Conf.PreOptModuleHook &&
|
|
!Conf.PreOptModuleHook(0, *RegularLTO.CombinedModule))
|
|
return Error::success();
|
|
|
|
if (!Conf.CodeGenOnly) {
|
|
for (const auto &R : GlobalResolutions) {
|
|
if (R.second.IRName.empty())
|
|
continue;
|
|
if (R.second.Partition != 0 &&
|
|
R.second.Partition != GlobalResolution::External)
|
|
continue;
|
|
|
|
GlobalValue *GV =
|
|
RegularLTO.CombinedModule->getNamedValue(R.second.IRName);
|
|
// Ignore symbols defined in other partitions.
|
|
if (!GV || GV->hasLocalLinkage())
|
|
continue;
|
|
GV->setUnnamedAddr(R.second.UnnamedAddr ? GlobalValue::UnnamedAddr::Global
|
|
: GlobalValue::UnnamedAddr::None);
|
|
if (R.second.Partition == 0)
|
|
GV->setLinkage(GlobalValue::InternalLinkage);
|
|
}
|
|
|
|
if (Conf.PostInternalizeModuleHook &&
|
|
!Conf.PostInternalizeModuleHook(0, *RegularLTO.CombinedModule))
|
|
return Error::success();
|
|
}
|
|
return backend(Conf, AddStream, RegularLTO.ParallelCodeGenParallelismLevel,
|
|
std::move(RegularLTO.CombinedModule));
|
|
}
|
|
|
|
/// This class defines the interface to the ThinLTO backend.
|
|
class lto::ThinBackendProc {
|
|
protected:
|
|
Config &Conf;
|
|
ModuleSummaryIndex &CombinedIndex;
|
|
const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries;
|
|
|
|
public:
|
|
ThinBackendProc(Config &Conf, ModuleSummaryIndex &CombinedIndex,
|
|
const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries)
|
|
: Conf(Conf), CombinedIndex(CombinedIndex),
|
|
ModuleToDefinedGVSummaries(ModuleToDefinedGVSummaries) {}
|
|
|
|
virtual ~ThinBackendProc() {}
|
|
virtual Error start(
|
|
unsigned Task, BitcodeModule BM,
|
|
const FunctionImporter::ImportMapTy &ImportList,
|
|
const FunctionImporter::ExportSetTy &ExportList,
|
|
const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
|
|
MapVector<StringRef, BitcodeModule> &ModuleMap) = 0;
|
|
virtual Error wait() = 0;
|
|
};
|
|
|
|
namespace {
|
|
class InProcessThinBackend : public ThinBackendProc {
|
|
ThreadPool BackendThreadPool;
|
|
AddStreamFn AddStream;
|
|
NativeObjectCache Cache;
|
|
|
|
Optional<Error> Err;
|
|
std::mutex ErrMu;
|
|
|
|
public:
|
|
InProcessThinBackend(
|
|
Config &Conf, ModuleSummaryIndex &CombinedIndex,
|
|
unsigned ThinLTOParallelismLevel,
|
|
const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries,
|
|
AddStreamFn AddStream, NativeObjectCache Cache)
|
|
: ThinBackendProc(Conf, CombinedIndex, ModuleToDefinedGVSummaries),
|
|
BackendThreadPool(ThinLTOParallelismLevel),
|
|
AddStream(std::move(AddStream)), Cache(std::move(Cache)) {}
|
|
|
|
Error runThinLTOBackendThread(
|
|
AddStreamFn AddStream, NativeObjectCache Cache, unsigned Task,
|
|
BitcodeModule BM, ModuleSummaryIndex &CombinedIndex,
|
|
const FunctionImporter::ImportMapTy &ImportList,
|
|
const FunctionImporter::ExportSetTy &ExportList,
|
|
const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
|
|
const GVSummaryMapTy &DefinedGlobals,
|
|
MapVector<StringRef, BitcodeModule> &ModuleMap) {
|
|
auto RunThinBackend = [&](AddStreamFn AddStream) {
|
|
LTOLLVMContext BackendContext(Conf);
|
|
Expected<std::unique_ptr<Module>> MOrErr = BM.parseModule(BackendContext);
|
|
if (!MOrErr)
|
|
return MOrErr.takeError();
|
|
|
|
return thinBackend(Conf, Task, AddStream, **MOrErr, CombinedIndex,
|
|
ImportList, DefinedGlobals, ModuleMap);
|
|
};
|
|
|
|
auto ModuleID = BM.getModuleIdentifier();
|
|
|
|
if (!Cache || !CombinedIndex.modulePaths().count(ModuleID) ||
|
|
all_of(CombinedIndex.getModuleHash(ModuleID),
|
|
[](uint32_t V) { return V == 0; }))
|
|
// Cache disabled or no entry for this module in the combined index or
|
|
// no module hash.
|
|
return RunThinBackend(AddStream);
|
|
|
|
SmallString<40> Key;
|
|
// The module may be cached, this helps handling it.
|
|
computeCacheKey(Key, Conf, CombinedIndex, ModuleID, ImportList, ExportList,
|
|
ResolvedODR, DefinedGlobals);
|
|
if (AddStreamFn CacheAddStream = Cache(Task, Key))
|
|
return RunThinBackend(CacheAddStream);
|
|
|
|
return Error::success();
|
|
}
|
|
|
|
Error start(
|
|
unsigned Task, BitcodeModule BM,
|
|
const FunctionImporter::ImportMapTy &ImportList,
|
|
const FunctionImporter::ExportSetTy &ExportList,
|
|
const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
|
|
MapVector<StringRef, BitcodeModule> &ModuleMap) override {
|
|
StringRef ModulePath = BM.getModuleIdentifier();
|
|
assert(ModuleToDefinedGVSummaries.count(ModulePath));
|
|
const GVSummaryMapTy &DefinedGlobals =
|
|
ModuleToDefinedGVSummaries.find(ModulePath)->second;
|
|
BackendThreadPool.async(
|
|
[=](BitcodeModule BM, ModuleSummaryIndex &CombinedIndex,
|
|
const FunctionImporter::ImportMapTy &ImportList,
|
|
const FunctionImporter::ExportSetTy &ExportList,
|
|
const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes>
|
|
&ResolvedODR,
|
|
const GVSummaryMapTy &DefinedGlobals,
|
|
MapVector<StringRef, BitcodeModule> &ModuleMap) {
|
|
Error E = runThinLTOBackendThread(
|
|
AddStream, Cache, Task, BM, CombinedIndex, ImportList,
|
|
ExportList, ResolvedODR, DefinedGlobals, ModuleMap);
|
|
if (E) {
|
|
std::unique_lock<std::mutex> L(ErrMu);
|
|
if (Err)
|
|
Err = joinErrors(std::move(*Err), std::move(E));
|
|
else
|
|
Err = std::move(E);
|
|
}
|
|
},
|
|
BM, std::ref(CombinedIndex), std::ref(ImportList),
|
|
std::ref(ExportList), std::ref(ResolvedODR), std::ref(DefinedGlobals),
|
|
std::ref(ModuleMap));
|
|
return Error::success();
|
|
}
|
|
|
|
Error wait() override {
|
|
BackendThreadPool.wait();
|
|
if (Err)
|
|
return std::move(*Err);
|
|
else
|
|
return Error::success();
|
|
}
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
ThinBackend lto::createInProcessThinBackend(unsigned ParallelismLevel) {
|
|
return [=](Config &Conf, ModuleSummaryIndex &CombinedIndex,
|
|
const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries,
|
|
AddStreamFn AddStream, NativeObjectCache Cache) {
|
|
return llvm::make_unique<InProcessThinBackend>(
|
|
Conf, CombinedIndex, ParallelismLevel, ModuleToDefinedGVSummaries,
|
|
AddStream, Cache);
|
|
};
|
|
}
|
|
|
|
// Given the original \p Path to an output file, replace any path
|
|
// prefix matching \p OldPrefix with \p NewPrefix. Also, create the
|
|
// resulting directory if it does not yet exist.
|
|
std::string lto::getThinLTOOutputFile(const std::string &Path,
|
|
const std::string &OldPrefix,
|
|
const std::string &NewPrefix) {
|
|
if (OldPrefix.empty() && NewPrefix.empty())
|
|
return Path;
|
|
SmallString<128> NewPath(Path);
|
|
llvm::sys::path::replace_path_prefix(NewPath, OldPrefix, NewPrefix);
|
|
StringRef ParentPath = llvm::sys::path::parent_path(NewPath.str());
|
|
if (!ParentPath.empty()) {
|
|
// Make sure the new directory exists, creating it if necessary.
|
|
if (std::error_code EC = llvm::sys::fs::create_directories(ParentPath))
|
|
llvm::errs() << "warning: could not create directory '" << ParentPath
|
|
<< "': " << EC.message() << '\n';
|
|
}
|
|
return NewPath.str();
|
|
}
|
|
|
|
namespace {
|
|
class WriteIndexesThinBackend : public ThinBackendProc {
|
|
std::string OldPrefix, NewPrefix;
|
|
bool ShouldEmitImportsFiles;
|
|
|
|
std::string LinkedObjectsFileName;
|
|
std::unique_ptr<llvm::raw_fd_ostream> LinkedObjectsFile;
|
|
|
|
public:
|
|
WriteIndexesThinBackend(
|
|
Config &Conf, ModuleSummaryIndex &CombinedIndex,
|
|
const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries,
|
|
std::string OldPrefix, std::string NewPrefix, bool ShouldEmitImportsFiles,
|
|
std::string LinkedObjectsFileName)
|
|
: ThinBackendProc(Conf, CombinedIndex, ModuleToDefinedGVSummaries),
|
|
OldPrefix(OldPrefix), NewPrefix(NewPrefix),
|
|
ShouldEmitImportsFiles(ShouldEmitImportsFiles),
|
|
LinkedObjectsFileName(LinkedObjectsFileName) {}
|
|
|
|
Error start(
|
|
unsigned Task, BitcodeModule BM,
|
|
const FunctionImporter::ImportMapTy &ImportList,
|
|
const FunctionImporter::ExportSetTy &ExportList,
|
|
const std::map<GlobalValue::GUID, GlobalValue::LinkageTypes> &ResolvedODR,
|
|
MapVector<StringRef, BitcodeModule> &ModuleMap) override {
|
|
StringRef ModulePath = BM.getModuleIdentifier();
|
|
std::string NewModulePath =
|
|
getThinLTOOutputFile(ModulePath, OldPrefix, NewPrefix);
|
|
|
|
std::error_code EC;
|
|
if (!LinkedObjectsFileName.empty()) {
|
|
if (!LinkedObjectsFile) {
|
|
LinkedObjectsFile = llvm::make_unique<raw_fd_ostream>(
|
|
LinkedObjectsFileName, EC, sys::fs::OpenFlags::F_None);
|
|
if (EC)
|
|
return errorCodeToError(EC);
|
|
}
|
|
*LinkedObjectsFile << NewModulePath << '\n';
|
|
}
|
|
|
|
std::map<std::string, GVSummaryMapTy> ModuleToSummariesForIndex;
|
|
gatherImportedSummariesForModule(ModulePath, ModuleToDefinedGVSummaries,
|
|
ImportList, ModuleToSummariesForIndex);
|
|
|
|
raw_fd_ostream OS(NewModulePath + ".thinlto.bc", EC,
|
|
sys::fs::OpenFlags::F_None);
|
|
if (EC)
|
|
return errorCodeToError(EC);
|
|
WriteIndexToFile(CombinedIndex, OS, &ModuleToSummariesForIndex);
|
|
|
|
if (ShouldEmitImportsFiles)
|
|
return errorCodeToError(
|
|
EmitImportsFiles(ModulePath, NewModulePath + ".imports", ImportList));
|
|
return Error::success();
|
|
}
|
|
|
|
Error wait() override { return Error::success(); }
|
|
};
|
|
} // end anonymous namespace
|
|
|
|
ThinBackend lto::createWriteIndexesThinBackend(std::string OldPrefix,
|
|
std::string NewPrefix,
|
|
bool ShouldEmitImportsFiles,
|
|
std::string LinkedObjectsFile) {
|
|
return [=](Config &Conf, ModuleSummaryIndex &CombinedIndex,
|
|
const StringMap<GVSummaryMapTy> &ModuleToDefinedGVSummaries,
|
|
AddStreamFn AddStream, NativeObjectCache Cache) {
|
|
return llvm::make_unique<WriteIndexesThinBackend>(
|
|
Conf, CombinedIndex, ModuleToDefinedGVSummaries, OldPrefix, NewPrefix,
|
|
ShouldEmitImportsFiles, LinkedObjectsFile);
|
|
};
|
|
}
|
|
|
|
Error LTO::runThinLTO(AddStreamFn AddStream, NativeObjectCache Cache,
|
|
bool HasRegularLTO) {
|
|
if (ThinLTO.ModuleMap.empty())
|
|
return Error::success();
|
|
|
|
if (Conf.CombinedIndexHook && !Conf.CombinedIndexHook(ThinLTO.CombinedIndex))
|
|
return Error::success();
|
|
|
|
// Collect for each module the list of function it defines (GUID ->
|
|
// Summary).
|
|
StringMap<std::map<GlobalValue::GUID, GlobalValueSummary *>>
|
|
ModuleToDefinedGVSummaries(ThinLTO.ModuleMap.size());
|
|
ThinLTO.CombinedIndex.collectDefinedGVSummariesPerModule(
|
|
ModuleToDefinedGVSummaries);
|
|
// Create entries for any modules that didn't have any GV summaries
|
|
// (either they didn't have any GVs to start with, or we suppressed
|
|
// generation of the summaries because they e.g. had inline assembly
|
|
// uses that couldn't be promoted/renamed on export). This is so
|
|
// InProcessThinBackend::start can still launch a backend thread, which
|
|
// is passed the map of summaries for the module, without any special
|
|
// handling for this case.
|
|
for (auto &Mod : ThinLTO.ModuleMap)
|
|
if (!ModuleToDefinedGVSummaries.count(Mod.first))
|
|
ModuleToDefinedGVSummaries.try_emplace(Mod.first);
|
|
|
|
StringMap<FunctionImporter::ImportMapTy> ImportLists(
|
|
ThinLTO.ModuleMap.size());
|
|
StringMap<FunctionImporter::ExportSetTy> ExportLists(
|
|
ThinLTO.ModuleMap.size());
|
|
StringMap<std::map<GlobalValue::GUID, GlobalValue::LinkageTypes>> ResolvedODR;
|
|
|
|
if (Conf.OptLevel > 0) {
|
|
ComputeCrossModuleImport(ThinLTO.CombinedIndex, ModuleToDefinedGVSummaries,
|
|
ImportLists, ExportLists);
|
|
|
|
std::set<GlobalValue::GUID> ExportedGUIDs;
|
|
for (auto &Res : GlobalResolutions) {
|
|
if (!Res.second.IRName.empty() &&
|
|
Res.second.Partition == GlobalResolution::External)
|
|
ExportedGUIDs.insert(GlobalValue::getGUID(Res.second.IRName));
|
|
}
|
|
|
|
auto isPrevailing = [&](GlobalValue::GUID GUID,
|
|
const GlobalValueSummary *S) {
|
|
return ThinLTO.PrevailingModuleForGUID[GUID] == S->modulePath();
|
|
};
|
|
auto isExported = [&](StringRef ModuleIdentifier, GlobalValue::GUID GUID) {
|
|
const auto &ExportList = ExportLists.find(ModuleIdentifier);
|
|
return (ExportList != ExportLists.end() &&
|
|
ExportList->second.count(GUID)) ||
|
|
ExportedGUIDs.count(GUID);
|
|
};
|
|
thinLTOInternalizeAndPromoteInIndex(ThinLTO.CombinedIndex, isExported);
|
|
|
|
auto recordNewLinkage = [&](StringRef ModuleIdentifier,
|
|
GlobalValue::GUID GUID,
|
|
GlobalValue::LinkageTypes NewLinkage) {
|
|
ResolvedODR[ModuleIdentifier][GUID] = NewLinkage;
|
|
};
|
|
|
|
thinLTOResolveWeakForLinkerInIndex(ThinLTO.CombinedIndex, isPrevailing,
|
|
recordNewLinkage);
|
|
}
|
|
|
|
std::unique_ptr<ThinBackendProc> BackendProc =
|
|
ThinLTO.Backend(Conf, ThinLTO.CombinedIndex, ModuleToDefinedGVSummaries,
|
|
AddStream, Cache);
|
|
|
|
// Partition numbers for ThinLTO jobs start at 1 (see comments for
|
|
// GlobalResolution in LTO.h). Task numbers, however, start at
|
|
// ParallelCodeGenParallelismLevel if an LTO module is present, as tasks 0
|
|
// through ParallelCodeGenParallelismLevel-1 are reserved for parallel code
|
|
// generation partitions.
|
|
unsigned Task =
|
|
HasRegularLTO ? RegularLTO.ParallelCodeGenParallelismLevel : 0;
|
|
unsigned Partition = 1;
|
|
|
|
for (auto &Mod : ThinLTO.ModuleMap) {
|
|
if (Error E = BackendProc->start(Task, Mod.second, ImportLists[Mod.first],
|
|
ExportLists[Mod.first],
|
|
ResolvedODR[Mod.first], ThinLTO.ModuleMap))
|
|
return E;
|
|
|
|
++Task;
|
|
++Partition;
|
|
}
|
|
|
|
return BackendProc->wait();
|
|
}
|