LLVM 22.0.0git
Classes | Typedefs | Functions
llvm::lto Namespace Reference

Classes

struct  Config
 LTO configuration. More...
 
class  InputFile
 An input file. More...
 
class  LTO
 This class implements a resolution-based interface to LLVM's LTO functionality. More...
 
struct  LTOLLVMContext
 A derived class of LLVMContext that initializes itself according to a given Config object. More...
 
struct  LTOLLVMDiagnosticHandler
 
struct  SymbolResolution
 The resolution for a symbol. More...
 
struct  ThinBackend
 This type defines the behavior following the thin-link phase during ThinLTO. More...
 
class  ThinBackendProc
 This class defines the interface to the ThinLTO backend. More...
 

Typedefs

using IndexWriteCallback = std::function< void(const std::string &)>
 
using ImportsFilesContainer = llvm::SmallVector< std::string >
 
using ThinBackendFunction = std::function< std::unique_ptr< ThinBackendProc >(const Config &C, ModuleSummaryIndex &CombinedIndex, const DenseMap< StringRef, GVSummaryMapTy > &ModuleToDefinedGVSummaries, AddStreamFn AddStream, FileCache Cache)>
 This callable defines the behavior of a ThinLTO backend after the thin-link phase.
 

Functions

LLVM_ABI StringLiteral getThinLTODefaultCPU (const Triple &TheTriple)
 
LLVM_ABI std::string getThinLTOOutputFile (StringRef Path, StringRef OldPrefix, StringRef NewPrefix)
 Given the original Path to an output file, replace any path prefix matching OldPrefix with NewPrefix.
 
LLVM_ABI Expected< std::unique_ptr< ToolOutputFile > > setupLLVMOptimizationRemarks (LLVMContext &Context, StringRef RemarksFilename, StringRef RemarksPasses, StringRef RemarksFormat, bool RemarksWithHotness, std::optional< uint64_t > RemarksHotnessThreshold=0, int Count=-1)
 Setup optimization remarks.
 
LLVM_ABI Expected< std::unique_ptr< ToolOutputFile > > setupStatsFile (StringRef StatsFilename)
 Setups the output file for saving statistics.
 
LLVM_ABI std::vector< int > generateModulesOrdering (ArrayRef< BitcodeModule * > R)
 Produces a container ordering for optimal multi-threaded processing.
 
LLVM_ABI void updateMemProfAttributes (Module &Mod, const ModuleSummaryIndex &Index)
 Updates MemProf attributes (and metadata) based on whether the index has recorded that we are linking with allocation libraries containing the necessary APIs for downstream transformations.
 
LLVM_ABI ThinBackend createInProcessThinBackend (ThreadPoolStrategy Parallelism, IndexWriteCallback OnWrite=nullptr, bool ShouldEmitIndexFiles=false, bool ShouldEmitImportsFiles=false)
 This ThinBackend runs the individual backend jobs in-process.
 
LLVM_ABI ThinBackend createOutOfProcessThinBackend (ThreadPoolStrategy Parallelism, IndexWriteCallback OnWrite, bool ShouldEmitIndexFiles, bool ShouldEmitImportsFiles, StringRef LinkerOutputFile, StringRef Distributor, ArrayRef< StringRef > DistributorArgs, StringRef RemoteCompiler, ArrayRef< StringRef > RemoteCompilerArgs, bool SaveTemps)
 This ThinBackend generates the index shards and then runs the individual backend jobs via an external process.
 
LLVM_ABI ThinBackend createWriteIndexesThinBackend (ThreadPoolStrategy Parallelism, std::string OldPrefix, std::string NewPrefix, std::string NativeObjectPrefix, bool ShouldEmitImportsFiles, raw_fd_ostream *LinkedObjectsFile, IndexWriteCallback OnWrite)
 This ThinBackend writes individual module indexes to files, instead of running the individual backend jobs.
 
LLVM_ABI bool opt (const Config &Conf, TargetMachine *TM, unsigned Task, Module &Mod, bool IsThinLTO, ModuleSummaryIndex *ExportSummary, const ModuleSummaryIndex *ImportSummary, const std::vector< uint8_t > &CmdArgs)
 Runs middle-end LTO optimizations on Mod.
 
LLVM_ABI Error backend (const Config &C, AddStreamFn AddStream, unsigned ParallelCodeGenParallelismLevel, Module &M, ModuleSummaryIndex &CombinedIndex)
 Runs a regular LTO backend.
 
LLVM_ABI Error thinBackend (const Config &C, unsigned Task, AddStreamFn AddStream, Module &M, const ModuleSummaryIndex &CombinedIndex, const FunctionImporter::ImportMapTy &ImportList, const GVSummaryMapTy &DefinedGlobals, MapVector< StringRef, BitcodeModule > *ModuleMap, bool CodeGenOnly, AddStreamFn IRAddStream=nullptr, const std::vector< uint8_t > &CmdArgs=std::vector< uint8_t >())
 Runs a ThinLTO backend.
 
LLVM_ABI Error finalizeOptimizationRemarks (std::unique_ptr< ToolOutputFile > DiagOutputFile)
 
LLVM_ABI BitcodeModulefindThinLTOModule (MutableArrayRef< BitcodeModule > BMs)
 Returns the BitcodeModule that is ThinLTO.
 
LLVM_ABI Expected< BitcodeModulefindThinLTOModule (MemoryBufferRef MBRef)
 Variant of the above.
 
LLVM_ABI bool initImportList (const Module &M, const ModuleSummaryIndex &CombinedIndex, FunctionImporter::ImportMapTy &ImportList)
 Distributed ThinLTO: collect the referenced modules based on module summary and initialize ImportList.
 

Typedef Documentation

◆ ImportsFilesContainer

Definition at line 206 of file LTO.h.

◆ IndexWriteCallback

using llvm::lto::IndexWriteCallback = typedef std::function<void(const std::string &)>

Definition at line 204 of file LTO.h.

◆ ThinBackendFunction

using llvm::lto::ThinBackendFunction = typedef std::function<std::unique_ptr<ThinBackendProc>( const Config &C, ModuleSummaryIndex &CombinedIndex, const DenseMap<StringRef, GVSummaryMapTy> &ModuleToDefinedGVSummaries, AddStreamFn AddStream, FileCache Cache)>

This callable defines the behavior of a ThinLTO backend after the thin-link phase.

It accepts a configuration C, a combined module summary index CombinedIndex, a map of module identifiers to global variable summaries ModuleToDefinedGVSummaries, a function to add output streams AddStream, and a file cache Cache. It returns a unique pointer to a ThinBackendProc, which can be used to launch backends in parallel.

Definition at line 269 of file LTO.h.

Function Documentation

◆ backend()

Error llvm::lto::backend ( const Config C,
AddStreamFn  AddStream,
unsigned  ParallelCodeGenParallelismLevel,
Module M,
ModuleSummaryIndex CombinedIndex 
)

Runs a regular LTO backend.

The regular LTO backend can also act as the regular LTO phase of ThinLTO, which may need to access the combined index.

Definition at line 552 of file LTOBackend.cpp.

References llvm::CallingConv::C, codegen(), createTargetMachine(), llvm::dbgs(), initAndLookupTarget(), LLVM_DEBUG, llvm::Mod, opt, splitCodeGen(), llvm::Error::success(), and llvm::Expected< T >::takeError().

◆ createInProcessThinBackend()

ThinBackend llvm::lto::createInProcessThinBackend ( ThreadPoolStrategy  Parallelism,
lto::IndexWriteCallback  OnWrite = nullptr,
bool  ShouldEmitIndexFiles = false,
bool  ShouldEmitImportsFiles = false 
)

This ThinBackend runs the individual backend jobs in-process.

The default value means to use one job per hardware core (not hyper-thread). OnWrite is callback which receives module identifier and notifies LTO user that index file for the module (and optionally imports file) was created. ShouldEmitIndexFiles being true will write sharded ThinLTO index files to the same path as the input module, with suffix ".thinlto.bc" ShouldEmitImportsFiles is true it also writes a list of imported files to a similar path with ".imports" appended instead.

Definition at line 1779 of file LTO.cpp.

◆ createOutOfProcessThinBackend()

ThinBackend llvm::lto::createOutOfProcessThinBackend ( ThreadPoolStrategy  Parallelism,
lto::IndexWriteCallback  OnWrite,
bool  ShouldEmitIndexFiles,
bool  ShouldEmitImportsFiles,
StringRef  LinkerOutputFile,
StringRef  Distributor,
ArrayRef< StringRef DistributorArgs,
StringRef  RemoteCompiler,
ArrayRef< StringRef RemoteCompilerArgs,
bool  SaveTemps 
)

This ThinBackend generates the index shards and then runs the individual backend jobs via an external process.

It takes the same parameters as the InProcessThinBackend; however, these parameters only control the behavior when generating the index files for the modules. Additionally: LinkerOutputFile is a string that should identify this LTO invocation in the context of a wider build. It's used for naming to aid the user in identifying activity related to a specific LTO invocation. Distributor specifies the path to a process to invoke to manage the backend job execution. DistributorArgs specifies a list of arguments to be applied to the distributor. RemoteCompiler specifies the path to a Clang executable to be invoked for the backend jobs. RemoteCompilerArgs specifies a list of arguments to be applied to the backend compilations. SaveTemps is a debugging tool that prevents temporary files created by this backend from being cleaned up.

Definition at line 2529 of file LTO.cpp.

◆ createWriteIndexesThinBackend()

ThinBackend llvm::lto::createWriteIndexesThinBackend ( ThreadPoolStrategy  Parallelism,
std::string  OldPrefix,
std::string  NewPrefix,
std::string  NativeObjectPrefix,
bool  ShouldEmitImportsFiles,
raw_fd_ostream LinkedObjectsFile,
IndexWriteCallback  OnWrite 
)

This ThinBackend writes individual module indexes to files, instead of running the individual backend jobs.

This backend is for distributed builds where separate processes will invoke the real backends.

To find the path to write the index to, the backend checks if the path has a prefix of OldPrefix; if so, it replaces that prefix with NewPrefix. It then appends ".thinlto.bc" and writes the index to that path. If ShouldEmitImportsFiles is true it also writes a list of imported files to a similar path with ".imports" appended instead. LinkedObjectsFile is an output stream to write the list of object files for the final ThinLTO linking. Can be nullptr. If LinkedObjectsFile is not nullptr and NativeObjectPrefix is not empty then it replaces the prefix of the objects with NativeObjectPrefix instead of NewPrefix. OnWrite is callback which receives module identifier and notifies LTO user that index file for the module (and optionally imports file) was created.

Definition at line 1899 of file LTO.cpp.

◆ finalizeOptimizationRemarks()

Error llvm::lto::finalizeOptimizationRemarks ( std::unique_ptr< ToolOutputFile DiagOutputFile)

Definition at line 541 of file LTOBackend.cpp.

References llvm::Error::success().

Referenced by thinBackend().

◆ findThinLTOModule() [1/2]

Expected< BitcodeModule > llvm::lto::findThinLTOModule ( MemoryBufferRef  MBRef)

◆ findThinLTOModule() [2/2]

BitcodeModule * llvm::lto::findThinLTOModule ( MutableArrayRef< BitcodeModule BMs)

Returns the BitcodeModule that is ThinLTO.

Definition at line 730 of file LTOBackend.cpp.

References llvm::MutableArrayRef< T >::begin(), llvm::ArrayRef< T >::size(), and ThinLTOAssumeMerged.

Referenced by findThinLTOModule(), and thinBackend().

◆ generateModulesOrdering()

std::vector< int > llvm::lto::generateModulesOrdering ( ArrayRef< BitcodeModule * >  R)

Produces a container ordering for optimal multi-threaded processing.

Returns ordered indices to elements in the input array.

Definition at line 2211 of file LTO.cpp.

References llvm::size(), and llvm::sort().

Referenced by llvm::ThinLTOCodeGenerator::run().

◆ getThinLTODefaultCPU()

StringLiteral llvm::lto::getThinLTODefaultCPU ( const Triple TheTriple)

◆ getThinLTOOutputFile()

std::string llvm::lto::getThinLTOOutputFile ( StringRef  Path,
StringRef  OldPrefix,
StringRef  NewPrefix 
)

Given the original Path to an output file, replace any path prefix matching OldPrefix with NewPrefix.

Also, create the resulting directory if it does not yet exist.

Definition at line 1813 of file LTO.cpp.

References llvm::sys::fs::create_directories(), llvm::StringRef::empty(), llvm::errs(), llvm::sys::path::parent_path(), llvm::sys::path::replace_path_prefix(), and llvm::SmallString< InternalLen >::str().

◆ initImportList()

bool llvm::lto::initImportList ( const Module M,
const ModuleSummaryIndex CombinedIndex,
FunctionImporter::ImportMapTy ImportList 
)

Distributed ThinLTO: collect the referenced modules based on module summary and initialize ImportList.

Returns false if the operation failed.

Definition at line 756 of file LTOBackend.cpp.

References llvm::FunctionImporter::ImportMapTy::addGUID(), and ThinLTOAssumeMerged.

◆ opt()

bool llvm::lto::opt ( const Config Conf,
TargetMachine TM,
unsigned  Task,
Module Mod,
bool  IsThinLTO,
ModuleSummaryIndex ExportSummary,
const ModuleSummaryIndex ImportSummary,
const std::vector< uint8_t > &  CmdArgs 
)

◆ setupLLVMOptimizationRemarks()

Expected< std::unique_ptr< ToolOutputFile > > llvm::lto::setupLLVMOptimizationRemarks ( LLVMContext Context,
StringRef  RemarksFilename,
StringRef  RemarksPasses,
StringRef  RemarksFormat,
bool  RemarksWithHotness,
std::optional< uint64_t RemarksHotnessThreshold = 0,
int  Count = -1 
)

◆ setupStatsFile()

Expected< std::unique_ptr< ToolOutputFile > > llvm::lto::setupStatsFile ( StringRef  StatsFilename)

Setups the output file for saving statistics.

Definition at line 2192 of file LTO.cpp.

References llvm::StringRef::empty(), llvm::EnableStatistics(), llvm::errorCodeToError(), and llvm::sys::fs::OF_None.

Referenced by llvm::LTOCodeGenerator::optimize(), and llvm::lto::LTO::run().

◆ thinBackend()

Error llvm::lto::thinBackend ( const Config C,
unsigned  Task,
AddStreamFn  AddStream,
Module M,
const ModuleSummaryIndex CombinedIndex,
const FunctionImporter::ImportMapTy ImportList,
const GVSummaryMapTy DefinedGlobals,
MapVector< StringRef, BitcodeModule > *  ModuleMap,
bool  CodeGenOnly,
AddStreamFn  IRAddStream = nullptr,
const std::vector< uint8_t > &  CmdArgs = std::vector<uint8_t>() 
)

Runs a ThinLTO backend.

If ModuleMap is not nullptr, all the module files to be imported have already been mapped to memory and the corresponding BitcodeModule objects are saved in the ModuleMap. If ModuleMap is nullptr, module files will be mapped to memory on demand and at any given time during importing, only one source module will be kept open at the most. If CodeGenOnly is true, the backend will skip optimization and only perform code generation. If IRAddStream is not nullptr, it will be called just before code generation to serialize the optimized IR.

Definition at line 599 of file LTOBackend.cpp.

References assert(), codegen(), createTargetMachine(), llvm::dbgs(), llvm::PIELevel::Default, dropDeadSymbols(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::empty(), llvm::MapVector< KeyT, ValueT, MapType, VectorType >::end(), finalizeOptimizationRemarks(), llvm::MapVector< KeyT, ValueT, MapType, VectorType >::find(), findThinLTOModule(), llvm::ErrorOr< T >::getError(), llvm::MemoryBuffer::getFile(), I, llvm::FunctionImporter::importFunctions(), llvm::inconvertibleErrorCode(), initAndLookupTarget(), LLVM_DEBUG, llvm::Mod, opt, llvm::lto::Config::PostImportModuleHook, llvm::lto::Config::PostInternalizeModuleHook, llvm::lto::Config::PostPromoteModuleHook, llvm::lto::Config::PreOptModuleHook, llvm::lto::Config::RemarksFilename, llvm::lto::Config::RemarksFormat, llvm::lto::Config::RemarksHotnessThreshold, llvm::lto::Config::RemarksPasses, llvm::lto::Config::RemarksWithHotness, llvm::renameModuleForThinLTO(), llvm::cgdata::saveModuleForTwoRounds(), setupLLVMOptimizationRemarks(), llvm::Reloc::Static, llvm::Expected< T >::takeError(), ThinLTOAssumeMerged, llvm::thinLTOFinalizeInModule(), llvm::thinLTOInternalizeModule(), llvm::toString(), updateMemProfAttributes(), llvm::updatePublicTypeTestCalls(), and llvm::ModuleSummaryIndex::withWholeProgramVisibility().

◆ updateMemProfAttributes()

void llvm::lto::updateMemProfAttributes ( Module Mod,
const ModuleSummaryIndex Index 
)

Updates MemProf attributes (and metadata) based on whether the index has recorded that we are linking with allocation libraries containing the necessary APIs for downstream transformations.

Definition at line 1253 of file LTO.cpp.

References F, I, and llvm::Mod.

Referenced by thinBackend().