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
	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< LLVMRemarkFileHandle >	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 (LLVMRemarkFileHandle DiagOutputFile)
LLVM_ABI BitcodeModule *	findThinLTOModule (MutableArrayRef< BitcodeModule > BMs)
	Returns the BitcodeModule that is ThinLTO.
LLVM_ABI Expected< BitcodeModule >	findThinLTOModule (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

using llvm::lto::ImportsFilesContainer = llvm::SmallVector<std::string>

Definition at line 207 of file LTO.h.

IndexWriteCallback

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

Definition at line 205 of file LTO.h.

ThinBackendFunction

using llvm::lto::ThinBackendFunction

Initial value:

 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 270 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 553 of file LTOBackend.cpp.

References llvm::CallingConv::C, 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 1791 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 2542 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 1911 of file LTO.cpp.

finalizeOptimizationRemarks()

Error llvm::lto::finalizeOptimizationRemarks

(

LLVMRemarkFileHandle

DiagOutputFile

)

Definition at line 542 of file LTOBackend.cpp.

References llvm::LLVMRemarkFileHandle::finalize(), llvm::raw_ostream::flush(), llvm::ToolOutputFile::keep(), llvm::ToolOutputFile::os(), and llvm::Error::success().

Referenced by thinBackend().

findThinLTOModule() [1/2]

Expected< BitcodeModule > llvm::lto::findThinLTOModule

(

MemoryBufferRef

MBRef

)

Variant of the above.

Definition at line 750 of file LTOBackend.cpp.

References findThinLTOModule(), llvm::getBitcodeModuleList(), llvm::inconvertibleErrorCode(), llvm::make_error(), and llvm::Expected< T >::takeError().

findThinLTOModule() [2/2]

BitcodeModule * llvm::lto::findThinLTOModule

(

MutableArrayRef< BitcodeModule >

BMs

)

Returns the BitcodeModule that is ThinLTO.

Definition at line 738 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 2224 of file LTO.cpp.

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

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

getThinLTODefaultCPU()

StringLiteral llvm::lto::getThinLTODefaultCPU

(

const Triple &

TheTriple

)

Definition at line 1807 of file LTO.cpp.

References llvm::Triple::aarch64, llvm::Triple::aarch64_32, llvm::Triple::getArch(), llvm::Triple::isArm64e(), llvm::Triple::isOSDarwin(), llvm::Triple::x86, and llvm::Triple::x86_64.

Referenced by initTMBuilder().

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 1825 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 764 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 )

Runs middle-end LTO optimizations on Mod.

Definition at line 364 of file LTOBackend.cpp.

References llvm::dbgs(), EmbedBitcode, llvm::embedBitcodeInModule(), EmbedPostMergePreOptimized, isEmptyModule(), LLVM_DEBUG, llvm::Mod, llvm::lto::Config::OptLevel, llvm::lto::Config::PostOptModuleHook, and runNewPMPasses().

Referenced by backend(), and thinBackend().

setupLLVMOptimizationRemarks()

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

Setup optimization remarks.

Definition at line 2180 of file LTO.cpp.

References llvm::Count, llvm::RemarksFilename, llvm::RemarksFormat, llvm::RemarksHotnessThreshold, llvm::RemarksPasses, llvm::RemarksWithHotness, llvm::setupLLVMOptimizationRemarks(), and llvm::utostr().

Referenced by llvm::LTOCodeGenerator::optimize(), llvm::ThinLTOCodeGenerator::run(), and thinBackend().

setupStatsFile()

Expected< std::unique_ptr< ToolOutputFile > > llvm::lto::setupStatsFile

(

StringRef

StatsFilename

)

Setups the output file for saving statistics.

Definition at line 2205 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 602 of file LTOBackend.cpp.

References assert(), 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::make_error(), 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 1259 of file LTO.cpp.

References llvm::dyn_cast(), F, I, and llvm::Mod.

Referenced by thinBackend().