LLVM  16.0.0git
Macros | Functions | Variables
FunctionImport.cpp File Reference
#include "llvm/Transforms/IPO/FunctionImport.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Bitcode/BitcodeReader.h"
#include "llvm/IR/AutoUpgrade.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/GlobalAlias.h"
#include "llvm/IR/GlobalObject.h"
#include "llvm/IR/GlobalValue.h"
#include "llvm/IR/GlobalVariable.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Module.h"
#include "llvm/IR/ModuleSummaryIndex.h"
#include "llvm/IRReader/IRReader.h"
#include "llvm/InitializePasses.h"
#include "llvm/Linker/IRMover.h"
#include "llvm/Pass.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/Error.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/FileSystem.h"
#include "llvm/Support/SourceMgr.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Transforms/IPO/Internalize.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Transforms/Utils/FunctionImportUtils.h"
#include "llvm/Transforms/Utils/ValueMapper.h"
#include <cassert>
#include <memory>
#include <set>
#include <string>
#include <system_error>
#include <tuple>
#include <utility>
Include dependency graph for FunctionImport.cpp:

Go to the source code of this file.

Macros

#define DEBUG_TYPE   "function-import"
 

Functions

 STATISTIC (NumImportedFunctionsThinLink, "Number of functions thin link decided to import")
 
 STATISTIC (NumImportedHotFunctionsThinLink, "Number of hot functions thin link decided to import")
 
 STATISTIC (NumImportedCriticalFunctionsThinLink, "Number of critical functions thin link decided to import")
 
 STATISTIC (NumImportedGlobalVarsThinLink, "Number of global variables thin link decided to import")
 
 STATISTIC (NumImportedFunctions, "Number of functions imported in backend")
 
 STATISTIC (NumImportedGlobalVars, "Number of global variables imported in backend")
 
 STATISTIC (NumImportedModules, "Number of modules imported from")
 
 STATISTIC (NumDeadSymbols, "Number of dead stripped symbols in index")
 
 STATISTIC (NumLiveSymbols, "Number of live symbols in index")
 
static std::unique_ptr< Module > loadFile (const std::string &FileName, LLVMContext &Context)
 
static const GlobalValueSummary * selectCallee (const ModuleSummaryIndex &Index, ArrayRef< std::unique_ptr< GlobalValueSummary >> CalleeSummaryList, unsigned Threshold, StringRef CallerModulePath, FunctionImporter::ImportFailureReason &Reason, GlobalValue::GUID GUID)
 Given a list of possible callee implementation for a call site, select one that fits the Threshold. More...
 
static bool shouldImportGlobal (const ValueInfo &VI, const GVSummaryMapTy &DefinedGVSummaries)
 
static void computeImportForReferencedGlobals (const GlobalValueSummary &Summary, const ModuleSummaryIndex &Index, const GVSummaryMapTy &DefinedGVSummaries, SmallVectorImpl< EdgeInfo > &Worklist, FunctionImporter::ImportMapTy &ImportList, StringMap< FunctionImporter::ExportSetTy > *ExportLists)
 
static const char * getFailureName (FunctionImporter::ImportFailureReason Reason)
 
static void computeImportForFunction (const FunctionSummary &Summary, const ModuleSummaryIndex &Index, const unsigned Threshold, const GVSummaryMapTy &DefinedGVSummaries, SmallVectorImpl< EdgeInfo > &Worklist, FunctionImporter::ImportMapTy &ImportList, StringMap< FunctionImporter::ExportSetTy > *ExportLists, FunctionImporter::ImportThresholdsTy &ImportThresholds)
 Compute the list of functions to import for a given caller. More...
 
static void ComputeImportForModule (const GVSummaryMapTy &DefinedGVSummaries, const ModuleSummaryIndex &Index, StringRef ModName, FunctionImporter::ImportMapTy &ImportList, StringMap< FunctionImporter::ExportSetTy > *ExportLists=nullptr)
 Given the list of globals defined in a module, compute the list of imports as well as the list of "exports", i.e. More...
 
static bool isGlobalVarSummary (const ModuleSummaryIndex &Index, ValueInfo VI)
 
static bool isGlobalVarSummary (const ModuleSummaryIndex &Index, GlobalValue::GUID G)
 
template<class T >
static unsigned numGlobalVarSummaries (const ModuleSummaryIndex &Index, T &Cont)
 
static bool checkVariableImport (const ModuleSummaryIndex &Index, StringMap< FunctionImporter::ImportMapTy > &ImportLists, StringMap< FunctionImporter::ExportSetTy > &ExportLists)
 
static void dumpImportListForModule (const ModuleSummaryIndex &Index, StringRef ModulePath, FunctionImporter::ImportMapTy &ImportList)
 
void updateValueInfoForIndirectCalls (ModuleSummaryIndex &Index, FunctionSummary *FS)
 
static Function * replaceAliasWithAliasee (Module *SrcModule, GlobalAlias *GA)
 Make alias a clone of its aliasee. More...
 
static void internalizeGVsAfterImport (Module &M)
 
static bool doImportingForModule (Module &M)
 

Variables

static cl::opt< unsigned > ImportInstrLimit ("import-instr-limit", cl::init(100), cl::Hidden, cl::value_desc("N"), cl::desc("Only import functions with less than N instructions"))
 Limit on instruction count of imported functions. More...
 
static cl::opt< int > ImportCutoff ("import-cutoff", cl::init(-1), cl::Hidden, cl::value_desc("N"), cl::desc("Only import first N functions if N>=0 (default -1)"))
 
static cl::opt< bool > ForceImportAll ("force-import-all", cl::init(false), cl::Hidden, cl::desc("Import functions with noinline attribute"))
 
static cl::opt< float > ImportInstrFactor ("import-instr-evolution-factor", cl::init(0.7), cl::Hidden, cl::value_desc("x"), cl::desc("As we import functions, multiply the " "`import-instr-limit` threshold by this factor " "before processing newly imported functions"))
 
static cl::opt< float > ImportHotInstrFactor ("import-hot-evolution-factor", cl::init(1.0), cl::Hidden, cl::value_desc("x"), cl::desc("As we import functions called from hot callsite, multiply the " "`import-instr-limit` threshold by this factor " "before processing newly imported functions"))
 
static cl::opt< float > ImportHotMultiplier ("import-hot-multiplier", cl::init(10.0), cl::Hidden, cl::value_desc("x"), cl::desc("Multiply the `import-instr-limit` threshold for hot callsites"))
 
static cl::opt< float > ImportCriticalMultiplier ("import-critical-multiplier", cl::init(100.0), cl::Hidden, cl::value_desc("x"), cl::desc("Multiply the `import-instr-limit` threshold for critical callsites"))
 
static cl::opt< float > ImportColdMultiplier ("import-cold-multiplier", cl::init(0), cl::Hidden, cl::value_desc("N"), cl::desc("Multiply the `import-instr-limit` threshold for cold callsites"))
 
static cl::opt< bool > PrintImports ("print-imports", cl::init(false), cl::Hidden, cl::desc("Print imported functions"))
 
static cl::opt< bool > PrintImportFailures ("print-import-failures", cl::init(false), cl::Hidden, cl::desc("Print information for functions rejected for importing"))
 
static cl::opt< bool > ComputeDead ("compute-dead", cl::init(true), cl::Hidden, cl::desc("Compute dead symbols"))
 
static cl::opt< bool > EnableImportMetadata ("enable-import-metadata", cl::init(false), cl::Hidden, cl::desc("Enable import metadata like 'thinlto_src_module'"))
 
static cl::opt< std::string > SummaryFile ("summary-file", cl::desc("The summary file to use for function importing."))
 Summary file to use for function importing when using -function-import from the command line. More...
 
static cl::opt< bool > ImportAllIndex ("import-all-index", cl::desc("Import all external functions in index."))
 Used when testing importing from distributed indexes via opt. More...
 

Macro Definition Documentation

◆ DEBUG_TYPE

#define DEBUG_TYPE   "function-import"

Definition at line 59 of file FunctionImport.cpp.

Function Documentation

◆ checkVariableImport()

static bool checkVariableImport ( const ModuleSummaryIndex &  Index,
StringMap< FunctionImporter::ImportMapTy > &  ImportLists,
StringMap< FunctionImporter::ExportSetTy > &  ExportLists 
)
static

Definition at line 621 of file FunctionImport.cpp.

References llvm::detail::DenseSetImpl< ValueT, DenseMap< ValueT, detail::DenseSetEmpty, DenseMapInfo< ValueT >, detail::DenseSetPair< ValueT > >, DenseMapInfo< ValueT > >::count(), llvm::detail::DenseSetImpl< ValueT, DenseMap< ValueT, detail::DenseSetEmpty, DenseMapInfo< ValueT >, detail::DenseSetPair< ValueT > >, DenseMapInfo< ValueT > >::insert(), and VI.

Referenced by llvm::ComputeCrossModuleImport().

◆ computeImportForFunction()

static void computeImportForFunction ( const FunctionSummary &  Summary,
const ModuleSummaryIndex &  Index,
const unsigned  Threshold,
const GVSummaryMapTy &  DefinedGVSummaries,
SmallVectorImpl< EdgeInfo > &  Worklist,
FunctionImporter::ImportMapTy &  ImportList,
StringMap< FunctionImporter::ExportSetTy > *  ExportLists,
FunctionImporter::ImportThresholdsTy &  ImportThresholds 
)
static

Compute the list of functions to import for a given caller.

Mark these imported functions and the symbols they reference in their source module as exported from their source module.

Definition at line 348 of file FunctionImport.cpp.

References llvm::FunctionSummary::FFlags::AlwaysInline, assert(), llvm::FunctionSummary::calls(), llvm::CalleeInfo::Cold, computeImportForReferencedGlobals(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::count(), llvm::CalleeInfo::Critical, llvm::dbgs(), llvm::SmallVectorImpl< T >::emplace_back(), llvm::errs(), llvm::FunctionSummary::fflags(), ForceImportAll, getFailureName(), llvm::CalleeInfo::Hot, ImportColdMultiplier, ImportCriticalMultiplier, ImportCutoff, ImportHotInstrFactor, ImportHotMultiplier, ImportInstrFactor, llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::insert(), llvm::StringMap< ValueTy, AllocatorTy >::insert(), llvm::FunctionSummary::instCount(), IT, LLVM_DEBUG, llvm::logAllUnhandledErrors(), llvm::make_error_code(), llvm::max(), llvm::GlobalValueSummary::modulePath(), move, llvm::AMDGPU::SendMsg::Msg, llvm::not_supported, PrintImportFailures, selectCallee(), and VI.

Referenced by ComputeImportForModule().

◆ ComputeImportForModule()

static void ComputeImportForModule ( const GVSummaryMapTy &  DefinedGVSummaries,
const ModuleSummaryIndex &  Index,
StringRef  ModName,
FunctionImporter::ImportMapTy &  ImportList,
StringMap< FunctionImporter::ExportSetTy > *  ExportLists = nullptr 
)
static

Given the list of globals defined in a module, compute the list of imports as well as the list of "exports", i.e.

the list of symbols referenced from another module (that may require promotion).

Definition at line 521 of file FunctionImport.cpp.

References assert(), computeImportForFunction(), computeImportForReferencedGlobals(), llvm::dbgs(), llvm::X86AS::FS, getFailureName(), llvm::getHotnessName(), I, ImportInstrLimit, int, LLVM_DEBUG, llvm::SmallVectorImpl< T >::pop_back_val(), PrintImportFailures, and VI.

Referenced by llvm::ComputeCrossModuleImport(), and llvm::ComputeCrossModuleImportForModule().

◆ computeImportForReferencedGlobals()

static void computeImportForReferencedGlobals ( const GlobalValueSummary &  Summary,
const ModuleSummaryIndex &  Index,
const GVSummaryMapTy &  DefinedGVSummaries,
SmallVectorImpl< EdgeInfo > &  Worklist,
FunctionImporter::ImportMapTy &  ImportList,
StringMap< FunctionImporter::ExportSetTy > *  ExportLists 
)
static

Definition at line 271 of file FunctionImport.cpp.

References llvm::dbgs(), llvm::SmallVectorImpl< T >::emplace_back(), llvm::StringMap< ValueTy, AllocatorTy >::insert(), llvm::GlobalValue::isLocalLinkage(), LLVM_DEBUG, llvm::GlobalValueSummary::modulePath(), llvm::GlobalValueSummary::refs(), shouldImportGlobal(), and VI.

Referenced by computeImportForFunction(), and ComputeImportForModule().

◆ doImportingForModule()

static bool doImportingForModule ( Module &  M)
static

Definition at line 1363 of file FunctionImport.cpp.

References llvm::ComputeCrossModuleImportForModule(), llvm::ComputeCrossModuleImportForModuleFromIndex(), llvm::errs(), llvm::GlobalValue::ExternalLinkage, llvm::getModuleSummaryIndexForFile(), I, ImportAllIndex, llvm::FunctionImporter::importFunctions(), llvm::GlobalValue::isLocalLinkage(), loadFile(), llvm::logAllUnhandledErrors(), M, move, llvm::renameModuleForThinLTO(), llvm::report_fatal_error(), S, SummaryFile, and llvm::Expected< T >::takeError().

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

◆ dumpImportListForModule()

static void dumpImportListForModule ( const ModuleSummaryIndex &  Index,
StringRef  ModulePath,
FunctionImporter::ImportMapTy &  ImportList 
)
static

Definition at line 744 of file FunctionImport.cpp.

References llvm::dbgs(), LLVM_DEBUG, numGlobalVarSummaries(), and llvm::StringMapImpl::size().

Referenced by llvm::ComputeCrossModuleImportForModule(), and llvm::ComputeCrossModuleImportForModuleFromIndex().

◆ getFailureName()

static const char* getFailureName ( FunctionImporter::ImportFailureReason  Reason)
static

Definition at line 323 of file FunctionImport.cpp.

References llvm::lltok::GlobalVar, llvm_unreachable, and llvm::None.

Referenced by computeImportForFunction(), and ComputeImportForModule().

◆ internalizeGVsAfterImport()

static void internalizeGVsAfterImport ( Module &  M)
static

Definition at line 1208 of file FunctionImport.cpp.

References llvm::GlobalValue::DefaultVisibility, llvm::GlobalValue::InternalLinkage, and M.

◆ isGlobalVarSummary() [1/2]

static bool isGlobalVarSummary ( const ModuleSummaryIndex &  Index,
GlobalValue::GUID  G 
)
static

Definition at line 601 of file FunctionImport.cpp.

References G, isGlobalVarSummary(), and VI.

◆ isGlobalVarSummary() [2/2]

static bool isGlobalVarSummary ( const ModuleSummaryIndex &  Index,
ValueInfo  VI 
)
static

Definition at line 594 of file FunctionImport.cpp.

References false, llvm::GlobalValueSummary::GlobalVarKind, and VI.

Referenced by isGlobalVarSummary(), and numGlobalVarSummaries().

◆ loadFile()

static std::unique_ptr<Module> loadFile ( const std::string &  FileName,
LLVMContext &  Context 
)
static

Definition at line 145 of file FunctionImport.cpp.

Referenced by doImportingForModule().

◆ numGlobalVarSummaries()

template<class T >
static unsigned numGlobalVarSummaries ( const ModuleSummaryIndex &  Index,
T &  Cont 
)
static

Definition at line 609 of file FunctionImport.cpp.

References isGlobalVarSummary().

Referenced by llvm::ComputeCrossModuleImport(), and dumpImportListForModule().

◆ replaceAliasWithAliasee()

static Function* replaceAliasWithAliasee ( Module *  SrcModule,
GlobalAlias *  GA 
)
static

Make alias a clone of its aliasee.

Definition at line 1192 of file FunctionImport.cpp.

References llvm::CloneFunction(), llvm::GlobalAlias::getAliaseeObject(), llvm::ConstantExpr::getBitCast(), llvm::GlobalValue::getLinkage(), llvm::GlobalValue::getType(), llvm::GlobalValue::getVisibility(), llvm::Value::replaceAllUsesWith(), llvm::GlobalValue::setLinkage(), llvm::GlobalValue::setVisibility(), and llvm::Value::takeName().

◆ selectCallee()

static const GlobalValueSummary* selectCallee ( const ModuleSummaryIndex &  Index,
ArrayRef< std::unique_ptr< GlobalValueSummary >>  CalleeSummaryList,
unsigned  Threshold,
StringRef  CallerModulePath,
FunctionImporter::ImportFailureReason &  Reason,
GlobalValue::GUID  GUID 
)
static

Given a list of possible callee implementation for a call site, select one that fits the Threshold.

FIXME: select "best" instead of first that fits. But what is "best"?

  • The smallest: more likely to be inlined.
  • The one with the least outgoing edges (already well optimized).
  • One from a module already being imported from in order to reduce the number of source modules parsed/linked.
  • One that has PGO data attached.
  • [insert you fancy metric here]

Definition at line 173 of file FunctionImport.cpp.

References llvm::find_if(), ForceImportAll, if(), llvm::GlobalValue::isInterposableLinkage(), llvm::GlobalValue::isLocalLinkage(), and llvm::None.

Referenced by computeImportForFunction().

◆ shouldImportGlobal()

static bool shouldImportGlobal ( const ValueInfo &  VI,
const GVSummaryMapTy &  DefinedGVSummaries 
)
static

Definition at line 248 of file FunctionImport.cpp.

References llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::end(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::find(), llvm::GlobalValue::isInterposableLinkage(), and VI.

Referenced by computeImportForReferencedGlobals().

◆ STATISTIC() [1/9]

STATISTIC ( NumDeadSymbols  ,
"Number of dead stripped symbols in index"   
)

◆ STATISTIC() [2/9]

STATISTIC ( NumImportedCriticalFunctionsThinLink  ,
"Number of critical functions thin link decided to import"   
)

◆ STATISTIC() [3/9]

STATISTIC ( NumImportedFunctions  ,
"Number of functions imported in backend"   
)

◆ STATISTIC() [4/9]

STATISTIC ( NumImportedFunctionsThinLink  ,
"Number of functions thin link decided to import"   
)

◆ STATISTIC() [5/9]

STATISTIC ( NumImportedGlobalVars  ,
"Number of global variables imported in backend"   
)

◆ STATISTIC() [6/9]

STATISTIC ( NumImportedGlobalVarsThinLink  ,
"Number of global variables thin link decided to import"   
)

◆ STATISTIC() [7/9]

STATISTIC ( NumImportedHotFunctionsThinLink  ,
"Number of hot functions thin link decided to import"   
)

◆ STATISTIC() [8/9]

STATISTIC ( NumImportedModules  ,
"Number of modules imported from"   
)

◆ STATISTIC() [9/9]

STATISTIC ( NumLiveSymbols  ,
"Number of live symbols in index"   
)

◆ updateValueInfoForIndirectCalls()

void updateValueInfoForIndirectCalls ( ModuleSummaryIndex &  Index,
FunctionSummary *  FS 
)

Definition at line 808 of file FunctionImport.cpp.

References llvm::any_of(), llvm::X86AS::FS, and VI.

Variable Documentation

◆ ComputeDead

cl::opt<bool> ComputeDead("compute-dead", cl::init(true), cl::Hidden, cl::desc("Compute dead symbols"))
static

Referenced by llvm::computeDeadSymbolsAndUpdateIndirectCalls().

◆ EnableImportMetadata

cl::opt<bool> EnableImportMetadata("enable-import-metadata", cl::init(false), cl::Hidden, cl::desc("Enable import metadata like 'thinlto_src_module'"))
static

◆ ForceImportAll

cl::opt<bool> ForceImportAll("force-import-all", cl::init(false), cl::Hidden, cl::desc("Import functions with noinline attribute"))
static

Referenced by computeImportForFunction(), and selectCallee().

◆ ImportAllIndex

cl::opt<bool> ImportAllIndex("import-all-index", cl::desc("Import all external functions in index."))
static

Used when testing importing from distributed indexes via opt.

Referenced by doImportingForModule().

◆ ImportColdMultiplier

cl::opt<float> ImportColdMultiplier("import-cold-multiplier", cl::init(0), cl::Hidden, cl::value_desc("N"), cl::desc("Multiply the `import-instr-limit` threshold for cold callsites"))
static

Referenced by computeImportForFunction().

◆ ImportCriticalMultiplier

cl::opt<float> ImportCriticalMultiplier("import-critical-multiplier", cl::init(100.0), cl::Hidden, cl::value_desc("x"), cl::desc( "Multiply the `import-instr-limit` threshold for critical callsites"))
static

Referenced by computeImportForFunction().

◆ ImportCutoff

cl::opt<int> ImportCutoff("import-cutoff", cl::init(-1), cl::Hidden, cl::value_desc("N"), cl::desc("Only import first N functions if N>=0 (default -1)"))
static

Referenced by computeImportForFunction().

◆ ImportHotInstrFactor

cl::opt<float> ImportHotInstrFactor("import-hot-evolution-factor", cl::init(1.0), cl::Hidden, cl::value_desc("x"), cl::desc("As we import functions called from hot callsite, multiply the " "`import-instr-limit` threshold by this factor " "before processing newly imported functions"))
static

Referenced by computeImportForFunction().

◆ ImportHotMultiplier

cl::opt<float> ImportHotMultiplier("import-hot-multiplier", cl::init(10.0), cl::Hidden, cl::value_desc("x"), cl::desc("Multiply the `import-instr-limit` threshold for hot callsites"))
static

Referenced by computeImportForFunction().

◆ ImportInstrFactor

cl::opt<float> ImportInstrFactor("import-instr-evolution-factor", cl::init(0.7), cl::Hidden, cl::value_desc("x"), cl::desc("As we import functions, multiply the " "`import-instr-limit` threshold by this factor " "before processing newly imported functions"))
static

Referenced by computeImportForFunction().

◆ ImportInstrLimit

cl::opt<unsigned> ImportInstrLimit("import-instr-limit", cl::init(100), cl::Hidden, cl::value_desc("N"), cl::desc("Only import functions with less than N instructions"))
static

Limit on instruction count of imported functions.

Referenced by ComputeImportForModule().

◆ PrintImportFailures

cl::opt<bool> PrintImportFailures("print-import-failures", cl::init(false), cl::Hidden, cl::desc("Print information for functions rejected for importing"))
static

Referenced by computeImportForFunction(), and ComputeImportForModule().

◆ PrintImports

cl::opt<bool> PrintImports("print-imports", cl::init(false), cl::Hidden, cl::desc("Print imported functions"))
static

◆ SummaryFile

cl::opt<std::string> SummaryFile("summary-file", cl::desc("The summary file to use for function importing."))
static

Summary file to use for function importing when using -function-import from the command line.

Referenced by doImportingForModule().

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