+++ /dev/null
-//===-lto.cpp - LLVM Link Time Optimizer ----------------------------------===//
-//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the Link Time Optimization library. This library is
-// intended to be used by linker to optimize code at link time.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Module.h"
-#include "llvm/PassManager.h"
-#include "llvm/Linker.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/ModuleProvider.h"
-#include "llvm/Bitcode/ReaderWriter.h"
-#include "llvm/Support/CommandLine.h"
-#include "llvm/Support/FileUtilities.h"
-#include "llvm/Support/SystemUtils.h"
-#include "llvm/Support/Mangler.h"
-#include "llvm/Support/MemoryBuffer.h"
-#include "llvm/System/Program.h"
-#include "llvm/System/Signals.h"
-#include "llvm/Analysis/Passes.h"
-#include "llvm/Analysis/LoopPass.h"
-#include "llvm/Analysis/Verifier.h"
-#include "llvm/CodeGen/FileWriters.h"
-#include "llvm/Target/SubtargetFeature.h"
-#include "llvm/Target/TargetOptions.h"
-#include "llvm/Target/TargetData.h"
-#include "llvm/Target/TargetMachine.h"
-#include "llvm/Target/TargetMachineRegistry.h"
-#include "llvm/Target/TargetAsmInfo.h"
-#include "llvm/Transforms/IPO.h"
-#include "llvm/Transforms/Scalar.h"
-#include "llvm/Analysis/LoadValueNumbering.h"
-#include "llvm/Support/MathExtras.h"
-#include "llvm/LinkTimeOptimizer.h"
-#include <fstream>
-#include <ostream>
-using namespace llvm;
-
-extern "C"
-llvm::LinkTimeOptimizer *createLLVMOptimizer(unsigned VERSION)
-{
- // Linker records LLVM_LTO_VERSION based on llvm optimizer available
- // during linker build. Match linker's recorded LTO VERSION number
- // with installed llvm optimizer version. If these numbers do not match
- // then linker may not be able to use llvm optimizer dynamically.
- if (VERSION != LLVM_LTO_VERSION)
- return NULL;
-
- llvm::LTO *l = new llvm::LTO();
- return l;
-}
-
-/// If symbol is not used then make it internal and let optimizer takes
-/// care of it.
-void LLVMSymbol::mayBeNotUsed() {
- gv->setLinkage(GlobalValue::InternalLinkage);
-}
-
-// Map LLVM LinkageType to LTO LinkageType
-static LTOLinkageTypes
-getLTOLinkageType(GlobalValue *v)
-{
- LTOLinkageTypes lt;
- if (v->hasExternalLinkage())
- lt = LTOExternalLinkage;
- else if (v->hasLinkOnceLinkage())
- lt = LTOLinkOnceLinkage;
- else if (v->hasWeakLinkage())
- lt = LTOWeakLinkage;
- else if (v->hasCommonLinkage())
- lt = LTOCommonLinkage;
- else
- // Otherwise it is internal linkage for link time optimizer
- lt = LTOInternalLinkage;
- return lt;
-}
-
-// MAP LLVM VisibilityType to LTO VisibilityType
-static LTOVisibilityTypes
-getLTOVisibilityType(GlobalValue *v)
-{
- LTOVisibilityTypes vis;
- if (v->hasHiddenVisibility())
- vis = LTOHiddenVisibility;
- else if (v->hasProtectedVisibility())
- vis = LTOProtectedVisibility;
- else
- vis = LTODefaultVisibility;
- return vis;
-}
-
-// Find exeternal symbols referenced by VALUE. This is a recursive function.
-static void
-findExternalRefs(Value *value, std::set<std::string> &references,
- Mangler &mangler) {
-
- if (GlobalValue *gv = dyn_cast<GlobalValue>(value)) {
- LTOLinkageTypes lt = getLTOLinkageType(gv);
- if (lt != LTOInternalLinkage && strncmp (gv->getName().c_str(), "llvm.", 5))
- references.insert(mangler.getValueName(gv));
- }
-
- // GlobalValue, even with InternalLinkage type, may have operands with
- // ExternalLinkage type. Do not ignore these operands.
- if (Constant *c = dyn_cast<Constant>(value))
- // Handle ConstantExpr, ConstantStruct, ConstantArry etc..
- for (unsigned i = 0, e = c->getNumOperands(); i != e; ++i)
- findExternalRefs(c->getOperand(i), references, mangler);
-}
-
-/// If Module with InputFilename is available then remove it from allModules
-/// and call delete on it.
-void
-LTO::removeModule (const std::string &InputFilename)
-{
- NameToModuleMap::iterator pos = allModules.find(InputFilename.c_str());
- if (pos == allModules.end())
- return;
-
- Module *m = pos->second;
- allModules.erase(pos);
- delete m;
-}
-
-/// InputFilename is a LLVM bitcode file. If Module with InputFilename is
-/// available then return it. Otherwise parseInputFilename.
-Module *
-LTO::getModule(const std::string &InputFilename)
-{
- Module *m = NULL;
-
- NameToModuleMap::iterator pos = allModules.find(InputFilename.c_str());
- if (pos != allModules.end())
- m = allModules[InputFilename.c_str()];
- else {
- if (MemoryBuffer *Buffer
- = MemoryBuffer::getFile(&InputFilename[0], InputFilename.size())) {
- m = ParseBitcodeFile(Buffer);
- delete Buffer;
- }
- allModules[InputFilename.c_str()] = m;
- }
- return m;
-}
-
-/// InputFilename is a LLVM bitcode file. Reade this bitcode file and
-/// set corresponding target triplet string.
-void
-LTO::getTargetTriple(const std::string &InputFilename,
- std::string &targetTriple)
-{
- Module *m = getModule(InputFilename);
- if (m)
- targetTriple = m->getTargetTriple();
-}
-
-/// InputFilename is a LLVM bitcode file. Read it using bitcode reader.
-/// Collect global functions and symbol names in symbols vector.
-/// Collect external references in references vector.
-/// Return LTO_READ_SUCCESS if there is no error.
-enum LTOStatus
-LTO::readLLVMObjectFile(const std::string &InputFilename,
- NameToSymbolMap &symbols,
- std::set<std::string> &references)
-{
- Module *m = getModule(InputFilename);
- if (!m)
- return LTO_READ_FAILURE;
-
- // Collect Target info
- getTarget(m);
-
- if (!Target)
- return LTO_READ_FAILURE;
-
- // Use mangler to add GlobalPrefix to names to match linker names.
- // FIXME : Instead of hard coding "-" use GlobalPrefix.
- Mangler mangler(*m, Target->getTargetAsmInfo()->getGlobalPrefix());
- modules.push_back(m);
-
- for (Module::iterator f = m->begin(), e = m->end(); f != e; ++f) {
- LTOLinkageTypes lt = getLTOLinkageType(f);
- LTOVisibilityTypes vis = getLTOVisibilityType(f);
- if (!f->isDeclaration() && lt != LTOInternalLinkage
- && strncmp (f->getName().c_str(), "llvm.", 5)) {
- int alignment = ( 16 > f->getAlignment() ? 16 : f->getAlignment());
- LLVMSymbol *newSymbol = new LLVMSymbol(lt, vis, f, f->getName(),
- mangler.getValueName(f),
- Log2_32(alignment));
- symbols[newSymbol->getMangledName()] = newSymbol;
- allSymbols[newSymbol->getMangledName()] = newSymbol;
- }
-
- // Collect external symbols referenced by this function.
- for (Function::iterator b = f->begin(), fe = f->end(); b != fe; ++b)
- for (BasicBlock::iterator i = b->begin(), be = b->end();
- i != be; ++i) {
- for (unsigned count = 0, total = i->getNumOperands();
- count != total; ++count)
- findExternalRefs(i->getOperand(count), references, mangler);
- }
- }
-
- for (Module::global_iterator v = m->global_begin(), e = m->global_end();
- v != e; ++v) {
- LTOLinkageTypes lt = getLTOLinkageType(v);
- LTOVisibilityTypes vis = getLTOVisibilityType(v);
- if (!v->isDeclaration() && lt != LTOInternalLinkage
- && strncmp (v->getName().c_str(), "llvm.", 5)) {
- const TargetData *TD = Target->getTargetData();
- LLVMSymbol *newSymbol = new LLVMSymbol(lt, vis, v, v->getName(),
- mangler.getValueName(v),
- TD->getPreferredAlignmentLog(v));
- symbols[newSymbol->getMangledName()] = newSymbol;
- allSymbols[newSymbol->getMangledName()] = newSymbol;
-
- for (unsigned count = 0, total = v->getNumOperands();
- count != total; ++count)
- findExternalRefs(v->getOperand(count), references, mangler);
-
- }
- }
-
- return LTO_READ_SUCCESS;
-}
-
-/// Get TargetMachine.
-/// Use module M to find appropriate Target.
-void
-LTO::getTarget (Module *M) {
-
- if (Target)
- return;
-
- std::string Err;
- const TargetMachineRegistry::entry* March =
- TargetMachineRegistry::getClosestStaticTargetForModule(*M, Err);
-
- if (March == 0)
- return;
-
- // Create target
- SubtargetFeatures Features;
- std::string FeatureStr;
- std::string TargetTriple = M->getTargetTriple();
-
- if (strncmp(TargetTriple.c_str(), "powerpc-apple-", 14) == 0)
- Features.AddFeature("altivec", true);
- else if (strncmp(TargetTriple.c_str(), "powerpc64-apple-", 16) == 0) {
- Features.AddFeature("64bit", true);
- Features.AddFeature("altivec", true);
- }
-
- FeatureStr = Features.getString();
- Target = March->CtorFn(*M, FeatureStr);
-}
-
-/// Optimize module M using various IPO passes. Use exportList to
-/// internalize selected symbols. Target platform is selected
-/// based on information available to module M. No new target
-/// features are selected.
-enum LTOStatus
-LTO::optimize(Module *M, std::ostream &Out,
- std::vector<const char *> &exportList)
-{
- // Instantiate the pass manager to organize the passes.
- PassManager Passes;
-
- // Collect Target info
- getTarget(M);
-
- if (!Target)
- return LTO_NO_TARGET;
-
- // If target supports exception handling then enable it now.
- if (Target->getTargetAsmInfo()->doesSupportExceptionHandling())
- ExceptionHandling = true;
-
- // Start off with a verification pass.
- Passes.add(createVerifierPass());
-
- // Add an appropriate TargetData instance for this module...
- Passes.add(new TargetData(*Target->getTargetData()));
-
- // Internalize symbols if export list is nonemty
- if (!exportList.empty())
- Passes.add(createInternalizePass(exportList));
-
- // Now that we internalized some globals, see if we can hack on them!
- Passes.add(createGlobalOptimizerPass());
-
- // Linking modules together can lead to duplicated global constants, only
- // keep one copy of each constant...
- Passes.add(createConstantMergePass());
-
- // If the -s command line option was specified, strip the symbols out of the
- // resulting program to make it smaller. -s is a GLD option that we are
- // supporting.
- Passes.add(createStripSymbolsPass());
-
- // Propagate constants at call sites into the functions they call.
- Passes.add(createIPConstantPropagationPass());
-
- // Remove unused arguments from functions...
- Passes.add(createDeadArgEliminationPass());
-
- Passes.add(createFunctionInliningPass()); // Inline small functions
-
- Passes.add(createPruneEHPass()); // Remove dead EH info
-
- Passes.add(createGlobalDCEPass()); // Remove dead functions
-
- // If we didn't decide to inline a function, check to see if we can
- // transform it to pass arguments by value instead of by reference.
- Passes.add(createArgumentPromotionPass());
-
- // The IPO passes may leave cruft around. Clean up after them.
- Passes.add(createInstructionCombiningPass());
-
- Passes.add(createScalarReplAggregatesPass()); // Break up allocas
-
- // Run a few AA driven optimizations here and now, to cleanup the code.
- Passes.add(createGlobalsModRefPass()); // IP alias analysis
-
- Passes.add(createLICMPass()); // Hoist loop invariants
- Passes.add(createGVNPass()); // Remove common subexprs
- Passed.add(createMemCpyOptPass()); // Remove dead memcpy's
- Passes.add(createDeadStoreEliminationPass()); // Nuke dead stores
-
- // Cleanup and simplify the code after the scalar optimizations.
- Passes.add(createInstructionCombiningPass());
-
- // Delete basic blocks, which optimization passes may have killed...
- Passes.add(createCFGSimplificationPass());
-
- // Now that we have optimized the program, discard unreachable functions...
- Passes.add(createGlobalDCEPass());
-
- // Make sure everything is still good.
- Passes.add(createVerifierPass());
-
- FunctionPassManager *CodeGenPasses =
- new FunctionPassManager(new ExistingModuleProvider(M));
-
- CodeGenPasses->add(new TargetData(*Target->getTargetData()));
-
- MachineCodeEmitter *MCE = 0;
-
- switch (Target->addPassesToEmitFile(*CodeGenPasses, Out,
- TargetMachine::AssemblyFile, true)) {
- default:
- case FileModel::Error:
- return LTO_WRITE_FAILURE;
- case FileModel::AsmFile:
- break;
- case FileModel::MachOFile:
- MCE = AddMachOWriter(*CodeGenPasses, Out, *Target);
- break;
- case FileModel::ElfFile:
- MCE = AddELFWriter(*CodeGenPasses, Out, *Target);
- break;
- }
-
- if (Target->addPassesToEmitFileFinish(*CodeGenPasses, MCE, true))
- return LTO_WRITE_FAILURE;
-
- // Run our queue of passes all at once now, efficiently.
- Passes.run(*M);
-
- // Run the code generator, if present.
- CodeGenPasses->doInitialization();
- for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I) {
- if (!I->isDeclaration())
- CodeGenPasses->run(*I);
- }
- CodeGenPasses->doFinalization();
-
- return LTO_OPT_SUCCESS;
-}
-
-///Link all modules together and optimize them using IPO. Generate
-/// native object file using OutputFilename
-/// Return appropriate LTOStatus.
-enum LTOStatus
-LTO::optimizeModules(const std::string &OutputFilename,
- std::vector<const char *> &exportList,
- std::string &targetTriple,
- bool saveTemps, const char *FinalOutputFilename)
-{
- if (modules.empty())
- return LTO_NO_WORK;
-
- std::ios::openmode io_mode =
- std::ios::out | std::ios::trunc | std::ios::binary;
- std::string *errMsg = NULL;
- Module *bigOne = modules[0];
- Linker theLinker("LinkTimeOptimizer", bigOne, false);
- for (unsigned i = 1, e = modules.size(); i != e; ++i)
- if (theLinker.LinkModules(bigOne, modules[i], errMsg))
- return LTO_MODULE_MERGE_FAILURE;
- // all modules have been handed off to the linker.
- modules.clear();
-
- sys::Path FinalOutputPath(FinalOutputFilename);
- FinalOutputPath.eraseSuffix();
-
- switch(CGModel) {
- case LTO_CGM_Dynamic:
- Target->setRelocationModel(Reloc::PIC_);
- break;
- case LTO_CGM_DynamicNoPIC:
- Target->setRelocationModel(Reloc::DynamicNoPIC);
- break;
- case LTO_CGM_Static:
- Target->setRelocationModel(Reloc::Static);
- break;
- }
-
- if (saveTemps) {
- std::string tempFileName(FinalOutputPath.c_str());
- tempFileName += "0.bc";
- std::ofstream Out(tempFileName.c_str(), io_mode);
- WriteBitcodeToFile(bigOne, Out);
- }
-
- // Strip leading underscore because it was added to match names
- // seen by linker.
- for (unsigned i = 0, e = exportList.size(); i != e; ++i) {
- const char *name = exportList[i];
- NameToSymbolMap::iterator itr = allSymbols.find(name);
- if (itr != allSymbols.end())
- exportList[i] = allSymbols[name]->getName();
- }
-
-
- std::string ErrMsg;
- sys::Path TempDir = sys::Path::GetTemporaryDirectory(&ErrMsg);
- if (TempDir.isEmpty()) {
- cerr << "lto: " << ErrMsg << "\n";
- return LTO_WRITE_FAILURE;
- }
- sys::Path tmpAsmFilePath(TempDir);
- if (!tmpAsmFilePath.appendComponent("lto")) {
- cerr << "lto: " << ErrMsg << "\n";
- TempDir.eraseFromDisk(true);
- return LTO_WRITE_FAILURE;
- }
- if (tmpAsmFilePath.createTemporaryFileOnDisk(true, &ErrMsg)) {
- cerr << "lto: " << ErrMsg << "\n";
- TempDir.eraseFromDisk(true);
- return LTO_WRITE_FAILURE;
- }
- sys::RemoveFileOnSignal(tmpAsmFilePath);
-
- std::ofstream asmFile(tmpAsmFilePath.c_str(), io_mode);
- if (!asmFile.is_open() || asmFile.bad()) {
- if (tmpAsmFilePath.exists()) {
- tmpAsmFilePath.eraseFromDisk();
- TempDir.eraseFromDisk(true);
- }
- return LTO_WRITE_FAILURE;
- }
-
- enum LTOStatus status = optimize(bigOne, asmFile, exportList);
- asmFile.close();
- if (status != LTO_OPT_SUCCESS) {
- tmpAsmFilePath.eraseFromDisk();
- TempDir.eraseFromDisk(true);
- return status;
- }
-
- if (saveTemps) {
- std::string tempFileName(FinalOutputPath.c_str());
- tempFileName += "1.bc";
- std::ofstream Out(tempFileName.c_str(), io_mode);
- WriteBitcodeToFile(bigOne, Out);
- }
-
- targetTriple = bigOne->getTargetTriple();
-
- // Run GCC to assemble and link the program into native code.
- //
- // Note:
- // We can't just assemble and link the file with the system assembler
- // and linker because we don't know where to put the _start symbol.
- // GCC mysteriously knows how to do it.
- const sys::Path gcc = sys::Program::FindProgramByName("gcc");
- if (gcc.isEmpty()) {
- tmpAsmFilePath.eraseFromDisk();
- TempDir.eraseFromDisk(true);
- return LTO_ASM_FAILURE;
- }
-
- std::vector<const char*> args;
- args.push_back(gcc.c_str());
- if (strncmp(targetTriple.c_str(), "i686-apple-", 11) == 0) {
- args.push_back("-arch");
- args.push_back("i386");
- }
- if (strncmp(targetTriple.c_str(), "x86_64-apple-", 13) == 0) {
- args.push_back("-arch");
- args.push_back("x86_64");
- }
- if (strncmp(targetTriple.c_str(), "powerpc-apple-", 14) == 0) {
- args.push_back("-arch");
- args.push_back("ppc");
- }
- if (strncmp(targetTriple.c_str(), "powerpc64-apple-", 16) == 0) {
- args.push_back("-arch");
- args.push_back("ppc64");
- }
- args.push_back("-c");
- args.push_back("-x");
- args.push_back("assembler");
- args.push_back("-o");
- args.push_back(OutputFilename.c_str());
- args.push_back(tmpAsmFilePath.c_str());
- args.push_back(0);
-
- if (sys::Program::ExecuteAndWait(gcc, &args[0], 0, 0, 0, 0, &ErrMsg)) {
- cerr << "lto: " << ErrMsg << "\n";
- return LTO_ASM_FAILURE;
- }
-
- tmpAsmFilePath.eraseFromDisk();
- TempDir.eraseFromDisk(true);
-
- return LTO_OPT_SUCCESS;
-}
-
-void LTO::printVersion() {
- cl::PrintVersionMessage();
-}
-
-/// Unused pure-virtual destructor. Must remain empty.
-LinkTimeOptimizer::~LinkTimeOptimizer() {}
-
-/// Destruct LTO. Delete all modules, symbols and target.
-LTO::~LTO() {
-
- for (std::vector<Module *>::iterator itr = modules.begin(), e = modules.end();
- itr != e; ++itr)
- delete *itr;
-
- modules.clear();
-
- for (NameToSymbolMap::iterator itr = allSymbols.begin(), e = allSymbols.end();
- itr != e; ++itr)
- delete itr->second;
-
- allSymbols.clear();
-
- delete Target;
-}
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