| //===--- Backend.cpp - Interface to LLVM backend technologies -------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "ASTConsumers.h" |
| #include "clang/AST/ASTContext.h" |
| #include "clang/AST/ASTConsumer.h" |
| #include "clang/AST/TranslationUnit.h" |
| #include "clang/Basic/TargetInfo.h" |
| #include "clang/CodeGen/ModuleBuilder.h" |
| #include "clang/Frontend/CompileOptions.h" |
| #include "llvm/Module.h" |
| #include "llvm/ModuleProvider.h" |
| #include "llvm/PassManager.h" |
| #include "llvm/ADT/OwningPtr.h" |
| #include "llvm/Assembly/PrintModulePass.h" |
| #include "llvm/Analysis/CallGraph.h" |
| #include "llvm/Analysis/Verifier.h" |
| #include "llvm/Bitcode/ReaderWriter.h" |
| #include "llvm/CodeGen/RegAllocRegistry.h" |
| #include "llvm/CodeGen/SchedulerRegistry.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Support/Compiler.h" |
| #include "llvm/Support/Timer.h" |
| #include "llvm/System/Path.h" |
| #include "llvm/System/Program.h" |
| #include "llvm/Target/SubtargetFeature.h" |
| #include "llvm/Target/TargetData.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include "llvm/Target/TargetMachineRegistry.h" |
| #include "llvm/Transforms/Scalar.h" |
| #include "llvm/Transforms/IPO.h" |
| using namespace clang; |
| using namespace llvm; |
| |
| namespace { |
| class VISIBILITY_HIDDEN BackendConsumer : public ASTConsumer { |
| BackendAction Action; |
| CompileOptions CompileOpts; |
| const std::string &InputFile; |
| std::string OutputFile; |
| bool GenerateDebugInfo; |
| ASTContext *Context; |
| |
| Timer LLVMIRGeneration; |
| Timer CodeGenerationTime; |
| |
| llvm::OwningPtr<CodeGenerator> Gen; |
| |
| llvm::Module *TheModule; |
| llvm::TargetData *TheTargetData; |
| llvm::raw_ostream *AsmOutStream; |
| |
| mutable llvm::ModuleProvider *ModuleProvider; |
| mutable FunctionPassManager *CodeGenPasses; |
| mutable PassManager *PerModulePasses; |
| mutable FunctionPassManager *PerFunctionPasses; |
| |
| FunctionPassManager *getCodeGenPasses() const; |
| PassManager *getPerModulePasses() const; |
| FunctionPassManager *getPerFunctionPasses() const; |
| |
| void CreatePasses(); |
| |
| /// AddEmitPasses - Add passes necessary to emit assembly or LLVM |
| /// IR. |
| /// |
| /// \return True on success. On failure \arg Error will be set to |
| /// a user readable error message. |
| bool AddEmitPasses(std::string &Error); |
| |
| void EmitAssembly(); |
| |
| public: |
| BackendConsumer(BackendAction action, Diagnostic &Diags, |
| const LangOptions &langopts, const CompileOptions &compopts, |
| const std::string &infile, const std::string &outfile, |
| bool debug) : |
| Action(action), |
| CompileOpts(compopts), |
| InputFile(infile), |
| OutputFile(outfile), |
| GenerateDebugInfo(debug), |
| LLVMIRGeneration("LLVM IR Generation Time"), |
| CodeGenerationTime("Code Generation Time"), |
| Gen(CreateLLVMCodeGen(Diags, langopts, InputFile, GenerateDebugInfo)), |
| TheModule(0), TheTargetData(0), AsmOutStream(0), ModuleProvider(0), |
| CodeGenPasses(0), PerModulePasses(0), PerFunctionPasses(0) { |
| |
| // Enable -time-passes if -ftime-report is enabled. |
| llvm::TimePassesIsEnabled = CompileOpts.TimePasses; |
| } |
| |
| ~BackendConsumer() { |
| delete AsmOutStream; |
| delete TheTargetData; |
| delete ModuleProvider; |
| delete CodeGenPasses; |
| delete PerModulePasses; |
| delete PerFunctionPasses; |
| } |
| |
| virtual void InitializeTU(TranslationUnit& TU) { |
| Context = &TU.getContext(); |
| |
| if (CompileOpts.TimePasses) |
| LLVMIRGeneration.startTimer(); |
| |
| Gen->InitializeTU(TU); |
| |
| TheModule = Gen->GetModule(); |
| ModuleProvider = new ExistingModuleProvider(TheModule); |
| TheTargetData = |
| new llvm::TargetData(TU.getContext().Target.getTargetDescription()); |
| |
| if (CompileOpts.TimePasses) |
| LLVMIRGeneration.stopTimer(); |
| } |
| |
| virtual void HandleTopLevelDecl(Decl *D) { |
| PrettyStackTraceDecl CrashInfo(D, SourceLocation(), |
| Context->getSourceManager(), |
| "LLVM IR generation of declaration"); |
| if (CompileOpts.TimePasses) |
| LLVMIRGeneration.startTimer(); |
| |
| Gen->HandleTopLevelDecl(D); |
| |
| if (CompileOpts.TimePasses) |
| LLVMIRGeneration.stopTimer(); |
| } |
| |
| virtual void HandleTranslationUnit(TranslationUnit& TU) { |
| { |
| PrettyStackTraceString CrashInfo("per-file LLVM IR generation"); |
| if (CompileOpts.TimePasses) |
| LLVMIRGeneration.startTimer(); |
| |
| Gen->HandleTranslationUnit(TU); |
| |
| if (CompileOpts.TimePasses) |
| LLVMIRGeneration.stopTimer(); |
| } |
| |
| // EmitAssembly times and registers crash info itself. |
| EmitAssembly(); |
| |
| // Force a flush here in case we never get released. |
| if (AsmOutStream) |
| AsmOutStream->flush(); |
| } |
| |
| virtual void HandleTagDeclDefinition(TagDecl *D) { |
| PrettyStackTraceDecl CrashInfo(D, SourceLocation(), |
| Context->getSourceManager(), |
| "LLVM IR generation of declaration"); |
| Gen->HandleTagDeclDefinition(D); |
| } |
| }; |
| } |
| |
| FunctionPassManager *BackendConsumer::getCodeGenPasses() const { |
| if (!CodeGenPasses) { |
| CodeGenPasses = new FunctionPassManager(ModuleProvider); |
| CodeGenPasses->add(new TargetData(*TheTargetData)); |
| } |
| |
| return CodeGenPasses; |
| } |
| |
| PassManager *BackendConsumer::getPerModulePasses() const { |
| if (!PerModulePasses) { |
| PerModulePasses = new PassManager(); |
| PerModulePasses->add(new TargetData(*TheTargetData)); |
| } |
| |
| return PerModulePasses; |
| } |
| |
| FunctionPassManager *BackendConsumer::getPerFunctionPasses() const { |
| if (!PerFunctionPasses) { |
| PerFunctionPasses = new FunctionPassManager(ModuleProvider); |
| PerFunctionPasses->add(new TargetData(*TheTargetData)); |
| } |
| |
| return PerFunctionPasses; |
| } |
| |
| bool BackendConsumer::AddEmitPasses(std::string &Error) { |
| if (Action == Backend_EmitNothing) |
| return true; |
| |
| if (OutputFile == "-" || (InputFile == "-" && OutputFile.empty())) { |
| AsmOutStream = new raw_stdout_ostream(); |
| sys::Program::ChangeStdoutToBinary(); |
| } else { |
| if (OutputFile.empty()) { |
| llvm::sys::Path Path(InputFile); |
| Path.eraseSuffix(); |
| if (Action == Backend_EmitBC) { |
| Path.appendSuffix("bc"); |
| } else if (Action == Backend_EmitLL) { |
| Path.appendSuffix("ll"); |
| } else { |
| Path.appendSuffix("s"); |
| } |
| OutputFile = Path.toString(); |
| } |
| |
| AsmOutStream = new raw_fd_ostream(OutputFile.c_str(), true, Error); |
| if (!Error.empty()) |
| return false; |
| } |
| |
| if (Action == Backend_EmitBC) { |
| getPerModulePasses()->add(createBitcodeWriterPass(*AsmOutStream)); |
| } else if (Action == Backend_EmitLL) { |
| getPerModulePasses()->add(createPrintModulePass(AsmOutStream)); |
| } else { |
| bool Fast = CompileOpts.OptimizationLevel == 0; |
| |
| // Create the TargetMachine for generating code. |
| const TargetMachineRegistry::entry *TME = |
| TargetMachineRegistry::getClosestStaticTargetForModule(*TheModule, Error); |
| if (!TME) { |
| Error = std::string("Unable to get target machine: ") + Error; |
| return false; |
| } |
| |
| std::string FeaturesStr; |
| if (CompileOpts.CPU.size() || CompileOpts.Features.size()) { |
| SubtargetFeatures Features; |
| Features.setCPU(CompileOpts.CPU); |
| for (std::vector<std::string>::iterator |
| it = CompileOpts.Features.begin(), |
| ie = CompileOpts.Features.end(); it != ie; ++it) |
| Features.AddFeature(*it); |
| FeaturesStr = Features.getString(); |
| } |
| TargetMachine *TM = TME->CtorFn(*TheModule, FeaturesStr); |
| |
| // Set register scheduler & allocation policy. |
| RegisterScheduler::setDefault(createDefaultScheduler); |
| RegisterRegAlloc::setDefault(Fast ? createLocalRegisterAllocator : |
| createLinearScanRegisterAllocator); |
| |
| // From llvm-gcc: |
| // If there are passes we have to run on the entire module, we do codegen |
| // as a separate "pass" after that happens. |
| // FIXME: This is disabled right now until bugs can be worked out. Reenable |
| // this for fast -O0 compiles! |
| FunctionPassManager *PM = getCodeGenPasses(); |
| |
| // Normal mode, emit a .s file by running the code generator. |
| // Note, this also adds codegenerator level optimization passes. |
| switch (TM->addPassesToEmitFile(*PM, *AsmOutStream, |
| TargetMachine::AssemblyFile, Fast)) { |
| default: |
| case FileModel::Error: |
| Error = "Unable to interface with target machine!\n"; |
| return false; |
| case FileModel::AsmFile: |
| break; |
| } |
| |
| if (TM->addPassesToEmitFileFinish(*CodeGenPasses, 0, Fast)) { |
| Error = "Unable to interface with target machine!\n"; |
| return false; |
| } |
| } |
| |
| return true; |
| } |
| |
| void BackendConsumer::CreatePasses() { |
| // In -O0 if checking is disabled, we don't even have per-function passes. |
| if (CompileOpts.VerifyModule) |
| getPerFunctionPasses()->add(createVerifierPass()); |
| |
| if (CompileOpts.OptimizationLevel > 0) { |
| FunctionPassManager *PM = getPerFunctionPasses(); |
| PM->add(createCFGSimplificationPass()); |
| if (CompileOpts.OptimizationLevel == 1) |
| PM->add(createPromoteMemoryToRegisterPass()); |
| else |
| PM->add(createScalarReplAggregatesPass()); |
| PM->add(createInstructionCombiningPass()); |
| } |
| |
| // For now we always create per module passes. |
| PassManager *PM = getPerModulePasses(); |
| if (CompileOpts.OptimizationLevel > 0) { |
| if (CompileOpts.UnitAtATime) |
| PM->add(createRaiseAllocationsPass()); // call %malloc -> malloc inst |
| PM->add(createCFGSimplificationPass()); // Clean up disgusting code |
| PM->add(createPromoteMemoryToRegisterPass()); // Kill useless allocas |
| if (CompileOpts.UnitAtATime) { |
| PM->add(createGlobalOptimizerPass()); // Optimize out global vars |
| PM->add(createGlobalDCEPass()); // Remove unused fns and globs |
| PM->add(createIPConstantPropagationPass()); // IP Constant Propagation |
| PM->add(createDeadArgEliminationPass()); // Dead argument elimination |
| } |
| PM->add(createInstructionCombiningPass()); // Clean up after IPCP & DAE |
| PM->add(createCFGSimplificationPass()); // Clean up after IPCP & DAE |
| if (CompileOpts.UnitAtATime) { |
| PM->add(createPruneEHPass()); // Remove dead EH info |
| PM->add(createFunctionAttrsPass()); // Set readonly/readnone attrs |
| } |
| if (CompileOpts.InlineFunctions) |
| PM->add(createFunctionInliningPass()); // Inline small functions |
| else |
| PM->add(createAlwaysInlinerPass()); // Respect always_inline |
| if (CompileOpts.OptimizationLevel > 2) |
| PM->add(createArgumentPromotionPass()); // Scalarize uninlined fn args |
| if (CompileOpts.SimplifyLibCalls) |
| PM->add(createSimplifyLibCallsPass()); // Library Call Optimizations |
| PM->add(createInstructionCombiningPass()); // Cleanup for scalarrepl. |
| PM->add(createJumpThreadingPass()); // Thread jumps. |
| PM->add(createCFGSimplificationPass()); // Merge & remove BBs |
| PM->add(createScalarReplAggregatesPass()); // Break up aggregate allocas |
| PM->add(createInstructionCombiningPass()); // Combine silly seq's |
| PM->add(createCondPropagationPass()); // Propagate conditionals |
| PM->add(createTailCallEliminationPass()); // Eliminate tail calls |
| PM->add(createCFGSimplificationPass()); // Merge & remove BBs |
| PM->add(createReassociatePass()); // Reassociate expressions |
| PM->add(createLoopRotatePass()); // Rotate Loop |
| PM->add(createLICMPass()); // Hoist loop invariants |
| PM->add(createLoopUnswitchPass(CompileOpts.OptimizeSize ? true : false)); |
| // PM->add(createLoopIndexSplitPass()); // Split loop index |
| PM->add(createInstructionCombiningPass()); |
| PM->add(createIndVarSimplifyPass()); // Canonicalize indvars |
| PM->add(createLoopDeletionPass()); // Delete dead loops |
| if (CompileOpts.UnrollLoops) |
| PM->add(createLoopUnrollPass()); // Unroll small loops |
| PM->add(createInstructionCombiningPass()); // Clean up after the unroller |
| PM->add(createGVNPass()); // Remove redundancies |
| PM->add(createMemCpyOptPass()); // Remove memcpy / form memset |
| PM->add(createSCCPPass()); // Constant prop with SCCP |
| |
| // Run instcombine after redundancy elimination to exploit opportunities |
| // opened up by them. |
| PM->add(createInstructionCombiningPass()); |
| PM->add(createCondPropagationPass()); // Propagate conditionals |
| PM->add(createDeadStoreEliminationPass()); // Delete dead stores |
| PM->add(createAggressiveDCEPass()); // Delete dead instructions |
| PM->add(createCFGSimplificationPass()); // Merge & remove BBs |
| |
| if (CompileOpts.UnitAtATime) { |
| PM->add(createStripDeadPrototypesPass()); // Get rid of dead prototypes |
| PM->add(createDeadTypeEliminationPass()); // Eliminate dead types |
| } |
| |
| if (CompileOpts.OptimizationLevel > 1 && CompileOpts.UnitAtATime) |
| PM->add(createConstantMergePass()); // Merge dup global constants |
| } else { |
| PM->add(createAlwaysInlinerPass()); |
| } |
| } |
| |
| /// EmitAssembly - Handle interaction with LLVM backend to generate |
| /// actual machine code. |
| void BackendConsumer::EmitAssembly() { |
| // Silently ignore if we weren't initialized for some reason. |
| if (!TheModule || !TheTargetData) |
| return; |
| |
| |
| TimeRegion Region(CompileOpts.TimePasses ? &CodeGenerationTime : 0); |
| |
| // Make sure IR generation is happy with the module. This is |
| // released by the module provider. |
| Module *M = Gen->ReleaseModule(); |
| if (!M) { |
| // The module has been released by IR gen on failures, do not |
| // double free. |
| ModuleProvider->releaseModule(); |
| TheModule = 0; |
| return; |
| } |
| |
| assert(TheModule == M && "Unexpected module change during IR generation"); |
| |
| CreatePasses(); |
| |
| std::string Error; |
| if (!AddEmitPasses(Error)) { |
| // FIXME: Don't fail this way. |
| llvm::cerr << "ERROR: " << Error << "\n"; |
| ::exit(1); |
| } |
| |
| // Run passes. For now we do all passes at once, but eventually we |
| // would like to have the option of streaming code generation. |
| |
| if (PerFunctionPasses) { |
| PrettyStackTraceString CrashInfo("per-function optimization"); |
| |
| PerFunctionPasses->doInitialization(); |
| for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I) |
| if (!I->isDeclaration()) |
| PerFunctionPasses->run(*I); |
| PerFunctionPasses->doFinalization(); |
| } |
| |
| if (PerModulePasses) { |
| PrettyStackTraceString CrashInfo("per-module optimization passes"); |
| PerModulePasses->run(*M); |
| } |
| |
| if (CodeGenPasses) { |
| PrettyStackTraceString CrashInfo("code generation"); |
| CodeGenPasses->doInitialization(); |
| for (Module::iterator I = M->begin(), E = M->end(); I != E; ++I) |
| if (!I->isDeclaration()) |
| CodeGenPasses->run(*I); |
| CodeGenPasses->doFinalization(); |
| } |
| } |
| |
| ASTConsumer *clang::CreateBackendConsumer(BackendAction Action, |
| Diagnostic &Diags, |
| const LangOptions &LangOpts, |
| const CompileOptions &CompileOpts, |
| const std::string& InFile, |
| const std::string& OutFile, |
| bool GenerateDebugInfo) { |
| // FIXME: If optimizing, disable all debug info generation. The LLVM |
| // optimizer and backend is not ready to handle it when optimizations |
| // are enabled. |
| if (CompileOpts.OptimizationLevel > 0) |
| GenerateDebugInfo = false; |
| |
| return new BackendConsumer(Action, Diags, LangOpts, CompileOpts, |
| InFile, OutFile, GenerateDebugInfo); |
| } |