| //===--- BackendUtil.cpp - LLVM Backend Utilities -------------------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "clang/CodeGen/BackendUtil.h" |
| #include "clang/Basic/Diagnostic.h" |
| #include "clang/Basic/TargetOptions.h" |
| #include "clang/Frontend/CodeGenOptions.h" |
| #include "clang/Frontend/FrontendDiagnostic.h" |
| #include "llvm/Module.h" |
| #include "llvm/PassManager.h" |
| #include "llvm/Assembly/PrintModulePass.h" |
| #include "llvm/Bitcode/ReaderWriter.h" |
| #include "llvm/CodeGen/RegAllocRegistry.h" |
| #include "llvm/CodeGen/SchedulerRegistry.h" |
| #include "llvm/Support/CommandLine.h" |
| #include "llvm/Support/FormattedStream.h" |
| #include "llvm/Support/PrettyStackTrace.h" |
| #include "llvm/Support/StandardPasses.h" |
| #include "llvm/Support/Timer.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Target/SubtargetFeature.h" |
| #include "llvm/Target/TargetData.h" |
| #include "llvm/Target/TargetLibraryInfo.h" |
| #include "llvm/Target/TargetMachine.h" |
| #include "llvm/Target/TargetOptions.h" |
| #include "llvm/Target/TargetRegistry.h" |
| using namespace clang; |
| using namespace llvm; |
| |
| namespace { |
| |
| class EmitAssemblyHelper { |
| Diagnostic &Diags; |
| const CodeGenOptions &CodeGenOpts; |
| const TargetOptions &TargetOpts; |
| Module *TheModule; |
| |
| Timer CodeGenerationTime; |
| |
| mutable PassManager *CodeGenPasses; |
| mutable PassManager *PerModulePasses; |
| mutable FunctionPassManager *PerFunctionPasses; |
| |
| private: |
| PassManager *getCodeGenPasses() const { |
| if (!CodeGenPasses) { |
| CodeGenPasses = new PassManager(); |
| CodeGenPasses->add(new TargetData(TheModule)); |
| } |
| return CodeGenPasses; |
| } |
| |
| PassManager *getPerModulePasses() const { |
| if (!PerModulePasses) { |
| PerModulePasses = new PassManager(); |
| PerModulePasses->add(new TargetData(TheModule)); |
| } |
| return PerModulePasses; |
| } |
| |
| FunctionPassManager *getPerFunctionPasses() const { |
| if (!PerFunctionPasses) { |
| PerFunctionPasses = new FunctionPassManager(TheModule); |
| PerFunctionPasses->add(new TargetData(TheModule)); |
| } |
| return PerFunctionPasses; |
| } |
| |
| void CreatePasses(); |
| |
| /// AddEmitPasses - Add passes necessary to emit assembly or LLVM IR. |
| /// |
| /// \return True on success. |
| bool AddEmitPasses(BackendAction Action, formatted_raw_ostream &OS); |
| |
| public: |
| EmitAssemblyHelper(Diagnostic &_Diags, |
| const CodeGenOptions &CGOpts, const TargetOptions &TOpts, |
| Module *M) |
| : Diags(_Diags), CodeGenOpts(CGOpts), TargetOpts(TOpts), |
| TheModule(M), CodeGenerationTime("Code Generation Time"), |
| CodeGenPasses(0), PerModulePasses(0), PerFunctionPasses(0) {} |
| |
| ~EmitAssemblyHelper() { |
| delete CodeGenPasses; |
| delete PerModulePasses; |
| delete PerFunctionPasses; |
| } |
| |
| void EmitAssembly(BackendAction Action, raw_ostream *OS); |
| }; |
| |
| } |
| |
| void EmitAssemblyHelper::CreatePasses() { |
| unsigned OptLevel = CodeGenOpts.OptimizationLevel; |
| CodeGenOptions::InliningMethod Inlining = CodeGenOpts.Inlining; |
| |
| // Handle disabling of LLVM optimization, where we want to preserve the |
| // internal module before any optimization. |
| if (CodeGenOpts.DisableLLVMOpts) { |
| OptLevel = 0; |
| Inlining = CodeGenOpts.NoInlining; |
| } |
| |
| FunctionPassManager *FPM = getPerFunctionPasses(); |
| |
| TargetLibraryInfo *TLI = |
| new TargetLibraryInfo(Triple(TheModule->getTargetTriple())); |
| if (!CodeGenOpts.SimplifyLibCalls) |
| TLI->disableAllFunctions(); |
| FPM->add(TLI); |
| |
| // In -O0 if checking is disabled, we don't even have per-function passes. |
| if (CodeGenOpts.VerifyModule) |
| FPM->add(createVerifierPass()); |
| |
| // Assume that standard function passes aren't run for -O0. |
| if (OptLevel > 0) |
| llvm::createStandardFunctionPasses(FPM, OptLevel); |
| |
| llvm::Pass *InliningPass = 0; |
| switch (Inlining) { |
| case CodeGenOptions::NoInlining: break; |
| case CodeGenOptions::NormalInlining: { |
| // Set the inline threshold following llvm-gcc. |
| // |
| // FIXME: Derive these constants in a principled fashion. |
| unsigned Threshold = 225; |
| if (CodeGenOpts.OptimizeSize) |
| Threshold = 75; |
| else if (OptLevel > 2) |
| Threshold = 275; |
| InliningPass = createFunctionInliningPass(Threshold); |
| break; |
| } |
| case CodeGenOptions::OnlyAlwaysInlining: |
| InliningPass = createAlwaysInlinerPass(); // Respect always_inline |
| break; |
| } |
| |
| PassManager *MPM = getPerModulePasses(); |
| |
| TLI = new TargetLibraryInfo(Triple(TheModule->getTargetTriple())); |
| if (!CodeGenOpts.SimplifyLibCalls) |
| TLI->disableAllFunctions(); |
| MPM->add(TLI); |
| |
| // For now we always create per module passes. |
| llvm::createStandardModulePasses(MPM, OptLevel, |
| CodeGenOpts.OptimizeSize, |
| CodeGenOpts.UnitAtATime, |
| CodeGenOpts.UnrollLoops, |
| CodeGenOpts.SimplifyLibCalls, |
| /*HaveExceptions=*/true, |
| InliningPass); |
| } |
| |
| bool EmitAssemblyHelper::AddEmitPasses(BackendAction Action, |
| formatted_raw_ostream &OS) { |
| // Create the TargetMachine for generating code. |
| std::string Error; |
| std::string Triple = TheModule->getTargetTriple(); |
| const llvm::Target *TheTarget = TargetRegistry::lookupTarget(Triple, Error); |
| if (!TheTarget) { |
| Diags.Report(diag::err_fe_unable_to_create_target) << Error; |
| return false; |
| } |
| |
| // FIXME: Expose these capabilities via actual APIs!!!! Aside from just |
| // being gross, this is also totally broken if we ever care about |
| // concurrency. |
| |
| // Set frame pointer elimination mode. |
| if (!CodeGenOpts.DisableFPElim) { |
| llvm::NoFramePointerElim = false; |
| llvm::NoFramePointerElimNonLeaf = false; |
| } else if (CodeGenOpts.OmitLeafFramePointer) { |
| llvm::NoFramePointerElim = false; |
| llvm::NoFramePointerElimNonLeaf = true; |
| } else { |
| llvm::NoFramePointerElim = true; |
| llvm::NoFramePointerElimNonLeaf = true; |
| } |
| |
| // Set float ABI type. |
| if (CodeGenOpts.FloatABI == "soft") |
| llvm::FloatABIType = llvm::FloatABI::Soft; |
| else if (CodeGenOpts.FloatABI == "hard") |
| llvm::FloatABIType = llvm::FloatABI::Hard; |
| else { |
| assert(CodeGenOpts.FloatABI.empty() && "Invalid float abi!"); |
| llvm::FloatABIType = llvm::FloatABI::Default; |
| } |
| |
| llvm::LessPreciseFPMADOption = CodeGenOpts.LessPreciseFPMAD; |
| llvm::NoInfsFPMath = CodeGenOpts.NoInfsFPMath; |
| llvm::NoNaNsFPMath = CodeGenOpts.NoNaNsFPMath; |
| NoZerosInBSS = CodeGenOpts.NoZeroInitializedInBSS; |
| llvm::UnsafeFPMath = CodeGenOpts.UnsafeFPMath; |
| llvm::UseSoftFloat = CodeGenOpts.SoftFloat; |
| UnwindTablesMandatory = CodeGenOpts.UnwindTables; |
| |
| TargetMachine::setAsmVerbosityDefault(CodeGenOpts.AsmVerbose); |
| |
| TargetMachine::setFunctionSections(CodeGenOpts.FunctionSections); |
| TargetMachine::setDataSections (CodeGenOpts.DataSections); |
| |
| // FIXME: Parse this earlier. |
| if (CodeGenOpts.RelocationModel == "static") { |
| TargetMachine::setRelocationModel(llvm::Reloc::Static); |
| } else if (CodeGenOpts.RelocationModel == "pic") { |
| TargetMachine::setRelocationModel(llvm::Reloc::PIC_); |
| } else { |
| assert(CodeGenOpts.RelocationModel == "dynamic-no-pic" && |
| "Invalid PIC model!"); |
| TargetMachine::setRelocationModel(llvm::Reloc::DynamicNoPIC); |
| } |
| // FIXME: Parse this earlier. |
| if (CodeGenOpts.CodeModel == "small") { |
| TargetMachine::setCodeModel(llvm::CodeModel::Small); |
| } else if (CodeGenOpts.CodeModel == "kernel") { |
| TargetMachine::setCodeModel(llvm::CodeModel::Kernel); |
| } else if (CodeGenOpts.CodeModel == "medium") { |
| TargetMachine::setCodeModel(llvm::CodeModel::Medium); |
| } else if (CodeGenOpts.CodeModel == "large") { |
| TargetMachine::setCodeModel(llvm::CodeModel::Large); |
| } else { |
| assert(CodeGenOpts.CodeModel.empty() && "Invalid code model!"); |
| TargetMachine::setCodeModel(llvm::CodeModel::Default); |
| } |
| |
| std::vector<const char *> BackendArgs; |
| BackendArgs.push_back("clang"); // Fake program name. |
| if (!CodeGenOpts.DebugPass.empty()) { |
| BackendArgs.push_back("-debug-pass"); |
| BackendArgs.push_back(CodeGenOpts.DebugPass.c_str()); |
| } |
| if (!CodeGenOpts.LimitFloatPrecision.empty()) { |
| BackendArgs.push_back("-limit-float-precision"); |
| BackendArgs.push_back(CodeGenOpts.LimitFloatPrecision.c_str()); |
| } |
| if (llvm::TimePassesIsEnabled) |
| BackendArgs.push_back("-time-passes"); |
| BackendArgs.push_back(0); |
| llvm::cl::ParseCommandLineOptions(BackendArgs.size() - 1, |
| const_cast<char **>(&BackendArgs[0])); |
| |
| std::string FeaturesStr; |
| if (TargetOpts.CPU.size() || TargetOpts.Features.size()) { |
| SubtargetFeatures Features; |
| Features.setCPU(TargetOpts.CPU); |
| for (std::vector<std::string>::const_iterator |
| it = TargetOpts.Features.begin(), |
| ie = TargetOpts.Features.end(); it != ie; ++it) |
| Features.AddFeature(*it); |
| FeaturesStr = Features.getString(); |
| } |
| TargetMachine *TM = TheTarget->createTargetMachine(Triple, FeaturesStr); |
| |
| if (CodeGenOpts.RelaxAll) |
| TM->setMCRelaxAll(true); |
| |
| // Create the code generator passes. |
| PassManager *PM = getCodeGenPasses(); |
| CodeGenOpt::Level OptLevel = CodeGenOpt::Default; |
| |
| switch (CodeGenOpts.OptimizationLevel) { |
| default: break; |
| case 0: OptLevel = CodeGenOpt::None; break; |
| case 3: OptLevel = CodeGenOpt::Aggressive; break; |
| } |
| |
| // Normal mode, emit a .s or .o file by running the code generator. Note, |
| // this also adds codegenerator level optimization passes. |
| TargetMachine::CodeGenFileType CGFT = TargetMachine::CGFT_AssemblyFile; |
| if (Action == Backend_EmitObj) |
| CGFT = TargetMachine::CGFT_ObjectFile; |
| else if (Action == Backend_EmitMCNull) |
| CGFT = TargetMachine::CGFT_Null; |
| else |
| assert(Action == Backend_EmitAssembly && "Invalid action!"); |
| if (TM->addPassesToEmitFile(*PM, OS, CGFT, OptLevel, |
| /*DisableVerify=*/!CodeGenOpts.VerifyModule)) { |
| Diags.Report(diag::err_fe_unable_to_interface_with_target); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| void EmitAssemblyHelper::EmitAssembly(BackendAction Action, raw_ostream *OS) { |
| TimeRegion Region(llvm::TimePassesIsEnabled ? &CodeGenerationTime : 0); |
| llvm::formatted_raw_ostream FormattedOS; |
| |
| CreatePasses(); |
| switch (Action) { |
| case Backend_EmitNothing: |
| break; |
| |
| case Backend_EmitBC: |
| getPerModulePasses()->add(createBitcodeWriterPass(*OS)); |
| break; |
| |
| case Backend_EmitLL: |
| FormattedOS.setStream(*OS, formatted_raw_ostream::PRESERVE_STREAM); |
| getPerModulePasses()->add(createPrintModulePass(&FormattedOS)); |
| break; |
| |
| default: |
| FormattedOS.setStream(*OS, formatted_raw_ostream::PRESERVE_STREAM); |
| if (!AddEmitPasses(Action, FormattedOS)) |
| return; |
| } |
| |
| // 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 = TheModule->begin(), |
| E = TheModule->end(); I != E; ++I) |
| if (!I->isDeclaration()) |
| PerFunctionPasses->run(*I); |
| PerFunctionPasses->doFinalization(); |
| } |
| |
| if (PerModulePasses) { |
| PrettyStackTraceString CrashInfo("Per-module optimization passes"); |
| PerModulePasses->run(*TheModule); |
| } |
| |
| if (CodeGenPasses) { |
| PrettyStackTraceString CrashInfo("Code generation"); |
| CodeGenPasses->run(*TheModule); |
| } |
| } |
| |
| void clang::EmitBackendOutput(Diagnostic &Diags, const CodeGenOptions &CGOpts, |
| const TargetOptions &TOpts, Module *M, |
| BackendAction Action, raw_ostream *OS) { |
| EmitAssemblyHelper AsmHelper(Diags, CGOpts, TOpts, M); |
| |
| AsmHelper.EmitAssembly(Action, OS); |
| } |