C++ FunctionPassManager类代码示例

static void llvm_init(){
    ExecutionEngine *ee = tcg_llvm_ctx->getExecutionEngine();
    FunctionPassManager *fpm = tcg_llvm_ctx->getFunctionPassManager();
    Module *mod = tcg_llvm_ctx->getModule();
    LLVMContext &ctx = mod->getContext();

    // Link logging function in with JIT
    Function *logFunc;
    std::vector<Type*> argTypes;
    // DynValBuffer*
    argTypes.push_back(IntegerType::get(ctx, 8*sizeof(uintptr_t)));
    // DynValEntryType
    argTypes.push_back(IntegerType::get(ctx, 8*sizeof(DynValEntryType)));
    // LogOp
    argTypes.push_back(IntegerType::get(ctx, 8*sizeof(LogOp)));
    // Dynamic value
    argTypes.push_back(IntegerType::get(ctx, 8*sizeof(uintptr_t)));
    logFunc = Function::Create(
            FunctionType::get(Type::getVoidTy(ctx), argTypes, false),
            Function::ExternalLinkage, "log_dynval", mod);
    logFunc->addFnAttr(Attribute::AlwaysInline);
    ee->addGlobalMapping(logFunc, (void*) &log_dynval);
    
    // Create instrumentation pass and add to function pass manager
    llvm::FunctionPass *instfp = createPandaInstrFunctionPass(mod);
    fpm->add(instfp);
    PIFP = static_cast<PandaInstrFunctionPass*>(instfp);
}

/// Optimize merged modules using various IPO passes
bool LTOCodeGenerator::generateAssemblyCode(raw_ostream& out,
                                            std::string& errMsg)
{
    if ( this->determineTarget(errMsg) ) 
        return true;

    // mark which symbols can not be internalized 
    this->applyScopeRestrictions();

    Module* mergedModule = _linker.getModule();

    // if options were requested, set them
    if ( !_codegenOptions.empty() )
        cl::ParseCommandLineOptions(_codegenOptions.size(), 
                                    const_cast<char **>(&_codegenOptions[0]));

    // Instantiate the pass manager to organize the passes.
    PassManager passes;

    // Start off with a verification pass.
    passes.add(createVerifierPass());

    // Add an appropriate TargetData instance for this module...
    passes.add(new TargetData(*_target->getTargetData()));
    
    createStandardLTOPasses(&passes, /*Internalize=*/ false, !DisableInline,
                            /*VerifyEach=*/ false);

    // Make sure everything is still good.
    passes.add(createVerifierPass());

    FunctionPassManager* codeGenPasses = new FunctionPassManager(mergedModule);

    codeGenPasses->add(new TargetData(*_target->getTargetData()));

    formatted_raw_ostream Out(out);

    if (_target->addPassesToEmitFile(*codeGenPasses, Out,
                                     TargetMachine::CGFT_AssemblyFile,
                                     CodeGenOpt::Aggressive)) {
      errMsg = "target file type not supported";
      return true;
    }

    // Run our queue of passes all at once now, efficiently.
    passes.run(*mergedModule);

    // Run the code generator, and write assembly file
    codeGenPasses->doInitialization();

    for (Module::iterator
           it = mergedModule->begin(), e = mergedModule->end(); it != e; ++it)
      if (!it->isDeclaration())
        codeGenPasses->run(*it);

    codeGenPasses->doFinalization();

    return false; // success
}

// Unfortunately, the LLVM C API doesn't provide an easy way of iterating over
// all the functions in a module, so we do that manually here. You'll find
// similar code in clang's BackendUtil.cpp file.
extern "C" void
LLVMRustRunFunctionPassManager(LLVMPassManagerRef PM, LLVMModuleRef M) {
    FunctionPassManager *P = unwrap<FunctionPassManager>(PM);
    P->doInitialization();
    for (Module::iterator I = unwrap(M)->begin(),
         E = unwrap(M)->end(); I != E; ++I)
        if (!I->isDeclaration())
            P->run(*I);
    P->doFinalization();
}

static bool parseFunctionPassName(FunctionPassManager &FPM, StringRef Name) {
  if (Name == "no-op-function") {
    FPM.addPass(NoOpFunctionPass());
    return true;
  }
  if (Name == "print") {
    FPM.addPass(PrintFunctionPass(dbgs()));
    return true;
  }
  return false;
}

void
optimize(cpu_t *cpu)
{
	FunctionPassManager pm = FunctionPassManager(cpu->mod);

	pm.add(createPromoteMemoryToRegisterPass());
	pm.add(createInstructionCombiningPass());
	pm.add(createConstantPropagationPass());
	pm.add(createDeadCodeEliminationPass());
	pm.run(*cpu->cur_func);
}

bool PassBuilder::parseFunctionPassPipeline(FunctionPassManager &FPM,
                                            StringRef &PipelineText,
                                            bool VerifyEachPass,
                                            bool DebugLogging) {
  for (;;) {
    // Parse nested pass managers by recursing.
    if (PipelineText.startswith("function(")) {
      FunctionPassManager NestedFPM(DebugLogging);

      // Parse the inner pipeline inte the nested manager.
      PipelineText = PipelineText.substr(strlen("function("));
      if (!parseFunctionPassPipeline(NestedFPM, PipelineText, VerifyEachPass,
                                     DebugLogging) ||
          PipelineText.empty())
        return false;
      assert(PipelineText[0] == ')');
      PipelineText = PipelineText.substr(1);

      // Add the nested pass manager with the appropriate adaptor.
      FPM.addPass(std::move(NestedFPM));
    } else if (PipelineText.startswith("loop(")) {
      LoopPassManager NestedLPM(DebugLogging);

      // Parse the inner pipeline inte the nested manager.
      PipelineText = PipelineText.substr(strlen("loop("));
      if (!parseLoopPassPipeline(NestedLPM, PipelineText, VerifyEachPass,
                                 DebugLogging) ||
          PipelineText.empty())
        return false;
      assert(PipelineText[0] == ')');
      PipelineText = PipelineText.substr(1);

      // Add the nested pass manager with the appropriate adaptor.
      FPM.addPass(createFunctionToLoopPassAdaptor(std::move(NestedLPM)));
    } else {
      // Otherwise try to parse a pass name.
      size_t End = PipelineText.find_first_of(",)");
      if (!parseFunctionPassName(FPM, PipelineText.substr(0, End)))
        return false;
      if (VerifyEachPass)
        FPM.addPass(VerifierPass());

      PipelineText = PipelineText.substr(End);
    }

    if (PipelineText.empty() || PipelineText[0] == ')')
      return true;

    assert(PipelineText[0] == ',');
    PipelineText = PipelineText.substr(1);
  }
}

ExecutionEngine *MCJITHelper::compileModule(Module *M) {
  if (M == OpenModule)
    closeCurrentModule();

  std::string ErrStr;
  ExecutionEngine *NewEngine = EngineBuilder(M)
                                            .setErrorStr(&ErrStr)
                                            .setMCJITMemoryManager(new HelpingMemoryManager(this))
                                            .create();
  if (!NewEngine) {
    fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
    exit(1);
  }

  // Create a function pass manager for this engine
  FunctionPassManager *FPM = new FunctionPassManager(M);

  // Set up the optimizer pipeline.  Start with registering info about how the
  // target lays out data structures.
  FPM->add(new DataLayout(*NewEngine->getDataLayout()));
  // Provide basic AliasAnalysis support for GVN.
  FPM->add(createBasicAliasAnalysisPass());
  // Promote allocas to registers.
  FPM->add(createPromoteMemoryToRegisterPass());
  // Do simple "peephole" optimizations and bit-twiddling optzns.
  FPM->add(createInstructionCombiningPass());
  // Reassociate expressions.
  FPM->add(createReassociatePass());
  // Eliminate Common SubExpressions.
  FPM->add(createGVNPass());
  // Simplify the control flow graph (deleting unreachable blocks, etc).
  FPM->add(createCFGSimplificationPass());
  FPM->doInitialization();

  // For each function in the module
  Module::iterator it;
  Module::iterator end = M->end();
  for (it = M->begin(); it != end; ++it) {
    // Run the FPM on this function
    FPM->run(*it);
  }

  // We don't need this anymore
  delete FPM;

  // Store this engine
  EngineMap[M] = NewEngine;
  NewEngine->finalizeObject();

  return NewEngine;
}

/// AddOptimizationPasses - This routine adds optimization passes
/// based on selected optimization level, OptLevel. This routine
/// duplicates llvm-gcc behaviour.
///
/// OptLevel - Optimization Level
static void AddOptimizationPasses(PassManagerBase &MPM,FunctionPassManager &FPM,
                                  unsigned OptLevel, unsigned SizeLevel) {
  FPM.add(createVerifierPass());                  // Verify that input is correct

  PassManagerBuilder Builder;
  Builder.OptLevel = OptLevel;
  Builder.SizeLevel = SizeLevel;

  if (DisableInline) {
    // No inlining pass
  } else if (OptLevel > 1) {
    unsigned Threshold = 225;
    if (SizeLevel == 1)      // -Os
      Threshold = 75;
    else if (SizeLevel == 2) // -Oz
      Threshold = 25;
    if (OptLevel > 2)
      Threshold = 275;
    Builder.Inliner = createFunctionInliningPass(Threshold);
  } else {
    Builder.Inliner = createAlwaysInlinerPass();
  }
  Builder.DisableUnitAtATime = !UnitAtATime;
  Builder.DisableUnrollLoops = OptLevel == 0;
  Builder.DisableSimplifyLibCalls = DisableSimplifyLibCalls;
  
  Builder.populateFunctionPassManager(FPM);
  Builder.populateModulePassManager(MPM);
}

/// This routine adds optimization passes based on selected optimization level,
/// OptLevel.
///
/// OptLevel - Optimization Level
static void AddOptimizationPasses(PassManagerBase &MPM,FunctionPassManager &FPM,
                                  unsigned OptLevel, unsigned SizeLevel) {
  FPM.add(createVerifierPass());          // Verify that input is correct
  MPM.add(createDebugInfoVerifierPass()); // Verify that debug info is correct

  PassManagerBuilder Builder;
  Builder.OptLevel = OptLevel;
  Builder.SizeLevel = SizeLevel;

  if (DisableInline) {
    // No inlining pass
  } else if (OptLevel > 1) {
    Builder.Inliner = createFunctionInliningPass(OptLevel, SizeLevel);
  } else {
    Builder.Inliner = createAlwaysInlinerPass();
  }
  Builder.DisableUnitAtATime = !UnitAtATime;
  Builder.DisableUnrollLoops = (DisableLoopUnrolling.getNumOccurrences() > 0) ?
                               DisableLoopUnrolling : OptLevel == 0;

  // This is final, unless there is a #pragma vectorize enable
  if (DisableLoopVectorization)
    Builder.LoopVectorize = false;
  // If option wasn't forced via cmd line (-vectorize-loops, -loop-vectorize)
  else if (!Builder.LoopVectorize)
    Builder.LoopVectorize = OptLevel > 1 && SizeLevel < 2;

  // When #pragma vectorize is on for SLP, do the same as above
  Builder.SLPVectorize =
      DisableSLPVectorization ? false : OptLevel > 1 && SizeLevel < 2;

  Builder.populateFunctionPassManager(FPM);
  Builder.populateModulePassManager(MPM);
}

Function &OptimizeForRuntime(Function &F) {
#ifdef DEBUG
  static PassManagerBuilder Builder = getDebugBuilder();
#else
  static PassManagerBuilder Builder = getBuilder();
#endif
  Module *M = F.getParent();
  opt::GenerateOutput = true;
  polly::opt::PollyParallel = true;

  FunctionPassManager PM = FunctionPassManager(M);

  Builder.populateFunctionPassManager(PM);
  PM.doInitialization();
  PM.run(F);
  PM.doFinalization();

  if (opt::havePapi()) {
    PassManager MPM;
    Builder.populateModulePassManager(MPM);
    MPM.add(polli::createTraceMarkerPass());
    MPM.run(*M);
  }

  if (opt::haveLikwid()) {
    PassManager MPM;
    Builder.populateModulePassManager(MPM);
    MPM.add(polli::createLikwidMarkerPass());
    MPM.run(*M);
  }

  DEBUG(
  StoreModule(*M, M->getModuleIdentifier() + ".after.polly.ll")
  );
  opt::GenerateOutput = false;

  return F;
}

/**
 * Adds a set of optimization passes to the given module/function pass
 * managers based on the given optimization and size reduction levels.
 *
 * The selection mirrors Clang behavior and is based on LLVM's
 * PassManagerBuilder.
 */
static void addOptimizationPasses(PassManagerBase &mpm, FunctionPassManager &fpm,
                                  unsigned optLevel, unsigned sizeLevel) {
    fpm.add(createVerifierPass());                  // Verify that input is correct

    PassManagerBuilder builder;
    builder.OptLevel = optLevel;
    builder.SizeLevel = sizeLevel;

    if (willInline()) {
        unsigned threshold = 225;
        if (sizeLevel == 1)      // -Os
            threshold = 75;
        else if (sizeLevel == 2) // -Oz
            threshold = 25;
        if (optLevel > 2)
            threshold = 275;
        builder.Inliner = createFunctionInliningPass(threshold);
    } else {
        builder.Inliner = createAlwaysInlinerPass();
    }
    builder.DisableSimplifyLibCalls = disableSimplifyLibCalls;
    builder.DisableUnitAtATime = !unitAtATime;
    builder.DisableUnrollLoops = optLevel == 0;
    /* builder.Vectorize is set in ctor from command line switch */

    if (!disableLangSpecificPasses) {
        if (!disableSimplifyDruntimeCalls)
            builder.addExtension(PassManagerBuilder::EP_LoopOptimizerEnd, addSimplifyDRuntimeCallsPass);

#if USE_METADATA
        if (!disableGCToStack)
            builder.addExtension(PassManagerBuilder::EP_LoopOptimizerEnd, addGarbageCollect2StackPass);
#endif // USE_METADATA
    }

#if LDC_LLVM_VER >= 301
    // EP_OptimizerLast does not exist in LLVM 3.0, add it manually below.
    builder.addExtension(PassManagerBuilder::EP_OptimizerLast, addStripExternalsPass);
#endif

    builder.populateFunctionPassManager(fpm);
    builder.populateModulePassManager(mpm);

#if LDC_LLVM_VER < 301
    addStripExternalsPass(builder, mpm);
#endif
}

FunctionPassManager* Builder::getStandardOptimizer() {
    FunctionPassManager* optimizer = new FunctionPassManager(this->_mod);

    // Set up the optimizer pipeline.  Start with registering info about how the
    // target lays out data structures.
    if (this->_jit) {
        optimizer->add(new DataLayoutPass(*this->_jit->getDataLayout()));
    }
    // Provide basic AliasAnalysis support for GVN.
    optimizer->add(createBasicAliasAnalysisPass());
    // Do simple "peephole" optimizations and bit-twiddling optzns.
    optimizer->add(createInstructionCombiningPass());
    // Reassociate expressions.
    optimizer->add(createReassociatePass());
    // Eliminate Common SubExpressions.
    optimizer->add(createGVNPass());
    // Simplify the control flow graph (deleting unreachable blocks, etc).
    optimizer->add(createCFGSimplificationPass());

    optimizer->doInitialization();
    return optimizer;
}

void
optimize(cpu_t *cpu)
{
	dyncom_engine_t* de = cpu->dyncom_engine;
	FunctionPassManager pm = FunctionPassManager(de->mod);

	std::string data_layout = de->exec_engine->getTargetData()->getStringRepresentation();
	TargetData *TD = new TargetData(data_layout);
	pm.add(TD);
	pm.add(createPromoteMemoryToRegisterPass());
	pm.add(createInstructionCombiningPass());
	pm.add(createConstantPropagationPass());
	pm.add(createDeadCodeEliminationPass());
	pm.run(*de->cur_func);
}

void *MCJITHelper::getPointerToFunction(Function* F) {
  // See if an existing instance of MCJIT has this function.
  EngineVector::iterator begin = Engines.begin();
  EngineVector::iterator end = Engines.end();
  EngineVector::iterator it;
  for (it = begin; it != end; ++it) {
    void *P = (*it)->getPointerToFunction(F);
    if (P)
      return P;
  }

  // If we didn't find the function, see if we can generate it.
  if (OpenModule) {
    std::string ErrStr;
    ExecutionEngine *NewEngine = EngineBuilder(OpenModule)
                                              .setErrorStr(&ErrStr)
                                              .setMCJITMemoryManager(new HelpingMemoryManager(this))
                                              .create();
    if (!NewEngine) {
      fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
      exit(1);
    }

    // Create a function pass manager for this engine
    FunctionPassManager *FPM = new FunctionPassManager(OpenModule);

    // Set up the optimizer pipeline.  Start with registering info about how the
    // target lays out data structures.
    FPM->add(new DataLayout(*NewEngine->getDataLayout()));
    // Provide basic AliasAnalysis support for GVN.
    FPM->add(createBasicAliasAnalysisPass());
    // Promote allocas to registers.
    FPM->add(createPromoteMemoryToRegisterPass());
    // Do simple "peephole" optimizations and bit-twiddling optzns.
    FPM->add(createInstructionCombiningPass());
    // Reassociate expressions.
    FPM->add(createReassociatePass());
    // Eliminate Common SubExpressions.
    FPM->add(createGVNPass());
    // Simplify the control flow graph (deleting unreachable blocks, etc).
    FPM->add(createCFGSimplificationPass());
    FPM->doInitialization();

    // For each function in the module
    Module::iterator it;
    Module::iterator end = OpenModule->end();
    for (it = OpenModule->begin(); it != end; ++it) {
      // Run the FPM on this function
      FPM->run(*it);
    }

    // We don't need this anymore
    delete FPM;

    OpenModule = NULL;
    Engines.push_back(NewEngine);
    NewEngine->finalizeObject();
    return NewEngine->getPointerToFunction(F);
  }
  return NULL;
}

ExecutionEngine *MCJITHelper::compileModule(Module *M) {
    assert(EngineMap.find(M) == EngineMap.end());

    if (M == CurrentModule)
        closeCurrentModule();

    std::string ErrStr;
    ExecutionEngine *EE = EngineBuilder(M)
                          .setErrorStr(&ErrStr)
                          .setMCJITMemoryManager(new HelpingMemoryManager(this))
                          .create();
    if (!EE) {
        fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
        exit(1);
    }

    if (UseObjectCache)
        EE->setObjectCache(&OurObjectCache);
    // Get the ModuleID so we can identify IR input files
    const std::string ModuleID = M->getModuleIdentifier();

    // If we've flagged this as an IR file, it doesn't need function passes run.
    if (0 != ModuleID.compare(0, 3, "IR:")) {
        FunctionPassManager *FPM = 0;

        // Create a FPM for this module
        FPM = new FunctionPassManager(M);

        // Set up the optimizer pipeline.  Start with registering info about how the
        // target lays out data structures.
        FPM->add(new DataLayout(*EE->getDataLayout()));
        // Provide basic AliasAnalysis support for GVN.
        FPM->add(createBasicAliasAnalysisPass());
        // Promote allocas to registers.
        FPM->add(createPromoteMemoryToRegisterPass());
        // Do simple "peephole" optimizations and bit-twiddling optzns.
        FPM->add(createInstructionCombiningPass());
        // Reassociate expressions.
        FPM->add(createReassociatePass());
        // Eliminate Common SubExpressions.
        FPM->add(createGVNPass());
        // Simplify the control flow graph (deleting unreachable blocks, etc).
        FPM->add(createCFGSimplificationPass());

        FPM->doInitialization();

        // For each function in the module
        Module::iterator it;
        Module::iterator end = M->end();
        for (it = M->begin(); it != end; ++it) {
            // Run the FPM on this function
            FPM->run(*it);
        }

        delete FPM;
    }

    EE->finalizeObject();

    // Store this engine
    EngineMap[M] = EE;

    return EE;
}