Exemplo n.º 1
0
/// removeDeadFunctions - Remove dead functions that are not included in
/// DNR (Do Not Remove) list.
bool Inliner::removeDeadFunctions(CallGraph &CG, bool AlwaysInlineOnly) {
  SmallVector<CallGraphNode*, 16> FunctionsToRemove;

  // Scan for all of the functions, looking for ones that should now be removed
  // from the program.  Insert the dead ones in the FunctionsToRemove set.
  for (CallGraph::iterator I = CG.begin(), E = CG.end(); I != E; ++I) {
    CallGraphNode *CGN = I->second;
    Function *F = CGN->getFunction();
    if (!F || F->isDeclaration())
      continue;

    // Handle the case when this function is called and we only want to care
    // about always-inline functions. This is a bit of a hack to share code
    // between here and the InlineAlways pass.
    if (AlwaysInlineOnly &&
        !F->getFnAttributes().hasAttribute(Attribute::AlwaysInline))
      continue;

    // If the only remaining users of the function are dead constants, remove
    // them.
    F->removeDeadConstantUsers();

    if (!F->isDefTriviallyDead())
      continue;
    
    // Remove any call graph edges from the function to its callees.
    CGN->removeAllCalledFunctions();

    // Remove any edges from the external node to the function's call graph
    // node.  These edges might have been made irrelegant due to
    // optimization of the program.
    CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN);

    // Removing the node for callee from the call graph and delete it.
    FunctionsToRemove.push_back(CGN);
  }
  if (FunctionsToRemove.empty())
    return false;

  // Now that we know which functions to delete, do so.  We didn't want to do
  // this inline, because that would invalidate our CallGraph::iterator
  // objects. :(
  //
  // Note that it doesn't matter that we are iterating over a non-stable order
  // here to do this, it doesn't matter which order the functions are deleted
  // in.
  array_pod_sort(FunctionsToRemove.begin(), FunctionsToRemove.end());
  FunctionsToRemove.erase(std::unique(FunctionsToRemove.begin(),
                                      FunctionsToRemove.end()),
                          FunctionsToRemove.end());
  for (SmallVectorImpl<CallGraphNode *>::iterator I = FunctionsToRemove.begin(),
                                                  E = FunctionsToRemove.end();
       I != E; ++I) {
    delete CG.removeFunctionFromModule(*I);
    ++NumDeleted;
  }
  return true;
}
Exemplo n.º 2
0
Arquivo: Inliner.cpp Projeto: CPFL/guc
/// removeDeadFunctions - Remove dead functions that are not included in
/// DNR (Do Not Remove) list.
bool Inliner::removeDeadFunctions(CallGraph &CG, 
                                  SmallPtrSet<const Function *, 16> *DNR) {
  SmallPtrSet<CallGraphNode*, 16> FunctionsToRemove;

  // Scan for all of the functions, looking for ones that should now be removed
  // from the program.  Insert the dead ones in the FunctionsToRemove set.
  for (CallGraph::iterator I = CG.begin(), E = CG.end(); I != E; ++I) {
    CallGraphNode *CGN = I->second;
    if (CGN->getFunction() == 0)
      continue;
    
    Function *F = CGN->getFunction();
    
    // If the only remaining users of the function are dead constants, remove
    // them.
    F->removeDeadConstantUsers();

    if (DNR && DNR->count(F))
      continue;
    if (!F->hasLinkOnceLinkage() && !F->hasLocalLinkage() &&
        !F->hasAvailableExternallyLinkage())
      continue;
    if (!F->use_empty())
      continue;
    
    // Remove any call graph edges from the function to its callees.
    CGN->removeAllCalledFunctions();

    // Remove any edges from the external node to the function's call graph
    // node.  These edges might have been made irrelegant due to
    // optimization of the program.
    CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN);

    // Removing the node for callee from the call graph and delete it.
    FunctionsToRemove.insert(CGN);
  }

  // Now that we know which functions to delete, do so.  We didn't want to do
  // this inline, because that would invalidate our CallGraph::iterator
  // objects. :(
  //
  // Note that it doesn't matter that we are iterating over a non-stable set
  // here to do this, it doesn't matter which order the functions are deleted
  // in.
  bool Changed = false;
  for (SmallPtrSet<CallGraphNode*, 16>::iterator I = FunctionsToRemove.begin(),
       E = FunctionsToRemove.end(); I != E; ++I) {
    resetCachedCostInfo((*I)->getFunction());
    delete CG.removeFunctionFromModule(*I);
    ++NumDeleted;
    Changed = true;
  }

  return Changed;
}
Exemplo n.º 3
0
void AnalysisConsumer::HandleDeclsCallGraph(const unsigned LocalTUDeclsSize) {
  // Build the Call Graph by adding all the top level declarations to the graph.
  // Note: CallGraph can trigger deserialization of more items from a pch
  // (though HandleInterestingDecl); triggering additions to LocalTUDecls.
  // We rely on random access to add the initially processed Decls to CG.
  CallGraph CG;
  for (unsigned i = 0 ; i < LocalTUDeclsSize ; ++i) {
    CG.addToCallGraph(LocalTUDecls[i]);
  }

  // Walk over all of the call graph nodes in topological order, so that we
  // analyze parents before the children. Skip the functions inlined into
  // the previously processed functions. Use external Visited set to identify
  // inlined functions. The topological order allows the "do not reanalyze
  // previously inlined function" performance heuristic to be triggered more
  // often.
  SetOfConstDecls Visited;
  SetOfConstDecls VisitedAsTopLevel;
  llvm::ReversePostOrderTraversal<clang::CallGraph*> RPOT(&CG);
  for (llvm::ReversePostOrderTraversal<clang::CallGraph*>::rpo_iterator
         I = RPOT.begin(), E = RPOT.end(); I != E; ++I) {
    NumFunctionTopLevel++;
	
    CallGraphNode *N = *I;
    Decl *D = N->getDecl();
	string ssStart = D->getLocStart().printToString(Mgr->getASTContext().getSourceManager());

    // Skip the abstract root node.
    if (!D)
      continue;

    // Skip the functions which have been processed already or previously
    // inlined.
    if (shouldSkipFunction(D, Visited, VisitedAsTopLevel))
      continue;

    // Analyze the function.
    SetOfConstDecls VisitedCallees;

    HandleCode(D, AM_Path, 
               (Mgr->options.InliningMode == All ? nullptr : &VisitedCallees));

    // Add the visited callees to the global visited set.
    for (SetOfConstDecls::iterator I = VisitedCallees.begin(),
                                   E = VisitedCallees.end(); I != E; ++I) {
        Visited.insert(*I);
    }
    VisitedAsTopLevel.insert(D);
  }
}
Exemplo n.º 4
0
// FIXME: This code is stolen from CallGraph::addToCallGraph(Function *F), which
// happens to be private. It is better for this functionality exposed by the
// CallGraph.
static void buildCGN(CallGraph &CG, CallGraphNode *Node) {
  Function *F = Node->getFunction();

  // Look for calls by this function.
  for (Instruction &I : instructions(F))
    if (CallSite CS = CallSite(cast<Value>(&I))) {
      const Function *Callee = CS.getCalledFunction();
      if (!Callee || !Intrinsic::isLeaf(Callee->getIntrinsicID()))
        // Indirect calls of intrinsics are not allowed so no need to check.
        // We can be more precise here by using TargetArg returned by
        // Intrinsic::isLeaf.
        Node->addCalledFunction(CS, CG.getCallsExternalNode());
      else if (!Callee->isIntrinsic())
        Node->addCalledFunction(CS, CG.getOrInsertFunction(Callee));
    }
}
Exemplo n.º 5
0
// InlineCallIfPossible - If it is possible to inline the specified call site,
// do so and update the CallGraph for this operation.
static bool InlineCallIfPossible(CallSite CS, CallGraph &CG,
                                 const std::set<Function*> &SCCFunctions,
                                 const TargetData &TD) {
    Function *Callee = CS.getCalledFunction();
    Function *Caller = CS.getCaller();

    if (!InlineFunction(CS, &CG, &TD)) return false;

    // If the inlined function had a higher stack protection level than the
    // calling function, then bump up the caller's stack protection level.
    if (Callee->hasFnAttr(Attribute::StackProtectReq))
        Caller->addFnAttr(Attribute::StackProtectReq);
    else if (Callee->hasFnAttr(Attribute::StackProtect) &&
             !Caller->hasFnAttr(Attribute::StackProtectReq))
        Caller->addFnAttr(Attribute::StackProtect);

    // If we inlined the last possible call site to the function, delete the
    // function body now.
    if (Callee->use_empty() && Callee->hasLocalLinkage() &&
            !SCCFunctions.count(Callee)) {
        DOUT << "    -> Deleting dead function: " << Callee->getName() << "\n";
        CallGraphNode *CalleeNode = CG[Callee];

        // Remove any call graph edges from the callee to its callees.
        CalleeNode->removeAllCalledFunctions();

        // Removing the node for callee from the call graph and delete it.
        delete CG.removeFunctionFromModule(CalleeNode);
        ++NumDeleted;
    }
    return true;
}
Exemplo n.º 6
0
bool PrintCgTree::runOnModule(Module &M)
{
#if LLVM_VERSION_MAJOR == 3 && LLVM_VERSION_MINOR == 4
   CallGraph CG;
   CG.runOnModule(M);
   CallGraphNode* root = CG.getRoot();
#else
   CallGraph CG(M);
   Function* Main = M.getFunction("main");
   CallGraphNode* root = Main?CG[Main]:CG.getExternalCallingNode();
   
#endif
   Assert(root->getFunction()==Main, "");
   errs()<<root->getFunction()->getName()<<"\n";
   print_cg(root);
   return false;
}
Exemplo n.º 7
0
std::vector<Error> Recursivity::check(const super_ast::Block* ast,
                                std::vector<struct RecursivityCheck> checks) {
    FunctionIds fids;
    ast->Accept(fids);
    std::map<std::string, struct FunctionInfo> ids = fids.get_ids();

    CallGraph cg;
    cg.set_ids(ids);
    ast->Accept(cg);
    call_graph_ = cg.get_graph();
    call_count_ = cg.get_num_calls();

    call_count_.resize(call_graph_.size());
    std::vector<int> recursivity = get_recursivity();

    //for (int i = 0; i < call_graph_.size(); ++i) {
    //    std::cout << "[" << i << "] ";
    //    for (int j = 0; j < call_graph_[i].size(); ++j) {
    //        std::cout << " " << call_graph_[i][j];
    //    }
    //    std::cout << std::endl;
    //}

    //for (int i = 0; i < recursivity.size(); ++i) {
    //    std::cout << "[" << i << "] " << recursivity[i] << std::endl;
    //}

    //Error checking
    std::vector<Error> errors;
    for (struct RecursivityCheck c : checks) {
        struct FunctionInfo finf = ids[c.signature];
        if (c.depth != -1 and recursivity[finf.id] != c.depth) {
            // Error encountered 
            std::ostringstream ss;
            ss << "expected depth " << c.depth << " found " << recursivity[finf.id];
            std::string detail = ss.str();
            struct Error e(finf.line, c.signature, "RECURSIVITY ERROR",
                            detail);
            errors.push_back(e);
        }
    }
    return errors;
}
Exemplo n.º 8
0
// doInitialization - Initializes the vector of functions that have not 
// been annotated with the "always inline" attribute.
bool AlwaysInliner::doInitialization(CallGraph &CG) {
  Module &M = CG.getModule();
  
  for (Module::iterator I = M.begin(), E = M.end();
       I != E; ++I)
    if (!I->isDeclaration() && !I->hasFnAttr(Attribute::AlwaysInline))
      NeverInline.insert(I);

  return false;
}
Exemplo n.º 9
0
// doFinalization - Remove now-dead linkonce functions at the end of
// processing to avoid breaking the SCC traversal.
bool Inliner::doFinalization(CallGraph &CG) {
  std::set<CallGraphNode*> FunctionsToRemove;

  // Scan for all of the functions, looking for ones that should now be removed
  // from the program.  Insert the dead ones in the FunctionsToRemove set.
  for (CallGraph::iterator I = CG.begin(), E = CG.end(); I != E; ++I) {
    CallGraphNode *CGN = I->second;
    if (Function *F = CGN ? CGN->getFunction() : 0) {
      // If the only remaining users of the function are dead constants, remove
      // them.
      F->removeDeadConstantUsers();

      if ((F->hasLinkOnceLinkage() || F->hasInternalLinkage()) &&
          F->use_empty()) {

        // Remove any call graph edges from the function to its callees.
        while (!CGN->empty())
          CGN->removeCallEdgeTo((CGN->end()-1)->second);

        // Remove any edges from the external node to the function's call graph
        // node.  These edges might have been made irrelegant due to
        // optimization of the program.
        CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN);

        // Removing the node for callee from the call graph and delete it.
        FunctionsToRemove.insert(CGN);
      }
    }
  }

  // Now that we know which functions to delete, do so.  We didn't want to do
  // this inline, because that would invalidate our CallGraph::iterator
  // objects. :(
  bool Changed = false;
  for (std::set<CallGraphNode*>::iterator I = FunctionsToRemove.begin(),
         E = FunctionsToRemove.end(); I != E; ++I) {
    delete CG.removeFunctionFromModule(*I);
    ++NumDeleted;
    Changed = true;
  }

  return Changed;
}
Exemplo n.º 10
0
// Make sure that there is a devirtualization trigger function that CoroSplit
// pass uses the force restart CGSCC pipeline. If devirt trigger function is not
// found, we will create one and add it to the current SCC.
static void createDevirtTriggerFunc(CallGraph &CG, CallGraphSCC &SCC) {
  Module &M = CG.getModule();
  if (M.getFunction(CORO_DEVIRT_TRIGGER_FN))
    return;

  LLVMContext &C = M.getContext();
  auto *FnTy = FunctionType::get(Type::getVoidTy(C), Type::getInt8PtrTy(C),
                                 /*IsVarArgs=*/false);
  Function *DevirtFn =
      Function::Create(FnTy, GlobalValue::LinkageTypes::PrivateLinkage,
                       CORO_DEVIRT_TRIGGER_FN, &M);
  DevirtFn->addFnAttr(Attribute::AlwaysInline);
  auto *Entry = BasicBlock::Create(C, "entry", DevirtFn);
  ReturnInst::Create(C, Entry);

  auto *Node = CG.getOrInsertFunction(DevirtFn);

  SmallVector<CallGraphNode *, 8> Nodes(SCC.begin(), SCC.end());
  Nodes.push_back(Node);
  SCC.initialize(Nodes);
}
Exemplo n.º 11
0
void benchAnalyzingEdges(CallGraph& graph) {
    Infos infos;
    Analyzer analyzer(graph, infos);

    Timer timer;

    CallSiteIterator cit, cend;
    for (boost::tie(cit, cend) = graph.callSites(); cit != cend; ++cit) {
        analyzer.computeCallSiteTemperature(*cit);
    }

    analyzeEdges += timer.elapsed();
}
Exemplo n.º 12
0
void benchAnalyzingVertices(CallGraph& graph) {
    Infos infos;
    Analyzer analyzer(graph, infos);

    Timer timer;

    FunctionIterator fit, fend;
    for (boost::tie(fit, fend) = graph.functions(); fit != fend; ++fit) {
        analyzer.computeFunctionTemperature(*fit);
    }

    analyzeVertices += timer.elapsed();
}
Exemplo n.º 13
0
bool CallGraphCFG::runOnModule(Module &M) {
    CallGraph *CG = &getAnalysis<CallGraph>();
    CallGraphNode *root = CG->getRoot();
    if (root == NULL) return true;

    getDefectList(defectFile, &dl);
    if (dl.size()==0) return true;

    for (defectList::iterator dit=dl.begin(); dit != dl.end(); ++dit) {
        std::string file = dit->first;
        std::vector<int> lines = dit->second;
        for (std::vector<int>::iterator lit=lines.begin(); lit != lines.end(); ++lit) {
            std::cerr << "Mapping defect to BBs " << file << ":" << *lit << "\n";
            std::vector<BasicBlock*> tpath;
            findBBPath(root, tpath, file, *lit);
            if (tpath.size() == 0)
                std::cerr << "! unreachable " << file << ":" << *lit << "\n";
            else
                bbpaths->push_back(tpath);
        }
    }
    return false;
}
Exemplo n.º 14
0
void benchForeachEdges(const CallGraph& graph) {
    double sum = 0;

    Timer timer;

    CallSiteIterator first, last;
    for (boost::tie(first, last) = graph.callSites(); first != last; ++first) {
        sum += graph[*first].temperature;
    }

    foreachEdges += timer.elapsed();

    fakeSum += sum;
}
Exemplo n.º 15
0
/// Finalize CG
bool CGPassManager::doFinalization(CallGraph &CG) {
  bool Changed = false;
  for (unsigned Index = 0; Index < getNumContainedPasses(); ++Index) {  
    Pass *P = getContainedPass(Index);
    if (CallGraphSCCPass *CGSP = dynamic_cast<CallGraphSCCPass *>(P)) {
      Changed |= CGSP->doFinalization(CG);
    } else {
      FPPassManager *FP = dynamic_cast<FPPassManager *>(P);
      assert (FP && "Invalid CGPassManager member");
      Changed |= FP->doFinalization(CG.getModule());
    }
  }
  return Changed;
}
Exemplo n.º 16
0
pdvector<const resource*> MagnifyManager::getChildren(const resource *rh, 
						     magnifyType type) {

    pdvector<const resource*> ret;

    if(type == OriginalSearch) {
        ret = rh->getChildren();
    }
    else
    {
        assert(type == CallGraphSearch);

        //It doesn't make sense to expand the call graph down all of 
        //the resource hierarchies.
        if(!rh->MagnifyTypeApplies(type))
            ret = rh->getChildren(true);
        else{
            CallGraph* cg = CallGraph::FindCallGraph();
            assert(cg);
            ret = cg->getChildren(rh);
        }
    }
    return ret;
}
Exemplo n.º 17
0
// Rebuild CGN after we extracted parts of the code from ParentFunc into
// NewFuncs. Builds CGNs for the NewFuncs and adds them to the current SCC.
void coro::updateCallGraph(Function &ParentFunc, ArrayRef<Function *> NewFuncs,
                           CallGraph &CG, CallGraphSCC &SCC) {
  // Rebuild CGN from scratch for the ParentFunc
  auto *ParentNode = CG[&ParentFunc];
  ParentNode->removeAllCalledFunctions();
  buildCGN(CG, ParentNode);

  SmallVector<CallGraphNode *, 8> Nodes(SCC.begin(), SCC.end());

  for (Function *F : NewFuncs) {
    CallGraphNode *Callee = CG.getOrInsertFunction(F);
    Nodes.push_back(Callee);
    buildCGN(CG, Callee);
  }

  SCC.initialize(Nodes);
}
Exemplo n.º 18
0
// doInitialization - Initializes the vector of functions that have been
// annotated with the noinline attribute.
bool SimpleInliner::doInitialization(CallGraph &CG) {
  CA.setTargetData(getAnalysisIfAvailable<TargetData>());

  Module &M = CG.getModule();

  for (Module::iterator I = M.begin(), E = M.end();
       I != E; ++I)
    if (!I->isDeclaration() && I->hasFnAttr(Attribute::NoInline))
      NeverInline.insert(I);

  // Get llvm.noinline
  GlobalVariable *GV = M.getNamedGlobal("llvm.noinline");

  if (GV == 0)
    return false;

  // Don't crash on invalid code
  if (!GV->hasDefinitiveInitializer())
    return false;

  const ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());

  if (InitList == 0)
    return false;

  // Iterate over each element and add to the NeverInline set
  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {

    // Get Source
    const Constant *Elt = InitList->getOperand(i);

    if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(Elt))
      if (CE->getOpcode() == Instruction::BitCast)
        Elt = CE->getOperand(0);

    // Insert into set of functions to never inline
    if (const Function *F = dyn_cast<Function>(Elt))
      NeverInline.insert(F);
  }

  return false;
}
Exemplo n.º 19
0
// InlineCallIfPossible - If it is possible to inline the specified call site,
// do so and update the CallGraph for this operation.
static bool InlineCallIfPossible(CallSite CS, CallGraph &CG,
                                 const std::set<Function*> &SCCFunctions,
                                 const TargetData &TD) {
  Function *Callee = CS.getCalledFunction();
  if (!InlineFunction(CS, &CG, &TD)) return false;

  // If we inlined the last possible call site to the function, delete the
  // function body now.
  if (Callee->use_empty() && Callee->hasInternalLinkage() &&
      !SCCFunctions.count(Callee)) {
    DOUT << "    -> Deleting dead function: " << Callee->getName() << "\n";

    // Remove any call graph edges from the callee to its callees.
    CallGraphNode *CalleeNode = CG[Callee];
    while (!CalleeNode->empty())
      CalleeNode->removeCallEdgeTo((CalleeNode->end()-1)->second);

    // Removing the node for callee from the call graph and delete it.
    delete CG.removeFunctionFromModule(CalleeNode);
    ++NumDeleted;
  }
  return true;
}
Exemplo n.º 20
0
// When we see the coroutine the first time, we insert an indirect call to a
// devirt trigger function and mark the coroutine that it is now ready for
// split.
static void prepareForSplit(Function &F, CallGraph &CG) {
  Module &M = *F.getParent();
#ifndef NDEBUG
  Function *DevirtFn = M.getFunction(CORO_DEVIRT_TRIGGER_FN);
  assert(DevirtFn && "coro.devirt.trigger function not found");
#endif

  F.addFnAttr(CORO_PRESPLIT_ATTR, PREPARED_FOR_SPLIT);

  // Insert an indirect call sequence that will be devirtualized by CoroElide
  // pass:
  //    %0 = call i8* @llvm.coro.subfn.addr(i8* null, i8 -1)
  //    %1 = bitcast i8* %0 to void(i8*)*
  //    call void %1(i8* null)
  coro::LowererBase Lowerer(M);
  Instruction *InsertPt = F.getEntryBlock().getTerminator();
  auto *Null = ConstantPointerNull::get(Type::getInt8PtrTy(F.getContext()));
  auto *DevirtFnAddr =
      Lowerer.makeSubFnCall(Null, CoroSubFnInst::RestartTrigger, InsertPt);
  auto *IndirectCall = CallInst::Create(DevirtFnAddr, Null, "", InsertPt);

  // Update CG graph with an indirect call we just added.
  CG[&F]->addCalledFunction(IndirectCall, CG.getCallsExternalNode());
}
Exemplo n.º 21
0
bool InternalizePass::runOnModule(Module &M) {
  CallGraph *CG = getAnalysisIfAvailable<CallGraph>();
  CallGraphNode *ExternalNode = CG ? CG->getExternalCallingNode() : 0;
  
  if (ExternalNames.empty()) {
    // Return if we're not in 'all but main' mode and have no external api
    if (!AllButMain)
      return false;
    // If no list or file of symbols was specified, check to see if there is a
    // "main" symbol defined in the module.  If so, use it, otherwise do not
    // internalize the module, it must be a library or something.
    //
    Function *MainFunc = M.getFunction("main");
    if (MainFunc == 0 || MainFunc->isDeclaration())
      return false;  // No main found, must be a library...

    // Preserve main, internalize all else.
    ExternalNames.insert(MainFunc->getName());
  }

  bool Changed = false;

  // Never internalize functions which code-gen might insert.
  ExternalNames.insert("__stack_chk_fail");

  // Mark all functions not in the api as internal.
  // FIXME: maybe use private linkage?
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
    if (!I->isDeclaration() &&         // Function must be defined here
        // Available externally is really just a "declaration with a body".
        !I->hasAvailableExternallyLinkage() &&
        !I->hasLocalLinkage() &&  // Can't already have internal linkage
        !ExternalNames.count(I->getName())) {// Not marked to keep external?
      I->setLinkage(GlobalValue::InternalLinkage);
      // Remove a callgraph edge from the external node to this function.
      if (ExternalNode) ExternalNode->removeOneAbstractEdgeTo((*CG)[I]);
      Changed = true;
      ++NumFunctions;
      DEBUG(dbgs() << "Internalizing func " << I->getName() << "\n");
    }

  // Never internalize the llvm.used symbol.  It is used to implement
  // attribute((used)).
  // FIXME: Shouldn't this just filter on llvm.metadata section??
  ExternalNames.insert("llvm.used");
  ExternalNames.insert("llvm.compiler.used");

  // Never internalize anchors used by the machine module info, else the info
  // won't find them.  (see MachineModuleInfo.)
  ExternalNames.insert("llvm.global_ctors");
  ExternalNames.insert("llvm.global_dtors");
  ExternalNames.insert("llvm.global.annotations");

  // Never internalize symbols code-gen inserts.
  ExternalNames.insert("__stack_chk_guard");

  // Mark all global variables with initializers that are not in the api as
  // internal as well.
  // FIXME: maybe use private linkage?
  for (Module::global_iterator I = M.global_begin(), E = M.global_end();
       I != E; ++I)
    if (!I->isDeclaration() && !I->hasLocalLinkage() &&
        // Available externally is really just a "declaration with a body".
        !I->hasAvailableExternallyLinkage() &&
        !ExternalNames.count(I->getName())) {
      I->setLinkage(GlobalValue::InternalLinkage);
      Changed = true;
      ++NumGlobals;
      DEBUG(dbgs() << "Internalized gvar " << I->getName() << "\n");
    }

  // Mark all aliases that are not in the api as internal as well.
  for (Module::alias_iterator I = M.alias_begin(), E = M.alias_end();
       I != E; ++I)
    if (!I->isDeclaration() && !I->hasInternalLinkage() &&
        // Available externally is really just a "declaration with a body".
        !I->hasAvailableExternallyLinkage() &&
        !ExternalNames.count(I->getName())) {
      I->setLinkage(GlobalValue::InternalLinkage);
      Changed = true;
      ++NumAliases;
      DEBUG(dbgs() << "Internalized alias " << I->getName() << "\n");
    }

  return Changed;
}
Exemplo n.º 22
0
/// Remove dead functions that are not included in DNR (Do Not Remove) list.
bool Inliner::removeDeadFunctions(CallGraph &CG, bool AlwaysInlineOnly) {
  SmallVector<CallGraphNode*, 16> FunctionsToRemove;
  SmallVector<CallGraphNode *, 16> DeadFunctionsInComdats;
  SmallDenseMap<const Comdat *, int, 16> ComdatEntriesAlive;

  auto RemoveCGN = [&](CallGraphNode *CGN) {
    // Remove any call graph edges from the function to its callees.
    CGN->removeAllCalledFunctions();

    // Remove any edges from the external node to the function's call graph
    // node.  These edges might have been made irrelegant due to
    // optimization of the program.
    CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN);

    // Removing the node for callee from the call graph and delete it.
    FunctionsToRemove.push_back(CGN);
  };

  // Scan for all of the functions, looking for ones that should now be removed
  // from the program.  Insert the dead ones in the FunctionsToRemove set.
  for (CallGraph::iterator I = CG.begin(), E = CG.end(); I != E; ++I) {
    CallGraphNode *CGN = I->second;
    Function *F = CGN->getFunction();
    if (!F || F->isDeclaration())
      continue;

    // Handle the case when this function is called and we only want to care
    // about always-inline functions. This is a bit of a hack to share code
    // between here and the InlineAlways pass.
    if (AlwaysInlineOnly && !F->hasFnAttribute(Attribute::AlwaysInline))
      continue;

    // If the only remaining users of the function are dead constants, remove
    // them.
    F->removeDeadConstantUsers();

    if (!F->isDefTriviallyDead())
      continue;

    // It is unsafe to drop a function with discardable linkage from a COMDAT
    // without also dropping the other members of the COMDAT.
    // The inliner doesn't visit non-function entities which are in COMDAT
    // groups so it is unsafe to do so *unless* the linkage is local.
    if (!F->hasLocalLinkage()) {
      if (const Comdat *C = F->getComdat()) {
        --ComdatEntriesAlive[C];
        DeadFunctionsInComdats.push_back(CGN);
        continue;
      }
    }

    RemoveCGN(CGN);
  }
  if (!DeadFunctionsInComdats.empty()) {
    // Count up all the entities in COMDAT groups
    auto ComdatGroupReferenced = [&](const Comdat *C) {
      auto I = ComdatEntriesAlive.find(C);
      if (I != ComdatEntriesAlive.end())
        ++(I->getSecond());
    };
    for (const Function &F : CG.getModule())
      if (const Comdat *C = F.getComdat())
        ComdatGroupReferenced(C);
    for (const GlobalVariable &GV : CG.getModule().globals())
      if (const Comdat *C = GV.getComdat())
        ComdatGroupReferenced(C);
    for (const GlobalAlias &GA : CG.getModule().aliases())
      if (const Comdat *C = GA.getComdat())
        ComdatGroupReferenced(C);
    for (CallGraphNode *CGN : DeadFunctionsInComdats) {
      Function *F = CGN->getFunction();
      const Comdat *C = F->getComdat();
      int NumAlive = ComdatEntriesAlive[C];
      // We can remove functions in a COMDAT group if the entire group is dead.
      assert(NumAlive >= 0);
      if (NumAlive > 0)
        continue;

      RemoveCGN(CGN);
    }
  }

  if (FunctionsToRemove.empty())
    return false;

  // Now that we know which functions to delete, do so.  We didn't want to do
  // this inline, because that would invalidate our CallGraph::iterator
  // objects. :(
  //
  // Note that it doesn't matter that we are iterating over a non-stable order
  // here to do this, it doesn't matter which order the functions are deleted
  // in.
  array_pod_sort(FunctionsToRemove.begin(), FunctionsToRemove.end());
  FunctionsToRemove.erase(std::unique(FunctionsToRemove.begin(),
                                      FunctionsToRemove.end()),
                          FunctionsToRemove.end());
  for (SmallVectorImpl<CallGraphNode *>::iterator I = FunctionsToRemove.begin(),
                                                  E = FunctionsToRemove.end();
       I != E; ++I) {
    delete CG.removeFunctionFromModule(*I);
    ++NumDeleted;
  }
  return true;
}
Exemplo n.º 23
0
bool LegacyInlinerBase::doInitialization(CallGraph &CG) {
  if (InlinerFunctionImportStats != InlinerFunctionImportStatsOpts::No)
    ImportedFunctionsStats.setModuleInfo(CG.getModule());
  return false; // No changes to CallGraph.
}
Exemplo n.º 24
0
static bool
inlineCallsImpl(CallGraphSCC &SCC, CallGraph &CG,
                std::function<AssumptionCache &(Function &)> GetAssumptionCache,
                ProfileSummaryInfo *PSI, TargetLibraryInfo &TLI,
                bool InsertLifetime,
                function_ref<InlineCost(CallSite CS)> GetInlineCost,
                function_ref<AAResults &(Function &)> AARGetter,
                ImportedFunctionsInliningStatistics &ImportedFunctionsStats) {
  SmallPtrSet<Function *, 8> SCCFunctions;
  LLVM_DEBUG(dbgs() << "Inliner visiting SCC:");
  for (CallGraphNode *Node : SCC) {
    Function *F = Node->getFunction();
    if (F)
      SCCFunctions.insert(F);
    LLVM_DEBUG(dbgs() << " " << (F ? F->getName() : "INDIRECTNODE"));
  }

  // Scan through and identify all call sites ahead of time so that we only
  // inline call sites in the original functions, not call sites that result
  // from inlining other functions.
  SmallVector<std::pair<CallSite, int>, 16> CallSites;

  // When inlining a callee produces new call sites, we want to keep track of
  // the fact that they were inlined from the callee.  This allows us to avoid
  // infinite inlining in some obscure cases.  To represent this, we use an
  // index into the InlineHistory vector.
  SmallVector<std::pair<Function *, int>, 8> InlineHistory;

  for (CallGraphNode *Node : SCC) {
    Function *F = Node->getFunction();
    if (!F || F->isDeclaration())
      continue;

    OptimizationRemarkEmitter ORE(F);
    for (BasicBlock &BB : *F)
      for (Instruction &I : BB) {
        CallSite CS(cast<Value>(&I));
        // If this isn't a call, or it is a call to an intrinsic, it can
        // never be inlined.
        if (!CS || isa<IntrinsicInst>(I))
          continue;

        // If this is a direct call to an external function, we can never inline
        // it.  If it is an indirect call, inlining may resolve it to be a
        // direct call, so we keep it.
        if (Function *Callee = CS.getCalledFunction())
          if (Callee->isDeclaration()) {
            using namespace ore;

            ORE.emit([&]() {
              return OptimizationRemarkMissed(DEBUG_TYPE, "NoDefinition", &I)
                     << NV("Callee", Callee) << " will not be inlined into "
                     << NV("Caller", CS.getCaller())
                     << " because its definition is unavailable"
                     << setIsVerbose();
            });
            continue;
          }

        CallSites.push_back(std::make_pair(CS, -1));
      }
  }

  LLVM_DEBUG(dbgs() << ": " << CallSites.size() << " call sites.\n");

  // If there are no calls in this function, exit early.
  if (CallSites.empty())
    return false;

  // Now that we have all of the call sites, move the ones to functions in the
  // current SCC to the end of the list.
  unsigned FirstCallInSCC = CallSites.size();
  for (unsigned i = 0; i < FirstCallInSCC; ++i)
    if (Function *F = CallSites[i].first.getCalledFunction())
      if (SCCFunctions.count(F))
        std::swap(CallSites[i--], CallSites[--FirstCallInSCC]);

  InlinedArrayAllocasTy InlinedArrayAllocas;
  InlineFunctionInfo InlineInfo(&CG, &GetAssumptionCache, PSI);

  // Now that we have all of the call sites, loop over them and inline them if
  // it looks profitable to do so.
  bool Changed = false;
  bool LocalChange;
  do {
    LocalChange = false;
    // Iterate over the outer loop because inlining functions can cause indirect
    // calls to become direct calls.
    // CallSites may be modified inside so ranged for loop can not be used.
    for (unsigned CSi = 0; CSi != CallSites.size(); ++CSi) {
      CallSite CS = CallSites[CSi].first;

      Function *Caller = CS.getCaller();
      Function *Callee = CS.getCalledFunction();

      // We can only inline direct calls to non-declarations.
      if (!Callee || Callee->isDeclaration())
        continue;

      Instruction *Instr = CS.getInstruction();

      bool IsTriviallyDead = isInstructionTriviallyDead(Instr, &TLI);

      int InlineHistoryID;
      if (!IsTriviallyDead) {
        // If this call site was obtained by inlining another function, verify
        // that the include path for the function did not include the callee
        // itself.  If so, we'd be recursively inlining the same function,
        // which would provide the same callsites, which would cause us to
        // infinitely inline.
        InlineHistoryID = CallSites[CSi].second;
        if (InlineHistoryID != -1 &&
            InlineHistoryIncludes(Callee, InlineHistoryID, InlineHistory))
          continue;
      }

      // FIXME for new PM: because of the old PM we currently generate ORE and
      // in turn BFI on demand.  With the new PM, the ORE dependency should
      // just become a regular analysis dependency.
      OptimizationRemarkEmitter ORE(Caller);

      Optional<InlineCost> OIC = shouldInline(CS, GetInlineCost, ORE);
      // If the policy determines that we should inline this function,
      // delete the call instead.
      if (!OIC)
        continue;

      // If this call site is dead and it is to a readonly function, we should
      // just delete the call instead of trying to inline it, regardless of
      // size.  This happens because IPSCCP propagates the result out of the
      // call and then we're left with the dead call.
      if (IsTriviallyDead) {
        LLVM_DEBUG(dbgs() << "    -> Deleting dead call: " << *Instr << "\n");
        // Update the call graph by deleting the edge from Callee to Caller.
        CG[Caller]->removeCallEdgeFor(CS);
        Instr->eraseFromParent();
        ++NumCallsDeleted;
      } else {
        // Get DebugLoc to report. CS will be invalid after Inliner.
        DebugLoc DLoc = CS->getDebugLoc();
        BasicBlock *Block = CS.getParent();

        // Attempt to inline the function.
        using namespace ore;

        if (!InlineCallIfPossible(CS, InlineInfo, InlinedArrayAllocas,
                                  InlineHistoryID, InsertLifetime, AARGetter,
                                  ImportedFunctionsStats)) {
          ORE.emit([&]() {
            return OptimizationRemarkMissed(DEBUG_TYPE, "NotInlined", DLoc,
                                            Block)
                   << NV("Callee", Callee) << " will not be inlined into "
                   << NV("Caller", Caller);
          });
          continue;
        }
        ++NumInlined;

        ORE.emit([&]() {
          bool AlwaysInline = OIC->isAlways();
          StringRef RemarkName = AlwaysInline ? "AlwaysInline" : "Inlined";
          OptimizationRemark R(DEBUG_TYPE, RemarkName, DLoc, Block);
          R << NV("Callee", Callee) << " inlined into ";
          R << NV("Caller", Caller);
          if (AlwaysInline)
            R << " with cost=always";
          else {
            R << " with cost=" << NV("Cost", OIC->getCost());
            R << " (threshold=" << NV("Threshold", OIC->getThreshold());
            R << ")";
          }
          return R;
        });

        // If inlining this function gave us any new call sites, throw them
        // onto our worklist to process.  They are useful inline candidates.
        if (!InlineInfo.InlinedCalls.empty()) {
          // Create a new inline history entry for this, so that we remember
          // that these new callsites came about due to inlining Callee.
          int NewHistoryID = InlineHistory.size();
          InlineHistory.push_back(std::make_pair(Callee, InlineHistoryID));

          for (Value *Ptr : InlineInfo.InlinedCalls)
            CallSites.push_back(std::make_pair(CallSite(Ptr), NewHistoryID));
        }
      }

      // If we inlined or deleted the last possible call site to the function,
      // delete the function body now.
      if (Callee && Callee->use_empty() && Callee->hasLocalLinkage() &&
          // TODO: Can remove if in SCC now.
          !SCCFunctions.count(Callee) &&
          // The function may be apparently dead, but if there are indirect
          // callgraph references to the node, we cannot delete it yet, this
          // could invalidate the CGSCC iterator.
          CG[Callee]->getNumReferences() == 0) {
        LLVM_DEBUG(dbgs() << "    -> Deleting dead function: "
                          << Callee->getName() << "\n");
        CallGraphNode *CalleeNode = CG[Callee];

        // Remove any call graph edges from the callee to its callees.
        CalleeNode->removeAllCalledFunctions();

        // Removing the node for callee from the call graph and delete it.
        delete CG.removeFunctionFromModule(CalleeNode);
        ++NumDeleted;
      }

      // Remove this call site from the list.  If possible, use
      // swap/pop_back for efficiency, but do not use it if doing so would
      // move a call site to a function in this SCC before the
      // 'FirstCallInSCC' barrier.
      if (SCC.isSingular()) {
        CallSites[CSi] = CallSites.back();
        CallSites.pop_back();
      } else {
        CallSites.erase(CallSites.begin() + CSi);
      }
      --CSi;

      Changed = true;
      LocalChange = true;
    }
  } while (LocalChange);

  return Changed;
}
Exemplo n.º 25
0
bool ArgPromotion::doInitialization(CallGraph &CG) {
  FunctionDIs = makeSubprogramMap(CG.getModule());
  return CallGraphSCCPass::doInitialization(CG);
}
Exemplo n.º 26
0
/// Remove dead functions that are not included in DNR (Do Not Remove) list.
bool LegacyInlinerBase::removeDeadFunctions(CallGraph &CG,
                                            bool AlwaysInlineOnly) {
  SmallVector<CallGraphNode *, 16> FunctionsToRemove;
  SmallVector<Function *, 16> DeadFunctionsInComdats;

  auto RemoveCGN = [&](CallGraphNode *CGN) {
    // Remove any call graph edges from the function to its callees.
    CGN->removeAllCalledFunctions();

    // Remove any edges from the external node to the function's call graph
    // node.  These edges might have been made irrelegant due to
    // optimization of the program.
    CG.getExternalCallingNode()->removeAnyCallEdgeTo(CGN);

    // Removing the node for callee from the call graph and delete it.
    FunctionsToRemove.push_back(CGN);
  };

  // Scan for all of the functions, looking for ones that should now be removed
  // from the program.  Insert the dead ones in the FunctionsToRemove set.
  for (const auto &I : CG) {
    CallGraphNode *CGN = I.second.get();
    Function *F = CGN->getFunction();
    if (!F || F->isDeclaration())
      continue;

    // Handle the case when this function is called and we only want to care
    // about always-inline functions. This is a bit of a hack to share code
    // between here and the InlineAlways pass.
    if (AlwaysInlineOnly && !F->hasFnAttribute(Attribute::AlwaysInline))
      continue;

    // If the only remaining users of the function are dead constants, remove
    // them.
    F->removeDeadConstantUsers();

    if (!F->isDefTriviallyDead())
      continue;

    // It is unsafe to drop a function with discardable linkage from a COMDAT
    // without also dropping the other members of the COMDAT.
    // The inliner doesn't visit non-function entities which are in COMDAT
    // groups so it is unsafe to do so *unless* the linkage is local.
    if (!F->hasLocalLinkage()) {
      if (F->hasComdat()) {
        DeadFunctionsInComdats.push_back(F);
        continue;
      }
    }

    RemoveCGN(CGN);
  }
  if (!DeadFunctionsInComdats.empty()) {
    // Filter out the functions whose comdats remain alive.
    filterDeadComdatFunctions(CG.getModule(), DeadFunctionsInComdats);
    // Remove the rest.
    for (Function *F : DeadFunctionsInComdats)
      RemoveCGN(CG[F]);
  }

  if (FunctionsToRemove.empty())
    return false;

  // Now that we know which functions to delete, do so.  We didn't want to do
  // this inline, because that would invalidate our CallGraph::iterator
  // objects. :(
  //
  // Note that it doesn't matter that we are iterating over a non-stable order
  // here to do this, it doesn't matter which order the functions are deleted
  // in.
  array_pod_sort(FunctionsToRemove.begin(), FunctionsToRemove.end());
  FunctionsToRemove.erase(
      std::unique(FunctionsToRemove.begin(), FunctionsToRemove.end()),
      FunctionsToRemove.end());
  for (CallGraphNode *CGN : FunctionsToRemove) {
    delete CG.removeFunctionFromModule(CGN);
    ++NumDeleted;
  }
  return true;
}
Exemplo n.º 27
0
bool CGPassManager::RunPassOnSCC(Pass *P, CallGraphSCC &CurSCC,
                                 CallGraph &CG, bool &CallGraphUpToDate,
                                 bool &DevirtualizedCall) {
  bool Changed = false;
  PMDataManager *PM = P->getAsPMDataManager();
  Module &M = CG.getModule();

  if (!PM) {
    CallGraphSCCPass *CGSP = (CallGraphSCCPass *)P;
    if (!CallGraphUpToDate) {
      DevirtualizedCall |= RefreshCallGraph(CurSCC, CG, false);
      CallGraphUpToDate = true;
    }

    {
      unsigned InstrCount, SCCCount = 0;
      bool EmitICRemark = M.shouldEmitInstrCountChangedRemark();
      TimeRegion PassTimer(getPassTimer(CGSP));
      if (EmitICRemark)
        InstrCount = initSizeRemarkInfo(M);
      Changed = CGSP->runOnSCC(CurSCC);

      if (EmitICRemark) {
        // FIXME: Add getInstructionCount to CallGraphSCC.
        SCCCount = M.getInstructionCount();
        // Is there a difference in the number of instructions in the module?
        if (SCCCount != InstrCount) {
          // Yep. Emit a remark and update InstrCount.
          int64_t Delta =
              static_cast<int64_t>(SCCCount) - static_cast<int64_t>(InstrCount);
          emitInstrCountChangedRemark(P, M, Delta, InstrCount);
          InstrCount = SCCCount;
        }
      }
    }

    // After the CGSCCPass is done, when assertions are enabled, use
    // RefreshCallGraph to verify that the callgraph was correctly updated.
#ifndef NDEBUG
    if (Changed)
      RefreshCallGraph(CurSCC, CG, true);
#endif

    return Changed;
  }

  assert(PM->getPassManagerType() == PMT_FunctionPassManager &&
         "Invalid CGPassManager member");
  FPPassManager *FPP = (FPPassManager*)P;

  // Run pass P on all functions in the current SCC.
  for (CallGraphNode *CGN : CurSCC) {
    if (Function *F = CGN->getFunction()) {
      dumpPassInfo(P, EXECUTION_MSG, ON_FUNCTION_MSG, F->getName());
      {
        TimeRegion PassTimer(getPassTimer(FPP));
        Changed |= FPP->runOnFunction(*F);
      }
      F->getContext().yield();
    }
  }

  // The function pass(es) modified the IR, they may have clobbered the
  // callgraph.
  if (Changed && CallGraphUpToDate) {
    LLVM_DEBUG(dbgs() << "CGSCCPASSMGR: Pass Dirtied SCC: " << P->getPassName()
                      << '\n');
    CallGraphUpToDate = false;
  }
  return Changed;
}
Exemplo n.º 28
0
bool InternalizePass::runOnModule(Module &M) {
  CallGraph *CG = getAnalysisIfAvailable<CallGraph>();
  CallGraphNode *ExternalNode = CG ? CG->getExternalCallingNode() : 0;
  bool Changed = false;

  // Never internalize functions which code-gen might insert.
  // FIXME: We should probably add this (and the __stack_chk_guard) via some
  // type of call-back in CodeGen.
  ExternalNames.insert("__stack_chk_fail");

  // Mark all functions not in the api as internal.
  // FIXME: maybe use private linkage?
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I)
    if (!I->isDeclaration() &&         // Function must be defined here
        // Available externally is really just a "declaration with a body".
        !I->hasAvailableExternallyLinkage() &&
        !I->hasLocalLinkage() &&  // Can't already have internal linkage
        !ExternalNames.count(I->getName())) {// Not marked to keep external?
      I->setLinkage(GlobalValue::InternalLinkage);
      // Remove a callgraph edge from the external node to this function.
      if (ExternalNode) ExternalNode->removeOneAbstractEdgeTo((*CG)[I]);
      Changed = true;
      ++NumFunctions;
      DEBUG(dbgs() << "Internalizing func " << I->getName() << "\n");
    }

  // Never internalize the llvm.used symbol.  It is used to implement
  // attribute((used)).
  // FIXME: Shouldn't this just filter on llvm.metadata section??
  ExternalNames.insert("llvm.used");
  ExternalNames.insert("llvm.compiler.used");

  // Never internalize anchors used by the machine module info, else the info
  // won't find them.  (see MachineModuleInfo.)
  ExternalNames.insert("llvm.global_ctors");
  ExternalNames.insert("llvm.global_dtors");
  ExternalNames.insert("llvm.global.annotations");

  // Never internalize symbols code-gen inserts.
  ExternalNames.insert("__stack_chk_guard");

  // Mark all global variables with initializers that are not in the api as
  // internal as well.
  // FIXME: maybe use private linkage?
  for (Module::global_iterator I = M.global_begin(), E = M.global_end();
       I != E; ++I)
    if (!I->isDeclaration() && !I->hasLocalLinkage() &&
        // Available externally is really just a "declaration with a body".
        !I->hasAvailableExternallyLinkage() &&
        !ExternalNames.count(I->getName())) {
      I->setLinkage(GlobalValue::InternalLinkage);
      Changed = true;
      ++NumGlobals;
      DEBUG(dbgs() << "Internalized gvar " << I->getName() << "\n");
    }

  // Mark all aliases that are not in the api as internal as well.
  for (Module::alias_iterator I = M.alias_begin(), E = M.alias_end();
       I != E; ++I)
    if (!I->isDeclaration() && !I->hasInternalLinkage() &&
        // Available externally is really just a "declaration with a body".
        !I->hasAvailableExternallyLinkage() &&
        !ExternalNames.count(I->getName())) {
      I->setLinkage(GlobalValue::InternalLinkage);
      Changed = true;
      ++NumAliases;
      DEBUG(dbgs() << "Internalized alias " << I->getName() << "\n");
    }

  return Changed;
}
Exemplo n.º 29
0
bool InternalizePass::runOnModule(Module &M) {
  CallGraphWrapperPass *CGPass = getAnalysisIfAvailable<CallGraphWrapperPass>();
  CallGraph *CG = CGPass ? &CGPass->getCallGraph() : 0;
  CallGraphNode *ExternalNode = CG ? CG->getExternalCallingNode() : 0;
  bool Changed = false;

  SmallPtrSet<GlobalValue *, 8> Used;
  collectUsedGlobalVariables(M, Used, false);

  // We must assume that globals in llvm.used have a reference that not even
  // the linker can see, so we don't internalize them.
  // For llvm.compiler.used the situation is a bit fuzzy. The assembler and
  // linker can drop those symbols. If this pass is running as part of LTO,
  // one might think that it could just drop llvm.compiler.used. The problem
  // is that even in LTO llvm doesn't see every reference. For example,
  // we don't see references from function local inline assembly. To be
  // conservative, we internalize symbols in llvm.compiler.used, but we
  // keep llvm.compiler.used so that the symbol is not deleted by llvm.
  for (SmallPtrSet<GlobalValue *, 8>::iterator I = Used.begin(), E = Used.end();
       I != E; ++I) {
    GlobalValue *V = *I;
    ExternalNames.insert(V->getName());
  }

  // Mark all functions not in the api as internal.
  for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
    if (!shouldInternalize(*I, ExternalNames, OnlyHidden))
      continue;

    I->setLinkage(GlobalValue::InternalLinkage);

    if (ExternalNode)
      // Remove a callgraph edge from the external node to this function.
      ExternalNode->removeOneAbstractEdgeTo((*CG)[I]);

    Changed = true;
    ++NumFunctions;
    DEBUG(dbgs() << "Internalizing func " << I->getName() << "\n");
  }

  // Never internalize the llvm.used symbol.  It is used to implement
  // attribute((used)).
  // FIXME: Shouldn't this just filter on llvm.metadata section??
  ExternalNames.insert("llvm.used");
  ExternalNames.insert("llvm.compiler.used");

  // Never internalize anchors used by the machine module info, else the info
  // won't find them.  (see MachineModuleInfo.)
  ExternalNames.insert("llvm.global_ctors");
  ExternalNames.insert("llvm.global_dtors");
  ExternalNames.insert("llvm.global.annotations");

  // Never internalize symbols code-gen inserts.
  // FIXME: We should probably add this (and the __stack_chk_guard) via some
  // type of call-back in CodeGen.
  ExternalNames.insert("__stack_chk_fail");
  ExternalNames.insert("__stack_chk_guard");

  // Mark all global variables with initializers that are not in the api as
  // internal as well.
  for (Module::global_iterator I = M.global_begin(), E = M.global_end();
       I != E; ++I) {
    if (!shouldInternalize(*I, ExternalNames, OnlyHidden))
      continue;

    I->setLinkage(GlobalValue::InternalLinkage);
    Changed = true;
    ++NumGlobals;
    DEBUG(dbgs() << "Internalized gvar " << I->getName() << "\n");
  }

  // Mark all aliases that are not in the api as internal as well.
  for (Module::alias_iterator I = M.alias_begin(), E = M.alias_end();
       I != E; ++I) {
    if (!shouldInternalize(*I, ExternalNames, OnlyHidden))
      continue;

    I->setLinkage(GlobalValue::InternalLinkage);
    Changed = true;
    ++NumAliases;
    DEBUG(dbgs() << "Internalized alias " << I->getName() << "\n");
  }

  return Changed;
}
int main(int argc, const char* argv[]) {
    if (argc < 2) {
        cout << "Not enough arguments. Provide at least the dot file to read" << endl;

        return 1;
    }

    Parameters::init();

    Infos infos;
    GraphReader reader(infos);
    CallGraph* graph = reader.read(argv[1]);

    ofstream stream;
    stream.open("main.cpp");

    stream << "//Auto generated by inlining analyzer" << endl;
    stream << "#include <iostream>" << endl << endl;

    stream << "using std::cout;" << endl;
    stream << "using std::endl;" << endl << endl;

    string mainFunction = "";

    //Print the declarations
    FunctionIterator first, last;
    for (boost::tie(first, last) = graph->functions(); first != last; ++first) {
        string name = (*graph)[*first].name;

        transform(name);

        if (filter(name)) {
            continue;
        }

        if ((*graph)[*first].calls == 0) {
            mainFunction = name;
        }

        //Declaration
        stream << "void FFF" << name << "() __attribute__ ((noinline));" << endl;
    }

    //Print the definitions
    for (boost::tie(first, last) = graph->functions(); first != last; ++first) {
        string name = (*graph)[*first].name;

        transform(name);

        if (filter(name)) {
            continue;
        }

        //Definition
        stream << "void FFF" << name << "() {" << endl;
        stream << "\tcout << \"I'm in " << name << "\" << endl;" << endl;

        OutCallSiteIterator it, end;
        for (boost::tie(it, end) = boost::out_edges(*first, *graph->getGraph()); it != end; ++it) {
            string called = (*graph)[boost::target(*it, *graph->getGraph())].name;

            transform(called);

            if (filter(called)) {
                continue;
            }

            stream << "\tFFF" << called << "();" << endl;
        }

        stream << "}" << endl << endl;
    }

    //Write main function
    stream << "int main(){" << endl;
    stream << "\tcout << \"I'm in main()\" << endl;" << endl;
    stream << "\tFFF" << mainFunction << "();" << endl;
    stream << "\treturn 0;" << endl;
    stream << "}" << endl;

    stream.close();

    delete graph;

    return 0;
}