C++ DSGraph::node_end方法代码示例

//
// Method: getLocalPoolNodes()
//
// Description:
//  For a given function, determine which DSNodes for that function should have
//  local pools created for them.
//
void
Heuristic::getLocalPoolNodes (const Function & F, DSNodeList_t & Nodes) {
  //
  // Get the DSGraph of the specified function.  If the DSGraph has no nodes,
  // then there is nothing we need to do.
  //
  DSGraph* G = Graphs->getDSGraph(F);
  if (G->node_begin() == G->node_end()) return;

  //
  // Calculate which DSNodes are reachable from globals.  If a node is reachable
  // from a global, we will create a global pool for it, so no argument passage
  // is required.
  Graphs->getGlobalsGraph();

  // Map all node reachable from this global to the corresponding nodes in
  // the globals graph.
  DSGraph::NodeMapTy GlobalsGraphNodeMapping;
  G->computeGToGGMapping(GlobalsGraphNodeMapping);

  //
  // Loop over all of the nodes which are non-escaping, adding pool-allocatable
  // ones to the NodesToPA vector.  In other words, scan over the DSGraph and
  // find nodes for which a new pool must be created within this function.
  //
  for (DSGraph::node_iterator I = G->node_begin(), E = G->node_end();
       I != E;
       ++I){
    // Get the DSNode and, if applicable, its mirror in the globals graph
    DSNode * N   = I;
    DSNode * GGN = GlobalsGraphNodeMapping[N].getNode();

    //
    // Only the following nodes are pool allocated:
    //  1) Local Heap nodes
    //  2) Nodes which are mirrored in the globals graph and, in the globals
    //     graph, are heap nodes.
    //
    if ((N->isHeapNode()) || (GGN && GGN->isHeapNode())) {
      if (!(GlobalPoolNodes.count (N) || GlobalPoolNodes.count (GGN))) {
        // Otherwise, if it was not passed in from outside the function, it must
        // be a local pool!
        assert((!N->isGlobalNode() || N->isPtrToIntNode()) && "Should be in global mapping!");
        if(!N->isPtrToIntNode()) {
          Nodes.push_back (N);
        }
      }
    }
  }

  return;
}

//
// Method: findGlobalPoolNodes()
//
// Description:
//  This method finds DSNodes that are reachable from globals and that need a
//  pool.  The Automatic Pool Allocation transform will use the returned
//  information to build global pools for the DSNodes in question.
//
//  Note that this method does not assign DSNodes to pools; it merely decides
//  which DSNodes are reachable from globals and will need a pool of global
//  scope.
//
// Outputs:
//  Nodes - The DSNodes that are both reachable from globals and which should
//          have global pools will be *added* to this container.
//
void
AllHeapNodesHeuristic::findGlobalPoolNodes (DSNodeSet_t & Nodes) {
  // Get the globals graph for the program.
  DSGraph* GG = Graphs->getGlobalsGraph();

  // Get all of the nodes reachable from globals.
  DenseSet<const DSNode*> GlobalHeapNodes;
  GetNodesReachableFromGlobals (GG, GlobalHeapNodes);
  //
  // Create a global pool for each global DSNode.
  //
  for (DenseSet<const DSNode *>::iterator NI = GlobalHeapNodes.begin();
              NI != GlobalHeapNodes.end();++NI) {
    const DSNode * N = *NI;
    PoolMap[N] = OnePool(N);
  }

  //
  // Now find all DSNodes belonging to function-local DSGraphs which are
  // mirrored in the globals graph.  These DSNodes require a global pool, too.
  //
  for (Module::iterator F = M->begin(); F != M->end(); ++F) {
    if (Graphs->hasDSGraph(*F)) {
      DSGraph* G = Graphs->getDSGraph(*F);
      DSGraph::NodeMapTy NodeMap;
      G->computeGToGGMapping (NodeMap);
      //
      // Scan through all DSNodes in the local graph.  If a local DSNode has a
      // corresponding DSNode in the globals graph that is reachable from a 
      // global, then add the local DSNode to the set of DSNodes reachable from
      // a global.
      //
      DSGraph::node_iterator ni = G->node_begin();
      for (; ni != G->node_end(); ++ni) {
        DSNode * N = ni;
        DSNode * GGN = NodeMap[N].getNode();
        
        //assert (!GGN || GlobalHeapNodes.count (GGN));
        if (GGN && GlobalHeapNodes.count (GGN))
          PoolMap[GGN].NodesInPool.push_back (N);
      }
    }
  }

  //
  // Copy the values into the output container.  Note that DenseSet has no
  // iterator traits (or whatever allows us to treat DenseSet has a generic
  // container), so we have to use a loop to copy values from the DenseSet into
  // the output container.
  //
  for (DenseSet<const DSNode*>::iterator I = GlobalHeapNodes.begin(),
         E = GlobalHeapNodes.end(); I != E; ++I) {
    Nodes.insert (*I);
  }

  return;
}

//
// Function: GetNodesReachableFromGlobals()
//
// Description:
//  This function finds all DSNodes which are reachable from globals.  It finds
//  DSNodes both within the local DSGraph as well as in the Globals graph that
//  are reachable from globals.
//
// Inputs:
//  G - The Globals Graph.
//
// Outputs:
//  NodesFromGlobals - A reference to a container object in which to record
//                     DSNodes reachable from globals.  DSNodes are *added* to
//                     this container; it is not cleared by this function.
//                     DSNodes from both the local and globals graph are added.
static void
GetNodesReachableFromGlobals (DSGraph* G,
                              DenseSet<const DSNode*> &NodesFromGlobals) {
    //
    // Ensure that G is the globals graph.
    //
    assert (G->getGlobalsGraph() == 0);
    DSGraph * GlobalsGraph = G;

    //
    // Find all DSNodes which are reachable in the globals graph.
    //
    for (DSGraph::node_iterator NI = GlobalsGraph->node_begin();
            NI != GlobalsGraph->node_end();
            ++NI) {
        NI->markReachableNodes(NodesFromGlobals);
    }
}

// Get all nodes in all function DSGraphs and the global DSGraph that contain
// global values.
void CSDataRando::findGlobalNodes(Module &M) {
  DSGraph *GG = DSA->getGlobalsGraph();
  for (auto i = GG->node_begin(), e = GG->node_end(); i != e; i++) {
    GlobalNodes.insert(&*i);
  }

  for (Function &F : M) {
    if ((!F.isDeclaration()) && DSA->hasDSGraph(F)) {
      DSGraph *G = DSA->getDSGraph(F);
      FuncInfo &FI = FunctionInfo[&F];
      DSGraph::NodeMapTy NodeMap;
      G->computeGToGGMapping(NodeMap);
      for (auto i : NodeMap) {
        GlobalNodes.insert(i.first);
        FI.ToGlobalNodeMap[i.first] = i.second.getNode();
      }
    }
  }
}

//
// Function: FoldNodesInDSGraph()
//
// Description:
//  This function will take the specified DSGraph and fold all DSNodes within
//  it that are marked with the heap flag.
//
static void
FoldNodesInDSGraph (DSGraph & Graph) {
  // Worklist of heap nodes to process
  std::vector<DSNodeHandle> HeapNodes;

  //
  // Go find all of the heap nodes.
  //
  DSGraph::node_iterator i;
  DSGraph::node_iterator e = Graph.node_end();
  for (i = Graph.node_begin(); i != e; ++i) {
    DSNode * Node = i;
    if (Node->isHeapNode())
      HeapNodes.push_back (DSNodeHandle(Node));
  }

  //
  // Fold all of the heap nodes; this makes them type-unknown.
  //
  for (unsigned i = 0; i < HeapNodes.size(); ++i)
    HeapNodes[i].getNode()->foldNodeCompletely();
  return;
}

//
// Function: GetNodesReachableFromGlobals()
//
// Description:
//  This function finds all DSNodes which are reachable from globals.  It finds
//  DSNodes both within the local DSGraph as well as in the Globals graph that
//  are reachable from globals.  It does, however, filter out those DSNodes
//  which are of no interest to automatic pool allocation.
//
// Inputs:
//  G - The DSGraph for which to find DSNodes which are reachable by globals.
//      This DSGraph can either by a DSGraph associated with a function *or*
//      it can be the globals graph itself.
//
// Outputs:
//  NodesFromGlobals - A reference to a container object in which to record
//                     DSNodes reachable from globals.  DSNodes are *added* to
//                     this container; it is not cleared by this function.
//                     DSNodes from both the local and globals graph are added.
void
AllHeapNodesHeuristic::GetNodesReachableFromGlobals (DSGraph* G,
                              DenseSet<const DSNode*> &NodesFromGlobals) {
  //
  // Get the globals graph associated with this DSGraph.  If the globals graph
  // is NULL, then the graph that was passed in *is* the globals graph.
  //
  DSGraph * GlobalsGraph = G->getGlobalsGraph();
  if (!GlobalsGraph)
    GlobalsGraph = G;

  //
  // Find all DSNodes which are reachable in the globals graph.
  //
  for (DSGraph::node_iterator NI = GlobalsGraph->node_begin();
       NI != GlobalsGraph->node_end();
       ++NI) {
    NI->markReachableNodes(NodesFromGlobals);
  }

  //
  // Remove those global nodes which we know will never be pool allocated.
  //
  
  std::vector<const DSNode *> toRemove;
  for (DenseSet<const DSNode*>::iterator I = NodesFromGlobals.begin(),
         E = NodesFromGlobals.end(); I != E; ) {
    DenseSet<const DSNode*>::iterator Last = I; ++I;

    const DSNode *tmp = *Last;
    if (!(tmp->isHeapNode())) 
      toRemove.push_back (tmp);
    // Do not poolallocate nodes that are cast to Int.
    // As we do not track through ints, these could be escaping
    if (tmp->isPtrToIntNode())
      toRemove.push_back(tmp);
  }
 
  //
  // Remove all globally reachable DSNodes which do not require pools.
  //
  for (unsigned index = 0; index < toRemove.size(); ++index) {
    NodesFromGlobals.erase(toRemove[index]);
  }

  //
  // Now the fun part.  Find DSNodes in the local graph that correspond to
  // those nodes reachable in the globals graph.  Add them to the set of
  // reachable nodes, too.
  //
  if (G->getGlobalsGraph()) {
    //
    // Compute a mapping between local DSNodes and DSNodes in the globals
    // graph.
    //
    DSGraph::NodeMapTy NodeMap;
    G->computeGToGGMapping (NodeMap);

    //
    // Scan through all DSNodes in the local graph.  If a local DSNode has a
    // corresponding DSNode in the globals graph that is reachable from a 
    // global, then add the local DSNode to the set of DSNodes reachable from a
    // global.
    //
    // FIXME: A node's existance within the global DSGraph is probably
    //        sufficient evidence that it is reachable from a global.
    //

    DSGraph::node_iterator ni = G->node_begin();
    for (; ni != G->node_end(); ++ni) {
      DSNode * N = ni;
      if (NodesFromGlobals.count (NodeMap[N].getNode()))
        NodesFromGlobals.insert (N);
    }
  }
}

//
// Method: findGlobalPoolNodes()
//
// Description:
//  This method finds DSNodes that are reachable from globals and that need a
//  pool.  The Automatic Pool Allocation transform will use the returned
//  information to build global pools for the DSNodes in question.
//
//  For efficiency, this method also determines which DSNodes should be in the
//  same pool.
//
// Outputs:
//  Nodes - The DSNodes that are both reachable from globals and which should
//          have global pools will be *added* to this container.
//
void
AllNodesHeuristic::findGlobalPoolNodes (DSNodeSet_t & Nodes) {
    // Get the globals graph for the program.
    DSGraph* GG = Graphs->getGlobalsGraph();

    //
    // Get all of the nodes reachable from globals.
    //
    DenseSet<const DSNode*> GlobalNodes;
    GetNodesReachableFromGlobals (GG, GlobalNodes);

    //
    // Create a global pool for each global DSNode.
    //
    for (DenseSet<const DSNode *>::iterator NI = GlobalNodes.begin();
            NI != GlobalNodes.end();
            ++NI) {
        const DSNode * N = *NI;
        PoolMap[N] = OnePool(N);
    }

    //
    // Now find all DSNodes belonging to function-local DSGraphs which are
    // mirrored in the globals graph.  These DSNodes require a global pool, too,
    // but must use the same pool as the one assigned to the corresponding global
    // DSNode.
    //
    for (Module::iterator F = M->begin(); F != M->end(); ++F) {
        //
        // Ignore functions that have no DSGraph.
        //
        if (!(Graphs->hasDSGraph(*F))) continue;

        //
        // Compute a mapping between local DSNodes and DSNodes in the globals
        // graph.
        //
        DSGraph* G = Graphs->getDSGraph(*F);
        DSGraph::NodeMapTy NodeMap;
        G->computeGToGGMapping (NodeMap);

        //
        // Scan through all DSNodes in the local graph.  If a local DSNode has a
        // corresponding DSNode in the globals graph that is reachable from a
        // global, then add the local DSNode to the set of DSNodes reachable from
        // a global.
        //
        DSGraph::node_iterator ni = G->node_begin();
        for (; ni != G->node_end(); ++ni) {
            DSNode * N = ni;
            DSNode * GGN = NodeMap[N].getNode();

            assert (!GGN || GlobalNodes.count (GGN));
            if (GGN && GlobalNodes.count (GGN))
                PoolMap[GGN].NodesInPool.push_back (N);
        }
    }

    //
    // Scan through all the local graphs looking for DSNodes which may be
    // reachable by a global.  These nodes may not end up in the globals graph
    // because of the fact that DSA doesn't actually know what is happening to
    // them.
    //
    // FIXME: I believe this code causes a condition in which a local DSNode is
    //        given a local pool in one function but not in other functions.
    //        Someone needs to investigate whether DSA is being consistent here,
    //        and if not, if that inconsistency is correct.
    //
#if 0
    for (Module::iterator F = M->begin(); F != M->end(); ++F) {
        if (F->isDeclaration()) continue;
        DSGraph* G = Graphs->getDSGraph(*F);
        for (DSGraph::node_iterator I = G->node_begin(), E = G->node_end();
                I != E;
                ++I) {
            DSNode * Node = I;
            if (Node->isExternalNode() || Node->isUnknownNode()) {
                GlobalNodes.insert (Node);
            }
        }
    }
#endif

    //
//.........这里部分代码省略.........

static void printCollection(const Collection &C, llvm::raw_ostream &O,
                            const Module *M, const std::string &Prefix) {
  if (M == 0) {
    O << "Null Module pointer, cannot continue!\n";
    return;
  }

  unsigned TotalNumNodes = 0, TotalCallNodes = 0;
  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
    if (C.hasDSGraph(*I)) {
      DSGraph* Gr = C.getDSGraph((const Function&)*I);
      unsigned NumCalls = Gr->shouldUseAuxCalls() ?
        Gr->getAuxFunctionCalls().size() : Gr->getFunctionCalls().size();
      bool IsDuplicateGraph = false;

      //if no only print options, print everything
      bool doPrint = OnlyPrint.begin() == OnlyPrint.end();
      //otherwise check the name
      if (!doPrint)
        doPrint = OnlyPrint.end() !=
        std::find(OnlyPrint.begin(), OnlyPrint.end(), I->getName().str());

      if (doPrint) {
        const Function *SCCFn = Gr->retnodes_begin()->first;
        if (&*I == SCCFn) {
          Gr->writeGraphToFile(O, Prefix+I->getName().str());
        } else {
          IsDuplicateGraph = true; // Don't double count node/call nodes.
          O << "Didn't write '" << Prefix+I->getName().str()
            << ".dot' - Graph already emitted to '" << Prefix+SCCFn->getName().str()
            << "\n";
        }
      } else {
        const Function *SCCFn = Gr->retnodes_begin()->first;
        if (&*I == SCCFn) {
          //O << "Skipped Writing '" << Prefix+I->getName().str() << ".dot'... ["
          //  << Gr->getGraphSize() << "+" << NumCalls << "]\n";
        } else {
          IsDuplicateGraph = true; // Don't double count node/call nodes.
        }
      }

      if (!IsDuplicateGraph) {
        unsigned GraphSize = Gr->getGraphSize();
        if (MaxGraphSize < GraphSize) MaxGraphSize = GraphSize;

        TotalNumNodes += Gr->getGraphSize();
        TotalCallNodes += NumCalls;
        for (DSGraph::node_iterator NI = Gr->node_begin(), E = Gr->node_end();
             NI != E; ++NI)
          if (NI->isNodeCompletelyFolded())
            ++NumFoldedNodes;
      }
    }

  DSGraph* GG = C.getGlobalsGraph();
  TotalNumNodes  += GG->getGraphSize();
  TotalCallNodes += GG->getFunctionCalls().size();
  GG->writeGraphToFile(O, Prefix + "GlobalsGraph");

  O << "\nGraphs contain [" << TotalNumNodes << "+" << TotalCallNodes
    << "] nodes total\n";
}