Esempio n. 1
0
void BoundFactsCalculator::NaturalDFS(Node::Ptr cur) {
    nodeColor[cur] = 1;
    NodeIterator nbegin, nend;
    cur->outs(nbegin, nend);

    for (; nbegin != nend; ++nbegin)
        if (nodeColor.find(*nbegin) == nodeColor.end())
	    NaturalDFS(*nbegin);

    reverseOrder.push_back(cur);

}
Esempio n. 2
0
void dfs(Node::Ptr source,
         std::map<Node::Ptr, int> &state,
         std::set<Edge::Ptr> &skipEdges) {

    // DFS from the node given by source
    // If we meet a node twice without having to backtrack first,
    // insert that incoming edge into skipEdges.
    //
    // A node n has state[n] > 0 if it is on the path currently
    // being explored.

    EdgeIterator b, e;
    source->outs(b, e);

    vector<Edge::Ptr> edges;
    for ( ; b!=e; ++b) {
        Edge::Ptr edge = *b;
        edges.push_back(edge);
    }
    std::stable_sort(edges.begin(), edges.end(), edgeSort);

    //state[source]++;
    std::map<Node::Ptr, int>::iterator ssit = state.find(source);
    if(ssit == state.end())
        boost::tuples::tie(ssit,boost::tuples::ignore) =
            state.insert(make_pair(source,1));
    else
        (*ssit).second++;

    vector<Edge::Ptr>::iterator eit = edges.begin();
    for ( ; eit != edges.end(); ++eit) {
        Edge::Ptr edge = *eit;
        Node::Ptr cur = edge->target();

        std::map<Node::Ptr, int>::iterator sit = state.find(cur);
        bool done = (sit != state.end());

        if(done && (*sit).second > 0)
            skipEdges.insert(edge);

        if(!done)
            dfs(cur, state, skipEdges);
    }

    //state[source]--;
    (*ssit).second--;
}
Esempio n. 3
0
bool Graph::printDOT(const std::string& fileName) {
	
    FILE *file = fopen(fileName.c_str(), "w");
    if (file == NULL) {
        return false;
    }
    fprintf(file, "digraph G {\n");

    NodeSet visited;
    std::queue<Node::Ptr> worklist;

    NodeIterator entryBegin, entryEnd;
    entryNodes(entryBegin, entryEnd);

     // Initialize visitor worklist
    for (NodeIterator iter = entryBegin; iter != entryEnd; ++iter) {
        worklist.push(*iter);
    }

    // Put the entry nodes on their own (minimum) rank
    fprintf(file, "  { rank = min;");
    for (NodeIterator iter = entryBegin; iter != entryEnd; ++iter) {
      fprintf(file, "\"%p\"; ", (*iter).get());
    }
    fprintf(file, "}\n");

    NodeIterator exitBegin, exitEnd;
    exitNodes(exitBegin, exitEnd);

    // Put the entry nodes on their own (minimum) rank
    fprintf(file, "  { rank = max;");
    for (NodeIterator iter = exitBegin; iter != exitEnd; ++iter) {
      fprintf(file, "\"%p\"; ", (*iter).get());
    }
    fprintf(file, "}\n");
    

    while (!worklist.empty()) {
        Node::Ptr source = worklist.front();

        worklist.pop();

         //fprintf(stderr, "Considering node %s\n", source->format().c_str());

         // We may have already treated this node...
        if (visited.find(source) != visited.end()) {
             //fprintf(stderr, "\t skipping previously visited node\n");
            continue;
        }
         //fprintf(stderr, "\t inserting %s into visited set, %d elements pre-insert\n", source->format().c_str(), visited.size());
        visited.insert(source);

        fprintf(file, "\t%s\n", source->DOTshape().c_str());
        fprintf(file, "\t%s\n", source->DOTrank().c_str());
	fprintf(file, "\t\"%p\" [label=\"%s\"];\n", 
		source.get(), source->DOTname().c_str());

        NodeIterator outBegin, outEnd;
        source->outs(outBegin, outEnd);

        for (; outBegin != outEnd; ++outBegin) {
            Node::Ptr target = *outBegin;
            if (!target->DOTinclude()) continue;
            //fprintf(file, "\t %s -> %s;\n", source->DOTname().c_str(), target->DOTname().c_str());
	    fprintf(file, "\t \"%p\" -> \"%p\";\n", source.get(), target.get());
            if (visited.find(target) == visited.end()) {
                 //fprintf(stderr, "\t\t adding child %s\n", target->format().c_str());
                worklist.push(target);
            }
            else {
                 //fprintf(stderr, "\t\t skipping previously visited child %s\n", 
                 //target->format().c_str());
            }
        }
    }
    fprintf(file, "}\n\n\n");
    fclose(file);

    return true;
}
Esempio n. 4
0
bool BoundFactsCalculator::CalculateBoundedFacts() {
    /* We use a dataflow analysis to calculate the value bound
     * of each register and potentially some memory locations.
     * The key steps of the dataflow analysis are 
     * 1. Determine the analysis order:
     *    First calculate all strongly connected components (SCC)
     *    of the graph. The flow analysis inside a SCC is 
     *    iterative. The flow analysis between several SCCs
     *    is done topologically. 
     * 2. For each node, need to calculate the meet and 
     *    calculate the transfer function.
     * 1. The meet should be simply an intersection of all the bounded facts 
     * along all paths. 
     * 2. To calculate the transfer function, we first get the symbolic expression
     * of the instrution for the node. Then depending on the instruction operation
     * and the meet result, we know what are still bounded. For example, loading 
     * memory is always unbounded; doing and operation on a register with a constant
     * makes the register bounded. 
     */

    DetermineAnalysisOrder();
    queue<Node::Ptr> workingList;
    unordered_set<Node::Ptr, Node::NodePtrHasher> inQueue;
    unordered_map<Node::Ptr, int, Node::NodePtrHasher> inQueueLimit;

    for (int curOrder = 0; curOrder <= orderStamp; ++curOrder) {
        // We first determine which nodes are
	// in this SCC
        vector<Node::Ptr> curNodes;
	NodeIterator nbegin, nend;
	slice->allNodes(nbegin, nend);
	for (; nbegin != nend; ++nbegin) {
	    if (analysisOrder[*nbegin] == curOrder) {
	        curNodes.push_back(*nbegin);
		workingList.push(*nbegin);
		inQueue.insert(*nbegin);
	    }
	}

	if (!HasIncomingEdgesFromLowerLevel(curOrder, curNodes)) {
	    // If this SCC is an entry SCC,
	    // we choose a node inside the SCC
	    // and let it be top.
	    // This should only contain the virtual entry node
	    parsing_printf("This SCC does not incoming edges from outside\n");
	    boundFactsIn[curNodes[0]] = new BoundFact();
	    boundFactsOut[curNodes[0]] = new BoundFact();
	}
	parsing_printf("Starting analysis inside SCC %d\n", curOrder);
	// We now start iterative analysis inside the SCC
	while (!workingList.empty()) {
	    // We get the current node
	    Node::Ptr curNode = workingList.front();
	    workingList.pop();
	    inQueue.erase(curNode);

	    SliceNode::Ptr node = boost::static_pointer_cast<SliceNode>(curNode);
	    ++inQueueLimit[curNode];
	    if (inQueueLimit[curNode] > IN_QUEUE_LIMIT) continue;

	    BoundFact* oldFactIn = GetBoundFactIn(curNode);
	    parsing_printf("Calculate Meet for %lx", node->addr());
	    if (node->assign()) {
	        parsing_printf(", insn: %s\n", node->assign()->insn()->format().c_str());
	    }
	    else {
	        if (node->block() == NULL)
		    parsing_printf(", the VirtualExit node\n");
		else
		    parsing_printf(", the VirtualEntry node\n");

	    }
	    parsing_printf("\tOld fact for %lx:\n", node->addr());
	    if (oldFactIn == NULL) parsing_printf("\t\t do not exist\n"); else oldFactIn->Print();

	    // We find all predecessors of the current node
	    // and calculates the union of the analysis results
	    // from the predecessors
	    BoundFact* newFactIn = Meet(curNode);
	    parsing_printf("\tNew fact at %lx\n", node->addr());
	    if (newFactIn != NULL) newFactIn->Print(); else parsing_printf("\t\tNot calculated\n");

	    // If the current node has not been calcualted yet,
	    // or the new meet results are different from the
	    // old ones, we keep the new results
	    if (newFactIn != NULL && (oldFactIn == NULL || *oldFactIn != *newFactIn)) {
	        parsing_printf("\tFacts change!\n");
		if (oldFactIn != NULL) delete oldFactIn;
		boundFactsIn[curNode] = newFactIn;
		BoundFact* newFactOut = new BoundFact(*newFactIn);

		// The current node has a transfer function
		// that changes the analysis results
		CalcTransferFunction(curNode, newFactOut);

		if (boundFactsOut.find(curNode) != boundFactsOut.end() && boundFactsOut[curNode] != NULL)
		    delete boundFactsOut[curNode];
		boundFactsOut[curNode] = newFactOut;
		curNode->outs(nbegin, nend);
	        for (; nbegin != nend; ++nbegin)
		    // We only add node inside current SCC into the working list
		    if (inQueue.find(*nbegin) == inQueue.end() && analysisOrder[*nbegin] == curOrder) {
		        workingList.push(*nbegin);
			inQueue.insert(*nbegin);
		    }
	    } else {
	        if (newFactIn != NULL) delete newFactIn;
		parsing_printf("\tFacts do not change!\n");
	    }

        }
    }

    return true;
}