llvm-6502/lib/Transforms/Instrumentation/ProfilePaths/Graph.cpp
Chris Lattner fd1717d03b * Changes to compile successfully with GCC 3.0
* Eliminated memory leak in processGraph
* Pass vectors by const reference to moveDummyCode instead of by copy


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1808 91177308-0d34-0410-b5e6-96231b3b80d8
2002-02-26 19:40:28 +00:00

433 lines
12 KiB
C++

//===--Graph.cpp--- implements Graph class ---------------- ------*- C++ -*--=//
//
// This implements Graph for helping in trace generation
// This graph gets used by "ProfilePaths" class
//
//===----------------------------------------------------------------------===//
#include "Graph.h"
#include "llvm/BasicBlock.h"
#include <algorithm>
#include <iostream>
using std::list;
using std::set;
using std::map;
using std::vector;
using std::cerr;
static const graphListElement *findNodeInList(const Graph::nodeList &NL,
Node *N) {
for(Graph::nodeList::const_iterator NI = NL.begin(), NE=NL.end(); NI != NE;
++NI)
if (*NI->element== *N)
return &*NI;
return 0;
}
static graphListElement *findNodeInList(Graph::nodeList &NL, Node *N) {
for(Graph::nodeList::iterator NI = NL.begin(), NE=NL.end(); NI != NE; ++NI)
if (*NI->element== *N)
return &*NI;
return 0;
}
//graph constructor with root and exit specified
Graph::Graph(std::set<Node*> n, std::set<Edge> e,
Node *rt, Node *lt){
strt=rt;
ext=lt;
for(set<Node* >::iterator x=n.begin(), en=n.end(); x!=en; ++x)
nodes[*x] = list<graphListElement>();
for(set<Edge >::iterator x=e.begin(), en=e.end(); x!=en; ++x){
Edge ee=*x;
int w=ee.getWeight();
nodes[ee.getFirst()].push_front(graphListElement(ee.getSecond(),w));
}
}
//check whether graph has an edge
//having an edge simply means that there is an edge in the graph
//which has same endpoints as the given edge
bool Graph::hasEdge(Edge ed) const{
if(ed.isNull())
return false;
nodeList nli=getNodeList(ed.getFirst());
Node *nd2=ed.getSecond();
return (findNodeInList(nli,nd2)!=NULL);
}
//check whether graph has an edge, with a given wt
//having an edge simply means that there is an edge in the graph
//which has same endpoints as the given edge
//This function checks, moreover, that the wt of edge matches too
bool Graph::hasEdgeAndWt(Edge ed) const{
if(ed.isNull())
return false;
Node *nd2=ed.getSecond();
nodeList nli=getNodeList(ed.getFirst());
for(nodeList::iterator NI=nli.begin(), NE=nli.end(); NI!=NE; ++NI)
if(*NI->element == *nd2 && ed.getWeight()==NI->weight)
return true;
return false;
}
//add a node
void Graph::addNode(Node *nd){
list<Node *> lt=getAllNodes();
for(list<Node *>::iterator LI=lt.begin(), LE=lt.end(); LI!=LE;++LI){
if(**LI==*nd)
return;
}
nodes[nd] = list<graphListElement>();
}
//add an edge
//this adds an edge ONLY when
//the edge to be added doesn not already exist
//we "equate" two edges here only with their
//end points
void Graph::addEdge(Edge ed, int w){
nodeList &ndList = nodes[ed.getFirst()];
Node *nd2=ed.getSecond();
if(findNodeInList(nodes[ed.getFirst()], nd2))
return;
ndList.push_front(graphListElement(nd2,w));
}
//add an edge EVEN IF such an edge already exists
//this may make a multi-graph
//which does happen when we add dummy edges
//to the graph, for compensating for back-edges
void Graph::addEdgeForce(Edge ed){
nodes[ed.getFirst()].push_front(graphListElement(ed.getSecond(),
ed.getWeight()));
}
//remove an edge
//Note that it removes just one edge,
//the first edge that is encountered
void Graph::removeEdge(Edge ed){
nodeList &ndList = nodes[ed.getFirst()];
Node &nd2 = *ed.getSecond();
for(nodeList::iterator NI=ndList.begin(), NE=ndList.end(); NI!=NE ;++NI) {
if(*NI->element == nd2) {
ndList.erase(NI);
break;
}
}
}
//set the weight of an edge
void Graph::setWeight(Edge ed){
graphListElement *El = findNodeInList(nodes[ed.getFirst()], ed.getSecond());
if (El)
El->weight=ed.getWeight();
}
//get the list of successor nodes
list<Node *> Graph::getSuccNodes(Node *nd) const {
nodeMapTy::const_iterator nli = nodes.find(nd);
assert(nli != nodes.end() && "Node must be in nodes map");
const nodeList &nl = nli->second;
list<Node *> lt;
for(nodeList::const_iterator NI=nl.begin(), NE=nl.end(); NI!=NE; ++NI)
lt.push_back(NI->element);
return lt;
}
//get the list of predecessor nodes
list<Node *> Graph::getPredNodes(Node *nd) const{
list<Node *> lt;
for(nodeMapTy::const_iterator EI=nodes.begin(), EE=nodes.end(); EI!=EE ;++EI){
Node *lnode=EI->first;
const nodeList &nl = getNodeList(lnode);
const graphListElement *N = findNodeInList(nl, nd);
if (N) lt.push_back(lnode);
}
return lt;
}
//get the list of all the vertices in graph
list<Node *> Graph::getAllNodes() const{
list<Node *> lt;
for(nodeMapTy::const_iterator x=nodes.begin(), en=nodes.end(); x != en; ++x)
lt.push_back(x->first);
return lt;
}
//class to compare two nodes in graph
//based on their wt: this is used in
//finding the maximal spanning tree
struct compare_nodes {
bool operator()(Node *n1, Node *n2){
return n1->getWeight() < n2->getWeight();
}
};
static void printNode(Node *nd){
cerr<<"Node:"<<nd->getElement()->getName()<<"\n";
}
//Get the Maximal spanning tree (also a graph)
//of the graph
Graph* Graph::getMaxSpanningTree(){
//assume connected graph
Graph *st=new Graph();//max spanning tree, undirected edges
int inf=9999999;//largest key
list<Node *> lt = getAllNodes();
//initially put all vertices in vector vt
//assign wt(root)=0
//wt(others)=infinity
//
//now:
//pull out u: a vertex frm vt of min wt
//for all vertices w in vt,
//if wt(w) greater than
//the wt(u->w), then assign
//wt(w) to be wt(u->w).
//
//make parent(u)=w in the spanning tree
//keep pulling out vertices from vt till it is empty
vector<Node *> vt;
map<Node*, Node* > parent;
map<Node*, int > ed_weight;
//initialize: wt(root)=0, wt(others)=infinity
//parent(root)=NULL, parent(others) not defined (but not null)
for(list<Node *>::iterator LI=lt.begin(), LE=lt.end(); LI!=LE; ++LI){
Node *thisNode=*LI;
if(*thisNode == *getRoot()){
thisNode->setWeight(0);
parent[thisNode]=NULL;
ed_weight[thisNode]=0;
}
else{
thisNode->setWeight(inf);
}
st->addNode(thisNode);//add all nodes to spanning tree
//we later need to assign edges in the tree
vt.push_back(thisNode); //pushed all nodes in vt
}
//keep pulling out vertex of min wt from vt
while(!vt.empty()){
Node *u=*(min_element(vt.begin(), vt.end(), compare_nodes()));
#ifdef DEBUG_PATH_PROFILES
cerr<<"popped wt"<<(u)->getWeight()<<"\n";
printNode(u);
#endif
if(parent[u]!=NULL){ //so not root
Edge edge(parent[u],u, ed_weight[u]); //assign edge in spanning tree
st->addEdge(edge,ed_weight[u]);
#ifdef DEBUG_PATH_PROFILES
cerr<<"added:\n";
printEdge(edge);
#endif
}
//vt.erase(u);
//remove u frm vt
for(vector<Node *>::iterator VI=vt.begin(), VE=vt.end(); VI!=VE; ++VI){
if(**VI==*u){
vt.erase(VI);
break;
}
}
//assign wt(v) to all adjacent vertices v of u
//only if v is in vt
Graph::nodeList nl=getNodeList(u);
for(nodeList::iterator NI=nl.begin(), NE=nl.end(); NI!=NE; ++NI){
Node *v=NI->element;
int weight=-NI->weight;
//check if v is in vt
bool contains=false;
for(vector<Node *>::iterator VI=vt.begin(), VE=vt.end(); VI!=VE; ++VI){
if(**VI==*v){
contains=true;
break;
}
}
#ifdef DEBUG_PATH_PROFILES
cerr<<"wt:v->wt"<<weight<<":"<<v->getWeight()<<"\n";
printNode(v);cerr<<"node wt:"<<(*v).weight<<"\n";
#endif
//so if v in in vt, change wt(v) to wt(u->v)
//only if wt(u->v)<wt(v)
if(contains && weight<v->getWeight()){
parent[v]=u;
ed_weight[v]=weight;
v->setWeight(weight);
#ifdef DEBUG_PATH_PROFILES
cerr<<v->getWeight()<<":Set weight------\n";
printGraph();
printEdge(Edge(u,v,weight));
#endif
}
}
}
return st;
}
//print the graph (for debugging)
void Graph::printGraph(){
list<Node *> lt=getAllNodes();
cerr<<"Graph---------------------\n";
for(list<Node *>::iterator LI=lt.begin(), LE=lt.end(); LI!=LE; ++LI){
cerr<<((*LI)->getElement())->getName()<<"->";
Graph::nodeList nl=getNodeList(*LI);
for(Graph::nodeList::iterator NI=nl.begin(), NE=nl.end(); NI!=NE; ++NI){
cerr<<":"<<"("<<(NI->element->getElement())
->getName()<<":"<<NI->element->getWeight()<<","<<NI->weight<<")";
}
cerr<<"--------\n";
}
}
//get a list of nodes in the graph
//in r-topological sorted order
//note that we assumed graph to be connected
list<Node *> Graph::reverseTopologicalSort() const{
list <Node *> toReturn;
list<Node *> lt=getAllNodes();
for(list<Node *>::iterator LI=lt.begin(), LE=lt.end(); LI!=LE; ++LI){
if((*LI)->getWeight()!=GREY && (*LI)->getWeight()!=BLACK)
DFS_Visit(*LI, toReturn);
}
return toReturn;
}
//a private method for doing DFS traversal of graph
//this is used in determining the reverse topological sort
//of the graph
void Graph::DFS_Visit(Node *nd, list<Node *> &toReturn) const {
nd->setWeight(GREY);
list<Node *> lt=getSuccNodes(nd);
for(list<Node *>::iterator LI=lt.begin(), LE=lt.end(); LI!=LE; ++LI){
if((*LI)->getWeight()!=GREY && (*LI)->getWeight()!=BLACK)
DFS_Visit(*LI, toReturn);
}
toReturn.push_back(nd);
}
//Ordinarily, the graph is directional
//this converts the graph into an
//undirectional graph
//This is done by adding an edge
//v->u for all existing edges u->v
void Graph::makeUnDirectional(){
list<Node* > allNodes=getAllNodes();
for(list<Node *>::iterator NI=allNodes.begin(), NE=allNodes.end(); NI!=NE;
++NI) {
nodeList nl=getNodeList(*NI);
for(nodeList::iterator NLI=nl.begin(), NLE=nl.end(); NLI!=NLE; ++NLI){
Edge ed(NLI->element, *NI, NLI->weight);
if(!hasEdgeAndWt(ed)){
#ifdef DEBUG_PATH_PROFILES
cerr<<"######doesn't hv\n";
printEdge(ed);
#endif
addEdgeForce(ed);
}
}
}
}
//reverse the sign of weights on edges
//this way, max-spanning tree could be obtained
//usin min-spanning tree, and vice versa
void Graph::reverseWts(){
list<Node *> allNodes=getAllNodes();
for(list<Node *>::iterator NI=allNodes.begin(), NE=allNodes.end(); NI!=NE;
++NI) {
nodeList node_list=getNodeList(*NI);
for(nodeList::iterator NLI=nodes[*NI].begin(), NLE=nodes[*NI].end();
NLI!=NLE; ++NLI)
NLI->weight=-NLI->weight;
}
}
//getting the backedges in a graph
//Its a variation of DFS to get the backedges in the graph
//We get back edges by associating a time
//and a color with each vertex.
//The time of a vertex is the time when it was first visited
//The color of a vertex is initially WHITE,
//Changes to GREY when it is first visited,
//and changes to BLACK when ALL its neighbors
//have been visited
//So we have a back edge when we meet a successor of
//a node with smaller time, and GREY color
void Graph::getBackEdges(vector<Edge > &be) const{
map<Node *, Color > color;
map<Node *, int > d;
list<Node *> allNodes=getAllNodes();
int time=0;
for(list<Node *>::const_iterator NI=allNodes.begin(), NE=allNodes.end();
NI!=NE; ++NI){
if(color[*NI]!=GREY && color[*NI]!=BLACK)
getBackEdgesVisit(*NI, be, color, d, time);
}
}
//helper function to get back edges: it is called by
//the "getBackEdges" function above
void Graph::getBackEdgesVisit(Node *u, vector<Edge > &be,
map<Node *, Color > &color,
map<Node *, int > &d, int &time) const{
color[u]=GREY;
time++;
d[u]=time;
list<Node *> succ_list=getSuccNodes(u);
for(list<Node *>::const_iterator v=succ_list.begin(), ve=succ_list.end();
v!=ve; ++v){
if(color[*v]!=GREY && color[*v]!=BLACK){
getBackEdgesVisit(*v, be, color, d, time);
}
//now checking for d and f vals
if(color[*v]==GREY){
//so v is ancestor of u if time of u > time of v
if(d[u] >= d[*v]){
Edge *ed=new Edge(u, *v);
if (!(*u == *getExit() && **v == *getRoot()))
be.push_back(*ed); // choose the forward edges
}
}
}
color[u]=BLACK;//done with visiting the node and its neighbors
}