private void enforceSingleEntry() {
Debug.debugMessage(getClass(), "Enforcing single entry in CFG", 3);
ArrayList<Vertex> noPreds = new ArrayList<Vertex>();
for (Vertex v : cfg) {
if (v.numOfPredecessors() == 0) {
Debug.debugMessage(getClass(), v.getVertexID() + " is currently an entry vertex", 4);
noPreds.add(v);
}
}
while (noPreds.size() > 1) {
int newVertexID = cfg.getNextVertexID();
cfg.addBasicBlock(newVertexID);
Debug.debugMessage(getClass(), "Adding basic block " + newVertexID, 4);
for (int i = 1; i <= MainProgramGenerator.Globals.getFanOut(); ++i) {
if (!noPreds.isEmpty()) {
Vertex v = noPreds.remove(noPreds.size() - 1);
Debug.debugMessage(getClass(), "...and connecting it to " + v.getVertexID(), 4);
if (i == 1) {
cfg.addEdge(newVertexID, v.getVertexID(), BranchType.TAKEN);
} else {
cfg.addEdge(newVertexID, v.getVertexID(), BranchType.NOTTAKEN);
}
}
}
noPreds.add(cfg.getVertex(newVertexID));
}
}
private ArrayList<Integer> setLoopEntryExit(int n, int position) {
ArrayList<Integer> result = new ArrayList<Integer>();
int entryID, exitID;
if (n == 1) {
int id = cfg.getNextVertexID();
cfg.addBasicBlock(id);
entryID = id;
exitID = id;
} else if (n < 3) {
addNonBranchComponents(n);
exitID = disconnectedVertices.get(0);
entryID = disconnectedVertices.get(disconnectedVertices.size() - 1);
} else {
addBranchComponents(n);
exitID = disconnectedBranches.get(0);
entryID = disconnectedBranches.get(disconnectedBranches.size() - 1);
}
if (position == 1) {
result.add(exitID);
result.add(entryID);
} else {
result.add(entryID);
result.add(exitID);
}
return result;
}
void buildIndividualLoops(int loops) {
for (int i = 0; i < loops; ++i) {
int headerID = cfg.getNextVertexID();
Debug.debugMessage(getClass(), "Adding basic block " + headerID, 4);
cfg.addBasicBlock(headerID);
verticesInLoopBody.put(headerID, new ArrayList<Integer>());
int tailID = cfg.getNextVertexID();
Debug.debugMessage(getClass(), "Adding basic block " + tailID, 4);
cfg.addBasicBlock(tailID);
verticesInLoopBody.get(headerID).add(tailID);
if (remainingVertices > 1) {
int loopBody = random.nextInt(remainingVertices / 2 + 1) + 1;
remainingVertices -= loopBody;
decideLoopBody(loopBody, headerID);
Debug.debugMessage(
getClass(), "Adding edge " + headerID + "=>" + disconnectedBranches.get(0), 4);
cfg.addEdge(headerID, disconnectedBranches.get(0), BranchType.TAKEN);
Debug.debugMessage(
getClass(),
"Adding edge "
+ disconnectedBranches.get(disconnectedBranches.size() - 1)
+ "=>"
+ tailID,
4);
cfg.addEdge(
disconnectedBranches.get(disconnectedBranches.size() - 1), tailID, BranchType.TAKEN);
} else {
Debug.debugMessage(getClass(), "Adding edge " + headerID + "=>" + tailID, 4);
cfg.addEdge(headerID, tailID, BranchType.TAKEN);
}
Debug.debugMessage(getClass(), "Adding edge " + tailID + "=>" + headerID, 4);
cfg.addEdge(tailID, headerID, BranchType.TAKEN);
disconnectedLoopsArray.add(headerID);
disconnectedLoops.addVertex(headerID);
}
}
private void buildIndividualBlocks(int noOfComponents) {
for (int i = 0; i < noOfComponents; ++i) {
int branchID = cfg.getNextVertexID();
Debug.debugMessage(getClass(), "Adding basic block " + branchID, 4);
cfg.addBasicBlock(branchID);
int ifBranchID = cfg.getNextVertexID();
Debug.debugMessage(getClass(), "Adding basic block " + ifBranchID, 4);
cfg.addBasicBlock(ifBranchID);
int mergeID = cfg.getNextVertexID();
Debug.debugMessage(getClass(), "Adding basic block " + mergeID, 4);
cfg.addBasicBlock(mergeID);
Debug.debugMessage(getClass(), "Adding edge " + branchID + "=>" + ifBranchID, 4);
cfg.addEdge(branchID, ifBranchID, BranchType.TAKEN);
Debug.debugMessage(getClass(), "Adding edge " + ifBranchID + "=>" + mergeID, 4);
cfg.addEdge(ifBranchID, mergeID, BranchType.TAKEN);
Debug.debugMessage(getClass(), "Adding edge " + branchID + "=>" + mergeID, 4);
cfg.addEdge(branchID, mergeID, BranchType.TAKEN);
disconnectedBranches.add(branchID);
disconnectedBranches.add(mergeID);
}
}
private void addNonBranchComponents(int n) {
disconnectedVertices = new ArrayList<Integer>();
for (int i = 0; i < n; ++i) {
int vertexID = cfg.getNextVertexID();
Debug.debugMessage(getClass(), "Adding basic block " + vertexID, 4);
cfg.addBasicBlock(vertexID);
disconnectedVertices.add(vertexID);
}
for (int i = 0; i < disconnectedVertices.size() - 1; ++i) {
Debug.debugMessage(
getClass(),
"Adding edge " + disconnectedVertices.get(i) + "=>" + disconnectedVertices.get(i + 1),
4);
cfg.addEdge(disconnectedVertices.get(i), disconnectedVertices.get(i + 1), BranchType.TAKEN);
}
}
private void checkExits() {
Debug.debugMessage(getClass(), "Enforcing single exit out of CFG", 3);
ArrayList<Vertex> noSuccs = new ArrayList<Vertex>();
for (Vertex v : cfg) {
if (v.numOfSuccessors() == 0) {
Debug.debugMessage(getClass(), v.getVertexID() + " is currently an exit vertex", 4);
noSuccs.add(v);
}
}
if (noSuccs.size() > MainProgramGenerator.Globals.getNumberOfReturns()) {
int newVertexID = cfg.getNextVertexID();
cfg.addBasicBlock(newVertexID);
Debug.debugMessage(getClass(), "Adding basic block " + newVertexID, 4);
while (!noSuccs.isEmpty()) {
Vertex v = noSuccs.remove(noSuccs.size() - 1);
Debug.debugMessage(getClass(), "...and connecting it from " + v.getVertexID(), 4);
cfg.addEdge(v.getVertexID(), newVertexID, BranchType.TAKEN);
}
}
}
