private void addLoops() {
int loops = MainProgramGenerator.Globals.getNumberOfLoops();
int vertices = MainProgramGenerator.Globals.getNumberOfVerticesInCFG();
if (vertices == 1) {
cfg.addBasicBlock(vertices);
} else {
if (loops == 0) {
addNoLoops(vertices);
} else {
int entryID, exitID, endOfExitStructure = 0;
remainingVertices = vertices - 2 * loops;
if (remainingVertices == 2) {
entryID = setLoopEntryExit(1, 0).get(0);
exitID = setLoopEntryExit(1, 1).get(0);
remainingVertices = 0;
} else {
int loopEntry = random.nextInt(remainingVertices / 2) + 1;
remainingVertices -= loopEntry;
entryID = setLoopEntryExit(loopEntry, 0).get(0);
int loopExit = random.nextInt(remainingVertices / 2) + 1;
remainingVertices -= loopExit;
ArrayList<Integer> exit = setLoopEntryExit(loopExit, 1);
exitID = exit.get(0);
endOfExitStructure = exit.get(1);
}
buildIndividualLoops(loops);
initLevelMap();
setLoopTree(loops);
connectLoops();
if (remainingVertices > 0) {
int newExitID = setLoopEntryExit(remainingVertices, 1).get(0);
remainingVertices = 0;
Debug.debugMessage(getClass(), "Adding edge " + endOfExitStructure + "=>" + newExitID, 4);
cfg.addEdge(endOfExitStructure, newExitID, BranchType.TAKEN);
}
Debug.debugMessage(
getClass(), "Adding entry edge " + entryID + "=>" + disconnectedLoopsArray.get(0), 4);
cfg.addEdge(entryID, disconnectedLoopsArray.get(0), BranchType.TAKEN);
Debug.debugMessage(
getClass(), "Adding exit edge " + disconnectedLoopsArray.get(0) + "=>" + exitID, 4);
cfg.addEdge(disconnectedLoopsArray.get(0), exitID, BranchType.TAKEN);
}
}
}
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 void setLoopTree(int loops) {
int loopDepth = MainProgramGenerator.Globals.getLoopNestingDepth();
ArrayList<Integer> loopsArray = new ArrayList<Integer>(disconnectedLoopsArray);
disconnectedLoops.setRootID(loopsArray.remove(0));
levelMap.put(disconnectedLoops.getRootID(), 0);
while (!loopsArray.isEmpty()) {
int loopHeader = loopsArray.remove(loopsArray.size() - 1);
ArrayList<Integer> candidateHeaders = new ArrayList<Integer>();
for (Integer key : levelMap.keySet()) {
int level = levelMap.get(key);
if (level != -1 && level <= loopDepth) {
candidateHeaders.add(key);
}
}
int predecessors = random.nextInt(candidateHeaders.size()) + 1;
for (int i = 1; i <= predecessors; ++i) {
int predecessorIndex = random.nextInt(candidateHeaders.size());
int predecessorID = candidateHeaders.remove(predecessorIndex);
disconnectedLoops.addEdge(predecessorID, loopHeader);
if (levelMap.get(predecessorID) > levelMap.get(loopHeader)) {
levelMap.put(loopHeader, levelMap.get(predecessorID) + 1);
}
}
}
disconnectedLoops.setHeight();
}
private void addSelfLoops() {
int counter = MainProgramGenerator.Globals.getNumberOfSelfLoops();
while (counter > 0) {
int vertexID;
do {
vertexID = random.nextInt(cfg.numOfVertices() + 1);
} while (vertexID == cfg.getEntryID());
Debug.debugMessage(getClass(), "Adding self-loop " + vertexID + " => " + vertexID, 4);
cfg.addEdge(vertexID, vertexID, BranchType.TAKEN);
counter--;
}
}
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);
}
}
}
