void BottomUpLayout::linearizeCfgImpl() {
assert(irManager->getFlowGraph()->isEdgeProfileConsistent());
StlVector<Edge*> sortedEdges(mm);
const Nodes& nodes = irManager->getFlowGraph()->getNodes();
sortedEdges.reserve(nodes.size() * 3);
for (Nodes::const_iterator it = nodes.begin(), end = nodes.end(); it!=end; ++it) {
Node* node = *it;
const Edges& edges = node->getOutEdges();
sortedEdges.insert(sortedEdges.end(), edges.begin(), edges.end());
}
//GCC 3.4 passes NULLs to comparator if usual std::sort is used here..
std::stable_sort(sortedEdges.begin(), sortedEdges.end(), edge_comparator());
for(StlVector<Edge*>::const_iterator it = sortedEdges.begin(), itEnd = sortedEdges.end(); it!=itEnd; it++) {
Edge* edge = *it;
layoutEdge(edge);
}
//create one-block-chains from blocks that was not laid out
//these blocks are dispatch successors or are blocks connected by in/out edges to already laid out chains
for (Nodes::const_iterator it = nodes.begin(), end = nodes.end(); it!=end; ++it) {
Node* node = *it;
if (node->isBlockNode()) {
BasicBlock* block = (BasicBlock*)node;
if (block->getLayoutSucc() == NULL && !lastInChain[block->getDfNum()]) {
firstInChain[block->getDfNum()] = true;
lastInChain[block->getDfNum()] = true;
}
}
}
combineChains();
}
void BottomUpLayout::layoutEdge(Edge *edge) {
Node* tailNode = edge->getSourceNode();
Node* headNode = edge->getTargetNode();
if (!headNode->isBlockNode() || !tailNode->isBlockNode()) {
return;
}
if (headNode == irManager->getFlowGraph()->getEntryNode()) { //prolog node should be first in layout
return;
}
if (tailNode == headNode) {
return; //backedge to self
}
BasicBlock* tailBlock = (BasicBlock*)tailNode;
if (tailBlock->getLayoutSucc()!=NULL) {
return; //tailBlock is layout predecessor for another successor
}
BasicBlock* headBlock = (BasicBlock*)headNode;
if (prevInLayoutBySuccessorId[headBlock->getDfNum()]!=NULL) {
return; // head was already laid out (in other chain)
}
if (lastInChain[tailBlock->getDfNum()] && firstInChain[headBlock->getDfNum()]) {
BasicBlock* tailOfHeadChain = headBlock;
while (tailOfHeadChain->getLayoutSucc()!=NULL) {
tailOfHeadChain = tailOfHeadChain->getLayoutSucc();
}
if (tailOfHeadChain == tailBlock) {
return; // layout must be acyclic
}
}
tailBlock->setLayoutSucc(headBlock);
prevInLayoutBySuccessorId[headBlock->getDfNum()] = tailBlock;
BasicBlock* tailPred = prevInLayoutBySuccessorId[tailBlock->getDfNum()];
if (tailPred) {
assert(lastInChain[tailBlock->getDfNum()]);
lastInChain[tailBlock->getDfNum()] = false;
} else {
firstInChain[tailBlock->getDfNum()] = true;
}// here we have valid first
firstInChain[headBlock->getDfNum()] = false;
BasicBlock* newLast = headBlock;
while (newLast->getLayoutSucc()!=NULL) {
newLast = newLast->getLayoutSucc();
}
lastInChain[newLast->getDfNum()] = true;
}
