ControlFlowGraph::BlockPointerVector
ControlFlowGraph::reverse_topological_sequence() {
typedef std::set<iterator, BlockSetCompare> BlockSet;
typedef std::queue<iterator> Queue;
report("Creating reverse topological order traversal");
BlockSet visited;
BlockPointerVector sequence;
Queue queue;
queue.push(get_exit_block());
while (sequence.size() != size()) {
if(queue.empty()) {
for (pointer_iterator block = sequence.begin();
block != sequence.end(); ++block) {
for (pointer_iterator pred = (*block)->predecessors.begin();
pred != (*block)->predecessors.end(); ++pred) {
if (visited.count(*pred) == 0) {
queue.push(*pred);
break;
}
}
if(!queue.empty()) {
break;
}
}
if(queue.empty()) break; // The remaining blocks are unreachable
}
iterator current = queue.front();
queue.pop();
if(!visited.insert(current).second) continue;
sequence.push_back(current);
report(" Adding block " << current->label());
for (pointer_iterator block = current->predecessors.begin();
block != current->predecessors.end(); ++block) {
bool noDependencies = true;
for (pointer_iterator successor = (*block)->successors.begin();
successor != (*block)->successors.end(); ++successor) {
if (visited.count(*successor) == 0) {
noDependencies = false;
break;
}
}
if(noDependencies) {
queue.push(*block);
}
}
}
return sequence;
}
/*!
\brief performs a topological sort to maximize reconvergence opportunities and ensure forward progress
*/
ir::ControlFlowGraph::BlockPointerVector ir::HammockGraph::topological_sequence() {
typedef ir::ControlFlowGraph::BlockPointerVector BlockPointerVector;
std::set< int > scheduled;
BlockPointerVector sequence;
schedule_hammock(sequence, scheduled, domTree.blocksToIndex[ domTree.blocks[0] ],
domTree.blocksToIndex[ pdomTree.blocks[0] ]);
// tests:
// are all blocks scheduled exactly once?
// is the entry node the first block?
// are hammocks scheduled correctly?
report("schedule:");
for (BlockPointerVector::iterator bb_it = sequence.begin(); bb_it != sequence.end(); ++bb_it) {
report(" " << (*bb_it)->label);
}
return sequence;
}
