Пример #1
0
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;
}
Пример #2
0
/*!
	\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;
}