private static ISet <CFGEdge> IdentifyBackEdges(ControlFlowGraph cfg)
{
var back_edges = new HashSet <CFGEdge>();
foreach (var node in cfg.Nodes)
{
foreach (var succ in node.Successors)
{
if (node.Dominators.Contains(succ))
{
var edge = new CFGEdge(node, succ);
back_edges.Add(edge);
}
}
}
return(back_edges);
}
private static CFGLoop IdentifyLoop(CFGEdge back_edge)
{
var loop = new CFGLoop(back_edge.Target);
var nodes = new Stack <CFGNode>();
nodes.Push(back_edge.Source);
do
{
var node = nodes.Pop();
var new_node = loop.Body.Add(node);
if (new_node)
{
foreach (var pred in node.Predecessors)
{
nodes.Push(pred);
}
}
}while (nodes.Count > 0);
return(loop);
}