private List <IStatement> Schedule(DependencyGraph g, IList <IStatement> stmts, bool createFirstIterPostBlocks)
{
List <IStatement> output = new List <IStatement>();
List <StatementBlock> blocks = new List <StatementBlock>();
List <NodeIndex> currentBlock = null;
DirectedGraphFilter <NodeIndex, EdgeIndex> graph2 = new DirectedGraphFilter <NodeIndex, EdgeIndex>(g.dependencyGraph, edge => !g.isDeleted[edge]);
StrongComponents2 <NodeIndex> scc = new StrongComponents2 <NodeIndex>(graph2.SourcesOf, graph2);
scc.AddNode += delegate(NodeIndex node) { currentBlock.Add(node); };
scc.BeginComponent += delegate() { currentBlock = new List <int>(); };
scc.EndComponent += delegate() {
bool isCyclic = false;
if (currentBlock.Count == 1)
{
NodeIndex node = currentBlock[0];
foreach (NodeIndex source in graph2.SourcesOf(node))
{
if (source == node)
{
isCyclic = true;
break;
}
}
}
else
{
isCyclic = true;
}
if (isCyclic)
{
blocks.Add(new Loop()
{
indices = currentBlock
});
}
else
{
blocks.Add(new StraightLine()
{
indices = currentBlock
});
}
};
scc.SearchFrom(graph2.Nodes);
//scc.SearchFrom(g.outputNodes);
bool check = false;
if (check)
{
// check that there are no edges from a later component to an earlier component
Set <NodeIndex> earlierNodes = new Set <int>();
foreach (StatementBlock block in blocks)
{
earlierNodes.AddRange(block.indices);
foreach (NodeIndex node in block.indices)
{
foreach (NodeIndex source in graph2.SourcesOf(node))
{
if (!earlierNodes.Contains(source))
{
Console.WriteLine(g.NodeToString(node) + Environment.NewLine + " depends on later node " + g.NodeToString(source));
Error("Internal error: Strong components are not ordered properly");
}
}
}
}
}
Set <NodeIndex> nodesToMove = new Set <NodeIndex>();
Dictionary <Loop, IBlockStatement> firstIterPostprocessing = null;
if (createFirstIterPostBlocks)
{
firstIterPostprocessing = GetFirstIterPostprocessing(blocks, graph2, stmts, nodesToMove);
}
IVariableDeclaration iteration = Builder.VarDecl("iteration", typeof(int));
IndexedProperty <NodeIndex, bool> isUniform = graph2.CreateNodeData <bool>(true);
foreach (StatementBlock block in blocks)
{
if (block is Loop)
{
foreach (NodeIndex i in block.indices)
{
isUniform[i] = false;
}
IWhileStatement ws = Builder.WhileStmt(Builder.LiteralExpr(true));
IList <IStatement> whileBody = ws.Body.Statements;
if (ContainsIterationStatement(stmts, block.indices))
{
List <IStatement> nodes = new List <IStatement>();
foreach (NodeIndex i in block.indices)
{
IStatement ist = stmts[i];
if (!context.InputAttributes.Has <IterationStatement>(ist))
{
nodes.Add(ist);
}
}
// build a new dependency graph with the dummy iteration statement removed
DependencyGraph g2 = new DependencyGraph(context, nodes, ignoreMissingNodes: true, ignoreRequirements: true);
List <IStatement> sc3 = Schedule(g2, nodes, false);
if (sc3.Count == 1 && sc3[0] is IWhileStatement)
{
ws = (IWhileStatement)sc3[0];
}
else
{
// The statements in the outer loop are not strongly connected.
// Since we want the next transform to only process strong components,
// we mark the outer while loop as DoNotSchedule, leaving only the
// inner while loops to be scheduled.
// add all statements in sc3 to whileBody, but remove while loops around a single statement.
foreach (IStatement ist in sc3)
{
if (ist is IWhileStatement)
{
IWhileStatement iws2 = (IWhileStatement)ist;
if (iws2.Body.Statements.Count == 1)
{
whileBody.AddRange(iws2.Body.Statements);
continue;
}
}
whileBody.Add(ist);
}
context.OutputAttributes.Set(ws, new DoNotSchedule());
}
}
else // !ContainsIterationStatement
{
foreach (NodeIndex i in block.indices)
{
IStatement st = stmts[i];
whileBody.Add(st);
DependencyInformation di = context.InputAttributes.Get <DependencyInformation>(st);
di.AddClones(clonesOfStatement);
}
RegisterUnchangedStatements(whileBody);
}
Loop loop = (Loop)block;
if (firstIterPostprocessing != null && firstIterPostprocessing.ContainsKey(loop))
{
var thenBlock = firstIterPostprocessing[loop];
var iterIsZero = Builder.BinaryExpr(BinaryOperator.ValueEquality, Builder.VarRefExpr(iteration), Builder.LiteralExpr(0));
var firstIterPostStmt = Builder.CondStmt(iterIsZero, thenBlock);
context.OutputAttributes.Set(firstIterPostStmt, new FirstIterationPostProcessingBlock());
whileBody.Add(firstIterPostStmt);
}
output.Add(ws);
}
else
{
// not cyclic
foreach (NodeIndex i in block.indices)
{
IStatement st = stmts[i];
if (!nodesToMove.Contains(i))
{
output.Add(st);
DependencyInformation di = context.InputAttributes.Get <DependencyInformation>(st);
di.AddClones(clonesOfStatement);
}
isUniform[i] = g.IsUniform(i, source => !isUniform[source]);
if (isUniform[i] != g.isUniform[i])
{
Assert.IsTrue(isUniform[i]);
g.isUniform[i] = isUniform[i];
DependencyInformation di = context.InputAttributes.Get <DependencyInformation>(st);
di.IsUniform = isUniform[i];
}
// mark sources of output statements (for SchedulingTransform)
if (g.outputNodes.Contains(i))
{
foreach (NodeIndex source in graph2.SourcesOf(i))
{
IStatement sourceSt = stmts[source];
if (!context.InputAttributes.Has <OutputSource>(sourceSt))
{
context.OutputAttributes.Set(sourceSt, new OutputSource());
}
}
}
}
}
}
return(output);
}
public void GraphSearchTest()
{
// this is the example graph at http://www.codeproject.com/cs/miscctrl/quickgraph.asp
Graph <BasicNode> g = new Graph <BasicNode>();
BasicNode u = new BasicNode("u");
BasicNode v = new BasicNode("v");
BasicNode w = new BasicNode("w");
BasicNode x = new BasicNode("x");
BasicNode y = new BasicNode("y");
BasicNode z = new BasicNode("z");
g.Nodes.Add(u);
g.Nodes.Add(v);
g.Nodes.Add(w);
g.Nodes.Add(x);
g.Nodes.Add(y);
g.Nodes.Add(z);
g.AddEdge(u, v);
g.AddEdge(u, x);
g.AddEdge(v, y);
g.AddEdge(y, x);
g.AddEdge(x, v);
g.AddEdge(w, u);
g.AddEdge(w, y);
g.AddEdge(w, z);
DepthFirstSearch <BasicNode> dfs = new DepthFirstSearch <BasicNode>(g);
dfs.DiscoverNode += delegate(BasicNode node) { Console.WriteLine("discover " + node); };
dfs.FinishNode += delegate(BasicNode node) { Console.WriteLine("finish " + node); };
dfs.DiscoverEdge += delegate(Edge <BasicNode> edge) { Console.WriteLine("discover " + edge); };
dfs.TreeEdge += delegate(Edge <BasicNode> edge) { Console.WriteLine("tree edge " + edge); };
dfs.FinishTreeEdge += delegate(Edge <BasicNode> edge) { Console.WriteLine("finish tree edge " + edge); };
dfs.CrossEdge += delegate(Edge <BasicNode> edge) { Console.WriteLine("cross edge " + edge); };
dfs.BackEdge += delegate(Edge <BasicNode> edge) { Console.WriteLine("back edge " + edge); };
Console.WriteLine("dfs from u:");
dfs.SearchFrom(u);
Console.WriteLine();
Console.WriteLine("dfs from w:");
dfs.SearchFrom(w);
Console.WriteLine();
dfs.Clear();
Console.WriteLine("cleared dfs from w:");
dfs.SearchFrom(w);
Console.WriteLine();
Console.WriteLine("bfs:");
BreadthFirstSearch <BasicNode> bfs = new BreadthFirstSearch <BasicNode>(g);
IndexedProperty <BasicNode, double> distance = g.CreateNodeData <double>(Double.PositiveInfinity);
bfs.DiscoverNode += delegate(BasicNode node) { Console.WriteLine("discover " + node); };
bfs.FinishNode += delegate(BasicNode node) { Console.WriteLine("finish " + node); };
bfs.TreeEdge += delegate(Edge <BasicNode> edge)
{
Console.WriteLine("tree edge " + edge);
distance[edge.Target] = distance[edge.Source] + 1;
};
// compute distances from w
distance[w] = 0;
bfs.SearchFrom(w);
Console.WriteLine("distances from w:");
foreach (BasicNode node in g.Nodes)
{
Console.WriteLine("[" + node + "] " + distance[node]);
}
Assert.Equal(2.0, distance[x]);
Console.WriteLine();
Console.WriteLine("distances from w:");
DistanceSearch <BasicNode> dists = new DistanceSearch <BasicNode>(g);
dists.SetDistance += delegate(BasicNode node, int dist) { Console.WriteLine("[" + node + "] " + dist); };
dists.SearchFrom(w);
Console.WriteLine();
BasicNode start = z, end;
(new PseudoPeripheralSearch <BasicNode>(g)).SearchFrom(ref start, out end);
Console.WriteLine("pseudo-peripheral nodes: " + start + "," + end);
StrongComponents <BasicNode> scc = new StrongComponents <BasicNode>(g);
int count = 0;
scc.AddNode += delegate(BasicNode node) { Console.Write(" " + node); };
scc.BeginComponent += delegate()
{
Console.Write("[");
count++;
};
scc.EndComponent += delegate() { Console.Write("]"); };
Console.Write("strong components reachable from w (topological order): ");
scc.SearchFrom(w);
Assert.Equal(4, count);
Console.WriteLine();
count = 0;
StrongComponents2 <BasicNode> scc2 = new StrongComponents2 <BasicNode>(g);
scc2.AddNode += delegate(BasicNode node) { Console.Write(" " + node); };
scc2.BeginComponent += delegate()
{
Console.Write("[");
count++;
};
scc2.EndComponent += delegate() { Console.Write("]"); };
Console.Write("strong components reachable from w (rev topological order): ");
scc2.SearchFrom(w);
Assert.Equal(4, count);
Console.WriteLine();
#if false
Console.WriteLine("CyclicDependencySort:");
List <BasicNode> schedule = CyclicDependencySort <BasicNode> .Schedule(g,
delegate(BasicNode node, ICollection <BasicNode> available) {
if (node == x)
{
return(available.Contains(u));
}
else
{
return(false);
}
},
g.Nodes);
foreach (BasicNode node in schedule)
{
Console.Write(node + " ");
}
Console.WriteLine();
Assert.Equal <int>(6, schedule.Count);
// order should be: w u x v y z (z can be re-ordered)
Assert.Equal <BasicNode>(w, schedule[0]);
Assert.Equal <BasicNode>(u, schedule[1]);
//Assert.Equal<BasicNode>(z,schedule[5]);
#endif
}
