/// <summary>
/// Returns all nodes in the schedule whose target appears prior to the node.
/// </summary>
/// <param name="g"></param>
/// <param name="schedule"></param>
/// <returns></returns>
internal static Set <NodeIndex> CollectUses(IndexedGraph g, IEnumerable <NodeIndex> schedule)
{
Set <NodeIndex> uses = new Set <NodeIndex>();
Set <NodeIndex> available = new Set <NodeIndex>();
foreach (NodeIndex node in schedule)
{
foreach (NodeIndex source in g.SourcesOf(node))
{
if (!available.Contains(source))
{
uses.Add(source);
}
}
available.Add(node);
}
return(uses);
}
/// <summary>
/// Returns all nodes in the schedule whose target appears prior to the node.
/// </summary>
/// <param name="g"></param>
/// <param name="schedule"></param>
/// <param name="isDeleted"></param>
/// <returns></returns>
internal static Set <NodeIndex> CollectUses(IndexedGraph g, IEnumerable <NodeIndex> schedule, Func <EdgeIndex, bool> isDeleted = null)
{
Set <NodeIndex> uses = new Set <NodeIndex>();
Set <NodeIndex> available = new Set <NodeIndex>();
foreach (NodeIndex node in schedule)
{
foreach (EdgeIndex edge in g.EdgesInto(node).Where(e => isDeleted == null || !isDeleted(e)))
{
NodeIndex source = g.SourceOf(edge);
if (!available.Contains(source))
{
uses.Add(source);
}
}
available.Add(node);
}
return(uses);
}
int CalculateNodeDepth(IndexedGraph <string, Orbit> orbits)
{
foreach (var orbit in orbits.DepthFirstWalk())
{
if (orbit.Name != "COM")
{
orbit.Depth = orbits.GetParent(orbit).Depth + 1;
}
}
var total = 0;
foreach (var orbit in orbits.DepthFirstWalk())
{
total += orbit.Depth;
}
return(total);
}
IndexedGraph <string, Orbit> BuildOrbits(Dictionary <string, string> orbitsDef)
{
var orbits = new IndexedGraph <string, Orbit>();
orbits["COM"] = new Orbit("COM");
foreach (var orbit in orbitsDef.Keys)
{
orbits[orbit] = new Orbit(orbit);
}
foreach (var orbit in orbitsDef)
{
orbits.AddParentChildLink(orbit.Value, orbit.Key);
}
orbits.Root = orbits["COM"];
return(orbits);
}
internal static IEnumerable <NodeIndex> GetOverwrites(BasicTransformContext context, IndexedGraph dependencyGraph, NodeIndex writer,
List <IStatement> nodes, Dictionary <IStatement, int> indexOfNode)
{
IStatement ist = nodes[writer];
DependencyInformation di = context.InputAttributes.Get <DependencyInformation>(ist);
if (di == null)
{
context.Error("Dependency information not found for statement: " + ist);
di = new DependencyInformation();
}
foreach (IStatement previousWriteStmt in di.Overwrites)
{
NodeIndex previousWriter = indexOfNode[previousWriteStmt];
if (previousWriter < writer)
{
yield return(previousWriter);
}
}
}
public void VisualizeDependencyGraph(IndexedGraph dg, IEnumerable <EdgeStylePredicate> edgeStyles = null, Func <int, string> nodeName = null, Func <int, string> edgeName = null, string visualizationTitle = "Dependency_Graph")
{
DependencyGraphView view = new DependencyGraphView(dg, edgeStyles, nodeName, edgeName);
view.Show(visualizationTitle);
}
protected override void DoConvertMethodBody(IList <IStatement> outputs, IList <IStatement> inputs)
{
List <int> whileNumberOfNode = new List <int>();
List <int> fusedCountOfNode = new List <int>();
List <List <IStatement> > containersOfNode = new List <List <IStatement> >();
// the code may have multiple while(true) loops, however these must be disjoint.
// therefore we treat 'while' as one container, but give each loop a different 'while number'.
int outerWhileCount = 0;
int currentOuterWhileNumber = 0;
int currentFusedCount = 0;
List <Set <IVariableDeclaration> > loopVarsOfWhileNumber = new List <Set <IVariableDeclaration> >();
// build the dependency graph
var g = new DependencyGraph2(context, inputs, DependencyGraph2.BackEdgeHandling.Ignore,
delegate(IWhileStatement iws)
{
if (iws is IFusedBlockStatement)
{
if (iws.Condition is IVariableReferenceExpression)
{
currentFusedCount++;
}
}
else
{
outerWhileCount++;
currentOuterWhileNumber = outerWhileCount;
}
},
delegate(IWhileStatement iws)
{
if (iws is IFusedBlockStatement)
{
if (iws.Condition is IVariableReferenceExpression)
{
currentFusedCount--;
}
}
else
{
currentOuterWhileNumber = 0;
}
},
delegate(IConditionStatement ics)
{
},
delegate(IConditionStatement ics)
{
},
delegate(IStatement ist, int targetIndex)
{
int whileNumber = currentOuterWhileNumber;
whileNumberOfNode.Add(whileNumber);
fusedCountOfNode.Add(currentFusedCount);
List <IStatement> containers = new List <IStatement>();
LoopMergingTransform.UnwrapStatement(ist, containers);
containersOfNode.Add(containers);
for (int i = 0; i < currentFusedCount; i++)
{
if (containers[i] is IForStatement ifs)
{
var loopVar = Recognizer.LoopVariable(ifs);
if (loopVarsOfWhileNumber.Count <= whileNumber)
{
while (loopVarsOfWhileNumber.Count <= whileNumber)
{
loopVarsOfWhileNumber.Add(new Set <IVariableDeclaration>());
}
}
Set <IVariableDeclaration> loopVars = loopVarsOfWhileNumber[whileNumber];
loopVars.Add(loopVar);
}
}
});
var nodes = g.nodes;
var dependencyGraph = g.dependencyGraph;
for (int whileNumber = 1; whileNumber < loopVarsOfWhileNumber.Count; whileNumber++)
{
foreach (var loopVar in loopVarsOfWhileNumber[whileNumber])
{
// Any statement (in the while loop) that has a forward descendant and a backward descendant will be cloned, so we want to minimize the number of such nodes.
// The free variables in this problem are the loop directions at the leaf statements, since all other loop directions are forced by these.
// We find the optimal labeling of the free variables by solving a min cut problem on a special network.
// The network is constructed so that the cost of a cut is equal to the number of statements that will be cloned.
// The network has 2 nodes for every statement: an in-node and an out-node.
// For a non-leaf statement, there is a capacity 1 edge from the in-node to out-node. This edge is cut when the statement is cloned.
// For a leaf statement, there is an infinite capacity edge in both directions, or equivalently a single node.
// If statement A depends on statement B, then there is an infinite capacity edge from in-A to in-B, and from out-B to out-A,
// representing the fact that cloning A requires cloning B, but not the reverse.
// If a statement must appear with a forward loop, it is connected to the source.
// If a statement must appear with a backward loop, it is connected to the sink.
// construct a capacitated graph
int inNodeStart = 0;
int outNodeStart = inNodeStart + dependencyGraph.Nodes.Count;
int sourceNode = outNodeStart + dependencyGraph.Nodes.Count;
int sinkNode = sourceNode + 1;
int cutNodeCount = sinkNode + 1;
Func <NodeIndex, int> getInNode = node => node + inNodeStart;
Func <NodeIndex, int> getOutNode = node => node + outNodeStart;
IndexedGraph network = new IndexedGraph(cutNodeCount);
const float infinity = 1000000f;
List <float> capacity = new List <float>();
List <NodeIndex> nodesOfInterest = new List <NodeIndex>();
foreach (var node in dependencyGraph.Nodes)
{
if (whileNumberOfNode[node] != whileNumber)
{
continue;
}
NodeIndex source = node;
List <IStatement> containersOfSource = containersOfNode[source];
bool hasLoopVar = containersOfSource.Any(container => container is IForStatement && Recognizer.LoopVariable((IForStatement)container) == loopVar);
if (!hasLoopVar)
{
continue;
}
nodesOfInterest.Add(node);
IStatement sourceSt = nodes[source];
var readAfterWriteEdges = dependencyGraph.EdgesOutOf(source).Where(edge => !g.isWriteAfterRead[edge]);
bool isLeaf = true;
int inNode = getInNode(node);
int outNode = getOutNode(node);
foreach (var target in readAfterWriteEdges.Select(dependencyGraph.TargetOf))
{
List <IStatement> containersOfTarget = containersOfNode[target];
IStatement targetSt = nodes[target];
ForEachMatchingLoopVariable(containersOfSource, containersOfTarget, (loopVar2, afs, bfs) =>
{
if (loopVar2 == loopVar)
{
int inTarget = getInNode(target);
int outTarget = getOutNode(target);
network.AddEdge(inTarget, inNode);
capacity.Add(infinity);
network.AddEdge(outNode, outTarget);
capacity.Add(infinity);
isLeaf = false;
}
});
}
if (isLeaf)
{
if (debug)
{
log.Add($"loopVar={loopVar.Name} leaf {sourceSt}");
}
network.AddEdge(inNode, outNode);
capacity.Add(infinity);
network.AddEdge(outNode, inNode);
capacity.Add(infinity);
}
else
{
network.AddEdge(inNode, outNode);
capacity.Add(1f);
}
int fusedCount = fusedCountOfNode[node];
Direction desiredDirectionOfSource = GetDesiredDirection(loopVar, containersOfSource, fusedCount);
if (desiredDirectionOfSource == Direction.Forward)
{
if (debug)
{
log.Add($"loopVar={loopVar.Name} forward {sourceSt}");
}
network.AddEdge(sourceNode, inNode);
capacity.Add(infinity);
}
else if (desiredDirectionOfSource == Direction.Backward)
{
if (debug)
{
log.Add($"loopVar={loopVar.Name} backward {sourceSt}");
}
network.AddEdge(outNode, sinkNode);
capacity.Add(infinity);
}
}
network.IsReadOnly = true;
// compute the min cut
MinCut <NodeIndex, EdgeIndex> mc = new MinCut <EdgeIndex, EdgeIndex>(network, e => capacity[e]);
mc.Sources.Add(sourceNode);
mc.Sinks.Add(sinkNode);
Set <NodeIndex> sourceGroup = mc.GetSourceGroup();
foreach (NodeIndex node in nodesOfInterest)
{
IStatement sourceSt = nodes[node];
bool forwardIn = sourceGroup.Contains(getInNode(node));
bool forwardOut = sourceGroup.Contains(getOutNode(node));
if (forwardIn != forwardOut)
{
if (debug)
{
log.Add($"loopVar={loopVar.Name} will clone {sourceSt}");
}
}
else if (forwardIn)
{
if (debug)
{
log.Add($"loopVar={loopVar.Name} wants forward {sourceSt}");
}
}
else
{
if (debug)
{
log.Add($"loopVar={loopVar.Name} wants backward {sourceSt}");
}
var containers = containersOfNode[node];
bool isForwardLoop = true;
foreach (var container in containers)
{
if (container is IForStatement)
{
IForStatement ifs = (IForStatement)container;
if (Recognizer.LoopVariable(ifs) == loopVar)
{
isForwardLoop = Recognizer.IsForwardLoop(ifs);
}
}
}
if (isForwardLoop)
{
Set <IVariableDeclaration> loopVarsToReverse;
if (!loopVarsToReverseInStatement.TryGetValue(sourceSt, out loopVarsToReverse))
{
// TODO: re-use equivalent sets
loopVarsToReverse = new Set <IVariableDeclaration>();
loopVarsToReverseInStatement.Add(sourceSt, loopVarsToReverse);
}
loopVarsToReverse.Add(loopVar);
}
}
}
}
}
base.DoConvertMethodBody(outputs, inputs);
}
public IndexedAStarPathFinder(IndexedGraph <N> graph) : this(graph, false)
{
}
public void VisualizeDependencyGraph(IndexedGraph dg, IEnumerable <EdgeStylePredicate> edgeStyles = null, Func <int, string> nodeName = null, Func <int, string> edgeName = null, string visualizationTitle = "Infer.NET Dependency Graph Viewer")
{
var view = new DependencyGraphView(dg, edgeStyles, nodeName, edgeName);
view.RunInForm(visualizationTitle);
}
internal DependencyGraphView(IndexedGraph dg, IEnumerable <EdgeStylePredicate> edgeStyles = null,
Func <NodeIndex, string> nodeName = null,
Func <EdgeIndex, string> edgeName = null)
{
this.dg = dg;
this.edgeStyles = edgeStyles;
this.nodeName = nodeName;
this.edgeName = edgeName;
nodeOf = dg.CreateNodeData <Node>(null);
OnGraphChanged();
panel.Dock = DockStyle.Fill;
gviewer.Dock = DockStyle.Fill;
panel.Controls.Add(gviewer);
if (edgeStyles != null)
{
// draw the legend
TableLayoutPanel legend = new TableLayoutPanel();
legend.AutoSize = true;
legend.ColumnCount = 2 * edgeStyles.Count();
foreach (EdgeStylePredicate esp in edgeStyles)
{
PictureBox pic = new PictureBox();
pic.SizeMode = PictureBoxSizeMode.AutoSize;
legend.Controls.Add(pic);
int size = 8;
var bitmap = new System.Drawing.Bitmap(size, size);
var graphics = System.Drawing.Graphics.FromImage(bitmap);
var color = System.Drawing.Color.Black;
if ((esp.Style & EdgeStyle.Dimmed) > 0)
{
color = System.Drawing.Color.LightGray;
}
else if ((esp.Style & EdgeStyle.Back) > 0)
{
color = System.Drawing.Color.Red;
}
else if ((esp.Style & EdgeStyle.Blue) > 0)
{
color = System.Drawing.Color.Blue;
}
int width = 1;
if ((esp.Style & EdgeStyle.Bold) > 0)
{
width = 2;
}
var pen = new System.Drawing.Pen(color, width);
if ((esp.Style & EdgeStyle.Dashed) > 0)
{
pen.DashStyle = System.Drawing.Drawing2D.DashStyle.Dash;
}
int y = bitmap.Height / 2;
graphics.DrawLine(pen, 0, y, bitmap.Width - 1, y);
pic.Image = bitmap;
ToolLabel label = new ToolLabel();
label.Text = esp.Name;
label.AutoSize = true;
legend.Controls.Add(label);
}
legend.Anchor = AnchorStyles.None; // centers the legend in its parent
TableLayoutPanel legendPanel = new TableLayoutPanel();
legendPanel.AutoSize = true;
legendPanel.BackColor = System.Drawing.Color.LightGray;
legendPanel.Controls.Add(legend);
legendPanel.Dock = DockStyle.Bottom;
panel.Controls.Add(legendPanel);
}
}
#pragma warning restore 162
#endif
private void PostProcess()
{
// create a dependency graph between MethodInvokes
Dictionary <IVariableDeclaration, List <int> > mutationsOfVariable = new Dictionary <IVariableDeclaration, List <NodeIndex> >();
IndexedGraph g = new IndexedGraph(factorExprs.Count);
foreach (NodeIndex node in g.Nodes)
{
IExpression factor = factorExprs[node];
NodeInfo info = GetNodeInfo(factor);
for (int i = 0; i < info.arguments.Count; i++)
{
if (info.isReturnOrOut[i])
{
// this is a mutation. add to mutationsOfVariable.
IVariableDeclaration ivd = Recognizer.GetVariableDeclaration(info.arguments[i]);
if (ivd != null && CodeRecognizer.IsStochastic(context, ivd))
{
List <int> nodes;
if (!mutationsOfVariable.TryGetValue(ivd, out nodes))
{
nodes = new List <NodeIndex>();
mutationsOfVariable[ivd] = nodes;
}
nodes.Add(node);
}
}
}
}
foreach (NodeIndex node in g.Nodes)
{
IExpression factor = factorExprs[node];
NodeInfo info = GetNodeInfo(factor);
for (int i = 0; i < info.arguments.Count; i++)
{
if (!info.isReturnOrOut[i])
{
// not a mutation. create a dependency on all mutations.
IVariableDeclaration ivd = Recognizer.GetVariableDeclaration(info.arguments[i]);
if (ivd != null && CodeRecognizer.IsStochastic(context, ivd))
{
foreach (NodeIndex source in mutationsOfVariable[ivd])
{
g.AddEdge(source, node);
}
}
}
}
}
List <NodeIndex> topo_nodes = new List <NodeIndex>();
DepthFirstSearch <NodeIndex> dfs = new DepthFirstSearch <NodeIndex>(g.SourcesOf, g);
dfs.FinishNode += delegate(NodeIndex node)
{
IExpression factor = factorExprs[node];
ProcessFactor(factor, MessageDirection.Forwards);
topo_nodes.Add(node);
};
// process nodes forward
dfs.SearchFrom(g.Nodes);
// process nodes backward
for (int i = topo_nodes.Count - 1; i >= 0; i--)
{
NodeIndex node = topo_nodes[i];
IExpression factor = factorExprs[node];
ProcessFactor(factor, MessageDirection.Backwards);
}
}
