I’ve used a greedy approach in a JVM allocator once, which worked pretty well. Basically start at the top of a basic block with all values stored on the stack. Then just scan the instructions forward, maintaining a list of registers which contain a value, and whether the value is dirty (needs to be written … Read more
If I understood your question correctly, then a new edge (u,v) is only inserted if there was no path from v to u before (i.e., if (u,v) does not create a cycle). Thus, your graph is always a DAG (directed acyclic graph). Using Tarjan’s Algorithm to detect strongly connected components (http://en.wikipedia.org/wiki/Tarjan%27s_strongly_connected_components_algorithm) sounds like an overkill … Read more
From the source vertex, do a depth-first search along edges in the residual network (i.e., non-saturated edges and back edges of edges that have flow), and mark all vertices that can be reached this way. The cut consists of all edges that go from a marked to an unmarked vertex. Clearly, those edges are saturated … Read more
Graphviz itself provides a solution for rendering large graphs. Namely, Graphviz includes sfdp, a multiscale version of fdp (also in graphviz, similar to neato) for the layout of large undirected graphs which has been useful for drawing large graphs (70k nodes, 500k edges) in my project. You can find documentation for this software on the … Read more
I’m assuming you have a directed graph which you layout with dot. I don’t think there’s a magic switch to prevent overlapping edges. Graphviz tries to do that out of the box. Some suggestions that may help, depending on the graph: edge concentrators (concentrate=true): Merge multiple edges with a common endpoint into single edges, and … Read more