mvs is an implementation in the C++14 language of the algorithm described in Maximum Convex Subgraphs Under I/O Constraint for Automatic Identification of Custom Instructions for computing the maximum subgraphs of a directed acyclic graph under convexity, input and output constraints.
Install cmake and use the included CMake script to build mvs:
mkdir build
cd build
cmake <path/to/mvs>
cmake --build .
The resulting binary is named mvs. The compilation requires a system (mostly) compliant with the POSIX.1-2001 standard and a c++ compiler compatible with the C++14 standard.
mvs uses a superset of the DIMACS format as graph input format. An input file is a sequence of lines. The first line must be in the format
p convex NODES EDGES NAME FREQUENCY
where NODES and EDGES are the number of nodes and edges, respectively, NAME is the graph name, and FREQUENCY is an integer equal to the graph frequency, in the case of a data flow graph, and to 0 otherwise. The following lines can specify either edges or node attributes. A line with format
e U V
specifies an edge from node U to node V, where U and V are integers in the range [1, NODES]. A line with format
n U WEIGHT FORBIDDEN
specifies the attributes of node U, where WEIGHT is a real number defining the weight of U, and FORBIDDEN is 1 if U is a forbidden node and 0 otherwise.
mvs assumes that all the sources and sinks of the graph are forbidden nodes. The FORBIDDEN attribute can be used to mark additional nodes as forbidden.
mvs reads the input from standard input. The command
mvs MAX-IN MAX-OUT < FILE
enumerates the maximum convex subgraphs of the input graph with at most MAX-IN inputs and MAX-OUT outputs.
The output of mvs is in JSON format. mvs also logs to standard error various debug messages. They can be ignored by redirecting standard error to /dev/null. By default, mvs enumerates the maximum subgraphs with respect to the number of nodes. To enumerate the weighted maximum subgraphs use the -w option.
The mvs repository also contains the following files and directories:
- data
benchmark graphs in DIMACS format, DOT format and DOT JSON format. In the DOT formats, node objects have the additional attributes weight and forbidden, while graph objects have the additional attribute frequency.
- scripts/convert
script to convert a graph in DOT JSON format to DIMACS or DOT format. Usage:
convert --fmt dimacs FILE.json > FILE.dimacs
convert --fmt dot FILE.json > FILE.dot