The LLVM IR control flow graph can be visualized using the GraphViz tool. It gives a visual depiction of the nodes formed and how the code flow follows in the IR generated. Since the important data structures in LLVM are graphs, this can be a very useful way to understand the IR flow when writing a custom pass or studying the behavior of the IR pattern.
graphvizon Ubuntu, first add its
$ sudo apt-add-repository ppa:dperry/ppa-graphviz-test
$ sudo apt-get update
$ sudo apt-get install graphviz
If you get the
graphviz : Depends: libgraphviz4 (>= 2.18) but it is not going to be installed error, run the following commands: ...