numba-scfg

Numba compatible SCFG (Structured Control Flow Graph) utilities.

About

This repository contains Numba compatible utilities for working with SCFG (Structured Control FLow Graphs). SCFGs are a type of Intermediary Representation (IR) suitable for regularizing Python source and bytecode.

The code in this repository is an implementation of the CFG restructuring algorithms in Bahmann 2015, specifically those from section 4.1 and 4.2: namely "loop restructuring" and "branch restructuring". These are interesting for Numba because they serve to clearly identify regions within the Python source and bytecode.

Note: The project was previously known as numba-rvsdg and was renamed to numba-scfg in early 2025. The original scope was to implement Regional Value State Dependence Graphs (RVSDG), where SCFGs are necessary intermediary for the transformation from Python to RVSDG. Over time, it became evident that the SCFG transformations are important and reusable enough in their own right to warrant their own package and so this package was renamed.

Development

If you have make and conda available, a common setting up workflow could be:

$ make conda-env                        # setup conda environment
$ conda activate numba-scfg             # activate it
$ make conda-install                    # install dependencies
$ make                                  # lint, build and test the project

Feel free to look at the makefile for all development commands.

References

• Bahmann2015 -- https://dl.acm.org/doi/pdf/10.1145/2693261 -- Describes the transformation algorithms implemented

License

Copyright (c) 2022, Anaconda, Inc. All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.