Performance comparisons with benchcomp

While Kani includes a performance regression suite, you may wish to test Kani's performance using your own benchmarks or with particular versions of Kani. You can use the benchcomp tool in the Kani repository to run several 'variants' of a command on one or more benchmark suites; automatically parse the results of each of those suites; and take actions or emit visualizations based on those results.

Example use-cases

  1. Run one or more benchmark suites with the current and previous versions of Kani. Exit with a return code of 1 or print a custom summary to the terminal if any benchmark regressed by more than a user-configured amount.
  2. Run benchmark suites using several historical versions of Kani and emit a graph of performance over time.
  3. Run benchmark suites using different SAT solvers, command-line flags, or environment variables.


Benchcomp provides the following features to support your performance-comparison workflow:

  • Automatically copies benchmark suites into a fresh directories before running with each variant, to ensure that built artifacts do not affect subsequent runtimes
  • Parses the results of different 'kinds' of benchmark suite and combines those results into a single unified format. This allows you to run benchmarks from external repositories, suites of pre-compiled GOTO-binaries, and other kinds of benchmark all together and view their results in a single dashboard.
  • Driven by a single configuration file that can be sent to colleagues or checked into a repository to be used in continuous integration.
  • Extensible, allowing you to write your own parsers and visualizations.
  • Caches all previous runs and allows you to re-create visualizations for the latest run without actually re-running the suites.

Quick start

Here's how to run Kani's performance suite twice, comparing the last released version of Kani with the current HEAD.

git worktree add new HEAD
git worktree add old $(git describe --tags --abbrev=0)

tools/benchcomp/bin/benchcomp --config tools/benchcomp/configs/perf-regression.yaml

This uses the perf-regression.yaml configuration file that we use in continuous integration. After running the suite twice, the configuration file terminates benchcomp with a return code of 1 if any of the benchmarks regressed on metrics such as success (a boolean), solver_runtime, and number_vccs (numerical). Additionally, the config file directs benchcomp to print out a Markdown table that GitHub's CI summary page renders in to a table.

The rest of this documentation describes how to modify benchcomp for your own use cases, including writing a configuration file; writing a custom parser for your benchmark suite; and writing a custom visualization to examine the results of a performance comparison.