CompilerGym v0.1.8

This release introduces some significant changes to the way that benchmarks are managed, introducing a new dataset API. This enabled us to add support for millions of new benchmarks and a more efficient implementation for the LLVM environment, but this will require some migrating of old code to the new interfaces (see "Migration Checklist" below).

Highlights

Some of the key changes of this release are:

• [Core API change] We have added a Python Benchmark class (#190). The env.benchmark attribute is now an instance of this class rather than a string (#222).
• [Core behavior change] Environments will no longer select benchmarks randomly. Now env.reset() will now always select the last-used benchmark, unless the benchmark argument is provided or env.benchmark has been set. If no benchmark is specified, a default is used.
• [API deprecations] We have added a new Dataset class hierarchy (#191, #192). All datasets are now available without needing to be downloaded first, and a new Datasets class can be used to iterate over them (#200). We have deprecated the old dataset management operations, the compiler_gym.bin.datasets script, and removed the --dataset and --ls_benchmark flags from the command line tools.
• [RPC interface change] The StartSession RPC endpoint now accepts a list of initial observations to compute. This removes the need for an immediate call to Step, reducing environment reset time by 15-21% (#189).
• [LLVM] We have added several new datasets of benchmarks, including the Csmith and llvm-stress program generators (#207), a dataset of OpenCL kernels (#208), and a dataset of compilable C functions (#210). See the docs for an overview.
• CompilerEnv now takes an optional Logger instance at construction time for fine-grained control over logging output (#187).
• [LLVM] The ModuleID and source_filename of LLVM-IR modules are now anonymized to prevent unintentional overfitting to benchmarks by name (#171).
• [docs] We have added a Feature Stability section to the documentation (#196).
• Numerous bug fixes and improvements.

Migration Checklist

Please use this checklist when updating code for the previous CompilerGym release:

• Review code that accesses the env.benchmark property and update to env.benchmark.uri if a string name is required. Setting this attribute by string (env.benchmark = "benchmark://a-v0/b") and comparison to string types (env.benchmark == "benchmark://a-v0/b") still work.
• Review code that calls env.reset() without first setting a benchmark. Previously, calling env.reset() would select a random benchmark. Now, env.reset() always selects the last used benchmark, or a predetermined default if none is specified.
• Review code that relies on env.benchmark being None to select benchmarks randomly. Now, env.benchmark is always set to the previously used benchmark, or a predetermined default benchmark if none has been specified. Setting env.benchmark = None will raise an error. Select a benchmark randomly by sampling from the env.datasets.benchmark_uris() iterator.
• Remove calls to env.require_dataset() and related operations. These are no longer required.
• Remove accesses to env.benchmarks. An iterator over available benchmark URIs is now available at env.datasets.benchmark_uris(), but the list of URIs cannot be relied on to be fully enumerable (the LLVM environments have over 2^32 URIs).
• Review code that accesses env.observation_space and update to env.observation_space_spec where necessary (#228).
• Update compiler service implementations to support the updated RPC interface by removing the deprecated GetBenchmarks RPC endpoint and replacing it with Dataset classes. See the example service for details.
• [LLVM] Update references to the poj104-v0 dataset to poj104-v1.
• [LLVM] Update references to the cBench-v1 dataset to cbench-v1.