fd3907ccb5
Reland #118503. Added a fix for builds with `-DBUILD_SHARED_LIBS=ON` (see last commit). Otherwise the changes are identical. --- ### New API Previous discussions at the LLVM/Offload meeting have brought up the need for a new API for exposing the functionality of the plugins. This change introduces a very small subset of a new API, which is primarily for testing the offload tooling and demonstrating how a new API can fit into the existing code base without being too disruptive. Exact designs for these entry points and future additions can be worked out over time. The new API does however introduce the bare minimum functionality to implement device discovery for Unified Runtime and SYCL. This means that the `urinfo` and `sycl-ls` tools can be used on top of Offload. A (rough) implementation of a Unified Runtime adapter (aka plugin) for Offload is available [here](https://github.com/callumfare/unified-runtime/tree/offload_adapter). Our intention is to maintain this and use it to implement and test Offload API changes with SYCL. ### Demoing the new API ```sh # From the runtime build directory $ ninja LibomptUnitTests $ OFFLOAD_TRACE=1 ./offload/unittests/OffloadAPI/offload.unittests ``` ### Open questions and future work * Only some of the available device info is exposed, and not all the possible device queries needed for SYCL are implemented by the plugins. A sensible next step would be to refactor and extend the existing device info queries in the plugins. The existing info queries are all strings, but the new API introduces the ability to return any arbitrary type. * It may be sensible at some point for the plugins to implement the new API directly, and the higher level code on top of it could be made generic, but this is more of a long-term possibility.
The LLVM/Offload Subproject
The Offload subproject aims at providing tooling, runtimes, and APIs that allow users to execute code on accelerators or other "co-processors" that may or may not match the architecture of their "host". In the long run, all kinds of targets are in scope of this effort, including but not limited to: CPUs, GPUs, FPGAs, AI/ML accelerators, distributed resources, etc.
For OpenMP offload users, the project is ready and fully usable. The final API design is still under development. More content will show up here and on our webpage soon. In the meantime, people are encouraged to participate in our meetings (see below) and check our development board as well as the discussions on Discourse.
Meetings
Every second Wednesday, 7:00 - 8:00am PT, starting Jan 24, 2024. Alternates with the OpenMP in LLVM meeting. invite.ics Meeting Minutes and Agenda