Add support for computing dispatch workgroup count using program slices. (#13038)

This PR changes the way the workgroup count calculation for dispatches are handled by default.

Previous approaches required to have context of what is put into a dispatch and what values are captured as workload. Managing this implicit link gets tricky. The approach in this PR assumes that all the information required for computing the number of workgroups is captured within the dispatch after the `flow.dispatch.workgroups` op is formed. In the backend, during tile and distribute a program slice is used to capture the computation that determines the number of workgroups, and is cloned into the workgroup count region.

One complication is that the signature of the `flow.dispatch.workgroups` operation is not preserved through the compilation pipeline. So in the backends it is not possible to connect the leaves of the slice back to the operands of the original `flow.dispatch.workgroups` operation that were captured as workload. To get around this, these operands are annotated within the dispatch with their position in the workload list.

Another side-effect of this change is that there is no need to instantiate `tensor.dim` operations to compute the workload. In dynamic shape cases, this leads to repeated instantiations of the same `tensor.dim` value leading to compile-time explosion even though these get CSE-ed away later.

To address the transform dialect path a new op transform.iree.populate_workgroup_count_region_using_num_threads_slice is s added that handles the workgroup count materialization for the transform dialect path. As a consequence

- `transform.iree.tile_to_forall_and_workgroup_count_region` is deprecated in favor of using `transform.structured.tile_to_forall` and the newly added transform dialect operation above.
- `transform.iree.convert_conv2d_to_img2col_and_adjust_workgroup_count_region` is also deprecated.

Fixes #11608
61 files changed
tree: ea83509447b45fa971a4382bf4cc18efc0f96d25
  1. .devcontainer/
  2. .github/
  3. benchmarks/
  4. build_tools/
  5. compiler/
  6. docs/
  7. experimental/
  8. integrations/
  9. lib/
  10. llvm-external-projects/
  11. runtime/
  12. samples/
  13. tests/
  14. third_party/
  15. tools/
  16. .bazel_to_cmake.cfg.py
  17. .bazelignore
  18. .bazelrc
  19. .bazelversion
  20. .clang-format
  21. .dockerignore
  22. .gitignore
  23. .gitmodules
  24. .pylintrc
  25. .style.yapf
  26. .yamllint.yml
  27. AUTHORS
  28. BUILD.bazel
  29. CITATION.cff
  30. CMakeLists.txt
  31. configure_bazel.py
  32. CONTRIBUTING.md
  33. LICENSE
  34. README.md
  35. WORKSPACE
README.md

IREE: Intermediate Representation Execution Environment

IREE (Intermediate Representation Execution Environment, pronounced as “eerie”) is an MLIR-based end-to-end compiler and runtime that lowers Machine Learning (ML) models to a unified IR that scales up to meet the needs of the datacenter and down to satisfy the constraints and special considerations of mobile and edge deployments.

See our website for project details, user guides, and instructions on building from source.

CI Status

Project Status

IREE is still in its early phase. We have settled down on the overarching infrastructure and are actively improving various software components as well as project logistics. It is still quite far from ready for everyday use and is made available without any support at the moment. With that said, we welcome any kind of feedback on any communication channels!

Communication Channels

Related Project Channels

  • MLIR topic within LLVM Discourse: IREE is enabled by and heavily relies on MLIR. IREE sometimes is referred to in certain MLIR discussions. Useful if you are also interested in MLIR evolution.

Architecture Overview

IREE Architecture IREE Architecture

See our website for more information.

Presentations and Talks

  • 2021-06-09: IREE Runtime Design Tech Talk (recording and slides)
  • 2020-08-20: IREE CodeGen: MLIR Open Design Meeting Presentation (recording and slides)
  • 2020-03-18: Interactive HAL IR Walkthrough (recording)
  • 2020-01-31: End-to-end MLIR Workflow in IREE: MLIR Open Design Meeting Presentation (recording and slides)

License

IREE is licensed under the terms of the Apache 2.0 License with LLVM Exceptions. See LICENSE for more information.