commit 1a635643583e8787030b9fe57fae5d0543644f65
author Benjamin Maxwell <benjamin.maxwell@arm.com> Thu Sep 28 19:00:55 2023 +0100
committer GitHub <noreply@github.com> Thu Sep 28 11:00:55 2023 -0700
tree a8eddb83c1d3f8c3520e84cccf74d01bdacadeb9
parent 15ace7e2f687cbf5c7821cbb7f28e95a604452a2

Refactor IREECodegenAttrs to use typed array parameters (#15032)

This reworks the attributes in IREECodegenAttrs so that typed [Optional]ArrayRefParameters are used instead of untyped ArrayAttrs.

Doing this removes the manual type-checking and manual conversions to/from SmallVector<T>.

This did require a small restructuring of the lowering_config attribute, so instead of having multiple nested arrays IntegerAttrs for tiling levels, it now has one array of TilingLevelAttrs. The TilingLevelAttr then contains the tile sizes and tile interchange values for a particular level.

The TilingLevelAttr has a custom assembly format that keeps its syntax as close as possible to the previous syntax, to avoid as much test churn as possible. We plan to follow up this patch with another change that extends the TilingLevelAttr to support scalable sizes (using the canonical MLIR syntax), which will need a custom parser anyway, so we don't see this as a dealbreaker.

Example configs:

```
// No tile interchange (no change in syntax)
#iree_codegen.lowering_config<tile_sizes = [[2, 64, 64, 64],
                                            [1, 1, 1, 4],
                                            [0, 0, 0, 0]]>
// With tile interchange
// Before:
#iree_codegen.lowering_config<
   tile_sizes = [[32, 64, 0], [8, 32, 0], [0, 0, 16]],
   tile_interchange = [[1, 0, 2], [], []]>

// After:
#iree_codegen.lowering_config<tile_sizes = [
   {sizes=[32, 64, 0], interchange=[1, 0, 2]}, [8, 32, 0], [0, 0, 16]]>
```

---

These changes makes the `lowering_config` easier to extend for a follow on patch that starts adding scalable tile sizes.