[Mlir-commits] [mlir] [mlir] Add first-class support for scalability in VectorType dims (PR #74251)

[Benjamin Maxwell]

MacDue wrote:

As a little summary this is what I'd like to solve:

- Safety
  - You have to specify a type of quantity in dim comparisons (fixed or scalable)
  - Can't forget to check the scalability of a dim (no implicit conversions, & can't forget to look at the `scalableDims` array)
  - Can't easily drop your `scalableDims` (they're safely stored in your `VectorDims`)
- Convenience & readability
  - It should not be harder for people writing scalable-aware code to do things correctly
    -  Standard handy iterators and utilities work with `VectorDims`
    -  Simple helpers inspecting/updating your vector dims 
  - It should be easy to read some code and see if it's doing the correct checks
    - Currently, when you do something like `getDimSize(0) == 1 && !getScalableDims()[0]`, it obscures that's checking for `VectorDim::getFixed(1)`

I don't think this is a complete solution, but I think it's a fairly non-invasive step towards something nicer :) 

https://github.com/llvm/llvm-project/pull/74251