commit c54764e8dffa9e02c03ba28f28ccbdbc3504fd2b
author Quinn Dawkins <quinn.dawkins@gmail.com> Fri Dec 12 09:24:56 2025 -0800
committer GitHub <noreply@github.com> Fri Dec 12 12:24:56 2025 -0500
tree 77b6ee13b86b2dde57c5c8caed224c7ccdee44f0
parent 5ed90416b82523b26d0d8fdc9919a25a30ea5fad

[Codegen] Add PCF dialect (#22804)

This introduces a new dialect for "Parallel Control Flow" (named a la
scf). This is motivated by expressivity gaps in the current constructs
we use to represent distributed compute for the next set of algorithms
we're working towards supporting in the compiler. To name a few:
 - Stream-K
 - Warp/Clustered reductions
 - Named Barriers
 - Improved robustness of fusion support
 - Persistent-ish kernels (things that need to communicate across wkgps)

Naturally the base added here does not directly cover all of the above
but should make it much easier to do so. The core idea behind the
dialect hinges on three concepts:
1. Shaped references of unspecified layout and memspace
2. Execution scopes which threads are forked out of
3. Synchronization scopes which control access to associated memory

The dialect includes further documentation behind the above 3 points.

The initial proposal can be found here:
https://hackmd.io/iHdqgU7MQnSvX6H_y_6JrQ (Much of the
naming/representation has changed since this writeup)