Re: Zvediv extension discussions

Ken Dockser

Thanks folks, these are all very good points.

Earl: I absolutely agree that these extensions (like all RISC-V extensions) need to be developed based on real-world needs and need to be able to show their value (including utility and usability),  as well as value/cost ratio.

Guy: I agree that we need to look at the other leading architectures as we are well behind them in this area. We then need to come up with our own solutions that address the market needs and fit within the RISC-V approach and philosophy. 

Peter: Yes, we need to work to create extensions that take into account our future needs and intentions. In this case, where we are talking about adding instructions that improve matrix performance in the vector registers, we need to keep in mind how this might fit with future extensions that operate on matrices.

We still need to figure out how we can effectively and efficiently take this next step in RISC-V Vector.  It seems like the best approach would be to leverage the existing Vector TG by producing an updated charter that is focused on completing the Zvediv extension. Is this permitted/possible? Are the current Chair and Vice Chair amenable to this?


On Thu, Feb 3, 2022 at 10:11 PM Guy Lemieux <guy.lemieux@...> wrote:
The AMX extension for AVX512 is an interesting approach.... 

On Thu, Feb 3, 2022 at 8:02 PM Earl Killian <earl.killian@...> wrote:
I hope that these discussions will begin with algorithms and applications that need the additional performance, and proceed to analyze how proposed instructions address the greater need.

On Feb 3, 2022, at 14:45, Peter Lieber <peteralieber@...> wrote:

In the Graphics/ML SIG, we also discussed matrix operations as well.  We talked about a single matrix opcode with various functions like vector-matrix, matrix-matrix, and dot product functions, among others.  Just some initial ideas... 

The Zvediv extension would be a great start to get dimensionality to vectors, and we would want to keep matrices in mind when reviving the effort.

Peter Lieber

On Thu, Feb 3, 2022 at 2:17 PM Ken Dockser <kad@...> wrote:
I am hearing renewed interest in adding a dot-product extension to the RISC-V Vectors. This includes everything from adding a handful of FP and Int dot-product instructions all the way to completing the Zvediv extension.

What is the most efficient way to revive the efforts in these areas? Can we reconvene the Vector TG meetings?


Join { to automatically receive all group messages.