manupa-arm commented on a change in pull request #22: URL: https://github.com/apache/tvm-rfcs/pull/22#discussion_r699187806
########## File path: rfcs/0022-tir-non-scalar-constants.md ########## @@ -0,0 +1,107 @@ + +- Feature Name: tir_non_scalar_constants +- Start Date: 2021-06-01 +- RFC PR: https://github.com/apache/tvm-rfcs/pull/22 +- GitHub Issue: TBD + +# 1. Summary + +This RFC proposes how non-scalar constants could be represented in TIR and used by passes in the lowering process. + +# 2. Motivation + +Currently, the non-scalar constants could be represented in Relay (relay.Constant) to be used by relay passes but not in TIR. Therefore, when performing lowering using TIR passes, we have to maintain a side-channel of tir::Var to constant non-scalar data mapping to perform transformations that could use the knowledge where some of the data are constants. + +Few example scenarios as further motivation : + +## Weight compression + +When lowering for accelerators (E.g. : [Arm(R) Ethos(TM)-U NPU](https://github.com/apache/tvm-rfcs/pull/11)), certain operations will need to get tiled to co-optimize performance and memory utilization. Such tiling patterns create slices of weights that need compressing that will end up with varying sizes. Therefore, the knowledge of some tir::Vars refer to constants are critical in the level of TIR to perform this. Review comment: @junrushao1994 , the values do matter, as with compression the entropy of the constant data information determines the size post-compression. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@tvm.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
