[CK] Large tensor gemm workaround (#6761)
## Motivation
Customer qeruested large tensor gemm support for 8bit and 4bit data
types. Currently CK triggers “This GEMM not supported” error. The root
cause appears to be the 2 GB limit on the input/output matrix, triggered
by buffer offset constraints when testing a larger shape such as M =
699,904 (which is an exact multiple of MPerBlock = 256).
## Technical Details
Quick workaround to have support ASAP. Split the tensors into inputs /
outputs smaller than 2GB limit. Iterate on host and call all subproblems
without device code change.
Support is restricted to rowise layout in A, Ds and E
All changes were implemented in DeviceGemm structures to avoid secondory
affect on grouped convolutions.
Got lots of AI generated comments. Addressed the ones that seemed
relevant on the functionality.
## Test Plan
Within CK the following examples can be used with modified input sizes:
example_gemm_multiply_multiply_xdl_fp8
example_gemm_mx_fp4
Tested with Aiter tuning on provided shapes.
## Test Result
All gemms run and provide correct results.
## Submission Checklist
- [ ] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
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Co-authored-by: Zoltán Lakatos <zoltan.lakatos@streamhpc.com>
Co-authored-by: Márton Bidlek <marton.bidlek@streamhpc.com>
Co-authored-by: Adam Osewski <19374865+aosewski@users.noreply.github.com>