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composable_kernel/include/ck_tile
Kiefer van Teutem 9fe98c864f [CK Tile] Add Tile Distribution Encoding Calculator (#5515)
## Motivation

We want to be able to calculate TileDistributionEncodings describing
register mappings for any MmaOp. This is necessary for further
integration with CK Tile.

This MR adds a new struct TileDistrEncCalc, which takes an amdgcn_mma
type (MmaOp) and provides ABC warp distribution encodings for mapping
matrix fragment coordinates to register coordinates
(lane, vector item) and vice versa. It is able to take CTranpose,
Swizzle, and NumAccessA / NumAccessB template parameters for tweaking
the tile distributions. Swizzle modification will be implemented later.

The current implementation can deal with all intrinsic types and
block-hiding.

This MR also adds some additional static asserts and derived params
within amdgcn_mma_base, to enforce consistency and help calculate Tile
Distributions for block-hiding intrinsics.

An Example was added that uses the Tile Distr Enc Calc to calc and print
register layouts for Tile Distributions for some of our amdgcn_mma
structs. It also makes sure that the CTranspose modifier works as
intended.

Some additional gfx9 intrinsics were added to test block-hiding layouts
for the different types of C-block-hiding layouts.

The sparse intrinsic wrappers were updated according to Chris's recent
changes in another branch
(https://github.com/ROCm/rocm-libraries/pull/5508), which moved the
compression step outside of the intrinsic itself. This is necessary to
make sure that the Calculator can deal with this new interpretation of
the sparse intrinsics. I directly copied the new amdgcn structs from
Chris's branch and changed nothing else to avoid more complex merges in
the future. Note that this means I did not update a bunch of related
sparse code since that would be a lot, and therefore I disabled
test_amdgcn_sparse_mma for now.

The amdgcn_mma_layout test was refactored a bit:
- The old register mapping utility was removed and its use was replaced
by the new TileDistrEncCalc
- More tests were added to test layouts for different types of
block-hiding and sparse intrinsics
- The Selector method was removed and the tests were split up over
target architectures, with each target arch having a direct list of
amdgcn structs to be tested. This ensures that we force specific tests
on specific architectures and makes sure that the selector doesn't
quietly do some workarounds like creating compound intrinsics.

## Test Results

Layout tests based on calculated tile distribution encodings pass on all
architectures. Calculator works for all currently added amdgcn structs,
which includes different types of block-hiding and sparse intrinsics.
Printed layouts from new example verified by eye. CTranspose modifier
tested for large set of intrinsics.
2026-04-13 08:00:31 +00:00
..
2024-12-12 11:54:03 +08:00

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Composable Kernel Tile

concept

ck_tile provides a programming model with templated abstractions to enable users to implement performance-critical kernels for machine learning workloads. introduces following basic concepts to help users building your own operator

  • tensor coordinate transformation, this is the core concept of layout/index transform abstraction in both compiler time and run time.
  • tile-based programming model, including tile-level api and the concept of distributed tensor.

ck_tile is independently from the old ck, located under /include/ck_tile. You don't need to include anything from old CK, ck_tile has similiar (indeed almost the same) implementations for users to build operators. We will have a transition period to pull everything from old ck into ck_tile, stay tuned.

component

ck_tile is splitted into several componenets including core, host, ops/gemm, ops/fmha... each component you only need to include a single header (e.g #include "ck_tile/core.hpp", #include "ck_tile/ops/fmha.hpp") then you are able to use the function/structure inside (different from old ck)

[core]
ck_tile/core contains all the basic data structure and function to build the kernel, you can only include this header and build your own operators that utilizing all the basic building blocks introduced in ck.

core/container

  • array, store runtime variables with fixed length (tensor index, register buffer, etc...)
  • tuple, same as std::tuple, hold different type of data, and one of the solution to achieve multiple buffer.
  • sequence, compile time integer sequence used to build various internal structures, or to describe tile size
  • other convenient structure build on top of above 3

core/numeric

  • gpu data type like fp16_t, bf16_t, fp8_t... and the conversion between each other
  • constexpr integer similiar to std::integral_constant to be used as compile time integer.
  • math functions and numeric utilities

core/algorithm

  • coordinate transformation system, used to build tensor transform and compile time indexing. This is the core idea introduced in old ck to describe how a tensor is build by several basic transform primitives like merge/unmerge/embed etc... and how we indexing into a ND tensor that finally mapped to 1D memory offset.

core/tensor

  • tensor descriptor, to describe how a ND tensor
  • distributed tensor, describe the storage of this tensor, and the distribution of how a collection of threads collaborately work for this tensor.
  • tile level API, including load_tile, store_tile, shuffle_tile, slice_tile, etc...

[host]
ck_tile/host contains all the host side utilities to launch a kernel, create the device buffer, and some reference implementations. This can be used to create examples (like that under ck_tile example folder) and simple executable to invoke this kernel, so if you only need ck_tile to build your own device library then it's OK to not include this. Based on this, it is recommended to include the specific header you needed under this folder to avoid including unwanted headers (e.g, only include ck_tile/host/kernel_launch.hpp), unless you are writing a host executable.

[ops/gemm, ops/fmha, ops/reduce...]
our implementation of different device operators.

  • warp, warp tile level operator
  • block, block tile level operator
  • pipeline, pipeline that can achieve a customized tile level mainloop (or epilogue). By switching different pipeline to the kernel template you can have different kind of pipeline optimizations.
  • kernel, template interface for users to instantiate a particular kernel

[ops/epilogue]
epilogue part of our kernel. We may extend this epilogue part to let users to build their own cutomized epilogues.

[ref]
reference implementation of cpu or gpu. This folder is supposed to include a specific header on demand.

examples

currently we put all ck_tile related example under /example/ck_tile folder. Please check each example's subfolder.