Files
composable_kernel/include/ck_tile
Anton Gorenko 8118d84f77 [CK_TILE] Support f32 in FMHA (fwd and bwd) (#2836)
* Support 16x16 (MFMA, WMMA) and 32x32 (MFMA) tiles in fwd and bwd BlockDropout

Add comments with dropout implementation details

Fix performance regression of fwd+dropout

    * Remove some usage of type punning (reinterpret_cast with ref or ptr) in Philox;
    * "scalarize" seed and offset, they may come either from kernel args or from device memory
      (presumably loaded with vector loads).

    These changes help the compiler to procude more optimal code and reduce register spilling.

Use WarpGemmDispatcher instead of explicit WarpGemmMfma... to get  CWarpDstrEncoding

Use code based on BlockDropout in BlockDropoutBwd

Refactor BlockDropout (fwd)

Implement BlockDropout (fwd) for WMMA

    Originally BlockDropout only supported 32x32 tiles (IsWG32 = true),
    this version supports 16x16 tiles.
    If MPerBlock > MWarp * 16, it can generate numbers for two 16x16 tiles, similarly
    to BlockDropoutBwd.

Implement BlockDropoutBwd for WMMA

Remove MakeRandValLds* functions unused in BlockDropoutBwd

Remove unused Run overload from BlockDropoutBwd

* Fix regression with philox seed and offset when they exceed 32-bit int

__builtin_amdgcn_readfirstlane works with 32-bit values, seed and offset
are 64-bit so they get truncated.

* Add F32 MFMA warp gemms

* Support f32 in fwd FMHA

* Implement transpose_vectors for 4-byte types (float)

* Fix unexpected implicit f32->uint32 cast in buffer_store<4>

__builtin_amdgcn_raw_buffer_store_b32 expects unsigned int but float was passed (implicitly casted to uint).
mbuf_t types in other buffer_store<> are changed for consistency.

* Support F32 in bwd FMHA

hdim = 256 is disabled for now because it uses too much memory on gfx90a

* Support Headdim = 48 (divisible by 16) in fwd

* Add fp32-specific receipts (800 and 801)

* Tune fwd tiles

* Tune bwd tiles

* Use small tiles only for small seqlen_q

* Fix after rebasing

* Fix selection of a fallback tile based on bm0

The assumption that the largest bm0 == 128 is not always true for
current fp32 tiles.

* Remove constraints and adjust filtering for fp32

Custom constraints are no longer needed because now the smallest tile
is selected automtically based on seqlen_q.
Filters related to qr_async_trload disabled valid fp32 tiles.

* Add fp32 tests

* Make splitkv and appendkv compile for fp32 only

There are no instances yet, but API still must compile when only fp32 is
requested.

* Remove unimportant f32 instances

* Add test_ck_tile_fmha_*_fp32 to REGRESSION_TESTS

* Replace magic numbers with a constant, improve comments for dropout

* Update changelog

* Fix condition that dq_acc must be set to zero when mask is used

The change was introduced in #2799

* Replace warp_uniform with recently added amd_wave_read_first_lane

* Add hdim = 96 and 192 to fwd

[ROCm/composable_kernel commit: 1edd250115]
2025-09-27 18:03:48 +05:00
..
2025-09-10 08:06:14 +05:00
2024-12-12 11:54:03 +08:00

Back to the main page

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.