Files
composable_kernel/example/ck_tile
Yi DING b09112bbad [rocm-libraries] ROCm/rocm-libraries#4577 (commit a36922c)
[CK_TILE] FMHA BWD Launcher Interface

## Motivation
Reduce memory usage; Be prepared to implement optimizations of reducing
nsplits in deterministic cases.

## Technical Details
This PR introduces a new launcher interface for the FMHA backward
operation, replacing direct function calls with a more structured
approach. The launcher encapsulates kernel dispatch logic and provides
access to computed metadata like the number of dQ acc splits.

**Changes:**
- Added `fmha_bwd_launcher` class that wraps kernel execution and
exposes `dq_acc_splits`
- Moved `fmha_bwd_traits` construction earlier in the execution flow to
support launcher initialization
- Refactored code generation to produce both legacy API and new launcher
constructor

## Test Plan

<!-- Explain any relevant testing done to verify this PR. -->

## Test Result

<!-- Briefly summarize test outcomes. -->

## Submission Checklist

- [x] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
2026-03-04 01:21:07 +00:00
..

CK Tile Example Suite

This directory contains a comprehensive suite of examples demonstrating the CK Tile programming model for high-performance GPU kernels. Each example illustrates a key deep learning or HPC operation, implemented using tile-based parallelism, modular pipelines, and data movement policy.


What is CK Tile?

CK Tile is a composable GPU programming API that expresses kernels as a composition of "tiles"—rectangular blocks of computation and data movement. The pipeline & policy orchestrates data movement (global <-> LDS <-> registers), computation, and synchronization, enabling high efficiency and flexibility.


Example Index

Example Operation Description
01_fmha Fused Multi-Head Attention Tile-based FMHA with masking, quantization, and epilogue fusion
02_layernorm2d LayerNorm2D Blockwise layer normalization with fusion and quantization
03_gemm GEMM Matrix multiplication with tilewise parallelism
04_img2col im2col Image-to-column transformation for GEMM-based convolution
05_reduce Reduction Tilewise sum, max, mean reductions
06_permute Permute Generic tensor permutation (up to rank-8)
09_topk_softmax TopK-Softmax Rowwise softmax and top-k selection for MoE gating
10_rmsnorm2d RMSNorm2D Root mean square normalization for LLMs
11_add_rmsnorm2d_rdquant Add + RMSNorm2D + RDQuant Fused add, RMSNorm, and rowwise dynamic quantization
12_smoothquant SmoothQuant Per-channel scaling and quantization for int8 inference
13_moe_sorting MoE Sorting Token-to-expert rearrangement for MoE dispatch
14_moe_smoothquant MoE-SmoothQuant Expert-dependent quantization fused with top-k selection
15_fused_moe Fused MoE End-to-end fused MoE block: sorting, group-GEMM, activation, weighting
16_batched_gemm Batched GEMM Parallel computation of multiple GEMMs
17_grouped_gemm Grouped GEMM Multiple independent GEMMs with different shapes
18_flatmm FLATMM Flattened matrix multiplication for packed layouts
19_gemm_multi_d Multi-D GEMM GEMM with multiple side inputs (bias, residual, etc.)
35_batched_transpose Batched Transpose NCHW <-> NHWC and other layout conversions
36_copy Copy Minimal example for tile-based memory movement
37_transpose Block Transpose High-performance tiled transpose for large tensors

Technical Highlights


How to Build & Run

mkdir build && cd build
sh ../script/cmake-ck-dev.sh ../ <arch>
make -j

Each example produces its own executable in build/bin/.


Learning and Extending


References


Back to Composable Kernel Examples