Files
composable_kernel/example/ck_tile
root cb6fb2802d Split-KV codegen: dual-tile dispatch and head-merge for hdim=64
1. Dual-tile: add both bn0=64 (preferred) and bn0=32 (fallback) for
   hdim=64 on gfx9 and gfx12. The dispatch checks page_block_size %
   bn0 == 0 at runtime to select the optimal tile. bn0=64 halves KV
   iterations when page_block_size >= 64.

2. Tile dict now supports lists per hdim. The codegen loop iterates
   over all tile variants, generating separate kernel instances for
   each. Combine kernels are unaffected (tile-independent).

3. Enable kMergeNumHeadGroupsSeqLenQ for hdim=64 decode (previously
   hdim=128 only). For GQA-8 with max_seqlen_q=1, this packs 8 head
   groups into the M dimension. Only activates for no-mask instances
   (kernel static_assert requires !kHasMask).

4. Add qr (non-async) pipeline for fwd non-bias group mode as
   fallback after qr_async. The async pipeline on this branch has a
   kernel-level bug where fmha_fwd launches but writes no output.

Made-with: Cursor
2026-04-01 16:24:25 +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