Files
composable_kernel/example/ck_tile
John Afaganis 96c39b331e [rocm-libraries] ROCm/rocm-libraries#7829 (commit 13af7da)
[ck] Enforce ASCII-only C/C++ sources for hipRTC
 compatibility (#7829)
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Content-Type: text/plain; charset=UTF-8
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## Summary

CK source files must be compilable via **hipRTC (HIP runtime
compilation)**, whose preprocessor does not accept non-ASCII bytes
anywhere in a translation unit — **including in comments**. Bytes that
are harmless under `hipcc` (em-dashes, smart quotes, multiplication
signs, Greek letters, box-drawing glyphs, etc.) cause hipRTC to fail at
preprocessing time. These regularly leak in via LLM-assisted authoring
or copy/paste from formatted documents and silently break hipRTC paths
that are not exercised by the default `hipcc`-based build matrix.

This PR (a) cleans every existing violation (53 files) and (b) adds a
pre-checkin gate so new violations are rejected before merge.

## File extensions covered

Both the cleanup scan and the new Jenkins enforcement stage use the same
predicate:

```
*.h  *.hpp  *.cpp  *.h.in  *.hpp.in  *.cpp.in  *.inc  *.cl
```

(excluding `*/build/*` and `*/include/rapidjson/*`). This is a strict
superset of the existing `Clang Format` stage's predicate — `*.inc` is
added so test-fixture include files are also gated. The local pre-commit
hook's `c++/inc` type filter covers the same set.

## Why no enforcement today

CK is opted out of the rocm-libraries root `.pre-commit-config.yaml`, so
the existing `pre-commit` workflow doesn't touch CK. The local CK
`.pre-commit-config.yaml` only runs for developers who installed hooks.
The **authoritative gate is therefore the new Jenkins stage** in this
PR; the local hook is convenience.

## Commit layout (bisect-friendly)

1. `79798aa6261` — **`[ck] Convert reflect/ rendering to ASCII for
hipRTC compatibility`**
Behavior change, isolated. `TreeFormatter` swaps `├─ / └─ / │ ` for `|-
/ +- / | ` (3-col width preserved so alignment is unchanged).
`conv_description.hpp` swaps `×` for `x` as the dimension separator.
`test_conv_description.cpp` expected strings updated in lockstep so the
snapshot test stays green. This is the only commit in the series with
observable runtime impact.

2. `738fdb0d81c` — **`[ck] Strip non-ASCII bytes from C++ sources for
hipRTC compatibility`**
Mechanical text cleanup across 53 files. Replacements happen in comments
or in `std::cout` strings that are not asserted on by any test. None of
the 174 `.inc` files in the tree required edits, but they were in the
scan's predicate so the enforcement stage's predicate is a superset of
what was scanned. Full replacement table in the commit message.

3. `1d7cd8ba235` — **`[ck] Enforce ASCII-only C/C++ sources for hipRTC
compatibility`**
- New `projects/composablekernel/script/check_ascii_only.sh` (modeled on
`check_copyright_year.sh`).
- New entry in `projects/composablekernel/.pre-commit-config.yaml` under
the local-hooks block (`types_or: [c++, inc]`).
- New `ASCII Only Check` parallel stage in
`projects/composablekernel/Jenkinsfile`'s `Static checks` block,
mirroring the existing `Clang Format` stage but with `*.inc` added to
the find predicate. Always-on, no `RUN_CPPCHECK` gate.

The tree is buildable at every commit boundary. Commit 1 leaves 50 known
violations; commit 2 leaves 0; commit 3 wires the gate.

## Demo

Script output on a synthesized violation:

```
$ printf '// em-dash test \xe2\x80\x94 here\n' > /tmp/bad.cpp
$ projects/composablekernel/script/check_ascii_only.sh /tmp/bad.cpp
ERROR: /tmp/bad.cpp contains non-ASCII bytes:
1:// em-dash test — here
  Fix: replace with ASCII (em-dash -> --, smart quotes -> ", arrows -> ->, etc.)
$ echo $?
1
```

Full repo scan after the cleanup commits (note the `-name '*.inc'`
clause):

```
$ cd projects/composablekernel && find . -type f \( -name '*.h' -o -name '*.hpp' -o -name '*.cpp' \
    -o -name '*.h.in' -o -name '*.hpp.in' -o -name '*.cpp.in' -o -name '*.inc' -o -name '*.cl' \) \
    -not -path '*/build/*' -not -path '*/include/rapidjson/*' -print0 \
  | xargs -0 -P 8 -n 64 script/check_ascii_only.sh
$ echo $?
0
```

## Test plan

- [ ] Jenkins PR build: confirm new `Static checks -> ASCII Only Check`
stage runs green over the full predicate (incl. `*.inc`) and existing
`Clang Format` stage is unaffected.
- [ ] `test_conv_description` passes against the ASCII tree-formatter
output (touched in commit 1).
- [ ] Local: `pre-commit run ascii-only-checker --all-files` runs
cleanly after installing CK pre-commit hooks via
`script/install_precommit.sh`.
- [ ] Manually inject a non-ASCII byte in any `.cpp/.hpp/.inc` file,
push: confirm Jenkins fails the new stage with a clear error.
- [ ] Spot-check a representative subset of touched files under hipRTC
compilation to confirm no remaining hipRTC-blocking content (optional,
since the static byte check is a sufficient condition for hipRTC
preprocessor acceptance on this dimension).

🤖 Generated with [Claude Code](https://claude.com/claude-code)
2026-06-04 15:00:17 +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