## Summary ### Rationale `ck_tile::sequence` is the most fundamental metaprogramming type in ck_tile — it underpins tensor dimensions, strides, loop bounds, and index calculations. Six of its metafunctions use recursive template instantiation, producing O(N) to O(N²) intermediate types that the compiler must process. When these are used inside deeply nested GEMM pipelines with large dimension counts, the cumulative instantiation overhead becomes a significant contributor to frontend compile time. Measurements on `test_gemm_pipeline_compv6` show 84,288 `InstantiateFunction` calls in the frontend alone. Reducing template instantiation depth in these core utilities has a multiplicative effect because they are called from hundreds of sites. ### What changed | Metafunction | Before | After | |---|---|---| | `sequence::modify` | O(N) recursive split/merge | O(1) pack expansion | | `sequence_gen` | O(log N) recursive binary split | O(1) via `__make_integer_seq` | | `uniform_sequence_gen` | Delegates to `sequence_gen` | O(1) via `__make_integer_seq` | | `sequence_reverse_inclusive_scan` | O(N) recursive | O(1) constexpr for-loop + pack expansion | | `sequence_inclusive_scan` | Computed via reverse + flip | O(1) constexpr for-loop (unified impl) | | `sequence_exclusive_scan` | O(N) recursive merge chain | O(1) constexpr for-loop + pack expansion | | `sequence_map_inverse` | O(N²) recursive modify calls | O(1) constexpr for-loop + pack expansion | Supporting changes: - Portable `__type_pack_element` fallback with `__has_builtin` guard (hipRTC-safe, no `<tuple>` dependency) - Renamed reserved `__integer_sequence` to `integer_sequence_wrapper` - Adopted `static_array` from develop (PR #4355) for constexpr computation - Unified forward and reverse inclusive scan into a single `sequence_inclusive_scan_impl` with `bool Reverse` template parameter - Added `sequence_inclusive_scan` struct (new public API for forward scan direction) - Replaced recursive `sequence_exclusive_scan` (3 template specializations) with `sequence_exclusive_scan_impl` using the same constexpr for-loop pattern as inclusive scan - Rewired `exclusive_scan_sequence` and `prefix_sum_sequence` to use new impl - Added `CK_TILE_HOST_DEVICE` to `exclusive_scan_sequence` and `prefix_sum_sequence` to match sibling scan function annotations ### Technical debt and housekeeping - Unified all `namespace impl` to `namespace detail` across sequence.hpp for consistency - Removed dead comment block (orphaned `integer_sequence` alternative) - Added defensive `static_assert(sizeof...(Is) > 0)` in `sequence_map_inverse::build_inverse` - Converted all multi-line Doxygen blocks from `///` to `/** */` per style guide - Corrected `constexpr static` to `static constexpr` keyword ordering in `static_array` - Added blank line between `#pragma once` and first `#include` in `static_array.hpp` - Trimmed redundant 4-line comment on `sequence_gen_helper` to a one-liner - Moved `sequence_gen` Doxygen comment below `namespace detail` block so it directly precedes the struct it documents - Added Doxygen `@brief`/`@tparam`/`@pre` documentation for `sequence_gen` and `sequence_map_inverse` public APIs - Added `@brief` documentation to `static_array` explaining relationship to `ck_tile::array` - Added scope comment at `namespace detail` openings **Note:** `private:`/`public:` access modifier indentation is enforced at 4 spaces by `.clang-format`. The style guide calls for left-alignment, but the formatter overrides this. Requires a `.clang-format` config change to resolve — not addressable in code. ### `static_array` hardening (from develop's PR #4355) - Added zero-length array guard (`T elems[N > 0 ? N : 1]`) - Added `CK_TILE_HOST_DEVICE` annotations to `operator[]` and `size()` - Added `#include "ck_tile/core/config.hpp"` (IWYU for `CK_TILE_HOST_DEVICE`) ### Value Combined with the `static_ford` changes, measured impact on `test_gemm_pipeline_compv6`: - **Frontend: -28.9%** (InstantiateFunction: 84,288 → 69,439) - **Backend: -13.1%** (CodeGen Functions: 3,170 → 2,203) - **Wall-clock: -16.3%** (611.6s → 512.2s) ### Files changed (4) - `sequence.hpp`: Metafunction optimizations, namespace unification, documentation, style fixes - `static_array.hpp`: Zero-length guard, `CK_TILE_HOST_DEVICE`, documentation, style fixes - `test_sequence.cpp`: 50 unit tests with runtime `EXPECT_EQ` assertions (new file) - `CMakeLists.txt`: Register new test target ## Test plan - [x] 50 runtime unit tests covering all optimized and pre-existing sequence APIs - [x] Edge cases: empty sequences, single-element, larger sizes (N=8), negative values, non-trivial init values - [x] Both functor signatures tested (`operator()(index_t)` and `operator()(number<I>)`) - [x] Both scan reducers (`plus`, `multiplies`) with forward, reverse, inclusive, and exclusive directions - [x] Exclusive scan: sum, product, single, empty, non-zero init - [x] Prefix sum: N+1 output verification, single, empty - [x] Permutation round-trip verification for `sequence_map_inverse` - [x] Full sequence public API coverage: modify, gen, uniform_gen, scans (inclusive, exclusive, prefix sum), map_inverse, make_index_sequence, size/sum/product, push/pop, reverse, extract, merge, arithmetic operators, equality, transform - [x] Portable `__type_pack_element` fallback tested implicitly (same `at_index_t` interface) 🤖 Generated with [Claude Code](https://claude.com/claude-code) ## Submission Checklist - [ ] Look over the contributing guidelines at https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests. --------- Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com> Co-authored-by: Max Podkorytov <4273004+tenpercent@users.noreply.github.com>
CK Tile Testing Guide
This document describes the test organization and available test targets for CK Tile operations.
Overview
CK Tile tests are organized with multiple levels of granularity to support different development workflows:
- Global test labels - Run tests across all operations
- Operation-specific umbrella targets - Run all tests for a specific operation
- Individual test executables - Run specific tests
Global Test Labels
These targets run tests across all CK operations (not just CK Tile):
ninja smoke
Run fast smoke tests (tests that complete within ~30 seconds on gfx90a).
ninja smoke
ninja regression
Run slower, more comprehensive regression tests.
ninja regression
ninja check
Run ALL available tests in the entire codebase.
ninja check
Operation-Specific Umbrella Targets
These targets allow you to run all tests for a specific CK Tile operation. This is useful when making changes to a particular operation and wanting to validate all related tests without running the entire test suite.
GEMM Operations
ck_tile_gemm_tests
Run all basic GEMM pipeline tests (memory, compute variants, persistent, etc.)
ninja ck_tile_gemm_tests
Test executables included:
test_ck_tile_gemm_pipeline_memtest_ck_tile_gemm_pipeline_compv3test_ck_tile_gemm_pipeline_compv4test_ck_tile_gemm_pipeline_persistenttest_ck_tile_gemm_pipeline_compv6test_ck_tile_gemm_pipeline_comp_async(gfx95 only)test_ck_tile_gemm_pipeline_*_wmmavariants (gfx11/gfx12 only)
ck_tile_gemm_block_scale_tests
Run all GEMM tests with block-scale quantization (AQuant, BQuant, ABQuant, etc.)
ninja ck_tile_gemm_block_scale_tests
Test executables included: 29 test executables covering:
- AQuant tests (memory pipelines, base layouts, prefill, preshuffle, transpose)
- ABQuant tests (base, padding, preshuffle)
- BQuant tests (1D/2D variants, transpose)
- BQuant with PreshuffleB (decode/prefill, 1D/2D)
- BQuant with PreshuffleQuant (decode/prefill, 1D/2D)
- RowColQuant and TensorQuant tests
ck_tile_gemm_streamk_tests
Run all GEMM StreamK tests (tile partitioner, reduction, smoke, extended)
ninja ck_tile_gemm_streamk_tests
Test executables included:
test_ck_tile_streamk_tile_partitionertest_ck_tile_streamk_reductiontest_ck_tile_streamk_smoketest_ck_tile_streamk_extended
ck_tile_grouped_gemm_quant_tests
Run all grouped GEMM quantization tests
ninja ck_tile_grouped_gemm_quant_tests
Test executables included:
test_ck_tile_grouped_gemm_quant_rowcoltest_ck_tile_grouped_gemm_quant_tensortest_ck_tile_grouped_gemm_quant_aquanttest_ck_tile_grouped_gemm_quant_bquanttest_ck_tile_grouped_gemm_quant_bquant_preshuffleb
Other Operations
ck_tile_fmha_tests
Run all FMHA (Flash Multi-Head Attention) tests
ninja ck_tile_fmha_tests
Test executables included: Forward and backward tests for fp16, bf16, fp8bf16, fp32
ck_tile_reduce_tests
Run all reduce operation tests
ninja ck_tile_reduce_tests
Test executables included:
test_ck_tile_reduce2dtest_ck_tile_multi_reduce2d_threadwisetest_ck_tile_multi_reduce2d_multiblock
Individual Test Executables
You can also build and run individual test executables:
Build a specific test
ninja test_ck_tile_gemm_pipeline_mem
Run a specific test directly
./build/bin/test_ck_tile_gemm_pipeline_mem
Run a specific test through ctest
ctest -R test_ck_tile_gemm_pipeline_mem --output-on-failure