mirror of
https://github.com/ROCm/composable_kernel.git
synced 2026-04-19 14:29:05 +00:00
144854dba1
[CK_TILE] Optimize static_ford and sequence compile-time infrastructure (#5938) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ## Problem Each `static_for<0, N, 1>` instantiates its lambda N times (one per `number<I>` type). When nested, intermediate lambdas capture the outer loop variable (a different type per iteration), creating unique closure types. For a 3-level nest with M=4, N=4, K=2, this produces 4 + 16 + 32 = 52 IR functions, of which 20 are intermediate closures that get inlined away but still cost frontend compile time. ck_tile's `static_ford` was supposed to eliminate these intermediates (as old CK's PR #5031 did successfully), but it used a **recursive** `static_ford_impl` that recreated the same closure pattern plus added `reorder_old_to_new`/`reorder_new_to_old` overhead. Additionally, the sequence utility layer (`sequence_sort`, `is_valid_sequence_map`) used recursive template metaprogramming that generated O(N log N) intermediate types for every permutation validation — called on every `reorder_new_to_old`/`reorder_old_to_new` invocation. ## Changes ### 1. Replace `sequence_sort` with constexpr insertion sort Replace recursive merge sort (`sequence_sort_impl` + `sorted_sequence_merge_impl`, O(N log N) intermediate type instantiations) with constexpr insertion sort using `static_array`. O(1) template depth, same `::type` and `::sorted2unsorted_map` API. ### 2. Replace `is_valid_sequence_map` with constexpr check Replace sort-based permutation validation (which instantiated the full `sequence_sort` chain) with a constexpr "seen array" loop. O(N) constexpr steps instead of O(N log N) template instantiations. ### 3. Replace recursive `static_ford` with flat-loop `index_decomposer` Replace `static_ford_impl` (recursive `static_for` nesting + `pop_front`/`push_back` + `reorder_old_to_new` per iteration) with flat `index_decomposer` using pre-computed strides. Add `decompose_reordered` alias that folds reordering into decomposition, and `inverse_perm` helper that avoids the `sequence_map_inverse` → `is_valid_sequence_map` → `sequence_sort` chain. ### 4. Eliminate internal lambda via `ford_applier` The flat-loop approach still used `static_for` with a lambda, creating M×N internal lambda instantiations per call site. Replace with `ford_applier` struct that calls `f(decompose<I>{})` directly via fold expression — zero intermediate closures: ```cpp // Before: 2×M×N function instantiations static_for<0, M*N, 1>{}([&](auto i) { f(decompose<i>{}); }); // After: M×N function instantiations (50% reduction) ford_applier<Decomposer, make_index_sequence<M*N>>{}(f); ``` Also unified identity and non-identity order paths into a single template with `constexpr if`. ### 5. Fix const-qualified sequence handling Fix `is_valid_sequence_map` to handle const-qualified sequence types via `remove_cvref_t` in callers (`tensor_adaptor.hpp`, `tile_distribution_encoding.hpp`). ## Results (this PR only, without flattening) ### Build Time (Wilcoxon signed-rank, 7 paired trials, gfx942, load ~5) | Target | Base (s) | Treat (s) | Delta | % | Wins | Significant? | |--------|----------|-----------|-------|---|------|-------------| | **flatmm** | 160.1 | 152.7 | **-7.4s** | **-4.6%** | 6/7 | **YES** (W+=1, p<0.05) | | universal_gemm | 228.4 | 224.7 | -3.7s | -1.6% | 6/7 | Trending (W+=4) | Per-trial diffs (flatmm): [-6, -20, -9, -8, -8, 4, -5] Per-trial diffs (universal_gemm): [-2, -6, 4, -3, -2, -11, -6] ### IR Function Counts (device trace, gfx942) | Target | Metric | Before | After | Delta | % | |--------|--------|--------|-------|-------|---| | **universal_gemm** | InstantiateFunction | 117,715 | 109,165 | **-8,550** | **-7.3%** | | **universal_gemm** | CodeGen Function | 47,912 | 45,044 | **-2,868** | **-6.0%** | | **flatmm** | InstantiateFunction | 100,939 | 95,127 | **-5,812** | **-5.8%** | | **flatmm** | CodeGen Function | 42,651 | 40,367 | **-2,284** | **-5.4%** | Note: The `ford_applier` (commit 3) has minimal additional effect in this PR since ck_tile code does not yet use `static_ford` extensively. Its impact compounds when the follow-up flattening PR #5939 converts 124 `static_for` nests to `static_ford`. Combined results with #5939: flatmm **-7.5%** wall time (p<0.01), CodeGen **-10.5%**. ### ASM Equivalence 7/7 PASS — 979,943 lines of device assembly verified identical (gfx942 + gfx1100). TUs: universal_gemm, flatmm_basic, fmha_bwd, reduce, bscale. ## Test plan - [x] `test_ck_tile_static_ford`: 13 behavioral tests (identity/non-identity orders, 1D-4D, unit dimensions, edge cases) - [x] `ck_tile_unit_sequence`: 88 tests (11 new for sorted2unsorted_map, is_valid_sequence_map edge cases, sequence_unique_sort map round-trip) - [x] ASM equivalence verified (980K lines) - [x] Wilcoxon timing verified (7 trials, flatmm p<0.05) - [ ] CI 🤖 Generated with [Claude Code](https://claude.com/claude-code)
12 lines
361 B
CMake
12 lines
361 B
CMake
# Copyright (c) Advanced Micro Devices, Inc., or its affiliates.
|
|
# SPDX-License-Identifier: MIT
|
|
|
|
message("-- Adding: test/ck_tile/utility/")
|
|
|
|
add_gtest_executable(test_fill test_fill.cpp)
|
|
add_gtest_executable(test_ck_tile_sequence test_sequence.cpp)
|
|
add_gtest_executable(test_ck_tile_static_ford test_static_ford.cpp)
|
|
|
|
# Add print tests
|
|
add_subdirectory(print)
|