[CK_TILE] Rename Stream-K grid function
## Motivation
This PR introduces a change in the name of the get_grid function in the
Stream-K TilePartitioner to avoid confusion with a similarly named
method. In the Stream-K TilePartitioner, there is get_grid() which
returns num_cu*occupancy and there is grid_size() which returns the grid
size used to launch the kernel. In this PR, we change get_grid() to be
get_max_active_wgs() to better reflect what the function returns and not
confuse it with grid_size().
## Technical Details
Initially in the Stream-K TilePartitioner we had get_grid() which
returned grid_. We are renaming get_grid() to get_max_active_wgs() and
grid_ to max_active_wgs_ internally, while keeping grid_size() the same.
The parameter, grid, for the Stream-K TilePartitioner remains the same
to maintain consistency with the rest of the Stream-K API.
## Test Plan
Validated using the test suite that is already present.
## Test Result
All tests passed
## Submission Checklist
- [x] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
[CK_TILE] Reduce Register Spills in Stream-K Reductions
(#4984)
## Motivation
In CK Tile Stream-K, kernels using one of two non-atomic reduction
strategies (i.e., linear, tree) have high register spill count, with the
tree reduction generally being worse. These changes act a first step to
help decrease the register spill count.
## Technical Details
### Problem 1: Unvectorized access to partials
In both the linear and tree reductions, workgroups write partials
results to a global buffer; another workgroup will later read this data.
When the initial logic to support reading and writing to the partials
buffer was added (see
https://github.com/ROCm/composable_kernel/pull/3107), the tile
distribution encoding used to read from and write to partials matches
the register layout for the accumulator of the mfma instruction used for
the kernel. Since we do not currently use the transposed register layout
for the accumulator, we end with an encoding that is not optimized for
writing to HBM.
For example: Consider the register layout of the
`v_mfma_f32_16x16x32_fp8_fp8` instruction.
```bash
./matrix_calculator.py --architecture gfx942 --instruction v_mfma_f32_16x16x32_fp8_fp8 --register-layout --C-matrix
```
<img width="1113" height="537" alt="image"
src="https://github.com/user-attachments/assets/afc8f556-08cc-4224-a6e5-b5edabc5fc02"
/>
The above shows that threads are responsible for consecutive elements
down a column of the C tile. If we use this distribution to read and
write to partials with C in row major, then threads are unable to
perform vectorized reads and writes. Note: thread 0 is shown in red and
thread 1 is shown in green.
Since the C-shuffle Epilogue only supports C in row major, reading and
writing to partials is highly unoptimized.
### Problem 2: Missed opportunity for SPGR use in tree reduction loop
Since the reduction occurs between workgroups, all threads in the
workgroup follow the same execution paths in the tree reduction logic,
hence various variables should be using SGPRs, but they are not.
### Implemented Solutions
1. Add a new tile distribution encoding that is optimized for accessing
partials in HBM. This encoding does not change the data assignment to
threads, it merely changes the addresses to which they write/read in the
partials buffer. For example, continuing with the
`v_mfma_f32_16x16x32_fp8_fp8` instruction, the new encoding would result
in threads writing in the following layout:
<img width="517" height="342" alt="image"
src="https://github.com/user-attachments/assets/93b5e0ea-bafc-47b8-89bb-c40ba75cb202"
/>
This layout ensures that each thread writes along a row, enabling
`buffer_{store|load}_dwordx4` instructions (i.e., vectorized accesses).
This helps reduce register usage due to requiring fewer offset
calculations.
2. To force SGPR usage in the tree reduction loop, I make use of CK
Tile's `amd_wave_read_first_lane` which is a wrapper around
`__builtin_amdgcn_readfirstlane`. This helps reduce VGPR spills in the
tree reduction.
_These changes do not fully eliminate register spills. Future work will
aim to further reduce spills. But these changes make good progress._
## Test Plan
Added tests for different warp tile sizes to validate that the new
encoding works with different `WarpGemm` variants.
## Test Result
All tests pass locally on all gfx9 architectures.
Some results for decreases in register spills on gfx942: (BL = baseline)
| Kernel | SGPR Spill (BL) | SGPR Spill (new) | SGPR Delta | SGPR % |
VGPR Spill (BL) | VGPR Spill (new) | VGPR Delta | VGPR % |
|--------|------------------:|------------------:|-----------:|-------:|-------------------:|------------------:|-----------:|-------:|
| fp16 linear F/F/F/T 256x256x32 2x2x1 32x32x16 | 223 | 0 | -223 |
-100.0% | 21 | 20 | -1 | -4.8% |
| fp16 tree F/F/F/T 256x256x32 2x2x1 32x32x16 | 233 | 11 | -222 | -95.3%
| 443 | 23 | -420 | -94.8% |
| fp8 linear F/F/F/F 256x256x32 2x2x1 32x32x32 | 221 | 3 | -218 | -98.6%
| 12 | 6 | -6 | -50.0% |
| fp8 tree F/F/F/F 256x256x32 2x2x1 32x32x32 | 230 | 14 | -216 | -93.9%
| 396 | 12 | -384 | -97.0% |
## Submission Checklist
- [x] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
[CK_TILE] Update Stream-K Reduction Strategy Enum
## Motivation
Currently, Stream-K has 3 reduction options: 1) atomics, 2) The
reduction described in the Stream-K paper, and 3) a tree reduction. The
reduction strategy described in the original Stream-K paper has the
starting workgroup of each tile sequentially accumulating partial
results of other contributing workgroups in the tile, which requires a
linear number of steps. Hence, for clarity, this works updates the
naming of the `StreamKReductionStrategy` enum members to better describe
the existing reduction strategy options.
## Technical Details
Prior to this change, the enum is as follows:
```cpp
enum StreamKReductionStrategy : uint32_t
{
Atomic = 0u,
Reduction = 1u,
TreeReduction = 2u
};
```
But, the distinction between `Reduction` and `TreeReduction` is not very
clear and has some redundancy.
Hence, the updated enum is as follows:
```cpp
enum StreamKReductionStrategy : uint32_t
{
Atomic = 0u,
Linear = 1u,
Tree = 2u
};
```
All references to `StreamKReductionStrategy` were updated to reflect
this change.
## Test Plan
No new functionality was added, so no new tests were added; I just
validated existing tests and examples.
## Test Result
All tests passed locally.
## Submission Checklist
- [x] Look over the contributing guidelines at
https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.
* Fix alignment issue in Stream-K workspace buffer
In CK Tile Stream-K, the workspace buffer is used to hold flags and
partials, where the first i bytes holds the flags and the remaining
bytes hold partials. This change adds padding to the flags prefix of the
workspace buffer to ensure the number of bytes is 128B-aligned. Without
this alignment, since workgroups do not skip cache when reading from
partials, they may read stale partials data in cache, leading to
incorrect results. The added padding avoids the stale data reading.
This change also re-enables the test_ck_tile_streamk_reduction tests.
* Compute reference GEMM on GPU for test verification to decrease testing time
* initial poc
* factor out common parts in operator()
* cv4
* rest of the universal gemm pipelines
* fix test
* remove boilerplate from tile engine
* fix example
* fix example
* format
* fix tests build for gemm
* remove base pipeline codegen from gemm instance builder
* unify v3 logic with the rest of universal gemm pipelines
* fix build for multi abd test
* fix test gemm multi d
* fix build for weight preshuffle
* fix grouped gemm test
* fix grouped gemm multi d test
* fix grouped gemm preshuffle
* fix grouped gemm example except for quant
* fix gemm preshuffle
* fix splitk 2 stage example
* fix batched gemm example
* fix multid example
* fix multiabd example
* fix batched gemm test
* fixup
* fix examples build
* fix grouped gemm test build
* fix smoke builder
* hacky poc
* fix tile engine
* kill the lambda
* maybe fix test build
* more fixes
* clang-format
* save temp
* clang-format
* mostly fix examples
* clang-format
* remove dead code
* more cleanup
* fix fmha bwd build (default epilogue set/add appears to be broken)
* fix default epilogue tests but not correctness
* clang-format
* fix bquant
* clang-format
* cleanup dead code
* rearrange make windows for readability
* restore changes to IsSupportedArgument
* fix smoke-builder
* clang-format
* fixup rename class
* build fixes
* clang-format
* fix builder
* fixup
* remove set from builder tests
* fix test
* clang-format
* re-refactor the kernels
* clang-format
* fix header license
* remove memory operation from conv bwd test
* clang-format
* clang-format example,include
* clang-format test
* build fixes
* clang-format
* solve compilation error
* fix the CI
* solve compilation error
* clang format
* solve merge conflict
* solve merge conflict
* solve the gfx11 error
* solve test error
* moar build fixes
* remove AtomicAddRequiresKBatchGreaterThanOne test since the property is removed from the kernel scope
---------
Co-authored-by: Thomas Ning <Thomas.Ning@amd.com>
* CK Tile Stream-K Tree Reduction
This change adds the first implementation of the Stream-K tree reduction
strategy into CK Tile. The tree reduction reduces the the number of
steps for accumulating results for a tile from O(N) to O(logN) where N
is the number of workgroups contributing to a C tile.
Additionally, in the original non-atomic reduction strategy, atomics
were used to set the flags buffer and to read from the flags buffer.
Howeover, through investigation with the tree reduciton, atomics with
default (relaxed) semantics were not enough to guarantee workgroups
would not read stale data, leading to incorrect results. Stronger
acquire/release memory orderings are too expensive. So, this change
also eliminates the use of atomics for setting the flags. Instead, we
leverage cache modifiers (e.g., GLC) to avoid writing to cache, thereby
avoiding the use of atomics.
Prelimiary tests were also added for the normal reduction and tree
reduction. More will be added in a future PR via tile engine.
* Move Stream-K kernel files to a subdirectory
* Cleanup Code Style & Handle Unsupported Reductions
This change makes the following small changes:
- Add an explicit else block for unimplemented reduction strategies
- Clarify type of sk_flags_ptr via auto*
- Add description for extra_iters_before_me variable
* Run new copyright script on new files
