[executorch][cuda] Optimize short-query INT6 matvec kernels - #21504
Merged
Conversation
Pull Request resolved: #21473 Add compile-time M=2/3/4 fused short-query kernels while preserving the existing M=1 path. The shared ROWS template was reviewed and benchmarked by KernelAgent; KA found no faster safe rewrite, so the validated template is retained. A100 kernel microbenchmarks versus main: - M1: 0.10226 -> 0.10228 ms (performance neutral; no regression) - M2: 0.196 -> 0.127 ms (1.54x) - M3: 0.289 -> 0.159 ms (1.82x) - M4: 0.383 -> 0.196 ms (1.95x) Correctness tests cover M=1,2,3,4 with three randomized seeds. ptxas reports zero spills. ghstack-source-id: 408535989 @exported-using-ghexport Differential Revision: [D114032326](https://our.internmc.facebook.com/intern/diff/D114032326/)
Pull Request resolved: #21474 Add compile-time M=1/2/3/4 short-query paths and share their safe implementation through a ROWS/USE_SUM/GS16 device template. These kernels were generated and tuned with KernelAgent. Dispatch uses the regular gs16 kernels for M=1/2 and the precomputed-activation-sum kernels for M=3/4. The M=3 non-sum entry remains explicit as a performance/correctness comparison because templating that entry increased register pressure. A100 op-level results (N=6656, gs=16, three seeds): - M1, generic reference -> gs16: 0.039416 -> 0.038211 ms (1.032x; no regression) - M2, generic reference -> gs16: 0.055348 -> 0.032540 ms (1.701x) - M3, optimized non-sum -> activation-sum: 0.040003 -> 0.039949 ms (1.001x; neutral incremental change) - M4, generic reference -> activation-sum: 0.100204 -> 0.045694 ms (2.193x) The M3 baseline is intentionally the optimized non-sum kernel rather than the generic reference; this isolates the activation-sum optimization. All candidates are bitwise-correct across the three seeds, and ptxas reports zero spills. ghstack-source-id: 408539235 @exported-using-ghexport Differential Revision: [D114032330](https://our.internmc.facebook.com/intern/diff/D114032330/)
🔗 Helpful Links🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/executorch/21504
Note: Links to docs will display an error until the docs builds have been completed. This comment was automatically generated by Dr. CI and updates every 15 minutes. |
meta-cla
Bot
added
the
CLA Signed
This PR needs a
|
Gasoonjia
approved these changes
Jul 30, 2026
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This PR was created by the merge bot to help merge the original PR into the main branch.
ghstack PR number: #21474 by @Gasoonjia
^ Please use this as the source of truth for the PR details, comments, and reviews
ghstack PR base: https://github.com/pytorch/executorch/tree/gh/gasoonjia/179/base
ghstack PR head: https://github.com/pytorch/executorch/tree/gh/gasoonjia/179/head
Merge bot PR base: https://github.com/pytorch/executorch/tree/gh/gasoonjia/178/orig
Merge bot PR head: https://github.com/pytorch/executorch/tree/gh/gasoonjia/179/orig
Differential Revision: D114032330
@diff-train-skip-merge