Avoid copy of flipped A matrices in GEMV #1389
Merged
Conversation
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
ricardoV94
force-pushed
the
gemv_negative_strides
branch
2 times, most recently
from
13c5678 to
bff7188
Compare
There was a problem hiding this comment.
Pull Request Overview
This PR improves the GEMV implementation to avoid making a copy of the A matrix when it is flipped, with additional benchmarking tests to measure the performance benefit. Key changes include new C-code paths in gemv_c_code to handle negative strides, updates to the CGemv cache version, and the addition of performance tests in tests/tensor/test_blas_c.py.
Reviewed Changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.
| File | Description |
|---|---|
| tests/tensor/test_blas_c.py | Added a new benchmark test for GEMV with negative strides |
| pytensor/tensor/blas_c.py | Refactored GEMV C code to avoid unnecessary copies and handle reversed strides |
ricardoV94
force-pushed
the
gemv_negative_strides
branch
from
bff7188 to
09069cd
Compare
Codecov ReportAll modified and coverable lines are covered by tests ✅
Additional details and impacted files@@ Coverage Diff @@
## main #1389 +/- ##
=======================================
Coverage 82.02% 82.02%
=======================================
Files 207 207
Lines 49294 49294
Branches 8746 8746
=======================================
Hits 40433 40433
Misses 6695 6695
Partials 2166 2166
🚀 New features to boost your workflow:
|
jessegrabowski
approved these changes
May 6, 2025
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
Related #1388
Benchmark results for the new test
Before
After
There are still other things we probably want to do, regarding the copy / allocation layout of y when not inplace, but that I won't touch now.
We can do a similar trick for the GER implementation, and perhaps other blas Ops
📚 Documentation preview 📚: https://pytensor--1389.org.readthedocs.build/en/1389/