Landing: b1dcde565577
Project / Subsystem
gcc / phiopt
Date
2026-09-16
Author
Andrea Pinski
Commit
b1dcde565577e8ae1b6297e4a230f040e6aa6547
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- phiopt
- patch_id
- —
- commit_hash
- b1dcde565577e8ae1b6297e4a230f040e6aa6547
- source_type
- github
- headline
- phiopt: Improve heuristics for factoring out loads before vectorization
- tldr
- PHIOPT pass in GCC improves load commoning heuristics to enable more loop vectorization opportunities.
- author
- Andrea Pinski
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • optimization
- • vectorization
- • phiopt
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-09-16T00:00:00.000Z
The PHIOPT pass in GCC now uses improved heuristics for commoning loads before the vectorizer runs. Previously, many common loads were rejected due to simple heuristics. This change allows loads from other loads to be factored out earlier, potentially enabling more code to be vectorized. Two test cases are now factored out in phiopt2, and one case was adjusted to preserve vectorization.