Landing: 7d84a357cfaa
Project / Subsystem
gcc / x86_cse
Date
2026-05-08
Author
H.J. Lu
Commit
7d84a357cfaa3d9ff2cc600a3c145780d37b6aed
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- x86_cse
- patch_id
- —
- commit_hash
- 7d84a357cfaa3d9ff2cc600a3c145780d37b6aed
- source_type
- github
- headline
- x86_cse: Check CONST0_RTX and CONSTM1_RTX During Vectorization
- tldr
- The x86 CSE pass now correctly handles CONST0_RTX and CONSTM1_RTX for constant vectors during vectorization, improving code generation.
- author
- H.J. Lu
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • x86
- • cse
- • vectorization
- • optimization
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-05-08T00:00:00.000Z
This commit fixes an issue in the x86 common subexpression elimination (CSE) pass where CONST0_RTX and CONSTM1_RTX were not correctly handled for constant vectors. The fix ensures that during vectorization, redundant vector loads are properly replaced when the source is a constant vector of zeros or minus ones. This leads to better code generation by avoiding unnecessary computations.