Landing: b0fcf6cab6b4
Project / Subsystem
gcc / gcc/tree-optimization
Date
2026-09-17
Author
Richard Biener
Commit
b0fcf6cab6b44d916992f17297d7c248d64469dc
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc/tree-optimization
- patch_id
- —
- commit_hash
- b0fcf6cab6b44d916992f17297d7c248d64469dc
- source_type
- github
- headline
- Fix vectorizer dependence analysis for negative step stores
- tldr
- Vectorizer now correctly analyzes store dependencies with negative steps to preserve scalar order.
- author
- Richard Biener
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • gcc
- • vectorization
- • optimization
- • dependence-analysis
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-09-17T00:00:00.000Z
A missed check in GCC’s vectorizer’s dependence analysis has been corrected. The analysis now properly considers the preservation of scalar order for stores that have a negative step distance. This ensures that the compiler generates correct code in cases where stores access memory locations in reverse order, preventing potential data corruption.