Landing: f6ee4d2a6070
Project / Subsystem
gcc / aarch64
Date
2026-09-23
Author
Tamar Christina
Commit
f6ee4d2a6070fda98a7cbb65aa8b3bb2903d77d0
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- aarch64
- patch_id
- —
- commit_hash
- f6ee4d2a6070fda98a7cbb65aa8b3bb2903d77d0
- source_type
- github
- headline
- Consistently apply Vector Length (VF) cap in AArch64 cost model.
- tldr
- AArch64 cost model now uniformly applies vector length caps for better loop optimization accuracy.
- author
- Tamar Christina
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • aarch64
- • optimization
- • cost model
- • vectorization
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-09-23T00:00:00.000Z
The AArch64 backend ensures that the Vector Length (VF) cap is applied consistently across both the statement body cost adjustment and the main loop comparison logic. This resolves discrepancies where the compiler might have ranked the same loop differently due to uncapped VF in one part of the cost model and capped in another, leading to more accurate optimization decisions for fixed-trip loops.