Landing: bc9bd4e9dcd3
Project / Subsystem
gcc / aarch64
Date
2026-04-27
Author
Soumya AR
Commit
bc9bd4e9dcd3f4bc5617606b1a370b2c9b2b825e
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- aarch64
- patch_id
- —
- commit_hash
- bc9bd4e9dcd3f4bc5617606b1a370b2c9b2b825e
- source_type
- github
- headline
- Update br_mispredict_factor for generic tunings
- tldr
- The `br_mispredict_factor` for generic AArch64 tunings is updated from 6 to 7, improving performance on SPEC2017 fp rate.
- author
- Soumya AR
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • aarch64
- • optimization
- • performance
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-04-27T00:00:00.000Z
This commit updates the br_mispredict_factor from 6 to 7 for generic AArch64 tunings. Testing revealed that a value of 7 is more suitable, preventing the compiler from rejecting cheaper conditional selects (csels) in favor of conditional branches in some workloads. On an Olympus core, this change improves SPEC2017 floating-point rate geomean by 1% with no significant regressions.