Landing: 0d5fe4ed0540
Project / Subsystem
gcc / gcc/ivopts
Date
2026-08-29
Author
Jovan Dmitrovic
Commit
0d5fe4ed0540cca156754a905387c3420465b210
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc/ivopts
- patch_id
- —
- commit_hash
- 0d5fe4ed0540cca156754a905387c3420465b210
- source_type
- github
- headline
- ivopts: Refine register pressure estimate for loop invariants
- tldr
- Register pressure estimation in loop invariant optimization is adjusted for more accurate spilling costs.
- author
- Jovan Dmitrovic
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- gcc:ivopts: adjust reg pressure estimate for spilling invariants compared to iv cands
- series_parts
- []
- tags
-
- • optimization
- • gcc
- • loops
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-08-29T00:00:00.000Z
The ivopts pass has adjusted its register pressure estimation to more accurately reflect the cost of spilling loop invariants versus induction variables. Previously, it assumed spilling loop invariants was half the cost of spilling induction variables. This change corrects the calculation to account for the fact that invariants only need to be loaded once, while induction variables must be loaded and stored per loop iteration.