Landing: cea04b88c16b
Project / Subsystem
gcc / tree-ssa-threadbackward
Date
2026-09-10
Author
Aldy Hernandez
Commit
cea04b88c16b25f0119062cc65db9ab778c4e24b
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- tree-ssa-threadbackward
- patch_id
- —
- commit_hash
- cea04b88c16b25f0119062cc65db9ab778c4e24b
- source_type
- github
- headline
- backthreader: compute path profitability incrementally
- tldr
- backthreader computes path profitability incrementally, improving performance by 7.8%.
- author
- Aldy Hernandez
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • optimization
- • performance
- • backthreader
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-09-10T00:00:00.000Z
The backthreader pass now computes path profitability incrementally, avoiding expensive recomputation at each node. This change speeds up the threader by 7.8% while ensuring identical assembly output and identical path/stats compared to the previous version. The implementation was refined to use new push_bb and pop_bb functions and an accumulated stats mechanism.