Landing: 365e5618bc6f
Project / Subsystem
gcc / gcc/match
Date
2026-05-24
Author
Raven Hallsby
Commit
365e5618bc6fcb62560450677e0fe4f5ba96345e
Source
github
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc/match
- patch_id
- —
- commit_hash
- 365e5618bc6fcb62560450677e0fe4f5ba96345e
- source_type
- github
- headline
- Optimize `(~y & x) ^ y` into `(y | x)`
- tldr
- GCC now optimizes the expression `(~y & x) ^ y` into `(y | x)` to simplify code.
- author
- Raven Hallsby
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • optimization
- • pattern matching
- • code simplification
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-05-24T00:00:00.000Z
GCC’s pattern matching now transforms the expression (~y & x) ^ y into its simpler equivalent (y | x). This optimization was needed because the front-end performs constant optimizations like ~1 -> -2 before the existing similar rule could be applied.