Landing: 372d44c5611e
Project / Subsystem
gcc / gcc/match
Date
2026-08-04
Author
Avinal Kumar
Commit
372d44c5611ecce9144c985a849ca06f108289fe
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc/match
- patch_id
- —
- commit_hash
- 372d44c5611ecce9144c985a849ca06f108289fe
- source_type
- github
- headline
- Simplify bitwise comparisons involving powers of two
- tldr
- Optimizes bitwise OR comparisons to AND for powers of two, potentially improving performance.
- author
- Avinal Kumar
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • optimization
- • bitwise
- • compiler
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-08-04T00:00:00.000Z
This change simplifies expressions of the form (A | C) == A to (A & C) != 0 when C is a power of two. This optimization avoids a bitwise OR and replaces it with a bitwise AND and a comparison against zero, which can be more efficient on some architectures. The inverse transformation for (A | C) != A to (A & C) == 0 is also included. A new test case verifies the optimization.