Landing: 9056e455be6a
Project / Subsystem
gcc / avr
Date
2026-08-15
Author
Georg-Johann Lay
Commit
9056e455be6aae7936899ae03cf5b07beff0162b
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- avr
- patch_id
- —
- commit_hash
- 9056e455be6aae7936899ae03cf5b07beff0162b
- source_type
- github
- headline
- AVR: Optimize register comparisons with constants divisible by 256
- tldr
- Reduces AVR compare instruction count when comparing registers to constants.
- author
- Georg-Johann Lay
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • avr
- • optimization
- • code size
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-08-15T00:00:00.000Z
This patch optimizes comparisons of AVR registers against constants. When the constant is a multiple of 256, the compiler now uses a more efficient instruction sequence for equality (EQ) and inequality (NE) checks. This change reduces the generated code size by one instruction in such cases, improving performance and code density for specific AVR targets.