Landing: a7bdb519ace4
Project / Subsystem
gcc / aarch64
Date
2026-08-11
Author
Kyrylo Tkachov
Commit
a7bdb519ace49050d2c59c78829edfb216afef64
Source
github
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- aarch64
- patch_id
- —
- commit_hash
- a7bdb519ace49050d2c59c78829edfb216afef64
- source_type
- github
- headline
- Define __ARM_FEATURE_CSSC ACLE macro
- tldr
- GCC now defines the __ARM_FEATURE_CSSC macro for the Arm Common Short Sequence Compression instructions.
- author
- Kyrylo Tkachov
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • aarch64
- • compiler builtins
- • feature macros
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-08-11T00:00:00.000Z
GCC now defines the __ARM_FEATURE_CSSC macro, as specified by ACLE 2025 Q3. This macro is set to 1 when the Common Short Sequence Compression (FEAT_CSSC) instructions are available on the aarch64 architecture. Although GCC has generated code for these instructions since version 13, it previously did not define this feature test macro, unlike Clang. This change ensures feature compatibility and correct preprocessor behavior for code targeting these instructions.