Landing: 54f8428e0342
Project / Subsystem
gcc / gcc
Date
2026-05-16
Author
Jakub Jelinek
Commit
54f8428e0342935d5f9c3282fbae1db63cf90ac1
Source
github
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc
- patch_id
- —
- commit_hash
- 54f8428e0342935d5f9c3282fbae1db63cf90ac1
- source_type
- github
- headline
- Add __builtin_bitreverse128 intrinsic.
- tldr
- Introduces the `__builtin_bitreverse128` intrinsic for reversing the bit order of 128-bit integers.
- author
- Jakub Jelinek
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • builtin
- • bitreverse
- • optimization
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-05-16T00:00:00.000Z
This commit adds a new builtin function, __builtin_bitreverse128, to GCC. This function reverses the order of bits within a 128-bit integer. Having this builtin allows the compiler to generate optimized code for bit reversal on 128-bit values, which is useful in some specialized algorithms.