Landing: fff26a966b9f
Project / Subsystem
gcc / gcc
Date
2026-05-01
Author
Jeff Law
Commit
fff26a966b9f686bbdfb1baaac757bd9352af7fd
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc
- patch_id
- —
- commit_hash
- fff26a966b9f686bbdfb1baaac757bd9352af7fd
- source_type
- github
- headline
- Improve RISC-V code generation for xor+xor+ior sequences
- tldr
- Improves RISC-V code generation by transforming `xor+xor+ior` sequences into more efficient `andn+xor` instructions.
- author
- Jeff Law
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • risc-v
- • optimization
- • code generation
- • bit manipulation
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-05-01T00:00:00.000Z
This commit optimizes the code sequence generated for expressions like (a ^ b) ^ (a | c) on RISC-V. Instead of generating xor, or, xor instructions, the compiler now generates andn, xor when possible, which is more efficient. This optimization can lead to performance improvements for code that uses this type of expression.