Landing: c348f5c5e991
Project / Subsystem
gcc / gcc/risc-v
Date
2026-07-18
Author
Dusan Stojkovic
Commit
c348f5c5e991dd9d4e13d5943485a938cc4342a8
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc/risc-v
- patch_id
- —
- commit_hash
- c348f5c5e991dd9d4e13d5943485a938cc4342a8
- source_type
- github
- headline
- Optimize bit manipulation for RISC-V, reducing instruction count.
- tldr
- Improved RISC-V code generation for bit manipulation sequences, reducing instruction count.
- author
- Dusan Stojkovic
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • risc-v
- • optimization
- • performance
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-07-18T00:00:00.000Z
This commit introduces a new pattern in the RISC-V backend’s match.pd to optimize specific bit manipulation sequences. It targets constructs like (1 << N) & (1 << N) where shifts occur in different types. By collapsing these into a single bit set operation within the wider type, the code generation is significantly improved, reducing an instruction sequence from six to three on rv64gcb.