Landing: f74150ec2828
Project / Subsystem
gcc / RISC-V
Date
2026-08-19
Author
Jojo R
Commit
f74150ec28282824b0a9bd298b87210e880ddec3
Source
github
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- RISC-V
- patch_id
- —
- commit_hash
- f74150ec28282824b0a9bd298b87210e880ddec3
- source_type
- github
- headline
- Reject table-based CRC optabs for size optimization.
- tldr
- RISC-V CRC optimization now avoids large lookup tables when optimizing for code size.
- author
- Jojo R
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • RISC-V
- • optimization
- • code size
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-08-19T00:00:00.000Z
RISC-V CRC optimization logic has been updated to prevent the use of a large, 256-entry lookup table when optimizing for code size (-Os, -Oz). This table-based fallback significantly increases code size, especially when CLMUL expansion is unavailable. The compiler now checks TARGET_OPTAB_SUPPORTED_P for crc_rev_optab, allowing the table fallback only for speed optimizations, and for size optimizations only when hardware CLMUL extensions (Zbc, Zbkc, Zvbc) are available and the result mode is small.