Landing: 9e3e6ceb3b18
Project / Subsystem
gcc / gcc
Date
2026-04-02
Author
Gopi Kumar Bulusu
Commit
9e3e6ceb3b18c0dd57f49ef7eb28c9462575a282
Source
github
Impact
5/10
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc
- patch_id
- —
- commit_hash
- 9e3e6ceb3b18c0dd57f49ef7eb28c9462575a282
- source_type
- github
- headline
- Fix incorrect length for __builtin_bswap16.
- tldr
- Corrects the instruction length attribute for `__builtin_bswap16` on Microblaze to prevent scheduling errors.
- why_it_matters
- Addresses a scheduling issue on Microblaze, preventing potential crashes due to incorrect instruction placement in delay slots.
- author
- Gopi Kumar Bulusu
- impact_score
- 5
- impact_rationale
- Fixes a scheduling issue related to `__builtin_bswap16` on Microblaze, preventing potential runtime issues.
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • microblaze
- • bswap16
- • scheduling
- • optimization
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-04-02T00:00:00.000Z
The bswaphi pattern, corresponding to __builtin_bswap16, was missing the length attribute, causing the compiler to assume a default length of 8 bytes. On Microblaze, this could lead to the 8-byte bswaphi instruction being incorrectly scheduled into a branch instruction’s delay slot, which only accommodates 4-byte instructions. This patch corrects the length attribute, preventing this scheduling error.