Landing: 0947d9741362
Project / Subsystem
gcc / i386
Date
2026-09-21
Author
Uros Bizjak
Commit
0947d974136292205743bc9bdaca5eb1ea0d6d67
Source
github
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- i386
- patch_id
- —
- commit_hash
- 0947d974136292205743bc9bdaca5eb1ea0d6d67
- source_type
- github
- headline
- Fix enabled attribute for V2QI negate/plusminus insns
- tldr
- Corrects the 'enabled' attribute for MMX V2QI negate and plusminus instructions on i386.
- author
- Uros Bizjak
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • i386
- • mmx
- • optimization
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-09-21T00:00:00.000Z
The ‘enabled’ attribute for certain MMX instructions on the i386 architecture, specifically negv2qi2 and v2qi3 (plusminus), was incorrectly using a condition that could change during optimization (optimize_function_for_size_p). This commit modifies the attribute to use optimize_size instead, ensuring it remains a stable, pass-invariant property as required by RTL documentation, thereby fixing a bug related to optimization stability.