Landing: 6c8c0809015a
Project / Subsystem
gcc / i386
Date
2026-04-26
Author
Roger Sayle
Commit
6c8c0809015a3f2e663d3e1a3e0d2fe2117fb6a7
Source
github
Perf win
No
Breaking
No
All attributes
- project
- gcc
- subsystem
- i386
- patch_id
- —
- commit_hash
- 6c8c0809015a3f2e663d3e1a3e0d2fe2117fb6a7
- source_type
- github
- headline
- i386: Refactor AVX512 comparisons in machine description sse.md.
- tldr
- GCC's x86 backend now has a cleaner organization of AVX512 vector comparisons, avoiding nonsensical instruction combinations.
- author
- Roger Sayle
- outcome
- committed
- performance_win
- false
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • i386
- • x86
- • avx512
- • vectorization
- • code generation
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-04-26T00:00:00.000Z
The x86 backend in GCC has been refactored to improve the organization of AVX512 vector comparisons. The previous organization led to the generation of potentially invalid instructions (e.g., integer comparisons specifying floating-point rounding modes). The new structure uses a more logical decomposition of patterns, ensuring that only valid instruction combinations are generated. This improves code quality by using the correct instructions.