Landing: a22b31304e0a
Project / Subsystem
gcc / gcc/vectorization
Date
2026-04-24
Author
Richard Biener
Commit
a22b31304e0a1ad21751f882c02c32c167c78793
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc/vectorization
- patch_id
- —
- commit_hash
- a22b31304e0a1ad21751f882c02c32c167c78793
- source_type
- github
- headline
- Enable compare costs by default for x86 vectorization.
- tldr
- GCC now enables vector cost comparison by default for x86, improving vectorization decisions.
- author
- Richard Biener
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • gcc
- • vectorization
- • x86
- • optimization
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-04-24T00:00:00.000Z
The default behavior of the ix86-vect-compare-costs parameter has been flipped, enabling vector cost comparison by default for x86. This change, driven by discussions during stage3/4, aims to improve vectorization decisions by comparing the costs of different vectorization strategies. Several test cases were updated and adjusted to reflect the new default, ensuring that existing functionality remains intact while leveraging the benefits of cost comparison.