Landing: 15cabcf0bd5d
Project / Subsystem
gcc / i386
Date
2026-09-10
Author
Roger Sayle
Commit
15cabcf0bd5d964181d43fb6b8c7daeebf874e24
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- i386
- patch_id
- —
- commit_hash
- 15cabcf0bd5d964181d43fb6b8c7daeebf874e24
- source_type
- github
- headline
- i386: Use insertps for SSE vector permutations
- tldr
- Improves SSE vector permutation performance on x86 by using the insertps instruction.
- author
- Roger Sayle
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • i386
- • SSE
- • optimization
- • vectorization
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-09-10T00:00:00.000Z
This patch enhances the i386 backend’s ability to implement vector permutations for V4SI and V4SF types by leveraging the SSE 4.1 insertps instruction. Previously, such operations resulted in multiple instructions; now, they can be consolidated into a single insertps instruction, significantly reducing code size and improving performance. This also aids in optimizing zero-extension operations for SSE registers.