Landing: bbf9808d787e
Project / Subsystem
gcc / gcc
Date
2026-09-23
Author
Richard Biener
Commit
bbf9808d787eacf4464f2298d2f4265855b006bf
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc
- patch_id
- —
- commit_hash
- bbf9808d787eacf4464f2298d2f4265855b006bf
- source_type
- github
- headline
- Account for SSE to integer move cost for vec_to_scalar
- tldr
- GCC now accounts for the cost of moving data from SSE registers to general-purpose registers.
- author
- Richard Biener
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • optimization
- • x86
- • performance
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-09-23T00:00:00.000Z
GCC’s cost model for vector operations has been updated to include the extra cost of converting a vector’s element to an integer scalar. This change specifically addresses the vec_to_scalar operation when the target is a general-purpose register, ensuring more accurate performance estimations by accounting for the lane extraction process.