Landing: 10f6e51b8250
Project / Subsystem
gcc / gcc/simplify-rtx
Date
2026-07-20
Author
Richard Biener
Commit
10f6e51b8250ce4f553c055ad737607332311a5d
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- gcc/simplify-rtx
- patch_id
- —
- commit_hash
- 10f6e51b8250ce4f553c055ad737607332311a5d
- source_type
- github
- headline
- Simplify scalar vec_select of vec_concat patterns
- tldr
- GCC's RTX simplification pass now handles scalar `vec_select` operations applied to `vec_concat`, enabling further optimization opportunities.
- author
- Richard Biener
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • gcc
- • optimization
- • x86
- • vector
- • simplify
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-07-20T00:00:00.000Z
This commit enhances GCC’s simplify-rtx pass by introducing simplification for scalar vec_select operations that wrap vec_concat. Previously, such patterns might not have been simplified effectively, hindering subsequent optimizations. The new simplification allows these complex vector concatenations and selections to be resolved into simpler forms that the backend, particularly x86, can better recognize and optimize, potentially leading to improved performance.