Landing: 12e4a2acda8d
Project / Subsystem
gcc / x86_cse
Date
2026-04-30
Author
H.J. Lu
Commit
12e4a2acda8da558010c9962f96b3167aee21072
Source
github
Perf win
Yes
Breaking
No
All attributes
- project
- gcc
- subsystem
- x86_cse
- patch_id
- —
- commit_hash
- 12e4a2acda8da558010c9962f96b3167aee21072
- source_type
- github
- headline
- x86_cse: Add X86_CSE_CONST_VECTOR for native CONST_VECTOR.
- tldr
- GCC's x86 common subexpression elimination (CSE) now handles CONST_VECTOR and constant integer loads more efficiently.
- author
- H.J. Lu
- outcome
- committed
- performance_win
- true
- breaking_change
- false
- series_id
- —
- series_parts
- []
- tags
-
- • x86
- • optimization
- • cse
- • vectorization
- discussion_id_link
- —
- bugzilla_pr
- —
- date
- 2026-04-30T00:00:00.000Z
This commit enhances GCC’s x86 common subexpression elimination (CSE) pass to better handle CONST_VECTORs. It introduces X86_CSE_CONST_VECTOR for native CONST_VECTORs, avoids dataflow (DF) chains by using CONST_VECTOR in REG_EQUAL notes, and preserves constant integer loads across function calls when beneficial. Additionally, it converts CONST_VECTOR loads (no larger than an integer register) to constant integer loads.