[PATCH 1/3] x86: slightly simplify VPBROADCASTQ -> VUNPCKLQDQ optimization again
Project / Subsystem
binutils / x86
Date
2026-07-17
Proposer
Jan Beulich <jbeulich@suse.com>
Source type
public_inbox
Consensus
Proposed
Sentiment
—/10
Technical tradeoffs
- • Corrects a functional bug in instruction optimization.
- • Improves the accuracy of instruction selection for AVX instructions.
All attributes
- project
- binutils
- subsystem
- x86
- patch_id
- —
- discussion_id
- ac3b0417-f5b7-4297-9cfa-46e1b951c324@suse.com
- source_type
- public_inbox
- title
- [PATCH 1/3] x86: slightly simplify VPBROADCASTQ -> VUNPCKLQDQ optimization again
- headline
- x86: Simplify VPBROADCASTQ -> VUNPCKLQDQ optimization.
- tldr
- Fixes an overzealous check in the x86 assembler's VPBROADCASTQ optimization.
- proposer
- Jan Beulich <jbeulich@suse.com>
- consensus
- Proposed
- outcome
- proposed
- sentiment_score
- —
- technical_tradeoffs
-
- • Corrects a functional bug in instruction optimization.
- • Improves the accuracy of instruction selection for AVX instructions.
- series_id
- binutils:x86: slightly simplify vpbroadcastq -> vunpcklqdq optimization again
- series_role
- reply
- series_parts
- []
- tags
-
- • x86
- • assembler
- • AVX
- • optimization
- • instruction selection
- bugzilla_url
- —
- date
- 2026-07-17T00:00:00.000Z
[PATCH 1/3] x86: slightly simplify VPBROADCASTQ -> VUNPCKLQDQ optimization again
This patch corrects an optimization in the x86 assembler related to the VPBROADCASTQ instruction. It removes an unnecessary check for the xmmword property on the source operand, which was overly strict and incorrectly disabled valid transformations. The fix ensures that the optimization correctly identifies when VPBROADCASTQ can be transformed into VUNPCKLQDQ.