Re: [PATCH] x86: Support BHI_CTRL instruction
Project / Subsystem
binutils / x86
Date
2026-08-05
Proposer
Jan Beulich
Source type
public_inbox
Consensus
Proposed
Sentiment
5/10
All attributes
- project
- binutils
- subsystem
- x86
- patch_id
- —
- discussion_id
- 20260601062446.2367458-1-haochen.jiang@intel.com
- source_type
- public_inbox
- title
- Re: [PATCH] x86: Support BHI_CTRL instruction
- headline
- x86: Support BHI_CTRL instruction
- tldr
- Discussion continues on the x86 BHI_CTRL instruction support, specifically regarding the correct handling of REX.W and REX2.W prefixes.
- proposer
- Jan Beulich
- consensus
- Proposed
- outcome
- under_review
- sentiment_score
- 5
- technical_tradeoffs
- []
- series_id
- 20260601062446.2367458-1-haochen.jiang@intel.com
- series_role
- reply
- series_parts
- []
- tags
-
- • x86
- • disassembler
- • instruction-encoding
- bugzilla_url
- —
- date
- 2026-08-05T00:00:00.000Z
Re: [PATCH] x86: Support BHI_CTRL instruction
This discussion revolves around the correct implementation of the BHI_CTRL instruction for x86 in binutils, particularly concerning the encoding and usage of REX prefixes. The initial patch proposed using Size64 to ensure REX.W is emitted. A key point of debate is whether REX2.W should have the same effect as REX.W for this instruction, as the documentation is unclear. There’s a call for a test case to clarify this behavior and ensure the disassembler handles potential ambiguities correctly.