Landing: 5a81fdb8059c

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Project / Subsystem

binutils / binutils/x86

Date

2026-10-05

Author

Jan Beulich <jbeulich@sourceware.org>

Commit

5a81fdb8059c79fbf8d6b2ab1c765c930ac734ad

Source

public_inbox

Perf win

Breaking

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All attributes

project: binutils
subsystem: binutils/x86
patch_id: —
commit_hash: 5a81fdb8059c79fbf8d6b2ab1c765c930ac734ad
source_type: public_inbox
headline: Decode EVEX 0F38 4B by length
tldr: x86 disassembler explicitly decodes EVEX 0F38 4B instructions based on length.
author: Jan Beulich <jbeulich@sourceware.org>
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • x86
• disassembler
• evex
• amd
discussion_id_link: —
bugzilla_pr: —
url: https://inbox.sourceware.org/binutils-cvs/20261005091907.36A804BA2E1D@sourceware.org
date: 2026-10-05T00:00:00.000Z

This commit modifies the x86 disassembler to explicitly handle the length decoding for EVEX instructions with the 0F38 4B opcode. Previously, length handling for certain EVEX instructions relied on a general mechanism, but this change introduces a specific path for these ACE instructions.