Landing: 4015b65b038b

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Project / Subsystem

gcc / aarch64

Date

2026-09-18

Author

Richard Ball

Commit

4015b65b038bea050c7892aa4535020493cd7c66

Source

github

Perf win

Yes

Breaking

View on GitHub →

All attributes

project: gcc
subsystem: aarch64
patch_id: —
commit_hash: 4015b65b038bea050c7892aa4535020493cd7c66
source_type: github
headline: aarch64: Add support for FEAT_CMH atomic_fetch intrinsics
tldr: AArch64 support added for new atomic fetch operations with hints using FEAT_CMH extension.
author: Richard Ball
outcome: committed
performance_win: true
breaking_change: false
series_id: —
series_parts: []
tags: • aarch64
• atomic-operations
• intrinsics
• FEAT_CMH
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/4015b65b038bea050c7892aa4535020493cd7c66
date: 2026-09-18T00:00:00.000Z

GCC now supports new atomic fetch-with-hint intrinsics for the AArch64 architecture, leveraging the FEAT_CMH extension. This addition enables the use of new hints like SHUH and SHUH PH for atomic operations such as fetch-and-add, fetch-and-sub, fetch-and-or, fetch-and-xor, and fetch-and-and. Corresponding test cases have been added.