Landing: 1e804ce1c828

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Project / Subsystem

gcc / common, x86

Date

2026-09-12

Author

Iain Sandoe

Commit

1e804ce1c82809ce573217f0c675a0f3731d9199

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: common, x86
patch_id: —
commit_hash: 1e804ce1c82809ce573217f0c675a0f3731d9199
source_type: github
headline: Darwin queries kernel for AVX512 support.
tldr: Darwin's CPU information now queries the kernel for AVX512 availability due to lazy state enabling.
author: Iain Sandoe
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • x86
• Darwin
• AVX512
• CPU detection
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/1e804ce1c82809ce573217f0c675a0f3731d9199
date: 2026-09-12T00:00:00.000Z

GCC’s common x86 configuration on Darwin now queries the kernel for AVX512 support, as the operating system enables this state lazily. Reading XCR0 directly is unreliable in this context because the state may not be initialized when needed by constructors. This change ensures accurate detection of AVX512 capabilities.