Landing: 2f74d0ef9daf

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Project / Subsystem

gcc / amdgcn

Date

2026-09-03

Author

Andrew Stubbs

Commit

2f74d0ef9dafed5483bbb42d67a387c36309a461

Source

github

Perf win

Yes

Breaking

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All attributes

project: gcc
subsystem: amdgcn
patch_id: —
commit_hash: 2f74d0ef9dafed5483bbb42d67a387c36309a461
source_type: github
headline: amdgcn: Improve DImode "not" instruction.
tldr: The AMDGCN backend now uses a more efficient instruction for DImode 'not' operations.
author: Andrew Stubbs
outcome: committed
performance_win: true
breaking_change: false
series_id: —
series_parts: []
tags: • amdgcn
• optimization
• backend
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/2f74d0ef9dafed5483bbb42d67a387c36309a461
date: 2026-09-03T00:00:00.000Z

The AMDGCN backend’s handling of the bitwise NOT operation for DImode (64-bit integers) has been improved. Instead of requiring two instructions, it now uses the s_not_b64 instruction, making the operation more efficient.