Landing: 8ab2af4964f4

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Project / Subsystem

gcc / aarch64

Date

2026-09-02

Author

Richard Earnshaw

Commit

8ab2af4964f41248c3b1330f331a78ba6b5a6cc0

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: aarch64
patch_id: —
commit_hash: 8ab2af4964f41248c3b1330f331a78ba6b5a6cc0
source_type: github
headline: aarch64: Fixes for 'overflow' instruction patterns improve code generation.
tldr: Aarch64 instruction patterns for overflow checks with MINUS and NEG were corrected, fixing an ICE and improving optimization.
author: Richard Earnshaw
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • aarch64
• optimization
• bugfix
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/8ab2af4964f41248c3b1330f331a78ba6b5a6cc0
date: 2026-09-02T00:00:00.000Z

This commit rectifies several issues with AArch64 ‘overflow’ instruction patterns, specifically for MINUS and NEG operations. It corrects the selection of the CCmode for overflow checks, ensures patterns are in canonical form for better optimization by the ‘combine’ pass, and fixes an invalid output template that caused an ICE.