Landing: d956c5ad043f

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Project / Subsystem

gcc / aarch64

Date

2026-09-15

Author

Tamar Christina

Commit

d956c5ad043f767bcde25e09ec48917afb2c8e8c

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: aarch64
patch_id: —
commit_hash: d956c5ad043f767bcde25e09ec48917afb2c8e8c
source_type: github
headline: AArch64: Fix FFR widening loads bug with alternate approach
tldr: Resolves a compiler bug affecting AArch64 SVE widening loads by restructuring FFR update handling.
author: Tamar Christina
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • AArch64
• SVE
• vectorization
• optimization
• compiler bug
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/d956c5ad043f767bcde25e09ec48917afb2c8e8c
date: 2026-09-15T00:00:00.000Z

This commit introduces an alternative fix for a bug in the AArch64 SVE (Scalable Vector Extension) handling, specifically related to fused-first-register (FFR) widening loads and common subexpression elimination (CSE). The previous fix interfered with FFR widening loads. This new approach moves the SET instruction for the source operand into the update_ffr token, resolving the CSE issue while maintaining support for vectorizer-generated widening loads and improving maintainability.