Landing: cefcc09723c3

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Project / Subsystem

gcc / aarch64

Date

2026-05-06

Author

Soumya AR

Commit

cefcc09723c363f61e65f9a2774f82258fc43474

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: aarch64
patch_id: —
commit_hash: cefcc09723c363f61e65f9a2774f82258fc43474
source_type: github
headline: AArch64: Move pass_narrow_gp_writes before pass_free_cfg to fix DF state.
tldr: The narrow_gp_writes pass now runs before pass_free_cfg in GCC for AArch64, preventing stale dataflow (DF) state issues.
author: Soumya AR
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • aarch64
• optimization
• dataflow
• bugfix
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/cefcc09723c363f61e65f9a2774f82258fc43474
date: 2026-05-06T00:00:00.000Z

The narrow_gp_writes pass in GCC for AArch64 architectures uses RTL-SSA and updates dataflow (DF) state. The pass_free_cfg pass was clearing per-instruction pointers before narrow_gp_writes ran, leading to stale DF information and potentially incorrect optimizations. Moving narrow_gp_writes to run before pass_free_cfg resolves this issue.