Landing: cfc8ba7fa91e

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Project / Subsystem

gcc / regrename

Date

2026-07-01

Author

Andrew Stubbs

Commit

cfc8ba7fa91eb7bf12fb7cd01542ddee2c337fb0

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: regrename
patch_id: —
commit_hash: cfc8ba7fa91eb7bf12fb7cd01542ddee2c337fb0
source_type: github
headline: Register renamer handles memory addresses with segments
tldr: Fixes register renaming for memory addresses containing explicit segment components.
author: Andrew Stubbs
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • regrename
• optimization
• assembly
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/cfc8ba7fa91eb7bf12fb7cd01542ddee2c337fb0
date: 2026-07-01T00:00:00.000Z

The register rename pass in GCC has been updated to correctly handle memory addresses that include explicit segment information. Prior to this change, the pass could misidentify register components in segmented addresses, potentially corrupting 64-bit addresses on targets with 32-bit registers by placing address parts in non-contiguous registers. The fix in regrename.cc ensures that arbitrary UNSPECs used as segments are properly recursed into.