Landing: 9e3a7b8d9de2

← All landings

Project / Subsystem

gcc / ira

Date

2026-09-04

Author

Yongqiang Tian

Commit

9e3a7b8d9de20e2c4fce3cdadf85dce468e7b107

Source

github

Perf win

Breaking

View on GitHub →

All attributes

project: gcc
subsystem: ira
patch_id: —
commit_hash: 9e3a7b8d9de20e2c4fce3cdadf85dce468e7b107
source_type: github
headline: IRA: Register allocation decision excludes debug instructions.
tldr: Register allocation decisions in IRA now ignore debug instructions, preventing unexpected code changes when debug info is enabled.
author: Yongqiang Tian
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • ira
• register allocation
• debug
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/9e3a7b8d9de20e2c4fce3cdadf85dce468e7b107
date: 2026-09-04T00:00:00.000Z

The Integrated Register Allocator (IRA) component’s decision to use the simple LRA (Local Register Allocation) now correctly excludes debug instructions. Previously, debug instructions consumed UIDs, potentially causing the threshold for simple LRA to be crossed and leading to different code generation. This change ensures the decision is based solely on the count of non-debug instructions.