Landing: 107d2ad166d0

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Project / Subsystem

gcc / gcc/ira

Date

2026-06-12

Author

Stefan Schulze Frielinghaus

Commit

107d2ad166d09883b43ec1a5cf1e37c68b134a93

Source

github

Perf win

Breaking

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All attributes

project: gcc
subsystem: gcc/ira
patch_id: —
commit_hash: 107d2ad166d09883b43ec1a5cf1e37c68b134a93
source_type: github
headline: IRA now allows multiple uses within an instruction
tldr: The IRA pass in GCC has been updated to correctly handle situations where a register is used multiple times within a single instruction, preventing an assertio…
author: Stefan Schulze Frielinghaus
outcome: committed
performance_win: false
breaking_change: false
series_id: —
series_parts: []
tags: • ira
• bugfix
• rtl-optimization
discussion_id_link: —
bugzilla_pr: —
url: https://github.com/gcc-mirror/gcc/commit/107d2ad166d09883b43ec1a5cf1e37c68b134a93
date: 2026-06-12T00:00:00.000Z

The GCC Instruction Register Allocator (IRA) previously asserted when encountering multiple uses of a register within the same intermediate representation instruction. This change relaxes the assertion in combine_and_move_insns because the goal is to prevent a register from being used by multiple instructions, not multiple times within a single instruction. This fix addresses a scenario seen with asm_operands where a register was legitimately referenced multiple times.