Re: [RFC] Builtins for C++26 integer atomic reductions

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Project / Subsystem

gcc / gcc

Date

2026-04-23

Proposer

Matthew Malcomson <mmalcomson@nvidia.com>

Source type

public_inbox

Consensus

Proposed

Sentiment

—/10

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All attributes

project: gcc
subsystem: gcc
patch_id: —
discussion_id: 9f3b700b-23dd-4eef-9aae-7fdf2e28e2f1@nvidia.com
source_type: public_inbox
title: Re: [RFC] Builtins for C++26 integer atomic reductions
headline: Builtins for C++26 integer atomic reductions
tldr: The author provides a detailed explanation with litmus tests demonstrating the necessity of new builtins for C++26 integer atomic reductions due to memory mode…
proposer: Matthew Malcomson <mmalcomson@nvidia.com>
consensus: Proposed
outcome: proposed
sentiment_score: —
technical_tradeoffs: []
series_id: —
series_role: standalone
series_parts: []
tags: []
url: https://inbox.sourceware.org/gcc/9f3b700b-23dd-4eef-9aae-7fdf2e28e2f1@nvidia.com
bugzilla_url: —
date: 2026-04-23T00:00:00.000Z

Re: [RFC] Builtins for C++26 integer atomic reductions

The author provides a detailed explanation of why new builtins are required for C++26 integer atomic reductions. They use litmus tests to demonstrate the memory model semantics that necessitate these new builtins. This discussion highlights the complexities of ensuring correct atomic operations in multi-threaded C++ code.