From nobody Sun Jun 21 10:13:50 2026 X-Original-To: dev-commits-src-main@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4gjnHQ67Wmz6jR97; Sun, 21 Jun 2026 10:14:10 +0000 (UTC) (envelope-from kib@freebsd.org) Received: from kib.kiev.ua (kib.kiev.ua [IPv6:2001:470:d5e7:1::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4gjnHP660cz3H05; Sun, 21 Jun 2026 10:14:09 +0000 (UTC) (envelope-from kib@freebsd.org) Authentication-Results: mx1.freebsd.org; none Received: from tom.home (kib@localhost [127.0.0.1] (may be forged)) by kib.kiev.ua (8.18.1/8.18.1) with ESMTP id 65LADpY8093473; Sun, 21 Jun 2026 13:13:54 +0300 (EEST) (envelope-from kib@freebsd.org) DKIM-Filter: OpenDKIM Filter v2.10.3 kib.kiev.ua 65LADpY8093473 Received: (from kostik@localhost) by tom.home (8.18.1/8.18.1/Submit) id 65LADoR6093472; Sun, 21 Jun 2026 13:13:50 +0300 (EEST) (envelope-from kib@freebsd.org) X-Authentication-Warning: tom.home: kostik set sender to kib@freebsd.org using -f Date: Sun, 21 Jun 2026 13:13:50 +0300 From: Konstantin Belousov To: Faraz Vahedi Cc: Warner Losh , alc@freebsd.org, src-committers@freebsd.org, dev-commits-src-all@freebsd.org, dev-commits-src-main@freebsd.org Subject: Re: git: 9d87c1aac4a8 - main - libc: Add missing kill_dependency macro Message-ID: References: <6a35ddd4.24ba1.2ad9343d@gitrepo.freebsd.org> <9A21692F-0B53-4303-85A8-57784BFAF8DE@kfv.io> <33E8BFC4-EA46-41A7-B54F-1AADD3C19D9E@kfv.io> List-Id: Commit messages for the main branch of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-main List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-main@freebsd.org Sender: owner-dev-commits-src-main@FreeBSD.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Spam-Status: No, score=-2.9 required=5.0 tests=ALL_TRUSTED,BAYES_00 autolearn=ham autolearn_force=no version=4.0.2 X-Spam-Checker-Version: SpamAssassin 4.0.2 (2025-08-27) on tom.home X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[]; ASN(0.00)[asn:6939, ipnet:2001:470::/32, country:US] X-Rspamd-Queue-Id: 4gjnHP660cz3H05 X-Spamd-Bar: ---- X-Rspamd-Pre-Result: action=no action; module=replies; Message is reply to one we originated On Sat, Jun 20, 2026 at 11:50:50PM +0330, Faraz Vahedi wrote: > Hey, > > I see. I dug further into related proposals and the reasons why no > compiler today has implemented true data dependency tracking > and that they all basically map and promote consume to acquire. > The kill_dependency is also basically a no-op, and both compilers > optimise them identically. I did a few tests on my AArch64 box and > that's how I'm convinced, so I believe keeping the current form > could be ideal as it fully conforms to the standard and we're assured > that at least any conforming compiler would support it just fine and > there's no extension or non-standard tweak in it. On the other hand, > although adding a separate branch with the GCC style is possible, I > don't think that'd add any value but visual complications. > > Either way, whether dependency tracking changes drastically or this > very approach becomes obsolete, keeping our header as-is seems > safe for now. I am fine with it then. My concern was in subtle breakage of the code compiled with gcc. Thanks. > > Again, I should admit that despite my enthusiasm for compilers and > long-time personal studies of that field, I am by no means an expert > and can be wrong, or at least miss some corner cases I'm not aware > of, so please educate me if so. > > Yours, > Faraz