From unknown Sun Jun 22 08:04:51 2025 X-Loop: help-debbugs@gnu.org Subject: bug#47218: glibc 2.33's HWCAPS and GCC Function Multiversioning for performance Resent-From: =?UTF-8?Q?L=C3=A9o?= Le Bouter Original-Sender: "Debbugs-submit" Resent-CC: bug-guix@gnu.org Resent-Date: Wed, 17 Mar 2021 19:01:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: report 47218 X-GNU-PR-Package: guix X-GNU-PR-Keywords: To: 47218@debbugs.gnu.org X-Debbugs-Original-To: bug-guix@gnu.org Received: via spool by submit@debbugs.gnu.org id=B.161600760827451 (code B ref -1); Wed, 17 Mar 2021 19:01:01 +0000 Received: (at submit) by debbugs.gnu.org; 17 Mar 2021 19:00:08 +0000 Received: from localhost ([127.0.0.1]:43985 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lMbOp-00078e-Vw for submit@debbugs.gnu.org; Wed, 17 Mar 2021 15:00:08 -0400 Received: from lists.gnu.org ([209.51.188.17]:47220) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lMbOm-00077W-7I for submit@debbugs.gnu.org; Wed, 17 Mar 2021 15:00:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:46152) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lMbOl-0002bG-3z for bug-guix@gnu.org; Wed, 17 Mar 2021 15:00:03 -0400 Received: from mail.zaclys.net ([178.33.93.72]:38663) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lMbOh-0003Jx-5z for bug-guix@gnu.org; Wed, 17 Mar 2021 15:00:02 -0400 Received: from guix-xps.local (82-64-145-38.subs.proxad.net [82.64.145.38]) (authenticated bits=0) by mail.zaclys.net (8.14.7/8.14.7) with ESMTP id 12HIxu4m037720 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Wed, 17 Mar 2021 19:59:56 +0100 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.zaclys.net 12HIxu4m037720 Authentication-Results: mail.zaclys.net; dmarc=fail (p=reject dis=none) header.from=zaclys.net Authentication-Results: mail.zaclys.net; spf=fail smtp.mailfrom=lle-bout@zaclys.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zaclys.net; s=default; t=1616007596; bh=5MmbkdxlhYOUNez1TRStTpK4yxPqalr4rcxXVc6ntio=; h=Subject:From:To:Date:From; b=mknYsgP2dOkoEaYGVXwQXb4II1GG9qgxfwBc552BIHJNRR6J3Ptk6SnR07Im30UJ/ erUE7RKlw+DYfnSukAUVZqb1LNN0jjBbZYE8DYeAJwr9aYcqK1kd9s41JjrNBbempD nZI9KXGvB3Y/aHrxdtXsd6mgqTCKlgSOzvsJySvM= Message-ID: From: =?UTF-8?Q?L=C3=A9o?= Le Bouter Date: Wed, 17 Mar 2021 19:59:51 +0100 Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="=-Fin6oTue5EKmt0EG1/mg" User-Agent: Evolution 3.34.2 MIME-Version: 1.0 Received-SPF: pass client-ip=178.33.93.72; envelope-from=lle-bout@zaclys.net; helo=mail.zaclys.net X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-Spam-Score: -1.3 (-) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -2.3 (--) --=-Fin6oTue5EKmt0EG1/mg Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hello! Please see: -=20 https://www.gnu.org/software/libc/manual/html_mono/libc.html#Hardware-Capab= ility-Tunables - https://www.phoronix.com/scan.php?page=3Dnews_item&px=3Dglibc-hwcaps-RFC - https://gcc.gnu.org/onlinedocs/gcc/Function-Multiversioning.html This could help GNU Guix create binaries that include multiple code paths for several CPU features in the same binary and selecting the best at runtime when the binary is run. It is the best fit for GNU Guix because it means we can still use substitutes and profit from specialized optimizations without parameterized packages or each user adding "-march=3Dnative" to CFLAGS (breaking reproducibility). L=C3=A9o --=-Fin6oTue5EKmt0EG1/mg Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEFIvLi9gL+xax3g6RRaix6GvNEKYFAmBSUacACgkQRaix6GvN EKYaXg//bjhmZ3RppzYgPDgzt6CCl8EczplWiOTancTvz+wqSA6C6+k/Qmi3Ntor yiZjgpjbg5kPtsuav2BnVSUzy9XJnD4Ans0Y3/c3iwyJQloCp8Yf4xt9t30ayW2K DySVIKY3luD7T78OXVyD+crelzrM7P70vuiOSlTld9LO6oTQ/zFEbLBZGHzTeH9M UfMwH8t82PBddwnt6UkeqzcY2cleNKf8FyO7M2c7tZBBesVyMZWNaonJXfS7obtg ZlL+ZJWQk4Dn342kK2+TXG6lQZaudD4MF5VNPLeAPtBie1qQQa658ALwrcL1nA8l ZiNAe5pj4Wb8baRh+0EFtqVX4znNHbm+Xq5768x7Kfek8i6+BHgMufRyzGRJe761 5QYPahwGZlgPsIhSkmjXZNsknvASguKUZ2fmmXiInyC59inG4w29TQZFQ9wOe/cN 1RsQwB/H5QABjmTCCWutUe552Sf8BHUCCJHXvjg0yEsLMOv3Xo1jnF4D9o1DnFMu GRkC6aFmk+8QTD8AAwA+hEV6d53Uo+52w1AhwWoL591xvdEvGzXSlz88atFVYiAS jbMCRqZeqqTwXgfCJwuwMdNMph1d25D7TSxifGMVqGwsOS6ELgYvGrCcOEC2/0lA FKcT8clsa7XsZ6zil5Qs/cq13xH77tznLEh75sMdUsOzuWHvF+Y= =oLAa -----END PGP SIGNATURE----- --=-Fin6oTue5EKmt0EG1/mg-- From unknown Sun Jun 22 08:04:51 2025 X-Loop: help-debbugs@gnu.org Subject: bug#47218: glibc 2.33's HWCAPS and GCC Function Multiversioning for performance Resent-From: Ludovic =?UTF-8?Q?Court=C3=A8s?= Original-Sender: "Debbugs-submit" Resent-CC: bug-guix@gnu.org Resent-Date: Thu, 18 Mar 2021 13:18:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 47218 X-GNU-PR-Package: guix X-GNU-PR-Keywords: To: =?UTF-8?Q?L=C3=A9o?= Le Bouter Cc: 47218@debbugs.gnu.org Received: via spool by 47218-submit@debbugs.gnu.org id=B47218.161607347229291 (code B ref 47218); Thu, 18 Mar 2021 13:18:02 +0000 Received: (at 47218) by debbugs.gnu.org; 18 Mar 2021 13:17:52 +0000 Received: from localhost ([127.0.0.1]:45335 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lMsXA-0007cN-0q for submit@debbugs.gnu.org; Thu, 18 Mar 2021 09:17:52 -0400 Received: from mail3-relais-sop.national.inria.fr ([192.134.164.104]:22253) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lMsX8-0007c9-4Q for 47218@debbugs.gnu.org; Thu, 18 Mar 2021 09:17:50 -0400 IronPort-HdrOrdr: A9a23:ryT3vKOVhEfDB8BcTlGjsMiAIKoaSvp033AA3SlKJCB9WMqeisyogbAnzhfykjkcQzUNntqHNamGTxrnhPpIyKMWOqqvWxSjhXuwIOhZnO7f6hDpBiGWzIBg/Ih6dawWMrbNJHh8yf33+QypV+snqePnzImNpcPzi0hgVhtrbaYI1XYaNi++HldtTAdLQboVfaD92uN9qzCteWsaY62AbxE4dtPOqNHRmJXtbQRuPXEawTOThjCl4qOSKXSl9yoZOgkk/Z4f62Tf1yT26qK/2svLqSPh6w== X-IronPort-AV: E=Sophos;i="5.81,258,1610406000"; d="scan'208";a="376134145" Received: from 91-160-117-201.subs.proxad.net (HELO ribbon) ([91.160.117.201]) by mail3-relais-sop.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Mar 2021 14:17:43 +0100 From: Ludovic =?UTF-8?Q?Court=C3=A8s?= References: Date: Thu, 18 Mar 2021 14:17:42 +0100 In-Reply-To: ("=?UTF-8?Q?L=C3=A9o?= Le Bouter"'s message of "Wed, 17 Mar 2021 19:59:51 +0100") Message-ID: <87lfakr47d.fsf@gnu.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Spam-Score: -2.3 (--) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -3.3 (---) Hi L=C3=A9o, L=C3=A9o Le Bouter skribis: > Please see: > -=20 > https://www.gnu.org/software/libc/manual/html_mono/libc.html#Hardware-Cap= ability-Tunables > - https://www.phoronix.com/scan.php?page=3Dnews_item&px=3Dglibc-hwcaps-RFC > - https://gcc.gnu.org/onlinedocs/gcc/Function-Multiversioning.html > > This could help GNU Guix create binaries that include multiple code > paths for several CPU features in the same binary and selecting the > best at runtime when the binary is run. > > It is the best fit for GNU Guix because it means we can still use > substitutes and profit from specialized optimizations without > parameterized packages or each user adding "-march=3Dnative" to CFLAGS > (breaking reproducibility). For the record, we are well aware of these features and follow this very closely in particular in the context of Guix-HPC: https://hpc.guix.info/blog/2018/01/pre-built-binaries-vs-performance/ It seems to me that this bug report is not actionable though. Unless there are concrete steps you=E2=80=99d like to suggest, I propose to close = this issue. Thanks, Ludo=E2=80=99. From debbugs-submit-bounces@debbugs.gnu.org Mon Mar 29 17:40:19 2021 Received: (at control) by debbugs.gnu.org; 29 Mar 2021 21:40:19 +0000 Received: from localhost ([127.0.0.1]:49790 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lQzcR-0006sa-0K for submit@debbugs.gnu.org; Mon, 29 Mar 2021 17:40:19 -0400 Received: from eggs.gnu.org ([209.51.188.92]:45596) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1lQzcP-0006sI-5V for control@debbugs.gnu.org; Mon, 29 Mar 2021 17:40:17 -0400 Received: from fencepost.gnu.org ([2001:470:142:3::e]:52581) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lQzcJ-0000hE-Tk for control@debbugs.gnu.org; Mon, 29 Mar 2021 17:40:11 -0400 Received: from [2a01:e0a:1d:7270:af76:b9b:ca24:c465] (port=50150 helo=ribbon) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1lQzcC-0006vv-IW for control@debbugs.gnu.org; Mon, 29 Mar 2021 17:40:05 -0400 Date: Mon, 29 Mar 2021 23:40:03 +0200 Message-Id: <87ft0dljv0.fsf@gnu.org> To: control@debbugs.gnu.org From: =?utf-8?Q?Ludovic_Court=C3=A8s?= Subject: control message for bug #47218 MIME-version: 1.0 Content-type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Spam-Score: -0.7 (/) X-Debbugs-Envelope-To: control X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -1.7 (-) tags 47218 notabug close 47218 quit