From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 80C7946482; Wed, 26 Mar 2025 19:07:02 +0100 (CET) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 3F0C04064A; Wed, 26 Mar 2025 19:07:02 +0100 (CET) Received: from dkmailrelay1.smartsharesystems.com (smartserver.smartsharesystems.com [77.243.40.215]) by mails.dpdk.org (Postfix) with ESMTP id 109DE402E3; Wed, 26 Mar 2025 19:07:01 +0100 (CET) Received: from smartserver.smartsharesystems.com (smartserver.smartsharesys.local [192.168.4.10]) by dkmailrelay1.smartsharesystems.com (Postfix) with ESMTP id D58D02064E; Wed, 26 Mar 2025 19:07:00 +0100 (CET) Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Subject: RE: [RFC PATCH] build: reduce use of AVX compiler flags X-MimeOLE: Produced By Microsoft Exchange V6.5 Date: Wed, 26 Mar 2025 19:06:58 +0100 Message-ID: <98CBD80474FA8B44BF855DF32C47DC35E9FB76@smartserver.smartshare.dk> In-Reply-To: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [RFC PATCH] build: reduce use of AVX compiler flags Thread-Index: Adueaz5wiwZQ0oo3S7KJT1pyloUmBwACwotA References: <20250325172215.3360590-1-bruce.richardson@intel.com> From: =?iso-8859-1?Q?Morten_Br=F8rup?= To: "Bruce Richardson" , Cc: X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org > From: Bruce Richardson [mailto:bruce.richardson@intel.com] > Sent: Wednesday, 26 March 2025 17.22 >=20 > On Tue, Mar 25, 2025 at 05:22:15PM +0000, Bruce Richardson wrote: > > When doing a build for a target that already has the instruction = sets > > for AVX2/AVX512 enabled, skip emitting the AVX compiler flags, or = the > > skylake-avx512 '-march' flags, as they are unnecessary. Instead, = when > > the default flags produce the desired output, just use them > unmodified. > > > > Depends-on: series-34915 ("remove component-specific logic for AVX > builds") > > > > Signed-off-by: Bruce Richardson > > --- > > > > This patchset depends on the previous AVX rework. However, sending = it > > separately as a new RFC because it effectively increases the minimum > > compiler versions needed for x86 builds - from GCC 5 to 6, and > > Clang 3.6 to 3.9. > > > > For now, I've just documented that as an additional note in the GSG > that > > these versions are recommended, but it would be simpler if we could > just > > set them as the required minimum baseline (at least in the docs). > > > > Feedback on these compiler version requirements welcome. > > >=20 > +techboard >=20 > Ping for a little bit of feedback for this. Are we ok to bump the > minimum > compiler versions as described above, or will I continue with the > approach > in this RFC of keeping the minimum and just recommending the higher > versions for x86 platforms? >=20 > For reference GCC 6.1 was released April 2016[1], and, Clang 3.9 was > released Sept 2016[2] >=20 > /Bruce >=20 > [1] https://gcc.gnu.org/gcc-6/ > [2] https://releases.llvm.org/ Considering GCC versions shipped with RHEL [3]... We kind of support RHEL 7, but we already require a newer compiler (GCC = 5) than shipped with RHEL 7 (GCC 4.8). RHEL 8 ships with GCC 8, which was released in May 2018 [4]. Maybe we = can jump to GCC 8? BTW, we should also apply the same principle I argued [5] should apply = for upgrading the Kernel requirements: There should be a need for = specific feature or similar - which there is with your patch - and the = details should be mentioned in the release notes. [3]: https://access.redhat.com/solutions/19458 [4]: https://gcc.gnu.org/gcc-8/ [5]: = https://inbox.dpdk.org/dev/CAMEVEZutf4sJ=3DEQFONw_bJW0tGTWqTbF_Tk_y38qzBL= ccco46Q@mail.gmail.com/T/#me7c8f1dbe4331ccf232d43512d6ddb51458c568a