From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by dpdk.org (Postfix) with ESMTP id D9E0B199A9; Thu, 7 Sep 2017 10:56:44 +0200 (CEST) Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga105.jf.intel.com with ESMTP; 07 Sep 2017 01:56:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.42,357,1500966000"; d="scan'208";a="148545613" Received: from bricha3-mobl3.ger.corp.intel.com ([10.237.221.24]) by fmsmga005.fm.intel.com with SMTP; 07 Sep 2017 01:56:41 -0700 Received: by (sSMTP sendmail emulation); Thu, 07 Sep 2017 09:56:41 +0100 Date: Thu, 7 Sep 2017 09:56:40 +0100 From: Bruce Richardson To: Xiaoyun Li Cc: dev@dpdk.org, helin.zhang@intel.com, stable@dpdk.org Message-ID: <20170907085640.GA24764@bricha3-MOBL3.ger.corp.intel.com> References: <1504773317-2042-1-git-send-email-xiaoyun.li@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1504773317-2042-1-git-send-email-xiaoyun.li@intel.com> Organization: Intel Research and =?iso-8859-1?Q?De=ACvel?= =?iso-8859-1?Q?opment?= Ireland Ltd. User-Agent: Mutt/1.8.3 (2017-05-23) Subject: Re: [dpdk-stable] [PATCH] mk: fix compiling error for atom target X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 Sep 2017 08:56:45 -0000 On Thu, Sep 07, 2017 at 04:35:17PM +0800, Xiaoyun Li wrote: > GCC thinks target atom doesn't support SSE4.2 and SSE4 is now part of > minimum requirements for DPDK on x86. So there are compiling errors when > cross-compiling for target atom. And in fact, the atom supports SSE4 now. > This patch fixes this issue. > > Fixes: 5ea4d4688dce ("net/ixgbe: remove fallback code for x86 non-SSE4") > Cc: stable@dpdk.org > > Signed-off-by: Xiaoyun Li The -march=atom flag is for older atom CPUs, and is no longer advertised by gcc, since all -march flags now correspond to the actual core microarchitecture used. [man gcc on Fedora 26, no longer lists atom as a valid march value, though it's probably still accepted for backward compatibility]. The direct replacement for atom is "bonnell", which does not have SSE4.2 support, so we should not use. What we do support is later atoms, so the architecture targets for atom should be "-march=silvermont". This automatically includes sse4 support so no additional flags needed. Note: I previously had this discussion with Neil on-list, but forgot to do the follow-up work agreed on. See: https://www.mail-archive.com/dev@dpdk.org/msg72629.html The agreed plan was to remove atom as a target for DPDK builds and add a "silvermont" replacement instead. If you have time, perhaps you could look at doing that instead of this fix? /Bruce > --- > mk/machine/atm/rte.vars.mk | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mk/machine/atm/rte.vars.mk b/mk/machine/atm/rte.vars.mk > index cfed110..a6899d9 100644 > --- a/mk/machine/atm/rte.vars.mk > +++ b/mk/machine/atm/rte.vars.mk > @@ -56,3 +56,5 @@ > # CPU_ASFLAGS = > > MACHINE_CFLAGS = -march=atom > + > +MACHINE_CFLAGS += -msse4.2 > -- > 2.7.4 >