From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id C0F7BADBE for ; Wed, 30 Jul 2014 21:01:12 +0200 (CEST) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP; 30 Jul 2014 12:03:03 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,766,1400050800"; d="scan'208";a="577844298" Received: from unknown (HELO localhost.localdomain) ([134.134.172.151]) by fmsmga002.fm.intel.com with ESMTP; 30 Jul 2014 12:00:17 -0700 Date: Wed, 30 Jul 2014 11:59:03 -0700 From: Bruce Richardson To: Neil Horman Message-ID: <20140730185902.GA6420@localhost.localdomain> References: <1406665466-29654-1-git-send-email-nhorman@tuxdriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1406665466-29654-1-git-send-email-nhorman@tuxdriver.com> Organization: Intel Shannon Limited. Registered in Ireland. Registered Office: Collinstown Industrial Park, Leixlip, County Kildare. Registered Number: 308263. Business address: Dromore House, East Park, Shannon, Co. Clare. User-Agent: Mutt/1.5.21 (2010-09-15) Cc: dev@dpdk.org Subject: Re: [dpdk-dev] [PATCH 0/2] dpdk: Allow for dynamic enablement of some isolated features X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 30 Jul 2014 19:01:13 -0000 On Tue, Jul 29, 2014 at 04:24:24PM -0400, Neil Horman wrote: > Hey all- > I've been trying to update the fedora dpdk package to support VFIO > enabled drivers and ran into a problem in which ixgbe didn't compile because the > rxtx_vec code uses sse4.2 instruction intrinsics, which aren't supported in the > default config I have. I tried to remedy this by replacing the intrinsics with > the __builtin macros, but it was pointed out (correctly), that this doesn't work > properly. So this is my second attempt, which I actually like a bit better. I > noted that code that uses intrinsics (ixgbe and the acl library), don't need to > have those instructions turned on build-wide. Rather, we can just enable the > instructions in the specific code we want to build with support for that, and > test for instruction support dynamically at run time. This allows me to build > the dpdk for a generic platform, but in such a way that some optimizations can > be used if the executing cpu supports them at run time. > > Signed-off-by: Neil Horman > CC: Thomas Monjalon > I'd prefer if a solution could be found based off your original patch set, as it gives us more chance to deprecate the older code paths in future. Looking at the Intel Intrinsics Guide site online, it shows that the _mm_shuffle_epi8 intrinsic came in with SSSE3, rather than SSE4.x, and so should be available on all 64-bit systems, I believe. The popcount intrinsic is newer, but it's a much more basic instruction so hopefully the __builtin should work for that. Regards, /Bruce