From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41320) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zvzpu-00084W-V4 for qemu-devel@nongnu.org; Mon, 09 Nov 2015 22:43:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zvzps-00014b-8i for qemu-devel@nongnu.org; Mon, 09 Nov 2015 22:43:10 -0500 Received: from mx1.redhat.com ([209.132.183.28]:34850) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zvzps-00014X-2y for qemu-devel@nongnu.org; Mon, 09 Nov 2015 22:43:08 -0500 References: <1447123907-26750-1-git-send-email-liang.z.li@intel.com> From: Eric Blake Message-ID: <564167C4.2060702@redhat.com> Date: Mon, 9 Nov 2015 20:43:00 -0700 MIME-Version: 1.0 In-Reply-To: <1447123907-26750-1-git-send-email-liang.z.li@intel.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="4SGVI7bqDnCI8Nrp1UF4S9rqnlhO4qIIJ" Subject: Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Liang Li , qemu-devel@nongnu.org Cc: amit.shah@redhat.com, pbonzini@redhat.com, mst@redhat.com, quintela@redhat.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --4SGVI7bqDnCI8Nrp1UF4S9rqnlhO4qIIJ Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 11/09/2015 07:51 PM, Liang Li wrote: > buffer_find_nonzero_offset() is a hot function during live migration. > Now it use SSE2 intructions for optimization. For platform supports > AVX2 instructions, use the AVX2 instructions for optimization can help > to improve the performance about 30% comparing to SSE2. Rather than trying to cater to multiple assembly instruction implementations ourselves, have you tried taking the ideas in this earlier thread? https://lists.gnu.org/archive/html/qemu-devel/2015-10/msg05298.html Ideally, libc's memcmp() will already be using the most efficient assembly instructions without us having to reproduce the work of picking the instructions that work best. --=20 Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org --4SGVI7bqDnCI8Nrp1UF4S9rqnlhO4qIIJ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCAAGBQJWQWfEAAoJEKeha0olJ0NqrkAH/1PKWaI23u/mja0+Cq/VL2RD zBEPH11D2KmBCX0CHxBL2Lu3LMtWq4gI6O9ANjpRtix1BRTwRQ1HsVKwuGRu4Xwi qzefQKjh4qVgdi/zAtGNY6jyztPne5HBRfs+HO9eQkReJd+T7Kc6lvc+EzVA4TTg ue1XMHOhg+XJg3qmdE5Tbj2W6Tp9Ak6t52x61snCV0skmrCGHnF4aXE33IeC1J+s oohPptPAqUgNTq4794gTEJ3PkEKQhLlLdB3RK+7eBtAqr0PAwNQZoHJz0GGzsbKn ZDO1WmVq6Vbk062rNUQ4omiUAhJlwm5h1vAWKB3Onl4IBr+5fsi2sARBBevk2uw= =KVwP -----END PGP SIGNATURE----- --4SGVI7bqDnCI8Nrp1UF4S9rqnlhO4qIIJ--