From patchwork Tue Mar 12 15:50:31 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Lieven X-Patchwork-Id: 227060 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 5E2A02C0299 for ; Wed, 13 Mar 2013 02:51:31 +1100 (EST) Received: from localhost ([::1]:53420 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UFRU9-0002IK-ID for incoming@patchwork.ozlabs.org; Tue, 12 Mar 2013 11:51:29 -0400 Received: from eggs.gnu.org ([208.118.235.92]:56446) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UFRTJ-00013s-3a for qemu-devel@nongnu.org; Tue, 12 Mar 2013 11:50:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UFRTB-0002aj-Lp for qemu-devel@nongnu.org; Tue, 12 Mar 2013 11:50:35 -0400 Received: from ssl.dlhnet.de ([91.198.192.8]:46020 helo=ssl.dlh.net) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UFRTB-0002ad-Fb for qemu-devel@nongnu.org; Tue, 12 Mar 2013 11:50:29 -0400 Received: from localhost (localhost [127.0.0.1]) by ssl.dlh.net (Postfix) with ESMTP id 0120F14540E; Tue, 12 Mar 2013 16:50:29 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at ssl.dlh.net Received: from ssl.dlh.net ([127.0.0.1]) by localhost (ssl.dlh.net [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id NsnzqGeKlSg8; Tue, 12 Mar 2013 16:50:28 +0100 (CET) Received: from [172.21.12.60] (unknown [82.141.1.226]) by ssl.dlh.net (Postfix) with ESMTPSA id AFB0B13F711; Tue, 12 Mar 2013 16:50:28 +0100 (CET) Message-ID: <513F4EC7.6010109@dlhnet.de> Date: Tue, 12 Mar 2013 16:50:31 +0100 From: Peter Lieven User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130221 Thunderbird/17.0.3 MIME-Version: 1.0 To: "qemu-devel@nongnu.org" X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 91.198.192.8 Cc: Kevin Wolf , Paolo Bonzini , Orit Wasserman , Stefan Hajnoczi Subject: [Qemu-devel] [RFC][PATCH 4/9] buffer_is_zero: use vector optimizations if possible X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org performance gain on SSE2 is approx. 20-25%. altivec is not tested. performance for unsigned long arithmetic is unchanged. Signed-off-by: Peter Lieven --- util/cutils.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/util/cutils.c b/util/cutils.c index a09d8e8..23f0cd6 100644 --- a/util/cutils.c +++ b/util/cutils.c @@ -186,6 +186,11 @@ bool buffer_is_zero(const void *buf, size_t len) * latency. */ + if (((uintptr_t) buf) % sizeof(VECTYPE) == 0 + && len % 8*sizeof(VECTYPE) == 0) { + return buffer_find_nonzero_offset(buf, len)==len; + } + size_t i; long d0, d1, d2, d3; const long * const data = buf;