From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:53287)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peter.maydell@linaro.org>) id 1anSui-00014B-1f
	for qemu-devel@nongnu.org; Tue, 05 Apr 2016 11:29:08 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <peter.maydell@linaro.org>) id 1anSuh-00062r-8H
	for qemu-devel@nongnu.org; Tue, 05 Apr 2016 11:29:07 -0400
Received: from mail-vk0-x234.google.com ([2607:f8b0:400c:c05::234]:35827)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <peter.maydell@linaro.org>) id 1anSuf-00062Z-Qd
	for qemu-devel@nongnu.org; Tue, 05 Apr 2016 11:29:06 -0400
Received: by mail-vk0-x234.google.com with SMTP id e6so22253028vkh.2
	for <qemu-devel@nongnu.org>; Tue, 05 Apr 2016 08:29:05 -0700 (PDT)
MIME-Version: 1.0
In-Reply-To: <1459777195-7907-3-git-send-email-vijayak@caviumnetworks.com>
References: <1459777195-7907-1-git-send-email-vijayak@caviumnetworks.com>
	<1459777195-7907-3-git-send-email-vijayak@caviumnetworks.com>
From: Peter Maydell <peter.maydell@linaro.org>
Date: Tue, 5 Apr 2016 16:28:45 +0100
Message-ID: <CAFEAcA-rV_rZHkOmbhMw+otPTPBSTZp_Ff_0ZrD_LpK2=TSAMQ@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8
Subject: Re: [Qemu-devel] [RFC PATCH v1 2/2] target-arm: Use Neon for zero
	checking
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Vijaya Kumar K <vijayak@caviumnetworks.com>
Cc: Prasun Kapoor <Prasun.Kapoor@caviumnetworks.com>, Vijay <vijayak@cavium.com>, qemu-arm <qemu-arm@nongnu.org>, QEMU Developers <qemu-devel@nongnu.org>, Vijay Kilari <vijay.kilari@gmail.com>

On 4 April 2016 at 14:39,  <vijayak@caviumnetworks.com> wrote:
> From: Vijay <vijayak@cavium.com>
>
> Use Neon instructions to perform zero checking of
> buffer. This is helps in reducing downtime during
> live migration.

One other comment I forgot:

> +#define NEON_VECTYPE               uint64x2_t

This is a 128-bit type...

> +static size_t buffer_find_nonzero_offset_neon(const void *buf, size_t len)
> +{
> +    size_t i;
> +    NEON_VECTYPE d0, d1, d2, d3, d4, d5, d6;
> +    NEON_VECTYPE d7, d8, d9, d10, d11, d12, d13, d14;

...so it's a bit confusing to use d0, d1, etc, which implies
a 64-bit value.

thanks
-- PMM