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From: Eric Blake <eblake@redhat.com>
To: Liang Li <liang.z.li@intel.com>, qemu-devel@nongnu.org
Cc: amit.shah@redhat.com, pbonzini@redhat.com, mst@redhat.com,
	quintela@redhat.com
Subject: Re: [Qemu-devel] [v2 0/2] add avx2 instruction optimization
Date: Mon, 9 Nov 2015 20:43:00 -0700	[thread overview]
Message-ID: <564167C4.2060702@redhat.com> (raw)
In-Reply-To: <1447123907-26750-1-git-send-email-liang.z.li@intel.com>

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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.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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  parent reply	other threads:[~2015-11-10  3:43 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-10  2:51 [Qemu-devel] [v2 0/2] add avx2 instruction optimization Liang Li
2015-11-10  2:51 ` [Qemu-devel] [v2 1/2] cutils: " Liang Li
2015-11-12 10:08   ` Paolo Bonzini
2015-11-12 10:12     ` Li, Liang Z
2015-11-12 11:30     ` Juan Quintela
2015-11-13  2:49     ` Li, Liang Z
2015-11-13  9:30       ` Paolo Bonzini
2015-11-12 14:43   ` Richard Henderson
2015-11-10  2:51 ` [Qemu-devel] [v2 2/2] configure: add options to config avx2 Liang Li
2015-11-10  3:43 ` Eric Blake [this message]
2015-11-10  5:48   ` [Qemu-devel] [v2 0/2] add avx2 instruction optimization Li, Liang Z
2015-11-10  9:13     ` Juan Quintela
2015-11-10  9:26       ` Li, Liang Z
2015-11-10  9:35         ` Paolo Bonzini
2015-11-10  9:41           ` Li, Liang Z
2015-11-10  9:50             ` Paolo Bonzini
2015-11-10  9:56               ` Li, Liang Z
2015-11-10 10:00                 ` Paolo Bonzini
2015-11-10 10:04                   ` Li, Liang Z
2015-11-12  2:49           ` Li, Liang Z
2015-11-12  8:43             ` Paolo Bonzini
2015-11-12  8:53               ` Li, Liang Z
2015-11-12  9:04                 ` Paolo Bonzini
2015-11-12  9:40                   ` Li, Liang Z
2015-11-12  9:45                     ` Paolo Bonzini
2015-11-12  9:53                       ` Li, Liang Z
2015-11-12 11:34                         ` Juan Quintela
2015-11-12 11:42                           ` Li, Liang Z
2015-11-12 19:56                             ` Dr. David Alan Gilbert
2015-11-12 20:20                               ` Eric Blake
2016-04-07 11:09                                 ` Dr. David Alan Gilbert
2016-04-07 12:54                                   ` Michael S. Tsirkin
2016-04-07 13:42                                     ` Dr. David Alan Gilbert
2016-04-07 13:54                                     ` Paolo Bonzini
2015-11-10  9:30       ` Paolo Bonzini

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