From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f169.google.com (mail-pf0-f169.google.com [209.85.192.169]) by dpdk.org (Postfix) with ESMTP id 148892BF3 for ; Thu, 31 Aug 2017 07:05:56 +0200 (CEST) Received: by mail-pf0-f169.google.com with SMTP id r62so25303791pfj.0 for ; Wed, 30 Aug 2017 22:05:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=fge9mBQlhRsYs4infyEzSfioLmAQqmZvhzF+eDS7JQs=; b=G8C6VYUVr92gqw/O0DiSBVbnf5bCNmNb3K+iBXsUkwPJ5iMZg2mZG8+GOAfuM21F3w aHHc9t0Z7yD/oomSF/p1Igu6G3XtfqY33z8FwiPwM/TyTPD1iTuVpGjn0MN60RUms61f ZCKaM8mk6tKd0vlRrg3CjhFiJRFkTX8gTPPbifmopbZQ8/PiMxwT26A8x4WNdpABIreX kyyGrnxSAbTF/bIaV2801OqHmRDrHEoTr5+stEQzeh/yLtJrv1HSAhGZroyUETbnZ9px yLoKYExRaT3JVpXxVAznfF3KszN055NFsIJ8KzEvk7IZenU+5HuqIl4UziZHWtDjDJWr sTjA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=fge9mBQlhRsYs4infyEzSfioLmAQqmZvhzF+eDS7JQs=; b=fdVJAQRQNduO4HasGSFAwZBZwULLCV6moaCf1K4itbSz23mf35nhIPCB0n6hqjKaaE 1R4AKHMjozrHLhiSbnqei69ARrnT1sJYrsmIUDa8zpA80i7GNTpGZy/E/F8bbX0FtWRn kGBzCTrc5+88MrsYwIQj/vk15h02Uc9Dus4r3sG0ZAG9cZIO9r21ROMD5YKRiYjYio3M pJpKaFLI9B/AMKQ8ykiYCJohFPfYkhcQFPFc3zOcIuLmW8PwmDP6UiwqPspDULH+yVSh Dn4EB1/CBMZMmgpCemQe0cca/57ou0s8p9Mg7iuJAl9cgz+zkZ/zoZNcE3sVdXeOPC0I StTw== X-Gm-Message-State: AHYfb5j2RdhxZSQZLSWM4jH2gaUOWTw56LaGqvBFW2EumOnTLqOA15pq 2rG6K1GaIZbaYTKw1Fu+RMajh45tWRgf X-Received: by 10.84.129.103 with SMTP id 94mr1256493plb.113.1504155955267; Wed, 30 Aug 2017 22:05:55 -0700 (PDT) MIME-Version: 1.0 Received: by 10.100.181.229 with HTTP; Wed, 30 Aug 2017 22:05:54 -0700 (PDT) Received: by 10.100.181.229 with HTTP; Wed, 30 Aug 2017 22:05:54 -0700 (PDT) In-Reply-To: <6A0DE07E22DDAD4C9103DF62FEBC09093B6A2D25@shsmsx102.ccr.corp.intel.com> References: <1503626773-184682-1-git-send-email-xiaoyun.li@intel.com> <1503626773-184682-2-git-send-email-xiaoyun.li@intel.com> <20170830110040.20b037e6@xeon-e3> <6A0DE07E22DDAD4C9103DF62FEBC09093B6A2D25@shsmsx102.ccr.corp.intel.com> From: Stephen Hemminger Date: Wed, 30 Aug 2017 22:05:54 -0700 Message-ID: To: "Lu, Wenzhuo" Cc: "Wang, Zhihong" , dev@dpdk.org, "Zhang, Qi Z" , "Li, Xiaoyun" , "Richardson, Bruce" Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-dev] [PATCH 1/3] eal/x86: run-time dispatch over memcpy X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 31 Aug 2017 05:05:57 -0000 I was referring to gcc multiversion https://gcc.gnu.org/wiki/FunctionMultiVersioning On Aug 30, 2017 6:24 PM, "Lu, Wenzhuo" wrote: > Hi Stephen, > > > > -----Original Message----- > > From: Stephen Hemminger [mailto:stephen@networkplumber.org] > > Sent: Thursday, August 31, 2017 2:01 AM > > To: Li, Xiaoyun > > Cc: Richardson, Bruce ; dev@dpdk.org; Lu, > > Wenzhuo ; Wang, Zhihong > > ; Zhang, Qi Z > > Subject: Re: [dpdk-dev] [PATCH 1/3] eal/x86: run-time dispatch over > memcpy > > > > On Fri, 25 Aug 2017 10:06:11 +0800 > > Xiaoyun Li wrote: > > > > > This patch dynamically selects functions of memcpy at run-time based > > > on CPU flags that current machine supports. This patch uses function > > > pointers which are bind to the relative functions at constrctor time. > > > To make AVX512 instructions pass compilation, enable the switch in > > > makefile. > > > > > > Signed-off-by: Xiaoyun Li > > > > Recent versions of GCC also have better ways to handle this. > I think the assumption of using the instructions is that we believe we can > do better than the compiler. If it turns out not, maybe we need to change > the instructions back to C. But it's another story. > >