From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 553FAA04B0; Fri, 7 Aug 2020 15:48:49 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 6D0012B87; Fri, 7 Aug 2020 15:48:48 +0200 (CEST) Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com [66.111.4.28]) by dpdk.org (Postfix) with ESMTP id 621611DBF; Fri, 7 Aug 2020 15:48:47 +0200 (CEST) Received: from compute7.internal (compute7.nyi.internal [10.202.2.47]) by mailout.nyi.internal (Postfix) with ESMTP id BCD2F5C00C3; Fri, 7 Aug 2020 09:48:46 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute7.internal (MEProxy); Fri, 07 Aug 2020 09:48:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding:content-type; s=fm1; bh= Vr7NZXmCzrcwE5SlcFGNAMgPAtq/E8Q2kd46uiKMQ4k=; b=hzputR6F83iOxNf3 l59kpUSDCVL5XNTsqEO12YYfqGmEMZN7LeFum3biKr3aJ/aw6jQ2gGGexHliO/Ab 3FaQND+mEKp+olNaTU6TIUxrpOM3iKoae2gUCXc3NyzdFZ/F7zZtnEvEcoYOcSui TQ3Vk2p+H7HO9qzXX7LUCRQ8QBk5Kyhqt3blG4ur7nD+kWIMI7jyavbzs5PfCT4c sULq9t2h9Xws1tPoyy1N9qVudUVKLkODttIeJTmG6fQ2sdaeQDLUANPmKvqu/kSk DhWZ2XEorFZFCADoE+xT+4gckPiI9xJeKr/MRxlSoNYz6/wNVhGoXS+QSDSI4nIT hIEFQA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm3; bh=Vr7NZXmCzrcwE5SlcFGNAMgPAtq/E8Q2kd46uiKMQ 4k=; b=WxKOI6mudAIy8OooBdJ/HpO22B7PgtYT0JDnJL7wMjfQ9PUDvGWCIA14v xdw9yref1SqdvjlY5XD28mafZl5LBDYNeIaeZWRrIAOKvGPbNFbE1G1hCj7R/pHM Ne+bO95pevL0RFCHFQr3FOj9/QjP+EIIPyFH1mQUHNwHDBG8udRFOSZovP5I5JWU dkOb5TP+DYwSkJXYpkq1WFKZ0AoiIrHYlj0PqN7VhIK3FIaeCFwDaaqpt7y80qtw Xh/rahWSTZ5kO+yPXrCjrep7ZbCfo71gEFbO8hj3sDf9AGGzluKZOgHWUjECw44y 6tczCWxxZNMTVJOYCH/9IGegmcRjQ== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduiedrkedvgdeiiecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefhvffufffkjghfggfgtgesthfuredttddtvdenucfhrhhomhepvfhhohhmrghs ucfoohhnjhgrlhhonhcuoehthhhomhgrshesmhhonhhjrghlohhnrdhnvghtqeenucggtf frrghtthgvrhhnpedugefgvdefudfftdefgeelgffhueekgfffhfeujedtteeutdejueei iedvffegheenucfkphepleefrdeirddugeelrdduudegnecuvehluhhsthgvrhfuihiivg eptdenucfrrghrrghmpehmrghilhhfrhhomhepthhhohhmrghssehmohhnjhgrlhhonhdr nhgvth X-ME-Proxy: Received: from xps.localnet (114.149.6.93.rev.sfr.net [93.6.149.114]) by mail.messagingengine.com (Postfix) with ESMTPA id 9DEBF328005E; Fri, 7 Aug 2020 09:48:45 -0400 (EDT) From: Thomas Monjalon To: Bruce Richardson Cc: dev@dpdk.org, techboard@dpdk.org, Ferruh Yigit Date: Fri, 07 Aug 2020 15:48:43 +0200 Message-ID: <2289852.h2yjUt0C1Z@thomas> In-Reply-To: <27d08eb2-5f66-e385-3d05-39ac317ece89@intel.com> References: <20200805142141.32337-1-bruce.richardson@intel.com> <20200805164504.GE1716@bricha3-MOBL.ger.corp.intel.com> <27d08eb2-5f66-e385-3d05-39ac317ece89@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [dpdk-dev] [dpdk-techboard] [PATCH 1/1] doc: add deprecation notice for CPU build flags 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: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 06/08/2020 23:41, Ferruh Yigit: > On 8/5/2020 5:45 PM, Bruce Richardson wrote: > > On Wed, Aug 05, 2020 at 05:15:31PM +0200, Thomas Monjalon wrote: > >> 05/08/2020 17:07, Bruce Richardson: > >>> On Wed, Aug 05, 2020 at 04:57:42PM +0200, Thomas Monjalon wrote: > >>>> 05/08/2020 16:21, Bruce Richardson: > >>>>> The RTE_MACHINE_CPUFLAGS_* macros in DPDK build just duplicate info from > >>>>> the compiler macros, so we can remove them and just use the compiler > >>>>> versions directly. > >>>>> > >>>>> Signed-off-by: Bruce Richardson > >>>>> --- > >>>>> --- a/doc/guides/rel_notes/deprecation.rst > >>>>> +++ b/doc/guides/rel_notes/deprecation.rst > >>>>> +* build macros: The macros defining RTE_MACHINE_CPUFLAG_* will be removed > >>>>> + from the build. The information provided by these macros is available > >>>>> + through standard compiler macros. For example, RTE_MACHINE_CPUFLAG_SSE3 > >>>>> + duplicates the compiler-provided macro __SSE3__. > >>>> > >>>> I see 2 advantages of having alias: > >>>> - if 2 compilers differ, we can manage > >>>> - we can find all such macros with grep RTE_MACHINE_CPUFLAG > >>>> > >>> > >>> Sure, if you think it's worthwhile keeping them, we can do so. It's just > >>> right now they seem to be largely a waste of space. For #2, I'm not sure > >>> when we would want to grep for them all, except possibly to remove them. > >>> :-) > >> > >> For instance, in a lib, I grep where we have CPU specific code. > >> > >> We probably need more opinions, I can change my mind. > >> > > Yes, we need some more opinions here. > > > > For the above point, yes it's useful to be able to grep for these things, > > but it does assume that everybody uses the DPDK-defines and doesn't use the > > compiler ones directly. There are a few instances where there seems to be > > x86, ARM or PPC compiler flags already directly used in the code. > > > > As well as brevity, the other big reason I see for removing them is to > > avoid having to maintain these lists of flags for future use. Right now, > > with -march=skylake-avx512, gcc will define 7 different AVX feature flags. > > DPDK, on the other hand, only provides equivalent defines for 3 of them. > > We have no automatic way of pulling all newly added flags from gcc/clang > > into our build, so we just add them on an as-needed basis, which makes it > > more awkward for those adding new features that may depend on the flags. If > > we always try to add in all flags to keep things in sync, we are just > > duplicating the efforts the compiler authors have already done for us, and > > wasting the effort for those flags that are unused. > > > > Sounds reasonable, > > Acked-by: Ferruh Yigit Applied