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 1B3B8A04A9; Thu, 6 Aug 2020 23:41:33 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 0BC4C2BF2; Thu, 6 Aug 2020 23:41:32 +0200 (CEST) Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by dpdk.org (Postfix) with ESMTP id D17402BF1; Thu, 6 Aug 2020 23:41:29 +0200 (CEST) IronPort-SDR: GzGRRMKTmHhVxjclOr7l48pMZNNhAZ3XrP86rSutveOpx4OcSldSLMfVzpXOg87UoYVQox50Gr azlDXQlyUXXg== X-IronPort-AV: E=McAfee;i="6000,8403,9705"; a="133016802" X-IronPort-AV: E=Sophos;i="5.75,443,1589266800"; d="scan'208";a="133016802" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Aug 2020 14:41:28 -0700 IronPort-SDR: Hb9H+mtle2AL05hfr+WGoF3OmXDg27tWdnaqKQYqt5oMdSuSD/3GzNc2wCjZIgwrucDWM7q00C 3Xcnf3gle42Q== X-IronPort-AV: E=Sophos;i="5.75,443,1589266800"; d="scan'208";a="468007606" Received: from fyigit-mobl.ger.corp.intel.com (HELO [10.213.255.242]) ([10.213.255.242]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Aug 2020 14:41:27 -0700 To: Bruce Richardson , Thomas Monjalon Cc: dev@dpdk.org, techboard@dpdk.org References: <20200805142141.32337-1-bruce.richardson@intel.com> <2844470.HTv9E7uqEf@thomas> <20200805150741.GD1716@bricha3-MOBL.ger.corp.intel.com> <2902184.3RBbl2PCEx@thomas> <20200805164504.GE1716@bricha3-MOBL.ger.corp.intel.com> From: Ferruh Yigit Autocrypt: addr=ferruh.yigit@intel.com; prefer-encrypt=mutual; keydata= mQINBFXZCFABEADCujshBOAaqPZpwShdkzkyGpJ15lmxiSr3jVMqOtQS/sB3FYLT0/d3+bvy qbL9YnlbPyRvZfnP3pXiKwkRoR1RJwEo2BOf6hxdzTmLRtGtwWzI9MwrUPj6n/ldiD58VAGQ +iR1I/z9UBUN/ZMksElA2D7Jgg7vZ78iKwNnd+vLBD6I61kVrZ45Vjo3r+pPOByUBXOUlxp9 GWEKKIrJ4eogqkVNSixN16VYK7xR+5OUkBYUO+sE6etSxCr7BahMPKxH+XPlZZjKrxciaWQb +dElz3Ab4Opl+ZT/bK2huX+W+NJBEBVzjTkhjSTjcyRdxvS1gwWRuXqAml/sh+KQjPV1PPHF YK5LcqLkle+OKTCa82OvUb7cr+ALxATIZXQkgmn+zFT8UzSS3aiBBohg3BtbTIWy51jNlYdy ezUZ4UxKSsFuUTPt+JjHQBvF7WKbmNGS3fCid5Iag4tWOfZoqiCNzxApkVugltxoc6rG2TyX CmI2rP0mQ0GOsGXA3+3c1MCdQFzdIn/5tLBZyKy4F54UFo35eOX8/g7OaE+xrgY/4bZjpxC1 1pd66AAtKb3aNXpHvIfkVV6NYloo52H+FUE5ZDPNCGD0/btFGPWmWRmkPybzColTy7fmPaGz cBcEEqHK4T0aY4UJmE7Ylvg255Kz7s6wGZe6IR3N0cKNv++O7QARAQABtCVGZXJydWggWWln aXQgPGZlcnJ1aC55aWdpdEBpbnRlbC5jb20+iQJsBBMBCgBWAhsDAh4BAheABQsJCAcDBRUK CQgLBRYCAwEABQkKqZZ8FiEE0jZTh0IuwoTjmYHH+TPrQ98TYR8FAl6ha3sXGHZrczovL2tl eXMub3BlbnBncC5vcmcACgkQ+TPrQ98TYR8uLA//QwltuFliUWe60xwmu9sY38c1DXvX67wk UryQ1WijVdIoj4H8cf/s2KtyIBjc89R254KMEfJDao/LrXqJ69KyGKXFhFPlF3VmFLsN4XiT PSfxkx8s6kHVaB3O183p4xAqnnl/ql8nJ5ph9HuwdL8CyO5/7dC/MjZ/mc4NGq5O9zk3YRGO lvdZAp5HW9VKW4iynvy7rl3tKyEqaAE62MbGyfJDH3C/nV/4+mPc8Av5rRH2hV+DBQourwuC ci6noiDP6GCNQqTh1FHYvXaN4GPMHD9DX6LtT8Fc5mL/V9i9kEVikPohlI0WJqhE+vQHFzR2 1q5nznE+pweYsBi3LXIMYpmha9oJh03dJOdKAEhkfBr6n8BWkWQMMiwfdzg20JX0o7a/iF8H 4dshBs+dXdIKzPfJhMjHxLDFNPNH8zRQkB02JceY9ESEah3wAbzTwz+e/9qQ5OyDTQjKkVOo cxC2U7CqeNt0JZi0tmuzIWrfxjAUulVhBmnceqyMOzGpSCQIkvalb6+eXsC9V1DZ4zsHZ2Mx Hi+7pCksdraXUhKdg5bOVCt8XFmx1MX4AoV3GWy6mZ4eMMvJN2hjXcrreQgG25BdCdcxKgqp e9cMbCtF+RZax8U6LkAWueJJ1QXrav1Jk5SnG8/5xANQoBQKGz+yFiWcgEs9Tpxth15o2v59 gXK5Ag0EV9ZMvgEQAKc0Db17xNqtSwEvmfp4tkddwW9XA0tWWKtY4KUdd/jijYqc3fDD54ES YpV8QWj0xK4YM0dLxnDU2IYxjEshSB1TqAatVWz9WtBYvzalsyTqMKP3w34FciuL7orXP4Ai bPtrHuIXWQOBECcVZTTOdZYGAzaYzxiAONzF9eTiwIqe9/oaOjTwTLnOarHt16QApTYQSnxD UQljeNvKYt1lZE/gAUUxNLWsYyTT+22/vU0GDUahsJxs1+f1yEr+OGrFiEAmqrzpF0lCS3f/ 3HVTU6rS9cK3glVUeaTF4+1SK5ZNO35piVQCwphmxa+dwTG/DvvHYCtgOZorTJ+OHfvCnSVj sM4kcXGjJPy3JZmUtyL9UxEbYlrffGPQI3gLXIGD5AN5XdAXFCjjaID/KR1c9RHd7Oaw0Pdc q9UtMLgM1vdX8RlDuMGPrj5sQrRVbgYHfVU/TQCk1C9KhzOwg4Ap2T3tE1umY/DqrXQgsgH7 1PXFucVjOyHMYXXugLT8YQ0gcBPHy9mZqw5mgOI5lCl6d4uCcUT0l/OEtPG/rA1lxz8ctdFB VOQOxCvwRG2QCgcJ/UTn5vlivul+cThi6ERPvjqjblLncQtRg8izj2qgmwQkvfj+h7Ex88bI 8iWtu5+I3K3LmNz/UxHBSWEmUnkg4fJlRr7oItHsZ0ia6wWQ8lQnABEBAAGJAjwEGAEKACYC GwwWIQTSNlOHQi7ChOOZgcf5M+tD3xNhHwUCXqFrngUJCKxSYAAKCRD5M+tD3xNhH3YWD/9b cUiWaHJasX+OpiuZ1Li5GG3m9aw4lR/k2lET0UPRer2Jy1JsL+uqzdkxGvPqzFTBXgx/6Byz EMa2mt6R9BCyR286s3lxVS5Bgr5JGB3EkpPcoJT3A7QOYMV95jBiiJTy78Qdzi5LrIu4tW6H o0MWUjpjdbR01cnj6EagKrDx9kAsqQTfvz4ff5JIFyKSKEHQMaz1YGHyCWhsTwqONhs0G7V2 0taQS1bGiaWND0dIBJ/u0pU998XZhmMzn765H+/MqXsyDXwoHv1rcaX/kcZIcN3sLUVcbdxA WHXOktGTQemQfEpCNuf2jeeJlp8sHmAQmV3dLS1R49h0q7hH4qOPEIvXjQebJGs5W7s2vxbA 5u5nLujmMkkfg1XHsds0u7Zdp2n200VC4GQf8vsUp6CSMgjedHeF9zKv1W4lYXpHp576ZV7T GgsEsvveAE1xvHnpV9d7ZehPuZfYlP4qgo2iutA1c0AXZLn5LPcDBgZ+KQZTzm05RU1gkx7n gL9CdTzVrYFy7Y5R+TrE9HFUnsaXaGsJwOB/emByGPQEKrupz8CZFi9pkqPuAPwjN6Wonokv ChAewHXPUadcJmCTj78Oeg9uXR6yjpxyFjx3vdijQIYgi5TEGpeTQBymLANOYxYWYOjXk+ae dYuOYKR9nbPv+2zK9pwwQ2NXbUBystaGyQ== Message-ID: <27d08eb2-5f66-e385-3d05-39ac317ece89@intel.com> Date: Thu, 6 Aug 2020 22:41:23 +0100 MIME-Version: 1.0 In-Reply-To: <20200805164504.GE1716@bricha3-MOBL.ger.corp.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit 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" 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