From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id CF8E745B57; Thu, 17 Oct 2024 07:50:15 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 71C4E4021F; Thu, 17 Oct 2024 07:50:15 +0200 (CEST) Received: from mail.lysator.liu.se (mail.lysator.liu.se [130.236.254.3]) by mails.dpdk.org (Postfix) with ESMTP id 4983040144 for ; Thu, 17 Oct 2024 07:50:14 +0200 (CEST) Received: from mail.lysator.liu.se (localhost [127.0.0.1]) by mail.lysator.liu.se (Postfix) with ESMTP id 084BA1BB51 for ; Thu, 17 Oct 2024 07:50:14 +0200 (CEST) Received: by mail.lysator.liu.se (Postfix, from userid 1004) id F0DCB1BC35; Thu, 17 Oct 2024 07:50:13 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 4.0.0 (2022-12-13) on hermod.lysator.liu.se X-Spam-Level: X-Spam-Status: No, score=-1.2 required=5.0 tests=ALL_TRUSTED,AWL, T_SCC_BODY_TEXT_LINE autolearn=disabled version=4.0.0 X-Spam-Score: -1.2 Received: from [192.168.1.85] (h-62-63-215-114.A163.priv.bahnhof.se [62.63.215.114]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mail.lysator.liu.se (Postfix) with ESMTPSA id 9A4DA1BC84; Thu, 17 Oct 2024 07:50:06 +0200 (CEST) Message-ID: Date: Thu, 17 Oct 2024 07:50:06 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] devtools: forbid the use of ffs compiler builtins To: Stephen Hemminger , =?UTF-8?Q?Mattias_R=C3=B6nnblom?= Cc: dev@dpdk.org, David Marchand References: <20241016135411.827850-1-mattias.ronnblom@ericsson.com> <20241016135411.827850-2-mattias.ronnblom@ericsson.com> <20241016080424.3f614ac2@hermes.local> Content-Language: en-US From: =?UTF-8?Q?Mattias_R=C3=B6nnblom?= In-Reply-To: <20241016080424.3f614ac2@hermes.local> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Virus-Scanned: ClamAV using ClamSMTP X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org On 2024-10-16 17:04, Stephen Hemminger wrote: > On Wed, 16 Oct 2024 15:54:11 +0200 > Mattias Rönnblom wrote: > >> Extend checkpatches.sh to detect the use of __builtin_(ffs|ffsll). >> >> These intrinsics are not available in MSVC, and there are perfectly >> serviceable alternatives in . >> >> Signed-off-by: Mattias Rönnblom >> Suggested-by: David Marchand > > Shouldn't this apply to all _builtin_ functions. > Aren̈́'t GCC builtins pretty much standard? So any driver not targeting Windows should be fine, although it would be better to use a DPDK wrapper. > There are a lot of drivers still doing this. I would suggest we fix this when someone has taken the time to improve/modernize/extend further (e.g., with _Generic versions of all bit fiddling and count functions and "all" __builtins are covered). I guess other APIs also may need to be extended (for non-bitops builtins).