From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9EBF323BCEE for ; Tue, 2 Sep 2025 09:54:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756806878; cv=none; b=h3zvszNSKVk8Bbb10MJ/tv0E7SNC7+cAyXH8Y9uudhQ+zhRsVQ5t8i+/CumAutHjz7ZgK6L8vvfdAtvnG18ce/8nnybtppoJINs6fo34Wcc4jC5ij9C0bRSXLh66dJ9IXQ3l5X38PSbSLYsyftaGqN0Nb8Tg8Uc1DLLP6iIs/8A= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756806878; c=relaxed/simple; bh=mrWYcJsYgFEREkPfiWU5na3mwUt9On8OWsszpHczC6w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=rjQBUcVoBDwukurCENZEIO//dkMMUhPZnRr2G7DJsxbBrL2SANcA4i+lBB+kiXvgK7Mi7mHEYbAzKrZV/jkYiVbPiDJR3WpeICcuWHm/AgkjdjGeMJnE3Slkj82wr1Qn7wPKzU/G1U6DdGUGDLlzM47msZTsTwNFRK/qNOQ8Wkg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=OkPXHxox; arc=none smtp.client-ip=192.198.163.18 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="OkPXHxox" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1756806877; x=1788342877; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=mrWYcJsYgFEREkPfiWU5na3mwUt9On8OWsszpHczC6w=; b=OkPXHxoxtQXVWSpdzTPJb0XP2+Uc7BvaHnf2xyOuMNlcS6fJSKskLBi/ CSIMxeuYLyFL7QgH80cjLNep7vSZrxFW9i89lYwUAs+TtPwdmEJcqFIP+ 6V1st+DKHdlTjzc3a6sCLXGRBmGK9KANU3pG5m844+Q2ZCZCnGUVwlC7H d3N6VYO30dtHzlMSDk35Fpr4JPYVGkz85O2xbh6tuf9Bt0cTPLQ1MR338 /Pe5iLH48DGjDw3LdxL7RmSdLLoIZEOlbp8asI1y2g3PWOSVT7sb20b3z XKKNRm1Q3tWHaeu5r2I6NqQcekgglFeAFwg7DNf6+Y6VMM1OkGmdHMHYZ A==; X-CSE-ConnectionGUID: q8BwFAYaSgasQHv8kT6B0w== X-CSE-MsgGUID: 2kk8rgjYRF+Vb3qeS5ACCQ== X-IronPort-AV: E=McAfee;i="6800,10657,11540"; a="58277747" X-IronPort-AV: E=Sophos;i="6.18,230,1751266800"; d="scan'208";a="58277747" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by fmvoesa112.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Sep 2025 02:54:34 -0700 X-CSE-ConnectionGUID: aNRjji1wSgaKIaQvhq8ozA== X-CSE-MsgGUID: nE4xiCayQya9ygb9wMscpw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.18,230,1751266800"; d="scan'208";a="176507746" Received: from smile.fi.intel.com ([10.237.72.52]) by fmviesa004.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Sep 2025 02:54:31 -0700 Received: from andy by smile.fi.intel.com with local (Exim 4.98.2) (envelope-from ) id 1utNie-0000000AeyC-2MIl; Tue, 02 Sep 2025 12:54:28 +0300 Date: Tue, 2 Sep 2025 12:54:28 +0300 From: Andy Shevchenko To: Dan Carpenter Cc: Adrian =?utf-8?Q?Barna=C5=9B?= , Hans de Goede , Mauro Carvalho Chehab , Sakari Ailus , Andy Shevchenko , Greg Kroah-Hartman , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-staging@lists.linux.dev Subject: Re: [RFC] staging: media: atomisp: Simplyfy masking bit logic Message-ID: References: <20250902073841.2338568-1-abarnas@google.com> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo On Tue, Sep 02, 2025 at 12:02:29PM +0300, Dan Carpenter wrote: > On Tue, Sep 02, 2025 at 07:38:40AM +0000, Adrian Barnaś wrote: ... > > static inline hive_uedge > > inv_subword(hive_uedge w, unsigned int start, unsigned int end) > > { > > - return w & (~(((1ULL << (end - 1)) - 1) << 1 | 1) | ((1ULL << start) - 1)); > > + return w & (~__GENMASK_ULL(end-1, start)); > > } > > nit: white space. Add spaces. Remove parentheses. > > These are supposed to be opposites, right? Subword and inverse Subword. > You could dress them up to make them look more opposite. > > return (w & __GENMASK_ULL(end - 1, start)) >> start; > return w & ~__GENMASK_ULL(end - 1, start); The problem is (and actually with the (end-1, start) above that it might generate a really bad code on some CPUs, so I really, really prefer the way when _at least_ one of the parameters is constant. That said, using GENMASK_ULL(end - 1, 0) in both cases makes also them look more similar (and opposition comes on how start is being used). -- With Best Regards, Andy Shevchenko