From patchwork Sun Feb 25 16:46:20 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Laight X-Patchwork-Id: 13570949 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.85.151]) (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 14E8A134A5 for ; Sun, 25 Feb 2024 16:46:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.58.85.151 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708879588; cv=none; b=N5fea1/E8dWmhUf/fXhPT+lZGJ7Y5TDh2suXxD9IezVZ2s9JJQIEPAmoP3bvfmg2euVIjj3mqMyPKoEOyWZ+1hV6nwyLY4r8RNv+Rv541rABtV+WkbZ1gabCLIj7NBb9SdiZAV01EIqAYY3gYnbMO+ljhvzOP/5qP7NZ0DQirZU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708879588; c=relaxed/simple; bh=vFwDF1W1RkazrGXsBXcrCyhzRqXEEq2KkvvTlcmlZCA=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=UC+qFmUbpIfB9xN2AB8X3GKWwfsdj4wB3r7mV7sBl6vU5uD5Noe6yTEl+ROwG5jNdEBbE9e+Jq+t2c+XR8U2m5jnnpPtsfM5IeAdYic9f9U18Y9jX6RkzDjgqaZ4ZwJ2gWaaaNImpaQSDwgiv3GNTrXyJTC4HbUG4137cJfI/Ok= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ACULAB.COM; spf=pass smtp.mailfrom=aculab.com; arc=none smtp.client-ip=185.58.85.151 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ACULAB.COM Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=aculab.com Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with both STARTTLS and AUTH (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-178-yjK-uS7gN62oNJ6hHLWGlQ-1; Sun, 25 Feb 2024 16:46:21 +0000 X-MC-Unique: yjK-uS7gN62oNJ6hHLWGlQ-1 Received: from AcuMS.Aculab.com (10.202.163.6) by AcuMS.aculab.com (10.202.163.6) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Sun, 25 Feb 2024 16:46:20 +0000 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Sun, 25 Feb 2024 16:46:20 +0000 From: David Laight To: "'linux-kernel@vger.kernel.org'" , "'Linus Torvalds'" , 'Netdev' , "'dri-devel@lists.freedesktop.org'" CC: 'Jens Axboe' , "'Matthew Wilcox (Oracle)'" , 'Christoph Hellwig' , "'linux-btrfs@vger.kernel.org'" , "'Andrew Morton'" , 'Andy Shevchenko' , "'David S . Miller'" , 'Dan Carpenter' , "'Jani Nikula'" Subject: [PATCH next v2 00/11] minmax: Optimise to reduce .i line length Thread-Topic: [PATCH next v2 00/11] minmax: Optimise to reduce .i line length Thread-Index: AdpoChcPZRn+4DJyQnmPt8VEo0gk8Q== Date: Sun, 25 Feb 2024 16:46:20 +0000 Message-ID: <0fff52305e584036a777f440b5f474da@AcuMS.aculab.com> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US The changes to minmax.h that changed the type check to a signedness check significantly increased the length of the expansion. In some cases it has also significantly increased compile type. This is particularly noticable for nested expansions. The fact that _Static_assert() only requires a compile time constant not a constant expression allows a lot of simplification. The other thing that compilicates the expansion is the necessity of returning a constant expression from constant arguments (for VLA). I can only find a handful of places this is done. Penalising most of the code for these few cases seems 'suboptimal'. Instead I've added min_const() and max_const() for VLA and static initialisers, these check the arguments are constant to avoid misuse. Patch [9] is dependant on the earlier patches. Patch [10] isn't dependant on them. Patch [11] depends on both 9 and 10. Changes for v2: - Typographical and spelling corrections to the commit messages. Patches unchanged. David Laight (11): [1] minmax: Put all the clamp() definitions together [2] minmax: Use _Static_assert() instead of static_assert() [3] minmax: Simplify signedness check [4] minmax: Replace multiple __UNIQUE_ID() by directly using __COUNTER__ [5] minmax: Move the signedness check out of __cmp_once() and __clamp_once() [6] minmax: Remove 'constexpr' check from __careful_clamp() [7] minmax: minmax: Add __types_ok3() and optimise defines with 3 arguments [8] minmax: Add min_const() and max_const() [9] tree-wide: minmax: Replace all the uses of max() for array sizes with max_const(). [10] block: Use a boolean expression instead of max() on booleans [11] minmax: min() and max() don't need to return constant expressions block/blk-settings.c | 2 +- drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c | 2 +- drivers/gpu/drm/drm_color_mgmt.c | 4 +- drivers/input/touchscreen/cyttsp4_core.c | 2 +- .../net/can/usb/etas_es58x/es58x_devlink.c | 2 +- fs/btrfs/tree-checker.c | 2 +- include/linux/minmax.h | 211 ++++++++++-------- lib/vsprintf.c | 4 +- net/ipv4/proc.c | 2 +- net/ipv6/proc.c | 2 +- 10 files changed, 127 insertions(+), 106 deletions(-)