From nobody Thu Sep 11 16:47:09 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5C9DCD13DD for ; Mon, 18 Sep 2023 08:20:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240850AbjIRITl convert rfc822-to-8bit (ORCPT ); Mon, 18 Sep 2023 04:19:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44858 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240996AbjIRITG (ORCPT ); Mon, 18 Sep 2023 04:19:06 -0400 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.85.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C552412F for ; Mon, 18 Sep 2023 01:16:58 -0700 (PDT) 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-66-K0WpNAvKPb2jQwtICPCfbQ-1; Mon, 18 Sep 2023 09:16:41 +0100 X-MC-Unique: K0WpNAvKPb2jQwtICPCfbQ-1 Received: from AcuMS.Aculab.com (10.202.163.4) by AcuMS.aculab.com (10.202.163.4) with Microsoft SMTP Server (TLS) id 15.0.1497.48; Mon, 18 Sep 2023 09:16:30 +0100 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Mon, 18 Sep 2023 09:16:30 +0100 From: David Laight To: "linux-kernel@vger.kernel.org" CC: Linus Torvalds , 'Andy Shevchenko' , 'Andrew Morton' , "'Matthew Wilcox (Oracle)'" , 'Christoph Hellwig' , "'Jason A. Donenfeld'" Subject: [PATCH next v4 1/5] minmax: Add umin(a, b) and umax(a, b) Thread-Topic: [PATCH next v4 1/5] minmax: Add umin(a, b) and umax(a, b) Thread-Index: AdnqCG3fyWBHnOXsRX2exERoRDa2+g== Date: Mon, 18 Sep 2023 08:16:30 +0000 Message-ID: <41d93ca827a248698ec64bf57e0c05a5@AcuMS.aculab.com> References: In-Reply-To: Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" These can be used when min()/max() errors a signed v unsigned compare when the signed value is known to be non-negative. Unlike min_t(some_unsigned_type, a, b) umin() will never mask off high bits if an inappropriate type is selected. The '+ 0u + 0ul + 0ull' may look strange. The '+ 0u' is needed for 'signed int' on 64bit systems. The '+ 0ul' is needed for 'signed long' on 32bit systems. The '+ 0ull' is needed for 'signed long long'. Signed-off-by: David Laight -- v4: Rename (from min_unsigned) to shorten code lines. Suggested by Linus. v3: No change. v2: Updated commit message. --- include/linux/minmax.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/include/linux/minmax.h b/include/linux/minmax.h index 83aebc244cba..0e89c78810f6 100644 --- a/include/linux/minmax.h +++ b/include/linux/minmax.h @@ -74,6 +74,23 @@ */ #define max(x, y) __careful_cmp(x, y, >) =20 +/** + * umin - return minimum of two non-negative values + * Signed types are zero extended to match a larger unsigned type. + * @x: first value + * @y: second value + */ +#define umin(x, y) \ + __careful_cmp((x) + 0u + 0ul + 0ull, (y) + 0u + 0ul + 0ull, <) + +/** + * umax - return maximum of two non-negative values + * @x: first value + * @y: second value + */ +#define umax(x, y) \ + __careful_cmp((x) + 0u + 0ul + 0ull, (y) + 0u + 0ul + 0ull, >) + /** * min3 - return minimum of three values * @x: first value --=20 2.17.1 - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1= PT, UK Registration No: 1397386 (Wales)