From mboxrd@z Thu Jan 1 00:00:00 1970 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 0055DEB64D9 for ; Wed, 14 Jun 2023 09:45:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243903AbjFNJok (ORCPT ); Wed, 14 Jun 2023 05:44:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235980AbjFNJoQ (ORCPT ); Wed, 14 Jun 2023 05:44:16 -0400 Received: from relay3-d.mail.gandi.net (relay3-d.mail.gandi.net [IPv6:2001:4b98:dc4:8::223]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E11E349C8; Wed, 14 Jun 2023 02:42:19 -0700 (PDT) X-GND-Sasl: herve.codina@bootlin.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1686735738; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+REmpcLHUL4BTOxA1dlLHsmBL+e+FBYJaTaqB02G6NY=; b=d+AXI1g8Y06cHn5FQ9HHfYpUkbPNIKBON81J0yuXI5c9++a6TK2xsCzbdQ8XJXKjFG0Ks2 IlS6uGDcORffGChF4976ahuklePO8PU76h62Q9MZtlVuydhY/lUSXXJIrMvanEK0VvcCIS K7bdwjIGwjy/ZcYCKTMQSyJLmycpDiEgwWvrzcoPoEtqVH0QyxVrTlSD0rpZ2JL8KtuiqD wqEZQiJlji6q9zYJBnNnorhUyaGiJcnkwZA375KbgVR26OSg2D0hrHNBQUHCzhd55ZePmM OTYg0eqK2ss1oCOt/DkCC2gsZZALpLj+rNIViYo2eFFQrNDSZtshDR9MMEM/EA== X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com X-GND-Sasl: herve.codina@bootlin.com Received: by mail.gandi.net (Postfix) with ESMTPSA id 6813C60004; Wed, 14 Jun 2023 09:42:15 +0000 (UTC) Date: Wed, 14 Jun 2023 11:42:14 +0200 From: Herve Codina To: Andy Shevchenko Cc: Liam Girdwood , Mark Brown , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jonathan Cameron , Lars-Peter Clausen , Jaroslav Kysela , Takashi Iwai , Kuninori Morimoto , alsa-devel@alsa-project.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, Christophe Leroy , Thomas Petazzoni Subject: Re: [PATCH v4 07/13] minmax: Introduce {min,max}_array() Message-ID: <20230614114214.1371485e@bootlin.com> In-Reply-To: References: <20230614074904.29085-1-herve.codina@bootlin.com> <20230614074904.29085-8-herve.codina@bootlin.com> Organization: Bootlin X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Andy, On Wed, 14 Jun 2023 12:02:57 +0300 Andy Shevchenko wrote: > On Wed, Jun 14, 2023 at 10:49 AM Herve Codina wrote: > > > > Introduce min_array() (resp max_array()) in order to get the > > minimal (resp maximum) of values present in an array. > > Reviewed-by: Andy Shevchenko > See a remark below. > > > Signed-off-by: Herve Codina > > --- > > include/linux/minmax.h | 36 ++++++++++++++++++++++++++++++++++++ > > 1 file changed, 36 insertions(+) > > > > diff --git a/include/linux/minmax.h b/include/linux/minmax.h > > index 396df1121bff..2cd0d34ce921 100644 > > --- a/include/linux/minmax.h > > +++ b/include/linux/minmax.h > > @@ -133,6 +133,42 @@ > > */ > > #define max_t(type, x, y) __careful_cmp((type)(x), (type)(y), >) > > > > +/* > > + * Do not check the array parameter using __must_be_array(). > > + * In the following legit use-case where the "array" passed is a simple pointer, > > + * __must_be_array() will return a failure. > > + * --- 8< --- > > + * int *buff > > + * ... > > + * min = min_array(buff, nb_items); > > + * --- 8< --- > > + */ > > +#define __minmax_array(op, array, len) ({ \ > > + typeof(array) __array = (array); \ > > + typeof(len) __len = (len); \ > > + typeof(__array[0] + 0) __element = __array[--__len]; \ > > Do we need the ' + 0' part? Yes. __array can be an array of const items and it is legitimate to get the minimum value from const items. typeof(__array[0]) keeps the const qualifier but we need to assign __element in the loop. One way to drop the const qualifier is to get the type from a rvalue computed from __array[0]. This rvalue has to have the exact same type with only the const dropped. '__array[0] + 0' was a perfect canditate. Regards, Hervé > > > + while (__len--) \ > > + __element = op(__element, __array[__len]); \ > > + __element; }) > > + > > +/** > > + * min_array - return minimum of values present in an array > > + * @array: array > > + * @len: array length > > + * > > + * Note that @len must not be zero (empty array). > > + */ > > +#define min_array(array, len) __minmax_array(min, array, len) > > + > > +/** > > + * max_array - return maximum of values present in an array > > + * @array: array > > + * @len: array length > > + * > > + * Note that @len must not be zero (empty array). > > + */ > > +#define max_array(array, len) __minmax_array(max, array, len) > > + > > /** > > * clamp_t - return a value clamped to a given range using a given type > > * @type: the type of variable to use > > -- > > 2.40.1 > > > >