From nobody Thu Dec 18 08:29:44 2025 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 CB9683F9EC for ; Sun, 28 Jul 2024 14:18:24 +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=1722176307; cv=none; b=YdLE8GQqpLquURMtqj+VmttdkvMp5+5WfBW/M7/JPK1UuRdQv+ARpAIjOYOCmb5VjkJkxpU9IHdED9nxREcPoFPlF2r8gGiTtoUZQh9ybqDQCv6Xp6S7R4enoJgMwup60CoOTVu60/A/eJ96kMG/Kg32tJzPh3rOu0ETkH8q4d8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722176307; c=relaxed/simple; bh=E8+TeBARjX1dBlV0YiDV6t+Yt+NzsvpygUkkzqnB8WA=; h=From:To:CC:Subject:Date:Message-ID:References:In-Reply-To: MIME-Version:Content-Type; b=KmmX7xFhlD9Xlr0yviSHUOHBsyktKIVJFNqtaCLrTLYNQ2vJ4SO1Akj5V/SKSKez37GJKZ914sWiHo8XjPo1UeTzzNaPu5ii6uBVnK/hkO2qJ8sM3mNP7IYrQq2q77SG0Z8T/Pk09gGx9yCL5SZTPRrC27k8wQ/ER0jW2oL3TfU= 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-68-U7LTviH9N2qGDn-NaZVzAQ-1; Sun, 28 Jul 2024 15:18:20 +0100 X-MC-Unique: U7LTviH9N2qGDn-NaZVzAQ-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, 28 Jul 2024 15:17:36 +0100 Received: from AcuMS.Aculab.com ([::1]) by AcuMS.aculab.com ([::1]) with mapi id 15.00.1497.048; Sun, 28 Jul 2024 15:17:36 +0100 From: David Laight To: "'linux-kernel@vger.kernel.org'" CC: 'Linus Torvalds' , 'Jens Axboe' , "'Matthew Wilcox (Oracle)'" , 'Christoph Hellwig' , 'Andrew Morton' , 'Andy Shevchenko' , 'Dan Carpenter' , 'Arnd Bergmann' , "'Jason@zx2c4.com'" , "'pedro.falcato@gmail.com'" , 'Mateusz Guzik' , "'linux-mm@kvack.org'" , 'Lorenzo Stoakes' Subject: [PATCH v2 1/8] minmax: Put all the clamp() definitions together Thread-Topic: [PATCH v2 1/8] minmax: Put all the clamp() definitions together Thread-Index: Adrg+PsJWBOjJVDsQ/+qaYGHKHGutQ== Date: Sun, 28 Jul 2024 14:17:35 +0000 Message-ID: <5cd3e11780df40b0b771da5548966ebd@AcuMS.aculab.com> References: <402c3c617c29465c898b1af55e3c6095@AcuMS.aculab.com> In-Reply-To: <402c3c617c29465c898b1af55e3c6095@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-kernel@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 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The defines for clamp() have got separated, move togther for readability. Update description of signedness check. Signed-off-by: David Laight --- v2: - No change. include/linux/minmax.h | 120 +++++++++++++++++++---------------------- 1 file changed, 56 insertions(+), 64 deletions(-) diff --git a/include/linux/minmax.h b/include/linux/minmax.h index a7ef65f78933..cea63a8ac80f 100644 --- a/include/linux/minmax.h +++ b/include/linux/minmax.h @@ -57,26 +57,6 @@ __cmp(op, x, y), \ __cmp_once(op, x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y))) =20 -#define __clamp(val, lo, hi) \ - ((val) >=3D (hi) ? (hi) : ((val) <=3D (lo) ? (lo) : (val))) - -#define __clamp_once(val, lo, hi, unique_val, unique_lo, unique_hi) ({ \ - typeof(val) unique_val =3D (val); \ - typeof(lo) unique_lo =3D (lo); \ - typeof(hi) unique_hi =3D (hi); \ - static_assert(__builtin_choose_expr(__is_constexpr((lo) > (hi)), \ - (lo) <=3D (hi), true), \ - "clamp() low limit " #lo " greater than high limit " #hi); \ - static_assert(__types_ok(val, lo), "clamp() 'lo' signedness error"); \ - static_assert(__types_ok(val, hi), "clamp() 'hi' signedness error"); \ - __clamp(unique_val, unique_lo, unique_hi); }) - -#define __careful_clamp(val, lo, hi) ({ \ - __builtin_choose_expr(__is_constexpr((val) - (lo) + (hi)), \ - __clamp(val, lo, hi), \ - __clamp_once(val, lo, hi, __UNIQUE_ID(__val), \ - __UNIQUE_ID(__lo), __UNIQUE_ID(__hi))); }) - /** * min - return minimum of two values of the same or compatible types * @x: first value @@ -124,6 +104,22 @@ */ #define max3(x, y, z) max((typeof(x))max(x, y), z) =20 +/** + * min_t - return minimum of two values, using the specified type + * @type: data type to use + * @x: first value + * @y: second value + */ +#define min_t(type, x, y) __careful_cmp(min, (type)(x), (type)(y)) + +/** + * max_t - return maximum of two values, using the specified type + * @type: data type to use + * @x: first value + * @y: second value + */ +#define max_t(type, x, y) __careful_cmp(max, (type)(x), (type)(y)) + /** * min_not_zero - return the minimum that is _not_ zero, unless both are z= ero * @x: value1 @@ -134,39 +130,60 @@ typeof(y) __y =3D (y); \ __x =3D=3D 0 ? __y : ((__y =3D=3D 0) ? __x : min(__x, __y)); }) =20 +#define __clamp(val, lo, hi) \ + ((val) >=3D (hi) ? (hi) : ((val) <=3D (lo) ? (lo) : (val))) + +#define __clamp_once(val, lo, hi, unique_val, unique_lo, unique_hi) ({ \ + typeof(val) unique_val =3D (val); \ + typeof(lo) unique_lo =3D (lo); \ + typeof(hi) unique_hi =3D (hi); \ + static_assert(__builtin_choose_expr(__is_constexpr((lo) > (hi)), \ + (lo) <=3D (hi), true), \ + "clamp() low limit " #lo " greater than high limit " #hi); \ + static_assert(__types_ok(val, lo), "clamp() 'lo' signedness error"); \ + static_assert(__types_ok(val, hi), "clamp() 'hi' signedness error"); \ + __clamp(unique_val, unique_lo, unique_hi); }) + +#define __careful_clamp(val, lo, hi) ({ \ + __builtin_choose_expr(__is_constexpr((val) - (lo) + (hi)), \ + __clamp(val, lo, hi), \ + __clamp_once(val, lo, hi, __UNIQUE_ID(__val), \ + __UNIQUE_ID(__lo), __UNIQUE_ID(__hi))); }) + /** * clamp - return a value clamped to a given range with strict typechecking * @val: current value * @lo: lowest allowable value * @hi: highest allowable value * - * This macro does strict typechecking of @lo/@hi to make sure they are of= the - * same type as @val. See the unnecessary pointer comparisons. + * This macro checks that @val, @lo and @hi have the same signedness. */ #define clamp(val, lo, hi) __careful_clamp(val, lo, hi) =20 -/* - * ..and if you can't take the strict - * types, you can specify one yourself. - * - * Or not use min/max/clamp at all, of course. - */ - /** - * min_t - return minimum of two values, using the specified type - * @type: data type to use - * @x: first value - * @y: second value + * clamp_t - return a value clamped to a given range using a given type + * @type: the type of variable to use + * @val: current value + * @lo: minimum allowable value + * @hi: maximum allowable value + * + * This macro does no typechecking and uses temporary variables of type + * @type to make all the comparisons. */ -#define min_t(type, x, y) __careful_cmp(min, (type)(x), (type)(y)) +#define clamp_t(type, val, lo, hi) __careful_clamp((type)(val), (type)(lo)= , (type)(hi)) =20 /** - * max_t - return maximum of two values, using the specified type - * @type: data type to use - * @x: first value - * @y: second value + * clamp_val - return a value clamped to a given range using val's type + * @val: current value + * @lo: minimum allowable value + * @hi: maximum allowable value + * + * This macro does no typechecking and uses temporary variables of whatever + * type the input argument @val is. This is useful when @val is an unsign= ed + * type and @lo and @hi are literals that will otherwise be assigned a sig= ned + * integer type. */ -#define max_t(type, x, y) __careful_cmp(max, (type)(x), (type)(y)) +#define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi) =20 /* * Do not check the array parameter using __must_be_array(). @@ -211,31 +228,6 @@ */ #define max_array(array, len) __minmax_array(max, array, len) =20 -/** - * clamp_t - return a value clamped to a given range using a given type - * @type: the type of variable to use - * @val: current value - * @lo: minimum allowable value - * @hi: maximum allowable value - * - * This macro does no typechecking and uses temporary variables of type - * @type to make all the comparisons. - */ -#define clamp_t(type, val, lo, hi) __careful_clamp((type)(val), (type)(lo)= , (type)(hi)) - -/** - * clamp_val - return a value clamped to a given range using val's type - * @val: current value - * @lo: minimum allowable value - * @hi: maximum allowable value - * - * This macro does no typechecking and uses temporary variables of whatever - * type the input argument @val is. This is useful when @val is an unsign= ed - * type and @lo and @hi are literals that will otherwise be assigned a sig= ned - * integer type. - */ -#define clamp_val(val, lo, hi) clamp_t(typeof(val), val, lo, hi) - static inline bool in_range64(u64 val, u64 start, u64 len) { return (val - start) < len; --=20 2.17.1 - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1= PT, UK Registration No: 1397386 (Wales)