From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from forward2m.mail.yandex.net ([37.140.138.2]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YTFeb-0007d0-Sg for barebox@lists.infradead.org; Wed, 04 Mar 2015 20:12:28 +0000 Received: from smtp3m.mail.yandex.net (smtp3m.mail.yandex.net [77.88.61.130]) by forward2m.mail.yandex.net (Yandex) with ESMTP id 062895CA0348 for ; Wed, 4 Mar 2015 23:12:01 +0300 (MSK) From: Andrey Panov Date: Wed, 4 Mar 2015 23:11:29 +0300 Message-Id: <1425499906-32125-2-git-send-email-rockford@yandex.ru> In-Reply-To: <1425499906-32125-1-git-send-email-rockford@yandex.ru> References: <1425499906-32125-1-git-send-email-rockford@yandex.ru> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH v2 01/18] lib: Add gcd() function To: barebox@lists.infradead.org It calculates greatest common divisor. Signed-off-by: Andrey Panov --- include/linux/gcd.h | 8 ++++++++ include/linux/kernel.h | 5 +++++ lib/Makefile | 1 + lib/gcd.c | 18 ++++++++++++++++++ 4 files changed, 32 insertions(+) create mode 100644 include/linux/gcd.h create mode 100644 lib/gcd.c diff --git a/include/linux/gcd.h b/include/linux/gcd.h new file mode 100644 index 0000000..0ac2621 --- /dev/null +++ b/include/linux/gcd.h @@ -0,0 +1,8 @@ +#ifndef _GCD_H +#define _GCD_H + +#include + +unsigned long gcd(unsigned long a, unsigned long b) __attribute_const__; + +#endif /* _GCD_H */ diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 3f2644c..5b6b448 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -257,5 +257,10 @@ static inline char *hex_byte_pack_upper(char *buf, u8 byte) const typeof( ((type *)0)->member ) *__mptr = (ptr); \ (type *)( (char *)__mptr - offsetof(type,member) );}) +/* + * swap - swap value of @a and @b + */ +#define swap(a, b) \ + do { typeof(a) __tmp = (a); (a) = (b); (b) = __tmp; } while (0) #endif /* _LINUX_KERNEL_H */ diff --git a/lib/Makefile b/lib/Makefile index b97e52d..f08ac59 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -52,3 +52,4 @@ obj-$(CONFIG_STMP_DEVICE) += stmp-device.o obj-y += wchar.o obj-y += libfile.o obj-y += bitmap.o +obj-y += gcd.o diff --git a/lib/gcd.c b/lib/gcd.c new file mode 100644 index 0000000..86bdba9 --- /dev/null +++ b/lib/gcd.c @@ -0,0 +1,18 @@ +#include + +/* Greatest common divisor */ +unsigned long gcd(unsigned long a, unsigned long b) +{ + unsigned long r; + + if (a < b) + swap(a, b); + + if (!b) + return a; + while ((r = a % b) != 0) { + a = b; + b = r; + } + return b; +} -- 2.1.4 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox