lib: Add gcd() function

It calculates greatest common divisor.

Signed-off-by: Andrey Panov <rockford@yandex.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

2 files changed, 19 insertions, 0 deletions

diff --git a/lib/Makefile b/lib/Makefile
index 226570a7e6..1684649dd5 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -51,3 +51,4 @@ 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 0000000000..86bdba9112
--- /dev/null
+++ b/lib/gcd.c
@@ -0,0 +1,18 @@
+#include <linux/gcd.h>
+
+/* 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;
+}