[PATCH 1/8] add lib/gcd.c

Florian Fainelli
2009-06-04T14:15:24Z

This patch adds lib/gcd.c which contains a greatest
common divider implementation taken from
sound/core/pcm_timer.c

Signed-off-by: Florian Fainelli <florian@openwrt.org>
---
diff --git a/include/linux/gcd.h b/include/linux/gcd.h
new file mode 100644
index 0000000..69f5e8a
--- /dev/null
+++ b/include/linux/gcd.h
@@ -0,0 +1,8 @@
+#ifndef _GCD_H
+#define _GCD_H
+
+#include <linux/compiler.h>
+
+unsigned long gcd(unsigned long a, unsigned long b) __attribute_const__;
+
+#endif /* _GCD_H */
diff --git a/lib/Kconfig b/lib/Kconfig
index 8ade0a7..70a9906 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -10,6 +10,9 @@ menu "Library routines"
config BITREVERSE
tristate

+config GCD
+ bool
+
config GENERIC_FIND_FIRST_BIT
bool

diff --git a/lib/Makefile b/lib/Makefile
index 33a40e4..389bdd2 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -57,6 +57,7 @@ obj-$(CONFIG_CRC_ITU_T) += crc-itu-t.o
obj-$(CONFIG_CRC32) += crc32.o
obj-$(CONFIG_CRC7) += crc7.o
obj-$(CONFIG_LIBCRC32C) += libcrc32c.o
+obj-$(CONFIG_GCD) += gcd.o
obj-$(CONFIG_GENERIC_ALLOCATOR) += genalloc.o

obj-$(CONFIG_ZLIB_INFLATE) += zlib_inflate/
diff --git a/lib/gcd.c b/lib/gcd.c
new file mode 100644
index 0000000..fbf81a8
--- /dev/null
+++ b/lib/gcd.c
@@ -0,0 +1,20 @@
+#include <linux/gcd.h>
+#include <linux/module.h>
+
+/* Greatest common divisor */
+unsigned long gcd(unsigned long a, unsigned long b)
+{
+ unsigned long r;
+
+ if (a < b) {
+ r = a;
+ a = b;
+ b = r;
+ }
+ while ((r = a % b) != 0) {
+ a = b;
+ b = r;
+ }
+ return b;
+}
+EXPORT_SYMBOL(gcd);