Commit d2829224 authored by Florian Fainelli's avatar Florian Fainelli Committed by Linus Torvalds

lib: add lib/gcd.c

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

Several usages of this new library function will be sent to subsystem
maintainers.

[akpm@linux-foundation.org: use swap() (pointed out by Joe)]
[akpm@linux-foundation.org: just add gcd.o to obj-y, remove Kconfig changes]
Signed-off-by: default avatarFlorian Fainelli <florian@openwrt.org>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Simon Horman <horms@verge.net.au>
Cc: Julius Volz <juliusv@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent eae9d2ba
#ifndef _GCD_H
#define _GCD_H
#include <linux/compiler.h>
unsigned long gcd(unsigned long a, unsigned long b) __attribute_const__;
#endif /* _GCD_H */
......@@ -21,7 +21,7 @@ lib-y += kobject.o kref.o klist.o
obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \
string_helpers.o
string_helpers.o gcd.o
ifeq ($(CONFIG_DEBUG_KOBJECT),y)
CFLAGS_kobject.o += -DDEBUG
......
#include <linux/kernel.h>
#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)
swap(a, b);
while ((r = a % b) != 0) {
a = b;
b = r;
}
return b;
}
EXPORT_SYMBOL_GPL(gcd);
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