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Diffstat (limited to 'arch/arm/include/asm/bitops.h')
-rw-r--r--arch/arm/include/asm/bitops.h16
1 files changed, 10 insertions, 6 deletions
diff --git a/arch/arm/include/asm/bitops.h b/arch/arm/include/asm/bitops.h
index 9a1db20e032a..63a481fbbed4 100644
--- a/arch/arm/include/asm/bitops.h
+++ b/arch/arm/include/asm/bitops.h
@@ -237,6 +237,7 @@ extern int _find_next_bit_be(const unsigned long *p, int size, int offset);
237#if __LINUX_ARM_ARCH__ < 5 237#if __LINUX_ARM_ARCH__ < 5
238 238
239#include <asm-generic/bitops/ffz.h> 239#include <asm-generic/bitops/ffz.h>
240#include <asm-generic/bitops/__fls.h>
240#include <asm-generic/bitops/__ffs.h> 241#include <asm-generic/bitops/__ffs.h>
241#include <asm-generic/bitops/fls.h> 242#include <asm-generic/bitops/fls.h>
242#include <asm-generic/bitops/ffs.h> 243#include <asm-generic/bitops/ffs.h>
@@ -277,16 +278,19 @@ static inline int constant_fls(int x)
277 * the clz instruction for much better code efficiency. 278 * the clz instruction for much better code efficiency.
278 */ 279 */
279 280
280#define __fls(x) \
281 ( __builtin_constant_p(x) ? constant_fls(x) : \
282 ({ int __r; asm("clz\t%0, %1" : "=r"(__r) : "r"(x) : "cc"); 32-__r; }) )
283
284/* Implement fls() in C so that 64-bit args are suitably truncated */
285static inline int fls(int x) 281static inline int fls(int x)
286{ 282{
287 return __fls(x); 283 int ret;
284
285 if (__builtin_constant_p(x))
286 return constant_fls(x);
287
288 asm("clz\t%0, %1" : "=r" (ret) : "r" (x) : "cc");
289 ret = 32 - ret;
290 return ret;
288} 291}
289 292
293#define __fls(x) (fls(x) - 1)
290#define ffs(x) ({ unsigned long __t = (x); fls(__t & -__t); }) 294#define ffs(x) ({ unsigned long __t = (x); fls(__t & -__t); })
291#define __ffs(x) (ffs(x) - 1) 295#define __ffs(x) (ffs(x) - 1)
292#define ffz(x) __ffs( ~(x) ) 296#define ffz(x) __ffs( ~(x) )