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bitops: use __fls for fls64 on 64-bit archs

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Use __fls for fls64 on 64-bit archs. The implementation for
64-bit archs is moved from x86_64 to asm-generic.

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Alexander van Heukelum 2008-03-15 18:32:36 +01:00 committed by Ingo Molnar
parent 56a6b1eb7b
commit d57594c203
2 changed files with 24 additions and 13 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

22
include/asm-generic/bitops/fls64.h
View file

@ -3,6 +3,18 @@
#include <asm/types.h> #include <asm/types.h>
/**
* fls64 - find last set bit in a 64-bit word
* @x: the word to search
*
* This is defined in a similar way as the libc and compiler builtin
* ffsll, but returns the position of the most significant set bit.
*
* fls64(value) returns 0 if value is 0 or the position of the last
* set bit if value is nonzero. The last (most significant) bit is
* at position 64.
*/
#if BITS_PER_LONG == 32
static inline int fls64(__u64 x) static inline int fls64(__u64 x)
{ {
__u32 h = x >> 32; __u32 h = x >> 32;
@ -10,5 +22,15 @@ static inline int fls64(__u64 x)
return fls(h) + 32; return fls(h) + 32;
return fls(x); return fls(x);
} }
#elif BITS_PER_LONG == 64
static inline int fls64(__u64 x)
{
if (x == 0)
return 0;
return __fls(x) + 1;
}
#else
#error BITS_PER_LONG not 32 or 64
#endif
#endif /* _ASM_GENERIC_BITOPS_FLS64_H_ */ #endif /* _ASM_GENERIC_BITOPS_FLS64_H_ */

15
include/asm-x86/bitops_64.h
View file

@ -39,25 +39,14 @@ static inline void set_bit_string(unsigned long *bitmap, unsigned long i,
#include <asm-generic/bitops/sched.h> #include <asm-generic/bitops/sched.h>
/**
* fls64 - find last bit set in 64 bit word
* @x: the word to search
*
* This is defined the same way as fls.
*/
static inline int fls64(__u64 x)
{
if (x == 0)
return 0;
return __fls(x) + 1;
}
#define ARCH_HAS_FAST_MULTIPLIER 1 #define ARCH_HAS_FAST_MULTIPLIER 1
#include <asm-generic/bitops/hweight.h> #include <asm-generic/bitops/hweight.h>
#endif /* __KERNEL__ */ #endif /* __KERNEL__ */
#include <asm-generic/bitops/fls64.h>
#ifdef __KERNEL__ #ifdef __KERNEL__
#include <asm-generic/bitops/ext2-non-atomic.h> #include <asm-generic/bitops/ext2-non-atomic.h>