diff options
Diffstat (limited to 'fs/xfs/xfs_bit.h')
| -rw-r--r-- | fs/xfs/xfs_bit.h | 29 |
1 files changed, 16 insertions, 13 deletions
diff --git a/fs/xfs/xfs_bit.h b/fs/xfs/xfs_bit.h index 325a007dec9..e1649c0d3e0 100644 --- a/fs/xfs/xfs_bit.h +++ b/fs/xfs/xfs_bit.h @@ -23,24 +23,16 @@ */ /* - * masks with n high/low bits set, 32-bit values & 64-bit values + * masks with n high/low bits set, 64-bit values */ -#define XFS_MASK32HI(n) xfs_mask32hi(n) -static inline __uint32_t xfs_mask32hi(int n) -{ - return (__uint32_t)-1 << (32 - (n)); -} -#define XFS_MASK64HI(n) xfs_mask64hi(n) static inline __uint64_t xfs_mask64hi(int n) { return (__uint64_t)-1 << (64 - (n)); } -#define XFS_MASK32LO(n) xfs_mask32lo(n) static inline __uint32_t xfs_mask32lo(int n) { return ((__uint32_t)1 << (n)) - 1; } -#define XFS_MASK64LO(n) xfs_mask64lo(n) static inline __uint64_t xfs_mask64lo(int n) { return ((__uint64_t)1 << (n)) - 1; @@ -61,15 +53,26 @@ static inline int xfs_highbit64(__uint64_t v) /* Get low bit set out of 32-bit argument, -1 if none set */ static inline int xfs_lowbit32(__uint32_t v) { - __uint32_t t = v; - return (t) ? find_first_bit((unsigned long *)&t, 32) : -1; + return ffs(v) - 1; } /* Get low bit set out of 64-bit argument, -1 if none set */ static inline int xfs_lowbit64(__uint64_t v) { - __uint64_t t = v; - return (t) ? find_first_bit((unsigned long *)&t, 64) : -1; + __uint32_t w = (__uint32_t)v; + int n = 0; + + if (w) { /* lower bits */ + n = ffs(w); + } else { /* upper bits */ + w = (__uint32_t)(v >> 32); + if (w) { + n = ffs(w); + if (n) + n += 32; + } + } + return n - 1; } /* Return whether bitmap is empty (1 == empty) */ |