From 79071eb0b2f142b9cc6531d04fa2915943938b5e Mon Sep 17 00:00:00 2001 From: David Chinner Date: Wed, 13 Aug 2008 15:41:12 +1000 Subject: [XFS] Use the generic bitops rather than implementing them ourselves. This keeps xfs_lowbit64 as it was since there aren't good generic helpers there ... Patch inspired by Andi Kleen. SGI-PV: 981498 SGI-Modid: xfs-linux-melb:xfs-kern:31472a Signed-off-by: David Chinner Signed-off-by: Eric Sandeen Signed-off-by: Donald Douwsma Signed-off-by: Lachlan McIlroy --- fs/xfs/xfs_bit.h | 34 ++++++++++++++++++++++++++++++---- 1 file changed, 30 insertions(+), 4 deletions(-) (limited to 'fs/xfs/xfs_bit.h') diff --git a/fs/xfs/xfs_bit.h b/fs/xfs/xfs_bit.h index 082641a9782c..8e0e463dae2d 100644 --- a/fs/xfs/xfs_bit.h +++ b/fs/xfs/xfs_bit.h @@ -47,13 +47,39 @@ static inline __uint64_t xfs_mask64lo(int n) } /* Get high bit set out of 32-bit argument, -1 if none set */ -extern int xfs_highbit32(__uint32_t v); +static inline int xfs_highbit32(__uint32_t v) +{ + return fls(v) - 1; +} + +/* Get high bit set out of 64-bit argument, -1 if none set */ +static inline int xfs_highbit64(__uint64_t v) +{ + return fls64(v) - 1; +} + +/* Get low bit set out of 32-bit argument, -1 if none set */ +static inline int xfs_lowbit32(__uint32_t v) +{ + unsigned long t = v; + return (v) ? find_first_bit(&t, 32) : -1; +} /* Get low bit set out of 64-bit argument, -1 if none set */ -extern int xfs_lowbit64(__uint64_t v); +static inline int xfs_lowbit64(__uint64_t v) +{ + __uint32_t w = (__uint32_t)v; + int n = 0; -/* Get high bit set out of 64-bit argument, -1 if none set */ -extern int xfs_highbit64(__uint64_t); + if (w) { /* lower bits */ + n = ffs(w); + } else { /* upper bits */ + w = (__uint32_t)(v >> 32); + if (w && (n = ffs(w))) + n += 32; + } + return n - 1; +} /* Return whether bitmap is empty (1 == empty) */ extern int xfs_bitmap_empty(uint *map, uint size); -- cgit v1.2.3