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authorDavid Chinner <david@fromorbit.com>2008-08-13 15:41:12 +1000
committerLachlan McIlroy <lachlan@redback.melbourne.sgi.com>2008-08-13 15:41:12 +1000
commit79071eb0b2f142b9cc6531d04fa2915943938b5e (patch)
treedfab0f9e306322454f98c5ae77e93d1150aefbeb /fs/xfs/xfs_bit.h
parent10fec20ef5eec1c91913baec1225400f0d02df40 (diff)
[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 <david@fromorbit.com> Signed-off-by: Eric Sandeen <sandeen@sandeen.net> Signed-off-by: Donald Douwsma <donaldd@sgi.com> Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Diffstat (limited to 'fs/xfs/xfs_bit.h')
-rw-r--r--fs/xfs/xfs_bit.h34
1 files changed, 30 insertions, 4 deletions
diff --git a/fs/xfs/xfs_bit.h b/fs/xfs/xfs_bit.h
index 082641a9782..8e0e463dae2 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);