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Diffstat (limited to 'fs/xfs/libxfs/xfs_bit.h')
-rw-r--r--fs/xfs/libxfs/xfs_bit.h87
1 files changed, 87 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_bit.h b/fs/xfs/libxfs/xfs_bit.h
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index 000000000000..e1649c0d3e02
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+++ b/fs/xfs/libxfs/xfs_bit.h
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+/*
+ * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#ifndef __XFS_BIT_H__
+#define __XFS_BIT_H__
+
+/*
+ * XFS bit manipulation routines.
+ */
+
+/*
+ * masks with n high/low bits set, 64-bit values
+ */
+static inline __uint64_t xfs_mask64hi(int n)
+{
+ return (__uint64_t)-1 << (64 - (n));
+}
+static inline __uint32_t xfs_mask32lo(int n)
+{
+ return ((__uint32_t)1 << (n)) - 1;
+}
+static inline __uint64_t xfs_mask64lo(int n)
+{
+ return ((__uint64_t)1 << (n)) - 1;
+}
+
+/* Get high bit set out of 32-bit argument, -1 if none set */
+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)
+{
+ 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)
+{
+ __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) */
+extern int xfs_bitmap_empty(uint *map, uint size);
+
+/* Count continuous one bits in map starting with start_bit */
+extern int xfs_contig_bits(uint *map, uint size, uint start_bit);
+
+/* Find next set bit in map */
+extern int xfs_next_bit(uint *map, uint size, uint start_bit);
+
+#endif /* __XFS_BIT_H__ */