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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__ */
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