85 lines
2.1 KiB
C
85 lines
2.1 KiB
C
/*
|
|
* 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)))
|
|
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__ */
|