/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#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__ */