xfs/libxfs/xfs_bit.c

1 // SPDX-License-Identifier: GPL-2.0
3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
11  * XFS bit manipulation routines, used in non-realtime code.
15  * Return whether bitmap is empty.
17  * Returns 1 for empty, 0 for non-empty.
46 	size -= start_bit & ~(NBWORD - 1);  in xfs_contig_bits()
47 	start_bit &= (NBWORD - 1);  in xfs_contig_bits()
51 		tmp |= (~0U >> (NBWORD-start_bit));  in xfs_contig_bits()
55 		size -= NBWORD;  in xfs_contig_bits()
61 		size -= NBWORD;  in xfs_contig_bits()
63 	return result - start_bit;  in xfs_contig_bits()
65 	return result + ffz(tmp) - start_bit;  in xfs_contig_bits()
70  * returns the next set bit from there.  It returns -1
79 	uint result = start_bit & ~(NBWORD - 1);  in xfs_next_bit()
85 		return -1;  in xfs_next_bit()
86 	size -= result;  in xfs_next_bit()
87 	start_bit &= (NBWORD - 1);  in xfs_next_bit()
95 		size -= NBWORD;  in xfs_next_bit()
101 		size -= NBWORD;  in xfs_next_bit()
103 	return -1;  in xfs_next_bit()
105 	return result + ffs(tmp) - 1;  in xfs_next_bit()