diff options
Diffstat (limited to 'fs/xfs/xfs_bit.c')
| -rw-r--r-- | fs/xfs/xfs_bit.c | 91 |
1 files changed, 9 insertions, 82 deletions
diff --git a/fs/xfs/xfs_bit.c b/fs/xfs/xfs_bit.c index 1afe07f67e3b..fab0b6d5a41b 100644 --- a/fs/xfs/xfs_bit.c +++ b/fs/xfs/xfs_bit.c @@ -66,44 +66,6 @@ static const char xfs_highbit[256] = { #endif /* - * Count of bits set in byte, 0..8. - */ -static const char xfs_countbit[256] = { - 0, 1, 1, 2, 1, 2, 2, 3, /* 00 .. 07 */ - 1, 2, 2, 3, 2, 3, 3, 4, /* 08 .. 0f */ - 1, 2, 2, 3, 2, 3, 3, 4, /* 10 .. 17 */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 18 .. 1f */ - 1, 2, 2, 3, 2, 3, 3, 4, /* 20 .. 27 */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 28 .. 2f */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 30 .. 37 */ - 3, 4, 4, 5, 4, 5, 5, 6, /* 38 .. 3f */ - 1, 2, 2, 3, 2, 3, 3, 4, /* 40 .. 47 */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 48 .. 4f */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 50 .. 57 */ - 3, 4, 4, 5, 4, 5, 5, 6, /* 58 .. 5f */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 60 .. 67 */ - 3, 4, 4, 5, 4, 5, 5, 6, /* 68 .. 6f */ - 3, 4, 4, 5, 4, 5, 5, 6, /* 70 .. 77 */ - 4, 5, 5, 6, 5, 6, 6, 7, /* 78 .. 7f */ - 1, 2, 2, 3, 2, 3, 3, 4, /* 80 .. 87 */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 88 .. 8f */ - 2, 3, 3, 4, 3, 4, 4, 5, /* 90 .. 97 */ - 3, 4, 4, 5, 4, 5, 5, 6, /* 98 .. 9f */ - 2, 3, 3, 4, 3, 4, 4, 5, /* a0 .. a7 */ - 3, 4, 4, 5, 4, 5, 5, 6, /* a8 .. af */ - 3, 4, 4, 5, 4, 5, 5, 6, /* b0 .. b7 */ - 4, 5, 5, 6, 5, 6, 6, 7, /* b8 .. bf */ - 2, 3, 3, 4, 3, 4, 4, 5, /* c0 .. c7 */ - 3, 4, 4, 5, 4, 5, 5, 6, /* c8 .. cf */ - 3, 4, 4, 5, 4, 5, 5, 6, /* d0 .. d7 */ - 4, 5, 5, 6, 5, 6, 6, 7, /* d8 .. df */ - 3, 4, 4, 5, 4, 5, 5, 6, /* e0 .. e7 */ - 4, 5, 5, 6, 5, 6, 6, 7, /* e8 .. ef */ - 4, 5, 5, 6, 5, 6, 6, 7, /* f0 .. f7 */ - 5, 6, 6, 7, 6, 7, 7, 8, /* f8 .. ff */ -}; - -/* * xfs_highbit32: get high bit set out of 32-bit argument, -1 if none set. */ inline int @@ -167,56 +129,21 @@ xfs_highbit64( /* - * Count the number of bits set in the bitmap starting with bit - * start_bit. Size is the size of the bitmap in words. - * - * Do the counting by mapping a byte value to the number of set - * bits for that value using the xfs_countbit array, i.e. - * xfs_countbit[0] == 0, xfs_countbit[1] == 1, xfs_countbit[2] == 1, - * xfs_countbit[3] == 2, etc. + * Return whether bitmap is empty. + * Size is number of words in the bitmap, which is padded to word boundary + * Returns 1 for empty, 0 for non-empty. */ int -xfs_count_bits(uint *map, uint size, uint start_bit) +xfs_bitmap_empty(uint *map, uint size) { - register int bits; - register unsigned char *bytep; - register unsigned char *end_map; - int byte_bit; - - bits = 0; - end_map = (char*)(map + size); - bytep = (char*)(map + (start_bit & ~0x7)); - byte_bit = start_bit & 0x7; - - /* - * If the caller fell off the end of the map, return 0. - */ - if (bytep >= end_map) { - return (0); - } - - /* - * If start_bit is not byte aligned, then process the - * first byte separately. - */ - if (byte_bit != 0) { - /* - * Shift off the bits we don't want to look at, - * before indexing into xfs_countbit. - */ - bits += xfs_countbit[(*bytep >> byte_bit)]; - bytep++; - } + uint i; + uint ret = 0; - /* - * Count the bits in each byte until the end of the bitmap. - */ - while (bytep < end_map) { - bits += xfs_countbit[*bytep]; - bytep++; + for (i = 0; i < size; i++) { + ret |= map[i]; } - return (bits); + return (ret == 0); } /* |