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author | Lachlan McIlroy <lachlan@sgi.com> | 2008-02-26 06:00:22 (GMT) |
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committer | Lachlan McIlroy <lachlan@redback.melbourne.sgi.com> | 2008-02-26 06:05:44 (GMT) |
commit | ef8ece55d9b6825c28a5c1a4bd89b94040cb7b32 (patch) | |
tree | c086be0bf7ef1139db75d4fd084f2390545629e8 /fs/xfs/xfs_bit.c | |
parent | db69c915e67705daac25cad06d816c09be634de0 (diff) | |
download | linux-ef8ece55d9b6825c28a5c1a4bd89b94040cb7b32.tar.xz |
[XFS] Undo bit ops cleanup mod due to regression on 32-bit powermac
platform.
SGI-PV: 971186
SGI-Modid: xfs-linux-melb:xfs-kern:30559a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Diffstat (limited to 'fs/xfs/xfs_bit.c')
-rw-r--r-- | fs/xfs/xfs_bit.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/fs/xfs/xfs_bit.c b/fs/xfs/xfs_bit.c index 4822884..fab0b6d 100644 --- a/fs/xfs/xfs_bit.c +++ b/fs/xfs/xfs_bit.c @@ -25,6 +25,109 @@ * XFS bit manipulation routines, used in non-realtime code. */ +#ifndef HAVE_ARCH_HIGHBIT +/* + * Index of high bit number in byte, -1 for none set, 0..7 otherwise. + */ +static const char xfs_highbit[256] = { + -1, 0, 1, 1, 2, 2, 2, 2, /* 00 .. 07 */ + 3, 3, 3, 3, 3, 3, 3, 3, /* 08 .. 0f */ + 4, 4, 4, 4, 4, 4, 4, 4, /* 10 .. 17 */ + 4, 4, 4, 4, 4, 4, 4, 4, /* 18 .. 1f */ + 5, 5, 5, 5, 5, 5, 5, 5, /* 20 .. 27 */ + 5, 5, 5, 5, 5, 5, 5, 5, /* 28 .. 2f */ + 5, 5, 5, 5, 5, 5, 5, 5, /* 30 .. 37 */ + 5, 5, 5, 5, 5, 5, 5, 5, /* 38 .. 3f */ + 6, 6, 6, 6, 6, 6, 6, 6, /* 40 .. 47 */ + 6, 6, 6, 6, 6, 6, 6, 6, /* 48 .. 4f */ + 6, 6, 6, 6, 6, 6, 6, 6, /* 50 .. 57 */ + 6, 6, 6, 6, 6, 6, 6, 6, /* 58 .. 5f */ + 6, 6, 6, 6, 6, 6, 6, 6, /* 60 .. 67 */ + 6, 6, 6, 6, 6, 6, 6, 6, /* 68 .. 6f */ + 6, 6, 6, 6, 6, 6, 6, 6, /* 70 .. 77 */ + 6, 6, 6, 6, 6, 6, 6, 6, /* 78 .. 7f */ + 7, 7, 7, 7, 7, 7, 7, 7, /* 80 .. 87 */ + 7, 7, 7, 7, 7, 7, 7, 7, /* 88 .. 8f */ + 7, 7, 7, 7, 7, 7, 7, 7, /* 90 .. 97 */ + 7, 7, 7, 7, 7, 7, 7, 7, /* 98 .. 9f */ + 7, 7, 7, 7, 7, 7, 7, 7, /* a0 .. a7 */ + 7, 7, 7, 7, 7, 7, 7, 7, /* a8 .. af */ + 7, 7, 7, 7, 7, 7, 7, 7, /* b0 .. b7 */ + 7, 7, 7, 7, 7, 7, 7, 7, /* b8 .. bf */ + 7, 7, 7, 7, 7, 7, 7, 7, /* c0 .. c7 */ + 7, 7, 7, 7, 7, 7, 7, 7, /* c8 .. cf */ + 7, 7, 7, 7, 7, 7, 7, 7, /* d0 .. d7 */ + 7, 7, 7, 7, 7, 7, 7, 7, /* d8 .. df */ + 7, 7, 7, 7, 7, 7, 7, 7, /* e0 .. e7 */ + 7, 7, 7, 7, 7, 7, 7, 7, /* e8 .. ef */ + 7, 7, 7, 7, 7, 7, 7, 7, /* f0 .. f7 */ + 7, 7, 7, 7, 7, 7, 7, 7, /* f8 .. ff */ +}; +#endif + +/* + * xfs_highbit32: get high bit set out of 32-bit argument, -1 if none set. + */ +inline int +xfs_highbit32( + __uint32_t v) +{ +#ifdef HAVE_ARCH_HIGHBIT + return highbit32(v); +#else + int i; + + if (v & 0xffff0000) + if (v & 0xff000000) + i = 24; + else + i = 16; + else if (v & 0x0000ffff) + if (v & 0x0000ff00) + i = 8; + else + i = 0; + else + return -1; + return i + xfs_highbit[(v >> i) & 0xff]; +#endif +} + +/* + * xfs_lowbit64: get low bit set out of 64-bit argument, -1 if none set. + */ +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; +} + +/* + * xfs_highbit64: get high bit set out of 64-bit argument, -1 if none set. + */ +int +xfs_highbit64( + __uint64_t v) +{ + __uint32_t h = (__uint32_t)(v >> 32); + + if (h) + return xfs_highbit32(h) + 32; + return xfs_highbit32((__uint32_t)v); +} + + /* * Return whether bitmap is empty. * Size is number of words in the bitmap, which is padded to word boundary |