File: [Development] / xfs-cmds / xfsprogs / libxfs / Attic / bit.c (download)
Revision 1.4, Thu Apr 27 15:40:54 2006 UTC (11 years, 5 months ago) by nathans.longdrop.melbourne.sgi.com
Branch: MAIN
Changes since 1.3: +0 -38
lines
Backport xfs_repair from the xfs-cmds tree to IRIX to aid parallel repair merging later.
Merge of master-melb:xfs-cmds:25838a by kenmcd.
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/*
* 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
*/
/*
* XFS bit manipulation routines
*/
#include <xfs.h>
/*
* Index of low bit number in byte, -1 for none set, 0..7 otherwise.
*/
static const char xfs_lowbit[256] = {
-1, 0, 1, 0, 2, 0, 1, 0, /* 00 .. 07 */
3, 0, 1, 0, 2, 0, 1, 0, /* 08 .. 0f */
4, 0, 1, 0, 2, 0, 1, 0, /* 10 .. 17 */
3, 0, 1, 0, 2, 0, 1, 0, /* 18 .. 1f */
5, 0, 1, 0, 2, 0, 1, 0, /* 20 .. 27 */
3, 0, 1, 0, 2, 0, 1, 0, /* 28 .. 2f */
4, 0, 1, 0, 2, 0, 1, 0, /* 30 .. 37 */
3, 0, 1, 0, 2, 0, 1, 0, /* 38 .. 3f */
6, 0, 1, 0, 2, 0, 1, 0, /* 40 .. 47 */
3, 0, 1, 0, 2, 0, 1, 0, /* 48 .. 4f */
4, 0, 1, 0, 2, 0, 1, 0, /* 50 .. 57 */
3, 0, 1, 0, 2, 0, 1, 0, /* 58 .. 5f */
5, 0, 1, 0, 2, 0, 1, 0, /* 60 .. 67 */
3, 0, 1, 0, 2, 0, 1, 0, /* 68 .. 6f */
4, 0, 1, 0, 2, 0, 1, 0, /* 70 .. 77 */
3, 0, 1, 0, 2, 0, 1, 0, /* 78 .. 7f */
7, 0, 1, 0, 2, 0, 1, 0, /* 80 .. 87 */
3, 0, 1, 0, 2, 0, 1, 0, /* 88 .. 8f */
4, 0, 1, 0, 2, 0, 1, 0, /* 90 .. 97 */
3, 0, 1, 0, 2, 0, 1, 0, /* 98 .. 9f */
5, 0, 1, 0, 2, 0, 1, 0, /* a0 .. a7 */
3, 0, 1, 0, 2, 0, 1, 0, /* a8 .. af */
4, 0, 1, 0, 2, 0, 1, 0, /* b0 .. b7 */
3, 0, 1, 0, 2, 0, 1, 0, /* b8 .. bf */
6, 0, 1, 0, 2, 0, 1, 0, /* c0 .. c7 */
3, 0, 1, 0, 2, 0, 1, 0, /* c8 .. cf */
4, 0, 1, 0, 2, 0, 1, 0, /* d0 .. d7 */
3, 0, 1, 0, 2, 0, 1, 0, /* d8 .. df */
5, 0, 1, 0, 2, 0, 1, 0, /* e0 .. e7 */
3, 0, 1, 0, 2, 0, 1, 0, /* e8 .. ef */
4, 0, 1, 0, 2, 0, 1, 0, /* f0 .. f7 */
3, 0, 1, 0, 2, 0, 1, 0, /* f8 .. ff */
};
/*
* 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 */
};
/*
* xfs_lowbit32: get low bit set out of 32-bit argument, -1 if none set.
*/
int
xfs_lowbit32(
__uint32_t v)
{
int i;
if (v & 0x0000ffff)
if (v & 0x000000ff)
i = 0;
else
i = 8;
else if (v & 0xffff0000)
if (v & 0x00ff0000)
i = 16;
else
i = 24;
else
return -1;
return i + xfs_lowbit[(v >> i) & 0xff];
}
/*
* xfs_highbit32: get high bit set out of 32-bit argument, -1 if none set.
*/
int
xfs_highbit32(
__uint32_t v)
{
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];
}
/*
* xfs_lowbit64: get low bit set out of 64-bit argument, -1 if none set.
*/
int
xfs_lowbit64(
__uint64_t v)
{
int i;
#if XFS_64
if (v & 0x00000000ffffffff)
if (v & 0x000000000000ffff)
if (v & 0x00000000000000ff)
i = 0;
else
i = 8;
else
if (v & 0x0000000000ff0000)
i = 16;
else
i = 24;
else if (v & 0xffffffff00000000)
if (v & 0x0000ffff00000000)
if (v & 0x000000ff00000000)
i = 32;
else
i = 40;
else
if (v & 0x00ff000000000000)
i = 48;
else
i = 56;
else
return -1;
return i + xfs_lowbit[(v >> i) & 0xff];
#else
__uint32_t vw;
if ((vw = v)) {
if (vw & 0x0000ffff)
if (vw & 0x000000ff)
i = 0;
else
i = 8;
else
if (vw & 0x00ff0000)
i = 16;
else
i = 24;
return i + xfs_lowbit[(vw >> i) & 0xff];
} else if ((vw = v >> 32)) {
if (vw & 0x0000ffff)
if (vw & 0x000000ff)
i = 32;
else
i = 40;
else
if (vw & 0x00ff0000)
i = 48;
else
i = 56;
return i + xfs_lowbit[(vw >> (i - 32)) & 0xff];
} else
return -1;
#endif
}
/*
* xfs_highbit64: get high bit set out of 64-bit argument, -1 if none set.
*/
int
xfs_highbit64(
__uint64_t v)
{
int i;
#if XFS_64
if (v & 0xffffffff00000000)
if (v & 0xffff000000000000)
if (v & 0xff00000000000000)
i = 56;
else
i = 48;
else
if (v & 0x0000ff0000000000)
i = 40;
else
i = 32;
else if (v & 0x00000000ffffffff)
if (v & 0x00000000ffff0000)
if (v & 0x00000000ff000000)
i = 24;
else
i = 16;
else
if (v & 0x000000000000ff00)
i = 8;
else
i = 0;
else
return -1;
return i + xfs_highbit[(v >> i) & 0xff];
#else
__uint32_t vw;
if ((vw = v >> 32)) {
if (vw & 0xffff0000)
if (vw & 0xff000000)
i = 56;
else
i = 48;
else
if (vw & 0x0000ff00)
i = 40;
else
i = 32;
return i + xfs_highbit[(vw >> (i - 32)) & 0xff];
} else if ((vw = v)) {
if (vw & 0xffff0000)
if (vw & 0xff000000)
i = 24;
else
i = 16;
else
if (vw & 0x0000ff00)
i = 8;
else
i = 0;
return i + xfs_highbit[(vw >> i) & 0xff];
} else
return -1;
#endif
}
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