include/xfs_bit.h

   1 /*
   2  * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31  */
  32 #ifndef __XFS_BIT_H__
  33 #define __XFS_BIT_H__
  34
  35 /*
  36  * XFS bit manipulation routines.
  37  */
  38
  39 /*
  40  * masks with n high/low bits set, 32-bit values & 64-bit values
  41  */
  42 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_MASK32HI)
  43 __uint32_t xfs_mask32hi(int n);
  44 #define XFS_MASK32HI(n)         xfs_mask32hi(n)
  45 #else
  46 #define XFS_MASK32HI(n)         ((__uint32_t)-1 << (32 - (n)))
  47 #endif
  48 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_MASK64HI)
  49 __uint64_t xfs_mask64hi(int n);
  50 #define XFS_MASK64HI(n)         xfs_mask64hi(n)
  51 #else
  52 #define XFS_MASK64HI(n)         ((__uint64_t)-1 << (64 - (n)))
  53 #endif
  54 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_MASK32LO)
  55 __uint32_t xfs_mask32lo(int n);
  56 #define XFS_MASK32LO(n)         xfs_mask32lo(n)
  57 #else
  58 #define XFS_MASK32LO(n)         (((__uint32_t)1 << (n)) - 1)
  59 #endif
  60 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_MASK64LO)
  61 __uint64_t xfs_mask64lo(int n);
  62 #define XFS_MASK64LO(n)         xfs_mask64lo(n)
  63 #else
  64 #define XFS_MASK64LO(n)         (((__uint64_t)1 << (n)) - 1)
  65 #endif
  66
  67 /*
  68  * Index of low bit number in byte, -1 for none set, 0..7 otherwise.
  69  */
  70 extern const char xfs_lowbit[256];
  71
  72 /*
  73  * Index of high bit number in byte, -1 for none set, 0..7 otherwise.
  74  */
  75 extern const char xfs_highbit[256];
  76
  77 /*
  78  * Count of bits set in byte, 0..8.
  79  */
  80 extern const char xfs_countbit[256];
  81
  82 /*
  83  * xfs_lowbit32: get low bit set out of 32-bit argument, -1 if none set.
  84  */
  85 extern int xfs_lowbit32(__uint32_t v);
  86
  87 /*
  88  * xfs_highbit32: get high bit set out of 32-bit argument, -1 if none set.
  89  */
  90 extern int xfs_highbit32(__uint32_t v);
  91
  92 /*
  93  * xfs_lowbit64: get low bit set out of 64-bit argument, -1 if none set.
  94  */
  95 extern int xfs_lowbit64(__uint64_t v);
  96
  97 /*
  98  * xfs_highbit64: get high bit set out of 64-bit argument, -1 if none set.
  99  */
 100 extern int xfs_highbit64(__uint64_t);
 101
 102 #endif  /* __XFS_BIT_H__ */