lzo/src/lzo_ptr.h

   1 /* lzo_ptr.h -- low-level pointer constructs
   2
   3    This file is part of the LZO real-time data compression library.
   4
   5    Copyright (C) 2008 Markus Franz Xaver Johannes Oberhumer
   6    Copyright (C) 2007 Markus Franz Xaver Johannes Oberhumer
   7    Copyright (C) 2006 Markus Franz Xaver Johannes Oberhumer
   8    Copyright (C) 2005 Markus Franz Xaver Johannes Oberhumer
   9    Copyright (C) 2004 Markus Franz Xaver Johannes Oberhumer
  10    Copyright (C) 2003 Markus Franz Xaver Johannes Oberhumer
  11    Copyright (C) 2002 Markus Franz Xaver Johannes Oberhumer
  12    Copyright (C) 2001 Markus Franz Xaver Johannes Oberhumer
  13    Copyright (C) 2000 Markus Franz Xaver Johannes Oberhumer
  14    Copyright (C) 1999 Markus Franz Xaver Johannes Oberhumer
  15    Copyright (C) 1998 Markus Franz Xaver Johannes Oberhumer
  16    Copyright (C) 1997 Markus Franz Xaver Johannes Oberhumer
  17    Copyright (C) 1996 Markus Franz Xaver Johannes Oberhumer
  18    All Rights Reserved.
  19
  20    The LZO library is free software; you can redistribute it and/or
  21    modify it under the terms of the GNU General Public License as
  22    published by the Free Software Foundation; either version 2 of
  23    the License, or (at your option) any later version.
  24
  25    The LZO library is distributed in the hope that it will be useful,
  26    but WITHOUT ANY WARRANTY; without even the implied warranty of
  27    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28    GNU General Public License for more details.
  29
  30    You should have received a copy of the GNU General Public License
  31    along with the LZO library; see the file COPYING.
  32    If not, write to the Free Software Foundation, Inc.,
  33    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  34
  35    Markus F.X.J. Oberhumer
  36    <markus@oberhumer.com>
  37    http://www.oberhumer.com/opensource/lzo/
  38  */
  39
  40
  41 /* WARNING: this file should *not* be used by applications. It is
  42    part of the implementation of the library and is subject
  43    to change.
  44  */
  45
  46
  47 #ifndef __LZO_PTR_H
  48 #define __LZO_PTR_H
  49
  50 #ifdef __cplusplus
  51 extern "C" {
  52 #endif
  53
  54
  55 /***********************************************************************
  56 // Integral types
  57 ************************************************************************/
  58
  59 #if !defined(lzo_uintptr_t)
  60 #  if defined(__LZO_MMODEL_HUGE)
  61 #    define lzo_uintptr_t   unsigned long
  62 #  else
  63 #    define lzo_uintptr_t   acc_uintptr_t
  64 #    ifdef __ACC_INTPTR_T_IS_POINTER
  65 #      define __LZO_UINTPTR_T_IS_POINTER 1
  66 #    endif
  67 #  endif
  68 #endif
  69
  70
  71 /***********************************************************************
  72 //
  73 ************************************************************************/
  74
  75 /* Always use the safe (=integral) version for pointer-comparisions.
  76  * The compiler should optimize away the additional casts anyway.
  77  *
  78  * Note that this only works if the representation and ordering
  79  * of the pointer and the integral is the same (at bit level).
  80  *
  81  * Most 16-bit compilers have their own view about pointers -
  82  * fortunately they don't care about comparing pointers
  83  * that are pointing to Nirvana.
  84  */
  85
  86 #if (LZO_ARCH_I086)
  87 #define PTR(a)              ((lzo_bytep) (a))
  88 /* only need the low bits of the pointer -> offset is ok */
  89 #define PTR_ALIGNED_4(a)    ((ACC_PTR_FP_OFF(a) & 3) == 0)
  90 #define PTR_ALIGNED2_4(a,b) (((ACC_PTR_FP_OFF(a) | ACC_PTR_FP_OFF(b)) & 3) == 0)
  91 #elif (LZO_MM_PVP)
  92 #define PTR(a)              ((lzo_bytep) (a))
  93 #define PTR_ALIGNED_8(a)    ((((lzo_uintptr_t)(a)) >> 61) == 0)
  94 #define PTR_ALIGNED2_8(a,b) ((((lzo_uintptr_t)(a)|(lzo_uintptr_t)(b)) >> 61) == 0)
  95 #else
  96 #define PTR(a)              ((lzo_uintptr_t) (a))
  97 #define PTR_LINEAR(a)       PTR(a)
  98 #define PTR_ALIGNED_4(a)    ((PTR_LINEAR(a) & 3) == 0)
  99 #define PTR_ALIGNED_8(a)    ((PTR_LINEAR(a) & 7) == 0)
 100 #define PTR_ALIGNED2_4(a,b) (((PTR_LINEAR(a) | PTR_LINEAR(b)) & 3) == 0)
 101 #define PTR_ALIGNED2_8(a,b) (((PTR_LINEAR(a) | PTR_LINEAR(b)) & 7) == 0)
 102 #endif
 103
 104 #define PTR_LT(a,b)         (PTR(a) < PTR(b))
 105 #define PTR_GE(a,b)         (PTR(a) >= PTR(b))
 106 #define PTR_DIFF(a,b)       (PTR(a) - PTR(b))
 107 #define pd(a,b)             ((lzo_uint) ((a)-(b)))
 108
 109
 110 LZO_EXTERN(lzo_uintptr_t)
 111 __lzo_ptr_linear(const lzo_voidp ptr);
 112
 113
 114 typedef union
 115 {
 116     char            a_char;
 117     unsigned char   a_uchar;
 118     short           a_short;
 119     unsigned short  a_ushort;
 120     int             a_int;
 121     unsigned int    a_uint;
 122     long            a_long;
 123     unsigned long   a_ulong;
 124     lzo_int         a_lzo_int;
 125     lzo_uint        a_lzo_uint;
 126     lzo_int32       a_lzo_int32;
 127     lzo_uint32      a_lzo_uint32;
 128     ptrdiff_t       a_ptrdiff_t;
 129     lzo_uintptr_t   a_lzo_uintptr_t;
 130     lzo_voidp       a_lzo_voidp;
 131     void *          a_void_p;
 132     lzo_bytep       a_lzo_bytep;
 133     lzo_bytepp      a_lzo_bytepp;
 134     lzo_uintp       a_lzo_uintp;
 135     lzo_uint *      a_lzo_uint_p;
 136     lzo_uint32p     a_lzo_uint32p;
 137     lzo_uint32 *    a_lzo_uint32_p;
 138     unsigned char * a_uchar_p;
 139     char *          a_char_p;
 140 }
 141 lzo_full_align_t;
 142
 143
 144
 145 #ifdef __cplusplus
 146 } /* extern "C" */
 147 #endif
 148
 149 #endif /* already included */
 150
 151 /*
 152 vi:ts=4:et
 153 */
 154