tools/ucl/src/ucl_ptr.c

   1 /* ucl_ptr.c -- low-level pointer constructs
   2
   3    This file is part of the UCL data compression library.
   4
   5    Copyright (C) 1996-2002 Markus Franz Xaver Johannes Oberhumer
   6    All Rights Reserved.
   7
   8    The UCL library is free software; you can redistribute it and/or
   9    modify it under the terms of the GNU General Public License as
  10    published by the Free Software Foundation; either version 2 of
  11    the License, or (at your option) any later version.
  12
  13    The UCL library is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with the UCL library; see the file COPYING.
  20    If not, write to the Free Software Foundation, Inc.,
  21    59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  22
  23    Markus F.X.J. Oberhumer
  24    <markus@oberhumer.com>
  25    http://www.oberhumer.com/opensource/ucl/
  26  */
  27
  28
  29 #include "ucl_conf.h"
  30
  31
  32 /***********************************************************************
  33 //
  34 ************************************************************************/
  35
  36 UCL_PUBLIC(ucl_ptr_t)
  37 __ucl_ptr_linear(const ucl_voidp ptr)
  38 {
  39     ucl_ptr_t p;
  40
  41 #if defined(__UCL_DOS16) || defined(__UCL_WIN16)
  42     p = (((ucl_ptr_t)(_FP_SEG(ptr))) << (16 - __UCL_HShift)) + (_FP_OFF(ptr));
  43 #else
  44     p = PTR_LINEAR(ptr);
  45 #endif
  46
  47     return p;
  48 }
  49
  50
  51 /***********************************************************************
  52 //
  53 ************************************************************************/
  54
  55 UCL_PUBLIC(unsigned)
  56 __ucl_align_gap(const ucl_voidp ptr, ucl_uint size)
  57 {
  58     ucl_ptr_t p, s, n;
  59
  60     assert(size > 0);
  61
  62     p = __ucl_ptr_linear(ptr);
  63     s = (ucl_ptr_t) (size - 1);
  64 #if 0
  65     assert((size & (size - 1)) == 0);
  66     n = ((p + s) & ~s) - p;
  67 #else
  68     n = (((p + s) / size) * size) - p;
  69 #endif
  70
  71     assert((long)n >= 0);
  72     assert(n <= s);
  73
  74     return (unsigned)n;
  75 }
  76
  77
  78
  79 /*
  80 vi:ts=4:et
  81 */