/* lzo_ptr.h -- low-level pointer constructs
This file is part of the LZO real-time data compression library.
Copyright (C) 1996-2002 Markus Franz Xaver Johannes Oberhumer
All Rights Reserved.
The LZO library 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; either version 2 of
the License, or (at your option) any later version.
The LZO library is distributed in the hope that it will 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 the LZO library; see the file COPYING.
If not, write to the Free Software Foundation, Inc.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
Markus F.X.J. Oberhumer
<markus@oberhumer.com>
*/
/* WARNING: this file should *not* be used by applications. It is
part of the implementation of the library and is subject
to change.
*/
#ifndef __LZO_PTR_H
#define __LZO_PTR_H
#ifdef __cplusplus
extern "C" {
#endif
/* This is the lowest part of the LZO library.
* It deals with pointer representations at bit level.
*/
/***********************************************************************
// Includes
************************************************************************/
#if defined(__LZO_DOS16) || defined(__LZO_WIN16)
# include <dos.h>
# if 1 && defined(__WATCOMC__)
# include <i86.h>
__LZO_EXTERN_C unsigned char _HShift;
# define __LZO_HShift _HShift
# elif 1 && defined(_MSC_VER)
__LZO_EXTERN_C unsigned short __near _AHSHIFT;
# define __LZO_HShift ((unsigned) &_AHSHIFT)
# elif defined(__LZO_WIN16)
# define __LZO_HShift 3
# else
# define __LZO_HShift 12
# endif
# if !defined(_FP_SEG) && defined(FP_SEG)
# define _FP_SEG FP_SEG
# endif
# if !defined(_FP_OFF) && defined(FP_OFF)
# define _FP_OFF FP_OFF
# endif
#endif
/***********************************************************************
// Integral types
************************************************************************/
/* ptrdiff_t */
#if !defined(lzo_ptrdiff_t)
# if (UINT_MAX >= LZO_0xffffffffL)
typedef ptrdiff_t lzo_ptrdiff_t;
# else
typedef long lzo_ptrdiff_t;
# endif
#endif
/* Integral types that have *exactly* the same number of bits as a lzo_voidp */
#if !defined(__LZO_HAVE_PTR_T)
# if defined(lzo_ptr_t)
# define __LZO_HAVE_PTR_T
# endif
#endif
#if !defined(__LZO_HAVE_PTR_T)
# if defined(SIZEOF_CHAR_P) && defined(SIZEOF_UNSIGNED_LONG)
# if (SIZEOF_CHAR_P == SIZEOF_UNSIGNED_LONG)
typedef unsigned long lzo_ptr_t;
typedef long lzo_sptr_t;
# define __LZO_HAVE_PTR_T
# endif
# endif
#endif
#if !defined(__LZO_HAVE_PTR_T)
# if defined(SIZEOF_CHAR_P) && defined(SIZEOF_UNSIGNED)
# if (SIZEOF_CHAR_P == SIZEOF_UNSIGNED)
typedef unsigned int lzo_ptr_t;
typedef int lzo_sptr_t;
# define __LZO_HAVE_PTR_T
# endif
# endif
#endif
#if !defined(__LZO_HAVE_PTR_T)
# if defined(SIZEOF_CHAR_P) && defined(SIZEOF_UNSIGNED_SHORT)
# if (SIZEOF_CHAR_P == SIZEOF_UNSIGNED_SHORT)
typedef unsigned short lzo_ptr_t;
typedef short lzo_sptr_t;
# define __LZO_HAVE_PTR_T
# endif
# endif
#endif
#if !defined(__LZO_HAVE_PTR_T)
# if defined(LZO_HAVE_CONFIG_H) || defined(SIZEOF_CHAR_P)
# error "no suitable type for lzo_ptr_t"
# else
typedef unsigned long lzo_ptr_t;
typedef long lzo_sptr_t;
# define __LZO_HAVE_PTR_T
# endif
#endif
/***********************************************************************
//
************************************************************************/
/* Always use the integral version for pointer comparisions.
*
* Note that this only works if the representation and ordering
* of the pointer and the integral is the same (at bit level).
*/
#if defined(__LZO_DOS16) || defined(__LZO_WIN16)
#define PTR(a) ((lzo_bytep) (a))
/* only need the low bits of the pointer -> offset is ok */
#define PTR_ALIGNED_4(a) ((_FP_OFF(a) & 3) == 0)
#define PTR_ALIGNED2_4(a,b) (((_FP_OFF(a) | _FP_OFF(b)) & 3) == 0)
#else
#define PTR(a) ((lzo_ptr_t) (a))
#define PTR_LINEAR(a) PTR(a)
#define PTR_ALIGNED_4(a) ((PTR_LINEAR(a) & 3) == 0)
#define PTR_ALIGNED_8(a) ((PTR_LINEAR(a) & 7) == 0)
#define PTR_ALIGNED2_4(a,b) (((PTR_LINEAR(a) | PTR_LINEAR(b)) & 3) == 0)
#define PTR_ALIGNED2_8(a,b) (((PTR_LINEAR(a) | PTR_LINEAR(b)) & 7) == 0)
#endif
#define PTR_LT(a,b) (PTR(a) < PTR(b))
#define PTR_GE(a,b) (PTR(a) >= PTR(b))
#define PTR_DIFF(a,b) ((lzo_ptrdiff_t) (PTR(a) - PTR(b)))
#define pd(a,b) ((lzo_uint) ((a)-(b)))
LZO_EXTERN(lzo_ptr_t)
__lzo_ptr_linear(const lzo_voidp ptr);
typedef union
{
char a_char;
unsigned char a_uchar;
short a_short;
unsigned short a_ushort;
int a_int;
unsigned int a_uint;
long a_long;
unsigned long a_ulong;
lzo_int a_lzo_int;
lzo_uint a_lzo_uint;
lzo_int32 a_lzo_int32;
lzo_uint32 a_lzo_uint32;
ptrdiff_t a_ptrdiff_t;
lzo_ptrdiff_t a_lzo_ptrdiff_t;
lzo_ptr_t a_lzo_ptr_t;
lzo_voidp a_lzo_voidp;
void * a_void_p;
lzo_bytep a_lzo_bytep;
lzo_bytepp a_lzo_bytepp;
lzo_uintp a_lzo_uintp;
lzo_uint * a_lzo_uint_p;
lzo_uint32p a_lzo_uint32p;
lzo_uint32 * a_lzo_uint32_p;
unsigned char * a_uchar_p;
char * a_char_p;
}
lzo_full_align_t;
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* already included */
/*
vi:ts=4:et
*/