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foxbox/tools/ucl/src/ucl_ptr.h
Jens Arnold 7c21a96e9a Initial check-in of (stripped-down) UCL data compression library v 1.01 
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8087 a1c6a512-1295-4272-9138-f99709370657
2005-11-27 23:41:55 +00:00

211 lines
6 KiB
C
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/* ucl_ptr.h -- low-level pointer constructs
This file is part of the UCL data compression library.
Copyright (C) 1996-2002 Markus Franz Xaver Johannes Oberhumer
All Rights Reserved.
The UCL 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 UCL 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 UCL 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 __UCL_PTR_H
#define __UCL_PTR_H
#ifdef __cplusplus
extern "C" {
#endif
/* This is the lowest part of the UCL library.
* It deals with pointer representations at bit level.
*/
/***********************************************************************
// Includes
************************************************************************/
#if defined(__UCL_DOS16) || defined(__UCL_WIN16)
# include <dos.h>
# if 1 && defined(__WATCOMC__)
# include <i86.h>
__UCL_EXTERN_C unsigned char _HShift;
# define __UCL_HShift _HShift
# elif 1 && defined(_MSC_VER)
__UCL_EXTERN_C unsigned short __near _AHSHIFT;
# define __UCL_HShift ((unsigned) &_AHSHIFT)
# elif defined(__UCL_WIN16)
# define __UCL_HShift 3
# else
# define __UCL_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(ucl_ptrdiff_t)
#if (UINT_MAX >= UCL_0xffffffffL)
typedef ptrdiff_t ucl_ptrdiff_t;
#else
typedef long ucl_ptrdiff_t;
#endif
#endif
/* Unsigned type that has *exactly* the same number of bits as a ucl_voidp */
#if !defined(__UCL_HAVE_PTR_T)
# if defined(ucl_ptr_t)
# define __UCL_HAVE_PTR_T
# endif
#endif
#if !defined(__UCL_HAVE_PTR_T)
# if defined(SIZEOF_CHAR_P) && defined(SIZEOF_UNSIGNED_LONG)
# if (SIZEOF_CHAR_P == SIZEOF_UNSIGNED_LONG)
typedef unsigned long ucl_ptr_t;
typedef long ucl_sptr_t;
# define __UCL_HAVE_PTR_T
# endif
# endif
#endif
#if !defined(__UCL_HAVE_PTR_T)
# if defined(SIZEOF_CHAR_P) && defined(SIZEOF_UNSIGNED)
# if (SIZEOF_CHAR_P == SIZEOF_UNSIGNED)
typedef unsigned int ucl_ptr_t;
typedef int ucl_sptr_t;
# define __UCL_HAVE_PTR_T
# endif
# endif
#endif
#if !defined(__UCL_HAVE_PTR_T)
# if defined(SIZEOF_CHAR_P) && defined(SIZEOF_UNSIGNED_SHORT)
# if (SIZEOF_CHAR_P == SIZEOF_UNSIGNED_SHORT)
typedef unsigned short ucl_ptr_t;
typedef short ucl_sptr_t;
# define __UCL_HAVE_PTR_T
# endif
# endif
#endif
#if !defined(__UCL_HAVE_PTR_T)
# if defined(UCL_HAVE_CONFIG_H) || defined(SIZEOF_CHAR_P)
# error "no suitable type for ucl_ptr_t"
# else
typedef unsigned long ucl_ptr_t;
typedef long ucl_sptr_t;
# define __UCL_HAVE_PTR_T
# endif
#endif
/***********************************************************************
//
************************************************************************/
/* Always use the safe (=integral) version for pointer-comparisions.
* The compiler should optimize away the additional casts anyway.
*
* Note that this only works if the representation and ordering
* of the pointer and the integral is the same (at bit level).
*
* Most 16-bit compilers have their own view about pointers -
* fortunately they don't care about comparing pointers
* that are pointing to Nirvana.
*/
#if defined(__UCL_DOS16) || defined(__UCL_WIN16)
#define PTR(a) ((ucl_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) ((ucl_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) ((ucl_ptrdiff_t) (PTR(a) - PTR(b)))
UCL_EXTERN(ucl_ptr_t)
__ucl_ptr_linear(const ucl_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;
ucl_int a_ucl_int;
ucl_uint a_ucl_uint;
ucl_int32 a_ucl_int32;
ucl_uint32 a_ucl_uint32;
ptrdiff_t a_ptrdiff_t;
ucl_ptrdiff_t a_ucl_ptrdiff_t;
ucl_ptr_t a_ucl_ptr_t;
ucl_voidp a_ucl_voidp;
void * a_void_p;
ucl_bytep a_ucl_bytep;
ucl_bytepp a_ucl_bytepp;
ucl_uintp a_ucl_uintp;
ucl_uint * a_ucl_uint_p;
ucl_uint32p a_ucl_uint32p;
ucl_uint32 * a_ucl_uint32_p;
unsigned char * a_uchar_p;
char * a_char_p;
}
ucl_align_t;
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* already included */
/*
vi:ts=4:et
*/
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