197 lines
5.5 KiB
C
197 lines
5.5 KiB
C
/*
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* This source code may contain confidential information of QNX Software
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* Systems Ltd. (QSSL) and its licensors. Any use, reproduction,
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* modification, disclosure, distribution or transfer of this software,
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* or any software which includes or is based upon any of this code, is
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* prohibited unless expressly authorized by QSSL by written agreement. For
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* more information (including whether this source code file has been
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* published) please email licensing@qnx.com.
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*/
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/* ucl_ptr.h -- low-level pointer constructs
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This file is part of the UCL real-time data compression library.
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Copyright (C) 1996-2000 Markus Franz Xaver Johannes Oberhumer
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Markus F.X.J. Oberhumer
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markus.oberhumer@jk.uni-linz.ac.at
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*/
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/* WARNING: this file should *not* be used by applications. It is
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part of the implementation of the library and is subject
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to change.
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*/
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#ifndef __UCL_PTR_H
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#define __UCL_PTR_H
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#ifdef __cplusplus
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extern "C" {
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#endif
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/* This is the lowest part of the UCL library.
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* It deals with pointer representations at bit level.
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*/
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/***********************************************************************
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// Includes
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************************************************************************/
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#if defined(__UCL_DOS16) || defined(__UCL_WIN16)
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# include <dos.h>
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# if 1 && defined(__WATCOMC__)
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# include <i86.h>
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__UCL_EXTERN_C unsigned char _HShift;
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# define __UCL_HShift _HShift
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# elif 1 && defined(_MSC_VER)
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__UCL_EXTERN_C unsigned short __near _AHSHIFT;
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# define __UCL_HShift ((unsigned) &_AHSHIFT)
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# elif defined(__UCL_WIN16)
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# define __UCL_HShift 3
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# else
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# define __UCL_HShift 12
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# endif
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# if !defined(_FP_SEG) && defined(FP_SEG)
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# define _FP_SEG FP_SEG
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# endif
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# if !defined(_FP_OFF) && defined(FP_OFF)
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# define _FP_OFF FP_OFF
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# endif
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#endif
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/***********************************************************************
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// Integral types
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************************************************************************/
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/* ptrdiff_t */
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#if (UINT_MAX >= UCL_0xffffffffL)
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typedef ptrdiff_t ucl_ptrdiff_t;
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#else
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typedef long ucl_ptrdiff_t;
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#endif
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/* Unsigned type that has *exactly* the same number of bits as a ucl_voidp */
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#if !defined(__UCL_HAVE_PTR_T)
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# if defined(ucl_ptr_t)
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# define __UCL_HAVE_PTR_T
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# endif
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#endif
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#if !defined(__UCL_HAVE_PTR_T)
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# if defined(SIZEOF_CHAR_P) && defined(SIZEOF_UNSIGNED_LONG)
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# if (SIZEOF_CHAR_P == SIZEOF_UNSIGNED_LONG)
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typedef unsigned long ucl_ptr_t;
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typedef long ucl_sptr_t;
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# define __UCL_HAVE_PTR_T
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# endif
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# endif
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#endif
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#if !defined(__UCL_HAVE_PTR_T)
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# if defined(SIZEOF_CHAR_P) && defined(SIZEOF_UNSIGNED)
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# if (SIZEOF_CHAR_P == SIZEOF_UNSIGNED)
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typedef unsigned int ucl_ptr_t;
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typedef int ucl_sptr_t;
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# define __UCL_HAVE_PTR_T
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# endif
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# endif
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#endif
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#if !defined(__UCL_HAVE_PTR_T)
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# if defined(SIZEOF_CHAR_P) && defined(SIZEOF_UNSIGNED_SHORT)
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# if (SIZEOF_CHAR_P == SIZEOF_UNSIGNED_SHORT)
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typedef unsigned short ucl_ptr_t;
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typedef short ucl_sptr_t;
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# define __UCL_HAVE_PTR_T
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# endif
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# endif
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#endif
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#if !defined(__UCL_HAVE_PTR_T)
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# if defined(UCL_HAVE_CONFIG_H) || defined(SIZEOF_CHAR_P)
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# error "no suitable type for ucl_ptr_t"
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# else
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typedef unsigned long ucl_ptr_t;
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typedef long ucl_sptr_t;
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# define __UCL_HAVE_PTR_T
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# endif
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#endif
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/***********************************************************************
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//
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************************************************************************/
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/* Always use the safe (=integral) version for pointer-comparisions.
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* The compiler should optimize away the additional casts anyway.
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*
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* Note that this only works if the representation and ordering
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* of the pointer and the integral is the same (at bit level).
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*
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* Most 16 bit compilers have their own view about pointers -
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* fortunately they don't care about comparing pointers
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* that are pointing to Nirvana.
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*/
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#if defined(__UCL_DOS16) || defined(__UCL_WIN16)
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#define PTR(a) ((ucl_bytep) (a))
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/* only need the low bits of the pointer -> offset is ok */
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#define PTR_ALIGNED_4(a) ((_FP_OFF(a) & 3) == 0)
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#define PTR_ALIGNED2_4(a,b) (((_FP_OFF(a) | _FP_OFF(b)) & 3) == 0)
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#else
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#define PTR(a) ((ucl_ptr_t) (a))
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#define PTR_LINEAR(a) PTR(a)
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#define PTR_ALIGNED_4(a) ((PTR_LINEAR(a) & 3) == 0)
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#define PTR_ALIGNED_8(a) ((PTR_LINEAR(a) & 7) == 0)
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#define PTR_ALIGNED2_4(a,b) (((PTR_LINEAR(a) | PTR_LINEAR(b)) & 3) == 0)
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#define PTR_ALIGNED2_8(a,b) (((PTR_LINEAR(a) | PTR_LINEAR(b)) & 7) == 0)
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#endif
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#define PTR_LT(a,b) (PTR(a) < PTR(b))
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#define PTR_GE(a,b) (PTR(a) >= PTR(b))
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#define PTR_DIFF(a,b) ((ucl_ptrdiff_t) (PTR(a) - PTR(b)))
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UCL_EXTERN(ucl_ptr_t)
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__ucl_ptr_linear(const ucl_voidp ptr);
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typedef union
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{
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char a_char;
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unsigned char a_uchar;
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short a_short;
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unsigned short a_ushort;
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int a_int;
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unsigned int a_uint;
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long a_long;
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unsigned long a_ulong;
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ucl_int a_ucl_int;
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ucl_uint a_ucl_uint;
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ucl_int32 a_ucl_int32;
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ucl_uint32 a_ucl_uint32;
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ptrdiff_t a_ptrdiff_t;
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ucl_ptrdiff_t a_ucl_ptrdiff_t;
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ucl_ptr_t a_ucl_ptr_t;
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char * a_charp;
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ucl_bytep a_ucl_bytep;
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ucl_bytepp a_ucl_bytepp;
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}
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ucl_align_t;
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#ifdef __cplusplus
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} /* extern "C" */
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#endif
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#endif /* already included */
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/*
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vi:ts=4:et
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*/
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