HLab: H:/Class/11756/HLab/sphinxbase-0.4/include/byteorder.h Source File

00001 /* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */
00002 /* ====================================================================
00003  * Copyright (c) 1999-2001 Carnegie Mellon University.  All rights
00004  * reserved.
00005  *
00006  * Redistribution and use in source and binary forms, with or without
00007  * modification, are permitted provided that the following conditions
00008  * are met:
00009  *
00010  * 1. Redistributions of source code must retain the above copyright
00011  *    notice, this list of conditions and the following disclaimer. 
00012  *
00013  * 2. Redistributions in binary form must reproduce the above copyright
00014  *    notice, this list of conditions and the following disclaimer in
00015  *    the documentation and/or other materials provided with the
00016  *    distribution.
00017  *
00018  * This work was supported in part by funding from the Defense Advanced 
00019  * Research Projects Agency and the National Science Foundation of the 
00020  * United States of America, and the CMU Sphinx Speech Consortium.
00021  *
00022  * THIS SOFTWARE IS PROVIDED BY CARNEGIE MELLON UNIVERSITY ``AS IS'' AND 
00023  * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 
00024  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
00025  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY
00026  * NOR ITS EMPLOYEES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00027  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
00028  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 
00029  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
00030  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
00031  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
00032  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00033  *
00034  * ====================================================================
00035  *
00036  */
00037 
00038 /*
00039  * byteorder.h -- Byte swapping ordering macros.
00040  * 
00041  * **********************************************
00042  * CMU ARPA Speech Project
00043  *
00044  * Copyright (c) 1996 Carnegie Mellon University.
00045  * ALL RIGHTS RESERVED.
00046  * **********************************************
00047  * 
00048  * HISTORY
00049  * 
00050  * $Log: byteorder.h,v $
00051  * Revision 1.8  2005/09/01 21:09:54  dhdfu
00052  * Really, actually, truly consolidate byteswapping operations into
00053  * byteorder.h.  Where unconditional byteswapping is needed, SWAP_INT32()
00054  * and SWAP_INT16() are to be used.  The WORDS_BIGENDIAN macro from
00055  * autoconf controls the functioning of the conditional swap macros
00056  * (SWAP_?[LW]) whose names and semantics have been regularized.
00057  * Private, adhoc macros have been removed.
00058  *
00059  */
00060 
00061 #ifndef __S2_BYTEORDER_H__
00062 #define __S2_BYTEORDER_H__      1
00063 
00064 /* Macro to byteswap an int16 variable.  x = ptr to variable */
00065 #define SWAP_INT16(x)   *(x) = ((0x00ff & (*(x))>>8) | (0xff00 & (*(x))<<8))
00066 
00067 /* Macro to byteswap an int32 variable.  x = ptr to variable */
00068 #define SWAP_INT32(x)   *(x) = ((0x000000ff & (*(x))>>24) | \
00069                                 (0x0000ff00 & (*(x))>>8) | \
00070                                 (0x00ff0000 & (*(x))<<8) | \
00071                                 (0xff000000 & (*(x))<<24))
00072 
00073 /* Macro to byteswap a float32 variable.  x = ptr to variable */
00074 #define SWAP_FLOAT32(x) SWAP_INT32((int32 *) x)
00075 
00076 /* Macro to byteswap a float64 variable.  x = ptr to variable */
00077 #define SWAP_FLOAT64(x) { int *low = (int *) (x), *high = (int *) (x) + 1,\
00078                               temp;\
00079                           SWAP_INT32(low);  SWAP_INT32(high);\
00080                           temp = *low; *low = *high; *high = temp;}
00081 
00082 /* Rather confusing backwards compatibility macros for dealing with
00083  * explicitly big or little-endian data. */
00084 #ifdef WORDS_BIGENDIAN
00085 #define SWAP_BE_64(x)
00086 #define SWAP_BE_32(x)
00087 #define SWAP_BE_16(x)
00088 #define SWAP_LE_64(x) SWAP_FLOAT64(x)
00089 #define SWAP_LE_32(x) SWAP_INT32(x)
00090 #define SWAP_LE_16(x) SWAP_INT16(x)
00091 #else
00092 #define SWAP_LE_64(x)
00093 #define SWAP_LE_32(x)
00094 #define SWAP_LE_16(x)
00095 #define SWAP_BE_64(x) SWAP_FLOAT64(x)
00096 #define SWAP_BE_32(x) SWAP_INT32(x)
00097 #define SWAP_BE_16(x) SWAP_INT16(x)
00098 #endif
00099 
00100 #endif