byteorder.h
/* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */
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* United States of America, and the CMU Sphinx Speech Consortium.
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/*
* byteorder.h -- Byte swapping ordering macros.
*
* **********************************************
* CMU ARPA Speech Project
*
* Copyright (c) 1996 Carnegie Mellon University.
* ALL RIGHTS RESERVED.
* **********************************************
*
* HISTORY
*
* $Log: byteorder.h,v $
* Revision 1.8 2005/09/01 21:09:54 dhdfu
* Really, actually, truly consolidate byteswapping operations into
* byteorder.h. Where unconditional byteswapping is needed, SWAP_INT32()
* and SWAP_INT16() are to be used. The WORDS_BIGENDIAN macro from
* autoconf controls the functioning of the conditional swap macros
* (SWAP_?[LW]) whose names and semantics have been regularized.
* Private, adhoc macros have been removed.
*
*/
#ifndef __S2_BYTEORDER_H__
#define __S2_BYTEORDER_H__ 1
/* Macro to byteswap an int16 variable. x = ptr to variable */
#define SWAP_INT16(x) *(x) = ((0x00ff & (*(x))>>8) | (0xff00 & (*(x))<<8))
/* Macro to byteswap an int32 variable. x = ptr to variable */
#define SWAP_INT32(x) *(x) = ((0x000000ff & (*(x))>>24) | \
(0x0000ff00 & (*(x))>>8) | \
(0x00ff0000 & (*(x))<<8) | \
(0xff000000 & (*(x))<<24))
/* Macro to byteswap a float32 variable. x = ptr to variable */
#define SWAP_FLOAT32(x) SWAP_INT32((int32 *) x)
/* Macro to byteswap a float64 variable. x = ptr to variable */
#define SWAP_FLOAT64(x) { int *low = (int *) (x), *high = (int *) (x) + 1,\
temp;\
SWAP_INT32(low); SWAP_INT32(high);\
temp = *low; *low = *high; *high = temp;}
#ifdef WORDS_BIGENDIAN
#define SWAP_BE_64(x)
#define SWAP_BE_32(x)
#define SWAP_BE_16(x)
#define SWAP_LE_64(x) SWAP_FLOAT64(x)
#define SWAP_LE_32(x) SWAP_INT32(x)
#define SWAP_LE_16(x) SWAP_INT16(x)
#else
#define SWAP_LE_64(x)
#define SWAP_LE_32(x)
#define SWAP_LE_16(x)
#define SWAP_BE_64(x) SWAP_FLOAT64(x)
#define SWAP_BE_32(x) SWAP_INT32(x)
#define SWAP_BE_16(x) SWAP_INT16(x)
#endif
#endif