PLearn 0.1
byte_order.cc
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00001 // -*- C++ -*-
00002 
00003 // byte_order.h
00004 // Copyright (C) 1998-2002 Pascal Vincent
00005 //
00006 // Redistribution and use in source and binary forms, with or without
00007 // modification, are permitted provided that the following conditions are met:
00008 // 
00009 //  1. Redistributions of source code must retain the above copyright
00010 //     notice, this list of conditions and the following disclaimer.
00011 // 
00012 //  2. Redistributions in binary form must reproduce the above copyright
00013 //     notice, this list of conditions and the following disclaimer in the
00014 //     documentation and/or other materials provided with the distribution.
00015 // 
00016 //  3. The name of the authors may not be used to endorse or promote
00017 //     products derived from this software without specific prior written
00018 //     permission.
00019 // 
00020 // THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
00021 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00022 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
00023 // NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00024 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
00025 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
00026 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
00027 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
00028 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00029 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00030 // 
00031 // This file is part of the PLearn library. For more information on the PLearn
00032 // library, go to the PLearn Web site at www.plearn.org
00033 
00034 #include "byte_order.h"
00035 
00036 namespace PLearn {
00037 using namespace std;
00038 
00039 // *** LITTLE-ENDIAN / BIG-ENDIAN HELL... ***
00040 
00041 // Functions to swap representation in memory
00042 
00043 void endianswap2(void* ptr, int n)
00044 {
00045     char *mptr = (char *) ptr;
00046     char tmp;
00047     while(n--)
00048     {
00049         tmp = mptr[0]; mptr[0]=mptr[1]; mptr[1]=tmp;
00050         mptr+=2;
00051     }
00052 }
00053 
00054 void endianswap4(void* ptr, int n)
00055 {
00056     char *mptr = (char *) ptr;
00057     char tmp;
00058     while(n--)
00059     {
00060         tmp = mptr[0]; mptr[0]=mptr[3]; mptr[3]=tmp;
00061         tmp = mptr[1]; mptr[1]=mptr[2]; mptr[2]=tmp;
00062         mptr+=4;
00063     }
00064 }
00065 
00066 void endianswap8(void* ptr, int n)
00067 {
00068     char *mptr = (char *) ptr;
00069     char tmp;
00070     while(n--)
00071     {
00072         tmp = mptr[0]; mptr[0]=mptr[7]; mptr[7]=tmp;
00073         tmp = mptr[1]; mptr[1]=mptr[6]; mptr[6]=tmp;
00074         tmp = mptr[2]; mptr[2]=mptr[5]; mptr[5]=tmp;
00075         tmp = mptr[3]; mptr[3]=mptr[4]; mptr[4]=tmp;
00076         mptr+=8;
00077     }
00078 }
00079 
00080 
00081 }
00082 
00083 
00084 /*
00085   Local Variables:
00086   mode:c++
00087   c-basic-offset:4
00088   c-file-style:"stroustrup"
00089   c-file-offsets:((innamespace . 0)(inline-open . 0))
00090   indent-tabs-mode:nil
00091   fill-column:79
00092   End:
00093 */
00094 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
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