windows-nt/Source/XPSP1/NT/base/crts/crtw32/misc/bswap.c

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2020-09-26 03:20:57 -05:00
/***
*rotl.c - rotate an unsigned integer left
*
* Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* defines _byteswap() - performs a byteswap on an unsigned integer.
*
*Revision History:
* 09-06-00 GB Module created
*
*******************************************************************************/
#include <cruntime.h>
#include <stdlib.h>
#ifdef _MSC_VER
#pragma function(_byteswap_ulong, _byteswap_uint64, _byteswap_ushort)
#endif
/***
*unsigned long _byteswap_ulong(i) - long byteswap
*
*Purpose:
* Performs a byte swap on an unsigned integer.
*
*Entry:
* unsigned long i: value to swap
*
*Exit:
* returns swaped
*
*Exceptions:
* None.
*
*******************************************************************************/
unsigned long __cdecl _byteswap_ulong(unsigned long i)
{
unsigned int j;
j = (i << 24);
j += (i << 8) & 0x00FF0000;
j += (i >> 8) & 0x0000FF00;
j += (i >> 24);
return j;
}
unsigned short __cdecl _byteswap_ushort(unsigned short i)
{
unsigned short j;
j = (i << 8) ;
j += (i >> 8) ;
return j;
}
unsigned __int64 __cdecl _byteswap_uint64(unsigned __int64 i)
{
unsigned __int64 j;
j = (i << 56);
j += (i << 40)&0x00FF000000000000;
j += (i << 24)&0x0000FF0000000000;
j += (i << 8)&0x000000FF00000000;
j += (i >> 8)&0x00000000FF000000;
j += (i >> 24)&0x0000000000FF0000;
j += (i >> 40)&0x000000000000FF00;
j += (i >> 56);
return j;
}