95 lines
2.1 KiB
C
95 lines
2.1 KiB
C
|
/***
|
||
|
|
*memcmp.c - compare two blocks of memory
|
||
|
|
*
|
||
|
|
* Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved.
|
||
|
|
*
|
||
|
|
*Purpose:
|
||
|
|
* defines memcmp() - compare two memory blocks lexically and
|
||
|
|
* find their order.
|
||
|
|
*
|
||
|
|
*Revision History:
|
||
|
|
* 05-31-89 JCR C version created.
|
||
|
|
* 02-27-90 GJF Fixed calling type, #include <cruntime.h>, fixed
|
||
|
|
* copyright.
|
||
|
|
* 10-01-90 GJF New-style function declarator. Also, rewrote expr. to
|
||
|
|
* avoid using cast as an lvalue.
|
||
|
|
* 04-01-91 SRW Add #pragma function for i386 _WIN32_ and _CRUISER_
|
||
|
|
* builds
|
||
|
|
* 10-11-91 GJF Bug fix! Comparison of final bytes must use unsigned
|
||
|
|
* chars.
|
||
|
|
* 09-01-93 GJF Replaced _CALLTYPE1 with __cdecl.
|
||
|
|
* 12-03-93 GJF Turn on #pragma function for all MS front-ends (esp.,
|
||
|
|
* Alpha compiler).
|
||
|
|
*
|
||
|
|
*******************************************************************************/
|
||
|
|
|
||
|
|
#include <cruntime.h>
|
||
|
|
#include <string.h>
|
||
|
|
|
||
|
|
#ifdef _MSC_VER
|
||
|
|
#pragma function(memcmp)
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/***
|
||
|
|
*int memcmp(buf1, buf2, count) - compare memory for lexical order
|
||
|
|
*
|
||
|
|
*Purpose:
|
||
|
|
* Compares count bytes of memory starting at buf1 and buf2
|
||
|
|
* and find if equal or which one is first in lexical order.
|
||
|
|
*
|
||
|
|
*Entry:
|
||
|
|
* void *buf1, *buf2 - pointers to memory sections to compare
|
||
|
|
* size_t count - length of sections to compare
|
||
|
|
*
|
||
|
|
*Exit:
|
||
|
|
* returns < 0 if buf1 < buf2
|
||
|
|
* returns 0 if buf1 == buf2
|
||
|
|
* returns > 0 if buf1 > buf2
|
||
|
|
*
|
||
|
|
*Exceptions:
|
||
|
|
*
|
||
|
|
*******************************************************************************/
|
||
|
|
|
||
|
|
int __cdecl memcmp (
|
||
|
|
const void * buf1,
|
||
|
|
const void * buf2,
|
||
|
|
size_t count
|
||
|
|
)
|
||
|
|
{
|
||
|
|
if (!count)
|
||
|
|
return(0);
|
||
|
|
|
||
|
|
#if defined(_M_AMD64)
|
||
|
|
|
||
|
|
{
|
||
|
|
|
||
|
|
#if !defined(LIBCNTPR)
|
||
|
|
|
||
|
|
__declspec(dllimport)
|
||
|
|
|
||
|
|
#endif
|
||
|
|
|
||
|
|
size_t RtlCompareMemory( const void * src1, const void * src2, size_t length );
|
||
|
|
|
||
|
|
size_t length;
|
||
|
|
|
||
|
|
if ( ( length = RtlCompareMemory( buf1, buf2, count ) ) == count ) {
|
||
|
|
return(0);
|
||
|
|
}
|
||
|
|
|
||
|
|
buf1 = (char *)buf1 + length;
|
||
|
|
buf2 = (char *)buf2 + length;
|
||
|
|
}
|
||
|
|
|
||
|
|
#else
|
||
|
|
|
||
|
|
while ( --count && *(char *)buf1 == *(char *)buf2 ) {
|
||
|
|
buf1 = (char *)buf1 + 1;
|
||
|
|
buf2 = (char *)buf2 + 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
#endif
|
||
|
|
|
||
|
|
return( *((unsigned char *)buf1) - *((unsigned char *)buf2) );
|
||
|
|
}
|