kolibrios-gitea/programs/develop/open watcom/trunk/clib/memory/fmemmove.c

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/****************************************************************************
*
* Open Watcom Project
*
* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
* ========================================================================
*
* This file contains Original Code and/or Modifications of Original
* Code as defined in and that are subject to the Sybase Open Watcom
* Public License version 1.0 (the 'License'). You may not use this file
* except in compliance with the License. BY USING THIS FILE YOU AGREE TO
* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
* provided with the Original Code and Modifications, and is also
* available at www.sybase.com/developer/opensource.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
* NON-INFRINGEMENT. Please see the License for the specific language
* governing rights and limitations under the License.
*
* ========================================================================
*
* Description: WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE
* DESCRIBE IT HERE!
*
****************************************************************************/
#include "variety.h"
#include <stddef.h>
#include <string.h>
#if defined(__386__)
#if defined(__FLAT__)
extern void movefwd( char _WCFAR *dst, const char _WCFAR *src, unsigned len);
#pragma aux movefwd = \
0x06 /* push es */\
0x8e 0xc2 /* mov es,dx */\
0x1e /* push ds */\
0x96 /* xchg esi,eax */\
0x8e 0xd8 /* mov ds,ax */\
0xd1 0xe9 /* shr cx,1 */\
0x66 0xf3 0xa5 /* rep movsw */\
0x11 0xc9 /* adc cx,cx */\
0xf3 0xa4 /* rep movsb */\
0x1f /* pop ds */\
0x07 /* pop es */\
parm [dx edi] [si eax] [ecx] \
modify exact [edi esi ecx eax];
#else
extern void movefwd( char _WCFAR *dst, const char _WCFAR *src, unsigned len);
#pragma aux movefwd = \
0x1e /* push ds */\
0x96 /* xchg esi,eax */\
0x8e 0xd8 /* mov ds,ax */\
0xd1 0xe9 /* shr cx,1 */\
0x66 0xf3 0xa5 /* rep movsw */\
0x11 0xc9 /* adc cx,cx */\
0xf3 0xa4 /* rep movsb */\
0x1f /* pop ds */\
parm [es edi] [si eax] [ecx] \
modify exact [edi esi ecx eax];
#endif
#elif defined(M_I86)
#if defined(__SMALL_DATA__)
extern void movebwd( char _WCFAR *dst, const char _WCFAR *src, unsigned len);
#pragma aux movebwd = \
0xfd /* std */\
0x1e /* push ds */\
0x96 /* xchg si,ax */\
0x8e 0xd8 /* mov ds,ax */\
0x4e /* dec si */\
0x4f /* dec di */\
0xd1 0xe9 /* shr cx,1 */\
0xf3 0xa5 /* rep movsw */\
0x11 0xc9 /* adc cx,cx */\
0x46 /* inc si */\
0x47 /* inc di */\
0xf3 0xa4 /* rep movsb */\
0xfc /* cld */\
0x1f /* pop ds */\
parm [es di] [si ax] [cx] \
modify exact [di si cx ax];
extern void movefwd( char _WCFAR *dst, const char _WCFAR *src, unsigned len);
#pragma aux movefwd = \
0x1e /* push ds */\
0x96 /* xchg si,ax */\
0x8e 0xd8 /* mov ds,ax */\
0xd1 0xe9 /* shr cx,1 */\
0xf3 0xa5 /* rep movsw */\
0x11 0xc9 /* adc cx,cx */\
0xf3 0xa4 /* rep movsb */\
0x1f /* pop ds */\
parm [es di] [si ax] [cx] \
modify exact [di si cx ax];
#else
extern void movebwd( char _WCFAR *dst, const char _WCFAR *src, unsigned len);
#pragma aux movebwd = \
0xfd /* std */\
0x1e /* push ds */\
0x96 /* xchg si,ax */\
0x8e 0xd8 /* mov ds,ax */\
0x4e /* dec si */\
0x4f /* dec di */\
0xd1 0xe9 /* shr cx,1 */\
0xf3 0xa5 /* rep movsw */\
0x11 0xc9 /* adc cx,cx */\
0x46 /* inc si */\
0x47 /* inc di */\
0xf3 0xa4 /* rep movsb */\
0xfc /* cld */\
0x1f /* pop ds */\
parm [es di] [si ax] [cx] \
modify exact [di si cx ax];
extern void movefwd( char _WCFAR *dst, const char _WCFAR *src, unsigned len);
#pragma aux movefwd = \
0x1e /* push ds */\
0x96 /* xchg si,ax */\
0x8e 0xd8 /* mov ds,ax */\
0xd1 0xe9 /* shr cx,1 */\
0xf3 0xa5 /* rep movsw */\
0x11 0xc9 /* adc cx,cx */\
0xf3 0xa4 /* rep movsb */\
0x1f /* pop ds */\
parm [es di] [si ax] [cx] \
modify exact [di si cx ax];
#endif
#else
#error platform not supported
#endif
_WCRTLINK void _WCFAR *_fmemmove( void _WCFAR *t, const void _WCFAR *f, size_t len )
{
char _WCFAR *to = t;
const char _WCFAR *from = f;
if( from == to ) {
return( to );
}
if( from < to && from + len > to ) { /* if buffers are overlapped*/
#if defined(__HUGE__) || defined(__386__)
to += len;
from += len;
while( len != 0 ) {
to--;
from--;
*to = *from;
len--;
}
#else
movebwd(( to + len ) - 1, ( from + len ) - 1, len );
#endif
} else {
movefwd( to, from, len );
}
return( to );
}