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/* $Revision: 1.3 $
**
** This file has been modified to get it to compile more easily
** on pre-4.4BSD systems. Rich $alz, June 1991.
*/
#include "defs.h"
#if USE_MEMMOVE
#define const /* NULL */
#define void char
#define size_t int
#define NULL 0
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms are permitted provided
* that: (1) source distributions retain this entire copyright notice and
* comment, and (2) distributions including binaries display the following
* acknowledgement: ``This product includes software developed by the
* University of California, Berkeley and its contributors'' in the
* documentation or other materials provided with the distribution and in
* all advertising materials mentioning features or use of this software.
* Neither the name of the University nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#if 0
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)bcopy.c 5.8 (Berkeley) 6/23/90";
#endif /* LIBC_SCCS and not lint */
#include <sys/stdc.h>
#include <string.h>
#endif
/*
* sizeof(word) MUST BE A POWER OF TWO
* SO THAT wmask BELOW IS ALL ONES
*/
typedef int word; /* "word" used for optimal copy speed */
#define wsize sizeof(word)
#define wmask (wsize - 1)
/*
* Copy a block of memory, handling overlap.
* This is the routine that actually implements
* (the portable versions of) bcopy, memcpy, and memmove.
*/
#ifdef USE_MEMCOPY
void *
memcpy(char *dst0, const char *src0, size_t length)
#else
#ifdef USE_MEMMOVE
void *
memmove(char *dst0, const char *src0, size_t length)
#else
void
bcopy(const char *src0, char *dst0, size_t length)
#endif
#endif
{
register char *dst = dst0;
register const char *src = src0;
register size_t t;
if (length == 0 || dst == src) /* nothing to do */
goto retval;
/*
* Macros: loop-t-times; and loop-t-times, t>0
*/
#define TLOOP(s) if (t) TLOOP1(s)
#define TLOOP1(s) do { s; } while (--t)
if ((char *)dst < (char *)src) {
/*
* Copy forward.
*/
t = (int)src; /* only need low bits */
if ((t | (int)dst) & wmask) {
/*
* Try to align operands. This cannot be done
* unless the low bits match.
*/
if ((t ^ (int)dst) & wmask || length < wsize)
t = length;
else
t = wsize - (t & wmask);
length -= t;
TLOOP1(*dst++ = *src++);
}
/*
* Copy whole words, then mop up any trailing bytes.
*/
t = length / wsize;
TLOOP(*(word *)dst = *(word *)src; src += wsize; dst += wsize);
t = length & wmask;
TLOOP(*dst++ = *src++);
} else {
/*
* Copy backwards. Otherwise essentially the same.
* Alignment works as before, except that it takes
* (t&wmask) bytes to align, not wsize-(t&wmask).
*/
src += length;
dst += length;
t = (int)src;
if ((t | (int)dst) & wmask) {
if ((t ^ (int)dst) & wmask || length <= wsize)
t = length;
else
t &= wmask;
length -= t;
TLOOP1(*--dst = *--src);
}
t = length / wsize;
TLOOP(src -= wsize; dst -= wsize; *(word *)dst = *(word *)src);
t = length & wmask;
TLOOP(*--dst = *--src);
}
retval:
#ifdef USE_MEMCOPY
return(dst0);
#else
#ifdef USE_MEMMOVE
return(dst0);
#else
return;
#endif
#endif
}
#endif
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