You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

144 lines
4.2 KiB

/* Part of the ht://Dig package <http://www.htdig.org/> */
/* Copyright (c) 1999-2004 The ht://Dig Group */
/* For copyright details, see the file COPYING in your distribution */
/* or the GNU Library General Public License (LGPL) version 2 or later */
/* <http://www.gnu.org/copyleft/lgpl.html> */
/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996, 1997, 1998, 1999
* Sleepycat Software. All rights reserved.
*/
/*
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifdef HAVE_CONFIG_H
#include "htconfig.h"
#endif /* HAVE_CONFIG_H */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#endif
#ifndef HAVE_MEMMOVE
/*
* sizeof(word) MUST BE A POWER OF TWO
* SO THAT wmask BELOW IS ALL ONES
*/
typedef int word; /* "word" used for optimal copy speed */
#undef wsize
#define wsize sizeof(word)
#undef wmask
#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.
*/
/*
* PUBLIC: #ifndef HAVE_MEMMOVE
* PUBLIC: void *memmove __P((void *, const void *, size_t));
* PUBLIC: #endif
*/
void *
memmove(dst0, src0, length)
void *dst0;
const void *src0;
register size_t length;
{
register char *dst = dst0;
register const char *src = src0;
register size_t t;
if (length == 0 || dst == src) /* nothing to do */
goto done;
/*
* Macros: loop-t-times; and loop-t-times, t>0
*/
#undef TLOOP
#define TLOOP(s) if (t) TLOOP1(s)
#undef TLOOP1
#define TLOOP1(s) do { s; } while (--t)
if ((unsigned long)dst < (unsigned long)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);
}
done:
return (dst0);
}
#endif /* HAVE_MEMOVE */