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/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 1997-2009. All Rights Reserved.
*
* The contents of this file are subject to the Erlang Public License,
* Version 1.1, (the "License"); you may not use this file except in
* compliance with the License. You should have received a copy of the
* Erlang Public License along with this software. If not, it can be
* retrieved online at http://www.erlang.org/.
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* %CopyrightEnd%
*/
/*
* This memmove assumes that both src and dst are aligned on an address
* divisible by 4 and that n is a multiple of four.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifndef HAVE_MEMMOVE
#define MEMCPY_LIMIT 12
typedef unsigned long u_long;
typedef unsigned short u_short;
static void copy_high(dst, src, n)
char* dst; char* src; int n;
{
dst += n;
src += n;
if (n >= MEMCPY_LIMIT) {
while(((u_long) dst) & 3) {
*--dst = *--src;
n--;
}
if ((((u_long) src) & 3) == 0) {
while(n >= sizeof(u_long)) {
src -= sizeof(u_long);
dst -= sizeof(u_long);
*((u_long*)dst) = *((u_long*)src);
n -= sizeof(u_long);
}
}
else if ((((u_short) src) & 3) == 2) {
while(n >= sizeof(u_short)) {
src -= sizeof(u_short);
dst -= sizeof(u_short);
*((u_short*)dst) = *((u_short*)src);
n -= sizeof(u_short);
}
}
}
while(n > 0) {
*--dst = *--src;
n--;
}
}
static void copy_low(dst, src, n)
char* dst; char* src; int n;
{
if (n >= MEMCPY_LIMIT) {
while(((u_long) dst) & 3) {
*dst++ = *src++;
n--;
}
if ((((u_long) src) & 3) == 0) {
while(n >= sizeof(u_long)) {
*((u_long*)dst) = *((u_long*)src);
src += sizeof(u_long);
dst += sizeof(u_long);
n -= sizeof(u_long);
}
}
else if ((((u_long) src) & 3) == 2) {
while(n >= sizeof(u_short)) {
*((u_short*)dst) = *((u_short*)src);
src += sizeof(u_short);
dst += sizeof(u_short);
n -= sizeof(u_short);
}
}
}
while(n > 0) {
*dst++ = *src++;
n--;
}
}
/*
** Move memory (with overlap)
*/
void* memmove(dst, src, n)
char* dst; char* src; int n;
{
if (dst < src)
copy_low(dst, src, n);
else if (dst > src)
copy_high(dst, src, n);
return dst;
}
#endif /* HAVE_MEMMOVE */
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