/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 1988, 2011, Oracle and/or its affiliates. All rights reserved.
*/
/* Copyright (c) 1988 AT&T */
/* All Rights Reserved */
/*
* Swab bytes
*/
#include "lint.h"
#include <sys/types.h>
#include <unistd.h>
#define STEP (void)((temp = *from++), (*to++ = *from++), (*to++ = temp))
void
swab_impl(const char *from, char *to, ssize_t n)
{
char temp;
if (n <= 1)
return;
n >>= 1; n++;
/* round to multiple of 8 */
while ((--n) & 07)
STEP;
n >>= 3;
while (--n >= 0) {
STEP; STEP; STEP; STEP;
STEP; STEP; STEP; STEP;
}
}
/*
* Breaking this code into two parts, swab() and swab_impl(),
* enables us to preserve historical behavior even in the
* face of the 'restrict' keyword, namely that if src and dest
* point to the same location, bytes are swapped in place.
*/
#pragma weak _swab = swab
void
swab(const void *_RESTRICT_KYWD src, void *_RESTRICT_KYWD dest, ssize_t n)
{
swab_impl((const char *)src, (char *)dest, n);
}