swab.c revision 102639
11573Srgrimes/* 21573Srgrimes * Copyright (c) 1988, 1993 31573Srgrimes * The Regents of the University of California. All rights reserved. 41573Srgrimes * 51573Srgrimes * This code is derived from software contributed to Berkeley by 61573Srgrimes * Jeffrey Mogul. 71573Srgrimes * 81573Srgrimes * Redistribution and use in source and binary forms, with or without 91573Srgrimes * modification, are permitted provided that the following conditions 101573Srgrimes * are met: 111573Srgrimes * 1. Redistributions of source code must retain the above copyright 121573Srgrimes * notice, this list of conditions and the following disclaimer. 131573Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 141573Srgrimes * notice, this list of conditions and the following disclaimer in the 151573Srgrimes * documentation and/or other materials provided with the distribution. 161573Srgrimes * 3. All advertising materials mentioning features or use of this software 171573Srgrimes * must display the following acknowledgement: 181573Srgrimes * This product includes software developed by the University of 191573Srgrimes * California, Berkeley and its contributors. 201573Srgrimes * 4. Neither the name of the University nor the names of its contributors 211573Srgrimes * may be used to endorse or promote products derived from this software 221573Srgrimes * without specific prior written permission. 231573Srgrimes * 241573Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 251573Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 261573Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 271573Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 281573Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 291573Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 301573Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 311573Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 321573Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 331573Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 341573Srgrimes * SUCH DAMAGE. 351573Srgrimes */ 361573Srgrimes 371573Srgrimes#if defined(LIBC_SCCS) && !defined(lint) 381573Srgrimesstatic char sccsid[] = "@(#)swab.c 8.1 (Berkeley) 6/4/93"; 391573Srgrimes#endif /* LIBC_SCCS and not lint */ 4086170Sobrien#include <sys/cdefs.h> 4186170Sobrien__FBSDID("$FreeBSD: head/lib/libc/string/swab.c 102639 2002-08-30 20:33:05Z robert $"); 421573Srgrimes 431573Srgrimes#include <string.h> 441573Srgrimes 451573Srgrimesvoid 46102639Srobertswab(const void * __restrict from, void * __restrict to, size_t len) 471573Srgrimes{ 4892889Sobrien unsigned long temp; 4992889Sobrien int n; 5092889Sobrien char *fp, *tp; 511573Srgrimes 52102639Srobert n = len >> 1; 531573Srgrimes fp = (char *)from; 541573Srgrimes tp = (char *)to; 551573Srgrimes#define STEP temp = *fp++,*tp++ = *fp++,*tp++ = temp 561573Srgrimes /* round to multiple of 8 */ 57102639Srobert for (; n & 0x7; --n) 581573Srgrimes STEP; 59102639Srobert for (n >>= 3; n > 0; --n) { 601573Srgrimes STEP; STEP; STEP; STEP; 611573Srgrimes STEP; STEP; STEP; STEP; 621573Srgrimes } 631573Srgrimes} 64