swab.c revision 1573
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 */ 401573Srgrimes 411573Srgrimes#include <string.h> 421573Srgrimes 431573Srgrimesvoid 441573Srgrimesswab(from, to, len) 451573Srgrimes const void *from; 461573Srgrimes void *to; 471573Srgrimes size_t len; 481573Srgrimes{ 491573Srgrimes register unsigned long temp; 501573Srgrimes register int n; 511573Srgrimes register char *fp, *tp; 521573Srgrimes 531573Srgrimes n = (len >> 1) + 1; 541573Srgrimes fp = (char *)from; 551573Srgrimes tp = (char *)to; 561573Srgrimes#define STEP temp = *fp++,*tp++ = *fp++,*tp++ = temp 571573Srgrimes /* round to multiple of 8 */ 581573Srgrimes while ((--n) & 07) 591573Srgrimes STEP; 601573Srgrimes n >>= 3; 611573Srgrimes while (--n >= 0) { 621573Srgrimes STEP; STEP; STEP; STEP; 631573Srgrimes STEP; STEP; STEP; STEP; 641573Srgrimes } 651573Srgrimes} 66