| /* $NetBSD: swab.c,v 1.18 2011/01/04 17:14:07 martin Exp $ */ |
| |
| /* |
| * Copyright (c) 1988, 1993 |
| * The Regents of the University of California. All rights reserved. |
| * |
| * This code is derived from software contributed to Berkeley by |
| * Jeffrey Mogul. |
| * |
| * 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. |
| */ |
| |
| #include <sys/cdefs.h> |
| #if defined(LIBC_SCCS) && !defined(lint) |
| #if 0 |
| static char sccsid[] = "@(#)swab.c 8.1 (Berkeley) 6/4/93"; |
| #else |
| __RCSID("$NetBSD: swab.c,v 1.18 2011/01/04 17:14:07 martin Exp $"); |
| #endif |
| #endif /* LIBC_SCCS and not lint */ |
| |
| #include <assert.h> |
| #include <unistd.h> |
| |
| void |
| swab(const void * __restrict from, void * __restrict to, ssize_t len) |
| { |
| char temp; |
| const char *fp; |
| char *tp; |
| |
| if (len <= 1) |
| return; |
| |
| _DIAGASSERT(from != NULL); |
| _DIAGASSERT(to != NULL); |
| |
| len /= 2; |
| fp = (const char *)from; |
| tp = (char *)to; |
| #define STEP temp = *fp++,*tp++ = *fp++,*tp++ = temp |
| |
| if (__predict_false(len == 1)) { |
| STEP; |
| return; |
| } |
| |
| /* round to multiple of 8 */ |
| while ((--len % 8) != 0) |
| STEP; |
| len /= 8; |
| if (len == 0) |
| return; |
| while (len-- != 0) { |
| STEP; STEP; STEP; STEP; |
| STEP; STEP; STEP; STEP; |
| } |
| } |