projects / apple / libc.git / blame
| Commit | Line | Data |
|---|---|---|
| 9385eb3d A |
1 | /* |
| 2 | * Copyright (c) 1988, 1993 | |
| e9ce8d39 A |
3 | * The Regents of the University of California. All rights reserved. |
| 4 | * | |
| 5 | * This code is derived from software contributed to Berkeley by | |
| 9385eb3d | 6 | * Jeffrey Mogul. |
| e9ce8d39 A |
7 | * |
| 8 | * Redistribution and use in source and binary forms, with or without | |
| 9 | * modification, are permitted provided that the following conditions | |
| 10 | * are met: | |
| 11 | * 1. Redistributions of source code must retain the above copyright | |
| 12 | * notice, this list of conditions and the following disclaimer. | |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright | |
| 14 | * notice, this list of conditions and the following disclaimer in the | |
| 15 | * documentation and/or other materials provided with the distribution. | |
| e9ce8d39 A |
16 | * 4. Neither the name of the University nor the names of its contributors |
| 17 | * may be used to endorse or promote products derived from this software | |
| 18 | * without specific prior written permission. | |
| 19 | * | |
| 20 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
| 21 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 22 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 23 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
| 24 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 25 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
| 26 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 27 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 28 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 29 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 30 | * SUCH DAMAGE. | |
| 31 | */ | |
| 32 | ||
| 33 | #if defined(LIBC_SCCS) && !defined(lint) | |
| 9385eb3d | 34 | static char sccsid[] = "@(#)swab.c 8.1 (Berkeley) 6/4/93"; |
| e9ce8d39 | 35 | #endif /* LIBC_SCCS and not lint */ |
| 9385eb3d | 36 | #include <sys/cdefs.h> |
| 1f2f436a | 37 | __FBSDID("$FreeBSD: src/lib/libc/string/swab.c,v 1.7 2007/01/09 00:28:12 imp Exp $"); |
| e9ce8d39 | 38 | |
| 1f2f436a | 39 | #include <unistd.h> |
| e9ce8d39 | 40 | |
| 9385eb3d | 41 | void |
| 1f2f436a | 42 | swab(const void * __restrict from, void * __restrict to, ssize_t len) |
| e9ce8d39 | 43 | { |
| 9385eb3d A |
44 | unsigned long temp; |
| 45 | int n; | |
| 46 | char *fp, *tp; | |
| 5b2abdfb | 47 | |
| ad3c9f2a A |
48 | if (len <= 0) |
| 49 | return; | |
| 9385eb3d A |
50 | n = len >> 1; |
| 51 | fp = (char *)from; | |
| 52 | tp = (char *)to; | |
| 53 | #define STEP temp = *fp++,*tp++ = *fp++,*tp++ = temp | |
| 54 | /* round to multiple of 8 */ | |
| 55 | for (; n & 0x7; --n) | |
| 56 | STEP; | |
| 57 | for (n >>= 3; n > 0; --n) { | |
| 58 | STEP; STEP; STEP; STEP; | |
| 59 | STEP; STEP; STEP; STEP; | |
| 60 | } | |
| e9ce8d39 | 61 | } |