byte_swap_4.S revision 1.5 1 /* $NetBSD: byte_swap_4.S,v 1.5 2012/11/27 23:57:07 matt Exp $ */
2
3 /*-
4 * Copyright (c) 1997 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Neil A. Carson
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <machine/asm.h>
33
34 #if defined(_KERNEL) || defined(_STANDALONE)
35 _ENTRY(_C_LABEL(bswap32))
36 #else
37 _ENTRY(_C_LABEL(__bswap32))
38 #endif
39 #if BYTE_ORDER == LITTLE_ENDIAN
40 _ENTRY(_C_LABEL(ntohl))
41 _ENTRY(_C_LABEL(htonl))
42 #endif
43 _PROF_PROLOGUE
44 #ifdef _ARM_ARCH_6
45 rev r0, r0
46 #else
47 eor r1, r0, r0, ror #16
48 bic r1, r1, #0x00FF0000
49 mov r0, r0, ror #8
50 eor r0, r0, r1, lsr #8
51 #endif
52 RET
53