xref: /minix3/common/lib/libc/arch/arm/gen/byte_swap_4.S (revision 84d9c625bfea59e274550651111ae9edfdc40fbd)
1*84d9c625SLionel Sambuc/*	$NetBSD: byte_swap_4.S,v 1.7 2013/08/19 03:44:47 matt Exp $	*/
2b6cbf720SGianluca Guida
3b6cbf720SGianluca Guida/*-
4b6cbf720SGianluca Guida * Copyright (c) 1997 The NetBSD Foundation, Inc.
5b6cbf720SGianluca Guida * All rights reserved.
6b6cbf720SGianluca Guida *
7b6cbf720SGianluca Guida * This code is derived from software contributed to The NetBSD Foundation
8b6cbf720SGianluca Guida * by Neil A. Carson
9b6cbf720SGianluca Guida *
10b6cbf720SGianluca Guida * Redistribution and use in source and binary forms, with or without
11b6cbf720SGianluca Guida * modification, are permitted provided that the following conditions
12b6cbf720SGianluca Guida * are met:
13b6cbf720SGianluca Guida * 1. Redistributions of source code must retain the above copyright
14b6cbf720SGianluca Guida *    notice, this list of conditions and the following disclaimer.
15b6cbf720SGianluca Guida * 2. Redistributions in binary form must reproduce the above copyright
16b6cbf720SGianluca Guida *    notice, this list of conditions and the following disclaimer in the
17b6cbf720SGianluca Guida *    documentation and/or other materials provided with the distribution.
18b6cbf720SGianluca Guida *
19b6cbf720SGianluca Guida * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20b6cbf720SGianluca Guida * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21b6cbf720SGianluca Guida * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22b6cbf720SGianluca Guida * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23b6cbf720SGianluca Guida * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24b6cbf720SGianluca Guida * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25b6cbf720SGianluca Guida * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26b6cbf720SGianluca Guida * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27b6cbf720SGianluca Guida * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28b6cbf720SGianluca Guida * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29b6cbf720SGianluca Guida * POSSIBILITY OF SUCH DAMAGE.
30b6cbf720SGianluca Guida */
31b6cbf720SGianluca Guida
32b6cbf720SGianluca Guida#include <machine/asm.h>
33b6cbf720SGianluca Guida
34b6cbf720SGianluca Guida#if defined(_KERNEL) || defined(_STANDALONE)
35*84d9c625SLionel Sambuc#define	FUNC	_C_LABEL(bswap32)
36b6cbf720SGianluca Guida#else
37*84d9c625SLionel Sambuc#define	FUNC	_C_LABEL(__bswap32)
38b6cbf720SGianluca Guida#endif
39*84d9c625SLionel SambucENTRY(FUNC)
40*84d9c625SLionel Sambuc#ifdef _ARM_ARCH_6
41*84d9c625SLionel Sambuc	rev	r0, r0
42*84d9c625SLionel Sambuc#elif !defined(__thumb__)
43*84d9c625SLionel Sambuc	eor	r1, r0, r0, ror #16	/* 4.3.2.1 -> 42.31.42.31 */
44*84d9c625SLionel Sambuc	bic	r1, r1, #0x00FF0000	/* 42.31.42.31 -> 42.0.42.31 */
45*84d9c625SLionel Sambuc	mov	r0, r0, ror #8		/* 4.3.2.1 -> 1.4.3.2 */
46*84d9c625SLionel Sambuc	eor	r0, r0, r1, lsr #8	/* 1.4.3.2 ^ 0.42.0.42 -> 1.2.3.4 */
47*84d9c625SLionel Sambuc#else
48*84d9c625SLionel Sambuc	movs	r3, #16
49*84d9c625SLionel Sambuc	lsls	r1, r0, #8		/* 4.3.2.1 -> 3.2.1.0 /*
50*84d9c625SLionel Sambuc	lsrs	r0, r0, #8		/* 4.3.2.1 -> 0.4.3.2 */
51*84d9c625SLionel Sambuc	rors	r1, r3			/* 3.2.1.0 -> 1.0.3.2 */
52*84d9c625SLionel Sambuc	rors	r0, r3			/* 0.4.3.2 -> 3.2.0.4 */
53*84d9c625SLionel Sambuc	lsrs	r1, r1, #8		/* 1.0.3.2 -> 0.1.0.3 */
54*84d9c625SLionel Sambuc	lsls	r1, r1, #8		/* 0.1.0.3 -> 1.0.3.0 */
55*84d9c625SLionel Sambuc	lsls	r0, r0, #8		/* 3.2.0.4 -> 2.0.4.0 */
56*84d9c625SLionel Sambuc	lsrs	r0, r0, #8		/* 2.0.4.0 -> 0.2.0.4 */
57*84d9c625SLionel Sambuc	orrs	r0, r0, r1		/* 1.0.3.0 | 0.2.0.4 -> 1.2.3.4 */
58b6cbf720SGianluca Guida#endif
59b6cbf720SGianluca Guida	RET
60*84d9c625SLionel SambucEND(FUNC)
61*84d9c625SLionel Sambuc
62*84d9c625SLionel Sambuc#if BYTE_ORDER == LITTLE_ENDIAN
63*84d9c625SLionel SambucSTRONG_ALIAS(_C_LABEL(ntohl), FUNC)
64*84d9c625SLionel SambucSTRONG_ALIAS(_C_LABEL(htonl), FUNC)
65*84d9c625SLionel Sambuc#endif
66