byte_swap.h revision 1.1 
1/*	$NetBSD: byte_swap.h,v 1.1 2002/08/13 22:41:36 thorpej Exp $	*/
2
3/*-
4 * Copyright (c) 1997, 1999, 2002 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Charles M. Hannum, Neil A. Carson, and Jason R. Thorpe.
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 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the NetBSD
21 *	Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 *    contributors may be used to endorse or promote products derived
24 *    from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39#ifndef _ARM_BYTE_SWAP_H_
40#define	_ARM_BYTE_SWAP_H_
41
42#include <sys/types.h>
43
44static __inline u_int32_t
45__byte_swap_long_variable(u_int32_t v)
46{
47	int tmp;
48
49	__asm __volatile(
50		"eor	%1, %2, %2, ror #16\n"
51		"bic	%1, %1, #0x00ff0000\n"
52		"mov	%0, %2, ror #8\n"
53		"eor	%0, %0, %1, lsr #8"
54	: "=r" (v), "=&r" (tmp)
55	: "0" (v));
56
57	return (v);
58}
59
60static __inline u_int16_t
61__byte_swap_word_variable(u_int16_t v)
62{
63
64	__asm __volatile(
65		"mov	%0, %1, ror #8\n"
66		"orr	%0, %0, %0, lsr #16\n"
67		"bic	%0, %0, %0, lsl #16"
68	: "=r" (v)
69	: "0" (v));
70
71	return (v);
72}
73
74#ifdef __OPTIMIZE__
75
76#define __byte_swap_long_constant(x)	\
77	((((x) & 0xff000000) >> 24) |	\
78	 (((x) & 0x00ff0000) >>  8) |	\
79	 (((x) & 0x0000ff00) <<  8) |	\
80	 (((x) & 0x000000ff) << 24))
81
82#define	__byte_swap_word_constant(x)	\
83	((((x) & 0xff00) >> 8) |	\
84	 (((x) & 0x00ff) << 8))
85
86#define	__byte_swap_long(x)		\
87	(__builtin_constant_p((x)) ?	\
88	 __byte_swap_long_constant(x) :	__byte_swap_long_variable(x))
89
90#define	__byte_swap_word(x)		\
91	(__builtin_constant_p((x)) ?	\
92	 __byte_swap_word_constant(x) : __byte_swap_word_variable(x))
93
94#else
95
96#define	__byte_swap_long(x)	__byte_swap_long_variable(x)
97#define	__byte_swap_word(x)	__byte_swap_word_variable(x)
98
99#endif /* __OPTIMIZE__ */
100
101#endif /* _ARM_BYTE_SWAP_H_ */
102