endian.h revision 140425 
1/*-
2 * Copyright (c) 2001 David E. O'Brien
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 * 3. Neither the name of the University nor the names of its contributors
13 *    may be used to endorse or promote products derived from this software
14 *    without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 *	@(#)endian.h	8.1 (Berkeley) 6/10/93
29 * $NetBSD: endian.h,v 1.7 1999/08/21 05:53:51 simonb Exp $
30 * $FreeBSD: head/sys/arm/include/endian.h 140425 2005-01-18 15:51:50Z cognet $
31 */
32
33#ifndef _ENDIAN_H_
34#define	_ENDIAN_H_
35
36#include <sys/_types.h>
37
38/*
39 * Definitions for byte order, according to byte significance from low
40 * address to high.
41 */
42#define _LITTLE_ENDIAN  1234    /* LSB first: i386, vax */
43#define _BIG_ENDIAN     4321    /* MSB first: 68000, ibm, net */
44#define _PDP_ENDIAN     3412    /* LSB first in word, MSW first in long */
45
46#ifdef __ARMEB__
47#define _BYTE_ORDER	_BIG_ENDIAN
48#else
49#define	_BYTE_ORDER	_LITTLE_ENDIAN
50#endif /* __ARMEB__ */
51
52#if __BSD_VISIBLE
53#define LITTLE_ENDIAN   _LITTLE_ENDIAN
54#define BIG_ENDIAN      _BIG_ENDIAN
55#define PDP_ENDIAN      _PDP_ENDIAN
56#define BYTE_ORDER      _BYTE_ORDER
57#endif
58
59#ifdef __ARMEB__
60#define _QUAD_HIGHWORD 0
61#define _QUAD_LOWWORD 1
62#define __ntohl(x)	((__uint32_t)(x))
63#define __ntohs(x)	((__uint16_t)(x))
64#define __htonl(x)	((__uint32_t)(x))
65#define __htons(x)	((__uint16_t)(x))
66#else
67#define _QUAD_HIGHWORD  1
68#define _QUAD_LOWWORD 0
69#define __ntohl(x)        (__bswap32(x))
70#define __ntohs(x)        (__bswap16(x))
71#define __htonl(x)        (__bswap32(x))
72#define __htons(x)        (__bswap16(x))
73#endif /* __ARMEB__ */
74
75static __inline __uint64_t
76__bswap64(__uint64_t _x)
77{
78
79	return ((_x >> 56) | ((_x >> 40) & 0xff00) | ((_x >> 24) & 0xff0000) |
80	    ((_x >> 8) & 0xff000000) | ((_x << 8) & ((__uint64_t)0xff << 32)) |
81	    ((_x << 24) & ((__uint64_t)0xff << 40)) |
82	    ((_x << 40) & ((__uint64_t)0xff << 48)) | ((_x << 56)));
83}
84
85static __inline __uint32_t
86__bswap32_var(__uint32_t v)
87{
88	__uint32_t t1;
89
90	t1 = v ^ ((v << 16) | (v >> 16));
91	t1 &= 0xff00ffffU;
92	v = (v >> 8) | (v << 24);
93	v ^= (t1 >> 8);
94
95	return (v);
96 }
97
98static __inline __uint16_t
99__bswap16_var(__uint32_t v)
100{
101	__asm __volatile(
102	    "mov    %0, %1, ror #8\n"
103	    "orr    %0, %0, %0, lsr #16\n"
104	    "bic    %0, %0, %0, lsl #16"
105	    : "=r" (v)
106	    : "0" (v));
107
108	return (v);
109}
110
111#ifdef __OPTIMIZE__
112
113#define __bswap32_constant(x)	\
114    ((((x) & 0xff000000U) >> 24) |	\
115     (((x) & 0x00ff0000U) >>  8) |	\
116     (((x) & 0x0000ff00U) <<  8) |	\
117     (((x) & 0x000000ffU) << 24))
118
119#define __bswap16_constant(x)	\
120    ((((x) & 0xff00) >> 8) |		\
121     (((x) & 0x00ff) << 8))
122
123#define __bswap16(x)	\
124    ((__uint16_t)(__builtin_constant_p(x) ?	\
125     __bswap16_constant(x) :			\
126     __bswap16_var(x)))
127
128#define __bswap32(x)	\
129    ((__uint32_t)(__builtin_constant_p(x) ? 	\
130     __bswap32_constant(x) :			\
131     __bswap32_var(x)))
132
133#else
134#define __bswap16(x)	__bswap16_var(x)
135#define __bswap32(x)	__bswap32_var(x)
136
137#endif /* __OPTIMIZE__ */
138#endif /* !_ENDIAN_H_ */
139