xref: /freebsd/sys/riscv/include/endian.h (revision 7447ca0eb235974642312b9555caec00b57d8fc1)
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  * $FreeBSD$
31  */
32 
33 #ifndef _MACHINE_ENDIAN_H_
34 #define	_MACHINE_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 #define	_BYTE_ORDER	_LITTLE_ENDIAN
47 
48 #if __BSD_VISIBLE
49 #define	LITTLE_ENDIAN   _LITTLE_ENDIAN
50 #define	BIG_ENDIAN      _BIG_ENDIAN
51 #define	PDP_ENDIAN      _PDP_ENDIAN
52 #define	BYTE_ORDER      _BYTE_ORDER
53 #endif
54 
55 #define	_QUAD_HIGHWORD  1
56 #define	_QUAD_LOWWORD 0
57 #define	__ntohl(x)        (__bswap32(x))
58 #define	__ntohs(x)        (__bswap16(x))
59 #define	__htonl(x)        (__bswap32(x))
60 #define	__htons(x)        (__bswap16(x))
61 
62 static __inline __uint64_t
63 __bswap64(__uint64_t _x)
64 {
65 	__uint64_t ret;
66 
67 	ret = (_x >> 56);
68 	ret |= ((_x >> 40) & 0xff00);
69 	ret |= ((_x >> 24) & 0xff0000);
70 	ret |= ((_x >>  8) & 0xff000000);
71 	ret |= ((_x <<  8) & ((__uint64_t)0xff << 32));
72 	ret |= ((_x << 24) & ((__uint64_t)0xff << 40));
73 	ret |= ((_x << 40) & ((__uint64_t)0xff << 48));
74 	ret |= (_x << 56);
75 
76 	return (ret);
77 }
78 
79 static __inline __uint32_t
80 __bswap32_var(__uint32_t _x)
81 {
82 
83 	return ((_x >> 24) | ((_x >> 8) & 0xff00) | ((_x << 8) & 0xff0000) |
84 	    ((_x << 24) & 0xff000000));
85 }
86 
87 static __inline __uint16_t
88 __bswap16_var(__uint16_t _x)
89 {
90 	__uint32_t ret;
91 
92 	ret = ((_x >> 8) | ((_x << 8) & 0xff00));
93 
94 	return ((__uint16_t)ret);
95 }
96 
97 #ifdef __OPTIMIZE__
98 
99 #define	__bswap32_constant(x)	\
100     ((((x) & 0xff000000U) >> 24) |	\
101      (((x) & 0x00ff0000U) >>  8) |	\
102      (((x) & 0x0000ff00U) <<  8) |	\
103      (((x) & 0x000000ffU) << 24))
104 
105 #define	__bswap16_constant(x)	\
106     ((((x) & 0xff00) >> 8) |		\
107      (((x) & 0x00ff) << 8))
108 
109 #define	__bswap16(x)	\
110     ((__uint16_t)(__builtin_constant_p(x) ?	\
111      __bswap16_constant(x) :			\
112      __bswap16_var(x)))
113 
114 #define	__bswap32(x)	\
115     ((__uint32_t)(__builtin_constant_p(x) ? 	\
116      __bswap32_constant(x) :			\
117      __bswap32_var(x)))
118 
119 #else
120 #define	__bswap16(x)	__bswap16_var(x)
121 #define	__bswap32(x)	__bswap32_var(x)
122 
123 #endif /* __OPTIMIZE__ */
124 #endif /* !_MACHINE_ENDIAN_H_ */
125