xref: /freebsd/sys/amd64/include/endian.h (revision f0adf7f5cdd241db2f2c817683191a6ef64a4e95)
1 /*-
2  * Copyright (c) 1987, 1991 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)endian.h	7.8 (Berkeley) 4/3/91
30  * $FreeBSD$
31  */
32 
33 #ifndef _MACHINE_ENDIAN_H_
34 #define	_MACHINE_ENDIAN_H_
35 
36 #include <sys/cdefs.h>
37 #include <sys/_types.h>
38 
39 /*
40  * Define the order of 32-bit words in 64-bit words.
41  */
42 #define	_QUAD_HIGHWORD 1
43 #define	_QUAD_LOWWORD 0
44 
45 /*
46  * Definitions for byte order, according to byte significance from low
47  * address to high.
48  */
49 #define	_LITTLE_ENDIAN	1234	/* LSB first: i386, vax */
50 #define	_BIG_ENDIAN	4321	/* MSB first: 68000, ibm, net */
51 #define	_PDP_ENDIAN	3412	/* LSB first in word, MSW first in long */
52 
53 #define	_BYTE_ORDER	_LITTLE_ENDIAN
54 
55 /*
56  * Deprecated variants that don't have enough underscores to be useful in more
57  * strict namespaces.
58  */
59 #if __BSD_VISIBLE
60 #define	LITTLE_ENDIAN	_LITTLE_ENDIAN
61 #define	BIG_ENDIAN	_BIG_ENDIAN
62 #define	PDP_ENDIAN	_PDP_ENDIAN
63 #define	BYTE_ORDER	_BYTE_ORDER
64 #endif
65 
66 #ifdef __GNUC__
67 
68 #define __word_swap_int_var(x) \
69 __extension__ ({ register __uint32_t __X = (x); \
70    __asm ("rorl $16, %0" : "+r" (__X)); \
71    __X; })
72 
73 #ifdef __OPTIMIZE__
74 
75 #define	__word_swap_int_const(x) \
76 	((((x) & 0xffff0000) >> 16) | \
77 	 (((x) & 0x0000ffff) << 16))
78 #define	__word_swap_int(x) (__builtin_constant_p(x) ? \
79 	__word_swap_int_const(x) : __word_swap_int_var(x))
80 
81 #else	/* __OPTIMIZE__ */
82 
83 #define	__word_swap_int(x) __word_swap_int_var(x)
84 
85 #endif	/* __OPTIMIZE__ */
86 
87 #define __byte_swap_int_var(x) \
88 __extension__ ({ register __uint32_t __X = (x); \
89    __asm ("bswap %0" : "+r" (__X)); \
90    __X; })
91 
92 #ifdef __OPTIMIZE__
93 
94 #define	__byte_swap_int_const(x) \
95 	((((x) & 0xff000000) >> 24) | \
96 	 (((x) & 0x00ff0000) >>  8) | \
97 	 (((x) & 0x0000ff00) <<  8) | \
98 	 (((x) & 0x000000ff) << 24))
99 #define	__byte_swap_int(x) (__builtin_constant_p(x) ? \
100 	__byte_swap_int_const(x) : __byte_swap_int_var(x))
101 
102 #else	/* __OPTIMIZE__ */
103 
104 #define	__byte_swap_int(x) __byte_swap_int_var(x)
105 
106 #endif	/* __OPTIMIZE__ */
107 
108 #define __byte_swap_long_var(x) \
109 __extension__ ({ register __uint64_t __X = (x); \
110    __asm ("bswap %0" : "+r" (__X)); \
111    __X; })
112 
113 #ifdef __OPTIMIZE__
114 
115 #define	__byte_swap_long_const(x) \
116 	(((x >> 56) | \
117 	 ((x >> 40) & 0xff00) | \
118 	 ((x >> 24) & 0xff0000) | \
119 	 ((x >> 8) & 0xff000000) | \
120 	 ((x << 8) & (0xfful << 32)) | \
121 	 ((x << 24) & (0xfful << 40)) | \
122 	 ((x << 40) & (0xfful << 48)) | \
123 	 ((x << 56))))
124 
125 #define	__byte_swap_long(x) (__builtin_constant_p(x) ? \
126 	__byte_swap_long_const(x) : __byte_swap_long_var(x))
127 
128 #else	/* __OPTIMIZE__ */
129 
130 #define	__byte_swap_long(x) __byte_swap_long_var(x)
131 
132 #endif	/* __OPTIMIZE__ */
133 
134 #define __byte_swap_word_var(x) \
135 __extension__ ({ register __uint16_t __X = (x); \
136    __asm ("xchgb %h0, %b0" : "+Q" (__X)); \
137    __X; })
138 
139 #ifdef __OPTIMIZE__
140 
141 #define	__byte_swap_word_const(x) \
142 	((((x) & 0xff00) >> 8) | \
143 	 (((x) & 0x00ff) << 8))
144 
145 #define	__byte_swap_word(x) (__builtin_constant_p(x) ? \
146 	__byte_swap_word_const(x) : __byte_swap_word_var(x))
147 
148 #else	/* __OPTIMIZE__ */
149 
150 #define	__byte_swap_word(x) __byte_swap_word_var(x)
151 
152 #endif	/* __OPTIMIZE__ */
153 
154 static __inline __uint64_t
155 __bswap64(__uint64_t _x)
156 {
157 
158 	return (__byte_swap_long(_x));
159 }
160 
161 static __inline __uint32_t
162 __bswap32(__uint32_t _x)
163 {
164 
165 	return (__byte_swap_int(_x));
166 }
167 
168 static __inline __uint16_t
169 __bswap16(__uint16_t _x)
170 {
171 
172 	return (__byte_swap_word(_x));
173 }
174 
175 #define	__htonl(x)	__bswap32(x)
176 #define	__htons(x)	__bswap16(x)
177 #define	__ntohl(x)	__bswap32(x)
178 #define	__ntohs(x)	__bswap16(x)
179 
180 #else /* !__GNUC__ */
181 
182 /*
183  * No optimizations are available for this compiler.  Fall back to
184  * non-optimized functions by defining the constant usually used to prevent
185  * redefinition.
186  */
187 #define	_BYTEORDER_FUNC_DEFINED
188 
189 #endif /* __GNUC__ */
190 
191 #endif /* !_MACHINE_ENDIAN_H_ */
192