xref: /xnu-8020.121.3/libkern/libkern/_OSByteOrder.h (revision fdd8201d7b966f0c3ea610489d29bd841d358941)
1 /*
2  * Copyright (c) 2006 Apple Computer, Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 
29 #ifndef _OS__OSBYTEORDER_H
30 #define _OS__OSBYTEORDER_H
31 
32 /*
33  * This header is normally included from <libkern/OSByteOrder.h>.  However,
34  * <sys/_endian.h> also includes this in the case of little-endian
35  * architectures, so that we can map OSByteOrder routines to the hton* and ntoh*
36  * macros.  This results in the asymmetry below; we only include
37  * <libkern/arch/_OSByteOrder.h> for little-endian architectures.
38  */
39 
40 #include <sys/_types.h>
41 
42 /* Macros for swapping constant values in the preprocessing stage. */
43 #define __DARWIN_OSSwapConstInt16(x) \
44     ((__uint16_t)((((__uint16_t)(x) & 0xff00U) >> 8) | \
45 	        (((__uint16_t)(x) & 0x00ffU) << 8)))
46 
47 #define __DARWIN_OSSwapConstInt32(x) \
48     ((__uint32_t)((((__uint32_t)(x) & 0xff000000U) >> 24) | \
49 	        (((__uint32_t)(x) & 0x00ff0000U) >>  8) | \
50 	        (((__uint32_t)(x) & 0x0000ff00U) <<  8) | \
51 	        (((__uint32_t)(x) & 0x000000ffU) << 24)))
52 
53 #define __DARWIN_OSSwapConstInt64(x) \
54     ((__uint64_t)((((__uint64_t)(x) & 0xff00000000000000ULL) >> 56) | \
55 	        (((__uint64_t)(x) & 0x00ff000000000000ULL) >> 40) | \
56 	        (((__uint64_t)(x) & 0x0000ff0000000000ULL) >> 24) | \
57 	        (((__uint64_t)(x) & 0x000000ff00000000ULL) >>  8) | \
58 	        (((__uint64_t)(x) & 0x00000000ff000000ULL) <<  8) | \
59 	        (((__uint64_t)(x) & 0x0000000000ff0000ULL) << 24) | \
60 	        (((__uint64_t)(x) & 0x000000000000ff00ULL) << 40) | \
61 	        (((__uint64_t)(x) & 0x00000000000000ffULL) << 56)))
62 
63 #if defined(__GNUC__)
64 
65 #if !defined(__DARWIN_OS_INLINE)
66 # if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
67 #        define __DARWIN_OS_INLINE static inline
68 # elif defined(__MWERKS__) || defined(__cplusplus)
69 #        define __DARWIN_OS_INLINE static inline
70 # else
71 #        define __DARWIN_OS_INLINE static __inline__
72 # endif
73 #endif
74 
75 #if defined(__i386__) || defined(__x86_64__)
76 #include <libkern/i386/_OSByteOrder.h>
77 #endif
78 
79 #if defined (__arm__) || defined(__arm64__)
80 #include <libkern/arm/OSByteOrder.h>
81 #endif
82 
83 
84 #define __DARWIN_OSSwapInt16(x) \
85     ((__uint16_t)(__builtin_constant_p(x) ? __DARWIN_OSSwapConstInt16(x) : _OSSwapInt16(x)))
86 
87 #define __DARWIN_OSSwapInt32(x) \
88     (__builtin_constant_p(x) ? __DARWIN_OSSwapConstInt32(x) : _OSSwapInt32(x))
89 
90 #define __DARWIN_OSSwapInt64(x) \
91     (__builtin_constant_p(x) ? __DARWIN_OSSwapConstInt64(x) : _OSSwapInt64(x))
92 
93 #else /* ! __GNUC__ */
94 
95 #if defined(__i386__) || defined(__x86_64__)
96 
97 __DARWIN_OS_INLINE
98 uint16_t
_OSSwapInt16(uint16_t data)99 _OSSwapInt16(
100 	uint16_t                    data
101 	)
102 {
103 	return __DARWIN_OSSwapConstInt16(data);
104 }
105 
106 __DARWIN_OS_INLINE
107 uint32_t
_OSSwapInt32(uint32_t data)108 _OSSwapInt32(
109 	uint32_t                    data
110 	)
111 {
112 	return __DARWIN_OSSwapConstInt32(data);
113 }
114 
115 __DARWIN_OS_INLINE
116 uint64_t
_OSSwapInt64(uint64_t data)117 _OSSwapInt64(
118 	uint64_t                    data
119 	)
120 {
121 	return __DARWIN_OSSwapConstInt64(data);
122 }
123 #endif
124 
125 #define __DARWIN_OSSwapInt16(x) _OSSwapInt16(x)
126 
127 #define __DARWIN_OSSwapInt32(x) _OSSwapInt32(x)
128 
129 #define __DARWIN_OSSwapInt64(x) _OSSwapInt64(x)
130 
131 #endif /* __GNUC__ */
132 
133 #endif /* ! _OS__OSBYTEORDER_H */
134