xref: /xnu-11215.61.5/libkern/libkern/i386/_OSByteOrder.h (revision 4f1223e81cd707a65cc109d0b8ad6653699da3c4)
1 /*
2  * Copyright (c) 2006-2023 Apple 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__OSBYTEORDERI386_H
30 #define _OS__OSBYTEORDERI386_H
31 
32 #if defined(__i386__) || defined(__x86_64__)
33 
34 #include <sys/_types.h>
35 
36 #if !defined(__DARWIN_OS_INLINE)
37 # if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
38 #        define __DARWIN_OS_INLINE static inline
39 # elif defined(__MWERKS__) || defined(__cplusplus)
40 #        define __DARWIN_OS_INLINE static inline
41 # else
42 #        define __DARWIN_OS_INLINE static __inline__
43 # endif
44 #endif
45 
46 /* Generic byte swapping functions. */
47 
48 __DARWIN_OS_INLINE
49 __uint16_t
_OSSwapInt16(__uint16_t _data)50 _OSSwapInt16(
51 	__uint16_t        _data
52 	)
53 {
54 	return (__uint16_t)((_data << 8) | (_data >> 8));
55 }
56 
57 __DARWIN_OS_INLINE
58 __uint32_t
_OSSwapInt32(__uint32_t _data)59 _OSSwapInt32(
60 	__uint32_t        _data
61 	)
62 {
63 #if defined(__llvm__)
64 	return __builtin_bswap32(_data);
65 #else
66 	__asm__ ("bswap   %0" : "+r" (_data));
67 	return _data;
68 #endif
69 }
70 
71 #if defined(__llvm__)
72 __DARWIN_OS_INLINE
73 __uint64_t
_OSSwapInt64(__uint64_t _data)74 _OSSwapInt64(
75 	__uint64_t        _data
76 	)
77 {
78 	return __builtin_bswap64(_data);
79 }
80 
81 #elif defined(__i386__)
82 __DARWIN_OS_INLINE
83 __uint64_t
_OSSwapInt64(__uint64_t _data)84 _OSSwapInt64(
85 	__uint64_t        _data
86 	)
87 {
88 	__asm__ ("bswap   %%eax\n\t"
89                  "bswap   %%edx\n\t"
90                  "xchgl   %%eax, %%edx"
91                  : "+A" (_data));
92 	return _data;
93 }
94 #elif defined(__x86_64__)
95 __DARWIN_OS_INLINE
96 __uint64_t
_OSSwapInt64(__uint64_t _data)97 _OSSwapInt64(
98 	__uint64_t        _data
99 	)
100 {
101 	__asm__ ("bswap   %0" : "+r" (_data));
102 	return _data;
103 }
104 #else
105 #error Unknown architecture
106 #endif
107 
108 #endif /* defined(__i386__) || defined(__x86_64__) */
109 
110 #endif /* ! _OS__OSBYTEORDERI386_H */
111