1 /*
2 * Copyright (c) 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__OSBYTEORDERARM_H
30 #define _OS__OSBYTEORDERARM_H
31
32 #if defined (__arm__) || defined(__arm64__)
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 /* Reduces to 'rev16' with clang */
55 return (__uint16_t)(_data << 8 | _data >> 8);
56 }
57
58 __DARWIN_OS_INLINE
59 __uint32_t
_OSSwapInt32(__uint32_t _data)60 _OSSwapInt32(
61 __uint32_t _data
62 )
63 {
64 #if defined(__llvm__)
65 _data = __builtin_bswap32(_data);
66 #else
67 /* This actually generates the best code */
68 _data = (((_data ^ (_data >> 16 | (_data << 16))) & 0xFF00FFFF) >> 8) ^ (_data >> 8 | _data << 24);
69 #endif
70
71 return _data;
72 }
73
74 __DARWIN_OS_INLINE
75 __uint64_t
_OSSwapInt64(__uint64_t _data)76 _OSSwapInt64(
77 __uint64_t _data
78 )
79 {
80 #if defined(__llvm__)
81 return __builtin_bswap64(_data);
82 #else
83 union {
84 __uint64_t _ull;
85 __uint32_t _ul[2];
86 } _u;
87
88 /* This actually generates the best code */
89 _u._ul[0] = (__uint32_t)(_data >> 32);
90 _u._ul[1] = (__uint32_t)(_data & 0xffffffff);
91 _u._ul[0] = _OSSwapInt32(_u._ul[0]);
92 _u._ul[1] = _OSSwapInt32(_u._ul[1]);
93 return _u._ull;
94 #endif
95 }
96
97 #endif /* defined (__arm__) || defined(__arm64__) */
98
99 #endif /* ! _OS__OSBYTEORDERARM_H */
100