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
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
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
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 */