1/* $NetBSD: byte_swap.h,v 1.4.52.1 2025/12/18 19:57:53 martin Exp $ */
2
3/*-
4 * Copyright (c) 2014 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Matt Thomas of 3am Software Foundry.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#ifndef _ARM_BYTE_SWAP_H_
33#define _ARM_BYTE_SWAP_H_
34
35#ifdef __aarch64__
36
37#ifdef _LOCORE
38
39#define BSWAP16(_src, _dst) \
40 rev16 _dst, _src
41#define BSWAP32(_src, _dst) \
42 rev _dst, _src
43#define BSWAP64(_src, _dst) \
44 rev _dst, _src
45
46#else
47
48#ifdef __GNUC__
49#include <sys/stdint.h>
50
51__BEGIN_DECLS
52
53#define __BYTE_SWAP_U64_VARIABLE __byte_swap_u64_variable
54static __inline uint64_t
55__byte_swap_u64_variable(uint64_t v)
56{
57 if (!__builtin_constant_p(v)) {
58 __asm("rev\t%x0, %x1" : "=r" (v) : "0" (v));
59 return v;
60 }
61
62 v = ((v & 0x000000ff) << (56 - 0)) | ((v >> (56 - 0)) & 0x000000ff)
63 | ((v & 0x0000ff00) << (48 - 8)) | ((v >> (48 - 8)) & 0x0000ff00)
64 | ((v & 0x00ff0000) << (40 - 16)) | ((v >> (40 - 16)) & 0x00ff0000)
65 | ((v & 0xff000000) << (32 - 24)) | ((v >> (32 - 24)) & 0xff000000);
66
67 return v;
68}
69
70#define __BYTE_SWAP_U32_VARIABLE __byte_swap_u32_variable
71static __inline uint32_t
72__byte_swap_u32_variable(uint32_t v)
73{
74 if (!__builtin_constant_p(v)) {
75 __asm("rev\t%w0, %w1" : "=r" (v) : "0" (v));
76 return v;
77 }
78
79 v = ((v & 0x00ff) << (24 - 0)) | ((v >> (24 - 0)) & 0x00ff)
80 | ((v & 0xff00) << (16 - 8)) | ((v >> (16 - 8)) & 0xff00);
81
82 return v;
83}
84
85#define __BYTE_SWAP_U16_VARIABLE __byte_swap_u16_variable
86static __inline uint16_t
87__byte_swap_u16_variable(uint16_t v)
88{
89
90 if (!__builtin_constant_p(v)) {
91 uint32_t v32 = v;
92 __asm("rev16\t%w0, %w1" : "=r" (v32) : "0" (v32));
93 return (uint16_t)v32;
94 }
95
96 v &= 0xffff;
97 v = (uint16_t)((v >> 8) | (v << 8));
98
99 return v;
100}
101
102__END_DECLS
103#endif
104
105#endif /* _LOCORE */
106
107#elif defined(__arm__)
108
109#include <arm/asm.h>
110
111#endif
112
113#endif /* _ARM_BYTE_SWAP_H_ */