byte_swap.h revision 1.5 
1/* $NetBSD: byte_swap.h,v 1.5 2020/04/04 21:13:20 christos 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 _RISCV_BYTE_SWAP_H_
33#define	_RISCV_BYTE_SWAP_H_
34
35#ifdef _LOCORE
36
37#define	BSWAP16(_src, _dst, _tmp)	\
38	andi	_dst, _src, 0xff	;\
39	slli	_dst, _dst, 8		;\
40	srli	_tmp, _src, 8		;\
41	and	_tmp, _tmp, 0xff	;\
42	ori	_dst, _dst, _tmp
43
44#define BSWAP32(_src, _dst, _tmp)	\
45	li	v1, 0xff00		;\
46	slli	_dst, _src, 24		;\
47	srli	_tmp, _src, 24		;\
48	ori	_dst, _dst, _tmp	;\
49	and	_tmp, _src, v1		;\
50	slli	_tmp, _src, 8		;\
51	ori	_dst, _dst, _tmp	;\
52	srli	_tmp, _src, 8		;\
53	and	_tmp, _tmp, v1		;\
54	ori	_dst, _dst, _tmp
55
56#else
57
58#include <sys/types.h>
59__BEGIN_DECLS
60
61#define	__BYTE_SWAP_U64_VARIABLE __byte_swap_u64_variable
62static __inline uint64_t
63__byte_swap_u64_variable(uint64_t v)
64{
65	const uint64_t m1 = 0x0000ffff0000ffffull;
66	const uint64_t m0 = 0x00ff00ff00ff00ffull;
67
68	v = (v >> 32) | (v << 32);
69	v = ((v >> 16) & m1) | ((v & m1) << 16);
70	v = ((v >> 8) & m0) | ((v & m0) << 8);
71
72	return v;
73}
74
75#define	__BYTE_SWAP_U32_VARIABLE __byte_swap_u32_variable
76static __inline uint32_t
77__byte_swap_u32_variable(uint32_t v)
78{
79	const uint32_t m = 0xff00ff;
80
81	v = (v >> 16) | (v << 16);
82	v = ((v >> 8) & m) | ((v & m) << 8);
83
84	return v;
85}
86
87#define	__BYTE_SWAP_U16_VARIABLE __byte_swap_u16_variable
88static __inline uint16_t
89__byte_swap_u16_variable(uint16_t v)
90{
91	/*LINTED*/
92	return (uint16_t)((v >> 8) | (v << 8));
93}
94
95__END_DECLS
96
97#endif	/* _LOCORE */
98
99#endif /* _RISCV_BYTE_SWAP_H_ */
100