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1 /*	$NetBSD: byte_swap.h,v 1.10 2006/01/30 22:46:36 dsl Exp $	*/
2 
3 /*-
4  * Copyright (c) 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Charles M. Hannum.
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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #ifndef _I386_BYTE_SWAP_H_
40 #define	_I386_BYTE_SWAP_H_
41 
42 #include <sys/types.h>
43 
44 #if defined(_KERNEL_OPT)
45 #include "opt_cputype.h"
46 #endif
47 
48 #ifdef  __GNUC__
49 #include <sys/types.h>
50 __BEGIN_DECLS
51 
52 #define	__BYTE_SWAP_U32_VARIABLE __byte_swap_u32_variable
53 static __inline uint32_t __byte_swap_u32_variable(uint32_t);
54 static __inline uint32_t
__byte_swap_u32_variable(uint32_t x)55 __byte_swap_u32_variable(uint32_t x)
56 {
57 	__asm volatile (
58 #if defined(_KERNEL) && !defined(_LKM) && !defined(I386_CPU)
59 	    "bswap %1"
60 #else
61 	    "rorw $8, %w1\n\trorl $16, %1\n\trorw $8, %w1"
62 #endif
63 	    : "=r" (x) : "0" (x));
64 	return (x);
65 }
66 
67 #define	__BYTE_SWAP_U16_VARIABLE __byte_swap_u16_variable
68 static __inline uint16_t __byte_swap_u16_variable(uint16_t);
69 static __inline uint16_t
__byte_swap_u16_variable(uint16_t x)70 __byte_swap_u16_variable(uint16_t x)
71 {
72 	__asm volatile ("rorw $8, %w1" : "=r" (x) : "0" (x));
73 	return (x);
74 }
75 
76 __END_DECLS
77 #endif
78 
79 #endif /* !_I386_BYTE_SWAP_H_ */
80