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byte_swap.h revision 1.12 
      1 /*	$NetBSD: byte_swap.h,v 1.12 2007/09/26 19:48:41 ad 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 __BEGIN_DECLS
     50 
     51 #define	__BYTE_SWAP_U32_VARIABLE __byte_swap_u32_variable
     52 static __inline uint32_t __byte_swap_u32_variable(uint32_t);
     53 static __inline uint32_t
     54 __byte_swap_u32_variable(uint32_t x)
     55 {
     56 	__asm volatile (
     57 	    "bswap %1"
     58 	    : "=r" (x) : "0" (x));
     59 	return (x);
     60 }
     61 
     62 #define	__BYTE_SWAP_U16_VARIABLE __byte_swap_u16_variable
     63 static __inline uint16_t __byte_swap_u16_variable(uint16_t);
     64 static __inline uint16_t
     65 __byte_swap_u16_variable(uint16_t x)
     66 {
     67 	__asm volatile ("rorw $8, %w1" : "=r" (x) : "0" (x));
     68 	return (x);
     69 }
     70 
     71 __END_DECLS
     72 #elif defined(_KERNEL) || defined(_LKM)
     73 #define	__BYTE_SWAP_U32_VARIABLE __byte_swap_u32_variable
     74 #define	__BYTE_SWAP_U16_VARIABLE __byte_swap_u16_variable
     75 uint32_t	__byte_swap_u32_variable(uint32_t);
     76 uint16_t	__byte_swap_u16_variable(uint16_t);
     77 #endif
     78 
     79 #endif /* !_I386_BYTE_SWAP_H_ */
     80