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      1 /*	$NetBSD: byte_swap.h,v 1.17 2020/08/10 10:59:33 rin 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  *
     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 _I386_BYTE_SWAP_H_
     33 #define	_I386_BYTE_SWAP_H_
     34 
     35 #include <sys/types.h>
     36 
     37 #ifdef  __GNUC__
     38 __BEGIN_DECLS
     39 
     40 #define	__BYTE_SWAP_U32_VARIABLE __byte_swap_u32_variable
     41 static __inline uint32_t __byte_swap_u32_variable(uint32_t);
     42 static __inline uint32_t
     43 __byte_swap_u32_variable(uint32_t x)
     44 {
     45 	__asm volatile (
     46 	    "bswap %1"
     47 	    : "=r" (x) : "0" (x));
     48 	return (x);
     49 }
     50 
     51 #define	__BYTE_SWAP_U16_VARIABLE __byte_swap_u16_variable
     52 static __inline uint16_t __byte_swap_u16_variable(uint16_t);
     53 static __inline uint16_t
     54 __byte_swap_u16_variable(uint16_t x)
     55 {
     56 	__asm volatile ("rorw $8, %w1" : "=r" (x) : "0" (x));
     57 	return (x);
     58 }
     59 
     60 __END_DECLS
     61 #elif defined(_KERNEL)
     62 #define	__BYTE_SWAP_U32_VARIABLE __byte_swap_u32_variable
     63 #define	__BYTE_SWAP_U16_VARIABLE __byte_swap_u16_variable
     64 uint32_t	__byte_swap_u32_variable(uint32_t);
     65 uint16_t	__byte_swap_u16_variable(uint16_t);
     66 #endif
     67 
     68 #endif /* !_I386_BYTE_SWAP_H_ */
     69