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byte_swap.h revision 1.2.6.2
      1  1.2.6.2  jdolecek /*	$NetBSD: byte_swap.h,v 1.2.6.2 2002/09/06 08:32:35 jdolecek Exp $	*/
      2  1.2.6.2  jdolecek 
      3  1.2.6.2  jdolecek /*-
      4  1.2.6.2  jdolecek  * Copyright (c) 1997, 1999, 2002 The NetBSD Foundation, Inc.
      5  1.2.6.2  jdolecek  * All rights reserved.
      6  1.2.6.2  jdolecek  *
      7  1.2.6.2  jdolecek  * This code is derived from software contributed to The NetBSD Foundation
      8  1.2.6.2  jdolecek  * by Charles M. Hannum, Neil A. Carson, and Jason R. Thorpe.
      9  1.2.6.2  jdolecek  *
     10  1.2.6.2  jdolecek  * Redistribution and use in source and binary forms, with or without
     11  1.2.6.2  jdolecek  * modification, are permitted provided that the following conditions
     12  1.2.6.2  jdolecek  * are met:
     13  1.2.6.2  jdolecek  * 1. Redistributions of source code must retain the above copyright
     14  1.2.6.2  jdolecek  *    notice, this list of conditions and the following disclaimer.
     15  1.2.6.2  jdolecek  * 2. Redistributions in binary form must reproduce the above copyright
     16  1.2.6.2  jdolecek  *    notice, this list of conditions and the following disclaimer in the
     17  1.2.6.2  jdolecek  *    documentation and/or other materials provided with the distribution.
     18  1.2.6.2  jdolecek  * 3. All advertising materials mentioning features or use of this software
     19  1.2.6.2  jdolecek  *    must display the following acknowledgement:
     20  1.2.6.2  jdolecek  *	This product includes software developed by the NetBSD
     21  1.2.6.2  jdolecek  *	Foundation, Inc. and its contributors.
     22  1.2.6.2  jdolecek  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  1.2.6.2  jdolecek  *    contributors may be used to endorse or promote products derived
     24  1.2.6.2  jdolecek  *    from this software without specific prior written permission.
     25  1.2.6.2  jdolecek  *
     26  1.2.6.2  jdolecek  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  1.2.6.2  jdolecek  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  1.2.6.2  jdolecek  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  1.2.6.2  jdolecek  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  1.2.6.2  jdolecek  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  1.2.6.2  jdolecek  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  1.2.6.2  jdolecek  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  1.2.6.2  jdolecek  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  1.2.6.2  jdolecek  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  1.2.6.2  jdolecek  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  1.2.6.2  jdolecek  * POSSIBILITY OF SUCH DAMAGE.
     37  1.2.6.2  jdolecek  */
     38  1.2.6.2  jdolecek 
     39  1.2.6.2  jdolecek #ifndef _ARM_BYTE_SWAP_H_
     40  1.2.6.2  jdolecek #define	_ARM_BYTE_SWAP_H_
     41  1.2.6.2  jdolecek 
     42  1.2.6.2  jdolecek #include <sys/types.h>
     43  1.2.6.2  jdolecek 
     44  1.2.6.2  jdolecek static __inline u_int32_t
     45  1.2.6.2  jdolecek __byte_swap_32_variable(u_int32_t v)
     46  1.2.6.2  jdolecek {
     47  1.2.6.2  jdolecek 	u_int32_t t1;
     48  1.2.6.2  jdolecek 
     49  1.2.6.2  jdolecek 	t1 = v ^ ((v << 16) | (v >> 16));
     50  1.2.6.2  jdolecek 	t1 &= 0xff00ffff;
     51  1.2.6.2  jdolecek 	v = (v >> 8) | (v << 24);
     52  1.2.6.2  jdolecek 	v ^= (t1 >> 8);
     53  1.2.6.2  jdolecek 
     54  1.2.6.2  jdolecek 	return (v);
     55  1.2.6.2  jdolecek }
     56  1.2.6.2  jdolecek 
     57  1.2.6.2  jdolecek static __inline u_int16_t
     58  1.2.6.2  jdolecek __byte_swap_16_variable(u_int16_t v)
     59  1.2.6.2  jdolecek {
     60  1.2.6.2  jdolecek 
     61  1.2.6.2  jdolecek 	__asm __volatile(
     62  1.2.6.2  jdolecek 		"mov	%0, %1, ror #8\n"
     63  1.2.6.2  jdolecek 		"orr	%0, %0, %0, lsr #16\n"
     64  1.2.6.2  jdolecek 		"bic	%0, %0, %0, lsl #16"
     65  1.2.6.2  jdolecek 	: "=r" (v)
     66  1.2.6.2  jdolecek 	: "0" (v));
     67  1.2.6.2  jdolecek 
     68  1.2.6.2  jdolecek 	return (v);
     69  1.2.6.2  jdolecek }
     70  1.2.6.2  jdolecek 
     71  1.2.6.2  jdolecek #ifdef __OPTIMIZE__
     72  1.2.6.2  jdolecek 
     73  1.2.6.2  jdolecek #define __byte_swap_32_constant(x)	\
     74  1.2.6.2  jdolecek 	((((x) & 0xff000000) >> 24) |	\
     75  1.2.6.2  jdolecek 	 (((x) & 0x00ff0000) >>  8) |	\
     76  1.2.6.2  jdolecek 	 (((x) & 0x0000ff00) <<  8) |	\
     77  1.2.6.2  jdolecek 	 (((x) & 0x000000ff) << 24))
     78  1.2.6.2  jdolecek 
     79  1.2.6.2  jdolecek #define	__byte_swap_16_constant(x)	\
     80  1.2.6.2  jdolecek 	((((x) & 0xff00) >> 8) |	\
     81  1.2.6.2  jdolecek 	 (((x) & 0x00ff) << 8))
     82  1.2.6.2  jdolecek 
     83  1.2.6.2  jdolecek #define	__byte_swap_32(x)		\
     84  1.2.6.2  jdolecek 	(__builtin_constant_p((x)) ?	\
     85  1.2.6.2  jdolecek 	 __byte_swap_32_constant(x) :	__byte_swap_32_variable(x))
     86  1.2.6.2  jdolecek 
     87  1.2.6.2  jdolecek #define	__byte_swap_16(x)		\
     88  1.2.6.2  jdolecek 	(__builtin_constant_p((x)) ?	\
     89  1.2.6.2  jdolecek 	 __byte_swap_16_constant(x) : __byte_swap_16_variable(x))
     90  1.2.6.2  jdolecek 
     91  1.2.6.2  jdolecek #else
     92  1.2.6.2  jdolecek 
     93  1.2.6.2  jdolecek #define	__byte_swap_32(x)	__byte_swap_32_variable(x)
     94  1.2.6.2  jdolecek #define	__byte_swap_16(x)	__byte_swap_16_variable(x)
     95  1.2.6.2  jdolecek 
     96  1.2.6.2  jdolecek #endif /* __OPTIMIZE__ */
     97  1.2.6.2  jdolecek 
     98  1.2.6.2  jdolecek #endif /* _ARM_BYTE_SWAP_H_ */
     99