NetBSD/sys/arch/arm/include/byte_swap.h

99 lines
3.1 KiB
C

/* $NetBSD: byte_swap.h,v 1.3 2002/11/08 01:31:23 thorpej Exp $ */
/*-
* Copyright (c) 1997, 1999, 2002 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Charles M. Hannum, Neil A. Carson, and Jason R. Thorpe.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _ARM_BYTE_SWAP_H_
#define _ARM_BYTE_SWAP_H_
#include <sys/types.h>
static __inline u_int32_t
__byte_swap_32_variable(u_int32_t v)
{
u_int32_t t1;
t1 = v ^ ((v << 16) | (v >> 16));
t1 &= 0xff00ffffU;
v = (v >> 8) | (v << 24);
v ^= (t1 >> 8);
return (v);
}
static __inline u_int16_t
__byte_swap_16_variable(u_int16_t v)
{
__asm __volatile(
"mov %0, %1, ror #8\n"
"orr %0, %0, %0, lsr #16\n"
"bic %0, %0, %0, lsl #16"
: "=r" (v)
: "0" (v));
return (v);
}
#ifdef __OPTIMIZE__
#define __byte_swap_32_constant(x) \
((((x) & 0xff000000U) >> 24) | \
(((x) & 0x00ff0000U) >> 8) | \
(((x) & 0x0000ff00U) << 8) | \
(((x) & 0x000000ffU) << 24))
#define __byte_swap_16_constant(x) \
((((x) & 0xff00) >> 8) | \
(((x) & 0x00ff) << 8))
#define __byte_swap_32(x) \
(__builtin_constant_p((x)) ? \
__byte_swap_32_constant(x) : __byte_swap_32_variable(x))
#define __byte_swap_16(x) \
(__builtin_constant_p((x)) ? \
__byte_swap_16_constant(x) : __byte_swap_16_variable(x))
#else
#define __byte_swap_32(x) __byte_swap_32_variable(x)
#define __byte_swap_16(x) __byte_swap_16_variable(x)
#endif /* __OPTIMIZE__ */
#endif /* _ARM_BYTE_SWAP_H_ */