1/* $NetBSD: byte_swap.h,v 1.4 2017/01/17 11:09:36 rin Exp $ */
  2
  3/*-
  4 * Copyright (c) 2014 The NetBSD Foundation, Inc.
  5 * All rights reserved.
  6 *
  7 * This code is derived from software contributed to The NetBSD Foundation
  8 * by Matt Thomas of 3am Software Foundry.
  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 _ARM_BYTE_SWAP_H_
 33#define	_ARM_BYTE_SWAP_H_
 34
 35#ifdef __aarch64__
 36
 37#ifdef _LOCORE
 38
 39#define	BSWAP16(_src, _dst)		\
 40	rev16	_dst, _src
 41#define	BSWAP32(_src, _dst)		\
 42	rev	_dst, _src
 43#define	BSWAP64(_src, _dst)		\
 44	rev	_dst, _src
 45
 46#else
 47
 48#ifdef __GNUC__
 49#include <sys/types.h>
 50__BEGIN_DECLS
 51
 52#define	__BYTE_SWAP_U64_VARIABLE __byte_swap_u64_variable
 53static __inline uint64_t
 54__byte_swap_u64_variable(uint64_t v)
 55{
 56	if (!__builtin_constant_p(v)) {
 57		__asm("rev\t%x0, %x1" : "=r" (v) : "0" (v));
 58		return v;
 59	}
 60
 61	v =   ((v & 0x000000ff) << (56 -  0)) | ((v >> (56 -  0)) & 0x000000ff)
 62	    | ((v & 0x0000ff00) << (48 -  8)) | ((v >> (48 -  8)) & 0x0000ff00) 
 63	    | ((v & 0x00ff0000) << (40 - 16)) | ((v >> (40 - 16)) & 0x00ff0000)
 64	    | ((v & 0xff000000) << (32 - 24)) | ((v >> (32 - 24)) & 0xff000000);
 65
 66	return v;
 67}
 68
 69#define	__BYTE_SWAP_U32_VARIABLE __byte_swap_u32_variable
 70static __inline uint32_t
 71__byte_swap_u32_variable(uint32_t v)
 72{
 73	if (!__builtin_constant_p(v)) {
 74		__asm("rev\t%w0, %w1" : "=r" (v) : "0" (v));
 75		return v;
 76	}
 77
 78	v =   ((v & 0x00ff) << (24 - 0)) | ((v >> (24 - 0)) & 0x00ff)
 79	    | ((v & 0xff00) << (16 - 8)) | ((v >> (16 - 8)) & 0xff00);
 80
 81	return v;
 82}
 83
 84#define	__BYTE_SWAP_U16_VARIABLE __byte_swap_u16_variable
 85static __inline uint16_t
 86__byte_swap_u16_variable(uint16_t v)
 87{
 88
 89	if (!__builtin_constant_p(v)) {
 90		uint32_t v32 = v;
 91		__asm("rev16\t%w0, %w1" : "=r" (v32) : "0" (v32));
 92		return (uint16_t)v32;
 93	}
 94
 95	v &= 0xffff;
 96	v = (uint16_t)((v >> 8) | (v << 8));
 97
 98	return v;
 99}
100
101__END_DECLS
102#endif
103
104#endif	/* _LOCORE */
105
106#elif defined(__arm__)
107
108#include <arm/asm.h>
109
110#endif
111
112#endif /* _ARM_BYTE_SWAP_H_ */