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      1 /* $NetBSD: byte_swap.h,v 1.5 2020/04/04 21:13:20 christos 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 _RISCV_BYTE_SWAP_H_
     33 #define	_RISCV_BYTE_SWAP_H_
     34 
     35 #ifdef _LOCORE
     36 
     37 #define	BSWAP16(_src, _dst, _tmp)	\
     38 	andi	_dst, _src, 0xff	;\
     39 	slli	_dst, _dst, 8		;\
     40 	srli	_tmp, _src, 8		;\
     41 	and	_tmp, _tmp, 0xff	;\
     42 	ori	_dst, _dst, _tmp
     43 
     44 #define BSWAP32(_src, _dst, _tmp)	\
     45 	li	v1, 0xff00		;\
     46 	slli	_dst, _src, 24		;\
     47 	srli	_tmp, _src, 24		;\
     48 	ori	_dst, _dst, _tmp	;\
     49 	and	_tmp, _src, v1		;\
     50 	slli	_tmp, _src, 8		;\
     51 	ori	_dst, _dst, _tmp	;\
     52 	srli	_tmp, _src, 8		;\
     53 	and	_tmp, _tmp, v1		;\
     54 	ori	_dst, _dst, _tmp
     55 
     56 #else
     57 
     58 #include <sys/types.h>
     59 __BEGIN_DECLS
     60 
     61 #define	__BYTE_SWAP_U64_VARIABLE __byte_swap_u64_variable
     62 static __inline uint64_t
     63 __byte_swap_u64_variable(uint64_t v)
     64 {
     65 	const uint64_t m1 = 0x0000ffff0000ffffull;
     66 	const uint64_t m0 = 0x00ff00ff00ff00ffull;
     67 
     68 	v = (v >> 32) | (v << 32);
     69 	v = ((v >> 16) & m1) | ((v & m1) << 16);
     70 	v = ((v >> 8) & m0) | ((v & m0) << 8);
     71 
     72 	return v;
     73 }
     74 
     75 #define	__BYTE_SWAP_U32_VARIABLE __byte_swap_u32_variable
     76 static __inline uint32_t
     77 __byte_swap_u32_variable(uint32_t v)
     78 {
     79 	const uint32_t m = 0xff00ff;
     80 
     81 	v = (v >> 16) | (v << 16);
     82 	v = ((v >> 8) & m) | ((v & m) << 8);
     83 
     84 	return v;
     85 }
     86 
     87 #define	__BYTE_SWAP_U16_VARIABLE __byte_swap_u16_variable
     88 static __inline uint16_t
     89 __byte_swap_u16_variable(uint16_t v)
     90 {
     91 	/*LINTED*/
     92 	return (uint16_t)((v >> 8) | (v << 8));
     93 }
     94 
     95 __END_DECLS
     96 
     97 #endif	/* _LOCORE */
     98 
     99 #endif /* _RISCV_BYTE_SWAP_H_ */
    100