1 /* $NetBSD: byte_swap.h,v 1.8 2008/04/28 20:23:14 martin Exp $ */ 2 3 /*- 4 * Copyright (c) 1997, 1999, 2002 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, Neil A. Carson, and Jason R. Thorpe. 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 __GNUC__ 36 #include <sys/types.h> 37 __BEGIN_DECLS 38 39 #define __BYTE_SWAP_U32_VARIABLE __byte_swap_u32_variable 40 static __inline uint32_t 41 __byte_swap_u32_variable(uint32_t v) 42 { 43 #ifdef _ARM_ARCH_6 44 __asm("rev\t%0, %1" : "=r" (v) : "0" (v)); 45 #else 46 uint32_t t1; 47 48 t1 = v ^ ((v << 16) | (v >> 16)); 49 t1 &= 0xff00ffffU; 50 v = (v >> 8) | (v << 24); 51 v ^= (t1 >> 8); 52 #endif 53 return (v); 54 } 55 56 #define __BYTE_SWAP_U16_VARIABLE __byte_swap_u16_variable 57 static __inline uint16_t 58 __byte_swap_u16_variable(uint16_t v) 59 { 60 61 #ifdef _ARM_ARCH_6 62 __asm("rev16\t%0, %1" : "=r" (v) : "0" (v)); 63 #elif !defined(__thumb__) 64 __asm volatile( 65 "mov %0, %1, ror #8\n" 66 "orr %0, %0, %0, lsr #16\n" 67 "bic %0, %0, %0, lsl #16" 68 : "=r" (v) 69 : "0" (v)); 70 #else 71 v &= 0xffff; 72 v = (v >> 8) | (v << 8); 73 #endif 74 75 return (v); 76 } 77 78 __END_DECLS 79 #endif 80 81 82 #endif /* _ARM_BYTE_SWAP_H_ */ 83