1/* $NetBSD: byte_swap_2.S,v 1.6 2013/08/19 03:44:18 matt Exp $ */ 2 3/*- 4 * Copyright (c) 1999 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. 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#include <machine/asm.h> 33 34#if defined(_KERNEL) || defined(_STANDALONE) 35#define FUNC _C_LABEL(bswap16) 36#else 37#define FUNC _C_LABEL(__bswap16) 38#endif 39 40ENTRY(FUNC) 41#ifdef _ARM_ARCH_6 42 rev16 r0, r0 43#elif !defined(__thumb__) 44 and r1, r0, #0xff 45 mov r0, r0, lsr #8 46 orr r0, r0, r1, lsl #8 47#else 48 movs r2, #0xff 49 movs r1, r0 50 ands r1, r1, r2 51 lsls r1, r1, #8 52 lsrs r0, r0, #8 53 ands r0, r0, r2 54 orrs r0, r0, r1 55#endif 56 RET 57END(FUNC) 58#if BYTE_ORDER == LITTLE_ENDIAN 59STRONG_ALIAS(_C_LABEL(ntohs), FUNC) 60STRONG_ALIAS(_C_LABEL(htons), FUNC) 61#endif 62