1/* $NetBSD: byte_swap_2.S,v 1.3 2008/02/16 17:37:13 apb Exp $ */ 2 3/* 4 * Copyright (c) 1996 Carnegie-Mellon University. 5 * All rights reserved. 6 * 7 * Author: Chris G. Demetriou 8 * 9 * Permission to use, copy, modify and distribute this software and 10 * its documentation is hereby granted, provided that both the copyright 11 * notice and this permission notice appear in all copies of the 12 * software, derivative works or modified versions, and any portions 13 * thereof, and that both notices appear in supporting documentation. 14 * 15 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 16 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 17 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 18 * 19 * Carnegie Mellon requests users of this software to return to 20 * 21 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 22 * School of Computer Science 23 * Carnegie Mellon University 24 * Pittsburgh PA 15213-3890 25 * 26 * any improvements or extensions that they make and grant Carnegie the 27 * rights to redistribute these changes. 28 */ 29 30#include <machine/asm.h> 31 32/* 33 * Byte-swap a 2-byte quantity. (Convert 0x0123 to 0x2301.) 34 * 35 * Argument is an unsigned 2-byte integer (uint16_t). 36 */ 37#if defined(_KERNEL) || defined(_STANDALONE) 38#define BSWAP16 bswap16 39#else /* defined(_KERNEL) || defined(_STANDALONE) */ 40#define BSWAP16 __bswap16 41#endif /* defined(_KERNEL) || defined(_STANDALONE) */ 42LEAF(BSWAP16, 1) /* a0 contains 0x0123 */ 43XLEAF(htons, 1) 44XLEAF(ntohs, 1) 45 insbl a0, 1, t0 /* t0 = 0x23 */ 46 extbl a0, 1, t1 /* t1 = 0x 01 */ 47 or t0, t1, v0 /* v0 = 0x2301 */ 48 RET 49END(BSWAP16) 50