xref: /netbsd-src/common/lib/libc/arch/alpha/gen/byte_swap_4.S (revision 267197ec1eebfcb9810ea27a89625b6ddf68e3e7)
1*267197ecSapb/* $NetBSD: byte_swap_4.S,v 1.3 2008/02/16 17:37:13 apb Exp $ */
237c9f0a6Schristos
337c9f0a6Schristos/*
437c9f0a6Schristos * Copyright (c) 1996 Carnegie-Mellon University.
537c9f0a6Schristos * All rights reserved.
637c9f0a6Schristos *
737c9f0a6Schristos * Author: Chris G. Demetriou
837c9f0a6Schristos *
937c9f0a6Schristos * Permission to use, copy, modify and distribute this software and
1037c9f0a6Schristos * its documentation is hereby granted, provided that both the copyright
1137c9f0a6Schristos * notice and this permission notice appear in all copies of the
1237c9f0a6Schristos * software, derivative works or modified versions, and any portions
1337c9f0a6Schristos * thereof, and that both notices appear in supporting documentation.
1437c9f0a6Schristos *
1537c9f0a6Schristos * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
1637c9f0a6Schristos * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
1737c9f0a6Schristos * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
1837c9f0a6Schristos *
1937c9f0a6Schristos * Carnegie Mellon requests users of this software to return to
2037c9f0a6Schristos *
2137c9f0a6Schristos *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
2237c9f0a6Schristos *  School of Computer Science
2337c9f0a6Schristos *  Carnegie Mellon University
2437c9f0a6Schristos *  Pittsburgh PA 15213-3890
2537c9f0a6Schristos *
2637c9f0a6Schristos * any improvements or extensions that they make and grant Carnegie the
2737c9f0a6Schristos * rights to redistribute these changes.
2837c9f0a6Schristos */
2937c9f0a6Schristos
3037c9f0a6Schristos#include <machine/asm.h>
3137c9f0a6Schristos
3237c9f0a6Schristos/*
3337c9f0a6Schristos * Byte-swap a 4-byte quantity.  (Convert 0x01234567 to 0x67452301.)
3437c9f0a6Schristos *
35*267197ecSapb * Argument is an unsigned 4-byte integer (uint32_t).
3637c9f0a6Schristos */
37987ddf0aSyamt#if defined(_KERNEL) || defined(_STANDALONE)
38987ddf0aSyamt#define	BSWAP32	bswap32
39987ddf0aSyamt#else /* defined(_KERNEL) || defined(_STANDALONE) */
40987ddf0aSyamt#define	BSWAP32	__bswap32
41987ddf0aSyamt#endif /* defined(_KERNEL) || defined(_STANDALONE) */
42987ddf0aSyamtLEAF(BSWAP32, 1)		/* a0 contains 0x01234567 */
4337c9f0a6SchristosXLEAF(htonl, 1)
4437c9f0a6SchristosXLEAF(ntohl, 1)
4537c9f0a6Schristos	insbl	a0, 3, t0	/* t0 = 0x67       */
4637c9f0a6Schristos	extbl	a0, 1, t1	/* t1 = 0x      45 */
4737c9f0a6Schristos	extbl	a0, 2, t2	/* t2 = 0x      23 */
4837c9f0a6Schristos	extbl	a0, 3, t3	/* t3 = 0x      01 */
4937c9f0a6Schristos	sll	t1, 16, t1	/* t1 = 0x  45     */
5037c9f0a6Schristos	sll	t2, 8, t2	/* t2 = 0x    23   */
5137c9f0a6Schristos	or	t3, t0, v0	/* v0 = 0x67    01 */
5237c9f0a6Schristos	or	t1, t2, t1	/* t1 = 0x  4523   */
5337c9f0a6Schristos	or	t1, v0, v0	/* v0 = 0x67452301 */
5437c9f0a6Schristos	RET
55987ddf0aSyamtEND(BSWAP32)
56