xref: /titanic_41/usr/src/lib/libc/i386/gen/byteorder.s (revision 1402f64f9efa57c2c2cba776f3f45c67e6055deb)
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21/*
22 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 */
25
26	.file	"byteorder.s"
27
28#include "SYS.h"
29
30	/*
31	 * NOTE: htonl/ntohl are identical routines, as are htons/ntohs.
32	 * As such, they could be implemented as a single routine, using
33	 * multiple ALTENTRY/SET_SIZE definitions. We don't do this so
34	 * that they will have unique addresses, allowing DTrace and
35	 * other debuggers to tell them apart.
36	 */
37
38/	unsigned long htonl( hl )
39/	unsigned long ntohl( hl )
40/	long hl;
41/	reverses the byte order of 'long hl'
42/
43	ENTRY(htonl)
44	movl	4(%esp), %eax	/ %eax = hl
45	bswap	%eax		/ reverses the byte order of %eax
46	ret			/ return (%eax)
47	SET_SIZE(htonl)
48
49	ENTRY(ntohl)
50	movl	4(%esp), %eax	/ %eax = hl
51	bswap	%eax		/ reverses the byte order of %eax
52	ret			/ return (%eax)
53	SET_SIZE(ntohl)
54
55/	unsigned short htons( hs )
56/	short hs;
57/
58/	reverses the byte order in hs.
59/
60	ENTRY(htons)
61	movl	4(%esp), %eax	/ %eax = hs
62	bswap	%eax		/ reverses the byte order of %eax
63	shrl	$16, %eax	/ moves high 16-bit to low 16-bit
64	ret			/ return (%eax)
65	SET_SIZE(htons)
66
67	ENTRY(ntohs)
68	movl	4(%esp), %eax	/ %eax = hs
69	bswap	%eax		/ reverses the byte order of %eax
70	shrl	$16, %eax	/ moves high 16-bit to low 16-bit
71	ret			/ return (%eax)
72	SET_SIZE(ntohs)
73