xref: /titanic_52/usr/src/lib/libc/i386/sys/gettimeofday.s (revision b9bd317cda1afb3a01f4812de73e8cec888cbbd7)
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/*
23 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27#pragma ident	"%Z%%M%	%I%	%E% SMI"
28
29	.file	"%M%"
30
31#include "SYS.h"
32
33	ANSI_PRAGMA_WEAK(gettimeofday,function)
34
35/
36/  implements int gettimeofday(struct timeval *tp, void *tzp)
37/
38/	note that tzp is always ignored
39/
40
41	ENTRY(gettimeofday)
42/
43/	use long long gethrestime()
44/
45	SYSFASTTRAP(GETHRESTIME)
46/
47/	gethrestime trap returns seconds in %eax, nsecs in %edx
48/	need to convert nsecs to usecs & store into area pointed
49/	to by struct timeval * argument.
50/
51	movl 4(%esp), %ecx	/ put ptr to timeval in %ecx
52	jecxz 1f		/ bail if we get a null pointer
53	movl %eax, (%ecx)	/ store seconds into timeval ptr
54	movl $274877907, %eax	/ divide by 1000 as impl. by gcc
55	imull %edx		/ See Hacker's Delight pg 162
56	sarl $6, %edx		/ simplified by 0 <= nsec <= 1e9
57	movl %edx, 4(%ecx)	/ store usecs into timeval ptr + 4.
581:
59	RETC			/ return 0
60	SET_SIZE(gettimeofday)
61
62
63