xref: /titanic_51/usr/src/lib/libc/i386/sys/gettimeofday.s (revision c10c16dec587a0662068f6e2991c29ed3a9db943)
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	.file	"gettimeofday.s"
28
29#include "SYS.h"
30
31	ANSI_PRAGMA_WEAK(gettimeofday,function)
32
33/
34/  implements int gettimeofday(struct timeval *tp, void *tzp)
35/
36/	note that tzp is always ignored
37/
38
39	ENTRY(gettimeofday)
40/
41/	use long long gethrestime()
42/
43	SYSFASTTRAP(GETHRESTIME)
44/
45/	gethrestime trap returns seconds in %eax, nsecs in %edx
46/	need to convert nsecs to usecs & store into area pointed
47/	to by struct timeval * argument.
48/
49	movl 4(%esp), %ecx	/ put ptr to timeval in %ecx
50	jecxz 1f		/ bail if we get a null pointer
51	movl %eax, (%ecx)	/ store seconds into timeval ptr
52	movl $274877907, %eax	/ divide by 1000 as impl. by gcc
53	imull %edx		/ See Hacker's Delight pg 162
54	sarl $6, %edx		/ simplified by 0 <= nsec <= 1e9
55	movl %edx, 4(%ecx)	/ store usecs into timeval ptr + 4.
561:
57	RETC			/ return 0
58	SET_SIZE(gettimeofday)
59
60
61