xref: /titanic_52/usr/src/lib/libc/i386/sys/gettimeofday.s (revision 9a70fc3be3b1e966bf78825cdb8d509963a6f0a1)
17c478bd9Sstevel@tonic-gate/*
27c478bd9Sstevel@tonic-gate * CDDL HEADER START
37c478bd9Sstevel@tonic-gate *
47c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the
57257d1b4Sraf * Common Development and Distribution License (the "License").
67257d1b4Sraf * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate *
87c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate * and limitations under the License.
127c478bd9Sstevel@tonic-gate *
137c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
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177c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate *
197c478bd9Sstevel@tonic-gate * CDDL HEADER END
207c478bd9Sstevel@tonic-gate */
217257d1b4Sraf
227c478bd9Sstevel@tonic-gate/*
237257d1b4Sraf * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
247c478bd9Sstevel@tonic-gate * Use is subject to license terms.
257c478bd9Sstevel@tonic-gate */
267c478bd9Sstevel@tonic-gate
27*9a70fc3bSMark J. Nelson	.file	"gettimeofday.s"
287c478bd9Sstevel@tonic-gate
297257d1b4Sraf#include "SYS.h"
307c478bd9Sstevel@tonic-gate
317c478bd9Sstevel@tonic-gate	ANSI_PRAGMA_WEAK(gettimeofday,function)
327c478bd9Sstevel@tonic-gate
337c478bd9Sstevel@tonic-gate/
347c478bd9Sstevel@tonic-gate/  implements int gettimeofday(struct timeval *tp, void *tzp)
357c478bd9Sstevel@tonic-gate/
367c478bd9Sstevel@tonic-gate/	note that tzp is always ignored
377c478bd9Sstevel@tonic-gate/
387c478bd9Sstevel@tonic-gate
397257d1b4Sraf	ENTRY(gettimeofday)
407c478bd9Sstevel@tonic-gate/
417c478bd9Sstevel@tonic-gate/	use long long gethrestime()
427c478bd9Sstevel@tonic-gate/
437c478bd9Sstevel@tonic-gate	SYSFASTTRAP(GETHRESTIME)
447c478bd9Sstevel@tonic-gate/
457c478bd9Sstevel@tonic-gate/	gethrestime trap returns seconds in %eax, nsecs in %edx
467c478bd9Sstevel@tonic-gate/	need to convert nsecs to usecs & store into area pointed
477c478bd9Sstevel@tonic-gate/	to by struct timeval * argument.
487c478bd9Sstevel@tonic-gate/
497c478bd9Sstevel@tonic-gate	movl 4(%esp), %ecx	/ put ptr to timeval in %ecx
507c478bd9Sstevel@tonic-gate	jecxz 1f		/ bail if we get a null pointer
517c478bd9Sstevel@tonic-gate	movl %eax, (%ecx)	/ store seconds into timeval ptr
527c478bd9Sstevel@tonic-gate	movl $274877907, %eax	/ divide by 1000 as impl. by gcc
537c478bd9Sstevel@tonic-gate	imull %edx		/ See Hacker's Delight pg 162
547c478bd9Sstevel@tonic-gate	sarl $6, %edx		/ simplified by 0 <= nsec <= 1e9
557c478bd9Sstevel@tonic-gate	movl %edx, 4(%ecx)	/ store usecs into timeval ptr + 4.
567c478bd9Sstevel@tonic-gate1:
577c478bd9Sstevel@tonic-gate	RETC			/ return 0
587257d1b4Sraf	SET_SIZE(gettimeofday)
597c478bd9Sstevel@tonic-gate
607c478bd9Sstevel@tonic-gate
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