xref: /onnv-gate/usr/src/lib/libc/amd64/sys/gettimeofday.s (revision 7298:b69e27387f74)
10Sstevel@tonic-gate/*
20Sstevel@tonic-gate * CDDL HEADER START
30Sstevel@tonic-gate *
40Sstevel@tonic-gate * The contents of this file are subject to the terms of the
56812Sraf * Common Development and Distribution License (the "License").
66812Sraf * You may not use this file except in compliance with the License.
70Sstevel@tonic-gate *
80Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
90Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing.
100Sstevel@tonic-gate * See the License for the specific language governing permissions
110Sstevel@tonic-gate * and limitations under the License.
120Sstevel@tonic-gate *
130Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each
140Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
150Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the
160Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying
170Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner]
180Sstevel@tonic-gate *
190Sstevel@tonic-gate * CDDL HEADER END
200Sstevel@tonic-gate */
216812Sraf
220Sstevel@tonic-gate/*
236812Sraf * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
240Sstevel@tonic-gate * Use is subject to license terms.
250Sstevel@tonic-gate */
260Sstevel@tonic-gate
27*7298SMark.J.Nelson@Sun.COM	.file	"gettimeofday.s"
280Sstevel@tonic-gate
296812Sraf#include "SYS.h"
300Sstevel@tonic-gate
310Sstevel@tonic-gate	ANSI_PRAGMA_WEAK(gettimeofday,function)
320Sstevel@tonic-gate
330Sstevel@tonic-gate/*
340Sstevel@tonic-gate *  implements int gettimeofday(struct timeval *tp, void *tzp)
350Sstevel@tonic-gate *
360Sstevel@tonic-gate *	note that tzp is always ignored
370Sstevel@tonic-gate */
380Sstevel@tonic-gate
396812Sraf	ENTRY(gettimeofday)
400Sstevel@tonic-gate/*
410Sstevel@tonic-gate *	use long long gethrestime()
420Sstevel@tonic-gate */
430Sstevel@tonic-gate	pushq	%rdi		/* pointer to timeval */
440Sstevel@tonic-gate	SYSFASTTRAP(GETHRESTIME)
450Sstevel@tonic-gate/*
460Sstevel@tonic-gate *	gethrestime trap returns seconds in %eax, nsecs in %edx
470Sstevel@tonic-gate *	need to convert nsecs to usecs & store into area pointed
480Sstevel@tonic-gate *	to by struct timeval * argument.
490Sstevel@tonic-gate */
500Sstevel@tonic-gate	popq	%rcx		/* pointer to timeval */
510Sstevel@tonic-gate	jrcxz	1f		/* bail if we get a null pointer */
520Sstevel@tonic-gate	movq	%rax, (%rcx)	/* store seconds into timeval ptr	 */
530Sstevel@tonic-gate	movl	$274877907, %eax	/* divide by 1000 as impl. by gcc */
540Sstevel@tonic-gate	imull	%edx		/* See Hacker's Delight pg 162 */
550Sstevel@tonic-gate	sarl	$6, %edx	/* simplified by 0 <= nsec <= 1e9 */
560Sstevel@tonic-gate	movq	%rdx, 8(%rcx)	/* store usecs into timeval ptr + 8. */
570Sstevel@tonic-gate1:
580Sstevel@tonic-gate	RETC			/* return 0 */
596812Sraf	SET_SIZE(gettimeofday)
600Sstevel@tonic-gate
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