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/* Copyright (c) 1988 AT&T */ 28/* All Rights Reserved */ 29 30 .file "gettimeofday.s" 31 32/* 33 * C library -- gettimeofday 34 * int gettimeofday (struct timeval *tp); 35 */ 36 37#include "SYS.h" 38 39 ANSI_PRAGMA_WEAK(gettimeofday,function) 40 41/* 42 * The interface below calls the trap (0x27) to get the timestamp in 43 * secs and nsecs. It than converts the nsecs value into usecs before 44 * it returns. 45 * 46 * The algorithm used to perform the division by 1000 is based upon 47 * algorithms for division based upon multiplication by invariant 48 * integers. Relevant sources for these algorithms are: 49 * 50 * Granlund, T.; Montgomery, P.L.: "Division by Invariant Integers using 51 * Multiplication". SIGPLAN Notices, Vol. 29, June 1994, page 61. 52 * 53 * Magenheimer, D.J.; et al: "Integer Multiplication and Division on the HP 54 * Precision Architecture". IEEE Transactions on Computers, Vol 37, No. 8, 55 * August 1988, page 980. 56 * 57 * Steele G.; Warren H.: Hacker's Delight. 2002 Pearson Education, Ch 10 58 * 59 */ 60 61 ENTRY(gettimeofday) 62 brz,pn %o0, 1f 63 mov %o0, %o5 64 SYSFASTTRAP(GETHRESTIME) 65 stn %o0, [%o5] 66 sethi %hi(0x10624DD3), %o2 67 or %o2, %lo(0x10624DD3), %o2 68 mulx %o1, %o2, %o2 69 srlx %o2, 38, %o2 70 stn %o2, [%o5 + CLONGSIZE] 711: RETC 72 SET_SIZE(gettimeofday) 73