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, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22/* Copyright (c) 1988 AT&T */ 23/* All Rights Reserved */ 24 25 26/* 27 * Copyright 2004 Sun Microsystems, Inc. All rights reserved. 28 * Use is subject to license terms. 29 */ 30 31#pragma ident "%Z%%M% %I% %E% SMI" 32 33 .file "%M%" 34 35/* 36 * C library -- gettimeofday 37 * int gettimeofday (struct timeval *tp); 38 */ 39 40#include <sys/asm_linkage.h> 41 42 ANSI_PRAGMA_WEAK(gettimeofday,function) 43 44#include "SYS.h" 45 46/* 47 * The interface below calls the trap (0x27) to get the timestamp in 48 * secs and nsecs. It than converts the nsecs value into usecs before 49 * it returns. 50 * 51 * The algorithm used to perform the division by 1000 is based upon 52 * algorithms for division based upon multiplication by invariant 53 * integers. Relevant sources for these algorithms are: 54 * 55 * Granlund, T.; Montgomery, P.L.: "Division by Invariant Integers using 56 * Multiplication". SIGPLAN Notices, Vol. 29, June 1994, page 61. 57 * 58 * Magenheimer, D.J.; et al: "Integer Multiplication and Division on the HP 59 * Precision Architecture". IEEE Transactions on Computers, Vol 37, No. 8, 60 * August 1988, page 980. 61 * 62 * Steele G.; Warren H.: Hacker's Delight. 2002 Pearson Education, Ch 10 63 * 64 */ 65 66 ENTRY(_gettimeofday) 67 brz,pn %o0, 1f 68 mov %o0, %o5 69 SYSFASTTRAP(GETHRESTIME) 70 stn %o0, [%o5] 71 sethi %hi(0x10624DD3), %o2 72 or %o2, %lo(0x10624DD3), %o2 73 mulx %o1, %o2, %o2 74 srlx %o2, 38, %o2 75 stn %o2, [%o5 + CLONGSIZE] 761: RETC 77 SET_SIZE(_gettimeofday) 78