random.cc revision 5190
12SN/A/* 21762SN/A * Copyright (c) 2003-2005 The Regents of The University of Michigan 32SN/A * All rights reserved. 42SN/A * 52SN/A * Redistribution and use in source and binary forms, with or without 62SN/A * modification, are permitted provided that the following conditions are 72SN/A * met: redistributions of source code must retain the above copyright 82SN/A * notice, this list of conditions and the following disclaimer; 92SN/A * redistributions in binary form must reproduce the above copyright 102SN/A * notice, this list of conditions and the following disclaimer in the 112SN/A * documentation and/or other materials provided with the distribution; 122SN/A * neither the name of the copyright holders nor the names of its 132SN/A * contributors may be used to endorse or promote products derived from 142SN/A * this software without specific prior written permission. 152SN/A * 162SN/A * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 172SN/A * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 182SN/A * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 192SN/A * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 202SN/A * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 212SN/A * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 222SN/A * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 232SN/A * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 242SN/A * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 252SN/A * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 262SN/A * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 272665Ssaidi@eecs.umich.edu * 282665Ssaidi@eecs.umich.edu * Authors: Nathan Binkert 292665Ssaidi@eecs.umich.edu * Ali Saidi 302SN/A */ 312SN/A 324395Ssaidi@eecs.umich.edu#include "base/fenv.hh" 335190Ssaidi@eecs.umich.edu#include "base/intmath.hh" 345190Ssaidi@eecs.umich.edu#include "base/misc.hh" 3556SN/A#include "base/random.hh" 365190Ssaidi@eecs.umich.edu#include "sim/serialize.hh" 372SN/A 382SN/Ausing namespace std; 392SN/A 405190Ssaidi@eecs.umich.eduRandom::Random() 412SN/A{ 425190Ssaidi@eecs.umich.edu // default random seed taken from original source 435190Ssaidi@eecs.umich.edu init(5489); 442SN/A} 452SN/A 465190Ssaidi@eecs.umich.eduRandom::Random(uint32_t s) 472SN/A{ 485190Ssaidi@eecs.umich.edu init(s); 492SN/A} 502SN/A 515190Ssaidi@eecs.umich.eduRandom::Random(uint32_t init_key[], int key_length) 523483Ssaidi@eecs.umich.edu{ 535190Ssaidi@eecs.umich.edu init(init_key, key_length); 543483Ssaidi@eecs.umich.edu} 553483Ssaidi@eecs.umich.edu 565190Ssaidi@eecs.umich.eduRandom::~Random() 571954SN/A{ 585190Ssaidi@eecs.umich.edu} 593483Ssaidi@eecs.umich.edu 605190Ssaidi@eecs.umich.edu// To preserve the uniform random distribution between min and max, 615190Ssaidi@eecs.umich.edu// and allow all numbers to be represented, we generate a uniform 625190Ssaidi@eecs.umich.edu// random number to the nearest power of two greater than max. If 635190Ssaidi@eecs.umich.edu// this number doesn't fall between 0 and max, we try again. Anything 645190Ssaidi@eecs.umich.edu// else would skew the distribution. 655190Ssaidi@eecs.umich.eduuint32_t 665190Ssaidi@eecs.umich.eduRandom::genrand(uint32_t max) 675190Ssaidi@eecs.umich.edu{ 685190Ssaidi@eecs.umich.edu int log = ceilLog2(max); 695190Ssaidi@eecs.umich.edu int shift = (sizeof(uint32_t) * 8 - log); 705190Ssaidi@eecs.umich.edu uint32_t random; 715190Ssaidi@eecs.umich.edu 725190Ssaidi@eecs.umich.edu do { 735190Ssaidi@eecs.umich.edu random = genrand() >> shift; 745190Ssaidi@eecs.umich.edu } while (random > max); 755190Ssaidi@eecs.umich.edu 765190Ssaidi@eecs.umich.edu return random; 771954SN/A} 781954SN/A 791954SN/Auint64_t 805190Ssaidi@eecs.umich.eduRandom::genrand(uint64_t max) 811954SN/A{ 825190Ssaidi@eecs.umich.edu int log = ceilLog2(max); 835190Ssaidi@eecs.umich.edu int shift = (sizeof(uint64_t) * 8 - log); 845190Ssaidi@eecs.umich.edu uint64_t random; 853483Ssaidi@eecs.umich.edu 865190Ssaidi@eecs.umich.edu do { 875190Ssaidi@eecs.umich.edu random = (uint64_t)genrand() << 32 | (uint64_t)genrand(); 885190Ssaidi@eecs.umich.edu random = random >> shift; 895190Ssaidi@eecs.umich.edu } while (random > max); 905190Ssaidi@eecs.umich.edu 915190Ssaidi@eecs.umich.edu return random; 921954SN/A} 935190Ssaidi@eecs.umich.edu 945190Ssaidi@eecs.umich.eduvoid 955190Ssaidi@eecs.umich.eduRandom::serialize(const string &base, ostream &os) 965190Ssaidi@eecs.umich.edu{ 975190Ssaidi@eecs.umich.edu int length = N; 985190Ssaidi@eecs.umich.edu paramOut(os, base + ".mti", mti); 995190Ssaidi@eecs.umich.edu paramOut(os, base + ".length", length); 1005190Ssaidi@eecs.umich.edu arrayParamOut(os, base + ".data", mt, length); 1015190Ssaidi@eecs.umich.edu} 1025190Ssaidi@eecs.umich.edu 1035190Ssaidi@eecs.umich.eduvoid 1045190Ssaidi@eecs.umich.eduRandom::unserialize(const string &base, Checkpoint *cp, const string §ion) 1055190Ssaidi@eecs.umich.edu{ 1065190Ssaidi@eecs.umich.edu int length; 1075190Ssaidi@eecs.umich.edu 1085190Ssaidi@eecs.umich.edu paramIn(cp, section, base + ".mti", mti); 1095190Ssaidi@eecs.umich.edu paramIn(cp, section, base + ".length", length); 1105190Ssaidi@eecs.umich.edu if (length != N) 1115190Ssaidi@eecs.umich.edu panic("cant unserialize random number data. length != %d\n", length); 1125190Ssaidi@eecs.umich.edu 1135190Ssaidi@eecs.umich.edu arrayParamIn(cp, section, base + ".data", mt, length); 1145190Ssaidi@eecs.umich.edu} 1155190Ssaidi@eecs.umich.edu 1165190Ssaidi@eecs.umich.eduRandom random_mt; 117