1/* 2 * Copyright (c) 2003-2005 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; --- 15 unchanged lines hidden (view full) --- 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Nathan Binkert 29 * Ali Saidi 30 */ 31 |
32#include "base/fenv.hh" |
33#include "base/intmath.hh" 34#include "base/misc.hh" |
35#include "base/random.hh" |
36#include "sim/serialize.hh" |
37 38using namespace std; 39 |
40Random::Random() |
41{ |
42 // default random seed taken from original source 43 init(5489); |
44} 45 |
46Random::Random(uint32_t s) |
47{ |
48 init(s); |
49} 50 |
51Random::Random(uint32_t init_key[], int key_length) |
52{ |
53 init(init_key, key_length); |
54} 55 |
56Random::~Random() |
57{ |
58} |
59 |
60// To preserve the uniform random distribution between min and max, 61// and allow all numbers to be represented, we generate a uniform 62// random number to the nearest power of two greater than max. If 63// this number doesn't fall between 0 and max, we try again. Anything 64// else would skew the distribution. 65uint32_t 66Random::genrand(uint32_t max) 67{ 68 int log = ceilLog2(max); 69 int shift = (sizeof(uint32_t) * 8 - log); 70 uint32_t random; 71 72 do { 73 random = genrand() >> shift; 74 } while (random > max); 75 76 return random; |
77} 78 79uint64_t |
80Random::genrand(uint64_t max) |
81{ |
82 int log = ceilLog2(max); 83 int shift = (sizeof(uint64_t) * 8 - log); 84 uint64_t random; |
85 |
86 do { 87 random = (uint64_t)genrand() << 32 | (uint64_t)genrand(); 88 random = random >> shift; 89 } while (random > max); 90 91 return random; |
92} |
93 94void 95Random::serialize(const string &base, ostream &os) 96{ 97 int length = N; 98 paramOut(os, base + ".mti", mti); 99 paramOut(os, base + ".length", length); 100 arrayParamOut(os, base + ".data", mt, length); 101} 102 103void 104Random::unserialize(const string &base, Checkpoint *cp, const string §ion) 105{ 106 int length; 107 108 paramIn(cp, section, base + ".mti", mti); 109 paramIn(cp, section, base + ".length", length); 110 if (length != N) 111 panic("cant unserialize random number data. length != %d\n", length); 112 113 arrayParamIn(cp, section, base + ".data", mt, length); 114} 115 116Random random_mt; |