1/*
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2 * Copyright (c) 2014 ARM Limited 3 * All rights reserved 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * |
14 * Copyright (c) 2003-2005 The Regents of The University of Michigan 15 * All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions are 19 * met: redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer; 21 * redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution; 24 * neither the name of the copyright holders nor the names of its 25 * contributors may be used to endorse or promote products derived from 26 * this software without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 39 * 40 * Authors: Nathan Binkert 41 * Ali Saidi
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42 * Andreas Hansson |
43 */ 44
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32#include <limits>
33#include "base/fenv.hh"
34#include "base/intmath.hh"
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45#include <sstream> 46 |
47#include "base/misc.hh" 48#include "base/random.hh" 49#include "sim/serialize.hh" 50
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39using namespace std;
40
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51Random::Random() 52{
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43 // default random seed taken from original source
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53 // default random seed |
54 init(5489); 55} 56 57Random::Random(uint32_t s) 58{ 59 init(s); 60} 61
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52Random::Random(uint32_t init_key[], int key_length)
53{
54 init(init_key, key_length);
55}
56
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62Random::~Random() 63{ 64} 65
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61// To preserve the uniform random distribution between min and max,
62// and allow all numbers to be represented, we generate a uniform
63// random number to the nearest power of two greater than max. If
64// this number doesn't fall between 0 and max, we try again. Anything
65// else would skew the distribution.
66uint32_t
67Random::genrand(uint32_t max)
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66void 67Random::init(uint32_t s) |
68{
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69 if (max == 0)
70 return 0;
71 if (max == std::numeric_limits<uint32_t>::max())
72 return genrand();
73
74 int log = ceilLog2(max + 1);
75 int shift = (sizeof(uint32_t) * 8 - log);
76 uint32_t random;
77
78 do {
79 random = genrand() >> shift;
80 } while (random > max);
81
82 return random;
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69 gen.seed(s); |
70} 71
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85uint64_t
86Random::genrand(uint64_t max)
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72void 73Random::serialize(std::ostream &os) |
74{
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88 if (max == 0)
89 return 0;
90 if (max == std::numeric_limits<uint64_t>::max())
91 return genrand();
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75 panic("Currently not used anywhere.\n"); |
76
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93 int log = ceilLog2(max + 1);
94 int shift = (sizeof(uint64_t) * 8 - log);
95 uint64_t random;
96
97 do {
98 random = (uint64_t)genrand() << 32 | (uint64_t)genrand();
99 random = random >> shift;
100 } while (random > max);
101
102 return random;
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77 // get the state from the generator 78 std::ostringstream oss; 79 oss << gen; 80 std::string state = oss.str(); 81 paramOut(os, "mt_state", state); |
82} 83 84void
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106Random::serialize(const string &base, ostream &os)
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85Random::unserialize(Checkpoint *cp, const std::string §ion) |
86{
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108 int length = N;
109 paramOut(os, base + ".mti", mti);
110 paramOut(os, base + ".length", length);
111 arrayParamOut(os, base + ".data", mt, length);
112}
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87 panic("Currently not used anywhere.\n"); |
88
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114void
115Random::unserialize(const string &base, Checkpoint *cp, const string §ion)
116{
117 int length;
118
119 paramIn(cp, section, base + ".mti", mti);
120 paramIn(cp, section, base + ".length", length);
121 if (length != N)
122 panic("cant unserialize random number data. length != %d\n", length);
123
124 arrayParamIn(cp, section, base + ".data", mt, length);
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89 // the random generator state did not use to be part of the 90 // checkpoint state, so be forgiving in the unserialization and 91 // keep on going if the parameter is not there 92 std::string state; 93 if (optParamIn(cp, section, "mt_state", state)) { 94 std::istringstream iss(state); 95 iss >> gen; 96 } |
97} 98 99Random random_mt;
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