random.hh revision 5190 
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;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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#ifndef __BASE_RANDOM_HH__
33#define __BASE_RANDOM_HH__
34
35#include <ios>
36#include <string>
37
38#include "base/range.hh"
39#include "sim/host.hh"
40
41class Checkpoint;
42
43class Random
44{
45  protected:
46    static const int N = 624;
47    static const int M = 397;
48    static const uint32_t MATRIX_A = (uint32_t)0x9908b0df;
49    static const uint32_t UPPER_MASK = (uint32_t)0x80000000;
50    static const uint32_t LOWER_MASK = (uint32_t)0x7fffffff;
51
52    uint32_t mt[N];
53    int mti;
54
55    uint32_t genrand();
56    uint32_t genrand(uint32_t max);
57    uint64_t genrand(uint64_t max);
58
59    void
60    _random(int8_t &value)
61    {
62        value = genrand() & (int8_t)-1;
63    }
64
65    void
66    _random(int16_t &value)
67    {
68        value = genrand() & (int16_t)-1;
69    }
70
71    void
72    _random(int32_t &value)
73    {
74        value = (int32_t)genrand();
75    }
76
77    void
78    _random(int64_t &value)
79    {
80        value = (int64_t)genrand() << 32 | (int64_t)genrand();
81    }
82
83    void
84    _random(uint8_t &value)
85    {
86        value = genrand() & (uint8_t)-1;
87    }
88
89    void
90    _random(uint16_t &value)
91    {
92        value = genrand() & (uint16_t)-1;
93    }
94
95    void
96    _random(uint32_t &value)
97    {
98        value = genrand();
99    }
100
101    void
102    _random(uint64_t &value)
103    {
104        value = (uint64_t)genrand() << 32 | (uint64_t)genrand();
105    }
106
107    // [0,1]
108    void
109    _random(float &value)
110    {
111        // ieee floats have 23 bits of mantissa
112        value = (genrand() >> 9) / 8388608.0;
113    }
114
115    // [0,1]
116    void
117    _random(double &value)
118    {
119        double number = genrand() * 2097152.0 + (genrand() >> 11);
120        value = number / 9007199254740992.0;
121    }
122
123
124    // Range based versions of the random number generator
125    int8_t
126    _random(int8_t min, int8_t max)
127    {
128        uint32_t diff = max - min;
129        return static_cast<int8_t>(min + genrand(diff));
130    }
131
132    int16_t
133    _random(int16_t min, int16_t max)
134    {
135        uint32_t diff = max - min;
136        return static_cast<int16_t>(min + genrand(diff));
137    }
138
139    int32_t
140    _random(int32_t min, int32_t max)
141    {
142        uint32_t diff = max - min;
143        return static_cast<int32_t>(min + genrand(diff));
144    }
145
146    int64_t
147    _random(int64_t min, int64_t max)
148    {
149        uint64_t diff = max - min;
150        return static_cast<int64_t>(min + genrand(diff));
151    }
152
153    uint8_t
154    _random(uint8_t min, uint8_t max)
155    {
156        uint32_t diff = max - min;
157        return static_cast<uint8_t>(min + genrand(diff));
158    }
159
160    uint16_t
161    _random(uint16_t min, uint16_t max)
162    {
163        uint32_t diff = max - min;
164        return static_cast<uint16_t>(min + genrand(diff));
165    }
166
167    uint32_t
168    _random(uint32_t min, uint32_t max)
169    {
170        uint32_t diff = max - min;
171        return static_cast<uint32_t>(min + genrand(diff));
172    }
173
174    uint64_t
175    _random(uint64_t min, uint64_t max)
176    {
177        uint64_t diff = max - min;
178        return static_cast<uint64_t>(min + genrand(diff));
179    }
180
181  public:
182    Random();
183    Random(uint32_t s);
184    Random(uint32_t init_key[], int key_length);
185    ~Random();
186
187    void init(uint32_t s);
188    void init(uint32_t init_key[], int key_length);
189
190    template <typename T>
191    T
192    random()
193    {
194        T value;
195        _random(value);
196        return value;
197    }
198
199    template <typename T>
200    T
201    random(T min, T max)
202    {
203        return _random(min, max);
204    }
205
206    template <typename T>
207    T
208    random(const Range<T> &range)
209    {
210        return _random(range.start, range.end);
211    }
212
213    // [0,1]
214    double
215    gen_real1()
216    {
217        return genrand() / 4294967296.0;
218    }
219
220    // [0,1)
221    double
222    gen_real2()
223    {
224        return genrand() / 4294967295.0;
225    }
226
227    // (0,1)
228    double
229    gen_real3()
230    {
231        return ((double)genrand() + 0.5) / 4294967296.0;
232    }
233
234  public:
235    void serialize(const std::string &base, std::ostream &os);
236    void unserialize(const std::string &base, Checkpoint *cp,
237                     const std::string &section);
238};
239
240extern Random random_mt;
241
242#endif // __BASE_RANDOM_HH__
243