random.cc (8658:f1a69b7246f7) random.cc (10349:939094c17866)
1/*
1/*
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 *
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

--- 12 unchanged lines hidden (view full) ---

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
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

--- 12 unchanged lines hidden (view full) ---

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
42 * Andreas Hansson
30 */
31
43 */
44
32#include <limits>
33#include "base/fenv.hh"
34#include "base/intmath.hh"
45#include <sstream>
46
35#include "base/misc.hh"
36#include "base/random.hh"
37#include "sim/serialize.hh"
38
47#include "base/misc.hh"
48#include "base/random.hh"
49#include "sim/serialize.hh"
50
39using namespace std;
40
41Random::Random()
42{
51Random::Random()
52{
43 // default random seed taken from original source
53 // default random seed
44 init(5489);
45}
46
47Random::Random(uint32_t s)
48{
49 init(s);
50}
51
54 init(5489);
55}
56
57Random::Random(uint32_t s)
58{
59 init(s);
60}
61
52Random::Random(uint32_t init_key[], int key_length)
53{
54 init(init_key, key_length);
55}
56
57Random::~Random()
58{
59}
60
62Random::~Random()
63{
64}
65
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)
66void
67Random::init(uint32_t s)
68{
68{
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;
69 gen.seed(s);
83}
84
70}
71
85uint64_t
86Random::genrand(uint64_t max)
72void
73Random::serialize(std::ostream &os)
87{
74{
88 if (max == 0)
89 return 0;
90 if (max == std::numeric_limits<uint64_t>::max())
91 return genrand();
75 panic("Currently not used anywhere.\n");
92
76
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;
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);
103}
104
105void
82}
83
84void
106Random::serialize(const string &base, ostream &os)
85Random::unserialize(Checkpoint *cp, const std::string &section)
107{
86{
108 int length = N;
109 paramOut(os, base + ".mti", mti);
110 paramOut(os, base + ".length", length);
111 arrayParamOut(os, base + ".data", mt, length);
112}
87 panic("Currently not used anywhere.\n");
113
88
114void
115Random::unserialize(const string &base, Checkpoint *cp, const string &section)
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);
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 }
125}
126
127Random random_mt;
97}
98
99Random random_mt;