| /* |
| * Copyright (c) 2003-2005 The Regents of The University of Michigan |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer; |
| * redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution; |
| * neither the name of the copyright holders nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| * Authors: Nathan Binkert |
| * Ali Saidi |
| */ |
| |
| #include <limits> |
| #include "base/fenv.hh" |
| #include "base/intmath.hh" |
| #include "base/misc.hh" |
| #include "base/random.hh" |
| #include "sim/serialize.hh" |
| |
| using namespace std; |
| |
| Random::Random() |
| { |
| // default random seed taken from original source |
| init(5489); |
| } |
| |
| Random::Random(uint32_t s) |
| { |
| init(s); |
| } |
| |
| Random::Random(uint32_t init_key[], int key_length) |
| { |
| init(init_key, key_length); |
| } |
| |
| Random::~Random() |
| { |
| } |
| |
| // To preserve the uniform random distribution between min and max, |
| // and allow all numbers to be represented, we generate a uniform |
| // random number to the nearest power of two greater than max. If |
| // this number doesn't fall between 0 and max, we try again. Anything |
| // else would skew the distribution. |
| uint32_t |
| Random::genrand(uint32_t max) |
| { |
| if (max == 0) |
| return 0; |
| if (max == std::numeric_limits<uint32_t>::max()) |
| return genrand(); |
| |
| int log = ceilLog2(max + 1); |
| int shift = (sizeof(uint32_t) * 8 - log); |
| uint32_t random; |
| |
| do { |
| random = genrand() >> shift; |
| } while (random > max); |
| |
| return random; |
| } |
| |
| uint64_t |
| Random::genrand(uint64_t max) |
| { |
| if (max == 0) |
| return 0; |
| if (max == std::numeric_limits<uint64_t>::max()) |
| return genrand(); |
| |
| int log = ceilLog2(max + 1); |
| int shift = (sizeof(uint64_t) * 8 - log); |
| uint64_t random; |
| |
| do { |
| random = (uint64_t)genrand() << 32 | (uint64_t)genrand(); |
| random = random >> shift; |
| } while (random > max); |
| |
| return random; |
| } |
| |
| void |
| Random::serialize(const string &base, ostream &os) |
| { |
| int length = N; |
| paramOut(os, base + ".mti", mti); |
| paramOut(os, base + ".length", length); |
| arrayParamOut(os, base + ".data", mt, length); |
| } |
| |
| void |
| Random::unserialize(const string &base, Checkpoint *cp, const string §ion) |
| { |
| int length; |
| |
| paramIn(cp, section, base + ".mti", mti); |
| paramIn(cp, section, base + ".length", length); |
| if (length != N) |
| panic("cant unserialize random number data. length != %d\n", length); |
| |
| arrayParamIn(cp, section, base + ".data", mt, length); |
| } |
| |
| Random random_mt; |