random.hh

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/*
 * Copyright (c) 2014 ARM Limited
 * All rights reserved
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * 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
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 * this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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 */

/*
 * Mersenne twister random number generator.
 */

#ifndef __BASE_RANDOM_HH__
#define __BASE_RANDOM_HH__

#include <random>
#include <string>
#include <type_traits>

#include "base/compiler.hh"
#include "base/types.hh"
#include "sim/serialize.hh"

class Checkpoint;

class Random : public Serializable
{

  private:

    std::mt19937_64 gen;

  public:

    Random();
    Random(uint32_t s);
    ~Random();

    void init(uint32_t s);

    template <typename T>
    typename std::enable_if<std::is_integral<T>::value, T>::type
    random()
    {
        // [0, max_value] for integer types
        std::uniform_int_distribution<T> dist;
        return dist(gen);
    }

    template <typename T>
    typename std::enable_if<std::is_floating_point<T>::value, T>::type
    random()
    {
        // [0, 1) for real types
        std::uniform_real_distribution<T> dist;
        return dist(gen);
    }

    template <typename T>
    typename std::enable_if<std::is_integral<T>::value, T>::type
    random(T min, T max)
    {
        std::uniform_int_distribution<T> dist(min, max);
        return dist(gen);
    }

    void serialize(CheckpointOut &cp) const override;
    void unserialize(CheckpointIn &cp) override;
};

extern Random random_mt;

#endif // __BASE_RANDOM_HH__