thrust/random/linear_feedback_shift_engine.h

File members: thrust/random/linear_feedback_shift_engine.h

/*
 *  Copyright 2008-2013 NVIDIA Corporation
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

/*
 * Copyright Jens Maurer 2002
 *
 * Distributed under the Boost Software License, Version 1.0.
 * (See accompanying NOTICE file for the complete license)
 *
 * For more information, see http://www.boost.org
 */

#pragma once

#include <thrust/detail/config.h>

#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
#  pragma GCC system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
#  pragma clang system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
#  pragma system_header
#endif // no system header
#include <thrust/random/detail/linear_feedback_shift_engine_wordmask.h>
#include <thrust/random/detail/random_core_access.h>

#include <cstddef> // for size_t
#include <iostream>

THRUST_NAMESPACE_BEGIN

namespace random
{

template <typename UIntType, size_t w, size_t k, size_t q, size_t s>
class linear_feedback_shift_engine
{
public:
  // types

  using result_type = UIntType;

  // engine characteristics

  static const size_t word_size = w;

  static const size_t exponent1 = k;

  static const size_t exponent2 = q;

  static const size_t step_size = s;

private:
  static const result_type wordmask = detail::linear_feedback_shift_engine_wordmask<result_type, w>::value;
public:
  static const result_type min = 0;

  static const result_type max = wordmask;

  static const result_type default_seed = 341u;

  // constructors and seeding functions

  _CCCL_HOST_DEVICE explicit linear_feedback_shift_engine(result_type value = default_seed);

  _CCCL_HOST_DEVICE void seed(result_type value = default_seed);

  // generating functions

  _CCCL_HOST_DEVICE result_type operator()(void);

  _CCCL_HOST_DEVICE void discard(unsigned long long z);

private:
  result_type m_value;

  friend struct thrust::random::detail::random_core_access;

  _CCCL_HOST_DEVICE bool equal(const linear_feedback_shift_engine& rhs) const;

  template <typename CharT, typename Traits>
  std::basic_ostream<CharT, Traits>& stream_out(std::basic_ostream<CharT, Traits>& os) const;

  template <typename CharT, typename Traits>
  std::basic_istream<CharT, Traits>& stream_in(std::basic_istream<CharT, Traits>& is);

}; // end linear_feedback_shift_engine

template <typename UIntType_, size_t w_, size_t k_, size_t q_, size_t s_>
_CCCL_HOST_DEVICE bool operator==(const linear_feedback_shift_engine<UIntType_, w_, k_, q_, s_>& lhs,
                                  const linear_feedback_shift_engine<UIntType_, w_, k_, q_, s_>& rhs);

template <typename UIntType_, size_t w_, size_t k_, size_t q_, size_t s_>
_CCCL_HOST_DEVICE bool operator!=(const linear_feedback_shift_engine<UIntType_, w_, k_, q_, s_>& lhs,
                                  const linear_feedback_shift_engine<UIntType_, w_, k_, q_, s_>& rhs);

template <typename UIntType_, size_t w_, size_t k_, size_t q_, size_t s_, typename CharT, typename Traits>
std::basic_ostream<CharT, Traits>&
operator<<(std::basic_ostream<CharT, Traits>& os, const linear_feedback_shift_engine<UIntType_, w_, k_, q_, s_>& e);

template <typename UIntType_, size_t w_, size_t k_, size_t q_, size_t s_, typename CharT, typename Traits>
std::basic_istream<CharT, Traits>&
operator>>(std::basic_istream<CharT, Traits>& is, linear_feedback_shift_engine<UIntType_, w_, k_, q_, s_>& e);

} // namespace random

// import names into thrust::
using random::linear_feedback_shift_engine;

THRUST_NAMESPACE_END

#include <thrust/random/detail/linear_feedback_shift_engine.inl>