X-Git-Url: https://git.donarmstrong.com/?p=rsem.git;a=blobdiff_plain;f=boost%2Frandom%2Fseed_seq.hpp;fp=boost%2Frandom%2Fseed_seq.hpp;h=85500400158fc0332d1dcd015fccb1ef790a82af;hp=0000000000000000000000000000000000000000;hb=2d71eb92104693ca9baa5a2e1c23eeca776d8fd3;hpb=da57529b92adbb7ae74a89861cb39fb35ac7c62d diff --git a/boost/random/seed_seq.hpp b/boost/random/seed_seq.hpp new file mode 100644 index 0000000..8550040 --- /dev/null +++ b/boost/random/seed_seq.hpp @@ -0,0 +1,118 @@ +/* boost random/seed_seq.hpp header file + * + * Copyright Steven Watanabe 2010 + * Distributed under the Boost Software License, Version 1.0. (See + * accompanying file LICENSE_1_0.txt or copy at + * http://www.boost.org/LICENSE_1_0.txt) + * + * See http://www.boost.org for most recent version including documentation. + * + * $Id: seed_seq.hpp 85813 2013-09-21 20:17:00Z jewillco $ + * + */ + +#ifndef BOOST_RANDOM_SEED_SEQ_HPP +#define BOOST_RANDOM_SEED_SEQ_HPP + +#include +#include +#include +#include +#include +#include +#include +#include + +#ifndef BOOST_NO_CXX11_HDR_INITIALIZER_LIST +#include +#endif + +namespace boost { +namespace random { + +/** + * The class @c seed_seq stores a sequence of 32-bit words + * for seeding a \pseudo_random_number_generator. These + * words will be combined to fill the entire state of the + * generator. + */ +class seed_seq { +public: + typedef boost::uint_least32_t result_type; + + /** Initializes a seed_seq to hold an empty sequence. */ + seed_seq() {} +#ifndef BOOST_NO_CXX11_HDR_INITIALIZER_LIST + /** Initializes the sequence from an initializer_list. */ + template + seed_seq(const std::initializer_list& il) : v(il.begin(), il.end()) {} +#endif + /** Initializes the sequence from an iterator range. */ + template + seed_seq(Iter first, Iter last) : v(first, last) {} + /** Initializes the sequence from Boost.Range range. */ + template + explicit seed_seq(const Range& range) + : v(boost::begin(range), boost::end(range)) {} + + /** + * Fills a range with 32-bit values based on the stored sequence. + * + * Requires: Iter must be a Random Access Iterator whose value type + * is an unsigned integral type at least 32 bits wide. + */ + template + void generate(Iter first, Iter last) const + { + typedef typename std::iterator_traits::value_type value_type; + std::fill(first, last, static_cast(0x8b8b8b8bu)); + std::size_t s = v.size(); + std::size_t n = last - first; + std::size_t t = + (n >= 623) ? 11 : + (n >= 68) ? 7 : + (n >= 39) ? 5 : + (n >= 7) ? 3 : + (n - 1)/2; + std::size_t p = (n - t) / 2; + std::size_t q = p + t; + std::size_t m = (std::max)(s+1, n); + value_type mask = 0xffffffffu; + for(std::size_t k = 0; k < m; ++k) { + value_type r1 = + *(first + k%n) ^ *(first + (k+p)%n) ^ *(first + (k+n-1)%n); + r1 = r1 ^ (r1 >> 27); + r1 = (r1 * 1664525u) & mask; + value_type r2 = r1 + + ((k == 0) ? s : + (k <= s) ? k % n + v[k - 1] : + (k % n)); + *(first + (k+p)%n) = (*(first + (k+p)%n) + r1) & mask; + *(first + (k+q)%n) = (*(first + (k+q)%n) + r2) & mask; + *(first + k%n) = r2; + } + for(std::size_t k = m; k < m + n; ++k) { + value_type r3 = + (*(first + k%n) + *(first + (k+p)%n) + *(first + (k+n-1)%n)) + & mask; + r3 = r3 ^ (r3 >> 27); + r3 = (r3 * 1566083941u) & mask; + value_type r4 = r3 - k%m; + *(first + (k+p)%n) ^= r3; + *(first + (k+q)%n) ^= r4; + *(first + k%n) = r4; + } + } + /** Returns the size of the sequence. */ + std::size_t size() const { return v.size(); } + /** Writes the stored sequence to iter. */ + template + void param(Iter out) { std::copy(v.begin(), v.end(), out); } +private: + std::vector v; +}; + +} +} + +#endif