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add mersenne_twister generator C++14 version

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bolero-MURAKAMI 2015-04-05 22:43:50 +09:00
parent e85b8da5e1
commit bf3cc47c15
1 changed files with 90 additions and 2 deletions
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92
sprout/random/mersenne_twister.hpp
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@ -249,7 +249,7 @@ namespace sprout {
return rewind_1(data, last, z, x_[m - 1] ^ x_[n - 1]);
}
SPROUT_CONSTEXPR bool
equal_impl_2(mersenne_twister_engine const& other, sprout::array<result_type, n> back, std::size_t offset, std::size_t i = 0) const {
equal_impl_2(mersenne_twister_engine const& other, sprout::array<result_type, n> const& back, std::size_t offset, std::size_t i = 0) const {
return i < offset
? back[i + n - offset] != other.x_[i]
? false
@ -258,7 +258,7 @@ namespace sprout {
;
}
SPROUT_CONSTEXPR bool
equal_impl_1(mersenne_twister_engine const& other, sprout::array<result_type, n> back, std::size_t offset, std::size_t i = 0) const {
equal_impl_1(mersenne_twister_engine const& other, sprout::array<result_type, n> const& back, std::size_t offset, std::size_t i = 0) const {
return i + offset < n
? x_[i] != other.x_[i + offset]
? false
@ -372,6 +372,70 @@ namespace sprout {
SPROUT_CONSTEXPR mersenne_twister_engine twist() const {
return twist_1(0);
}
SPROUT_CXX14_CONSTEXPR void do_twist() {
UIntType const upper_mask = (~static_cast<UIntType>(0)) << r;
UIntType const lower_mask = ~upper_mask;
std::size_t const unroll_factor = 6;
std::size_t const unroll_extra1 = (n - m) % unroll_factor;
std::size_t const unroll_extra2 = (m - 1) % unroll_factor;
for (std::size_t j = 0; j < n - m - unroll_extra1; ++j) {
UIntType y = (x_[j] & upper_mask) | (x_[j + 1] & lower_mask);
x_[j] = x_[j+m] ^ (y >> 1) ^ ((x_[j + 1] & 1) * a);
}
for (std::size_t j = n - m - unroll_extra1; j < n-m; ++j) {
UIntType y = (x_[j] & upper_mask) | (x_[j + 1] & lower_mask);
x_[j] = x_[j + m] ^ (y >> 1) ^ ((x_[j + 1] & 1) * a);
}
for (std::size_t j = n - m; j < n - 1 - unroll_extra2; ++j) {
UIntType y = (x_[j] & upper_mask) | (x_[j + 1] & lower_mask);
x_[j] = x_[j - (n - m)] ^ (y >> 1) ^ ((x_[j + 1] & 1) * a);
}
for (std::size_t j = n - 1 - unroll_extra2; j < n - 1; ++j) {
UIntType y = (x_[j] & upper_mask) | (x_[j + 1] & lower_mask);
x_[j] = x_[j - (n - m)] ^ (y >> 1) ^ ((x_[j + 1] & 1) * a);
}
{
UIntType y = (x_[n - 1] & upper_mask) | (x_[0] & lower_mask);
x_[n - 1] = x_[m - 1] ^ (y >> 1) ^ ((x_[0] & 1) * a);
}
i_ = 0;
}
SPROUT_CXX14_CONSTEXPR void do_rewind(UIntType* last, std::size_t z) const {
UIntType const upper_mask = (~static_cast<UIntType>(0)) << r;
UIntType const lower_mask = ~upper_mask;
UIntType y0 = x_[m - 1] ^ x_[n - 1];
if (y0 & (static_cast<UIntType>(1) << (w - 1))) {
y0 = ((y0 ^ a) << 1) | 1;
} else {
y0 = y0 << 1;
}
for (std::size_t sz = 0; sz < z; ++sz) {
UIntType y1 = rewind_find(last, sz, m - 1) ^ rewind_find(last, sz, n - 1);
if (y1 & (static_cast<UIntType>(1) << (w - 1))) {
y1 = ((y1 ^ a) << 1) | 1;
} else {
y1 = y1 << 1;
}
*(last - sz) = (y0 & upper_mask) | (y1 & lower_mask);
y0 = y1;
}
}
SPROUT_CXX14_CONSTEXPR bool do_equal_impl(mersenne_twister_engine const& other) const {
UIntType back[n] = {};
std::size_t offset = other.i_ - i_;
for (std::size_t j = 0; j + offset < n; ++j) {
if (x_[j] != other.x_[j + offset]) {
return false;
}
}
do_rewind(&back[n - 1], offset);
for (std::size_t j = 0; j < offset; ++j) {
if (back[j + n - offset] != other.x_[j]) {
return false;
}
}
return true;
}
public:
SPROUT_CONSTEXPR mersenne_twister_engine()
: x_(init_seed(default_seed))
@ -388,12 +452,35 @@ namespace sprout {
SPROUT_CONSTEXPR result_type max() const SPROUT_NOEXCEPT {
return static_max();
}
SPROUT_CXX14_CONSTEXPR result_type operator()() {
if (i_ == n) {
do_twist();
}
UIntType z = x_[i_];
++i_;
z ^= ((z >> u) & d);
z ^= ((z << s) & b);
z ^= ((z << t) & c);
z ^= (z >> l);
return z;
}
SPROUT_CONSTEXPR sprout::random::random_result<mersenne_twister_engine> const operator()() const {
return i_ == n
? twist().generate()
: generate()
;
}
#ifndef SPROUT_CONFIG_DISABLE_CXX14_CONSTEXPR
friend SPROUT_CXX14_CONSTEXPR bool operator==(mersenne_twister_engine const& lhs, mersenne_twister_engine const& rhs) SPROUT_NOEXCEPT {
return lhs.i_ < rhs.i_
? lhs.do_equal_impl(rhs)
: rhs.do_equal_impl(lhs)
;
}
friend SPROUT_CXX14_CONSTEXPR bool operator!=(mersenne_twister_engine const& lhs, mersenne_twister_engine const& rhs) SPROUT_NOEXCEPT {
return !(lhs == rhs);
}
#else // #ifndef SPROUT_CONFIG_DISABLE_CXX14_CONSTEXPR
friend SPROUT_CONSTEXPR bool operator==(mersenne_twister_engine const& lhs, mersenne_twister_engine const& rhs) SPROUT_NOEXCEPT {
return lhs.i_ < rhs.i_
? lhs.equal_impl(rhs)
@ -403,6 +490,7 @@ namespace sprout {
friend SPROUT_CONSTEXPR bool operator!=(mersenne_twister_engine const& lhs, mersenne_twister_engine const& rhs) SPROUT_NOEXCEPT {
return !(lhs == rhs);
}
#endif // #ifndef SPROUT_CONFIG_DISABLE_CXX14_CONSTEXPR
template<typename Elem, typename Traits>
friend SPROUT_NON_CONSTEXPR std::basic_istream<Elem, Traits>& operator>>(
std::basic_istream<Elem, Traits>& lhs,