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Sprout/sprout/functional/fft/fixed/bitrev_table.hpp

64 lines
2 KiB
C++

#ifndef SPROUT_FUNCTIONAL_FFT_FIXED_BITREV_TABLE_HPP
#define SPROUT_FUNCTIONAL_FFT_FIXED_BITREV_TABLE_HPP
#include <cstddef>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/index_tuple.hpp>
#include <sprout/container/traits.hpp>
#include <sprout/container/functions.hpp>
#include <sprout/iterator/operation.hpp>
#include <sprout/algorithm/fixed/result_of.hpp>
#include <sprout/integer/bit_reverse.hpp>
#include <sprout/integer/bit_length.hpp>
namespace sprout {
namespace fixed {
namespace detail {
template<typename Container, sprout::index_t... Indexes>
SPROUT_CONSTEXPR inline typename sprout::fixed::result_of::algorithm<Container>::type bitrev_table_impl(
Container const& cont,
sprout::index_tuple<Indexes...>,
std::size_t bit_length,
typename sprout::container_traits<Container>::difference_type offset,
typename sprout::container_traits<Container>::size_type size
)
{
return sprout::remake<Container>(
cont,
sprout::size(cont),
(Indexes >= offset && Indexes < offset + size
? sprout::bit_reverse_in(
static_cast<typename sprout::container_traits<Container>::value_type>(Indexes - offset),
bit_length
)
: *sprout::next(sprout::internal_begin(cont), Indexes)
)...
);
}
} // namespace detail
//
// bitrev_table
//
template<typename Container>
SPROUT_CONSTEXPR inline typename sprout::fixed::result_of::algorithm<Container>::type bitrev_table(
Container const& cont
)
{
return sprout::fixed::detail::bitrev_table_impl(
cont,
typename sprout::index_range<0, sprout::container_traits<Container>::static_size>::type(),
sprout::empty(cont)
? 0
: sprout::bit_length(sprout::size(cont) - 1)
,
sprout::internal_begin_offset(cont),
sprout::size(cont)
);
}
} // namespace fixed
using sprout::fixed::bitrev_table;
} // namespace sprout
#endif // #ifndef SPROUT_FUNCTIONAL_FFT_FIXED_BITREV_TABLE_HPP