81 lines
2.2 KiB
C++
81 lines
2.2 KiB
C++
#ifndef __CXXMPH_MPH_BITS_H__
|
|
#define __CXXMPH_MPH_BITS_H__
|
|
|
|
#include <stdint.h> // for uint32_t and friends
|
|
|
|
#include <array>
|
|
#include <cassert>
|
|
#include <climits>
|
|
#include <cmath>
|
|
#include <cstdio>
|
|
#include <cstring>
|
|
#include <limits>
|
|
#include <vector>
|
|
#include <utility>
|
|
|
|
namespace cxxmph {
|
|
|
|
class dynamic_2bitset {
|
|
public:
|
|
dynamic_2bitset();
|
|
~dynamic_2bitset();
|
|
dynamic_2bitset(uint32_t size, bool fill = false);
|
|
|
|
const uint8_t operator[](uint32_t i) const { return get(i); }
|
|
const uint8_t get(uint32_t i) const {
|
|
assert(i < size());
|
|
assert((i >> 2) < data_.size());
|
|
return (data_[(i >> 2)] >> (((i & 3) << 1)) & 3);
|
|
}
|
|
void set(uint32_t i, uint8_t v) {
|
|
assert((i >> 2) < data_.size());
|
|
data_[(i >> 2)] |= ones() ^ dynamic_2bitset::vmask[i & 3];
|
|
data_[(i >> 2)] &= ((v << ((i & 3) << 1)) | dynamic_2bitset::vmask[i & 3]);
|
|
assert(v <= 3);
|
|
assert(get(i) == v);
|
|
}
|
|
void resize(uint32_t size) {
|
|
size_ = size;
|
|
data_.resize(size >> 2, fill_*ones());
|
|
}
|
|
void swap(dynamic_2bitset& other) {
|
|
std::swap(other.size_, size_);
|
|
std::swap(other.fill_, fill_);
|
|
other.data_.swap(data_);
|
|
}
|
|
void clear() { data_.clear(); size_ = 0; }
|
|
|
|
uint32_t size() const { return size_; }
|
|
static const uint8_t vmask[];
|
|
const std::vector<uint8_t>& data() const { return data_; }
|
|
private:
|
|
uint32_t size_;
|
|
bool fill_;
|
|
std::vector<uint8_t> data_;
|
|
const uint8_t ones() { return std::numeric_limits<uint8_t>::max(); }
|
|
};
|
|
|
|
static uint32_t nextpoweroftwo(uint32_t k) {
|
|
if (k == 0) return 1;
|
|
k--;
|
|
for (uint32_t i=1; i<sizeof(uint32_t)*CHAR_BIT; i<<=1) k = k | k >> i;
|
|
return k+1;
|
|
}
|
|
// Interesting bit tricks that might end up here:
|
|
// http://graphics.stanford.edu/~seander/bithacks.html#ZeroInWord
|
|
// Fast a % (k*2^t)
|
|
// http://www.azillionmonkeys.com/qed/adiv.html
|
|
// rank and select:
|
|
// http://vigna.dsi.unimi.it/ftp/papers/Broadword.pdf
|
|
|
|
struct Ranktable { static uint8_t get(uint8_t); };
|
|
static uint8_t rank64(uint64_t bits) {
|
|
auto bytes = reinterpret_cast<const uint8_t*>(&bits);
|
|
return Ranktable::get(bytes[0]) + Ranktable::get(bytes[1]) +
|
|
Ranktable::get(bytes[2]) + Ranktable::get(bytes[3]);
|
|
};
|
|
|
|
} // namespace cxxmph
|
|
|
|
#endif
|