Created
January 6, 2023 20:15
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lookahead bitset guard - ANDNZ
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#include <cstddef> | |
#include <initializer_list> | |
template<size_t BITS> | |
class bitset | |
{ | |
public: | |
bitset() : sizeInBits(BITS), sizeOfWord(sizeof(WORD) * 8), sizeInWords((BITS + (sizeof(WORD) * 8) - 1) / (sizeof(WORD) * 8)) { | |
for (size_t i = 0; i < sizeInWords; ++i) | |
data[i] = 0; | |
} | |
bitset(bitset<BITS>& bs) : bitset(bs.sizeInBits, bs.complement) { | |
for (size_t i = 0; i < sizeInWords; ++i) | |
data[i] = bs.data[i]; | |
} | |
bitset(const bitset<BITS>& bs) : bitset(bs.sizeInBits, bs.complement) { | |
for (size_t i = 0; i < sizeInWords; ++i) | |
data[i] = bs.data[i]; | |
} | |
bitset(const std::initializer_list<size_t> il) : bitset<BITS>() { | |
for (auto i = il.begin(); i != il.end(); ++i) | |
set(*i); | |
} | |
~bitset() {} | |
bitset& set(size_t element, bool v = true) { | |
size_t word = element / sizeOfWord; | |
size_t bit = element % sizeOfWord; | |
WORD value = ((WORD)1) << bit; | |
data[word] = (data[word] & ~value) | (v ? value : 0); | |
return *this; | |
} | |
template<size_t B> | |
friend inline bool AND(const bitset<B>& input, const bitset<B>& lookaheads) { | |
bool result = false; | |
for (size_t i = 0; i < lookaheads.sizeInWords; ++i) | |
result |= (input.data[i] & lookaheads.data[i]) != 0; | |
return result; | |
} | |
private: | |
typedef unsigned long long WORD; | |
const size_t sizeInBits; | |
const size_t sizeOfWord; | |
const size_t sizeInWords; | |
bool complement; | |
WORD data[(BITS + (sizeof(WORD) * 8) - 1) / (sizeof(WORD) * 8)]; | |
}; | |
int main(int argc, char *argv[]) { | |
bitset<63> input; | |
input.set(argc); | |
bitset<63> lookahead = {1, 3, 5}; | |
bool result = AND(input, lookahead) ? 0 : 1; | |
return result; | |
} |
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