| #include "Bitvec.h" |
| #include <vector> |
| #include <assert.h> |
| |
| // handle xnor |
| |
| typedef std::vector<uint32_t> slice; |
| typedef std::vector<slice> slice_vec; |
| |
| int countbits ( slice & v ) |
| { |
| int c = 0; |
| |
| for(size_t i = 0; i < v.size(); i++) |
| { |
| int d = countbits(v[i]); |
| |
| c += d; |
| } |
| |
| return c; |
| } |
| |
| int countxor ( slice & a, slice & b ) |
| { |
| assert(a.size() == b.size()); |
| |
| int c = 0; |
| |
| for(size_t i = 0; i < a.size(); i++) |
| { |
| int d = countbits(a[i] ^ b[i]); |
| |
| c += d; |
| } |
| |
| return c; |
| } |
| |
| void xoreq ( slice & a, slice & b ) |
| { |
| assert(a.size() == b.size()); |
| |
| for(size_t i = 0; i < a.size(); i++) |
| { |
| a[i] ^= b[i]; |
| } |
| } |
| |
| //----------------------------------------------------------------------------- |
| // Bitslice a hash set |
| |
| template< typename hashtype > |
| void Bitslice ( std::vector<hashtype> & hashes, slice_vec & slices ) |
| { |
| const int hashbytes = sizeof(hashtype); |
| const int hashbits = hashbytes * 8; |
| const int slicelen = ((int)hashes.size() + 31) / 32; |
| |
| slices.clear(); |
| slices.resize(hashbits); |
| |
| for(int i = 0; i < (int)slices.size(); i++) |
| { |
| slices[i].resize(slicelen,0); |
| } |
| |
| for(int j = 0; j < hashbits; j++) |
| { |
| void * sliceblob = &(slices[j][0]); |
| |
| for(int i = 0; i < (int)hashes.size(); i++) |
| { |
| int b = getbit(hashes[i],j); |
| |
| setbit(sliceblob,slicelen*4,i,b); |
| } |
| } |
| } |
| |
| void FactorSlices ( slice_vec & slices ) |
| { |
| std::vector<int> counts(slices.size(),0); |
| |
| for(size_t i = 0; i < slices.size(); i++) |
| { |
| counts[i] = countbits(slices[i]); |
| } |
| |
| bool changed = true; |
| |
| while(changed) |
| { |
| int bestA = -1; |
| int bestB = -1; |
| |
| for(int j = 0; j < (int)slices.size()-1; j++) |
| { |
| for(int i = j+1; i < (int)slices.size(); i++) |
| { |
| int d = countxor(slices[i],slices[j]); |
| |
| if((d < counts[i]) && (d < counts[j])) |
| { |
| if(counts[i] < counts[j]) |
| { |
| bestA = j; |
| bestB = i; |
| } |
| } |
| else if(d < counts[i]) |
| { |
| //bestA = |
| } |
| } |
| } |
| } |
| } |
| |
| |
| void foo ( void ) |
| { |
| slice a; |
| slice_vec b; |
| |
| Bitslice(a,b); |
| } |