1 files changed, 127 insertions, 0 deletions
diff --git a/Bitslice.cpp b/Bitslice.cpp
new file mode 100644
index 0000000..45a2249
--- /dev/null
+++ b/Bitslice.cpp
@@ -0,0 +1,127 @@
+#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);
+}
+\ No newline at end of file