Lucene.Net.Util.BitUtil.Pop_xor C# (CSharp) Метод

		public static long Pop_xor(long[] A, long[] B, int wordOffset, int numWords)
		{
			int n = wordOffset + numWords;
			long tot = 0, tot8 = 0;
			long ones = 0, twos = 0, fours = 0;
			
			int i;
			for (i = wordOffset; i <= n - 8; i += 8)
			{
				/***  C macro from Hacker's Delight
				#define CSA(h,l, a,b,c) \
				{unsigned u = a ^ b; unsigned v = c; \
				h = (a & b) | (u & v); l = u ^ v;}
				***/
				
				long twosA, twosB, foursA, foursB, eights;
				
				// CSA(twosA, ones, ones, (A[i] ^ B[i]), (A[i+1] ^ B[i+1]))
				{
					long b = (A[i] ^ B[i]), c = (A[i + 1] ^ B[i + 1]);
					long u = ones ^ b;
					twosA = (ones & b) | (u & c);
					ones = u ^ c;
				}
				// CSA(twosB, ones, ones, (A[i+2] ^ B[i+2]), (A[i+3] ^ B[i+3]))
				{
					long b = (A[i + 2] ^ B[i + 2]), c = (A[i + 3] ^ B[i + 3]);
					long u = ones ^ b;
					twosB = (ones & b) | (u & c);
					ones = u ^ c;
				}
				//CSA(foursA, twos, twos, twosA, twosB)
				{
					long u = twos ^ twosA;
					foursA = (twos & twosA) | (u & twosB);
					twos = u ^ twosB;
				}
				//CSA(twosA, ones, ones, (A[i+4] ^ B[i+4]), (A[i+5] ^ B[i+5]))
				{
					long b = (A[i + 4] ^ B[i + 4]), c = (A[i + 5] ^ B[i + 5]);
					long u = ones ^ b;
					twosA = (ones & b) | (u & c);
					ones = u ^ c;
				}
				// CSA(twosB, ones, ones, (A[i+6] ^ B[i+6]), (A[i+7] ^ B[i+7]))
				{
					long b = (A[i + 6] ^ B[i + 6]), c = (A[i + 7] ^ B[i + 7]);
					long u = ones ^ b;
					twosB = (ones & b) | (u & c);
					ones = u ^ c;
				}
				//CSA(foursB, twos, twos, twosA, twosB)
				{
					long u = twos ^ twosA;
					foursB = (twos & twosA) | (u & twosB);
					twos = u ^ twosB;
				}
				
				//CSA(eights, fours, fours, foursA, foursB)
				{
					long u = fours ^ foursA;
					eights = (fours & foursA) | (u & foursB);
					fours = u ^ foursB;
				}
				tot8 += Pop(eights);
			}
			
			
			if (i <= n - 4)
			{
				long twosA, twosB, foursA, eights;
				{
					long b = (A[i] ^ B[i]), c = (A[i + 1] ^ B[i + 1]);
					long u = ones ^ b;
					twosA = (ones & b) | (u & c);
					ones = u ^ c;
				}
				{
					long b = (A[i + 2] ^ B[i + 2]), c = (A[i + 3] ^ B[i + 3]);
					long u = ones ^ b;
					twosB = (ones & b) | (u & c);
					ones = u ^ c;
				}
				{
					long u = twos ^ twosA;
					foursA = (twos & twosA) | (u & twosB);
					twos = u ^ twosB;
				}
				eights = fours & foursA;
				fours = fours ^ foursA;
				
				tot8 += Pop(eights);
				i += 4;
			}
			
			if (i <= n - 2)
			{
				long b = (A[i] ^ B[i]), c = (A[i + 1] ^ B[i + 1]);
				long u = ones ^ b;
				long twosA = (ones & b) | (u & c);
				ones = u ^ c;
				
				long foursA = twos & twosA;
				twos = twos ^ twosA;
				
				long eights = fours & foursA;
				fours = fours ^ foursA;
				
				tot8 += Pop(eights);
				i += 2;
			}
			
			if (i < n)
			{
				tot += Pop((A[i] ^ B[i]));
			}
			
			tot += (Pop(fours) << 2) + (Pop(twos) << 1) + Pop(ones) + (tot8 << 3);
			
			return tot;
		}
		

        /// <summary>
        /// Returns the popcount or cardinality of the exclusive-or of the two sets.
        /// Neither set is modified.
        /// </summary>
        public static long XorCount(OpenBitSet a, OpenBitSet b)
        {
            long tot = BitUtil.Pop_xor(a.bits, b.bits, 0, Math.Min(a.Wlen, b.Wlen));

            if (a.Wlen < b.Wlen)
            {
                tot += BitUtil.Pop_array(b.bits, a.Wlen, b.Wlen - a.Wlen);
            }
            else if (a.Wlen > b.Wlen)
            {
                tot += BitUtil.Pop_array(a.bits, b.Wlen, a.Wlen - b.Wlen);
            }
            return(tot);
        }