Mono.Math.BigInteger.Kernel.SquarePositive C# (CSharp) Method

			public static unsafe void SquarePositive (BigInteger bi, ref uint [] wkSpace)
			{
				uint [] t = wkSpace;
				wkSpace = bi.data;
				uint [] d = bi.data;
				uint dl = bi.length;
				bi.data = t;

				fixed (uint* dd = d, tt = t) {

					uint* ttE = tt + t.Length;
					// Clear the dest
					for (uint* ttt = tt; ttt < ttE; ttt++)
						*ttt = 0;

					uint* dP = dd, tP = tt;

					for (uint i = 0; i < dl; i++, dP++) {
						if (*dP == 0)
							continue;

						ulong mcarry = 0;
						uint bi1val = *dP;

						uint* dP2 = dP + 1, tP2 = tP + 2*i + 1;

						for (uint j = i + 1; j < dl; j++, tP2++, dP2++) {
							// k = i + j
							mcarry += ((ulong)bi1val * (ulong)*dP2) + *tP2;

							*tP2 = (uint)mcarry;
							mcarry >>= 32;
						}

						if (mcarry != 0)
							*tP2 = (uint)mcarry;
					}

					// Double t. Inlined for speed.

					tP = tt;

					uint x, carry = 0;
					while (tP < ttE) {
						x = *tP;
						*tP = (x << 1) | carry;
						carry = x >> (32 - 1);
						tP++;
					}
					if (carry != 0) *tP = carry;

					// Add in the diagnals

					dP = dd;
					tP = tt;
					for (uint* dE = dP + dl; (dP < dE); dP++, tP++) {
						ulong val = (ulong)*dP * (ulong)*dP + *tP;
						*tP = (uint)val;
						val >>= 32;
						*(++tP) += (uint)val;
						if (*tP < (uint)val) {
							uint* tP3 = tP;
							// Account for the first carry
							(*++tP3)++;

							// Keep adding until no carry
							while ((*tP3++) == 0x0)
								(*tP3)++;
						}

					}

					bi.length <<= 1;

					// Normalize length
					while (tt [bi.length-1] == 0 && bi.length > 1) bi.length--;

				}
			}