CalcCRC

gistfile1.txt

var remainder = outputSpan.Length;
                ref var pointer = ref MemoryMarshal.GetReference(span);
                var currentCrc = (uint)0;

                while(remainder >= 4)
                {
                    var uintValue = Unsafe.As<byte, uint>(ref pointer);

                    currentCrc = System.Runtime.Intrinsics.X86.Sse42.Crc32(currentCrc, uintValue);
                    pointer = Unsafe.Add(ref pointer, 4);
                    remainder -= 4;
                }
                while(remainder > 0)
                {
                    currentCrc = System.Runtime.Intrinsics.X86.Sse42.Crc32(currentCrc, pointer);
                    pointer = Unsafe.Add(ref pointer, 1);
                    remainder -= 1;
                }

If i'm correct, to compute a CRC32C, currentCrc should be initialized with ~0U and set to ~currentCrc at the end