Senior Checksum

crc32_senior.cs

public unsafe static uint ChecksumSenior(ReadOnlySpan<byte> arr)
{
    if (arr.Length == 0) return 0;
        
    fixed(byte* ptr = arr)
    {
        uint sum0 = 0, sum1 = 0, sum2 = 0, sum3 = 0;
        uint z = 0;

        var limit = arr.Length - 32;
        while (z < limit)
        {
            sum0 += (uint)(ptr[z + 0]  + ptr[z + 4]  + ptr[z + 8]  + ptr[z + 12]
                         + ptr[z + 16] + ptr[z + 20] + ptr[z + 24] + ptr[z + 28]);

            sum1 += (uint)(ptr[z + 1]  + ptr[z + 5]  + ptr[z + 9]  + ptr[z + 13]
                         + ptr[z + 17] + ptr[z + 21] + ptr[z + 25] + ptr[z + 29]);

            sum2 += (uint)(ptr[z + 2]  + ptr[z + 6]  + ptr[z + 10] + ptr[z + 14]
                         + ptr[z + 18] + ptr[z + 22] + ptr[z + 26] + ptr[z + 30]);

            sum3 += (uint)(ptr[z + 3]  + ptr[z + 7]  + ptr[z + 11] + ptr[z + 15]
                         + ptr[z + 19] + ptr[z + 23] + ptr[z + 27] + ptr[z + 31]);
            z += 32;
        }

        ...
    }
}