SemiCRC - A fast CRC-like algorithm

' Evaluate the 16-bit Checksum of an array of bytes
Function SemiCRC(ByVal source() As Byte) As Integer
    Dim crc, temp As Integer, i As Long
    Const divisor As Integer = 32768

    For i = 0 To source.GetUpperBound(0)
        temp = 0
        If crc \ divisor Then temp = 1
        crc = (((crc * 2) And &HFFFF&) + temp) Xor CLng(source(i))
    Next

    Return crc
End Function