@tito_swineflu The lookup table is more complicated than that. The Pentium uses the SRT division algorithm, which does division in base 4, but allows the quotient digits to be -2, -1, 0, 1, or 2. The lookup table determines the quotient digit from the first few bits of the divisor and dividend so you don't need to completely divide. The quotient digit may not be completely accurate, but the negative values let you correct that in the next digit.