Torbjörn, > this looks quite interesting, I'm looking forward for cycle numbers. > (I guess you target the case where the divisor is not invariant, otherwise > you might do some preprocessing to speed up the partial quotient > approximation.) > > The divisor is invariant in some sense when the quotient is more than > one limb, right?
yes it is. But I was thinking about many divisions with the same divisor (say 2n limbs divided by n limbs). In short we can divide preprocessing methods in two classes: 1) those with only O(1) preprocessing time, like the precomputation of an inverse of the 1 or 2 uppers limbs of the divisor 2) those with O(n) preprocessing time, like Svoboda division > Are you thinking of Svoboda division here? That's another possibility > for speeding up schoolbook division. yes, in Svoboda division the quotient selection is for free. But you still have to wait the end of the previous submul_1 (or submul_2) call to access the next quotient, whereas in mpn_mul_basecase all multipliers are known in advance. Does this makes a difference? Paul _______________________________________________ gmp-devel mailing list gmp-devel@gmplib.org https://gmplib.org/mailman/listinfo/gmp-devel
