Division interfaces

Niels Möller nisse at lysator.liu.se
Mon Feb 28 22:59:17 CET 2011

What are the current plans for retiring the divrem_1 interface? IIRC, we
agreed there should be an interface more or less like

  div_qr_1 (mp_ptr qp, mp_limb_t *qh, mp_srcptr up, mp_size_t un,
	    mp_limb_t d);

and then preinv versions and separate functions for generating fraction

It would be easier to commit my new div_qr_1 code after this interface
change (if it's going to happen, that is).

And then we have the issue of unnormalized divisors (it looks like
mpn_sbpi1_div_qr still requires that dp[dn-1] has the high bit set. I'm
afraid that's going to be a bit of work. I think the strategy should be
to normalize high limbs (the inputs to the 3/2 division) on the fly, and
then do the book-keping needed when doing the mpn_submul_1 calls with
unnormalized arguments.


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