performance improvement to tdiv_qr.c

[Torbjorn Granlund]

jweening at ccrwest.org (Joe Weening) writes:

  mpn/generic/tdiv_qr.c contains the following comment:
  
      /* In theory, we could fall out to the cute code below
         since we now have exactly the situation that code
         is designed to handle.  We botch this badly and call
         the basic mpn_sb_divrem_mn!  */
  
Thanks for the patch.  The development sources actually contains
a similar solution.

(We're rewriting the mpn division code for GMP 5, which will
make this code and mpn/tdiv_r.c go away.)

-- 
Torbjörn