Bit blit routine, version 1

[Torbjorn Granlund]

Brian Hurt <bhurt at spnz.org> writes:


  > We have mpn_lshift and mpn_rshift already in GMP, and they
  > are carefully optimized for all relevant processors.  They
  > implement what I mean with bit-blit.
  > 
  > In what way is your code different from mpn_lshift and mpn_rshift?
  > 
  > 
  
  My bitblit is a generalization of shift left/shift right routines.  I 
  forget what the problems I had were, but when I looked into doing rotates 
  with the current implementation of the shifts, I hit problems.
  
You should definitely use mpn_lshift and mpn_rshift to do
the actual O(n) work.  The first and last limbs will need special
handling, of course.

-- 
Torbjörn