Bit blit routine, version 1

Torbjorn Granlund tg at
Wed Feb 4 19:13:00 CET 2004

Brian Hurt <bhurt at> 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.


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