div_qr_1 interface

[Torbjorn Granlund]

nisse at lysator.liu.se (Niels Möller) writes:

  > (3) Offet UP to avoid the offset in the loop.
  
  Should be straight forward. Or one could offset UN, but I think it's
  nice to be able to use dec / jnz for the loop.

There is plenty of execution bandwidth, so using 2 x lea, dec, jnz for
the loop control is no problem.  Only when one is decode (or dispatch,
retire) bandwidth constrained is indexing a good thing.

  Or is the obscure "loop" decrement and branch instruction useful?
  
I've hadrly ever used it.  IIRC, it can only reach -0x80..+0x7f from its
end.

-- 
Torbjörn