TODO for 5.2 v3

[Torbjorn Granlund]

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

  Torbjorn Granlund <tg at gmplib.org> writes:
  
  > * Make some other sec functions from Niels' list public?
  
  Here's a first patch adding a couple of other functions. Benchmarking
  and testing is missing (except that the sec_minvert tests still pass).
  
Thanks!

  One interface question: Return value of cnd_neg. Currently, the
  intention is that it should return output borrow if the condition is
  true, otherwise zero. Which means that it returns 1 iff cnd != 0 and x
  != 0. It's not clear if that's of any use. Maybe drop the return value?
  
The return value indeed seems pretty useless, but I am not sure.

A related issue is that we should be nervious about the leakyness of
plain type conditionals such as (cnd != 0) which we use for creating
masks and for forming the mpn_cnd_neg return value.  We might want to
require the cnd arguments to be either 0 or 1.  To some extent this
moves the problem to the caller, but often this will be less of a
problem there.  It may also very slightly reduce overhead.

Torbjörn