Torbjorn Granlund tg at
Fri Dec 28 09:45:37 CET 2012

nisse at (Niels Möller) writes:

  bodrato at writes:
  > About mpz_combit code, may I suggest replacing the two lines
  > 	  MPN_NORMALIZE (dp, dsize);
  > 	  ASSERT (dsize > 0);
  > with
  > 	  MPN_NORMALIZE_NOT_ZERO (dp, dsize);
  > ?
  Conciseness is nice. Is that equivalent? I had some impression that the
  latter is less safe, but that may be completely wrong.
With --enable-assert, I think the alternative statements are equivalent.

Without --enable-assert, when dsize = 0, the former will scan zero limbs
and end up with dsize = 0, while the latter will scan into limbo.

If things go havoc for dsize = 0 for other reasons, then the two
variations will be effectively equivalent even without --enable-assert.


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