C implementation of mod_1_1

Torbjorn Granlund tg at gmplib.org
Tue Mar 1 13:46:37 CET 2011

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

  nisse at lysator.liu.se (Niels Möller) writes:
  > Could also be an error in the computations before mpq_get_d. I suspect
  > the difference in exponent between "last" and "new" is unexpected (one
  > could examine the printouts to see if its mpq_get_d gave a sensible
  > result or not, I think, but I can't do that at the moment).
  A quick check with pari's rational -> float conversion indicates that
  "new" is a correct conversion of the rational A. 
  So the bug is most likely trigged by the code adding EPS to A.
This bug is triggered by a recent change, but not necessarily your
division changes.

It is not triggered by every invocation of tests/mpq/t-get_d, some
seeding is needed.  That means that the bug might have been undetected
for a few days.

The bug is triggered both on gcc52 and gcc42, which provide slightly different
gcc compiler releases (4.3.3 vs 4.3.1).


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