Torbjorn Granlund <tg@gmplib.org> writes:

  We found a bug causing performance problems for numbers between 2^64 and
  2^127.  It could also trigger asserts with factoring numbers close to
  2^127.
  
  The new version is attached.

Another bug found, this time related to the GMP code.  It would clear
out an uninitialised structure with prime proving disabled.

Here ia a fixed version: