Hi all, Anton Mellit reported a bug in flint's heuristic GCD code which was hit in the wild.
Anton also supplied a working patch for this issue, which we applied to our code. After generating lots of examples quite similar to Anton's, we also discovered another very subtle, very rare bug, which could also account for the original issue. That bug is hard to describe with few words, but essentially when bit packing we were not adding a bit for signed coefficients. The original code took notice of this, but the accommodation that had been made for this fact was not quite correct. Both bugs were only triggered extremely rarely. I have applied both of these fixes to flint/trunk and flint/2.4 in our repository and have issued a new bugfix release, flint-2.4.5, available on our website http://flintlib.org/ I have tested the fixes for some hours with hardened test code, including a regression test for the original issue, and found no further failures. However, I have no access to any 32 bit machines. It would be nice, for peace of mind, if someone with access to a 32 bit machine could test that the code works there too. The sequence of commands should be something like: wget http://mpir.org/mpir-2.7.0-alpha12.tar.bz2 wget http://www.mpfr.org/mpfr-current/mpfr-3.1.2.tar.bz2 wget http://flintlib.org/flint-2.4.5.tar.gz tar -xvf mpir-2.7.0-alpha12.tar.bz2 tar -xvf mpfr-3.1.2.tar.bz2 tar -xvf flint-2.4.5.tar.gz cd mpir-2.7.0 ./configure --enable-gmpcompat make -j cd ../mpfr-3.1.2 ./configure --with-gmp-build=/home/username/mpir-2.7.0 make -j cd ../flint2 ./configure --with-mpir=/home/username/mpir-2.7.0 --with-mpfr=/home/username/mpfr-3.1.2 make -j make check MOD=fmpz_poly Bill. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
