Possible bug in __gmpn_tdiv_qr

Torbjorn Granlund tg at gmplib.org
Fri Aug 7 13:08:14 CEST 2009

Michael Reilly <omnipotententity at gmail.com> writes:

  Hi there, I reached a backtrace while running a program, and I was
  wondering if I had uncovered a bug.
  There are really three things this could be:
  1) User error
  2) Computer error (RAM error maybe)
  3) Library error
  So I figured I'd do a dump here and let you know what I came across,
  and let you decide if it's my or my computer's fault.
  First the bt:
  *** glibc detected *** ./arithprogalgorithmic: double free or
  corruption (!prev): 0x0000000001ece700
  Next the output (program died about 6 days into calculation on my
  AMD64 X2) the full files are available if needed:

Six days, hmm.  I think I will not attempt to reproduce this.  Have you
tried running it again on the same computer and see if it fails
consistently?  If it does, it is less likely to be hardware problems.

If hardware problems are ruled out, it can be a bug in GMP, libc, your
code, or in the g++ libs...  Or perhaps you run out of memory?  You
should perhaps monitor a rerun to see if it uses more and more memory.

If you can reproduce the error consistently, and memory use remains
reasonable, then the first thing I'd do is trying to start the program
close to the failing point, in order to get a nicer turn around cycle.


More information about the gmp-bugs mailing list