> On May 26, 2015, at 2:14 AM, Jed Brown <[email protected]> wrote: > > Vijay Gopal Chilkuri <[email protected]> writes: >> So somehow the optimization flags effect the code execution !? >> is this a known issue ? > > Either your code is invalid (e.g., undefined behavior), numerically > unstable, or your vendor has a bug that you should report.
So first run with valgrind to find any memory issues http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind If/when that is clean slowly start putting back compiler optimization options (first just something like -O2) until you have a problem. Barry Optimization compiler flags are not all that common but do happen, though most of the time it is a user or PETSc bug
