[petsc-dev] CFLAGS and COPTFLAGS

[Barry Smith]

On Jan 19, 2014, at 6:11 PM, Jed Brown <jed at jedbrown.org> wrote:

> Barry Smith <bsmith at mcs.anl.gov> writes:
> 
>>   Nope because in my previous assignment I asked Satish to check for
>>   -O stuff in compiler wrappers as well as CFLAGS.
> 
> So if a user builds with MPICH, they'll get different optimization
> options than building with Open MPI, simply because MPICH includes -O2
> in the wrapper?

   Yes.* 

    And BTW, you do know my opinion of compiler wrappers! 

   Barry

  * But note that we have not yet discussed the case where PETSc compilers the MPI implementation and what optimization flags we pass down there.

> 
>>> and some compilers have funny names for
>>> optimization flags.
>> 
>>   This is a small possibility because normally there is a -Od as well
>>   as the funny named other stuff. If we come upon another funny name
>>   that replaces -Od we can incorporate that as well.
> 
> I'm just not wild about being in the business of classifying which
> options are related to optimization.