[petsc-dev] CFLAGS and COPTFLAGS

[Barry Smith]

On Jan 19, 2014, at 6:23 PM, Satish Balay <balay at mcs.anl.gov> wrote:

> On Sun, 19 Jan 2014, Jed Brown 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?
>> 
>>>> 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.
> 
> Perhaps swapping the order from '$CFLAGS $COPTFLAGS' to '$COPTFLAGS
> $CFLAGS' will suffice.

   No, this needs to be done right. Turn off PETSc setting optimization flags if mpicc or CFLAGS attempts to set them.

   Barry

> 
> Satish