[petsc-dev] CFLAGS and COPTFLAGS

[Barry Smith]

On Jan 19, 2014, at 5:50 PM, Jed Brown <jed at jedbrown.org> wrote:

> Barry Smith <bsmith at mcs.anl.gov> writes:
>>   User runs
>> 
>>     —with-cc=cc CFLAGS=“-m64” —with-debugging=0
>> 
>>   gets the same performance as
>> 
>>     —with-cc=cc CFLAGS=“-m64” —with-debugging=1
>> 
>>    Can’t understand why.
> 
> It wouldn't have quite the _same_ performance because of PETSc debugging
> overhead, but point taken.  OTOH, we may be squashing optimization flags
> internal to the wrappers

   Nope because in my previous assignment I asked Satish to check for -O stuff in compiler wrappers as well as CFLAGS.

> 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.

   Barry