Compiler Optimization Override

[Tim Stitt]

Hi Aron,

Thanks for the information...everything is clear now.

Hope you will be back to Ireland soon. Sure the weather can be miserable but 
nothing beats a good hike in the rain followed by a good pint of Guinness. 
Actually Guinness is pretty good with everything including PETSc coding :-)

Regards. 

On Wednesday 27 June 2007 14:19, Aron Ahmadia wrote:
> Dear Tim,
>
> I was just in Ireland a few weeks ago, had a great time climbing
> Carantouhil and the Pilgrim's Path :D
>
> Have you tried declaring a new $PETSC_ARCH and then overriding the
> optimization flags in ./conf/configure?  PETSc likes to use the
> $PETSC_ARCH flag to maintain all local builds under the same directory
> structure instead of the -prefix flags common to autoconf-style
> builds.
>
> Ideally you'd do something like this...
>
> declare -x PETSC_ARCH=petsc_linux_o3
> cd $PETSC_DIR
> ./config/configure.py --COPTFLAGS=-O3
> make
>
> If you want to build a debugging version as well, then type:
> declare -x PETSC_ARCH=petsc_debug
> ./config/configure.py --with-debugging=1
>
> you'll then be able to use PETSc makefiles to build your code as long
> as you declare your PETSC_ARCH and PETSC_DIR variables ahead of time.
>
> Let me know if this works!
> ~Aron
>
> On 6/27/07, Tim Stitt <timothy.stitt at ichec.ie> wrote:
> > Hi PETSc Users/Developers,
> >
> > Could someone explain how I can override the default optimization level
> > that comes with my PETSc build (currently -O). I want to set a more
> > aggressive optimization level (e.g. -O3) for my compiler (PathScale).
> >
> > Ideally I would prefer a solution which doesn't involve rebuilding PETSc
> > each time I want to switch the optimization level. I tried to add the
> > switch to the petscrules file but it always defaulted to the first
> > (lower?) optimization switch that appeared in the application compile
> > command line which seems to be built into PETSc.
> >
> > Any help gratefully received.
> >
> > Regards,
> >
> > Tim.
> >
> > --
> > Dr. Timothy Stitt <timothy_dot_stitt_at_ichec.ie>
> > HPC Application Consultant - ICHEC (www.ichec.ie)
> >
> > Dublin Institute for Advanced Studies
> > 5 Merrion Square - Dublin 2 - Ireland
> >
> > +353-1-6621333 (tel) / +353-1-6621477 (fax) / +353-874195427 (mobile)

-- 
Dr. Timothy Stitt <timothy_dot_stitt_at_ichec.ie>
HPC Application Consultant - ICHEC (www.ichec.ie)

Dublin Institute for Advanced Studies
5 Merrion Square - Dublin 2 - Ireland

+353-1-6621333 (tel) / +353-1-6621477 (fax) / +353-874195427 (mobile)