Perfect...thanks for the info. On Wednesday 27 June 2007 14:21, Satish Balay wrote: > On Wed, 27 Jun 2007, Tim Stitt 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). > > Rebuild a different variant of the libraires [with a different > PETSC_ARCH] using COPTFLAGS=-O3 FOPTFLAGS=-O3 > > > Ideally I would prefer a solution which doesn't involve rebuilding PETSc > > each time I want to switch the optimization level. > > You just build both versions once, and switch between them by switching > PETSC_ARCH > > make PETSC_ARCH=opt mybinary > make PETSC_ARCH=opt-3 mybinary > > > 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. > > If you are chaning config files manually, then you'll have to change > all occurances of -O in petscconf file [not petscrules]. Also - if > you've used --download-mpich, then mpicc etc wrappers would need > this modification aswell. > > So its best to build different variants of PETSc libraries with > different PETSC_ARCH values. > > Satish
-- 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)
