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
