Compiler Optimization Override

Barry Smith bsmith at
Thu Oct 4 10:36:40 CDT 2007

  It seems the config/ options -COPTFLAGS, -CXXOPTFLAGS, -FOPTFLAGS 
work correctly. That is if you set them then the default optimization is turned
off and what you provide is used. This works with petsc-dev.

  If this does not work for someone please send configure.log so we can
resolve the problem.


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).
> 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.

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