[Getdp] getDP has 2 totally different convergence behaviors for the same input

[Cris]

Dear GetDP users,
 
I’ve found out why the 32 bits compiled versions behaves strange related to the convergence: It’s because the gcc compiler I used(gcc4.5.2), which is newer than the compiler used to generate the binnaries available on the GetDP site,(gcc4.1.2), behaves strange when I use -O2 optimization flag. 
My suposition was: the newer the gcc, the stranger behavior when using higher optimization level.
When using a smaller compiler optimization option (e.g: -O1) the issue is solved for the 32 bit situation – no convergence issue occurs. So I've solved my issue by compiling both petsc and getDP with the optimization flags "-g –O1 ".
 
Cheers,
Cris
 
--- On Wed, 3/23/11, Cris <cristina.sorina at yahoo.com> wrote:


From: Cris <cristina.sorina at yahoo.com>
Subject: getDP has 2 totally different convergence behaviors for the same input
To: getdp at geuz.org
Date: Wednesday, March 23, 2011, 1:11 PM







Dear GetDP users & developers, 
  
Please, please, please help me get in touch with somebody  who knows how the GetDP Linux binaries were compiled! 
My problem is: with the same GetDP input files I have 2 different behaviors for the GetDP tool: 
-          the GetDP versions compiled by me don’t converge (getdp-2.1.0-source.gz with: petsc-lite-3.1-p7.tar.gz, gsl-1.14, umfpack-5.4 on RedHat) 
-          the GetDP Linux binaries converge (getdp-2.1.0-source.gz) 
I’ve compiled GetDP with different petsc/gcc/compilation flags but the issue is always there – the iterations stop only when NL_NbrMaxIter is reached. 
 Possible causes: (could anyone confirm any of them?) 
- maybe some uninitialized flags in the getDP code are to be blamed, or the getDP different svn revision number for the getDP binnaries and the getDP compiled by me; 
- the strongest hunch: the compilation - I think that petsc/umfpack/gsl code versions might differ and that’s why the convergence is not achieved; 
- the gcc newer version compiler might optimize & behave differently. 
  
Please let me know if you could guide me towards someone who knows how the getDP Linux binaries were compiled? 
Did anyone have similar troubles? 
  
Many, many thanks, 
Cris 
 
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