[Omp] Problems with optimisation

[Ruud van der Pas]

Hi Håkan,

> I get the following message when compiling with the f90 compiler and the -openmp option:
> 
> f90: Warning: Specify a supported level of optimization when using -xopenmp, -xopenmp will 
 > not set an optimization level in a future release. Optimization level changed to 3 to support -xopenmp.
> 
> I am suspecting that the automatic higher level of optimisation is bringing problems to my application. 
 > I am getting a nul pointer error even though the array is allocated in the calling routine. Is there any
 > way to get around this problem? There is nothing unusual with the code, and it seems that it needs to
 > run on a lower optimisation level. Thanks in advance.

To answer your question specifically, you can use -xopenmp=noopt

Using -xopenmp is a short cut for -xopenmp=parallel. This
enables optimization, but does require optimization level
-xO3 (as the message says), or higher.

I hope this solves the problem for now, but it is probably a good
idea to look into the null pointer problem you're running into.
There could be several reasons for this behavior.

Kind regards,
Ruud
----------------------------------------------------------------
Senior Staff Engineer             Email: ruud.vanderpas at sun.com
Systems Group                     Phone: +31-33-4515000 (x15920)
Sun Microsystems                  Fax  : +31-33-4515001
----------------------------------------------------------------