[MPI3 Fortran] Proposed solution for the volatile buffer problem

Aleksandar Donev donev1 at llnl.gov
Wed Jan 14 17:41:37 CST 2009


Bill Long wrote:

> Remember the goal - to prevent code motion across the CALL.  Identifying 
> the CALL, almost by definition, is enough - it is just overkill.  I 
> covers all variables, including the ones you want to tag.  The price of 
> simplicity. 
The price, as Nick tried to explain to you, is that it kills other 
optimizations *throughout* the code, because the compilers has to assume 
worst-case scenarios. Not acceptable for a language like Fortran. We 
cannot trade simplicity for efficiency soo easily!

> The optimal solution would be to have both, and preferably 
> use the same keyword for the attribute and subroutine prefix.
OK, maybe that has potential.

Aleks



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