Subject: HPFF Question.

From: [email-masked]
Date: Wed, 9 Jun 93 15:30:25 BST

Dear Sir/Madam,				        9th June '93

	     >>> Ref: DISTRIBUTION DIRECTIVES <<<

	I'm involved in developing a parallel program for
electromagnetic calculations on unstructured three dimensional
meshes. The basic sequential code is running and I'm working on
porting the code to a "general distributed memory" parallel 
machine. 

	To load balance the calculations the mesh is allocated
over the available processes using standard partitioning 
algorithms, in my case, Recursive Spectral Bisection. Anyway 
I'm at the position where I know where to allocate my unknowns. 
Using this information a "compiler" should be able to generate 
the correct message routines. Rather than coding this myself I 
wondered if HPF would be a practical option.

	My rough impression of HPF is that it's similar to
using "tiles" on the KSR1 where arrays are allocated in blocks,
or cyclically, over the available processors. This is similar to 
the !HPF$ DISTRIBUTE directive. This is ideal if you're working
on regular grids but no for unstructures meshes.
	
	 Well my main question is that can the DISTRIBUTE directive 
be used to allocate the array A(10), say over the processes so that

	Process 1 gets components  2,5,6,7
	Process 2                  1,3,4,8,9,10

using HPF directives? If not, will HPFF version 2.0 do it? Or
have I overlooked another directive.

Any help would be welcomed.
Paul.

----------------------------------------------------------------
			     Dr PJ Wesson
		       Oxford Parallel Programme
	        Oxford University Computing Laboratory
		     11 Keble Road. Oxford. OX1 3QD
		         +44 865 73839 (fax)
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