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From: cmb@castle.ed.ac.uk (Colin Brough)
Newsgroups: comp.sys.sgi,comp.sys.sequent
Subject: Parallel Fortran and PFA
Keywords: Fortran, Parallel, preprocessor
Message-ID: <7542@castle.ed.ac.uk>
Date: 11 Dec 90 13:56:44 GMT
Sender: cmb@castle.ed.ac.uk
Organization: Edinburgh Parallel Computing Centre
Lines: 47

In the IRIS-4D Series FORTRAN 77 Programmer's Guide, section 5. FORTRAN
Enhancements for Multiprocessors, it states:

	"To provide compatibility for existing parallel programs,
	Silicon Graphics has chosen to adopt the syntax for parallelism
	used by Sequent Computer Corporation.  This syntax...."

Unfortunately the compiler directives subsequently described do not
match those described in the Sequent ATS Fortran User's Manual (ATS
Fortran version 1.0).  The SGI version has two extra options to the
DOACROSS directive, but is missing three in the Sequent version.  It
also has three extra directives, but is missing four directives that the
Sequent version supports.  i.e.

Both            Sequent         SGI
------------------------------------------------
C$DOACROSS-
 -SHARE          -LOCKS          -IF
 -LOCAL          -ORDER          -MP_SCHEDTYPE
 -LASTLOCAL      -UNROLL
 -REDUCTION
 -CHUNK
C$              C$LOCK          C$CHUNK
C$&             C$UNLOCK        C$MP_SCHEDTYPE
                C$ORDER         C$COPYIN
                C$ENDORDER

Have Sequent recently changed their syntax (ATS is their latest Fortran
compiler), or have SGI not actually implemented total compatability?

On a related topic, does the PFA parallel processing preprocessor only
produce code with a subset of these parallel processing directives in
it, or does it make use of them all?  In particular, I understand that
Kuck and Associates produce both PFA for SGI and the KAP preprocesor for
Sequent and I was wondering whether both these preprocessors used the
common subset of facilities provided by both SGI and Sequnet Parallel
Fortrans's.

Any information gratefully received.
__________________________________________________________________________
Colin Brough                           Edinburgh Parallel Computing Centre
cmb@castle.ed.ac.uk                    James Clerk Maxwell Building
cmb%ed.ac.uk@nsfnet-relay.ac.uk        Mayfield Road
                                       Edinburgh  EH9 3JZ
Phone: +44 31-650-5022                 SCOTLAND
Fax:   +44 31-662-4712
__________________________________________________________________________