Parallel Fortran and PFA
Colin Brough
cmb at castle.ed.ac.uk
Wed Dec 12 00:56:44 AEST 1990
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 at castle.ed.ac.uk James Clerk Maxwell Building
cmb%ed.ac.uk at nsfnet-relay.ac.uk Mayfield Road
Edinburgh EH9 3JZ
Phone: +44 31-650-5022 SCOTLAND
Fax: +44 31-662-4712
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