Subject: Summary of March 31 HPFF WG-1 meeting

From: "Rex Page" <[email-masked]>
Date: Tue, 21 Apr 92 08:45:53 -0500

Meeting of HPFF Working Group 1
      Relationship of HPF to Existing Fortran Standards
                March 31, 1992 - NASA Ames

The relationship between the rules of storage sequence and
storage association in Fortran and notions of data distribution
in HPF occupied the bulk of the group's attention at this
meeting.  Rick Swift's proposal for classifying distributable
versus non-distributable arrays and COMMON blocks formed the
basis of the discussion.  The intent of the proposal is to
restrict the application of data distribution directives to
arrays that are not storage-associated with other data objects
(e.g., through equivalence or arrays reshaped across procedure
boundaries or differing COMMON declarations).

The group clarified the proposal's definition of distributable
COMMON blocks, confirmed the advisabilty of excluding CHARACTER
data and scalar variables from distributable COMMON, and decided
that the distribution properties of pointer types relates
primarily to the issue of redistribution under program control.
Consideration of the redistribution matter was deferred,
waiting for recommendations from Working Group 3.  Rick Swift
agreed to revise his proposal to reflect the ideas developed
during the meeting.

There was a brief discussion of comments of potential KSR users
on Fortran 90 (summarized by Bruce Knobe) and the position of
X3H5 on language bindings (reported by Bruce Leasure).  WG 1
arrived at no specific conclusions from this information, but
arrived at a consensus that the X3H5 binding position could
have gone the opposite direction, based on the evidence.
Therefore, the position probably derives primarily from the
inclinations of the X3H5 group.  The HPFF view of language
binding could easily take a different turn.

The remaining time during the meeting was devoted mostly to
discussing the HPF base language:  Fortran 77?  Fortran 90?
Restricted Fortran 90?  Two bindings?  Much of the discussion
focussed on the issue of which Fortran 90 features the HPF
specification should or would include.  The group agreed that
the HPF defining document should include a section listing
the facilities of Fortran 90 touched by HPF and a cross
listing of the HPF features relating to those facilities.

It would be premature to say, at this point, which Fortran 90
facilities would be involved.  Therefore, rather than making an
explicit recommendation on this issue now, the group is inclined
to encourage the HPF Forum to include in their proposals those
Fortran 90 elements that are relevant to the HPF features being
defined.  The Forum would then produce a cross listing of
HPF/Fortran 90 features at the end of the process.  

WG 1 agreed to meet in Dallas on the afternoon of April 22 to
put the final touches on its proposal regarding distributable
variables and its recommendation on HPF/Fortran bindings.

                          Report submitted by
                          Rex Page, ad hoc secretary, HPFF WG 1