Present:        Alan Clarke         - Scicon

                Mike Dolbear        - BP International, London

                Chris Lazou         - ULCC

                Geoff Millard       - ERCC

                Mike Nunn           - CCTA

                L Schonfelder       - Liverpool University

                Steve Watkins       - UMIST

                Alan Wilson         - ICL

                John Wilson         - Leicester University


                Chairman            John Wilson

                                    Computer Laboratory

                                    University of Leicester


                                    LE1 7RH


                Secretary           Mike Nunn


                                    Riverwalk House

                                    157 Millbank


                                    SW1P 4RT

                Treasurer           Keith Normington

                                    Computer Centre

                                    Coventry (Lanchester) Polytechnic


                                    CV1 5PB


Apologies were received from D Vallance and K Normington.

2.      MINUTES OF PREVIOUS MEETING [18 June 1984]

The minutes were accepted.


        (i)   Draft BSI Standard document "Method of Specifying Requirements

              for FORTRAN Language Processors"

              The Chairman said this should have been released, but had heard

              no definite news.

       (ii)   Treasurer of BCS Fortran Specialist Group

              Mr T L van Raalte had resigned as Treasurer for personal reasons.

              The Group expressed their thanks for all the work he had

              performed so diligently. K Normington had agreed to take on

              the Treasurer's position in combination with his role as


      (iii)   BCS Specialist Group Board

              The meeting on 19 September would include a British Telecom


       (iv)   FORTRAN Forum 1985

              ANSI members attending the X3J3 meeting in Oxford in July 1985

              have said they would be happy to participate in a BCS FORTRAN

              Forum, assuming it followed immediately afterwards. This

              could most conveniently be held in London and for that

              purpose the Institute of Education has been booked on

              Monday 15 July 1985. John Reid (AERE, Harwell) will

              organise the speakers and the general content of the Form.

              John Wilson will control the initial arrangements. To make

              the Forum a success they could both do with some help. So

              they would be very pleased to hear from people willing to

              offer assistance in organising it.

              The Group anticipate 100-150 people will attend and a buffet

              lunch will be provided. The fee will be decided soon.

        (v)   The Chairman has been in correspondence with Mr D W Harding

              (Secretary General, BCS) on how to obtain better

              administrative support to our Group from BCS HQ.

       (vi)   Anyone with suggestions for topics for afternoon talks

              at future Fortran Specialist Group meetings should

              contact John Wilson.


       (i)    The Secretary distributed various papers received for

              perusal including:

              - The press release announcing that BCS now has a Royal


              - A programme for the Data Communication Specialist Group

              - Minutes received of the February X3J3 meeting in Austin.

      (ii)    British Telecom are organising a colloquium on December 3 on the

              topic of "IKBS - the path to user-friendly computers"

              (see appendix B).

5.      X3J3 PROGRESS

       (i)    A letter had been received from Mr D Payne (Director, CAD

              Centre) who felt certain dissatisfactions with the prospective

              content of F8X. This was discussed by the Group. In


              BIT data type - Lawrie Schonfelder who regularly attends X3J3

                              meetings, said the chances of getting this into

                              "8X" were slim. At ANSI meetings there had

                              been conflicting demands for this structure

                              and in any case implementation was tricky.

                              However, it was well known that a lot of

                              people were asking for a BIT data type.

              Event handling/recursion - John Wilson pointed out that these

                                         structures are already specified t0

                                         appear in 8X.

              File handling - Incompatibilities between operating systems gave

                              problems with defining named files.

It was agreed that Alan Wilson would pass the letter onto X3J3 and also

formulate a response to Mr Payne. (see Alan's letter in appendix C).

    (ii)      Alan Wilson and Lawrie Schonfelder, who regularly attend

              X3J3 meetings, gave an update on recent progress. The

              stage has been reached at which ANSI has switched gear

              from language design to documenting the new 8X standard.

              It has been decided to re-write the S7 specification

              document with a structure more suited to 8X. In the

              meantime the Fortran Information Bulletin, written by

              Jerrold Wagener which summarises 8X content, has appeared

              "unofficially" in ForTec newsletter. The idea behind FIB

              is that X3J3 want to tell the world at large "this is how

              we see 8X".

  (iii)       On the 8X array extensions front Alan indicated that the CRAY

              NFT compiler will include some of the new 8x array features

              well before the new standard appears. The forthcoming Eta GS1O

              machine is expected to do likewise.

[A report by John Reid on the August 1984 X3J3 meeting is in Appendix A.]


   (i)    Recent Fortran books to appear include:

          "Pascal for Fortran Programmers" - Perrott and Allison (Computer

                                                                   Science Press)

          A new version of McCracken - appearing soon

          "Effective Fortran 77" - Mike Metcalf (Oxford University Press)


The next meeting of the group will be held on Monday 10 December 1984 from

10.45 to 16.00 at BCS Headquarters. In the afternoon Dr David Bailey

will speak on "Mixed Fortran and Prolog".


In the afternoon Geoff Millard from Edinburgh Regional Computer Centre

gave a talk on the ICL Fortran 77 optimising compiler. A synopsis of

this appears in appendix D.



28 October 1984


To:           NAG, BCS, DAP, etc.

From:         John Reid

Date:         11 August 1984

Subject:      Report on X3J3 meeting at Jackson, 6-10 August 1984


[1] 9l(11)JKR-10(Roth) Position of an unconnected file.

[2] 87(12)JHM-5 Sl Questions.

[3] 90(*)JKR-5 Conformance to the standard.

[4] 90(*)JTM-l Proposed intra-language compatibility policy.

[5] 90(7)KWH-11 Pointers.

[6] 9l(2)JAMS-l Multitasking.

[7] 9O(7)KWH-l CONDITION/ENABLE proposal.

[8] 9l(6/7)JKR-4 The meaning of IN, OUT and INOUT.

l.      Summary

        There were no dramatic developments at this meeting. Most

of the time was spent on tidying-up proposals and the

consideration of potential deletions arising from the Boston

"hit-list". It is hoped that all sections of the reformatted

document will be written between this and the next meeting. The

S7 that results from this meeting's changes will be the last and

the new document will be called S8. Whether any major

outstanding proposals will be accepted (e.g. BIT, error handling,

pointers) is doubtful.

2.     Subcommittee organisation

        A new subcommittee structure will operate from the next

meeting, to correspond with sections of the final draft document

as follows:

Subgroup                        Sections

   14          1. Introduction

               2. Fortran terms and concepts

               3. Lexical elements

   15          4. Data types

               5. Data objects

   18          6. Expressions and assignment

   16          7. Execution control

               8. Input-output

               9. Format specification

   17         10. Program units

              11. Procedures

   18         12. Intrinsic procedures

   14         13. Entity scope, association and definition

              14. Deprecated features

        I will be vice-chairman of subgroup 17.

        The new subgroups will take responsibility for checking and

revising their sections. The new document will be called S8.

3.      Source form

        Jim Matheny's proposal to delete significant blanks failed 11-11

(on the chairman's casting vote). His proposal to delete multi-

statement lines failed 3-2l. His proposal to add column position

rules to the new source form for compatibility with the old form (not

attractive since retention of significant blanks prevents full

compatibility) failed 5-19. However a straw vote favoured (19-0-7)

extending the old source form to include features of the new source

form as far as possible. A proposal to include in an appendix

algorithms for converting between the two forms and to state that "the

source form selection is specified in a processor dependent manner"

passed 25-0. The proposal that a processor might determine the form

by examining source records was rejected (l-17-11), as was a proposal

for specific compiler directives (11-12). The proposal that a

standard-conforming processor must be able to accept records of length

132 as accepted (16-4).

        The proposal to allow <, <=, etc as alternatives to .LT., .LE.,

etc failed (11-12) . The counter arguments were that not all operators

could be treated this way and that <,> are more valuable as another -

kind of bracket pair.

        My proposal to permit underscores within constants to represent

blanks was passed (16-3). It was agreed that they should be allowed

for input-output too.

        My proposal to add an inquiry function to permit RECL to be

specified portably in OPEN statements was criticized for its

dependence on the I-O UNIT and for not allowing for the additional

space needed for control information. A straw vote (7-3-7) favoured

the functionality. I will present a fresh proposal at the next


4.      Input-output

        A proposal to add a "PROMPT=" specifier to the READ statement,

which would output a short prompt then start reading from the same

line, failed (6-14). The subgroup favoured another specifier that

would avoid automatic new lines at the beginning of any READ/WRITE pp

statement, and I promised to work on it. My proposal to specify this

in the OPEN statement was not favoured because of its big impact on

the language description and because of the greater flexibility of the

other approach.

        Because of Michael Roth's paper [1], Jim Matheny asked the

committee to reconsider his proposal [2] to interpret Fortran 77 as

specifying that the position of a sequential file on OPEN is at its

initial position. Opinions are strongly held on this topic since some

implementations do otherwise. A straw vote was against (5-12-5). Jim

agrees with Michael's ideas and will bring a fresh proposal to the

next meeting.

5.      Conformance

        My ideas [3] on conformance were discussed by the steering group

who agreed with me in respect of the static properties of the program

but not for run-time checks. This view was endorsed by the full

committee (static checks: 19-7-3; run-time checks 7-17-6) and I

agreed to write a proposal for the next meeting. This will not be

easy since the standard does not recognise the concept of a compiler

in order to permit interpretative systems.

6.      Intra-language compatibility

        There was a discussion of X3's draft proposed intra-language

compatibility policy [4]. This lays down guidelines for the

justification of language features in a revised standard that may give

conversion difficulties for programs written for systems conforming to

the previous standard. It will not affect Fortran 8x since X3J3 is

committed to keeping Fortran 77 as a subset, but it does have

implications for F9X. Some committee members felt that it was far too

demanding of scarce committee resources, but personally I support it.

Some detailed changes were suggested and it was endorsed (9-6-2).

7.      Array features

        I presented my personal proposal to delete OTHERWISE. A

modification to change the keyword to ELSEWHERE was passed (23-0) but

its deletion was not (2-19), though the chairman illustrated my case

by showing that she had misinterpreted the semantics.

        I also presented my personal proposal to ban many-one aliases

(created by the IDENTIFY statement) and received a straw vote of 3-8-19.

The chairman asked the committee to consider the issue prior to

my representation of the proposal at the next meeting.

        A proposal for an inquiry intrinsic to find out whether an

allocatable array is allocated was accepted (21-0). The array group

did not like the suggestion that the ALLOCATE statement should include

a "space left" specifier because of difficulties with respect to what

units should be used to measure the space and uncertainties over space

needed for indexing information. However a logical specifier to

indicate whether the allocation had succeeded was favoured (19-2-6).

        A proposal was accepted (23-0) to move from SHAPE to SIZE the

facility for inquiring about the size of a particular dimension of an


        The form of brackets for array constructors was discussed.

Given that .GT., .GE., etc remain, the angle brackets < > could be

used but were not favoured (5-20-l) probably because they would imply

very long-term non-use of ( , > for their mathematical meanings. Adding

the alternatives (/ and /) was accepted (22-0).

        Intrinsics for finding the locations of the minimum and maximum

elements of arrays were discussed but no firm proposal was available.

Similarly there was a discussion on adding INITIAL_VALUE arguments to

DOTPRODUCT and MATMUL to permit accurate calculation of residuals, but

again no firm proposal was available.

        My proposal to replace vector-valued subscripts by intrinsics

was not liked by the array subgroups. I will present this as a

personal proposal at the next meeting. In the many-one case, the

effect of assignment is currently processor-dependent. The full

committee considered this and straw voted in favour of disallowing

such an assignment (13-4-4).

        A proposal to split the facilities offered currently by RESHAPE

between two simpler functions that reshape an array and permute its

dimensions failed (9-12).

8.      Data types

        Jerry Wagener suggested that COMPLEX should be considered as an

intrinsic data type. This would not affect any of the present usage

but would regularize and thereby simplify the language. It would lead

to alternative means of accessing the parts (e.g. Z%REAL) and defining

constants (e.g. COMPLEX(l.,l.)). However, the idea was not favoured


        The possibility of restoring BIT data type, which is in S6 but

has been labeled as waiting for Fortran 9x, was considered. Simpler

features that might provide the functionality were considered by small

ad-hoc groups. I suggested a set of intrinsics based on holding sets

of bits in integer arrays, but the idea was felt to be too inelegant.

It is possible that a proposal for a bit type holding a single bit and

needing arrays to hold strings might be presented at the next meeting,

but it looks too late.

        A motion for deleting entity-oriented declarations was passed

(12-9). Opinion is clearly divided, but the subgroup has committed

itself to proposing further changes in this area so that all the

information about an object can be collected together . In particular,

a replacement for the INITIAL statement is needed, given that DATA is

deprecated. A four way straw favoured extending DATA (13) or

initialization within the TYPE statement (7) as opposed to two

alternatives for changing INITIAL (3 for the two together).

        Deletion of variant data types was not favoured (3-22-2).

        Kurt Hirchert made a further presentation in favour of his kind

of pointers [5] but has not worked this up to a proposal.

9.      Event handling and multitasking

        W. Knies made a proposal [6] in favour of extending the present

event-handling chapter of S7 to multi-tasking. Its impact on the

language is large and there are a number of details still to be

resolved, which makes it hard to_see how this can be included in

Fortran 8x. The proposal was rejected (5-11) but the following motion

passed (24-0): "X3J3 strongly supports continued work on events. If

there is not time, it will be considered as a language extension

module or a collateral standard". A similar motion having "events"

replaced by "multitasking" also passing (24-0).

        The option was expressed that multitasking is very important, but

that it is too early to standardize because many different approaches

are being considered.

        Kurt Hirchert presented his proposal [7] on error handling from

the last meeting, but the committee had clearly not given it

sufficient attention (straw vote 6-0-21).

10.     Control structures

        The committee was clearly divided over my proposal to add a

WHILE clause to the block DO statement, but the proposal passed (12-10).

Replacing commas by colons in the block DO statement was not

favoured (7-17) , nor was the_ idea of replacing the "n TIMES" syntax by

omission of the DO control variable (1-27-6).

        A proposal to delete the keyword INTERNAL from the INTERNAL

procedure statement passed (17-5) after an amendment to make the

keyword optional failed (6-14).

        A proposal to name control blocks by placing the name ahead of

the first statement of the block and followed by a colon was accepted

(17-4) after much discussion provoked by the similarity between the

new form of block names and labels.

        My proposal [8] to change the definition of IN, OUT and INOUT was

accepted. The main difference is that an IN or INOUT dummy argument

need not necessarily be defined on entry.

11.     Next meeting

        The next meeting will be extended by three days to allow

editorial work on the new standing document (S8). The pre-meeting

deadline (for receipt of papers in USA) is October 8.


[British TELECOM headed paper; too faint to be reproduced]

Mr J D Wilson


Computer Laboratory                                        11th October 1984

Leicester University



Dear Mr Wilson,

Please find enclosed details of a colloquium which I am organising

on behalf of the IEE. I am contacting the Special Interest groups

in the BCS, and affiliated organisations, as I feel that the topic

of the colloquium (IKBS - the path to user-friendly computers), may

well be of interest to its members. If the BCS FORTRAN Group

produces a newsletter I would be grateful if the colloquium could be

mentioned in it.

Many thanks.

Yours sincerely,

Miss C J Alexander


IKBS - The Path to User-Friendly Computers                December 3 (1984)

Organised by the IEE and co-sponsored by the                London

Ergonomics Society this colloquium will consist of        UK

seven presentations on aspects of the role which IKBS

techniques have to play in improving the usability of

the man-computer interface.

Mrs J Hall LS(CG) , The Institute of Electrical Engineers

Savoy Place, London WC2R OBL Tel: 01-240 1871 x330

(Venue: IEE, Savoy Place)


Mr. D. W. Payne

CADCentre Limited

High Cross

Madingley Road

Cambridge CB3 OHB


Dear Mr. Payne:

Thank you for your letter of 20th August 1984 concerning

the need for standardization in certain areas of FORTRAN

which you feel may be in danger of being overlooked in the

current FORTRAN 8X language.

The information we have been able to pass along to you on

FORTRAN 8X has not been comprehensive, but there is now

available a document that describes all the work done to


I enclose a copy of the joint ACM SIGNUM Newsletter and

ACM FORTEC Forum publication "Status of Work Toward Revision

of Programming Language Fortran" by Jerrold Wagener.

I believe that Jerry Wagener's document will answer to most

of your requirements, though perhaps not all: pointers and

bit data type are not included but are still under active

study. Recursion is there. Modules provide a powerful

include facility.

Your letter will be passed along to X3J3 at its November

1984 meeting.

Yours sincerely,

Alan Wilson

for British Computer Society Fortran

Specialists Working Group

15 October 1984



Edinburgh worked on the optimiser with guidance from ICL. They were influenced by

IBM's H level compiler. The design consisted of 3 phases:-

      phase 1     preparation       identification of blocks

                                    analysis of variable usage  (note all inner and

                                    topological analysis         outer loops)

      phase 2     optimisations     subsumption -   replace wherever

                                                    reference to a

                                                    variable the value

                                                    that is assigned to it

                                                    eg A=1.0         A=1.0

                                                       IF(X.EQ.A) -> IF(X.EQ.1.0)

                                    special case processing

                                    eg A * 2.0      -> A + A

                                       A/2          -> A * 0.5

                                       (A*B)+(A*C)  -> A * (B + C)

                                       A/B/C        -> A / (B * C)

                                       - A/constant -> A/(- constant)

                                       A ** - 2     -> 1/(A ** 2)

                                       common expression elimination

                                       backward movement

                                       strength reduction

                                       test replacement

                                       eliminate redundant tests

      phase 3     architectural mapping

                                       allocate temporaries

                                       guide register usage

                  Optimisation at all 3 levels is carried out at the Subroutine level.


(i)     Compile time using the optimising computer is about 2.5 times the

        non-optimising compiler

(ii)    Subjective views on competing optimising systems:

                    IBM and DEC VAX   - comprehensive optimising  capabilities

                    Prime             - limited set of optimisations

                    Perkin-Elmer      - offers global optimising

(iii)   Current benchmarks have shown the greatest optimising gains are from

                    - coding of array accesses in loops

                    - removal of invariant subscript calculations

                    - amalgamation of counting and subscript incrementing

Global optimisation offers most significant gains.

(iv)    Achieving 25 - 30% execution speed improvement would be near the top of

        what one would expect from an optimiser.

(v)     C is the right language for writing compilers in the future which need


(vi)    PERQ - PNX has better organised code than POS.

(vii)   Pricing policy for the new Fortran 77 optimising compiler is determined by ICL.