Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!oliveb!sun!chiba!khb
From: khb%chiba@Sun.COM (Keith Bierman - Sun Tactical Engineering)
Newsgroups: comp.lang.fortran
Subject: Re: Pointers in Fortran
Message-ID: <89276@sun.uucp>
Date: 10 Feb 89 09:31:10 GMT
References: <1328@dsacg3.UUCP> <7232@june.cs.washington.edu>
Sender: news@sun.uucp
Reply-To: khb@sun.UUCP (Keith Bierman - Sun Tactical Engineering)
Organization: Sun Microsystems, Mountain View
Lines: 41

In article <7232@june.cs.washington.edu> david@uw-june.UUCP (David Callahan) writes:
>From comp.software-eng,
>In article <1328@dsacg3.UUCP> vfm6066@dsacg3.UUCP (John A. Ebersold) writes:
>...

>I understand that Cray supports some flavor of pointer: integer
>variables can be used to define the base of an array. Sort-of C-ish
>really but without structures. Anyone have experience with
>these? Does the lack of typing on the variables used as pointers
>present a problem? Have other vendors provided pointer extensions?

Sun and DEC (among others) have both pointers and structures. Use of
pointers is _very_ bad for optimization. Personally I am not wild
about putting them in....since they are there they will be used...and
performance will suffer...then... well you get the picture.

>
>Fortran 8x has structures, but not pointers.
>
Wrong. Fortran88 (as ordained by WG5) has them. X3J3 has not produced
the ANSI equivalent of the WG5 document (sort of strange since X3J3
wrote the document which WG5 hath ordained...but life can be strange :>)


>I have heard it argued that "Fortran programmers need dynamically
>allocated arrays, not pointers", but that seems to me to
>be only one use for pointers. Does anyone know what some of the
>pointer proposals were?

Perhaps someone has the text(s) on line. I don't. You are correct that
dynamically allocated arrays are only one use (and one which does
_not_ require pointers!), however it is the _primary_ use in
scientific programs....and as mentioned above pointers cause
optimizers real, real, very bad, grief. 

cheers.

khb

Keith H. Bierman
It's Not My Fault ---- I Voted for Bill & Opus