Article View: comp.lang.misc
Article #1347Re: Efficient Fortran
From: Steve Correll
Date: Tue, 17 Jul 1990 18:26
Date: Tue, 17 Jul 1990 18:26
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In article <138349@sun.Eng.Sun.COM>, lm@snafu.Sun.COM (Larry McVoy) writes:
> I have before me "Programmers Guide
> to Fortran 90" which contains things, such as pointers, that make me wonder
> if this is going to make fortran an uninteresting language.
In article <2306@l.cc.purdue.edu>, cik@l.cc.purdue.edu (Herman Rubin) writes:
> I understand that Fortran 90 is eliminating or restricting some of the useful,
> but not much used, features of Fortran considered bad by language gurus.
> The use of an ASSIGNED goto, especially without list, can make life
> difficult for the automatic optimizer, but it can sure speed up a program.
Be comforted. Fortran 90 does not eliminate or restrict any of the control
constructs of Fortran 77. The advocates of modernization bowed to a compromise
in which those constructs are merely deprecated and printed in small type.
The POINTER attribute is a more bizarre compromise which requires the
implementor to manipulate descriptors rather than mere addresses, but which
also requires the programmer to declare all target objects with a TARGET
attribute so as to limit the damage. If you never use the TARGET attribute,
the challenge confronting the optimizer is no worse than that of Fortran 77.
Regarding the merits of assigned GOTO, consider an architecture where the
address of an instruction cannot in fact be stored in an INTEGER variable
(because, for example, an address has 64 bits whereas an integer has 32).
--
...{sun,pyramid}!pacbell!key!sjc Steve Correll
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!know!zaphod.mps.ohio-state.edu!brutus.cs.uiuc.edu!apple!sun-barr!newstop!sun!amdahl!key!sjc From: sjc@key.COM (Steve Correll) Newsgroups: comp.lang.misc Subject: Re: Efficient Fortran Message-ID: <1991@key.COM> Date: 17 Jul 90 18:26:22 GMT References: <1990Jul3.194348.21178@msuinfo.cl.msu.edu> <9595@brazos.Rice.edu> <2306@l.cc.purdue.edu> Organization: Key Computer Labs, Fremont, CA Lines: 25