Article View: comp.lang.fortran
Article #4463Re: Fast I/O
From: Patrick F. McGehearty
Date: Fri, 22 Jan 1993 19:30
Date: Fri, 22 Jan 1993 19:30
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In article <1993Jan21.081105.4047@molene.ifremer.fr> molagnon@ditigo.ifremer.fr writes:
(revised for brevity):
Why don't compilers optimize I/O lists such as
write (lu) (a (j), j=1,n)
to be as fast as
write (lu) a
Convex Fortran does, and in the recent past, also added the optimization for:
write (lu) (a (j,i), j=1,n)
In my opinion, the answer to the question is that there is no technical
reason for compilers to not make this optimization. Rather it is a
question of resources and structural pressures. There are always more
potential optimizations and features to add to a language like Fortran
than there are resources to add them (Fortran 90 makes this statement
self-evident :-). If a compiler group has been entirely driven by the old
simple benchmarks such as Whetstones, Dhrystones, and Linpack 100x100,
they will not even realize that there is a worthwhile optimization to be
made in this case. If they use real production applications, then the
optimization may get on their to-do list, depending on their target market
segment.
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From: Patrick F. McGehearty <patrick@convex.COM>
Subject: Re: Fast I/O
Originator: patrick@wagner.convex.com
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Message-ID: <1993Jan22.193019.12936@news.eng.convex.com>
Date: Fri, 22 Jan 1993 19:30:19 GMT
Reply-To: patrick@convex.COM (Patrick F. McGehearty)
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