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From: doug@escher.UUCP (Douglas J Freyburger)
Newsgroups: net.lang.f77,net.unix
Subject: Re: Wanted: Ultra-fast fortran compiler for UNIX
Message-ID: <40@escher.UUCP>
Date: Sat, 27-Jul-85 20:38:51 EDT
Article-I.D.: escher.40
Posted: Sat Jul 27 20:38:51 1985
Date-Received: Mon, 29-Jul-85 07:10:37 EDT
References: <621@astrovax.UUCP> <9871@Glacier.ARPA>
Distribution: net
Organization: NASA/JPL, Pasadena, CA
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Xref: watmath net.lang.f77:337 net.unix:5163

> >Can anyone point to a company that supplies a UNIX Fortran compiler which
> >executes much faster than f77 (say, on par with the VMS compilers or better)?
> 
> Actually there is limited room for improvement.  The 4.2BSD compiler is
> considerably better than the original f77 in that respect.  Published
> work (by Jack Dongarra at Argonne National Laboratory
> [dongarra@anl-mcs]) shows about 25-30% slower runtimes for the 4.2BSD
> compiler over the VMS 4.1 compiler, for dense linear algebra.  I've
> also coded some sparse linear algebra (essentially Yalepack) in
> assembly and found only 30-35% speed up.  Let's give credit where
> credit is due!
> 

I'm sorry, but I have troubles giving credit to a compiler
that is fully 30% slower than a competitors compiler for the
same machine architecture in the same language.  Does going
from blind translation into assembler really cost 30% more
execution time?  I always thought that good optimization was
less than that.  Does the Berkeley compiler do no
loop-invarient migration, common expression elimination or
ANYTHING?  It is true that DEC worked very hard optimizing
its ForTran's output, but 30%?  I haven't done ForTran work
on any on my unix machines yet, just C and Pascal, and this
makes me pretty happy about it.

Now I really understand the motivation behind the original
posting.  The only one I know about for unix is Green
Hills.  They have C, Pascal, ForTran (and P/LM?) for
assorted machines especially unix VAXen.

Doug Freyburger		DOUG@JPL-VLSI, DOUG@JPL-ROBOTICS
JPL 171-235		...escher!doug, doug@aerospace
Pasadena, CA 91106	etc.