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Date:      Wed, 30 Jul 1997 11:33:41 -0400
From:      Tod Luginbuhl <tod@science-guy.npt.nuwc.navy.mil>
To:        Sylvain Hubert <hubert@physics.uottawa.ca>
Cc:        freebsd-questions@FreeBSD.ORG
Subject:   Re: fortran compiler 
Message-ID:  <199707301533.LAA13403@SCIENCE-GUY.npt.nuwc.navy.mil>
In-Reply-To: Your message of "Tue, 29 Jul 1997 12:27:01 %2B0200." <19970729122701.26536@gil.physik.rwth-aachen.de> 

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On Fri, Jul 25, 1997 at 03:31:24PM -0400, Sylvain Hubert wrote:
>> Hi!
>> 
>> I am testing the f2c compiler on a PentiumPro (freeBSD OS) and
>> it seems that the optimization is not very efficient. It
>> might be because I do not use the proper options. I only try the
>> option -O3 for optimization.
>> 
>> Do someone knows how to optimize a fortan code for a Pentium Pro,
>> in other word, what options should I put?
>> 
>> Or, do someone knows of any good fortran compiler for a PentiumPro 
>> chip?
>> 
>> Thank you in advance for any reply!
>> 
>> Sylvain...
>

on Tue, 29 Jul 1997 12:27:01 +0200 Christoph Kukulies wrote:
>
>In what areas do you want to achieve optiimization? FP performance?
>Code size? Code speed?
>
>Optimizing for C is generally speaking also good for f77 (f2c).
>
>You might recompile libmsun with -DHAVE_FPU (/etc/make.conf).
>But beware of the consequences of loosing IEEE compliance.
>

Sylvain,

It may help you to get the technical report on f2c from Bell
Laboratories in the USA.  This report describes how various fortran
structures are translated to C.  This might help you understand the
optimization issues.  You can down load it from ftp.netlib.org.  The
file is in the f2c directory and is f2c.ps (login anonymously to
ftp.netlib.org, cd to f2c and get f2c.ps).

According to the FreeBSD website NAG is selling a Fortran 90 compiler
for FreeBSD.  The website for NAG is http://www.nag.co.uk.  I could not 
find a price for it on NAG's website.  I am very interested in this 
though.

You can also run Fortran compilers for Linux under FreeBSD's Linux
emulator.  You probably will need to run FreeBSD 2.2.x to get this to
work --- you need elf compatibility.  I'm currently doing this with
Absoft's Fortran 77 compiler for Linux under FreeBSD 2.2-stable.  This
works well for me, but Absoft's debugger does not work in the
emulator.  I have not played with the optimization.

I hope this helps you.

Tod

--------------------------------------------------------------------------

Tod Luginbuhl                             email:  t.e.luginbuhl@ieee.org
Code 2121
Naval Undersea Warfare Center             Telephone: (401) 841-7505 x38241
1176 Howell Street                        FAX:       (401) 841-7453
Newport, Rhode Island
USA

"Don't argue with drunks and fanatics!" -- Sun Wolf (Barbara Hambly)

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