Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!rice!sun-spots-request
From: henley@athena.ee.msstate.edu (Greg Henley)
Newsgroups: comp.sys.sun
Subject: Fortran v1.2 optimization with SunOS 4.0.3?
Keywords: Software
Message-ID: <3761@brazos.Rice.edu>
Date: 4 Dec 89 15:17:23 GMT
Sender: root@rice.edu
Organization: Sun-Spots
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Approved: Sun-Spots@rice.edu
X-Sun-Spots-Digest: Volume 8, Issue 216, message 5 of 16

I recently obtained a 2000-3000 line CFD (Computational Fluid Dynamics)
program which was written in Fortran and which requires a considerable
amount of storage space and cpu time (approx. 65 meg and 2 hours to run
one cycle on a Sun 4/280). From previous experience on other C and Fortran
programs, full optimization could give a 2 to 3 times speedup.  However,
when I try optimization level -O2 or -O3, the program crashes with a huge
core dump. Level -O1 works but doesn't give any noticeable improvement in
execution time. We are running SunOS 4.0.3 and have Fortran version 1.2.
Has anyone else experienced this? If so, is there a bug fix? 

I was able to compile it on another Sun which was running SunOS 4.0 and
Fortran version 1.1. Level -O3 worked with no apparent problems and gave
about a 2 times speedup. Any help appreciated.

Greg Henley, Research Engineer
Mississippi State University
Dept. of Electrical Engineering
INET: henley@ee.msstate.edu