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From: mccalpin@perelandra.cms.udel.edu (John D. McCalpin)
Newsgroups: comp.sys.sgi
Subject: Minor f77 bug
Message-ID: <MCCALPIN.90Aug16112739@pereland.cms.udel.edu>
Date: 16 Aug 90 15:27:39 GMT
Sender: usenet@ee.udel.edu
Organization: College of Marine Studies, U. Del.
Lines: 35
Nntp-Posting-Host: perelandra.cms.udel.edu

I just found a minor bug related to over-zealous optimization.  It
seems that the optimizer does not notice that variables written out
using a NAMELIST have been accessed.  If they are not used anywhere
else, then they are silently deleted.

Therefore the following program (which I wrote to see what a NAMELIST
formatted file was supposed to look like) prints out all zeroes for
all of the namelist elements.  Dropping optimization back to -O0
resulted in the correct output.

	logical ident(4)
	namelist /inparms/	ident,ntmes,nrst,nplt,nrrec,nmud,stepsperday
	namelist /uparms/	saltup,saltdn,temptop,tempbot,transport

	saltup=10.
	saltdn=32.
	temptop=25.
	tempbot=25.
	transport=-400.
	stepsperday=360

	ntmes=3600
	nrst=1800
	nplt=1800
	nrrec=2
	nmud=360

	write(*,NML=inparms)
	write(*,NML=uparms)

	end
--
John D. McCalpin			mccalpin@perelandra.cms.udel.edu
Assistant Professor			mccalpin@vax1.udel.edu
College of Marine Studies, U. Del.	J.MCCALPIN/OMNET