Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!wuarchive!texbell!texsun!newstop!sun!chiba!khb
From: khb@chiba.Sun.COM (Keith Bierman - SPD Advanced Languages)
Newsgroups: comp.sys.dec
Subject: Re: Fortran bug?
Keywords: fortran language f77 mod
Message-ID: <128675@sun.Eng.Sun.COM>
Date: 1 Dec 89 07:39:12 GMT
References: <7120@pt.cs.cmu.edu>
Sender: news@sun.Eng.Sun.COM
Reply-To: khb@sun.UUCP (Keith Bierman - SPD Advanced Languages)
Organization: Sun Microsystems, Mountain View
Lines: 41

In article <7120@pt.cs.cmu.edu> epperly@osnome.che.wisc.edu (Tom Epperly) writes:
>The following short fortran program gives a
>Fatal error in: /usr/lib/fcom1.31 Segmentation fault
>Nice error message!  I really don't know fortran, so I am not sure if this
>is a bug in the compiler or not.  Line seven is the line which causes the
>compiler to die(the one with the MOD).
>
>	PROGRAM test
>	IMPLICIT none
>	INTEGER level, igr
>	igr = 1
>	level = 2
>	igr = MOD(level,INT(10.0))
>	END
>
>Lastly, I am posting this for one of the users on our system; and I don't know
>why he wrote the MOD that way.
>

Runs fine on a sun4 with f77v1.3. The code is legal.


I assume this is a contrived example (cut down from something large no
doubt), as there is no file written (screen output) or anything else
to get a handle on ... so the compiler may try to optimize the whole
program away (default on 1.31 is -O1, if memory serves ... so you
might try -O0 for grins).

On a MIPS box with the current MIPS compilers the correct result is
also provided. Either this was a bug in the MIPS 1.31 compiler (which
DEC is still selling) or it was introduced as part of the the "port".

I'm afraid I don't have a DS3100 handy, so I can't provide a better
explaination nor a tested workaround.


Cheers
Keith H. Bierman    |*My thoughts are my own. !! kbierman@sun.com
It's Not My Fault   |	MTS --Only my work belongs to Sun* 
I Voted for Bill &  | Advanced Languages/Floating Point Group            
Opus                | "When the going gets Weird .. the Weird turn PRO"