Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!apollo!rehrauer
From: rehrauer@apollo.HP.COM (Steve Rehrauer)
Newsgroups: comp.sys.apollo
Subject: Re: Bug in pas compiler
Message-ID: <4d6b224e.20b6d@apollo.HP.COM>
Date: 15 Oct 90 20:36:00 GMT
References: <9010151553.AB00336@apo.esiee.fr> <1990Oct15.194259.7815@engin.umich.edu>
Sender: root@apollo.HP.COM
Reply-To: rehrauer@apollo.HP.COM (Steve Rehrauer)
Organization: Hewlett-Packard Apollo Division - Chelmsford, MA
Lines: 33

In article <1990Oct15.194259.7815@engin.umich.edu> jal@acc (John Lauro) writes:
>In article <9010151553.AB00336@apo.esiee.fr> bonnetf@apo.esiee.fr (bonnet-franck) writes:
>>The result follows :
>>
>>bug.bin
>>         0
>>         1
>>
>>!!!
>>Has anyone an idea about that ? 
>>
>
>Ouch!  That's a nasty bug!

   Yes, it is.  Sigh.

>I just tested it, and the bug appears on the 10000 too.
>I was able to remove the bug by compiling with:
>   pas bug -opt 1
>(or -opt 0, which is no optimization.  The default is full or 4).

   Well, actually the default is 3.  -opt 4 turns on procedure-inlining
and relaxes some FORTRAN aliasing constraints, among other things.

   (And, I should mention that although -opt 0 turns off "high-level"
global optimizations, there's still some instruction-level optimization
happening.  If you really-by-gosh want the compilers to dork with your
code as little as possible, say -dba.  That disables durn near everything,
and is guaranteed to produce Real Dumb code.)
--
"I feel lightheaded, Sam.  I think my      | (Steve) rehrauer@apollo.hp.com
 brain is out of air.  But it's kind of    | The Apollo Systems Division of
 a neat feeling..." -- Freelance Police    |       Hewlett-Packard