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Date: Sun, 9 Nov 1997 15:30:36 -0500 (EST)
From: Thomas David Rivers <rivers@dignus.com>
Message-Id: <199711092030.PAA08445@lakes.dignus.com>
To: freebsd-chat@freebsd.org, joerg_wunsch@uriah.heep.sax.de
Subject: Re: IDT processors?
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> As Alfred Perlstein wrote:
> 
> > sorry for the rant, anyone know where  can get a bug free chip? someone
> > has to be making them... :)
> 
> You're overly optimistic.  CPU bugs aren't anything new, and Intel
> doesn't have a copyright on them either. :-)
> 
> When i started doing Unix, this was with Data General's DG/UX,
> somewhere in 1991.  After some time, i was trying to debug a program
> that constantly behaved differently under the debugger than straight-
> through.  With quite a lot of effort, i had to find that the Motorola
> MC88000 CPU simply botched some flags when doing hardware (instruc-
> tion-level) tracing.  The result of some comparision has been marked
> `less than', `equal', and `greater then' at the same time. :-O
> 
> Motorola has fixed the bug in later revisions of their CPU.
> 
> Data General had even a builtin ``silicon filter'' in their compiler,
> to work around CPU bugs.  Maybe Thomas Rivers can tell us more about
> it...  i know he's been one of the principal gcc hackers with DG back
> in those days.
> 
> -- 
> cheers, J"org
> 

 Well - unfortunately I can't shed any light on that.  I was part
of a team doing 88k stuff separate from GCC.  We were tasked with
helping LPI (now Liant) getting their PL/1, COBOL, FORTRAN, etc... 
compilers running on the 88k.   The gcc stuff was done in a separate 
group.  I do know they did excellent work, though, thanks to the 
diligent efforts of a guy named Tom Wood.  I understand some of the 
more modern GCC improvements came from his efforts.
 
 Also, I left DG in Dec. '89; which is, unfortunately, before the time
we're talking about...  (I believe the first 'round of AViiONs had shipped, 
but nothing more before I left.)

	- Dave Rivers -