From: dewar@merv.cs.nyu.edu (Robert Dewar)
Subject: Re: Renaming Fixed Point Mutiplicative operator in Ada 95
Date: 1998/05/21
Date: 1998-05-21T00:00:00+00:00 [thread overview]
Message-ID: <dewar.895785693@merv> (raw)
In-Reply-To: 01bd84c3$47215d60$440029a1@m00rq900
<<Multiplication was just an example of the compilation problem - division
is the REAL killer - how do you cope with divide-by-zero exceptions in
critical system when all you are allowed is the catch-all exception
handler, (and run-time checks switched off)? Terminating with an exception
is not an option when you are 2 miles above the Atlantic! I would prefer
to know EXACTLY what is going on in as much of the object code produced
than leave it to the whim of the compiler.
>>
Incidentally, in a critical system, I would jolly well hope that EITHER
a) you prove that division by zero cannot happen
or
b) you test for it explicitly
if z = 0 then
....
else
a := y /z;
end if;
Once again, I think this is way overblown. Incidentally, I find that having
the convention be that the compiler generates run time checks but you do
NOT permit exception handlers to be a diabolical one. Sounds like another
Ariane on the way. WHo on earth came up with that brilliant designed-to-
cause-trouble decision!
It is that decision that is causing you heartburn, and not surprisingly
so, rather than anything to do with redefining division!
next prev parent reply other threads:[~1998-05-21 0:00 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
1998-05-19 0:00 Renaming Fixed Point Mutiplicative operator in Ada 95 Stuart Hutchesson
1998-05-19 0:00 ` Matthew Heaney
1998-05-20 0:00 ` Robert Dewar
[not found] ` <matthew_heaney-ya023680002005981908570001@news.ni.net>
1998-05-21 0:00 ` John McCabe
1998-05-21 0:00 ` Robert Dewar
1998-05-21 0:00 ` Matthew Heaney
1998-05-21 0:00 ` Robert Dewar
1998-05-22 0:00 ` Robert I. Eachus
1998-05-23 0:00 ` Robert Dewar
[not found] ` <01bd84c3$47215d60$440029a1@m00rq900>
1998-05-21 0:00 ` Robert Dewar [this message]
1998-05-21 0:00 ` Simon Pilgrim
1998-05-21 0:00 ` Matthew Heaney
1998-05-22 0:00 ` Robert I. Eachus
1998-05-22 0:00 ` Stuart Hutchesson
1998-05-22 0:00 ` Matthew Heaney
1998-05-23 0:00 ` Robert Dewar
1998-05-22 0:00 ` Rod Chapman
1998-05-22 0:00 ` John McCabe
1998-05-21 0:00 ` Matthew Heaney
1998-05-21 0:00 ` Robert Dewar
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