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From: rav@goanna.cs.rmit.edu.au (robin)
Subject: Re: fixed point vs floating point
Date: 1997/12/03
Date: 1997-12-03T00:00:00+00:00	[thread overview]
Message-ID: <6627vl$s4h$1@goanna.cs.rmit.edu.au> (raw)
In-Reply-To: dewar.881006262@merv


	dewar@merv.cs.nyu.edu (Robert Dewar) writes:


	>As to expecting the language to do scaling autoamtically, I think this is
	>a mistake for fixed-point. PL/1 tried and failed,

PL/I did not fail.  Automatic scaling of fixed-point intermediate
results is highly successful.  It works on the principle
of preserving as many digits after the binary/decimal point
as possible.

	> and COBOL certainly
	>does not succeed (a common coding rule in COBOL is never to use the
	>COMPUTE verb, precisely because the scaling is not well defined).

	>I think any attempt to automatically determine the scaling of intermediate
	>results in multiplications and divisions in fixed-point is doomed to failure.

It isn't really, but the user needs to understand how fixed-point
arithmetic -- with a fractional part -- works.

	>This just *has* to be left up to the programmer, since it is highly
	>implementation dependent.




  parent reply	other threads:[~1997-12-03  0:00 UTC|newest]

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
1997-11-22  0:00 fixed point vs floating point Matthew Heaney
1997-11-22  0:00 ` Tucker Taft
1997-11-22  0:00   ` Robert Dewar
1997-11-22  0:00     ` Matthew Heaney
1997-11-23  0:00 ` Geert Bosch
1997-11-23  0:00   ` Matthew Heaney
1997-11-23  0:00     ` Robert Dewar
1997-11-24  0:00       ` Herman Rubin
1997-11-24  0:00         ` Robert Dewar
1997-11-25  0:00           ` Joe Gwinn
1997-11-25  0:00             ` Robert Dewar
1997-11-25  0:00               ` Joe Gwinn
1997-11-25  0:00                 ` Robert Dewar
1997-11-26  0:00                   ` Joe Gwinn
1997-11-26  0:00                     ` Robert Dewar
1997-12-01  0:00                       ` Joe Gwinn
1997-12-01  0:00                         ` Robert Dewar
1997-12-01  0:00                           ` Joe Gwinn
1997-12-03  0:00                           ` robin [this message]
1997-11-25  0:00             ` Matthew Heaney
1997-11-26  0:00             ` William A Whitaker
1997-11-24  0:00     ` Geert Bosch
1997-11-23  0:00   ` Tom Moran
1997-11-25  0:00     ` John A. Limpert
1997-11-25  0:00       ` Robert Dewar
1997-11-25  0:00       ` Robert Dewar
1997-11-24  0:00 ` Vince Del Vecchio
1997-11-24  0:00 ` Vince Del Vecchio
1997-12-03  0:00 ` robin
     [not found] <9711221603.AA03295@nile.gnat.com>
1997-11-22  0:00 ` Ken Garlington
  -- strict thread matches above, loose matches on Subject: below --
1997-11-27  0:00 tmoran
1997-11-27  0:00 ` Robert Dewar
1997-11-29  0:00   ` Tarjei T. Jensen
1997-11-28  0:00 tmoran
1997-11-28  0:00 ` Robert Dewar
1997-12-02  0:00 Robert Dewar
1997-12-02  0:00 ` Joe Gwinn
1997-12-02  0:00   ` Ken Garlington
1997-12-03  0:00     ` Joe Gwinn
1997-12-04  0:00       ` Robert Dewar
1997-12-04  0:00         ` Shmuel (Seymour J.) Metz
1997-12-02  0:00   ` Robert Dewar
1997-12-02  0:00     ` Matthew Heaney
1997-12-03  0:00       ` Robert Dewar
1997-12-03  0:00     ` robin
1997-12-03  0:00       ` Robert Dewar
1997-12-03  0:00     ` Shmuel (Seymour J.) Metz
1997-12-03  0:00       ` Robert Dewar
1997-12-03  0:00       ` Matthew Heaney
1997-12-04  0:00         ` Shmuel (Seymour J.) Metz
1997-12-04  0:00           ` Robert Dewar
1997-12-03  0:00       ` Robert Dewar
1997-12-03  0:00 ` robin
2011-09-29 10:25 RasikaSrinivasan@gmail.com
2011-09-29 10:49 ` AdaMagica
2011-09-29 13:38   ` Martin
2011-09-30 10:17 ` Stephen Leake
2011-09-30 16:25   ` tmoran
2011-09-30 16:52     ` Dmitry A. Kazakov
2011-10-01 11:09     ` Stephen Leake
2011-09-30 19:26   ` tmoran
2011-09-30 22:31   ` tmoran
2011-10-01 13:37   ` RasikaSrinivasan@gmail.com
2011-10-02 14:19     ` Stephen Leake
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