comp.lang.ada
 help / color / mirror / Atom feed
From: mheaney@ni.net (Matthew Heaney)
Subject: Re: fixed point vs floating point
Date: 1997/11/22
Date: 1997-11-22T00:00:00+00:00	[thread overview]
Message-ID: <mheaney-ya023680002211972146020001@news.ni.net> (raw)
In-Reply-To: dewar.880248826@merv


In article <dewar.880248826@merv>, dewar@merv.cs.nyu.edu (Robert Dewar) wrote:


>Sure if you never do multiplications, then the penalty for fixed-point
>can be close to zero (compared with flaoting-point), unless of course
>you want more than 32 bits of precision and you are on a 32 bit machine,
>then fixed-point gets very expensive.

Let's change the problem a bit.  What's more expensive: to calculate the
sine of a fixed point with a binary small, or to calculate the sine of a
floating point?  What about making the fixed point 32 bits instead of 64 -
will that make it more efficient?

That processor Intermetrics is building an Ada compiler for (SHARC, or
something like that) comes with "fixed point math in hardware."  Will that
make any difference in efficiency?

BTW: how do I calculate the sine of a fixed point number?

--------------------------------------------------------------------
Matthew Heaney
Software Development Consultant
<mailto:matthew_heaney@acm.org>
(818) 985-1271




  reply	other threads:[~1997-11-22  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 [this message]
1997-11-23  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
1997-11-23  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
1997-11-25  0:00             ` Matthew Heaney
1997-11-26  0:00             ` William A Whitaker
1997-11-24  0:00     ` Geert Bosch
1997-11-24  0:00 ` Vince Del Vecchio
1997-11-24  0:00 ` Vince Del Vecchio
1997-12-03  0:00 ` robin
  -- strict thread matches above, loose matches on Subject: below --
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
1997-12-02  0:00 Robert Dewar
1997-12-02  0:00 ` Joe Gwinn
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     ` 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
1997-12-03  0:00       ` Robert Dewar
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
1997-12-03  0:00 ` robin
1997-11-28  0:00 tmoran
1997-11-28  0:00 ` Robert Dewar
1997-11-27  0:00 tmoran
1997-11-27  0:00 ` Robert Dewar
1997-11-29  0:00   ` Tarjei T. Jensen
     [not found] <9711221603.AA03295@nile.gnat.com>
1997-11-22  0:00 ` Ken Garlington
replies disabled

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox