Article View: comp.arch
Article #3178Re: Uses for unusual instructions
From: Peter Desnoyers
Date: Tue, 28 Nov 1989 17:27
Date: Tue, 28 Nov 1989 17:27
27 lines
1893 bytes
1893 bytes
In article <1989Nov27.173555.19673@fxgrp.fx.com> mikew@fxgrp.fx.com (Mike
Wexler) writes:
> >cik@l.cc.purdue.edu (Herman Rubin) writes:
> >Soem time ago, I posted to this group certain instructions which are
cheap
> >in hardware and expensive in software. I wish to discuss these and give
> >partial examples; the full examples are too lengthy and would provide
> >little insight.
> It sounds like some special purpose hardware might help solve your problems
> ^^^^
> more quickly. I propose an experiment:
> 1. Design a CPU with these instructions added and one without(you might be
> able to start with some kind of publicly available designs from a
> university project).
> 2. Modify your codes to take advantage of these instructions. Run your code
> through a good simulator and see how much perfomance you gain.
alternately:
Assume that a memory-mapped I/O device exists that takes data in (and
possibly instruction bits on the low-order address lines), implements your
instructions, and can return results on the next memory read cycle.
Simulate performance of your code with this hardware. If it gives you a
big boost, implement it in a programmable chip and put it in your system.
Peter Desnoyers
Apple ATG
(408) 974-4469
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!samsung!brutus.cs.uiuc.edu!apple!apple.com!desnoyer From: desnoyer@apple.com (Peter Desnoyers) Newsgroups: comp.arch Subject: Re: Uses for unusual instructions Message-ID: <5446@internal.Apple.COM> Date: 28 Nov 89 17:27:12 GMT Sender: usenet@Apple.COM Organization: Apple Computer, Inc. Lines: 27 References: <1743@l.cc.purdue.edu> <1989Nov27.173555.19673@fxgrp.fx.com>