From mboxrd@z Thu Jan  1 00:00:00 1970
X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me
X-Spam-Level: 
X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00
	autolearn=unavailable autolearn_force=no version=3.4.4
Path: 
 eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!news.eternal-september.org!mx02.eternal-september.org!.POSTED!not-for-mail
From: Nicholas Collin Paul de Gloucester <wirklich@nicht.at>
Newsgroups: comp.lang.ada
Subject: Re: Everything You Know Is Wrong
Date: Mon, 28 Dec 2015 19:50:31 +0100
Organization: A noiseless patient Spider
Message-ID: <alpine.DEB.2.11.1512281938090.14144@Lydia.insomnia247.nl>
References: <n5nbml$v32$1@dont-email.me> <n5r0su$lts$1@dont-email.me>
 <n5r5sb$sgs$1@speranza.aioe.org>
 <alpine.DEB.2.11.1512281721030.14144@Lydia.insomnia247.nl>
 <n5rrjq$gg3$1@speranza.aioe.org>
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed
Injection-Info: mx02.eternal-september.org;
 posting-host="1b4315c307f3cc5ba77928d0bb2ed33c";
	logging-data="9797"; mail-complaints-to="abuse@eternal-september.org";
	posting-account="U2FsdGVkX19MYTPfh+fQkUuJ98gDp9+Wca8JtA/AwF8vSvY2KKG6zA=="
User-Agent: Alpine 2.11 (DEB 23 2013-08-11)
In-Reply-To: <n5rrjq$gg3$1@speranza.aioe.org>
Cancel-Lock: sha1:gm0bt9R5uiEfyU3r0rkW/Y7xQEw=
X-X-Sender: gloucester@Lydia.insomnia247.nl
Xref: news.eternal-september.org comp.lang.ada:28913
Date: 2015-12-28T19:50:31+01:00
List-Id: <comp.lang.ada>

On December 28th, 2015, Dmitry A. Kazakov posted:
|----------------------------------------------------------------------------|
|"On 2015-12-28 17:27, Nicholas Collin Paul de Gloucester wrote:             |
|                                                                            |
|> Reducing energy consumption is not a novel ideal. E.g. I quote from a     |
|> review by me of Petru Eles; Krzysztof Kuchcinski; and Zebo Peng,          |
|> "System Synthesis with VHDL", Kluwer Academic Publishers (                |
|>    WWW.ACCU.org/index.php?module=bookreviews&func=search&rid=1291 )       |
|> which was published in "CVu", Volume 16, Number 2:                        |
|> "[. . .]                                                                  |
|>                                                                           |
|> I learnt from the low-power synthesis chapter that two's complement is    |
|> believed to consume more power than sign-magnitude due to the high        |
|> level of switching needed if a variable/signal toggles between            |
|> positive and negative often.                                              |
|                                                                            |
|That is not the goal of energy saving agenda, which is doing less           |
|computations, e.g. by turning off some circuits or reducing frequency. I    |
|don't think anybody would seriously consider this an advantage. From the SW |
|POV it is only more complexity, less safety etc.                            |
|                                                                            |
|--                                                                          |
|Regards,                                                                    |
|Dmitry A. Kazakov                                                           |
| http://www.dmitry-kazakov.de "                                             |
|----------------------------------------------------------------------------|

What is "this"?

If "this" would be a reification of an integer type which would not be
two's complement, then alternative reifications are of interest:
e.g. sign-magnitude as documented by Eles; Kuchcinski; and Peng for
saving energy; or Gray code for a different motivation.

If "this" would be "turning off some circuits", then witness clock
gating.

If "this" would be "reducing frequency", then there would also be
cases of this.

Happy New Year.

Regards,
Nicholas Collin Paul de Gloucester