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!news.eternal-september.org!feeder.eternal-september.org!newsfeed.datemas.de!enother.net!enother.net!enother.net!peer01.fr7!futter-mich.highwinds-media.com!news.highwinds-media.com!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: Niklas Holsti Newsgroups: comp.lang.ada Subject: Re: Ada 2012 Constraints (WRT an Ada IR) Date: Wed, 7 Dec 2016 08:36:18 +0200 Organization: Tidorum Ltd Message-ID: References: <47366b42-c0a3-41bf-a44a-5241c109d60f@googlegroups.com> <58f477d2-8b01-4001-bad8-47ea73424f4c@googlegroups.com> <6e206c3b-d4a8-44ab-9e0e-adb0924983ef@googlegroups.com> <10e8cb52-1cbd-40ed-ba11-f474c2263ced@googlegroups.com> <84oe4cdv010g9fba0jrjv2os7c0halucd0@4ax.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Trace: individual.net MvwqGndSS5uh6x5i5gURWQWxP8dLQCdKgj5QQacegsDD6gfj2W Cancel-Lock: sha1:S+K5vF4uXq2F3a5jXxaPTiy51PM= User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 In-Reply-To: <84oe4cdv010g9fba0jrjv2os7c0halucd0@4ax.com> X-Received-Bytes: 2698 X-Received-Body-CRC: 3142279518 Xref: news.eternal-september.org comp.lang.ada:32647 Date: 2016-12-07T08:36:18+02:00 List-Id: On 16-12-07 03:08 , Dennis Lee Bieber wrote: > On Tue, 6 Dec 2016 13:44:27 -0800 (PST), Shark8 > declaimed the following: > >> >> One reason that an IR could be handy is as an execution model -- like how Intel's iAPX 432 was designed for Ada's feature-set -- having a generalized form for constraints/violations would mean that the the chip would only have to handle one kind of constraint-type instead of having to have specialized forms for P3 and P0. >> > With modern processor silicon, the iAPX432 might almost run fast enough > to be usable. > > (Was a nice idea -- but the overhead of all the protection handling > bogged it down too much to get a foot-hold, or even a hand-hold ) There's a new processor architecture in development called "the Mill", which has a lot of protection built-in, but promises to be fast, at least in the computation-per-watt measure. See http://millcomputing.com/. I don't know enough about the iAPX432 to compare the protection levels, but it seems that the Mill will catch a lot of the common protection violations and other undefined behaviour in C programs. The Mill looks like a very good processor for Ada, for example all operations on integers have variants that wrap around, saturate, or trap, on over/underflow. -- Niklas Holsti Tidorum Ltd niklas holsti tidorum fi . @ .