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,FREEMAIL_FROM autolearn=unavailable autolearn_force=no version=3.4.4 X-Received: by 10.107.1.8 with SMTP id 8mr6558678iob.138.1510326680334; Fri, 10 Nov 2017 07:11:20 -0800 (PST) X-Received: by 10.157.14.201 with SMTP id 67mr384591otj.4.1510326680254; Fri, 10 Nov 2017 07:11:20 -0800 (PST) Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!border1.nntp.ams1.giganews.com!border2.nntp.ams1.giganews.com!nntp.giganews.com!peer02.ams1!peer.ams1.xlned.com!news.xlned.com!peer02.am4!peer.am4.highwinds-media.com!peer02.iad!feed-me.highwinds-media.com!news.highwinds-media.com!l196no64324itl.0!news-out.google.com!193ni3024iti.0!nntp.google.com!186no59491itu.0!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.lang.ada Date: Fri, 10 Nov 2017 07:11:20 -0800 (PST) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=173.71.208.22; posting-account=QF6XPQoAAABce2NyPxxDAaKdAkN6RgAf NNTP-Posting-Host: 173.71.208.22 References: User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <94c0c879-6a6b-499e-82e2-f8a5c84f42a3@googlegroups.com> Subject: Re: Comparing Access Types From: Jere Injection-Date: Fri, 10 Nov 2017 15:11:20 +0000 Content-Type: text/plain; charset="UTF-8" X-Received-Body-CRC: 3104364441 X-Received-Bytes: 2513 Xref: feeder.eternal-september.org comp.lang.ada:48802 Date: 2017-11-10T07:11:20-08:00 List-Id: On Friday, November 10, 2017 at 3:35:10 AM UTC-5, Dmitry A. Kazakov wrote: > On 09/11/2017 23:38, Robert A Duff wrote: > > "Dmitry A. Kazakov" writes: > > > >> ...Actually even equality cannot > >> be for segmented memory but it felt good enough. > > > > ? > > > > "=" returns True if two access values designate the same object, > > which is a well defined concept, and has nothing to do with > > segmented memory. And it's easy to implement, whether memory > > is segmented or not. > > You could have two segments mapped to the same physical memory. Then you > may have two unequal segmented addresses pointing to the same physical > memory unit and so "=" will lie. > > -- > Regards, > Dmitry A. Kazakov > http://www.dmitry-kazakov.de I know that a lot of the embedded C compilers that we use overcome this issue by encoding unique segment information into their pointers. So a pointer isn't just a physical address, but something more that expresses a unique location based on physical memory location + whatever other information is available. I don't know enough about Ada compilers, but my expectation is that they could also solve that problem (maybe the same way or maybe in a better way).