From: "Randy Brukardt" <randy@rrsoftware.com>
Subject: Re: Comparing Access Types
Date: Wed, 15 Nov 2017 19:17:46 -0600
Date: 2017-11-15T19:17:46-06:00 [thread overview]
Message-ID: <ouiovq$g6l$1@franka.jacob-sparre.dk> (raw)
In-Reply-To: wccinei14g6.fsf@TheWorld.com
"Robert A Duff" <bobduff@TheWorld.com> wrote in message
news:wccinei14g6.fsf@TheWorld.com...
>I wrote:
>
>> If "=" lies, then the Ada implementation is simply wrong.
>
> There were more than one Ada compiler for the 8086,
> and I'm pretty sure "=" on access values worked
> properly. It's really not hard to get it right -- in
> fact I think the compiler would have to go out of
> it's way to get it wrong.
I doubt that. It wouldn't have worked "right" in Janus/Ada, for instance, we
just did a binary comparison. So
C000:DEAD /= CDEA:000D even though they pointed at the same physical
memory.
But you could only run into that if you converted a System.Address into an
access value; it would never happen within a correctly running Ada program
so we didn't want to pay the extra cost of doing it perfectly right. (Same
reason that I'd never waste time [mine or a programs] making zero-size
objects work *right* in this sense.)
Randy.
next prev parent reply other threads:[~2017-11-16 1:17 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-09 5:37 Comparing Access Types Jere
2017-11-09 8:29 ` Simon Wright
2017-11-09 8:33 ` Dmitry A. Kazakov
2017-11-09 22:38 ` Robert A Duff
2017-11-10 8:35 ` Dmitry A. Kazakov
2017-11-10 15:11 ` Jere
2017-11-10 16:05 ` Robert A Duff
2017-11-10 16:30 ` Robert A Duff
2017-11-16 1:17 ` Randy Brukardt [this message]
2017-11-18 22:01 ` Robert A Duff
2017-11-20 22:25 ` Randy Brukardt
2017-11-21 0:30 ` Shark8
2017-11-21 8:57 ` Dmitry A. Kazakov
2017-11-22 1:01 ` Randy Brukardt
2017-11-10 15:20 ` Jere
2017-11-10 16:00 ` Robert A Duff
2017-11-10 16:22 ` Jere
2017-11-10 15:06 ` Jere
2017-11-16 1:21 ` Randy Brukardt
2017-11-16 1:13 ` Randy Brukardt
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