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From: Simon Clubley <clubley@remove_me.eisner.decus.org-Earth.UFP>
Newsgroups: comp.lang.ada
Subject: Re: Forcing GNAT to use 32-bit load/store instructions on ARM?
Date: Wed, 2 Jul 2014 16:49:11 +0000 (UTC)
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Date: 2014-07-02T16:49:11+00:00
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On 2014-07-01, Niklas Holsti <niklas.holsti@tidorum.invalid> wrote:
> On 14-07-02 00:20 , Simon Clubley wrote:
>> 
>> When c.l.a talked a few weeks ago about syntax for the atomic update
>> of multiple bitfields at the same time, I had thought the general
>> view was that Atomic on a record resulted in register updates in units
>> of the record size when updating a single bitfield, but that's clearly
>> not the case as you have just pointed out.
>
> As I remember, the new syntax ideas in that discussion were meant to
> update some bitfields in an atomic record as part of a read, modify,
> write sequence, accessing the whole record without using a temporary
> variable to hold the value. So Ada's rule for Atomic was included and
> assumed in that discussion.

Yes, you are correct. Thinking about it, this interpretation of Ada's
Atomic rule is still consistent with that discussion because the
underlying reference is to the _full_ record in those proposals.

> I am ashamed for forgetting it... maybe
> there have been too many midnight-football-viewing sessions lately :-)
>

:-)

Simon.

-- 
Simon Clubley, clubley@remove_me.eisner.decus.org-Earth.UFP
Microsoft: Bringing you 1980s technology to a 21st century world