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From: Ludovic Brenta <ludovic@ludovic-brenta.org>
Newsgroups: comp.lang.ada
Subject: Re: GNAT 4.8 atomic access to 64-bit objects
Date: Thu, 14 Nov 2013 21:34:26 +0100
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Date: 2013-11-14T21:34:26+01:00
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"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> writes:
> The following does not compile anymore for 32-bit Linux targets, e.g. under
> Debian:
>
> procedure Test is
>    type T is mod 2**64;
>    X : T;
>    pragma Atomic (X); -- Error
> begin
>    null;
> end Test;
>
> The above seems no more legal, because the compiler does not support
> atomic access to X.
>
> Is there a way to change this without machine code insertions?

Even with machine code insertions, I fail to see how a 32-bit processor
can accept 64-bit integers as atomic.

I'd suggest you use 64-bit floating-point registers instead; i386
processors have them, I think.  That has been a useful trick for a
decade or so :)

-- 
Ludovic Brenta.