Re: Forcing GNAT to use 32-bit load/store instructions on ARM?

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Tue, 1 Jul 2014 17:00:45 +0000 (UTC), Simon Clubley wrote:

> On 2014-07-01, Dmitry A. Kazakov <mailbox@dmitry-kazakov.de> wrote:
>> On Tue, 1 Jul 2014 12:09:36 +0000 (UTC), Simon Clubley wrote:
>>
>>> On 2014-07-01, Dmitry A. Kazakov <mailbox@dmitry-kazakov.de> wrote:
>>>> On Mon, 30 Jun 2014 15:11:31 -0700 (PDT), daniel.dmk@googlemail.com wrote:
>>>>> Things I have tried:
>>>>> 1) Using the Atomic aspect on the record type and CR object had no effect
>>>>> on the code generated.
>>>>
>>>> Yes, I hope they will fix this for this and other platforms, e.g. 64-bit
>>>> atomic load/store for i686.
>>> 
>>> Are you saying Pragma Atomic is known to be broken in GNAT ?
>>
>> It is not broken. The problem I know is that it is rejected on machines
>> that do support atomic load and store.
>>
> 
> That's not great, but at least you know there's a problem at compile
> time.
> 
> In the OP's case (according to the problem description), pragma Atomic
> was been accepted, but the generated code was not using a 32-bit store
> and was using an 8-bit store into a 32-bit field instead.

Yes, my case was different. The pragma was rejected.

> If for some reason the compiler could not generate a 32-bit str opcode
> instead of an 8-bit strb opcode, the pragma Atomic should have caused
> an error during compilation.

Well, pragmas are permitted to be ignored. Atomic should never be a pragma.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de